“Industrial Waste Water Management “ 13.30-15.30 Hours India Water Week 2013 Ramani Iyer CII National Water Council 9th April,2013 Vigyan Bhawan,New Delhi
Industrial Waste Water Management in Indian industry
Contents of the presentation What is Zero Water discharge? Merits & Challenges Approach to zero water discharge Strategies for Zero water discharge Methods to achieve zero water discharge Best practices
What is Zero Water Discharge? Recovery of reusable water/ other materials from waste water
Minimization or, no discharge of polluting substances
Merits & Challenges of Zero Water Discharge Merits Reducing fresh water consumption and avoiding effluents Important contribution to environmental protection
Challenges Additional initial costs Installation of additional equipment /systems Ex: Softeners, De-mineralisers, UF, RO membranes
Approach to Zero water discharge Segregate waste streams based on quality of waste water generated
3 pronged approach
Treat as appropriate (Primary, Secondary & tertiary)
Recover and reuse in process (low & high end applications)
Ultimately leading to reduction in fresh water consumption
Strategies for zero water discharge Segregate waste water streams based on quality of waste water generated Suspended solids & TDS Oil & grease BOD & COD Color & Odor Toxic trace elements
Treat as appropriate Primary, Secondary & tertiary
Design of Zero water discharge systems ď ś Factors to be considered 1. Quality of the waste water to be treated 2. Ability & efficiency to handle varying effluent loads 3. Performance degradation of the machinery over a period of time 4. Operation and maintenance issues 5. Mass-balance under varying operating conditions
Methods to achieve zero water discharge Reduction at source-examples Installation of Waste heat recovery boilers & Air cooled condensor Optimize nozzle size with oscillating shower in paper machines Use of adiabatic coolers
Methods to achieve Zero water discharge Reuse & recycle-examples High end Process Re use of treated secondary clarified water as boiler feed water in paper plants Utilities Process cooling Cooling tower make up
Low end Irrigation & gardening, Toilet flushing, Floor washing, Dust suppression, Ash quenching etc.
Case study-1
Zero water discharge in petroleum refinery CPCL, Chennai
Zero water discharge, CPCL, Chennai Two zero water discharge plants ~8400 m3/day Total investment ~Rs.15 crores Percentage of treated effluent in daily consumption -45% 65% fed to DM plant Green belt development
Major treatment methods Suspended particle removal using PSF Ultra filtration RO
Case study-2
Zero water discharge in chemical industry Godrej Industries Ltd., Valia
Zero water discharge- Godrej, Valia Effluent streams Low COD & Low TDS- 300 m3/day Sources- DM plant regeneration, filter back wash & Cooling tower blow down Treatment-Clarifier-UF-RO Reuse- TDS-50 ppm in CT make up
Low TDS & High COD-175 m3/day Process & sewage Treatment-UASB reactor Reuse-COD <150 ppm for CT make up & gardening
Zero water discharge- Godrej, Valia High TDS – 15 m3/day Scrubber waste water High sodium sulphite content Sold to outside party
High TDS & Low COD- 15 m3/day
Total investment Rs.125 lakhs Water saving-90,000 m3/yr Payback-30 months
Case study-3
Zero water discharge in PVC & Chlor-Alkali plant Chemplast, Mettur
Zero water discharge Chemplast-Mettur Installed plants for PVC & Chlor alkali plant Investment ~Rs.27 crores Operational cost~Rs.6 crores
Approach To reduce the effluent load 2000 m3/day to 1100 m3/day Through in house measures
Treat it appropriately
Results Reduction in effluent discharge from 0.7 mn m3/ annum to zero discharge Water saving 10 mn m3/annum
Case study-3
Zero water discharge in automobile industry Mahindra & Mahindra, Nashik
Zero Water dischargeMahindra & Mahindra, Nashik Effluent generation~800 m3/day Process Component washing Paint booths
Utilities Cooling towers Filter backwash
Sewage
Percentage of treated effluent in daily consumption 35% in process Rest green belt development
Zero water dischargeMahindra & Mahindra, Nashik Applications of treated water Forklifts & Plant vehicle washings Press shop body panel washing Fire hydrant. Paint stripping unit ETP/STP process. Gardening within the plant. Toilet urinals flushing & cleaning.
Investment ~ Rs.32 lakhs Water saving ~ 50,000 m3/annum
Sum up Enormous potential exists Fresh water saving Reduction in environmental pollution Water intensive sectors Ex:Pulp & paper, Power, Petrochemical etc.,
Recovery & reuse of useful chemicals Replication of best practices CII-Triveni Water Institute Advisory services Zero water discharge facilitation
Water audits Training programs