physical water by Rajiali

Physical water quality parameters Raji A. Mousa Erciyes university – Turkish The physical properties of water include temperature, color, taste, turbidity, and suspended solids. The maximum recommended Temperature limit set by NDWQS Adjective Unit of measure (scale) Allowable limits Temperature °C 35 Color Pt / Co 10 Taste --Acceptable Turbidity NTU 5 T.S.S MG|L 25

1-Temperature The temperature of water affects some of the important physical properties of water Chemical and biological reaction rates increase with increasing temperature. Reaction rates usually assumed to double for an increase in temperature of 10 °C. The temperature of water in streams and rivers throughout the world varies from (0 – 35) °C. Increased temperature increases the viscosity of wastewater and increases the sedimentation of suspended particles.

1-1 importance of temperature Affects chemical reactions during the wastewater treatment process. Oxygen solubility is less in worm water than cold water. Optimum temperature for bacterial activity is in the range of (25 -350) °C Aerobic digestion and nitrification stop when the temperature rises to 500 C. When the temperature drops to about 15°c, methane producing bacteria become in active. Nitrifying bacteria stop activity at about 5°c. 1

The metabolic rates of aquatic organisms increase as the water temperature increases. Temperature affects the photosynthetic rates of different algae, algal photosynthesis will increase with temperature. 2- Taste Pure water is always tasteless ,therefore if any types of taste is present, it indicates water pollution. Water taste may develops due to natural or artificial regions. Artificial region for taste and odor in water is due to disinfection process (chlorination). Some natural impurities dissolved in water can also give taste and odor. Compounds giving taste to water may be toxic to consumer, so drinking water should be taste less and odor less. Taste - If the water has a metallic taste, the water may be contained elevated levels of metals, such as: Iron, Manganese, Copper, Lead, Zinc and other metals. Salty taste: High levels of naturally occurring sodium, magnesium, or potassium may cause a salty taste. factors that contribute to taste and odor in wastewater are mostly due to presence of chemical compounds, norganic salts such as NaCl, KCl etc dissolve in water give taste whereas compounds like H2S can give both taste and odor.

3- Color It’s possible for the color of the water to be altered by materials that decay from organic matter, which include vegetation, Such inorganic matter as rocks, soil, and stones may also affect the color of the water. Even though these changes to a water’s color may create aesthetic issues with the water, they don’t change how the water tastes. You can effectively measure color by comparing a water sample to color glass disks or standard color solutions. When you’re attempting to identify the color of water, it’s important to understand the difference between the water’s apparent color and its true color. Apparent color is made up of suspended material and dissolved solid colors.

The true color of water can be identified after all suspended materials have been filtered out of the water. Color has the following effect on the amount of water: • water is not aesthetically pleasing to the general public. • Highly colored water is unsuitable for washing, dyeing , papermaking, beverage manufacturing, dairy production and other food industries, textile production and plastics. Thus, the color of the water affects its marketability for both domestic and industrial use. Some industrial sewage also add color to domestic wastewater. The grey, dark grey and black color is due to formation of sulfide produced under anaerobic conditions reacts with the metals present in wastewater (Haseeb Jamal , 2017) It has been estimated that annually up to 12% of the synthetic dyes used in textile manufacturing operations can be found in dye wastewater effluent. After being processed in treatment plants (Ken Phillips ,2013)

4-Total Suspended Solids (T.S.S) Total Suspended Solids could be anything that floats or “suspends” in water, including sand, sediment, and plankton. Total Suspended Solids is a measurement of the total solids in a water or wastewater sample that are retained by filtration. Total Suspended Solids refers to waterborne particles that exceed 2 microns in size. Any particle that is smaller than 2 microns, on the other hand, is considered a total dissolved solid. The majority of total suspended solids comprise of inorganic materials; however, algae and bacteria may also be considered T.S.S When certain water sources are contaminated with decaying plants or animals, the organic particles released into the water are usually suspended solids. While some sediment will settle at the bottom of a water source, other TSS will float on water’s surface or remain suspended somewhere in between. Total Suspended Solids affects water’s clarity, so the higher a water source’s T.S.S content, the less clear .

4-1 Why is total Suspended Solids important?! 3

T.S.S is an important water quality parameter measure for wastewater treatment operations and environmental health. Wastewater contains large quantities of suspended organic and inorganic material that must be removed through screening, filtration or settling. TSS will also have adverse affects on UV disinfection blocking/scattering UV light bound for pathogen disinfection or alternatively requiring higher intensity for proper disinfection, increasing energy costs. If total Suspended Solids is not removed properly through treatment, high concentrations can lower the water quality in the receiving environment. The suspended solids absorb light, causing increased water temperature and decreased oxygen which creates an unfavorable environment for aquatic life. Total suspended solids is the dry-weight of suspended particles, that are not dissolved, in a sample of water that can be trapped by a filter that is analyzed using a filtration apparatus. It is a water quality parameter used to assess the quality of a specimen of any type of water or water body, ocean water for example, or wastewater after treatment in a wastewater treatment plant. T.S.S in mg / L can be calculated as: (dry weight of residue and filter - dry weight of filter alone, in grams)/ mL of sample * 1,000,000

5- Turbidity Turbidity is the cloudiness of water caused by a variety of particles and is another key parameter in drinking water analysis. It is also related to the content of diseases causing organisms in water, which may come from soil runoff. Turbidity is a measure of the turbidity of water due to suspended matter such as organic matter, fats, mud, algae, plankton, and microorganisms. Most turbidity in surface water results from the erosion of colloidal material such as clay, silt, rock fragments and metal oxides from the soil. Vegetable fibres and micro-organisms also contribute to turbidity. Household and industrial waste water may contain a wide variety of turbidity producing materials. Soaps, detergent and emulsifying agents produce stable colloids that result in]turbidity. Turbidity has the following adverse impacts on the quality of water:

