question_answer 74)

  What are the causes of water pollution? Discuss how you can contribute in reducing water pollution.

Answer:

  Different causes of air pollution are (i) Industrial wastes Effluents of mills and industries such as paper mills, petroleum refineries, etc., contain large quantities of harmful chemicals including acids, alkalies and heavy metals, (e.g., mercury salts from paper industries). These chemicals are discharge into water bodies (rivers and lakes). (ii) Synthetic soaps and detergents Water containing soaps and detergents is discharged into rivers, from houses and certain factories. (iii) Fertilizers and pesticides Fertilizers and pesticides are being used excessively in the fields to increase crop production. These are washed by rainwater into water bodies and pollute them. (iv) Petroleum oil Drilling and shipping operations are common in the oceans. Leakage of petroleum oil during such operations or due to accidents [i.e.. oil spill) cause water pollution. (v) Solid particles Rain erodes soil and carries silt to water. Tiny suspended particles of clay and dust also settle in water. These soil particles cause turbidity in water. (vi) Thermal pollution Discharge of hot water from industries and thermal plants into water body changes the normal temperature of the water. The content of oxygen decrease. Reduced oxygen content kills aquatic animals and reduces the rate of decomposition of organic matter which, therefore, accumulates. (vii) Sewage Organic wastes are contributed as domestic and commercial sewage by food processing plants, dairy, farms, piggeries, poultry farms, slaughter houses, breweries, tanneries, etc. Animal excreta discharged into fields or dumped in to pits reaches water bodies through run off and leaching, particularly during the rainy season and cause water pollution. Ways to reduce water pollution are (i) If sewage and garbage generated by homes and industries is treated properly before discharging into water sources, it will reduce water pollution and cause less harm to the aquatic life. (ii) If hot water generated by the industries is collected at common place, allowed to cool and then discharged in water-bodies, it will not affect the breeding capacity of aquatic organisms. (iii) If commercial areas, factories and industries are shifted to the isolated area far away from residential areas, it can reduce the effect of air pollution on people.