the Analyst The Voice of the Water Treatment Industry
Volume 26 Number 1
1300 Piccard Drive, Suite LL 14 • Rockville, MD 20850
Winter 2019
What Are Practical Approaches to Improve RO Technology? Part 1: Keys to Successful IX Resin Storage Can Hydrophobic Modifications to Polymers Achieve Better Carbonate Scale Control? Volume 26 Number 1 Winter 2019
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Winter 2019
Volume 26
Number 1
10 What Are Practical Approaches to Improve RO Technology?
Michael Boyd, Desalitech Inc. Reverse osmosis (RO) is the primary technology used in the desalination of industrial water and treating wastewater for reuse. Although the technology is very effective at removing salts, it has many limitations and pain points associated with its operation. These include low recovery rates, fouling and membrane scaling, high clean-in-place (CIP) frequencies, short membrane life, difficulty in managing variations in feedwater quality, compromised permeate quality, and high operating costs, among others. The key to solving all of these issues ultimately comes down to thinking outside the box and reinventing the basic filtration process starting from scratch.
4
Calendar of Events
6
President’s Message
8
Message From the President-Elect
50 Industry Notes 54 Association News
26 Part 1: Keys to Successful IX Resin Storage
Peter Meyers, ResinTech Inc. Generally, ion exchange (IX) resins may be safely stored for two to five years (or longer) without significant chemical or physical deterioration. Numerous exceptions exist, and salt-form resins (neutral pH) store better than hydrogen (H) or hydroxide (OH) forms. Indoor climate-controlled storage in the original shipping containers is ideal. Precautions should always be taken to store IX resins in their original undamaged shipping containers. These should be kept in sheltered, reasonably well-ventilated areas, protected from extremes of heat or cold and from rain or other forms of moisture. Following these precautions, there is little or no concern regarding the shelf life of the stored resins. So, with reasonable care, IX resins can be stored for five years or longer without any ill effects.
34 Can Hydrophobic Modifications to Polymers Achieve Better Carbonate Scale Control?
Klin Rodrigues, Ph.D., and Jan Sanders, Nouryon (formerly AkzoNobel) It is a known fact that nonionic modifications of polymers improve scale control performance. These nonionic modifications can be hydrophilic or hydrophobic. The role of hydrophobic modifications of polymers for carbonate scale control has not yet been widely studied. This article will investigate the impact of hydrophobic substitutions of polymers for carbonate scale control in cooling water systems.
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56 Membership Benefits 58 T.U.T.O.R. 66 Making a Splash 67 CWT Spotlight 68 Ask the Experts 69 Capital Eyes 70 Financial Matters 72 Business Notes 74 Advertising Index
the Analyst Volume 26 Number 1
1300 Piccard Drive, Suite LL 14 Rockville, MD 20850 (301) 740-1421 • (301) 990-9771 (fax) www.awt.org
2019 AWT Board of Directors President
David Wagenfuhr
President-Elect
Secretary
Michael Bourgeois, CWT
Treasurer
2019 Technical Training West
East
March 27–30, 2019 Hotel Annapolis Annapolis, Maryland
2019 Annual Convention & Exposition
Matt Jensen, CWT
Immediate Past President
September 11–14, 2019 Palm Springs Convention Center and Renaissance Hotel Palm Springs, California
Marc Vermeulen, CWT
Directors
Steven Hallier, CWT Stephanie Keck, CWT Andy Kruck, CWT Bonnee Randall
2020 Annual Convention & Exposition
Ex-Officio Supplier Representative
Garrett S. Garcia
Past Presidents
Association Events February 27–March 2, 2019 DoubleTree San Diego–Mission Valley San Diego, California
Thomas Branvold, CWT
Jack Altschuler John Baum, CWT R. Trace Blackmore, CWT, LEED AP D.C. “Chuck” Brandvold, CWT Brent W. Chettle, CWT Dennis Clayton Bernadette Combs, CWT, LEED AP Matt Copthorne, CWT James R. Datesh John E. Davies, CWT Jay Farmerie, CWT Gary Glenna Charles D. Hamrick Jr., CWT Joseph M. Hannigan Jr., CWT
Calendar of Events
Mark R. Juhl Brian Jutzi, CWT Bruce T. Ketrick Jr., CWT Bruce T. Ketrick Sr., CWT Ron Knestaut Robert D. Lee, CWT Mark T. Lewis, CWT Steven MacCarthy, CWT Anthony J. McNamara, CWT James Mulloy Alfred Nickels Scott W. Olson, CWT William E. Pearson II, CWT William C. Smith Marc Vermeulen, CWT Casey Walton, B.Ch.E, CWT Larry A. Webb
Staff
Executive Director
Heidi J. Zimmerman, CAE
Deputy Executive Director
Sara L. Wood, MBA, CAE
Senior Member Services Manager
Angela Pike
Vice President, Meetings
Grace L. Jan, CMP, CAE
Meetings Manager
Morgan Prior
Exhibits and Sponsorship Manager
Barbara Bienkowski, CMP
Exhibits and Sponsorship Associate Manager
Brandon Lawrence
Marketing Director
Julie Hill
Production Manager
Jennifer Olivares
Website Manager
Jeyin Lee
Technical Writer/Copy Editor Lynne Agoston
Accountant
September 30–October 3, 2020 Louisville Convention Center and Omni Hotel Louisville, Kentucky
2021 Annual Convention & Exposition
September 22–25, 2021 Providence Convention Center and Omni Hotel Providence, Rhode Island
2022 Annual Convention & Exposition September 21–24, 2022 Vancouver Convention Centre Vancouver, Canada
2023 Annual Convention & Exposition
October 4–7, 2023 Grand Rapids Convention Center and Amway Grand Hotel Grand Rapids, Michigan
Also, please note that the following AWT committees meet on a monthly basis. All times shown are Eastern Time. To become active in one of these committees, please contact us at (301) 740-1421. Second Tuesday of each month, 11:00 am – Legislative/Regulatory Committee Second Tuesday of each month, 2:30 pm – Convention Committee Second Wednesday of each month, 11:00 am – Business Resources Committee Second Friday of each month, 10:00 am – Special Projects Subcommittee Second Friday of each month, 11:00 am – Cooling Subcommittee Second Friday of each month, 2:00 pm – Pretreatment Subcommittee Third Monday of each month, 9:00 am – Certification Committee Third Monday of each month, 3:30 pm – Young Professionals Task Force Third Tuesday of each month, 3:00 pm – Education Committee Third Friday of each month, 9:00 am – Boiler Subcommittee Third Friday of each month, 10:00 am – Technical Committee Quarterly (call for meeting dates), 11:00 am – Wastewater Subcommittee
Dawn Rosenfeld
The Analyst Staff Publisher
Heidi J. Zimmerman, CAE
Managing Editor
Lynne Agoston
Technical Editor
Michael Henley (303) 324-9507 mdhenleywater@gmail.com
Advertising Sales
Other Industry Events
CTI, Annual Conference, February 5–9, 2019, New Orleans, Louisiana ASHE, PDC Summit, March 17–20, 2019, Phoenix, Arizona NACE, Corrosion Conference & Expo, March 24–28, 2019, Nashville, Tennessee ACS, Spring National Meeting & Expo, March 31–April 4, 2019, Orlando, Florida WQA, Aquatech Meeting, April 23–26, 2019, Las Vegas, Nevada
Heather Prichard advertising@awt.org The Analyst is published quarterly as the official publication of the Association of Water Technologies. Copyright 2019 by the Association of Water Technologies. Materials may not be reproduced without written permission. Contents of the articles are the sole opinions of the author and do not necessarily express the policies and opinions of the publisher, editor or AWT. Authors are responsible for ensuring that the articles are properly released for classification and proprietary information. All advertising will be subject to publisher’s approval, and advertisers will agree to indemnify and relieve publisher of loss or claims resulting from advertising contents. Editorial material in the Analyst may be reproduced in whole or part with prior written permission. Request permission by writing to: Editor, the Analyst, 1300 Piccard Drive, Suite LL 14, Rockville, MD 20850, USA. Annual subscription rate is $100 per year in the U.S. (4 issues). Please add $25 for Canada and Mexico. International subscriptions are $200 in U.S. funds.
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the Analyst Volume 26 Number 1
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President’s Message
By David Wagenfuhr
•
At AWT, we define ourselves by holding onto our principles and values while embracing the excitement of the future. With this in mind, in November 2018, the board of directors approved a new strategic plan to guide AWT. The plan reflects the collaborative efforts of the entire AWT community and the aspirations of that community for our great association.
•
We hope you will share our excitement for the AWT strategic plan and that you will join us as we begin to implement that plan. This is an exciting time in our history, and an opportunity to engage the entire AWT community in building the future for this remarkable association. We encourage you to get involved and help us as we work to achieve our outcomes.
AWT is focusing on four strategic outcomes. •
•
•
•
Outcome 1—Training and Education: AWT’s membership heavily utilizes the premier business and technical resources for the water treatment industry through technologically advanced delivery mechanisms. Outcome 2—Member and Industry Advocate: AWT is the recognized advocate for the water treatment industry, including creating a workforce pipeline, and is known for its contributions by members, the public, and especially the younger generation. Outcome 3—An Engaged Membership: AWT has increased its membership and is known for enhanced communication that encourages a diverse, engaged membership to continuously design a relevant association. Outcome 4—Charity Focused on Water: AWT demonstrates its commitment to global clean water as “the first environmentalists” through its charitable pursuits related to water.
I would also like to remind you of two upcoming events happening in the coming months.
Benchmarking Survey
The data from the financial benchmarking survey is crucial to all water treatment companies, and your participation is critical to our having current information on our industry. In addition to obtaining complimentary survey results, participants will also receive a complimentary STEM kit they can use at their local school. Be sure to participate in the survey.
AWT Training
AWT Training will be held February 27–March 2 in San Diego, California, and March 27–30 in Annapolis, Maryland. Every year, the sessions are revised and updated based on feedback received from attendees. Programs include Sales, RO, Fundamentals and Applications, Wastewater (San Diego Only), and Water Treatment training sessions. Sign up now at www.awt.org.
By focusing on the strategic outcomes: • •
AWT will be training the water treatment workforce of the future. AWT’s members will be valued for the service they provide, not just the products they provide.
The water treatment community will continue to be engaged in the important work of resource conservation and responsibility. We will support the excellence of our members and the dedication of the volunteers that characterize AWT.
As always, I welcome your feedback and can be reached at president@awt.org.
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the Analyst Volume 26 Number 1
Bio-Source is a specialty consulting, toll blender, repackager and distributor of EPA registered non-oxidizing and oxidizing biocides. We also distribute a wide range of raw materials commonly used to formulate boiler and cooling water products. All biocides can be resold under the manufacturer’s label or private labeled through a subregistration. All private labels will be printed and maintained current with EPA by Bio-Source.
RAW MATERIALS
BIOCIDES Bromicide Tablets ( BCDMH ) Bromicide Granules Sodium Bromide ( 40 % ) Stabilized Liquid Bromine Trichlor / NaBr Dichlor / NaBr DBNPA ( 20 % ) DBNPA ( 5 % ) DBNPA Tablets ( 40 % ) Glutaraldehyde ( 50, 45, 25, 15 % ) Glut / Quat Blends Isothiazolin ( 1.5 % ) Isothiazolin ( 1.5 % Cu Free ) Isothiazolin / Bronopol Blend Terbutylazine ( 4 % ) TTPC ( 5 % ) TTPC / WSCP ( 5 % ) WSCP ( 60 % ) THPS, Various Concentrations Hydrogen Peroxide / Silver Blends
PMA & PAA Maleic acid Copolymers / Terpolymers PCA PCA / AMPS POCA AA / AMPS ATMP HEDP PBTC TTA ( 50 % ) The Copper Bullet ( TT / BZT / HTT ), 38 % Cyclohexylamine DEAE Morpholine DEHA Sodium Molybdate Dihydrate Sodium Molybdate Crystals Carbohydrazide Erythorbic acid SPECIALTY PRODUCT DTEA IITM Biodispersant
VOLUME DISCOUNT PRICING IN BOTH PAILS AND DRUMS MULTIPLE STOCKING LOCATIONS IN BUSINESS SINCE 1991 www.biosourceinc.com john@biosourceinc.com
P.O. Box 2386 * Dacula, GA 30019
Integrity in Life. Integrity in Business.
* 770 / 978-1443 * ( FAX ) 770-978-4165
Message From the President-Elect
By Tom Brandvold, CWT
Educational Program
If you are like me, your life orbits around water. Beyond being a necessity, water is what we do. Its use and misuse create opportunities for all of us. Do you ever stop and wonder how something as simple as a couple hydrogen atoms and an oxygen atom can be so complex? How can a molecule with an atomic mass of 17 and only nine electrons be a universal solvent and absorb, store, and release heat better than almost anything and exist in all three physical states at the temperatures we encounter on Earth? Therein lies the Magic of Water, our theme for the 2019 Annual Convention & Exposition.
We have received a record number of abstracts for this year’s convention. We will have a solid program with quality sessions, including more panel discussions and educational workshops.
Golf Tournament
Palm Springs, California, will be the place to be September 11–14, as the water treatment industry gathers for robust technical and educational sessions, the tradeshow, and networking and social functions.
The golf tournament will be held at Indian Wells Golf Resort—one of the few properties to have two courses ranked in the Top 25 “Best Municipal Courses in the United States” by Golfweek Magazine. In addition to spectacular mountain views, the par-72 Celebrity Course features breathtaking fairways and flowing water in the form of streams, brooks, and split-level lakes connected by striking waterfalls, with vibrant floral detail. This course is unrivaled in beauty and playability. From start to finish, the Celebrity Course offers an unmatched golf experience. You won’t want to miss the chance to play at this incredible location.
Keynote Address
Annual Reception and Awards Dinner
Our keynote address will be delivered by Ryan Oakes. With almost 20 years of experience performing as a magician and mentalist, Ryan is one of the country’s most sought-after corporate entertainers, averaging over 100 appearances per year. A decorated veteran in the field of magic, Ryan is the youngest person ever to win the Society of American Magicians’ National Magic Competition, one of the highest honors in magic. Since then, Ryan has performed at literally thousands of events, including an appearance at the White House. Ryan will help us understand the importance of having a WOW factor in our dealings with customers and prospects. He will also touch on techniques we can all use in client negotiations.
We’re also looking forward to a great Annual Reception and Awards Dinner, which will again take place on Thursday evening to allow more people to celebrate with us. We’ll be celebrating in style this year, with a red-carpet magical event. It will be a fun time and a nice way to honor our award recipients and include entertainment from Ryan Oakes. Mark your calendars now for the 2019 Annual Convention & Exposition! As we plan and prepare for Palm Springs, I welcome your input and feedback. I can be reached at carmac@premierwater.com.
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the Analyst Volume 26 Number 1
West February 27–March 2, 2019 DoubleTree San Diego–Mission Valley San Diego, California
East March 27–30, 2019 Hotel Annapolis Annapolis, Maryland
Training Available Polymeric-Membrane Separation Technologies RO/Ultrafiltration Training: This one-day indepth course is suited for anyone looking for a better understanding of reverse osmosis, ultrafiltration, EDI, or related membrane technologies. Sales Training: This interactive “how to” session will give you the practical knowledge you will need to develop yourself, your business, and your brand. Fundamentals and Applications Training: The Fundamentals and Applications course is designed for service technicians new to the industry. This highly interactive class brings the mechanical room into the classroom and focuses on real-world examples; attendees learn directly from leaders in the industry as well as their peers. Water Treatment Training: This intensive three-day training covers regulatory and safety issues, water chemistry and testing, calculations, boiler water treatment, cooling water chemistry, and much more. Wastewater Treatment (San Diego Only): This comprehensive three-day course, only offered in San Diego, will cover all aspects of wastewater treatment, including influent and effluent clarification, solids removal and dewatering, chemical application, and how to screen products for application.
Sign up today at www.awt.org
9
the Analyst Volume 26 Number 1
What Are Practical Approaches to Improve RO Technology? Michael Boyd, Desalitech Inc.
Reverse osmosis (RO) is the primary technology used in the desalination of industrial water and treating wastewater for reuse. Although the technology is very effective at removing salts, it has many limitations and pain points associated with its operation. These include low recovery rates, fouling and membrane scaling, high clean-in-place (CIP) frequencies, short membrane life, difficulty in managing variations in feedwater quality, compromised permeate quality, and high operating costs, among others. The key to solving all of these issues ultimately comes down to thinking outside the box and reinventing the basic filtration process starting from scratch. In traditional multistage RO systems, recovery, flux and crossflow are coupled, so managing efficiency and performance is a balancing act. The systems are either reliable, but inefficient, or efficient, but unreliable. There are ways to optimize this balancing act using hybrid-staging or inter-stage booster pumps. However, this comes at the sacrifice of operational flexibility. While the industry has made significant advancements to individual aspects of the RO process (i.e., membrane elements, variable frequency drive [VFD] pump motors, and analytical equipment), none of these advancements have come from optimization of the fundamental design.
beverage company reduced its water footprint and costs while meeting corporate sustainability goals. Case Study 2 reviews how a paper mill in the Sonoran Desert was able to double production, extend CIP frequency, and reduce energy and chemical costs. In Case Study 3, we will examine how a Fortune 50 company in the Midwest was able to adapt to a variable feedwater to meet stringent ingredient water specifications. Case Study 4 examines how a Southern Californian a power company upgraded all their peaking power plants to increase reliability and reduce operational costs by 85%, saving more than $1 million at each plant. In Case Study 5 we will examine water treatment at a pharmaceutical facility, while Case Study 6 looks at treating wastewater for reuse by California municipal plants.