(a) The colloidal material associated with turbidity provides adsorption sites for chemicals that may be harmful or cause undesirable tastes and odours and for biological organisms that may be harmful. (b) Turbidity may impart a brown or other color to water in natural water bodies depending upon the light absorbing properties of the solids and may interfere with the light penetration and photosynthetic reactions in streams and lakes. (c) Accumulation of turbidity causing particles in porous stream beds results in sediment deposits that can adversely affect the flora and fauna of the stream. Some materials that give turbidity may be toxic to consumers. Therefore turbid water is not suitable for drinking purposes. Furthermore turbidity decrease efficiency of disinfection process. Drinking water should have turbidity less than 5 NTU (Naphthalometric turbidity unit) 5-1 Turbidity Ratings According to the World Health Organization (WHO) the turbidity of water for human consumption should not exceed (5) NTU and ideally be below 1 NTU.  Good (<1 NTU) - It is recommended that newborns and people with compromised immune systems drink boiled water or a safe alternative.  Fair (1-5 NTU) - It is recommended that children, the elderly, people with compromised immune systems and anyone seeking additional protection drink boiled water or a safe alternative.  Poor (>5 NTU) - It is recommended that all users drink boiled water or a safe alternative. Tap water intended for drinking should be brought to a rolling boil for at least one minute. 5-2 Treatment Turbidity is commonly treated using either a settling or filtration process. Depending on the application, chemical reagents will be dosed into the wastewater stream to increase the effectiveness of the settling or filtration process. Potable water treatment and municipal wastewater plants often remove turbidity with a combination of sand filtration, settling tanks, and clarifiers.

5-3 Color and turbidity

Color and turbidity are two water quality parameters that detract from the appearance of water, making it unpleasing to drink for aesthetic reasons. Color is organic material that has dissolved into solution, while turbidity consists of tiny particles suspended in the water column. It is the organic material in the watershed that causes both color and turbidity. While color and turbidity are present at low levels for most of the year, they are particularly visible during spring run off (May - June). Turbidity is a critical parameter in drinking water because bacteria, viruses and parasites can attach themselves to the suspended particles. In addition, particles in turbid water can interfere with disinfection by shielding contaminants from the disinfectant. The water is treated with sufficient amounts of chlorine to ensure that an adequate chlorine residual remains in the water to effectively disinfect any pathogens that may be present 5- 4 What is the difference between turbidity and T.S.S? Even though turbidity and total Suspended Solids complement each other, they are both influenced differently. Turbidity can be measured from a sample with an instant read while measuring the total suspended solids is a process that has to be performed again in the laboratory. total Suspended Solids can calculate sedimentation rates, while turbidity cannot. The permissible limit for turbidity in water quality is 5 NTU, while in suspended solids it is 25 MG|L . The important question remains, is it possible to convert one of them to the other, and the answer is not possible, as there is no linear relationship between them, despite considering turbidity and total suspended solids as indicators of water quality.

Physical water quality parameters…Case studies in Iraq 1- In a study conducted within the borders of the city of Basra in Iraq, it was shown that the value of suspended solids for river water was (2964) mg per liter and for sewage water was (3014) mg per liter. The amount of suspended solids at the bottom of the rivers was because it is affected by sands of household waste. 6

The higher values were due to pollution in the water, high temperature and increased evaporation (Dunia Al-Khuzai 2014). 2-In this study, Al-Diwaniyah River within Al- Diwaniyah Governorate was monitored for a set of physical, parameters for the assessment of water quality during January to July 2018. for this river were plotted to represent the change in each parameter during the study period using GIS program. Three sampling stations along the river and parameters were selected water temperature, turbidity, total suspended solids. The results explained that the water temperature varied between (15-31) °C T.S.S (13.63) NTU (13.71) MG|L (Khalid M. Hussein., et al 2019) ……………………………………………………………………. Locations Turbidity 1 2 3 4 5

6.4 -30.5 3.4 – 36.4 2.6 – 44.7 1.2 – 56.3 1.5 – 40.1

Temperature

T.S.S

9.5-29.4 9.7- 29.1 10.4 – 29.2 10.5 – 29.7 29.8 – 29.8

6.5 – 56.4 1.6 – 50.0 0.3 – 70.9 0.4 – 68.5 0.3 – 81.0

Average 13.4 21.3 20.3 3- A study was conducted (Aqil Al-Sharifi 2014) to evaluate the water quality in five sites in Karbala governorate in 2014. The results are shown in the following table Possible pollution of some heavy metals and some environmental factors of the streams of Bani Hassan - Karbala

Table showing the temperature of water, turbidity and suspended solids

References  Physical and chemical properties of water in Basra - Iraq 2014  Khalid M. Hussein , Sataa A.F. Al-Bayati, Salih A.A. Al-Bakri(2019) Assessing Water Quality for Al-Diwaniyah River, Iraq Using GIS Technique. Engineering and technology Journal Vol. 37, Part A, No. 7  Al-Sharifi, Aqil Abass (2014) Possible pollution of some heavy metals and some environmental factors For the water of Bani Hassan Creek - Karbala | Iraq  Ken Phillips (2013) What scale is used to measure the color of waste water?  Haseeb , Jamal(2017) physical characteristics of sewage With regards Raji Ail 5-11-2021