Effect Of Pollutants On Water Quality

Subhendu (2000) and Farkas et al. (2000) have reported several effects of pollution on the physico-chemical properties of water.

• Light: High turbidity and colour variation of water bodies reduced the penetration amount of light.

• Temperature fluctuation: The temperature of water increased during thermal pollution where water is used for cooling power stations and also waste heat from industries.

• Depth and flow: Both flow and depth of the water body decreased due to heavy siltation of sediments coming from land erosion.

• pH: Acidic water due to siltation or burning of coal and oil causes fluctuation in the pH of the water body. Large amount of acids are being generated from mines and several industrial processes such as DDT from factory wastes, batteries, tanneries and vinegar.

• Dissolved Oxygen: Dissolved oxygen levels get depleted due to heavy sewage pollution and discharge of wastes containing high organic matter into any water body. The dissolved ones are also broken down by the physiological activity of microorganisms using O2.

• CO2: Due to eutrophication and organic pollutants, dissolved oxygen depletes from the water body with increase in CO2 levels, due to decomposition of undissolved organic matter.

• Alkalinity: Wastes from tanning, wool scouring, mercerizing of cotton and manufacture of certain chemicals industries (particularly in chloro-alkali industries) contain caustic soda, sodium carbonate or lime. These alkaline wastes have pH range between 12-14, which becomes lethal to all types of aquatic life.

• Salinity: Salinity increases dissolved oxygen level by excessive amount of salts transported from sewage, effluents and chloro-alkali industries which increases chloride level and thereby salinity of water, which is further responsible for increasing osmotic pressure.

• Colour and Turbidity: Colour of water also changed due to fluctuation in dye, pigment and turbidity of water. Turbidity increased due to soil erosion or heavy algal bloom caused by high load of organic and inorganic nutrients both from industries or agricultural effluents.

• Nitrates and Phosphates: Water runoff by agricultural effluents, soil erosion and organic pollutants i.e. from sewage and synthetic detergents) are rich in nitrates and phosphate content.

• Heavy metals: In natural water, various trace elements are present in very small and trace amounts such as Hg, Ni, Zn, Cd, Mn, Pb, Cu, Cr, Fe, As, Se etc. Increase in the amount of heavy metal can alter the water quality. Exposure cadmium caused anemia, discoloration of teeth, damage to olfactory nerve, ulceration of nasal septum, rhinitis, and anosmia to aquatic organisms (Maurya et al., 2019).

• Eutrophication: Eutrophication also impacts water quality directly or indirectly. Water pollution from domestic sewage increases organic load and also pollution from agricultural runoff which contains huge amounts of nutrients such as potassium, nitrates; phosphates, etc. fertilize water and increase the rate of productivity of aquatic ecosystem. This process results in complex growth of phytoplankton. The water becomes turbid due to the extreme increase of phytoplankton and suspended particles by soil erosion.

Read Also:

1. Some Of Other Pollutants In Ecosystem
2. Types Of Emerging Pollutants And Negative Impacts
3. A Review On The Effects Of Water Pollution On Freshwater Fish Species
4. Water Pollution: Causes, Negative Effects And Prevention Methods
5. Effects And Control Ways of Water Pollution
6. Causes Of Water Pollution
7. Introduction To Water Pollution
8. Introduction To Air Quality And Pollution Control