Closed Circuit RO
The CCRO processA (1–4) is illustrated in Figure 1. The system operates in two modes: closed circuit at 100% recovery and in plug flow or flushing mode at 15% to 50% recovery. A high-pressure pump (HPP) feeds a closed loop comprising a single-stage of membrane elements and a circulation pump (CP). Multiple pressure vessels are operated in parallel with short membrane arrays. Permeate is produced at a rate “In the past, the traditional multistage RO systems equal to the flowwould be designed and operated based on a single rate of the HPP. Brine is recirpoint in time, which was the worst-case condition culated without over the course of the year.� depressurization.
The mass adoption of a newly emerging closed circuit reverse osmosis (CCRO) technology across multiple industries represents a fundamental breakthrough in RO technology since its commercialization in the 1960s. The simple solution combines the benefits of dead-end filtration with the strengths of crossflow filtration. Using standard components configured in a single-stage design, recovery, flux, and crossflow are uncoupled with standard triggers to purge concentrate based on volumetric recovery, pressure, and/or conductivity. This flexibility provides a level of efficiency and reliability that can only be achieved with the CCRO process. In the next section, this article will examine how the technology works from a basic level before we examine six case studies. In Case Study 1, we will review how a
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When a desired recovery percentage is reached, brine is purged from the system, displaced by feedwater from the high-pressure pump in a single plug-flow (PF) sweep. Brine displacement is executed without stopping the high-pressure pump or the production of permeate. The system then returns to closed-circuit (CC) operation, during which there is no brine reject stream. As an example, when operating at 90% overall recovery, the system may be in CC mode for 20 minutes (min) and PF mode for 1.5 min. At 95% recovery, the system may be in CC mode for 40 min. and PF mode for 1.5 min. In addition to volumetric recovery, the brine flush valve can also be triggered to purge concentrate from the system the Analyst Volume 26 Number 1
What Are Practical Approaches to Improve RO Technology? continued
based on pressure or permeate/concentrate conductivity. Custom triggers can be incorporated, including permeate-silica concentration, permeate-nitrate concentration, and permeate-sodium concentration, among others.
Operating with multiple set-points provides the system the flexibility to automatically adapt to changing feedwater conditions, while always maximizing recovery relative to the desired permeate quality targets.
Figure 1: Illustration of the CCRO approach.
The overall recovery rate in the CCRO process is a function of the time between brine flushes. Therefore, it is not necessary to use multiple stages of six to eight membrane arrays in pressure vessels to achieve high recovery as is required in traditional RO processes. For example, a high-recovery design can be constructed with just one membrane element. However, in practice, the membrane arrays consist of vessels of four or five elements per vessel. These quantities optimally balance performance and costs (5, 6). Good resistance to fouling and scaling and high recovery operation are important in most brackish water desalination, industrial water purification and water reuse applications. The CCRO process provides new and enhanced means for addressing these challenges. Independently controlled crossflow supplied by a circulation pump efficiently washes the membranes resulting in lower Beta values (concentration polarization) and reduces the effects of scaling and fouling (7–9). As the salinity throughout the sequence cycles from the feedwater salinity to that of the most concentrated brine, biofilm formation and scale precipitation can be disrupted and even reversed. Notably, the sequence time of purging concentrate is much shorter than the
induction time for precipitation of most sparingly soluble salts. This contrasts sharply from the steady-state conditions in traditional RO systems, which maintain nearly constant concentrations throughout their membrane arrays for months or even years. In addition, because recovery can be easily manipulated, the adaptive process can be adjusted if the concentration of scaling salts or other feedwater properties change. Because of these properties, the CCRO process is inherently more reliable than a traditional multistage RO, which has been a key factor in the adoption of the autonomous, data-driven process for mission critical applications. Traditional RO systems are only reliable when operated at lower recovery rates. As an example, a single-stage, 50% recovery RO will typically have less fouling and scaling then a two-stage, 75% recovery RO, which in turn will have less fouling and scaling than a three-stage, 88% recovery RO. However, even end users that are exceedingly sensitive to the reliability of their RO system are not operating at the more reliable 50% recovery, but rather, in the 75% to 88% recovery range. The reason is that while reliability is their primary operational driver, they cannot ignore the efficiency consideration, and operate two- or three-stage RO systems. In
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the Analyst Volume 26 Number 1
What Are Practical Approaches to Improve RO Technology? continued
the CCRO process, this compromise no longer exists; in fact, the higher the recovery, the more significant the concentration variations will get, which in turn provides better immunity to biofouling. In addition, the adaptive nature of the process will keep the system at optimal performance as feed or membrane conditions vary over time, providing a level of reliability and efficiency that cannot be achieved with a traditional RO.
Case Study 1: Increasing Efficiency
As the primary ingredient in beverages is water, beverage industry leaders are making a major push to reduce their water footprint through aggressive sustainability goals. One of the easiest ways to meet these goals is by increasing water-use efficiency within the production facilities. As an example, Coca-Cola, the world’s largest beverage company, has managed to increase its water-use efficiency by 27% from 2004 to 2016, reducing its water-use ratio from 2.70 to 1.96 (10). This means that it requires 1.96 liters (L) of water to make 1.00 L of sellable product. As impressive as these results are, the industry leader is not stopping there, with even more aggressive goals for the future. It should come as no surprise that the company has already installed a half-dozen of the CCRO systems, with more units currently under construction. These systems around the globe operate at recovery rates ranging from 91% to 95%, depending on the quality of their feedwater source and the specific bottling line. This greatly improves the 75% to 85% recovery rates that they were accustomed to with traditional multistage RO systems. The improvement is saving millions of gallons of water annually.
in time, which was the worst-case condition over the course of the year. However, there were many months when the feedwater conductivity or temperature would drop, allowing for higher achievable recovery rates. The opportunity to increase efficiency during these times was dismissed though, as adjustment to the steady-state systems was a manual process, requiring mechanical modifications and coming at the sacrifice of membrane performance. In the CCRO systems, the trigger to purge concentrate is based on a recovery set-point (limited by scaling potential at a defined temperature) and/or a permeate conductivity set-point total dissolved solids (TDS) level. This allows for automatic adjustment, so regardless of feedwater conductivity or temperature, the unit will maximize the recovery relative to the conditions of the feed in real-time while simultaneously ensuring permeate quality. The data-driven process has been a simple solution for the company in reducing water-use ratios without any operator engagement. When it comes to corporate sustainability, the foundation is based on three pillars: social, environmental, and economic, which are more commonly referred to as people, planet, and profits. In addition to conserving our planet’s most precious resource so future generations will continue to have access to fresh water, the financial savings and increased bottom line have made the switch to the autonomous, data-driven process a no brainer. Muhtar Kent (11), chairman of the board and former CEO of the company said it best: “If you aren’t responsibly managing water in your business, you won’t be in business 20 years from now.”
The driving operational metric for the company is ensuring that all quality assurance/quality control (QA/ QC) specifications are met in terms of the product water, while maximizing water recovery rates and system utilization rate. While this seems like a simple request, the majority of the bottling plants see slight or drastic variations in feedwater conductivity and/or temperature. Both of these values will change the achievable recovery, particularly when bottling a sodium-free product with strict permeate quality requirements.
Case Study 2: Sonoran Desert Paper Production
In the past, the traditional multistage RO systems would be designed and operated based on a single point
Over the years, the paper mill had accepted that purification of the groundwater source was never going to be
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The groundwater in the Sonoran Desert is not known for its quality. If anything, it is known for its high salinity and high concentrations of silica. Not only are the salts a problem, but many of the wells draw water with high concentrations of iron and manganese. In the instance of this particular paper mill, the well water not only had metals, but also high levels of biological activity due to the geothermal conditions (105 oF).
the Analyst Volume 26 Number 1
What Are Practical Approaches to Improve RO Technology? continued
an easy task. A significant budget was allocated every year for membrane cleanings (a supervised event) and system maintenance. Ultimately, the performance of the water treatment equipment became the limiting factor in the overall plant production. To secure access to fresh water for the paper-making process, the mill drilled, cased, and developed two groundwater wells and used a treatment train consisting of pressure filtration with greensand media for pretreatment of iron and manganese before entering a multistage traditional RO system. The traditional RO system struggled to perform with the challenging feedwater, requiring three biocides a week and biweekly high- and low-pH cleanings (CIPs). The CIPs were triggered based on a reduction in normalized permeate flow and/or a reduction in differential pressure across the membrane array. Membrane autopsies confirmed the culprit was organic fouling and silica scaling because of the difficultto-treat groundwater.
In 2014, the paper mill decided it was going to double its capacity by installing a second paper-making machine. The expansion not only required more paper-making equipment, but also required a 100% increase in the capacity of purified water. The problem with the traditional RO system was that doubling the capacity meant double the concentrate, which was a limiting factor because of the discharge permit. To minimize the water footprint and concentrate volumes, the paper mill upgraded its traditional multistage RO system to two CCRO systems. Not only did the solution double the required permeate capacity, but the units also did so while reducing the volume of concentrate produced over the single traditional system with half the capacity that the mill operated at before. This was achieved while extending the CIP frequency and significantly reducing the energy and chemical consumption. The results are presented in Table 1.
Membrane Performance
System Performance
Reverse Osmosis Design
Table 1: Multistage RO versus CCRO, long-term performance.
# of Trains # of Stages Array (per train) Process Recovery Utilization Rate Permeate Flux (gfd) Daily Process Water (gallons) Daily Wastewater (gallons) Specific Power Consumption (kWh/kgal) Antiscalant Consumption (ppm) Biocide Frequency CIP Frequency Lead Element Flux (gfd, avg) Flux Distribution (gfd, avg) Max Beta Value Beta Range
Value
Multi‐Stage
Closed Circuit
1 x 100% 2 3:1 (28 Membranes) Steady‐State 73% 90% 15.4
2 x 100% 1 10 (40 Membranes) Dynamic 88% 63% 15.5
155,520 57,521 1.75 8 3X / Week 24X / Year
311,040 42,414 1.67 3 1X / Week 4X / Year
200% 26% 5% 63% 300% 600%
Increase in Permeate Production
20.5 (6.5 ‐ 20.5) 1.14 1.03 ‐ 1.14
18.0 (13.9 ‐ 18.0) 1.09 1.04 ‐ 1.09
12%
Reduction in Lead Element Flux
4%
Reduction in Max Beta Value
Organic and inorganic fouling in a traditional steadystate RO process typically occurs on the lead elements where individual membrane element fluxes are the highest and microorganisms have a stable environment, giving them the ability to flourish. Scaling occurs on the tail elements, where membrane elements are continuously exposed to the highest salinity and individual membrane element fluxes are at their lowest. When it 14
Reduction in Wastewater Generated Reduction in Energy Required Reduction in Antiscalant Use Extension in Biocide Frequency Extention in CIP Frequency
comes to fouling and scaling, higher crossflow velocities always help to reduce concentration polarization (Beta values); however, in a steady-state process where recovery, flux, and crossflow are coupled, this is difficult to achieve unless operators are willing to sacrifice performance elsewhere in the system. In the CCRO process, recovery is achieved in time, the Analyst Volume 26 Number 1
What Are Practical Approaches to Improve RO Technology? continued
versus in space as with traditional RO, so shorter membrane arrays can be used to reduce lead element flux. Salinity cycling and full periodic purging disrupts organic fouling, and crossflow is independently controlled with a circulation pump providing ultimate membrane performance. Antiscalant consumption is also reduced because of reduced concentration polarization and slower induction times associated with silica scale formation.
U.S. Environmental Protection Agency (EPA) have set regulatory limits to the concentrations of nitrates in potable (drinking) water. While the majority of potable water sources fall below these nitrate limits, regions with shallow wells or surface water can be significantly affected when located in agricultural regions where fertilizers are used to increase the yields and quality of harvests. Figure 2: Two CCRO systems.
While not a driving operational metric for brackish or wastewater RO, energy savings is still an expense that needs to be included in the total cost of ownership of an RO asset. In any RO system, the initial pressure required to desalinate the source water is a function of the composition, temperature, flux, and number of membranes in series. In the case of the paper mill, the traditional two-stage RO had 14 membranes in series, and the applied pressure needed to be high enough, even at the 14th membrane. The applied pressure will be higher than the osmotic pressure of the highest salinity concentrate, just before it is rejected from the system. In contrast, the CCRO system has four membranes in its single-stage design. This means the initial pressure of the sequence, when it is filled with fresh feed at the beginning of each batch, is much lower than that of the traditional RO; however, as the system concentrates up salts, the required osmotic pressure rises. Ultimately, the system reaches the same pressure as the traditional RO, or higher in the case of 88% versus 73% recovery, but with all the time spent below the fixed pressure of the traditional RO, the CCRO systems still saved up to 5% in energy.
Case Study 3: Ensuring Children’s Safety
On Nov. 29, 1944, a team of doctors at John Hopkins Hospital performed the first successful surgery to cure Tetralogy of Fallot, more commonly known as “blue baby syndrome” (12). The congenital heart disease in infants can be caused by methemoglobinemia, or a reduced oxygen-carrying capacity of hemoglobin, the iron-containing protein that transports oxygen throughout the body. It is generally accepted within the medical community that high concentrations of nitrates in drinking water can be a co-factor for this disease (13). In an effort to reduce the number of infant-related surgeries, the World Health Organization (WHO) and 16
A Fortune 50 Midwest-based food and beverage company was in the process of expanding one of its production plants when it encountered this exact problem. The corn-processing facility was located in a region with significant agricultural activity and used surface water as makeup water to the plant. Over the course of the year, it would encounter high (20 milligrams per liter [mg/L]) and low (5 mg/L) levels of nitrate (as NO3) with a feedwater temperature ranging from 15 to 25 °C. Normally, this would not be an issue, except that one week out of each month, the plant produces ingredient water used in baby food products, requiring a nitrate limit not to exceed 2 mg/L for the downstream processes. To manage the variable nitrate concentrations, the company installed two CCRO systems to purify this variable feed source (shown in Figure 2). The systems used a custom trigger connected to an online nitrate analyzer to automatically adapt to the seasonal changes in feedwater nitrate concentrations and temperature (temperature effects salt passage in RO membranes and systems). The CCRO systems typically operate at 90% recovery and could be set to operate at much higher recovery rates.
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What Are Practical Approaches to Improve RO Technology? continued
However, when the custom nitrate algorithm is activated, the unit will automatically adapt to the changing feedwater conditions to ensure the nitrate levels in the permeate never exceed the QA/QC specifications for the ingredient water. The systems achieve this by automatically adjusting recovery, dropping down to 82% when the water is the warmest and at the highest concentration of nitrate and maintaining 90% recovery when the water is the coolest and the concentration of nitrate is at its lowest. This is all done with no operator engagement. For a traditional RO, operating at 82% versus 90% recovery would be a challenge that would require expertise and even with it, will generate an imbalance of crossflow and flux without mechanical modifications. This would all require more oversight, expertise, and supervised maintenance activities, such as thottling valves, adding stages, and performing membrane and replacements, all with the respective oversight, labor, downtime, and cost implications. This flexibility has provided the plant with a simple and reliable solution to what was initially a very difficult challenge that could not be achieved with a traditional, multistage RO system.
Figure 3: Containerized CCRO system. The inset photo on the lower right corner provides an interior view of the container with the RO treatment system.
Any potential replacement needed to be extremely reliable with exemplary water recovery rates. Given that many of these peaking power plants are not manned on a daily basis, it was vital that any alternative to the mobile demineralizers be largely autonomous and reliable.
The power generation company identified five gas-fired peaking plants that were looking for reliable and cheaper ways to manage their water needs—Stanton, Norwalk, Ontario, and Rancho Cucamonga in the Los Angeles Basin, with the fifth in Ventura County, Case Study 4: Reducing Power at Oxnard, on the Pacific Coast. The peaking plants Generation Cost needed an alternative to mobile demineralizers that Southern California Edison (SCE) depends on ultrawould allow them to simultaneously reduce their operpure water for emission control and cooling in five of ational expenses and its peaking power improve operational plants. In most of “An RO system made the most sense to replace reliability without these applications, sacrificing water the water is from the expensive demineralization trailers, but quality. municipal sources traditional RO systems always had limited water and must be made recovery rates.” An RO system made into high-purity the most sense to water before use in replace the expensive the power plant. demineralization trailers, but traditional RO systems Until recently, the company had been relying solely on always had limited water recovery rates. This can be rented, mobile demineralization trailers to purify water overcome, in part, by setting up multistage RO systems, for use in these peaking power plants. However, these but the tradeoff is an increase in operational complexity. systems were costly, consumed a lot of water in the Multistage RO systems are also more difficult to mainsupply chain, and presented a singular point of failure in tain with each subsequent stage and require significant the plant. downtime for cleaning and maintenance. The result is that a traditional RO system with more than two or three stages will suffer from reduced reliability. 17
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The company adopted CCRO along with mixed-bed ion exchange polishers to address all its concerns at the five peaking power plants. It estimates a savings of 44 million gallons of water per year through the systems. The RO systems operate at 91% recovery in a simple and flexible single-stage design, producing a guaranteed water purity of <10 microsiemens per centimeter (µS/cm). When compared to a traditional multistage RO system, the CCRO systems provide an additional 18% savings in feedwater consumption and a 64% savings in brine disposal costs.
