Question

What is water pollution? List its causes and methods of prevention.

Answer 1

Water pollution

• The contamination of water bodies with unwanted substances which have a harmful effect on both living and non-living organisms is known as water pollution.
• The unwanted substance which contaminates water thereby causing water pollution is known as pollutants.
• Presence of pollutants makes the water unfit for drinking and has a foul-smell and bad taste.
• Pesticides, insecticides, fertilizers, soap, and oil spill are the pollutants of water pollution.

Types of water pollution

Thermal water pollution:

• It is the degradation in the quality of water due to some process that changes the temperature of the water.
• It arises due to the use of water as coolant in power plants and industry.
• Change in temperature of the water decreased the dissolved $\mathrm{Oxygen}\left({\mathrm{O}}_2\right)$ content and thereby affect aquatic life

Chemical water pollution:

• Pollution of water bodies due to the accumulation of chemicals is known as chemical water pollution.
• The major source of chemical water pollution are industrial sewage, agricultural waste, and oil spill.

(A) Industrial sewage

• Industrial sewage contains many chemicals in the form of byproducts as well as solvents.
• These are directly released into the water bodies without any treatment.
• Consequently these poisonous chemicals slow down the growth of aquatic life and kill them.

(B) Agricultural waste

• In the era of modern agriculture, farmers use large quantities of pesticides, insecticides, and fertilizers than what is actually required by the plants.
• The excessive use of this chemical in the agricultural field find its way to water bodies, and they start accumulating in the fishes.
• As a results bird and human beings may be poisoned by consuming this fish.

(C) Oilspill

• The accidental leakage of ships carrying heavy oil tankers polluted the seawater by the oil spill.
• It is one of the major causes of water pollution that affects the life of both marine plants and animals.

Method of prevention

• Discourage the excessive use of pesticides, insecticides, and fertilizers in agriculture.
• Domestic and industrial sewage, should be treated in an appropriate sewage treatment plant to remove the toxic substances before discharging directly into the water bodies.
• Taking bath and washing cloth on the banks of water bodies need to be controlled.
• Strictly follow the pollution control rules enforced by the government.
• Provide awareness to the public about the harmful effects of water pollution.