48. NCERT Exemplar XXX

 

Water pollution is a change in the physical, biological, or chemical properties of water (due to the addition of foreign organic, inorganic, biological or radioactive substances) that has a negative impact on aquatic life and makes water unfit for use. Water pollution is caused by a number of factors.

(i). DustSewageDrainage: It is a dirty substance carried in large underground drains known as sewers and consists primarily of organic waste. In towns and cities, it is the primary source of water pollution. It causes eutrophication by increasing the nutrient load of water bodies.

(ii). Industrial wastesHousehold wastesDomestic wastes: Industrial wastes (including organic and inorganic chemicals) contain large quantities of harmful chemicals, including acids and alkalies, discharged into water bodies. Radioactive substances, such as mercury, are sometimes found in industrial waste.

(iii). Synthetic paste and detergentsSynthetic soaps and detergentsSynthetic soaps and soap oil: Grey water is water that contains soaps and detergents. These pollutants are discharged from houses and certain factories pollute the water supply, making it unsafe for human consumption.

(iv). Pesticides and detergentsDetergents and FertilisersFertilisers and pesticides: Fertilisers and pesticides are used extensively in fields to promote crop productivity, and rains wash them into bodies of water, polluting them.

(v). Gas spillswaste spillsOil spills: Drilling and shipping operations in the oceans sometimes result in petroleum leakage, resulting in the destruction of ocean flora and fauna.

(vi). HeatIceCool: The release of hot water from power plants raises water temperatures and lowers dissolved oxygen levels, killing aquatic organisms.

(vii). Unhydric habitsHygienic habitsUnhygienic habits: Bathing humans and animals, washing clothes, defecation, etc., near water bodies is another major cause of water pollution in India. Water pollution can be significantly reduced by taking the following steps.

The sewage should not be directly discharged into the water body. Treatment of sewage should convert sewage's harmful substances into harmless ones.

(i). Throwing of garbage and domestic wastes in the lantwaterair body should be prohibited.

(ii). Dumping of toxic wastes from industries should be causeallowprevented by legal restrictions.

(iii). Trees should be planted near the river banks to check soil erosion which would otherwise cause siltation of lantairwater bodies.

The use of fertilisers and pesticides should be considerably reduced and farmers should be encouraged to switch to harmless organic manures and other eco-friendly methodologies of farming.