A pharmaceutical facility in drought-stricken California was urgently trying to find a way to reuse its wastewater, but it encountered a significant challenge because of the variability in the wastewater characteristics. The salinity of the wastewater fluctuated daily, with conductivity values ranging from below 100 µS/cm to more than 2,000 µS/cm, and the COD levels were as high as 2,000 mg/L. Under the guidance of its environmental engineering firm, the company contacted a supplierB to install a treatment train consisting of microfiltration (MF) followed by CCRO. The MF would remove any suspended solids and the RO would remove the salts so that the water can be reused for boiler and cooling tower makeup in addition to irrigation water.
In addition, the plants will greatly improve reliability because of the high-quality permeate and by operating the mixed-bed polishers in series. This novel approach has enabled SCE to reduce its annual water operating The CCRO process system was set up to operate using costs by 85%, from about $1.5 million to $0.225 million three set points: volumetric recovery, internal conducper plant. The tivity, and pressure. CCRO systems The volumetric “In pharmaceutical manufacturing, water is critical, have been successrecovery set point not only for the highly regulated ultrapure process was set at 95%, the fully commissioned at all five plants internal conducwater, but also for boilers and cooling towers.” (see Figure 3). For tivity set point was adopting new techset to 14,800 µS/ nology in the pursuit of sustainability, this project earned cm and the pressure set point was set to 300 pounds the company the prestigious 2017 Power Magazine per square inch (psi). Regardless of the continuously Water Award, which is given to innovative leaders in the changing composition of the wastewater, the unit would power industry (14). adapt in real-time to maximize recovery relative to the continually changing wastewater composition. As you can see from Figure 4, the RO automatically adapts over Case Study 5: Reusing Pharmaceutical the course of a week to drastically changing feedwater Wastewater conditions. To show just how much this wastewater In pharmaceutical manufacturing, water is critical, not varied, you can see the color of the concentrate change only for the highly regulated ultrapure process water, over the course of the week in the far right beaker in but also for boilers and cooling towers. To mitigate risk Figure 5. In more than six months of operation on associated with water scarcity, the industry has taken a the continuously changing wastewater streams with proactive approach to minimizing the water footprint no antiscalant, the system never required a CIP. A with a significant focus on the reuse of high-strength CIP was conducted to set a baseline and show that the organic effluent; however, the reuse of these complex membranes were recoverable. wastewater streams presents significant challenges, from the high total suspended solids (TSS), biological oxygen demand (BOD), and chemical oxygen demand (COD) levels to the daily variations in salinity and its associated wastewater composition, depending on the product mix that is being produced.
18
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What Are Practical Approaches to Improve RO Technology? continued
Figure 4: CCRO performance.
Case Study 6: Reusing Municipal Wastewater
Figure 5: RO concentrate from Case Study 5.
A common theme in the water industry is reusing municipal effluent for industrial applications, including boilers, cooling towers, and process streams. The primary treatment equipment required is MF or ultrafiltration (UF) to remove suspended solids and RO to remove dissolved solids. Ultimately, the limiting factor on the overall plant efficiency becomes the performance of the RO, as the MF or UF must all be designed around the full-flow. Increasing recovery rates beyond 85% on municipal effluent has proved challenging because of the high concentrations of organics in the feedwater. In 2016, Padre Dam Municipal Water District (California) completed a nine-month pilot study to evaluate the performance of CCRO. The goal of the study was to demonstrate the maximum achievable recovery while exceeding a CIP frequency of 30 days. Although a traditional multistage RO was unable to operate at 92.5% recovery for longer than 22 days, the performance for the CCRO is shown in Figure 6 (15). The single-stage system was able to operate at 95% and 96% recovery while exceeding the target CIP frequency of 30 days and was then operated all the way up to 97.5% recovery.
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What Are Practical Approaches to Improve RO Technology? continued
Figure 6: CCRO performance when treating a municipal wastewater.
One of the distinct advantages to the CCRO design is that shorter membrane arrays can be used to achieve any desired recovery rate. Where a traditional threestage RO with seven membranes per pressure vessel would ultimately have 21 membrane elements in series, a CCRO design can achieve 98% recovery with four or five elements in series. The fewer the number of membranes were in series, the lower the lead element flux and the better the flux distribution. This leads to better overall membrane performance and longer membrane life. In addition to the shorter membrane arrays, as recovery is achieved in time in the CCRO design, the pressure at the beginning of the sequence may be 100 psig, and 30 minutes later at the end of the sequence, it is 300 psig. Once the desired recovery rate is achieved, the concentrate is flushed from the system with fresh feedwater. This salinity cycling and continuous purging does not provide a conducive environment for organics to thrive, which differs from the steady-state conditions of multistage RO systems.
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Total organic carbon (TOC) is routinely used in municipal wastewater applications to monitor membrane integrity and performance and was incorporated into the testing at the water district. Per the RO membrane manufacturerâ&#x20AC;&#x2122;s specifications, the maximum feedwater TOC value is 3 mg/L. If higher values are experienced, a loss of flux can be expected, and the effects can be irreversible. Figure 7 (15) shows the feed, concentrate, and permeate TOC values for the CCRO system. Although the feedwater TOC values were approximately 10 times the maximum concentration, as per the membrane manufacturerâ&#x20AC;&#x2122;s specifications, when compared to Figure 6 (15), the loss in specific flux was minimal. In addition, the loss of specific flux was reversible, as even the CIPs with no heat were able to recover the membranes.
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What Are Practical Approaches to Improve RO Technology? continued
Figure 7: Feed, concentrate, and permeate TOC values in CCRO.
These results have been repeated elsewhere in Southern California. The Sanitation Districts of Los Angeles County achieved a sustained recovery of 93% (16), the city of Los Angeles achieved a sustained recovery of 95% (17), Orange County Water District achieved a sustained recovery of 92% and is optimizing to go higher (18), and the Eastern Municipal Water District has purchased a demonstration unit (Eastern Municipal Water District, 2018). San Jose State University is an example of a non-municipal end user that also recently installed a CCRO system to treat tertiary treated wastewater from the San Jose/Santa Clara Water Pollution Control Plant for makeup to their boiler system. The solution will guarantee the university a minimum recovery rate of 93%, with a permeate conductivity of less than 30 µS/cm.
Conclusions
In this article, we have examined an RO technology that addresses all the pain points of multistage RO by using the strengths of simple (dead-end) filtration with the strong points of crossflow filtration. This simple and fundamental change, coupled with a data-driven and autonomous Internet of Things (IoT) software has allowed end users to achieve high water recovery rates of the incoming feedwater without hydraulic limitations. This approach has also shown that fouling and scaling can be limited and that the time between
23
CIP can be extended. The CCRO technology also can prolong membrane life and allows for better management of water quality variations. End users also can save money because of lower use of treatment chemicals and electricity. One important purpose of this article was to provide examples of success stories involving the use of RO technology using the CCRO approach to the technology. In each case study, it was necessary to work around the limitations of RO and find ways to meet the water treatment needs of particular end users in ways that helped to make the technology more reliable and efficient. Future advances in RO technology could include the following: More sophisticated control strategies New membranes Enhanced fluid mixing with complex spacer geometries (20) New modeling techniques New antiscalant chemistries
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What Are Practical Approaches to Improve RO Technology? continued
References
Endnotes
1. Efraty, A. (Dec. 8, 2009). “Apparatus for Continuous Closed-Circuit Desalination under Variable Pressure with a Single Container”, U.S. Patent No. 7,628,921.
A
3. Bratt, R. (March 21, 1989). “Method and Apparatus for Fluid Treatment by Reverse Osmosis”, U.S. Patent No. 4,814,086.
Michael Boyd has been in the water industry for more than 15 years and currently serves as regional director for Desalitech Inc. Mr. Boyd has spent the majority of his career serving the industrial and municipal markets. He holds a B.S. in engineering technology from the University of Central Florida. He may be contacted at mike.boyd@desalitech.com.
The CCRO process mentioned in the text is also known as ReFlex™ RO, which features Closed-Circuit Desalination™. Both are brands of Desalitech Inc.
Desalitech, Newton, MA, is the supplier company mentioned in the text.
2. Efraty, A. (April 13, 2010). “Continuous Closed-Circuit Desalination Apparatus without Containers”, U.S. Patent No. 7,695,614.
B
4. Szucz, L.; Szucs, A. ( Jan. 8, 1991). “Method and Apparatus for Treating Fluids Containing Foreign Materials by Membrane Filter Equipment,” U.S. Patent No. 4,983,301.
5. Stover, R. (November-December 2011). “CCD Starts a New Generation for RO”, Desalination and Water Reuse, pp. 34-35. 6. Stover, R. (September 2012). “Evaluation of Closed-Circuit Reverse Osmosis for Water Reuse”, Proceedings of the 27th Annual Water Reuse Symposium, Hollywood, FL. 7. LewaPlus (2018). Version 1.15.0, LANXESS, Cologne, Germany.
8. Proton Membrane Aqueous Chemistry Calculator (n.d.). American Water Chemicals, Plant City, FL. 9. Dow Water & Process Solutions (2016). “Reverse Osmosis System Analysis”, Version ROSA_Desalitech– 2017, Dow Water & Process Solutions, Edina, MN.
10. The Coca Cola Co. (2016). 2016 Sustainability Report, retrieved from https://www.coca-colacompany.com.
This article is based on a paper presented by the author at the 2018 AWT Annual Conference, which was conducted Sept. 26–29, 2018, in Orlando, Florida.
11. Kent, M. (Sept. 20, 2016). “Our Water Wake-up Call; What Will Be Yours?, [Web log post], retrieved April 19, 2018, from http://www. coca-colacompany.com.
12. Blalock, A.; Taussig, H.B. (May 19, 1945). “The Surgical Treatment of Malformations of the Heart”, Journal of the American Medical Association 128(3), pp. 189-202.
13. Knobeloch, L.; Salna, B.; Hogan, A.; Postle, J.; Anderson, H. (2000). “Blue Babies and Nitrate-Contaminated Well Water”, Environmental Health Perspectives 108(7), pp. 675-678. 14. Paulos. B. (August 2017). “Closed-Circuit Reverse Osmosis System Squeezes Money Savings Out of Water Management”, Power Magazine 161(8), pp. 28-29. 15. Idica, E.Y.; Faulkner, B.W.; Trussell, R.S.; Sen, S. (2017). Maximizing Product Water through Brine Minimization: Innovative Recovery RO Testing, U.S. Department of the Interior— Bureau of Reclamation, Washington, D.C.
16. Mansell, B.; Ackman, P.; Tang, C.-C.; Friess, P. (March 15-17, 2015). “Pilot-Scale Evaluation of the Closed-Circuit Desalination Process for Minimizing RO Concentrate Disposal Volume”, presented at 2015 WateReuse California Annual Conference, Los Angeles, CA. 17. Wang, S. (March 12-16, 2018). “How Much Concentrate Can You Squeeze with Closed-Circuit Desalination and What to Consider”, presented at 2018 Membrane Technology Conference & Exposition, West Palm Beach, FL.
18. Gu, H. (March 25-27, 2018). “Pilot Evaluation of Closed-Circuit Reverse Osmosis for RO Concentrate Treatment”, WaterReuse California Annual Conference, Monterey, CA. 19. Eastern Municipal Water District. (Nov. 1, 2017). “November 1, 2018 Meeting of the Board of Directors”, Contract Approval, Action/Info Item 2965.
20. Tilton, N. (Oct. 15-19, 2017). “Direct Numerical Simulations of Unsteady Mixing and Concentration Polarization in Reverse Osmosis Systems”, 9th Sino-US Joint Conference of Chemical Engineering (SUCE 2017), Beijing, China.
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Part 1: Keys to Successful IX Resin Storage Peter Meyers, ResinTech Inc.
water or if the downstream processes that use the treated Generally, ion exchange (IX) resins may be safely stored water are of critical importance. for two to five years (or longer) without significant chemical or physical deterioration. Numerous exceptions exist, and salt-form resins (neutral pH) store better Dry Resin than hydrogen (H) or hydroxide (OH) forms. Indoor Almost all resins are shipped in their moist water climate-controlled storage in the original shipping swollen forms. Although they may lose significant containers is ideal. Precautions should always be taken amounts of moisture and appear dehydrated, suffito store IX resins in their original undamaged shipping cient water usually remains inside the beads to prevent containers. These should be kept in sheltered, reasonably physical breakage when the resin is rehydrated. While well-ventilated areas, protected from extremes of heat air-dried resin usually will not fracture when rewetted, or cold and from rain or excessive contact with air “Frozen resin should be brought to a warm causes chemical damage other forms of moisture. Following these precauover time and a consearea and allowed to thaw before use.” tions, there is little or no quent increase in leachconcern regarding the ables. Physical damage shelf life of the stored resins. So, with reasonable care, due to rehydration may occur in cases of extreme moisIX resins can be stored for five years or longer without ture loss during storage. For these reasons, resins should any ill effects. remain moist during storage. Resins stored in unlined bulk sacks or fiber drums are far more susceptible to dehydration than resins stored in more robust packaging. Circumstances Affecting Resin
Conditions
Freezing and Thawing During the shipment to and storage in areas where temperatures drop below 0 °C (32 °F), storage precautions should be taken to avoid subjecting IX resins to repeated freezing-thawing conditions. Although a few such cycles are generally harmless, repeated freezing and thawing of IX resins, regardless of the forms in which they are supplied, could physically damage the IX resin by cracking or breaking the resin beads. It takes about 10 freeze-thaw cycles before damage is noticeable, so a single episode of freezing is not a calamity. Frozen resin should be brought to a warm area and allowed to thaw before use. Do not plunge frozen resin into boiling hot water, as this can instantly crack and break beads. Hot Resin Temperatures above 105 °F do not damage most resins chemically, although exceptions exist. Elevated temperatures, however, increase the rate at which organic leachables form in the resin, which can then complicate preconditioning requirements prior to use. Any resin that has been subjected to elevated temperatures during storage should be rinsed to waste before use. If the high temperature exposure was longer than a few days, it is a good idea to have the resin analyzed, just to make sure it has not been damaged, especially if the use is ultrapure 27
Precautions Before Using a Stored Resin
Before using any resin that has been stored for more than a few months, it is a good practice to soak the resin in water for a few hours and then rinse it thoroughly. Soaking allows the IX resins to swell back to their original volume slowly and to release any organic contaminants from the resin structure. Rinsing before use purges the organic contaminants. A four-hour soak is sufficient, although overnight is better if time permits. Rinse volume should be sufficient to rinse out any color throw plus some extra. Ten bed volumes (BVs) (75 gallons per cubic foot) are recommended for most applications, 20 BVs are suggested for resins used in potable or ultrapure water treatment applications. Pro tip: Where onsite rinsing is not possible, either delay shipment until just before use or use a third-party supplier to rinse the resin for you.
Special Requirements for Hydroxide and Sulfite Anion Resin Forms Hydroxide-form strongly basic anion resins undergo a slow decomposition during storage. This reaction is temperature dependent and occurs more rapidly in Type 2 anion resins than in Type 1 anion resins.
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Part I: Keys to Successful IX Resin Storage continued
Sulfite-form strongly basic anion resins, unless stored in a way that prevents exposure to air, gradually convert from the sulfite form to the sulfate form (thus diminishing their ability to remove oxygen from water). The shelf life of these products is limited and is highly dependent on storage conditions. Consequently, no exact shelf life can be stated. Sulfite-form anion resin and hydroxide-form Type 2 anion resins older than three months and hydroxide-form Type 1 anion resins older than 12 months, unless stored in gas barrier packaging, should be tested prior to use to verify they remain usable.
Resin Shelf Life Shelf life relates to the resin type, ionic form, storage conditions, and customer expectations for use. For instance, potable water resins that develop an odor or taste during storage are often no longer suitable for use without extensive reprocessing, even though their chemical and physical characteristics are still â&#x20AC;&#x153;like new.â&#x20AC;? For regenerated resins and resins used in ultrapure applications, packaging in gas barrier liners can greatly extend usable life. Table 1 provides a guideline for the acceptable length of resin storage. Table 1: Guideline on acceptable resin storage length. Storage method
Outdoor, covered with tarp
Indoor, not temperature controlled
Indoor and climate controlled
Climate controlled in gas barrier packaging
Na form SAC
1 to 2 years
2 to 5 years
5 to 10 years
> 10 years
Cl form SBA
1 to 2 years
2 to 5 years
5 to 10 years
> 10 years
H form SAC
1 to 2 years
2 to 5 years
5 to 10 years
> 10 years
OH form type I SBA
1 year
1 to 2 years
2 to 5 years
> 5 years
OH form type II SBA
NR*
0.25 years
0.5 years
1 to 2 years
H or Na form WAC
1 to 2 years
2 to 5 years
5 to 10 years
> 10 years
WBA any kind
1 to 2 years
2 to 5 years
5 to 10 years
> 10 years
Chelating resins
1 to 2 years
2 to 5 years
5 to 10 years
> 10 years
Mixed Bed
1 year
1 to 2 years
2 to 5 years
> 5 years
Ultrapure mixed bed
NR
1 year
1 to 2 years
2 to 5 years
Sulfite form SBA
NR
0.1 year
0.5 years
1 year
Cl form Acrylic SBA
NR
1 year
2 to 5 years
> 5 years
OH form Acrylic SBA
NR
0.5 years
Year
>1 year
Table Notes: NR = Not Recommended SAC = Strongly acidic cation resin SBA = Strongly basic anion resin WAC = Weakly acidic cation resin WBA = Weakly basic anion resin
Regenerated resins deteriorate more rapidly in air than when protected from gas transfer. Hydroxide form anion resins absorb carbon dioxide (CO2) from air and become exhausted. All resins develop leachables over time that may make them unusable for some applications or require reprocessing prior to use.
