Question

Explain the causes of water pollution.

Answer 1

Water Pollution:

The undesirable changes in the physical, chemical and biological properties of water due to the contamination by pollutants that causes harm to the environment and living organisms is termed water pollution.

Causes of water pollution:

The major causes of water pollution include sewage waste, household detergents, industrial waste, heavy metals, nuclear reactors, and radioactive wastes.

1. Sewage: It constitutes the discharge of carbonic materials and biological materials in the waterbody. The carbonic materials increase leads to an increase in the number of decomposers such as bacteria and fungi, which reduces the amount of dissolved oxygen in the water and increases the biological oxygen demand (BOD) of water. The higher value of BOD indicates water pollution.
2. Industrial waste: Industrial wastes are the major cause of water pollution as the industries discharge toxic and harmful chemicals into the canals and rivers etc. It is comprised of inert suspended particles such as dust and coal, toxins such as acid, base, phenols, cyanides, mercury, zinc, etc., and inorganic materials such as salts of ferrous and sulfides.
3. Detergents: The detergents used to clean utensils and wash clothes include the compounds of nitrate, ammonium, phosphate, and alkylbenzene sulphonate. For example, Alkylbenzene sulphonates a compound found in detergents are not degraded easily, so if their concentration in water bodies increases, it can cause harm to aquatic organisms.
4. Heavy metals: The presence of heavy metals such as lead, mercury, copper, cadmium, and arsenic causes water pollution. The presence of these heavy metals in water becomes a reason for causing diseases.