Water Pollutants and their Sources & Control Of The Water Pollution

Water Pollutants and their Sources

The variois types of water pollutants are:-

1) Oxyres-demanding wastes :-

These Include domestic and aninal sewage, bio-degradable organic compounds'and industrial wastes from food-processing plants, meat-packing plants, slaughter houses paper and pulp mills, tunnerjes etc, as well as agricultural run-off. All these wastes undergo degradation and decomposition by bacterial activity in presence of dissolved oxygen This result in rapid depletion of D.O. from the water, which is harmful to aqualic organisms. The optimum D.O. in natural waters is 4-6 ppm, which is essential for supporting aquatic life Any decrease in this D.O. value is an index of pollution


2) Disease-causing wastes :-

These include pathogenic microorganisms which may enter the war along with sewage and other wastes and may cause tremendous damage to public heath These microbes comprising mainlyof viruses and bacteria can cause dangerous water borne diseases such as cholera, typhoid, dysentry, polio and infectious hepatitis in humans. Hence, disinfection is the primary step in water poilution contrọl.

3) Synthetic Organic Compounds :-

These are the man-made materials such as synthetic pesticides, synthetie detergents (syndets), food additives, pharmaceuticals, insecticides, paints syuthetic fibres, elastormers, solvents, plasticizers, plastics and other industrial chemicals. These chemicals may enter the hydresphere either by spillage during transport and use or by intentional or accidental release of wastes from their manufacturing establishments. Most of these chemicals are potentially toxic to plants, animals and humans.


4) Sewage and agriculfural run-off :-

Sewage and run-off from agricultural lands supply plant nutrients, which may stimulate the growth of algae and other aquatic weeds in the receiving water body. This unwieldy plant-growth results in the degradation of the value of the water body, inimded for ecreational and other uses.


5) Oil :-

Oli pollotion may take place because of spills from cargo oil tae tenker on seas losses during off shore exploration and prosuctien of oil accidental fires in ships and oli tanker deal accidental or Intentional  oli slicks (as in the Gulf War between iraq and U.S led allied forces in the year 1991) and leskage fom oil pipe lines, crossing waterways and resevoirs  oil pollution resuts in reduction of light transmission thrugh surface weter, therdy reduing photo synthensid by marinne plants oil pollution in seas han been Increasing due to the increase in oil based technologies tive oil massive oil shipments, accidental oil spillages etc

1) Inorganic Pollutants :-

Inorganic pollutants comprise of mineral acids, inorganic salts, finely dividedmetals or metal compounds, trace elements, cyanides, sulphates, nitrates, organometallic compounds and complexes of metals with organics present in natural waters. The metal-organic interactionszinvolve natural organic species, such as fulvic acids and synthetic organic species, such as EDTA. The heavy metals such as Hg, Cd and Lead/metalloids such as As, Sb and Se are most toxic. The water pollution by heavy metals occurs mostly due to street dust, domestic sewage and industrial effluents. Polyphosphates from detergents are also water pollutants.


2) HEAT :-

Considerable thermal pollution results from thermal power plants, particularly the nuclear-power-based electricity generating plants. In such industries, where the water is used as a coolant, the waste hot water is returmed to the original water bodies. Hence the temperature of the water body increases. This rise in temperature decreases the DO content of water, which adversely affects the aquatic life.

 > Control Of The Water Pollution

1.)Scientific techniques are necessary to be adopted for the environmental control of catchment areas of rivers, lakes, ponds or streams

2) The possible reuse or recycle of treated sewage effluents and industrial wastes should be emphasized and encouraged.

3) Instead of throwing wastes in to water, the recycling should be done for bette use Gobar gas plant, composting, manufacture of hardboard, paper. etc, such examples where respective waste can be used.

4) Minimum, appropriate quantity and concentration of Fertilizers, pesticide-& insecticides should be used, because excess will cause pollution.

5) There should be propaganda for water pollution-control, on radio, TV Newspapers etc. because public awareness is a must.

6) Treatment plants should be
constructed and Govt should also help by funding for domestic, sewage and industrial effluents

7) Local authorities, Industrialists, Govt officials, with public participation should co-ardinate to finds ways to control water pollution.

8) Water resources should be used in the best possible economic way

9) To conduct seminars and training courses for helping those, who are directly or indirectly engaged in water management and water pollution control.