Changes as Resin Ages
Aside from possible dehydration and freeze damage, several other changes occur as resin ages. Mostly, these changes have to do with leachable formation and loss of functional groups. SAC resins gradually desulfonate, releasing sulfuric acid and aromatic sulfonic acids that separate from the polymer backbone. These acids remain trapped in the resin beads until the beads meet water, and then are released. SBA resins release amines rather than acids. Anion degradation is somewhat faster than cation breakdown, particularly for anion resins in the hydroxide form. Since amines are somewhat volatile, older anion resins that have been 28
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Part I: Keys to Successful IX Resin Storage continued
kept in sealed containers (especially if stored in the hydroxide form) can release amines to the air well above Occupational Health and Safety Administration (OHSA) guidelines. Mixed beds are â&#x20AC;&#x153;self-neutralizing.â&#x20AC;? The cationic leachables are absorbed by the anion component, and the anionic leachables are absorbed by the cation component. Both components gradually exhaust the mixed resin, lowering the amount of regenerated capacity remaining. All resins (except those stored in inert gas) gradually decompose, their plastic structure slowly weakening from exposure to oxygen. Degraded resins release bits and pieces of lower molecular weight (mwt) polymer as well as oxidative byproducts. (Note: Molecular weight is the sum of the atomic weights of all the atoms in a molecule.) Leachables build up over time, requiring longer and more extensive rinses and possibly regeneration to purge them before use. Many cationic leachables foul anion resin and anionic leachables foul cation resin. Resins used in series that are not fully rinsed are therefore susceptible to fouling related to storage. Over very long periods of time, drum liners, and even drums and bulk sacks themselves, begin to deteriorate. Packaging older than 10 years is at risk of shedding into the resin. For this reason, 10 years is generally considered the outer limit for resin storage, except under ideal storage conditions.
Storage of Used Resin Outside the Vessel If the resins are to be removed from the IX vessels for long-term storage, it is best if they are first fully exhausted or converted to their neutral salt form, drained of excess water, and placed in watertight containers, such as plastic drums with liners and locking ring seals, like those used for shipping new resin. Steel drums are not recommended because of the risk that the resin will corrode the steel and then be contaminated by the rust. Fiber drums are not recommended because even a tiny hole will allow water to wet and weaken the fiber. For strong cation resin and strong anion resins, storage in the sodium and chloride forms is best, but 29
almost any pH-neutral salt form is acceptable. Although resins can be stored in the hydrogen and hydroxide forms, shelf life is limited and handling a bit more difficult. When storing used resins outside the vessel, follow the same general guidelines for storage of new resins.
Inside the Vessel Unless the IX system is going to be shut down for more than a few weeks, the best practice is simply to leave the vessels filled with water, with all valves to and from the unit turned off. If the system will be shut down for more than a few weeks, some form of storage preparation is recommended. Depending on the nature of the system, the following suggestions are offered for successful resin storage: Softeners and salt-regenerated anion units. Rinse monthly with a minimum of one vessel volume clean feedwater. For units in series (such as a softener followed by a chloride cycle dealkalizer), rinse the lead unit to waste first, then use the effluent to rinse the second unit. Regenerate each unit before returning to service. Separate-bed demineralizers (and other H- and OH-form units). Cation and anion resins can be left in the regenerated (H and OH) forms and rinsed at two- to four-week intervals in the following manner: 1. Rinse one vessel volume of raw water through the first vessel (usually the cation) to waste. 2. Using the effluent from the first vessel, rinse a vessel volume through the second vessel (usually the anion) to waste. 3. Continue with any other vessels in series, first rinsing the preceding vessels to waste and then thoroughly checking out of each downstream vessel in turn. 4. Regenerate each unit before returning to service.
Warning: Cation Leachables Foul Anion Resin As time passes with no water flowing, leachable organic material will form in the cation resin. These leachables irreversibly foul anion resins. Rinsing the cation resin to the Analyst Volume 26 Number 1
Part I: Keys to Successful IX Resin Storage continued
waste first removes these organics and prevents fouling of the anion resin.
Mixed Beds The cation and anion resins should be separated by backwashing before storage so that the cation and anion layers can be rinsed individually. A simultaneous rinse of both resin types (up through the cation resin and down through the anion resin, with both rinses exiting through the interface collector) at approximately one-month intervals will help ensure the resin remains unfouled during storage. Before a return to service, the resins should be regenerated, remixed, and rinsed.
form, typically the sodium form for SAC resins and the chloride form for SBA resins. The weak acid and weak base resins are most stable in their regenerated forms, hydrogen form for WAC resins and free base form for WBA resins. It is beyond the scope of this article to provide detailed instructions for exhausting or regenerating resin. However, as a general guideline, avoid sudden changes in pH or in concentration. When exhausting with salt, keep the concentration below 1%. If in doubt, consult knowledgeable sources before proceeding.
Freeze Protection During Storage Polishing Demineralizers Cold temperatures do not damage resin chemically; the risk is physical cracking and breakage of the resin beads. When polishing mixed beds or other polishing deminMany climates are moderate enough to not freeze the eralizers are used in high-purity water (also known as water in a vessel. However, if freezing is possible, the ultrapure water) applications, the decision must be made water in the vessel should be drained as a precaution. whether it is worth the extra work to re-purify the resins Otherwise, the expansion for reuse. This must be “Cold temperatures do not damage resin as water freezes could compared with the additional degradation that chemically; the risk is physical cracking and damage the internals or even the vessel itself. will otherwise happen breakage of the resin beads.” if the resins are not converted to stable salt If freezing is likely, a forms prior to shut down and storage. simple remedy is to drain the water and refill with salt brine. A 10% sodium chloride solution offers protection down to approximately 20 °F (-6 °C). Saturated calcium For ultrapure water applications it is probably best to chloride offers protection down to approximately -40 °F leave the resins in their highly regenerated forms and (-40 °C). Sodium chloride is less risky to use; use of simply rinse them periodically to keep leachables to a calcium chloride requires any anion resin to be careminimum. Polishing mixed beds have been stored for fully neutralized so that any hydroxide form capacity is more than a year this way and still rinsed up well when removed from the resin. returned to service. Each case should be taken on a specific basis. Following storage in salt solutions, the brine should be slowly rinsed out with water so that the osmotic swelling It is important to keep all valves to and from the deminthat occurs as the resin rehydrates is spread out over eralizer vessels in the “off” position so that resins remain time. A minimum of one hour is recommended for the submerged in water, thus minimizing contact with first vessel volume of water, and then any additional oxygen and microbe-containing air. rinsing can be at any convenient flowrate. Very Long Storage After the salt is rinsed out, the resin should be allowed to For very long-term storage in the vessel, it is best to store soak in water for a few hours prior to being regenerated. the resins in their most stable ionic forms. This retards The soak time allows salt that has diffused into the beads the buildup of leachable organic matter, minimizes to come back out. Finally, be sure to rinse to less than oxidation degradation of the sulfonic acid or amine 5 parts per million (ppm) hardness before regenerating groups, and prolongs the functional life of the resin. anion units with sodium hydroxide, otherwise hardness fouling is likely. For SAC and SBA resins, the most stable form is the salt 30
the Analyst Volume 26 Number 1
Part I: Keys to Successful IX Resin Storage continued
Although organic solvents such as alcohols and glycols can be used to prevent freezing, their use is rather problematic. For one, disposal of the spent solution is a problem. For another, it takes extensive rinsing to remove all the solvent. Lastly, most glycols contain additives that can foul resin. All in all, salt brine is better.
Where resin use is critical to downstream processes and has been stored for a long time, it is advisable to pull samples a month or two before return to service. These resins should be analyzed to ensure that the resin remains suitable for use.
Preventing Biogrowth During Storage Several strategies, including sterilization techniques, can be used to prevent biogrowth during storage. Brine may be used to retard biogrowths. In this case, the resin beds are deliberately left in a brine solution, like that used for freeze protection. Instead of rinsing the brine out after exhausting the resins, additional brine can be introduced such that the brine concentration is approximately 5% and left in the brine until the resins are ready to be used again.
Some older storage instructions suggest storage in glycol, alcohol, or in various sterilizing solutions. In the author’s opinion, these practices do not make sense. At best, it takes so much water to purge and dispose of the chemicals from the resin after storage that the cost exceeds that of new resin. At worst, the chemicals foul the resin and are potentially washed into downstream processes where they create additional problems. Table 2 provides a list of guidelines to aid the successful storage of new and used IX resin storage.
Prior to use, the brine must be thoroughly rinsed out of the units (each separately). Then the resin must be super regenerated to restore it to its fully regenerated form, charged and ready to use. Other strategies for controlling biogrowths include storing the resin in an inert nitrogen atmosphere and using various chemical biocides. Oxidizing biocides are a bad bet; they damage the resin and are used up over time. Many nonoxidizing biocides damage IX resin or are not compatible with downstream processes. Various alcohols can be used without risk to the resin but are time consuming to rinse out and may be problematic to dispose of. All in all, brine is likely as good an alternative as any.
Closing Thoughts on Resin Storage
Table 2: Guidelines for successful IX resin storage. • Store in original undamaged shipping containers • Store in a well-ventilated storage area • Protect from extremes of heat or cold (above freezing, below 105 °F) • Protect from rain, sun, and other weather extremes
Figures 1 and 2 show examples of IX resins that could be stored. Figure 1: Macroporous resin.
In any event, storing resin in a way that retards biogrowths does not guarantee sterility. Sterilization procedures may still be needed before return to service.
Precautions Before Using Stored Resin Always rinse resins before returning them to service. Regeneration is advisable, even if the resin was stored in the regenerated form. For IX units in series (such as softeners followed by dealkalizers, or hydrogen-form cation units followed by hydroxide-form anion units), rinse the first unit thoroughly before using the effluent to rinse the second unit. Pre-rinsing removes leachables that could otherwise foul the downstream exchangers. 32
the Analyst Volume 26 Number 1
Part I: Keys to Successful IX Resin Storage continued
Peter Meyers is the technical director for ResinTech Inc., an ion exchange resin manufacturer. Mr. Meyers has more than 45 years of experience covering a wide range of ion exchange applications, from demineralizers, polishers, and softeners to industrial process design and operation. Mr. Meyers is co-inventor along with Mike Gottlieb of a hybrid ion exchanger used to remove arsenic from potable water. He can be reached at pmeyers@resintech. com.
Figure 2: Sulfonated resin.
This article is based on a paper presented by the author at the 2018 AWT Annual Conference, which was conducted Sept. 26–29, 2018, in Orlando, Florida.
Closure
This discussion about the storage of ion exchange resins is the first part of this article series that describes the physical aspects of how resins are used. Other parts of the series include an introduction to using ion exchange resins; moving resins from place to place; and loading, unloading, disposal, and step-by-step procedure outlines.
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the Analyst Volume 26 Number 1
Can Hydrophobic Modifications to Polymers Achieve Better Carbonate Scale Control? Klin Rodrigues, Ph.D., and Jan Sanders, Nouryon (formerly AkzoNobel)
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Abstract
It is a known fact that nonionic modifications of polymers improve scale control performance. These nonionic modifications can be hydrophilic or hydrophobic. The role of hydrophobic modifications of polymers for carbonate scale control has not yet been widely studied. This article will investigate the impact of hydrophobic substitutions of polymers for carbonate scale control in cooling water systems.
Background
Polymers (1) are long chains of molecules. If we examine the meaning of the word “polymer,” “poly” refers to the idea of “many”, and “mer” refers to “repetition.” Therefore, a literal meaning would refer to “many units of monomers” in the context of water treatment. Polymers are widely used in the water treatment industry to minimize scale formation. A wide array of water treatment formulations will also contain phosphate to minimize corrosion. Due to phosphate bans in a number of states, it is becoming increasingly common to operate cooling systems in the higher pH ranges to minimize corrosion issues. Higher pH leads to increased calcium carbonate scaling. Therefore, it is becoming important to have polymers with better calcium carbonate scale control properties. In cooling water systems, calcium carbonate is one of the most common scales. Calcium carbonate scale in most treatment applications is formed by a series of chemical reactions that are shown in Reactions 1 through 4. CO2(g) CO2(1)
Reaction 1
CO2(l) + H 2O HCO3- + H+ Reaction 2 HCO3- CO3-2 + H+ Reaction 3 Ca+2 + CO3-2 CaCO3
Reaction 4
35
Polymers minimize scaling in water treatment systems through a combination of three mechanisms: 1. Threshold inhibition: This is the ability of the polymer to suppress scale formation. Unlike other additives, polymers do this at sub-stoichiometric levels. 2. Crystal growth modification: Polymeric additives are known to modify the growing crystal structures. The extent of crystal growth modification primarily depends on the functionality in the polymer and to a lesser extent, the polymer’s molecular weight (2, 3). 3. Dispersion: Most anionic polymers used in water treatment applications have the potential to be good dispersants, but their ability to disperse solids is primarily determined by molecular weight. Lowmolecular weight polymers like polymaleics are poor dispersants. Similarly, high-molecular weight polymers tend to have poor dispersancy properties. In general, polymers with a weight average molecular weight of 3,000 to 7,000 Daltons tend to have the best dispersancy properties. A number of anionic polymers are used in water treatment. Polymaleics (PMAs) (4, 5) are widely used in water treatment applications for calcium carbonate scale control. There are a number of variations of polymaleic acid (PMA). The performance of these polymers is dependent on the process used to produce them, whether by aqueous or solvent-based processes. For purposes of this article, a polymaleic produced in an aqueous system will be designated as PMA-AQ , and a polymaleic produced in a solvent system will be designated as PMA-S. The 13C 1D nuclear magnetic resonance (NMR) spectrum of PMA-AQ is shown in Figure 1.
the Analyst Volume 26 Number 1
Can Hydrophobic Modifications to Polymers Achieve Better Carbonate Scale Control? continued
Figure 1: 13C 1D NMR spectra of PMA-AQ.
This spectrum appears to be consistent with the structure of PMA-AQ , as currently understood (see Figure 2). The structure has hydroxyl (OH) end groups, which are a result of the initiating system typically used in these products. Figure 2: Proposed structure of aqueous polymaleic/PMA.
The commonly accepted structure above does not have any CH 2 groups; however, 13C 1D DEPT NMR spectrum (Figure 3) for the PMA-AQ indicates the presence of a significant fraction of CH 2 groups. (In 13C 1D DEPT spectra, the C=O [carbonyl groups] are not present, the CH and CH3 groups are above the axis, and the CH 2 groups are below the axis.) Figure 3: 13C 1D DEPT NMR spectra of PMA-AQ.
A possible explanation for this is that significant portions (one-third) of the acid groups are decarboxylated. Maleic acid (HO2CCH=CHCO2H) is hard to polymerize and requires strenuous polymerization reaction conditions, like strong initiator systems and relatively high temperatures. This results in the formation of the maleic oligomer but also in a large amount of decarboxylation. This essentially introduces a hydrophobic methylene (CH 2) group into the polymer. Therefore, a more accurate depiction of the aqueous-based PMA is depicted in Figure 4. Figure 4: Structure of aqueous PMA with decarboxylation.
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Can Hydrophobic Modifications to Polymers Achieve Better Carbonate Scale Control? continued
Solvent-Based Polymaleic Acid
Solvent-based polymaleic acid (PMA-S) is usually polymerized in an aromatic solvent such as xylene. The molecular weight data summarized in Table 1 indicate that PMA-S and PMA-AQ are about the same molecular weight. The residual maleic content for PMA-AQ is typically much lower than that of PMA-S (see last column in Table 1). This is most likely due to the initiating system in the solvent process not being as effective as the one used in the aqueous process. Table 1: GPC data for PMA-S and PMA-AQ. Mw (weight average molecular weight)
Mn (number average molecular weight)
(polydispersity)
PMA-S
639
502
1.3
24,000 ppm
PMA-AQ
637
531
1.2
10,900 ppm
Sample
PD
Residual unreacted Maleic acid
However, the GPC chromatograms for these products look completely different, as depicted in Figure 5. Figure 5: GPC chromatograms for PMA-AQ (solid) and PMA-S (dotted).
The PMA-S appears to have a bimodal distribution, and its chromatogram is not similar to that of the PMA-AQ. These chromatograms clearly show a difference between solvent-based PMAs and aqueous PMAs. To further investigate the structure of the PMA-S, 13C NMR spectra were obtained.
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the Analyst Volume 26 Number 1
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Can Hydrophobic Modifications to Polymers Achieve Better Carbonate Scale Control? continued
The NMR spectrum of PMA-S in Figure 6 shows an aromatic functionality (125 to 145 ppm) incorporated into the polymer. One will note that this aromatic functionality is not present in the spectrum for PMA-AQ (Figure 1). This incorporation of aromatic functionality is likely because of chain transfer to the solvent used in the polymerization, which is typically xylene. NMR analyses further Figure 6: 13C NMR spectrum for PMA-S.
indicate that the amount of maleic acid to xylene functionality is approximately 3:1. An approximate structure of the solvent-based PMA-S is shown in Figure 7. In general, PMA-S is known in industry to be superior in performance to PMA-AQ for calcium carbonate scale control. This is attributed to the crystal-growth modification properties of PMA-S.
Figure 7: Likely structure of PMA-S.
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Can Hydrophobic Modifications to Polymers Achieve Better Carbonate Scale Control? continued
Minimizing carbonate scale requires the polymer to be a good crystal growth modifier and also to have good threshold inhibition and dispersancy. PMAs do not show good dispersancy properties, primarily because of their low molecular weights. The molecular weight can be increased by adding co-monomers to maleic acid. If portions of the co-monomers are hydrophobic (6), this should improve the crystal growth modification. If the molecular weight of these hydrophobic copolymers are carefully controlled, the threshold inhibition and dispersancy properties should improve.
As mentioned earlier, polymers minimize scaling in water treatment systems through a combination of three mechanisms: threshold inhibition, crystal growth modification, and dispersion.
The polymer scientist can choose from a variety of monomers that can hydrophobically modify water-soluble polymers. Some of these monomers are styrene, methyl methacrylate, t-butyl acrylamide, and vinyl acetate. An experimental design was conducted to optimize performance for carbonate scale control by incorporating a series of hydrophobic monomers. The factors in the experimental design included the type of hydrophobic monomer, its molar amount in the copolymer, and molecular weight of the copolymer.
Table 3: Calcium carbonate static test conditions.
The experiments below compare one of the hydrophobically modified copolymers (HMC) from this experimental design with the PMA materials. To compare performance against PMAs, only one polymer from the experimental design was chosen. The study compared the structural characteristics, threshold inhibition, crystal growth modification, and dispersancy, as well as scale control under dynamic conditions, of the PMA-AQ , PMA-S, and HMC polymers.
The resulting data for HMC, PMA-S, and PMA-AQ are plotted in Figure 8. In this test, a minimum of 90% carbonate inhibition is considered acceptable. The amount of polymer required to deliver 90% carbonate inhibition in this test can be regarded as the minimum inhibitor concentration. The minimum inhibitor concentrations for HMC, PMA-S, and PMA-AQ are 4, 8, and 12 mg/L, respectively. These data indicate that the solvent-based polymaleic (PMA-S) is superior to the aqueous-based polymaleic (PMA-AQ ) by almost a factor of two. However, the hydrophobically modified copolymer HMC is superior to the PMA-S by a factor of two and the PMA-AQ by a factor of three.
The molecular weights for the three polymers are listed in Table 2. Table 2: GPC molecular weight data and residual monomer levels for PMA-AQ, PMA-S and HMC. PMA-AQ
PMA-S
648
639
3,666
Mn (number average molecular weight)
534
502
2,305
1.2
1.3
1.6
10,900
25,000
< 500
Residual monomer (ppm)
The calcium carbonate threshold inhibition for HMC, PMA-S, and PMA-AQ was measured under the static conditions listed in Table 3. Note that the test readings are in milligrams per liter (mg/L).
Static Conditions Ca
300 mg/L as CaCO3 (120 mg/L as Ca)
Mg
147.6 mg/L Mg as CaCO3 (36 mg/L as Mg)
Li
8.64 mg/L Li as CaCO3 (1.2 mg/L as Li)
Bicarbonate
350 mg/L as CaCO3 (427 mg/L as HCO3-)
Carbonate
80 mg/L as CaCO3 (48 mg/L as CO3-2)
pH
8.7-8.9
Temperature
50 °C
Time elapsed
17 hours
HMC
Mw (weight average molecular weight)
PD (polydispersity)
Threshold Inhibition Performance Comparison
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Can Hydrophobic Modifications to Polymers Achieve Better Carbonate Scale Control? continued
Figure 8: Calcium carbonate inhibition data for HMC, PMA-S, and PMA-AQ.
Crystal growth modification The crystal growth modification of various polymers was measured using the procedure detailed in a 2014 AWT paper by Standish (7). In the experiments, 50 mL of a solution containing 1,200 mg/L of calcium/Ca+2 (from calcium chloride dihydrate) and polymer was mixed with a solution of 50 mL of 1,200 mg/L of carbonate/CO3-2 (from sodium carbonate monohydrate). The resulting solutions were in the pH range of 9.5 to 10.2 and contain 600 mg/L of Ca+2, 600 mg/L CO3-2, and 30 mg/L polymer. The solutions were heated in a water bath for 18 hours at 70 °C and then allowed to cool. The crystals were collected and photographed by a Scanning Electron Microscope (SEM). Figure 9 shows the resulting images. Figure 9: Crystal growth modification image of (from left to right) no polymer, PMA-AQ, PMA-S, and HMC.
These images (all taken at the same magnification) clearly indicate that the crystal growth modification or distortion properties of the HMC are superior to that of PMA-S, which in turn is superior to that of PMA-AQ. The PMA-AQ appears to round out the calcium carbonate crystals. The PMA-S appears to not only round out the crystals but also create dimple like structures. The HMC completely distorts the crystal structure, giving it a cauliflower like shape, making it difficult to build on itself, and therefore adhere to surfaces. The HMC polymer modifies the crystal substantially, transforming the crystals from calcite to something closer to the vaterite form. This is consistent with the results of GuiCal, et al. (8), where they reported that the better threshold inhibitors produce a larger fraction of the crystals being vaterite rather than calcite.
Dispersancy The third performance vector of a good calcium carbonate scale inhibitor is the ability to disperse scale (or dirt) after the scale has precipitated. Polymers can keep scale or dirt dispersed in the aqueous phase so that they do not adhere 44
the Analyst Volume 26 Number 1
Can Hydrophobic Modifications to Polymers Achieve Better Carbonate Scale Control? continued
to heat transfer surfaces in the system. The dispersancy properties of a series of polymers were measured using the following test conditions: • • • •
Kaolin clay: 2% weight Polymer dosage: 10 mg/L Settling times: 17 hours Temperature: 21 °C
Typically, polymaleic polymers do not have the ability to successfully disperse existing scale because of their relatively low molecular weight. However, the weight average molecular weight (Mw) of the HMC has been optimized to be in the range 3,000 to 7,000 Daltons, which maximizes its dispersancy performance. In Figure 10, the dispersancy properties of a blank (no polymer), HMC, PMA-AQ , and PMA-S are shown. It is obvious from the settling of the clay in the solution that the HMC is a much better dispersant than either of the PMA materials, which show similar performance to the blank (no polymer). Figure 10: Clay dispersancy (from left to right) of a blank (no polymer), HMC, PMA-AQ, and PMA-S.
Comparison in Dynamic Testing
Dynamic testing was used to verify the data seen in the testing above. This dynamic test is designed to simulate performance when applied in a cooling tower or similar system. Dynamic performance tests were conducted on a non-evaporative dynamic test unit, as shown in the schematic drawing in Figure 11. The system design allows increasing cycles of concentration (CoC) by continuous addition of makeup water concentrate and controlled feeding of polymer, with an overflow to maintain constant system volume and constant polymer concentration throughout the test. The water in the system (approximately 20 liters [L]) is contained in a 25-L basin and is circulated through the system through a heat exchange rack. The heated area consists of three heat exchange rods running at approximately 750 watts surrounded by glass tubing for the water to flow through. The heated area of each rod is approximately 23.8 square inches. This results in a heat transfer rate of approximately 16,000 British thermal units per hour per square foot (BTU/hr/ft 2). The water then passes through a corrosion rack (made of 1-inch chlorinated polyvinyl chloride [CPVC] piping), a condenser, and back into the basin. The basin water temperature is controlled through a chiller, which passes cooled water through the condenser. The pH is controlled with a pH controller and a sulfuric acid feed. A flow meter is mounted into the system for monitoring the flow rate of the water through the system. The CoC are controlled and increased through the constant feeding of hardness solutions and concentrated alkalinity solutions. A polymer treatment feed is also added to maintain the desired dosage levels of treatment within the system. The flow across the heat exchangers was kept constant at 3.0 gallons per minute (gpm). Specific conductivity is approximately 750 micro-mhos.
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the Analyst Volume 26 Number 1
Can Hydrophobic Modifications to Polymers Achieve Better Carbonate Scale Control? continued
Figure 11: Schematic of dynamic test unit.
The conditions for dynamic testing are detailed in Table 4. Table 4: Dynamic unit test conditions per cycle of concentration. Parameter
Dynamic Test Conditions
Ca
100.0 mg/L Ca as CaCO3 (40 mg/L as Ca)
Li
2.88 mg/L Li as CaCO3 (0.4 mg/L as Li)
Mg Bicarbonate
49.2 mg/L Mg as CaCO3 (12 mg/L as Mg) 74 mg/L as CaCO (90 mg/L as HCO -)
Carbonate
447 mg/L as CaCO3 (268 mg/L as CO3-2)
Fe
0.5 mg/L
pH
8.80-8.90
Temperature
43-44 °C
Polymer concentration (active)
10 mg/L
3
can be measured. From Figure 12, it can be seen that the HMC stays above 90% inhibition for approximately one cycle of concentration longer than both PMA products. Both PMA products drop rapidly from 100% inhibition to 20% inhibition. However, the HMC drops at a much slower rate, which gives the operator room for error, should the polymer level drop below the minimum inhibitor concentration. These data validate earlier findings that the hydrophobically modified copolymer has superior threshold inhibition, crystal growth modification, and dispersancy, since all three of these factors are accounted for in the dynamic test.
3
Sampling from the basin allows quantification of the ion levels in the circulating water, giving an indication of the polymerâ&#x20AC;&#x2122;s threshold inhibition capabilities. The change in these concentrations over time demonstrates how long the polymer can completely inhibit scale formation. In addition, the rate of decrease in threshold inhibition when the threshold inhibition starts to drop below 90% 46
the Analyst Volume 26 Number 1
Can Hydrophobic Modifications to Polymers Achieve Better Carbonate Scale Control? continued
Figure 12: Calcium carbonate inhibition versus CoC from the dynamic test unit for PMA-AQ, PMA-S, and HMC.
Figure 13: Calcium carbonate inhibition versus calculated LSI from the dynamic test unit for PMA-AQ, PMA-S, and HMC.
The Langelier Saturation Index (LSI) is a measure of the scaling tendency of calcium carbonate to precipitate out and form scale in the system. An LSI of 2 or greater indicates that the system is highly scaling. The dynamic conditions stated in Table 4 were used to calculate the LSI (9). This can be seen in Equation 1.
Images of the dynamic test containing 10 mg/L each of PMA-AQ , PMA-S, and HMC at 5.5 CoC (calculated LSI of 3.6, Fe 2.5 parts per million [ppm]) are displayed in Figure 14. At this point in the testing, all three polymers have less than 10% threshold inhibition. This implies that any carbonate scale control is because of a combination of crystal growth modification and dispersancy mechanisms. The images clearly show that the metallic heat transfer surfaces in the PMA-AQ system are completely covered in scale, while in the PMA-S system, most, but not all surfaces are covered in scale.
LSI = pH – pHs
Eq. 1
Where: pH and pHs = the bulk water pH and the pH at saturation (pHs) The pH at saturation can be calculated using the Equation 2. pHs = A + B – log10 [Ca+2] – log10[Total Alkalinity] Eq. 2 Where: A and B are constants related to temperature and dissolved solids content of the water (see Table A.1 and Table A.2 in appendix of Reference 10). [Ca+2] = the total calcium as CaCO3 in mg/L [Total Alkalinity] = the total alkalinity or M alkalinity as CaCO3 in mg/L The LSI values for data points in Figure 12 were calculated using Equations 1 and 2. The carbonate inhibition data are re-plotted in Figure 13 versus LSI rather than CoC. The data indicate that both PMA-AQ and PMA-S tend to drop below 90% inhibition at a calculated LSI of approximately 2.8. In contrast, HMC tends to fall below 90% inhibition at a calculated LSI of approximately 3.3.
47
This indicates that the PMA-S system is a better crystal growth modifier than the PMA-AQ system since neither polymer is an effective dispersant. In contrast, the metallic heat transfer surfaces in the HMC system are completely free of scale except for in the low-flow zones at the end of each tube. This can be attributed to the superior crystal growth modification and dispersancy properties of HMC. Therefore, under dynamic conditions that simulate an evaporative cooling system, HMC is far superior to PMA-AQ or PMA-S for calcium carbonate scale control. The performance of most polymers is negatively affected by the presence of even 0.5 to 1 ppm of iron (Fe). At 5.5 CoC, the system had 2.75 ppm Fe. The performance of the HMC at a LSI of 3.5 (greater than 3,000 times the carbonate saturation limit) and in the presence of up to 2.75 ppm Fe was extraordinary and remarkable.
the Analyst Volume 26 Number 1
Can Hydrophobic Modifications to Polymers Achieve Better Carbonate Scale Control? continued
Figure 14: Scale buildup of PMA-AQ (left), PMA-S (middle), and HMC (right) at 5.5 CoC (LSI 3.6) under dynamic testing conditions.
Stability With Oxidizing Biocides
To keep microbiological growth from occurring, water treaters typically add mg/L levels of halogens into their water treatment program. Unfortunately, these halogens can have adverse effects on the polymer-scale control performance. To ensure that the performance of the HMC, PMA-AQ , and PMA-S are not altered by the addition of halogens, a static test was completed with the presence of 1 mg/L chlorine. Our experiments (data not shown) indicate that the addition of 1 mg/L of chlorine did not adversely affect the threshold inhibition performance of these polymers.
Formulations A typical water treatment formulation will contain a blend of polymers. Traditionally, formulations contain a polymer to mitigate phosphate scale and a polymer such as polymaleic to minimize carbonate scale. The polymer used for phosphate scale also delivers dispersancy performance. As phosphates are being regulated out, new formulations do not need to contain a polymer to mitigate phosphate scale. Thus, a hydrophobically modified copolymer that is superior to PMAs for carbonate scale but also gives dispersancy performance will simplify the formulation. Furthermore, by using a single hydrophobically modified copolymer to replace the traditional polymer blends mentioned above, the formulator can maximize performance while minimizing costs.
Conclusions
NMR data indicate that the aqueous-based polymaleic materials have substantial amounts of decarboxylation. This results in the introduction of methylene units,
48
rendering the polymer more hydrophobic than previously thought. Solvent-based polymaleic materials are even more hydrophobic because of the incorporation of an aromatic group into the polymer. It is postulated that this increase in hydrophobicity results in better threshold inhibition and crystal growth modification. Using these observations, hydrophobically modified copolymers were designed and synthesized, and their scale inhibition performance was evaluated. Hydrophobically modified copolymers are designed to have higher molecular weight and much lower residual monomer levels than the polymaleics. The superior performance of hydrophobically modified copolymers over the polymaleic materials has been demonstrated for carbonate scale control, including threshold inhibition, crystal growth modification and dispersancy. The hydrophobically modified copolymers are stable in the presence of oxidizing biocides. They also can control carbonate scale deposition up to a calculated LSI of 3.5 or higher. Hydrophobically modified copolymers allow water treaters to have superior performance and lower formulation costs.
Acknowledgments
The authors would like to thank the following individuals for their contributions to this article: Dr. Eric Twum and Dr. Tom Pagano for the NMR data; Mr. Frank Cambria for the SEM pictures; Mr. Brant Richmond for the applications testing; Mr. Matthew Vanderhoof for details on calcium carbonate crystal structures; and Mr. Dan Ghere for the GPC data.
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Can Hydrophobic Modifications to Polymers Achieve Better Carbonate Scale Control? continued
References 1. Young, R.; Lovell, P. (2011). Introduction to Polymers, 3rd ed., CRC Press, Boca Raton, FL, Chapter 1, pp. 12-13.
2. Dominique, J.; Tobler, J.D. (2016). “Effect of pH on Amorphous Calcium Carbonate Structure and Transformation”, Crystal Growth & Design, 16, pp. 4500-4508. 3. Ogino, S.S. (1987). “The Formation and Transformation Mechanism of Calcium Carbonate in Water”. Geochimica et Cosmochimica Acta, Vol 51, pp. 2757-2767.
4. Denzinger, W.; Hartmann, H.; Goeckel, U.; Richter, F.; Winkler, E.; Raubenheimer, H.-J. (April 4, 1989). “Polymaleic Acid, Its Preparation, and its Use”, U.S. Patent No. 4,818,795.
5. Yamaguchi, S.; Shioji, S.; Shorbu, I.; Yoshio, F.; Fujiwara, T. (Aug. 4, 1989). “Process for Producing Acid-Type Maleic Acid Polymer and Water-Treating Agent and Detergent Additive Containing said Polymer”, U.S. Patent No. 5,135,677.
6. Rodrigues, K.; Eknoian, M.; Crossman, M. (June 20, 2006). “Hydrophobically Modified Solution Polymers and their Use in Surface-Protecting Formulations”, U.S. Patent No. 7,063.895. 7. Standish, M. (Oct. 29-Nov.1, 2014). “Ground Up: Designing New Polymers for Independent Water Treatment Companies”, presented at 2014 AWT Convention, Fort Worth, TX. 8. GuiCai, Z.; JiJiang, G.; MingQin, S.; BinLin, P.; Tao, M.; ZhaoZheng, S. (February 2007). “Investigation of Scale Ininhibition Mechanisms Based on the Effect of Scale Inhibitor on Calcium Carbonate Crystal Forms”, Science in China Series B: Chemistry 50(1), pp. 114-120. 9. Boffardi, B.P. (1986). Fundamentals of Cooling Water Treatment, Calgon, Pittsburgh, PA, pp. 72-75.
Glossary of Abbreviations
Ca: calcium CaCO3: calcium carbonate CH: methine CH 2: methylene CH3: methyl CPVC: chlorinated polyvinyl chloride CoC: cycles of concentration Fe: Iron HMC: hydrophobically modified copolymers Li: lithium LSI: Langelier Saturation Index Mg: magnesium mg/L: milligrams per liter mL: milliliter Mw: weight average molecular weight Mn: number average molecular weight NMR: nuclear magnetic resonance OH: hydroxyl PMAs: polymaleics PMA: polymaleic acid PMA-AQ: Polymaleic synthesized in an aqueous system PMA-S: Polymaleic synthesized in a solvent system PD: polydispersity ppm: parts per million SEM: scanning electron microscope
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Klin Rodrigues, Ph.D., is a principal scientist in the Polymer PPR Group at Nouryon. He has been with Alco Chemical/AkzoNobel/Nouryon for more than 23 years. Dr. Rodrigues has authored 30 technical papers and holds more than 75 U.S. patents. He holds a doctorate in polymer science and a master’s degree in chemical engineering from the University of Akron. He earned his bachelor’s degree in chemical engineering from the Indian Institute of Technology Bombay (India). Dr. Rodrigues can be contacted at klin.rodrigues@nouryon.com. Jan Sanders is a senior researcher in the Polymer PPR Group at Nouryon. She earned a B.A. in chemistry from the University of Tennessee–Chattanooga in 1999. Ms. Sanders joined Alco Chemical/AkzoNobel/Nouryon in 1998 and is an expert on applications methods for scale control in oil field and water treatment. She has four U.S. patents and has co-authored several publications. Ms. Sanders may be reached at jannifer. sanders@nouryon.com. This article is based on a paper presented at the 2018 AWT Annual Conference, which was conducted Sept. 26–29, 2018, in Orlando, Florida. © 2019 Akzo Nobel Surface Chemistry LLC
the Analyst Volume 26 Number 1
Industry Notes ResinTech’s Peter Meyers Awarded the IWC Merit Award at the International Water Conference
H2O contributions to the ion exchange industry, the field of water treatment, and ResinTech over his impressive career. His long list of lectures and white papers demonstrates his commitment to inspiring the next generation of water technology engineers.”
H SO
4 U.S.2Water Supports the Grassy Waters Everglades Preserve in West Palm Beach, Florida Left to right: ResinTech representatives Joel Tiss, Michael Gottlieb, Peter Meyers, and Frank DeSilva.
ResinTech, Inc. is pleased to announce that its senior technical director, Peter Meyers, is the 2018 recipient of the IWC Merit Award. The International Water Conference® presents the Annual Merit Award to honor an inspiring individual in the field of industrial water technology—a person who has continually demonstrated outstanding leadership and made significant contributions to water-related technology or the advancement of its application. IWC Award presenter Trisha Scroggin, from Burns & McDonnell, introduced the award by saying, “Peter Meyers has presented papers or discussions more than 21 times over 30 years here at the IWC, and with every single paper or presentation, he pushes passion and excellence.” Meyers took the opportunity to emphasize the importance of engaging the next generation in improving water technologies, saying, “Change is going to happen whether we want it to or not. Change has to happen to the IWC, and I hope we stay relevant.” Meyers continued, “We can’t keep doing the same thing over and over. We have to try new things, and if those new things don’t work, we have to put them aside and try something else.” ResinTech CEO Jeffrey Gottlieb summarized the feelings of Meyer’s co-workers and industry peers, stating, “We are incredibly proud of Peter for his many significant 50
In September 2018, the Grassy Waters Everglades Preserve expanded its habitat garden with the help of U.S. Water and area manager Justin Treece. Treece and other local volunteers planted trees native to the area and the everglades in the Preserve’s growing habitat garden. Treece, who’s has been in the water treatment industry for 11 years and frequents the preserve with this family, understands the importance of protecting freshwater resources like Grassy Waters. The Preserve is an expansive wetlands ecosystem that serves as the freshwater supply for the city of West Palm Beach, South Palm Beach, and Palm Beach Island. The trees, purchased with the help of U.S. Water, will help attract wildlife to the preserve that will continue to sustain this important ecosystem.
Dr. Michael Topka Joins Spectra Colors Corporation
Michael Topka, Ph.D., has joined Spectra Colors Corporation as an analytic chemist. His background in dyes and years in research will be an asset for new product development and research. Spectra is very proud to be serving our customers for 30 years with high quality of service, products, and color matching. For more information, visit http://spectracolors.com.
Tiarco Adds Capacity at Dalton Plant
Tiarco Chemical boosted capacity at its Dalton chemical production facility in a multi-million-dollar expansion that will be fully operational by the second quarter of 2018. The chemical site increased its footprint by about 40 percent, from about 70,000 square feet to about 100,000 the Analyst Volume 26 Number 1
Industry Notes continued
square feet, said Kevin Nolan, vice president and general manager at Tiarco Chemical. Construction of the new unit began in the first quarter of 2017.
Tiarco will expand its facilities at Greenville, South Carolina, and Ipoh, Malaysia. He said both also focus on component chemistries.
The site produces a variety of components used in the manufacture of latex additives, grease and lubricant additives, water treatment additives, and contract and toll manufacturing. Within the latex industry, the site is focused heavily on antioxidants, accelerators, and wax emulsions.
Grundfos to Clean and Recycle Its Own Wastewater
He added there were three primary drivers for the expansion—improving efficiencies of operation, adding a level of automation and control to production, and increasing capacity. The Dalton chemical plant runs three key manufacturing processes for Tiarco that will be increased with the expansion. The first and largest is reactive chemistry.
No contaminated sewage will make it into nature when the new wastewater treatment plant opens at Grundfos in Bjerringbro, Denmark. The system collects and cleans wastewater from the paint plant, making the water clean enough for another round of production. The closed-loop facility is part of Grundfos’ goal to cut 50 percent of its water consumption by 2025 compared to 2008. It is also one of the company’s efforts to solve global water challenges.
The other two manufacturing processes are production of aqueous dispersions and emulsion capabilities.
“Sustainability is an integral part of all our products and services. Naturally, this also applies to our factories. The new plant shows how our technology can make a positive difference, and that we take responsibility for our production leaving the smallest possible footprint on the environment. It is one of the ways we contribute to sustainable development goal 6,” says Stéphane Simonetta, group executive vice president of operations, referring to the UN’s global target to ensure sustainable water solutions.
The expansion gave the company the chance to design and build equipment where those manufacturing processes are in full control for both safety and controlled repeatability, said Nolan.
The plant, underway for the past two years, is expected to save 10,000 m3 of water per year—equivalent to the anuual consumption of 100 ordinary Danish households. Innovative methods make it possible.
While Tiarco is not adding a large amount of base chemistry in the latex market, “we are setting up the manufacturing capability to add to our current portfolio, as well as leave room for new chemistries in the future,” Nolan said.
“The processing plant is packed with our newest technologies. Using digital sensors, microfiltration, smart dosing, and of course of our pumps, we can treat water for painting processes to a level where it can be recycled. The plant is a live-working showcase of how wastewater can be turned into value,” explains Anders Lund Hansen, senior manufacturing director.
“We’re a true manufacturing chemical company where we design, scale up, produce, and sell molecules. In this case, the ones for the latex industries are accelerators basically for curing latex,” Nolan said.
“The current expansion will improve our ability to deliver solutions to meet our waterborne customers’ future needs. Latex is one of our core strengths, not only for Tiarco, but also for the entire family of Textile Rubber & Chemical Companies. We intend to maintain a leadership position in the latex market on technology and application solutions,” said Nolan.
The new water treatment plant opened officially on Friday 30 November at Grundfos in Bjerringbro and featured speeches from Group President Mads Nipper, Stéphane Simonetta, and Anders Lund Hansen, among others.
The expansion at the Dalton facility comes before two additional major developments over the next two years. 51
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Industry Notes continued
Advantage Controls Promotes Jeff O’Neal to President
Advantage Controls, a Muskogee (Okla.)-based manufacturer of industrial water treatment equipment, announced this week the promotion of Jeff O’Neal to the position of company president. He will be responsible for overseeing all aspects of the company’s daily operations and long-term strategic planning. “Jeff is a gifted individual with proven leadership skills. My expectation and belief is that he will take Advantage Controls far beyond where we are, and the time has come for me to get out of the way!” said Dan Morris, Advantage Controls CEO.
O’Neal, 43, joined the company in 1997 as an inside sales representative and quickly rose to multiple management positions including regional sales manager, vice president of sales, and most recently, vice president of operations. O’Neal received a bachelor of business administration in management from the University of Oklahoma, where he graduated with distinction. He is currently a board member with the Eastern Workforce Board and serves as vice chairman of the Greater Muskogee Manufacturers Alliance. He is also a certified Lean Implementer and the recipient of a Governor’s Commendation for workforce development.
Water Treatment Just Got A Lot Easier The new LIQUITRON™ 7000 Series Multi-Parameter Controller is fully equipped and ready to control your boiler, cooling tower, pH, and ORP water treatment applications from a single unit. Enable LMI Connect™, cloud-based software, to manage your process remotely from anywhere. Choosing the right controller has never been easier! Visit lmipumps.com or RelyOnLMI.com to find a stocking distributor near you.
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the Analyst Volume 26 Number 1
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Association News
AWT Benchmarking Survey
Drop by Drop: Articles on Industrial Water Treatment, by James McDonald, CWT
AWT will once again be conducting a financial operations study. Participation in this survey is very important, as the data can: Provide our industry with current statistics. Identify developing trends (e.g., sales mix or customer mix). Help members understand the risks and opportunities associated with potential highs and lows that have been experienced. AWT has hired Industry Insights, an independent research firm that specializes in confidential surveys, to manage this study. This professional survey firm will never divulge individual company responses to any entity, including AWT. Be sure to complete the survey to receive: 1. A free copy of the complete Benchmarking Report. 2. A free Company Performance Report, personalized for your company based on the study’s findings and your individual company’s responses. 3. Complimentary access to the study’s Searchable Results online application, allowing you to create customized data cuts based on criteria that are most meaningful to you.
Drop by Drop is a compilation of technical articles on various aspects of industrial water treatment, including boilers, cooling towers, closed loops, wastewater, pretreatment, chemistry, calculations, equipment, and testing. Like a bucket can be filled “drop by drop,” each stand-alone article will add to the reader’s knowledge base in an easy-to-read format that gets to the practical heart of the matter. With a wide breadth of topics covered, both novices and seasoned veterans will find something of interest in this 485-page book. This valuable publication is available for purchase through the AWT bookstore at www.awt.org.
2019 AWT Training Seminars
The AWT 2019 Training Seminars will help you refine the skills needed for success in the water treatment industry. Essential to all water treatment professionals, no matter the stage in one’s career, these programs provide high-quality technical training that is convenient, cost-effective, and informative. Material presented is noncommercial and emphasizes practical, hands-on information that can be used in everyday situations. The seminars focus on the primary areas of industrial and commercial cooling and boiler water treatment. Don’t miss out on the opportunity to make your mark in the industry, review best practices, or fill in any learning gaps. For more information, visit www.awt.org.
4. A complimentary STEM kit that you can use at your local school. To ensure that you receive all of the benefits of participation, please complete the survey upon receipt.
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SPECIALTY PRODUCTS Mid South NPRR (Neutral pH Rust Remover) Inhibited Propylene Glycol 30% NSF NONFOOD Inhibited Propylene Glycol & Inhibited Ethylene Glycol Mid South TT50S (sodium tolyltriazole 50%) DEHA and Carbohydrazide oxygen scavengers Super Blue Deicer (liquid deicer) BZT liquids (acid & alkaline blends) MCT 519 Closed Loop inhibitor for systems with aluminum
NSF ANSI/60 Zinc/Orthophosphate Polyphosphate Ortho/Polyphosphate RO Membrane treatments
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DOW ACUMER™ POLYMER Acumer 1000 Polyacrylic acid Acumer 2000 Carboxylic sulfonated copolymer Acumer 3100 Carboxylic sulfonated terpolymer Acumer 4161 Phosphino polycarboxylic acid Acumer 4300 Maleic multipolymer Acumer 5000 Silica control polymer
Mid South Chemical Company, Inc.
info@midsouthchemical.com www.midsouthchemical.com Main Office 318 894-7301 Sales Office 830 935-2078 Distributor Sales Hotline 800 264-6055
Membership Benefits
Safety Training Courses AWT has partnered with The Marcom Group, Ltd. to provide online safety training courses for professionals in the water treatment industry. The program allows you to train, test, and track the safety training of you and/or your employees. There are hundreds of courses to choose from, and the system offers you easy reporting tools to monitor training progress. Learn more at https://www. awt.org/education_events/safety_training_courses/. Water Treatment Training When you purchase access to the Water Treatment LearningSource program, you will gain access to the following courses for one year: Fundamentals of Water Treatment: Thirteen courses provide the fundamentals of four areas: basic math, basic chemistry, properties of water, and safe handling of chemicals. Cooling Fundamental Program: Five courses provide an overview of the basics of cooling water treatment, cooling towers, equipment, and the water treatment triangle. Advanced Cooling Program: Eight courses provide an in-depth review of cooling, including microbiological control, deposition fundamentals, and corrosion. Reverse Osmosis Program: Three courses review the fundamentals, operations, and maintenance of basic reverse osmosis systems. Water and Waste Program: Seven courses, including filtration processes, sludge dewatering, and clarification fundamentals. Boiler Program: Three courses cover the fundamentals of boiler treatment.
Introduction to Water Treatment Online Modules If you’ve hired some new staff members who will be going on technical calls for your company, AWT has launched a new online training module that will help you to get them trained quickly. From the role of a service technician to transporting products, Introduction to Water Treatment will walk your team members through the entire service call process. This online training is only available to AWT members and it’s free. New modules will be released as they are completed. Modules include: • • • • • • • • • • • • • •
Role of a Service Technician (available now) Properties of Water (available now) Boiler Equipment (available now) Pretreatment Equipment Cooling Equipment Basic Water Chemistry Common Water Treatment Components Basic Water Treatment Calculations Installing Water Treatment Equipment Maintaining Water Treatment Equipment (available now) Inspections Testing Recordkeeping and Reporting Transporting Products
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POWERING
POTENTIAL
T.U.T.O.R.
Technical Updates, Tips, or Reviews
Water Essentials
How to Select the Right Metering for a Treatment Process By Laith Charles, Pulsafeeder SPO
Metering pumps are the conduit between good chemistry and a controlled process. There are limitless applications for chemical metering equipment, ranging from agriculture and car washes to water treatment for boilers, cooling towers, and wastewater. While the fundamentals of selecting the right metering pump are common throughout all applications, some application-specific considerations can be overlooked. This article is intended as a reference to pump fundamentals as well as some application-specific tips to serve as a useful refresher for some and an educational reference for others.
Diaphragm Pumps The rubber meets the road in the head of a diaphragm pump. The core components of a diaphragm pump are the suction valve, discharge valve, and reciprocating diaphragm. Other than the drive mechanism—solenoid or motor driven—the principals of diaphragm pumps are the same. Fundamentally, all diaphragm pumps have a suction and a discharge stroke, which is shown in Figure 1. Figure 1: Stroke styles of a diaphragm pump: suction (left) and discharge (right).
Before we begin, here is one important reminder for the expert or the beginner: always remember to take the appropriate safety precautions when working with metering equipment. Wear personal protective equipment (PPE) when handling chemicals, while in loud equipment rooms, and when working on electrical equipment. Now, let us look at the essentials for successfully using a chemical metering pump for water treatment applications.
Core Metering Technologies
A plethora of different technologies are available when it comes to choosing a chemical feed pump. Pump technologies include: diaphragm, peristaltic, piston, progressive cavity, gear, hose, and more. Alternatives to metering pumps are also worth mentioning, such as a venture and pot feeder, and solid feeders, such as a brominator.
The suction stroke is when the diaphragm retracts backwards from the forward position, increasing the distance between the surface of the diaphragm and the inner wall of the head. This increases the volume inside the pump head and causes a decrease in pressure, “The suction stroke is when the diaphragm which creates a vacuum retracts backwards from the forward because of the Ideal position.” Gas Law, as shown in Equation 1.
It is important to know all options and their respective strengths and weaknesses. With this knowledge, one can make sure to choose the right equipment the first time to balance cost, performance, and reliability. Nonetheless, the scope of this article will be limited to metering pumps, specifically diaphragm and peristaltic.
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Ideal Gas Law: P1V1 = P2V2
Equation 1
This vacuum, or negative pressure, creates suction, which the Analyst Volume 26 Number 1
T.U.T.O.R. continued
flexible piece of tubing. Positive displacement is created applies inward pressure that pulls down on the discharge as the rollers inside the head contact the tubing, creating valve, creating a seal as the check ball seats firmly in a pinch point, and rotate the seat. Conversely, around, causing suction the vacuum also pulls “The volume displaced from a single head on the suction side and up on the suction valve positive output pressure and lifts the check ball revolution in a peristaltic pump is fixed on the discharge side. from its respective seat, based on the size of the tube.” The pinch points in a allowing the negative peristaltic pump are the pressure to be equalized “seals” in the pump and the rotation of the pinch points by the higher pressure in the suction line. that causes a volume change, creating the suction and discharge pressure, allowing the pump to operate. The discharge stroke is when the diaphragm moves forward or decreases the distance between the surface The volume displaced from a single head revolution in of the diaphragm and the inner wall of the head. This a peristaltic pump is fixed based on the size of the tube. increases the pressure in the head as volume decreases. Output can be varied by adjusting the speed or rotaAs the pressure builds, the force pushes outward evenly. tions per minute of the pump head. Because the suction This pressure pushes down on the suction valve, firmly and discharge stroke occurs simultaneously, one would seating the check ball. The same pressure also pushes up assume the output of a peristaltic pump to be more on the discharge valve and allows the higher-pressure consistent; however, the pump operation will create fluid in the head to diffuse into the discharge line. varying fluid acceleration and some pressure swings as each roller goes by the discharge valve. Figure 2 illusDiaphragm pumps only feed into the process during the trates how a peristaltic pump works. discharge stroke. During the suction stroke, there is no output. This causes a unique pulsating output. Adjusting the output of a diaphragm pump is done by either Figure 2: Cross section of a peristaltic pump that illustrates how it works. adjusting the stroke length, which changes the volume in the head displaced during every stroke, or by changing the speed of the pump stroke.
Peristaltic Pump Another staple in the metering pump world is the peristaltic pump. The function of the pump is similar— both dose repeatable and accurate quantities of chemical. Even so, the contrasting pump topologies operate quite differently. A peristaltic pump’s head consists of a suction and discharge side. The “wetted” liquid end of the pump is a
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Comparison of Technologies
Table 1 provides a comparison on how diaphragm and peristaltic pumps work. Table 1: Comparison of diaphragm and peristaltic pumps. Diaphragm
Peristaltic
Controls
Adjustable stroke, length, and speed
Adjustable speed
Chemical compatibility
Wide variety of liquid end materials
Limited to tube compatibility
Discharge pressure
Able to operate beyond 300 psi
Limited to less than 125 psi
Suction lift
5 ft
24 ft
Output
Up to 132 gph
Limited to 100 gpd
Maintenance
Lower maintenance
Higher maintenance
Other notes
• •
• • •
Excellent repeatability Check balls do not perform well with chemical slurry
Output drifts with tube age Excellent self-priming performance Performs better with chemical slurry
Table notes: Numerical data in table above is only reflective of equipment made by Pulsafeeder. Other manufacturers and specialized equipment ratings may differ. This reference in the table is intended as a guide to give examples of the general characteristics of diaphragm and peristaltic chemical feed pumps. psi = pounds per square inch ft = feet gpd = gallons per day gph = gallons per hour
Table 1 outlines some of the differences between typical diaphragm and peristaltic pumps. Some of these differences cause one pump to excel over another in a given application. From a chemical compatibility standpoint, you typically have better coverage on a diaphragm pump when working with chemicals that are more aggressive. Dialing in the head material, the elastomers and the check balls enable one to find a combination that works well with the chemistry being injected. Conversely, peristaltic pumps have a narrower compatible range. The output capability on pressure, flow, liquid end-life, and accuracy are all better with the diaphragm technology; however, the “self-priming” nature of a peristaltic pump makes it a favorite for many. Additionally, it offers heightened performance with small-suspended solids. Suspended solids will sit on the valves inside a typical diaphragm pump and interfere with the check balls seating, which prevents the pump from functioning. Lastly, when it comes to suction-lift capacity or
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the ability of a pump to lift fluid up to the pump head, a peristaltic pump performs better.
Site Survey
Knowing a little about these two styles of pump, their respective strengths and weaknesses help during the next part of the selection process— the site survey. No one pump is right for all applications. Engineers must tailor a lot of equipment selection based on the site’s unique needs. There can be several unique aspects affecting pump selection: the treatment process, the chemical, and power or input/output (I/O) requirements at the installation.
Environment The first factor to observe is the environment. Will the equipment be outside in direct sunlight or inside in a nice climate-controlled room? Other environmental factors worth noting would be any extreme humidity and/or altitude conditions, as these can sometimes affect
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equipment performance. A pump selected for an outside agricultural application versus a pump used for a water conditioning plant would have drastically different environmental considerations.
Location Next, getting an idea on the location of the equipment is important. Even if you are only taking over an account, sometimes keeping equipment exactly where it was could be setting you up for failure. Keep in mind the limitations of the equipment. Avoid unnecessarily long suction and discharge runs. If you can store chemical close to the point of injection, then do so. Also, ensure the point of injection makes sense in the process to maximize chemical dispersion. Another important consideration is the pump’s location relative to the chemical. Do not exceed the maximum
suction-life requirement of the pump. Any time a diaphragm pump is installed in a suction-lift application, use a foot valve to help in priming the pump and maintaining prime. Keep the foot valve upright. In certain applications, you may need to install a pump in a flooded suction situation to handle high viscosity or off-gassing fluid. Ensure the head orientation is correct when mounting a diaphragm pump because head rotation is sometimes required. Lastly, if ever there is a sensitive fixed asset at a facility, factor in a “What if…?” risk analysis. Unfortunately, double-containment is often implemented after a chemical spill. Do not wait! If you do wait, then you might lose an account or face an unexpected liability because of this oversight. Figure 3 shows schematics of four mounting options for a pump and its chemical solution tank.
Figure 3: Various mounting configurations possible for chemical dosing pumps.
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Other Factors
Besides the chemistry, you want to know exactly where the pumps are being plugged in and if there are any other electrical interface cabling factors that should be considered. Many times, pumps are plugged into a wall-mounted controller that is only a few feet from the pumps. In these applications, simply ensuring that the pigtail plug is the same form factor as the one on the pump is often enough; however, certain applications use custom programmable logic controllers (PLC) that require conduit wiring. Be sure to know the voltages and phases of the power you need to run the equipment. In addition, equipment sometimes needs power where there is none. There may not be an outlet or controller to simply plug a 115VAC plug into. Here, one needs to get creative and implement a complete power solution with a gas generator or even solar setup complete with batteries to provide equipment power.
Pump Selection
Knowing the fundamentals of metering equipment can help immensely when designing and implementing a chemical solution for a process. When you are in tune with the underlying mechanics of metering equipment, troubleshooting often becomes a mental brainstorming exercise to figure out the root cause of a given issue. Let us take a step back for a minute and revisit the basics. Our first stop when dialing in the right pump for an application is as follows: • Chemical compatibility • Pump output • Pressure requirements • Electrical I/O • Fluid considerations Chemical compatibility. When working with chemicals, it is paramount to ensure that everything that touches the chemical is chemical resistant. Everything from the containment tank, up through the foot valve, suction tubing, pump head, discharge tubing, and injector must be able to withstand the chemical coursing through it. If you are not sure, confirm with the chemical supplier and the pump manufacturer. Pump output. Sizing a pump is also pivotal. If the location has a 5 gph of chemical demand, then confirm 62
that the selected pump can handle that throughput. Oversizing a pump is often useful as process demands can change and cause a spike in the chemical demand. Sizing a pump at 70% gives reasonable turn up and turn down to adjust to process changes. Pressure requirements. All pumps have a maximum pressure rating. One needs to ensure the process pressure and additional stack-up pressure are below a pump’s pressure rating. Again, oversizing and building in cushion can protect against being painted into a corner where you might need a new pump. Keep in mind, long discharge tubing runs will increase the pressure seen by the pump. Fluid is heavy and sometimes viscous, and moving it, especially up, creates additional work for your dosing equipment. Electrical I/O. Equipment needs power, and there are many different kinds of power supplies. Become familiar with AC/DC (not the band) and the different voltages, amps, and phases needed to power the equipment and respective safety ratings. Beyond power, know the control inputs needs, 4-20 milliamps (mA), pulse inputs, and stop signals. Fluid considerations. Pumps used in potable water applications would need an NSF-61 rating. (Note: The NSF International is a standards developing organization that develops guidelines for the performance of equipment in water treatment and other areas.) When working with high-viscosity fluids or oxidizers, a specialized liquid end might be needed. Certain applications and/or processes involve a pump skid complete with calibration columns, pulsation dampeners, pressure relief, backpressure valves, and more. Often, multiple pumps match the requirements of a specific installation. In these instances, one can have the luxury of choosing equipment based on personal preferences. While many equipment decisions happen subconsciously, as one grows more and more familiar with the needs of each process, sometimes slowing down and taking a more “blank slate” approach can reveal a small oversight where the “go-to” or default equipment choice would not have done the job.
Pump Degassing
Metering equipment feed a plethora of different chemicals. A common agent to dose into a process is an oxidant. This group of chemicals is widely used as a the Analyst Volume 26 Number 1
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disinfection agent. While there are several different oxidants available, it is important to respond appropriately to dose them accurately. As examples, sodium hypochlorite, chlorine, and bromine can be difficult to feed accurately. Many of these chemicals, depending on conditions, are unstable in their liquid state. The chemicals want to oxidize and turn into a gas. Gases in nature behave dramatically different from liquids. Gases are quite compressible versus their liquid counterpart. This important behavioral trait makes it difficult for a standard diaphragm pump to purge gas in the pump head against pressure.
Frequently Overlooked
Here are some prevailing themes of often-overlooked considerations that include anything from suction tubing on the discharge side to a chemical compatibility oversight. The following is a list of areas to watch out for that can contribute to successful operation of diaphragm and peristaltic pumps: Foot valve orientation. A foot valve needs to be upright. A check ball inside foot valves helps diaphragm pumps prime and maintain prime. A foot valve on its side will not serve its function and will hurt pump performance.
Pump head orientation. A diaphragm pump head A degas head is designed specifically for oxidants. This should be vertical, the suction valve on the bottom, and feature allows for safe gas-chemical venting back to the discharge valve on the top (or side for a degas head). the containment tank. If mounting a pump by Once any built up gas its feet, rotate the head “A continuously operating metering pump is purged, the venting accordingly along with can stroke over 100 million times a year.” mechanism seals and the weep valve on the allows the primed pump adapter plate. to resume normal operation. Long vertical discharge runs. A cooling tower on a roof The correct installation of the return line is to secure with feed equipment in the basement compounds the the line back in the chemical containment tank above pressure seen by the pump. Avoid long vertical discharge the liquid level. Submerging the return line contributes runs when possible and only oversize pump pressure some backpressure on the venting mechanism and can output when unavoidable. cause performance issues. Additionally, long suction and discharge tubing runs can compound this phenomenon. Flooded suction required. High fluid specific gravity, Sometimes supplemental inline gas vents are required to viscosity, or certain oxidizers will only behave well in maintain performance. flooded suction. Suction lift ratings must be prorated for these difficult chemicals, but sometimes, flooded suction is the only installation method that will work. Maintenance A continuously operating metering pump can stroke over Backpressure adds consistency. Backpressure can 100 million times a year. Even a metering pump that prevent variations in pump output and reduce the risk turns on for one hour every other day still comfortably of syphoning. Use backpressure in a flooded suction strokes more than 1 million times in a year. The demand and when process pressure is inconsistent for optimal on a pump head is high. As a result, maintenance is huge performance. when it comes to keeping pump performance at its best. KOP, or “Keep on Pumping” kits, are recommended annually. New check balls, seats, diaphragm, tubes, and seals all contribute to a pump’s accuracy and performance. Often, pumps are used indefinitely until they simply stop working; however, building in preventative maintenance schedules can normalize equipment costs for a process and reduce the chance of down time.
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Do not rob Peter to pay Paul. If a pump goes down, scrounging up parts to get the pump working is an art. Be careful taking one pump’s component and using it on another pump. Mixing these components is a slippery slope to accidentally mixing chemicals with incompatible materials.
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T.U.T.O.R. continued
Degassing considerations. Oxidizers must be handled appropriately, so pump degassing is a wise practice when working with these chemicals.
Conclusion
Regardless of whether one has been working with metering equipment for 30 years or 30 days, no one is perfect. If not done already, one will eventually make a mistake in choosing the proper equipment for a process or just installing the equipment incorrectly. Some mistakes could lead to not feeding any chemicals for a month, while others might cause a full tote of chemicals to be dumped preemptively into a process within a few days. It is difficult to predict every case in some applications that could adversely affect metering equipment. Everyone develops a set of â&#x20AC;&#x153;go-toâ&#x20AC;? equipment and even has a typical installation setup. This can help drive consistency in various site visits. One may have a pump you are comfortable with, know how to rebuild, and maybe already have spare parts lying around in case of an emergency.
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Sometimes the best pump is simply the one that is there in the plant and works. However, one may not always have pump equipment that fits your typical equipment selection. Be aware of the dosing equipment needs in each process and factor in considerations for the process variables like output, pressure, and compatibility. Scope out your installation conditions, and minimize unnecessary chemical tubing runs. Make sure your equipment can interface with any other existing system when applicable and be aware of any unique environmental conditions that might lead to special equipment considerations. Laith Charles is the Pacific Northwest regional manager for Pulsafeeder. At Pulsafeeder, he has worked in the engineering department, with a focus on product development for both controllers and pumps. Mr. Charles holds a B.S. in electrical engineering from the University of Central Florida. He may be contacted at LCharles@idexcorp.com.
the Analyst Volume 26 Number 1
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Making a Splash
Mike Standish
Radical Polymers Chattanooga, Tennessee
What prompted you to start volunteering with AWT?
I started my water treatment career in 1986 as a co-op student. Soon after graduating college, I began attending AWT meetings as an additive supplier. What impressed me at the time is how willing the membership was to help me as a young person with very little experience or knowledge. I cannot overemphasize this quality of the membership. I believe this trait is special and unique within AWT and is at the core of the purpose of the association. So, this being a part of the DNA of AWT, it had to become a part of my DNA as I grew in my experience and could begin to contribute to other members and the overall needs of the organization.
What has been the most rewarding thing about volunteering?
Everyone knows “it is better to give than to receive.” Certainly, it is rewarding to be able to help the organization or another member directly. However, it is definitely never a one-way street. I have always found instant gratification when volunteering within AWT. At a minimum, I always learn something during these opportunities to volunteer. It might be learning about a business challenge facing the membership, becoming aware of a new regulation, or having to do a bit of technical research to be able to answer a question. Additionally, there is a tremendous amount of camaraderie and fellowship within the committees. Contributing, learning, and developing friendships are all pretty compelling rewards for being involved in AWT.
How has volunteering improved your professional career?
“Networking” is a pretty overused term nowadays, but I think that has to be my answer here. This being said, I would also add to that the component of developing trust within the networking relationships. Like most everyone I know who has been involved in AWT for any appreciable 66
amount of time, I have developed relationships that are so much deeper than a network or contact list. It is pretty powerful to be able to have a group of “go to” people when you have a question you don’t know the answer to or an opportunity that you aren’t sure how to approach in the best way. It is even more powerful to be called on and trusted for advice when someone in your “network” values your opinion. Volunteering within AWT absolutely has provided those connections for me throughout my career.
Why would you encourage others to become a volunteer?
I truly don’t think the answer here is about obligation or “you need to give back.” For me, it is really not about that. It is more about being part of the AWT community. Collectively, the membership of AWT is a greater resource than any single company entity, whether large and global or small and local. I would encourage anyone to tap into that resource, develop strong bonds with your colleagues, learn from the collective knowledge and experience, and yes, contribute with his or her own expertise and ideas.
Tell us about a current project you or your committee is working on?
One of the primary objectives within the Business Resources Committee is to develop a strong platform of useful topics for the Business Owners Meeting. In the last couple of years, this meeting has grown from an idea within the committee to an additional day at the annual convention. In February, we will hold our first standalone Business Owners Meeting in New Orleans. The committee is very excited about this opportunity to contribute business-focused support to the membership. We believe providing on point information and training for current business issues facing the membership is a vital component to helping member companies grow their businesses. We encourage anyone to become involved, contribute ideas, and join us in New Orleans. the Analyst Volume 26 Number 1
CWT Spotlight
Chandler Mancusco, CWT Technical Coordinator Plymouth Technology, Inc.
How did you prepare for the test?
The AWT Technical Reference and Training Manual was my lifeline. I spent countless hours reviewing it cover to cover. As a younger water treatment professional, I felt that it was important to do my best to translate the knowledge that I was gaining from the TRTM to the field, so I did this at every opportunity I had, and it forced me to learn the information in a way that was majorly beneficial for the purpose of taking the exam.
What are the advantages of having the CWT designation?
By far the most significant benefit that I have experienced from achieving my CWT was that it sort of opened the door to establish contact with some of the best water treatment experts in the industry. I know that I have so much more to learn about this industry and water treatment, so the feeling that I can continue to learn from my colleagues and use resources that I didn’t have in the past is really exciting to me.
What was the most difficult aspect of the exam?
For me, the most difficult aspect of the exam was simply the volume of material that one must master in order to pass it. It was intimidating, and to accommodate this, I did not try to cram anything into my head because I knew I wouldn’t be able to get away with doing that for an exam of this magnitude. Instead, I carefully studied smaller sections of material just about every day, and I would not move forward to new material until I was confident that I understood everything from the previous section to avoid convolution.
What advice would you give those thinking about taking the exam?
The exam is difficult, and it takes a lot of time to prepare for it, but the benefits of taking it are innumerable. You will be a better water treater, you will find yourself more centered in the industry, and I am confident all CWTs would agree that it was well worth going the distance.
Congratulations to Our Newest CWTs Please join us in congratulating the latest individuals to become CWTs (October 15, 2018–January 15, 2019)
Tim Minamyer, CWT Aqua-Serv Engineers, Inc.
Paul McKennon, CWT Aqua-Serv Engineers, Inc.
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Matt Fogle, CWT Aqua-Serv Engineers, Inc.
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Ask the Experts The discussion below occurred on AWT’s online community, the Exchange. Be sure to join to be part of the conversation!
Copper Deposits in a High-Pressure Boiler Question 1
Curious to hear thoughts on copper deposition in a boiler system running at 850 psi. They have 3 admiralty brass FW heaters and 1 admiralty brass condenser. Significant deposits have been found in the boiler feedwater valves in the steam header, deposits in the steam drum and mud drum. Numerous tube failures have occurred, however we believe that is FAC related. They operate the feedwater pH between 8.8 and 9.2 and condensate pH between 8.5 and 9.2. I’m assuming pH attack on the admiralty brass as I can’t find anything else to point at it. Copper levels tested in the 53-100 ppb levels. What should the pH be at for this type of system? Can ammonia be an issue considering different polymers being used currently in the system? Thanks in advance for the help.
Answer 1 Your pH’s in the feedwater are too high. They should not exceed 8.5. What is causing your high pH’s? Where and what are you feeding for your chemistries? Copper will cause localized galvanic corrosion, which, under certain stresses, can crack a tube. Recommend you have a metallurgist examine the tube and the failures, especially if you are assuming FAC. Answer 2 My experience is with higher pressure boilers where a pH for mixed metallurgies of 8.8–9.2 is recommended, with an ammonia concentration of < 0.40 ppm. Excessive oxygen can cause severe copper corrosion (something to consider). Also as mentioned a root cause analysis should be performed to confirm tube failure mechanism. Answer 3 On these lower pressure generating boiler systems, you will often find copper and copper alloys in the system. Failures of the copper are mainly due to overdosing the amine (or ammonia) in the presence of excess dissolved oxygen. Most can be prevented with adequate oxygen scavenger (in this case, a non-solids DO scavenger) and 68
low ammonia or amine dosing. With a system like this, if you are using the AVT(O) chemistry approach, it becomes more difficult to control.
Answer 4 How is your oxygen control? Where is the makeup coming in and what percent makeup do you have. Where are you feeding the oxygen scavenger? Do you export steam at varying rates, or is the system reasonably steady? Better not be on AVT-O unless a completely steel system!
Response 1
Thank you everyone for all your help on this. DEHA is being fed to the DA as the AVT-O and a triblend SLT is being fed prior to the 3 brass feedwater heaters (no idea why, not my account…yet). I’m looking at this like pH is the major factor, need to do a DO test on the DA. Recent high-purity feedwater analysis showed 26 ppb of zinc and 14 ppb of copper. Any thoughts on what levels these need to be at for concern? Iron was nd.
Answer 5 Those are elevated. Copper is usually several times higher than zinc in brass. While there is such a thing as dezincification, over time everything on surface comes off the surface of brass in feedwater. So if you see that much zinc, average copper transport is probably higher than indicated by that one test. Some of the copper also can plate on boiler feed pumps and first heater after the deaerator during service but you can get a slug of a bunch more copper transport when it redissolves with oxygenated water on startup. Control of air in leakage, DO, and ammonia can be critical. Look at ASME guide for limits of copper as a function of pressure.
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Capital Eyes
How Can Congress Get Things Done in 2019? By Janet Kopenhaver
In my last column, I provided a recap of the November election, including the fact that starting in 2019, we will again have a divided government, with the White House and Senate held by Republicans and the House by Democrats. However, I added that this might actually result in some substantial legislation being passed because both the White House and the House Democrats want to prove to voters that they can get things done to set the stage for the 2020 presidential elections. But it will not be easy, as partisan politics is so pervasive nowadays. Here are problem areas that, if fixed by Congress, would alleviate gridlock in the Capitol. Gerrymandering – The redistricting process and thus the lack of competitive seats gets a lot of the blame for the dysfunction in Congress. The result of gerrymandering is that a disproportionate majority of Americans live in politically homogenous communities. Consider this statistic: In 2010, one of every four districts (or 109) were considered somewhat competitive between the parties. Eight years and one nationwide redistricting later, this number shrunk to only about 18 percent (or 77 seats). In other words, in five of six districts, securing one party’s nomination is tantamount to winning an election in November. Fundraising – Another major problem is the amount of time legislators need to spend on fundraising, leaving little time for actually legislating and cultivating relationships with their colleagues across the aisle. There is also the problem of candidates’ beliefs that in order to get donations, they must resort to the most partisan language possible to build up their base. Consider this statistic: the total spent on all congressional contests has surged 73 percent since the start 69
of this century, surpassing $4 billion in 2016. And it is sure to continue increasing each year. Through the mid-year of 2018, fundraising averages were $7.5 million for an incumbent senator seeking reelection and $1.3 million for a House member seeking another term. Media – Voters are tending more and more to ignore or reject information that calls into question their own ideological views of the world. Instead they are relying exclusively on newspapers, websites, and cable news networks with a tone that reinforces their pre-existing perception of what is important, who is respectable, and what constitutes “fake news.” Consider this statistic: A national survey last summer found that 57 percent of the Fox News audience identifies as Republican, and only about one in five of its viewers said they voted for Hillary Clinton. On the other hand, 60 percent of CNN viewers and 64 percent of MSNBC viewers identify as leaning or solidly Democratic. Mingling – It is very difficult to create and establish a functional and collaborative legislature when half the members have no personal interaction with the other half. The congressional schedule (along with fundraising mentioned above) is a big problem. Legislators usually fly in on Monday night or Tuesday morning in time for the week’s first vote and head to the airport right after a last roll call, which is most often on Thursday. In addition, fewer and fewer politicians find homes in the Washington area and move their families here. That has resulted in the virtual disappearance of the bipartisan family barbeques that helped define member culture in the 1970s, when going home on weekends was difficult due to Monday morning and Friday afternoon votes. Continued on p. 71 the Analyst Volume 26 Number 1
Financial Matters
Tax Cuts and Jobs Act Supercharges Exemption Portability The Tax Cuts and Jobs Act (TCJA) completely rewrites sections of the tax code for individuals and businesses. Under the TCJA, the federal gift and estate tax exemption doubles from $5 million to $10 million, indexed for inflation to $11.18 million in 2018.
the portability provision, the executor of the estate of the first spouse to die can elect to have the “deceased spousal unused exclusion” (DSUE) transferred to the estate of the surviving spouse.
Somewhat lost in the clamor is the fact that the new law preserves the “portability” provision for married couples. Portability allows your estate to elect to permit your surviving spouse to use any of your available estate tax exemption that is unused at your death.
A good way to explain the DSUE is to look at a hypothetical example. Let’s say that Kevin and Debbie, who have two children, each own $5 million individually and $10 million jointly with rights of survivorship, for a total of $20 million. Under their wills, all assets pass first to the surviving spouse and then to the children.
The long and winding road
In addition to the unlimited marital deduction that shelters asset transfers between spouses from federal estate tax, the $11.18 million gift and estate tax exemption covers asset transfers to other heirs, such as your children and grandchildren. (See the sidebar “Don’t skip the generation-skipping transfer tax.”) It doesn’t seem possible, but at the turn of the century, the exemption was a mere $675,000 before being hiked to $1 million. Subsequently, the Economic Growth and Tax Relief Reconciliation Act of 2001 gradually increased the exemption to $3.5 million, while reducing the top estate tax rate from 55% to 35%, among other changes. After a one-year estate tax moratorium in 2010, the Tax Relief Act (TRA) of 2010 reinstated the estate tax with a generous $5 million exemption, indexed for inflation, and a top 35% tax rate. The American Taxpayer Relief Act (ATRA) of 2012 made these changes permanent, with the exception of increasing the top rate to 40%. Along the way, the unified gift and estate tax exemption was severed and then reunified, as they remain under current law. Thus, any amounts used to cover lifetime gifts erode the remaining estate tax shelter. Most important, for the first time, the TRA authorized portability of the estate tax exemption, which was then permanently preserved by ATRA. Under 70
How DSUE works
If Debbie dies in early 2018, the $5 million in assets she leaves to Kevin is exempt from estate tax because of the unlimited marital deduction. Thus, her entire $11.18 million exemption is unused. However, if the election is made upon her death, Kevin’s estate can later use the $11.18 million of the DSUE from Debbie, plus the exemption for the year in which Kevin dies, to shelter the remaining $8.8 million from tax, with plenty to spare for some appreciation in value. What would have happened without the portability provision? For simplicity, let’s say that Kevin dies later in 2018. Without being able to benefit from the unused portion of Debbie’s exemption, the $11.18 million exemption for Kevin in 2018 leaves the $8.8 million subject to estate tax. At the 40% rate, the federal estate tax bill would amount to a whopping $3.52 million. Although techniques such as a traditional bypass trust may be used to avoid or reduce estate tax liability, this example demonstrates the potential impact of the portability election. It also emphasizes the need for advance planning.
Other points of interest
Be aware that this discussion factors in only federal estate taxes. State estate taxes may also have a significant impact, particularly in some states where the estate tax exemption isn’t tied to the federal exemption. the Analyst Volume 26 Number 1
Financial Matters continued
Capital Eyes continued
Also, keep in mind that, absent further legislation, the exemption amount is slated to revert to pre-2018 levels after 2025. Portability continues, although for those whose estates will no longer be fully sheltered, additional planning should be considered.
Masochism – Members have been told by their constituents for so long that they do terrible work in a terrible place. Many then win their seats by poking fun at the very place where they want to work. This leads to more and more of them taking actions that overtly disrespect the institution, reinforcing the voters’ expectations and deservedly driving the reputation of Congress lower and lower.
Furthermore, portability isn’t always the best option. All relevant factors should be considered, including nontax reasons that might affect the distribution of assets under a will or living trust. For instance, a person may want to divide assets in other ways if matters are complicated by a divorce, a second marriage, or unusual circumstances. Your estate tax advisor can help you decide if portability is right for your estate plan.
Don’t skip the generation-skipping transfer tax If you leave assets to your grandchildren or even younger heirs, either through your will or living trust, the transfer is subject to the generation-skipping transfer (GST) tax. This is separate from regular federal estate tax. Fortunately, your estate is protected by the GST tax exemption. This exemption, which is the same figure as the estate tax exemption, is indexed to $11.18 million in 2018 under the Tax Cuts and Jobs Act. The GST tax rate is 40%.
Consider this statistic: Gallup’s monthly measurement of congressional approval has not cracked above 40 percent since early 2005 and has been in the teens in all but one month of this year. So, what do we need to have a successful and productive Congress? A place where money is not an obsession, where mapmaking does not determine election results, where media outlets are less partisan in their reporting, where members of Congress socialize more with each other, and where institutional masochism is replaced with some self-respect. Certainly a very high lift, but our country’s future depends on it. Janet Kopenhaver is president of Eye on Washington and serves as the AWT Washington representative. She can be reached at (703) 528-7822 or janetk@eyeonwashington.com.
But there’s a potential pitfall for individuals. Unlike the estate tax exemption, there’s no portability with the GST tax exemption. Each estate stands on its own. To avoid problems, ensure that the GST tax exemption is properly allocated when making transfers to heirs two or more generations below you. © 2018 Thomson Reuters
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Business Notes
Make Your New Year’s Goals Stick! By Steve McClatchy, President, Alleer Training & Consulting
How did you do last year with your New Year’s resolutions? Are you celebrating with jubilation from accomplishing all of them? Did you follow through on your promises to yourself to improve your life, relationships, wealth, health, and happiness? No? Well, don’t be too hard on yourself; lots of people will make the same resolutions this year that they made last year, and the year before. It usually goes something like this. You resolve to lose weight, write a book, get a new job, go to graduate school, etc. You might even write it down on your to-do list. But by the time the Girl Scouts show up to sell their cookies in February, the resolution is forgotten. So why do so many fail and so few succeed at achieving their goals and resolutions? The key to your success or failure is found in a little difference between your to-do list and your calendar. The most successful people don’t let their planning stop with their to-do list. They take out their calendar and make sure they have their most important priorities scheduled and defended. If someone were to ask if you were available this Thursday for a meeting, the first thing you would do is check your calendar. If your calendar says you’re busy on Thursday, you would decline the invitation and steer your meeting toward another day. Notice that you did not check your to-do list for Thursday, you checked your calendar. This little difference in the way you treat tasks and appointments can be vitally important to your success or failure in achieving your goals and resolutions. These two tools that most people use to help their brain manage daily life—the to-do list and the calendar—do not serve the same purpose. Your to-do list contains a list of tasks that are time flexible, to which you have not assigned specific times to complete. Your calendar, on the other hand, contains a list of tasks that are time specific, to which you have assigned specific times to complete. As a result of these time-specific 72
commitments, you have given yourself a lot more work to do. Each time something comes up, you will now have to reference these commitments to make sure you don’t double book yourself. You will have to defend them against other tasks or appointments that want the same time slot. You will now have to work everything else around completing this specific task at this specific time. This appointment will influence what you can do, where you can be and who you can be with before it and after it. Do you see all the extra work that is involved in putting an appointment on your calendar? Because of the extra work involved in scheduling them, working around them, and defending them repeatedly, we reserve appointments on the calendar for what is most important. If you are going to go through all of this, it better be important! There is another problem we face when it comes to improvement in our lives: our maintenance items. Maintenance items include your morning routine, eating three meals a day, dishes, trash, laundry, bills, haircuts, grocery shopping, car maintenance, house maintenance, taxes, sleeping, voice mails, emails, reports, expenses, budgets, meetings, presentations and everything in life that would eventually be brought to your attention if you didn’t do it. The problem with maintenance items is that life creates them every day. There is never a time when they are complete because they repeat. We don’t check off the task of putting gas in the car. Every mile you drive means that task is going to repeat soon. This is what happens with all your maintenance items. If there is always a maintenance item to do, then you could spend all of your time doing them, and catching up would always be just out of reach. You can always find something that needs to be maintained, cleaned, fixed, fed, paid, filled up, or emptied out. If you can fill all your time with maintenance, then there is no time in life for goals and improvement! Wait, let me say that again. There is no time in life for goals!
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Business Notes continued
To have goals in your life, you have to “make time.” The question isn’t, “is there time for goals?” The question is, “how far are you willing to be behind on your maintenance items to have goals in your life?” “Making time” is an expression we use to describe the process of putting the commitment on our calendar, defending it, working around it, and deciding to put off our maintenance items because of it. That is the process we call “making time.” This is the key to success with your New Year’s resolutions, your goals in your business, your personal life, and anything that you want to accomplish. What in your life is worth planning, scheduling, defending, and being behind on your maintenance items because of it? What step can you take today to make your life better, reduce your stress, move your business forward, or improve your important relationships? Is it exercise, creating a budget, finding a mentor, scheduling a date night, benchmarking the competition, fixing a broken system at work, networking, or enrolling in a training class? If these things are not scheduled and defended, they will not happen. There are some things in life that you remember for a year, five years, a decade, or even a lifetime. Goals and resolutions fall into this category. How long will you remember getting a degree or advanced degree, learning a new musical instrument, documenting your family tree, getting a new job, presenting at a big industry convention, or writing an article that gets published? These things are much more memorable than your commute to work, paying your bills, taking out the trash, picking up your dry cleaning, or submitting your monthly report. When you look at the results that come from moving things forward, achieving your goals, learning new things, or gaining more experience, you will see that these things are worth defending. They are worth all the trouble and extra work that comes from placing them on your calendar and committing to them.
Achieving goals and resolutions is possible, and a lot of people are successful with them each year. Each year in the United States, over 100,000 people graduate with an MBA degree, over 300,000 books are published, over 500,000 people run marathons, and over 6 million people take piano lessons. You can search these and other statistics online very quickly for inspiration. Don’t just dream of a goal, add it to a to-do list, and leave it to chance. Take the final step needed to make it a reality! Use your calendar as a weapon to move your life forward. Make this your year for progress, growth, improvement, and happiness. Make this your year for results! Steve McClatchy is the president of Alleer Training & Consulting and the author of the award-winning New York Times bestseller Decide: Work Smarter, Reduce Your Stress and Lead by Example. Steve provides keynotes and workshops on the topics of Leadership, Time Management, Consultative Selling, and New Business Development. If you would like to learn more about the ways Alleer can be a resource to your organization, visit www.Alleer.com, email Steve@Alleer.com, or call (800) 860-1171.
When you see how these accomplishments and improvements contribute to your self-esteem, confidence, and outlook on life, you’ll see that these things are worth defending and not leaving to chance. Make a list of your loftiest goals for life or what you want to change for tomorrow. Then take one small piece off your to-do list and put it on your calendar today so you can make it happen. 73
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Advertising Index 57 Albemarle Corporation
55 Mid South Chemical Company
31 AMSA, Inc.
38 Myron L Company
33 AquaPhoenix Scientific Inc.
65 North Metal & Chemical Company
7
2
Bio-Source, Inc.
Pulsafeeder, Inc.
21 Brenntag North America
37 QualiChem, Inc.
24 Browne Laboratories, Inc.
5
64 Chem-Met Company
74 Scranton Associates, Inc.
15 Environmental Safety Technologies, Inc.
76 Special Pathogens Laboratory
25 H2trOnics
53 Tintometer
41 IDEXX
19 Walchem, IWAKI America Inc.
52 LMI Pumps
75 Water Science Technologies
74
Sanipur US LLC
the Analyst Volume 26 Number 1
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