CAUSES,EFFECTS & CONTROL MEASURES OF WATER POLUTION

 

Introduction: Water is the essential element that makes life on earth possible. Without water there would be no life. We usually take water for granted. It flows from our taps when they are turned on. Most of us are able to bathe when we want to, swim when we choose and water our gardens. Like good health we ignore water when we have it.

Definition:

“Water pollution is defined as alteration in physical, chemical and biological properties of water as well as contamination with any foreign substances which would cause harmful effects or otherwise decrease the utility of water”

Causes of Water pollution:

1.      Domestic sewage: This contains different pollutants like salts, soaps, detergents; organic compound etc. the disposal of sewage into river and lakes causes the pollution.

2.      Industrial effluents: Water gets polluted by the industrial effluents, which contain many harmful compounds like acids, bases, dyes, detergents, nitrate, cyanide etc.

3.      Agricultural wastes:  fertilizers, pesticides, farm wastes, manure slurry cause heavy pollution to water sources. Some of these are washed away through rainfall, irrigation and drainage into water bodies.

4.      Oil transportation: petroleum products are transported from one country to another country by oceans or seas. Oil spill occurs during the transportation, which result pollution of water.

5.      Food chains: The pollutant present in water consumed by fish and other aquatic animals, again consumed by other animals and human beings. The concentration of these pollutants goes on increasing by the time they reach human beings. The increasing of concentration of pollutants from lower animal to higher animals is called as “food chains”. These pollutants may cause different diseases.

Effects of Water pollution:

1.      On living organisms:

i)                 Polluted water causes contaminated diseases like typhoid, jaundice, cholera, diarrhea skin diseases etc.

ii)               Water containing fluoride causes fluorosis.

iii)             The pesticides and insecticides reach human body through food chains and affect the nervous system.

iv)              Oil pollutants kill birds, fishes and other aquatic organisms.

v)               Polluted water affects the plant metabolism and disturbs the ecosystem.

2.       On Non-living things:

i)                 Polluted water reduces soil fertility by killing bacteria and soil micro-organism and increasing alkalinity.

ii)               Pollutes water corrodes ships, piping, pumps and machinery parts.

iii)             Polluted water reduces the strength of concrete structures.

Controlling methods of Water pollution:

1.      Treatment of drainage water: The drainage system should be in a proper way and the drainage water should be treated to remove the pollutants.

2.      Treatment of industrial Effluents: The industrial effluents contain various toxic chemical depending upon the nature of industry. These must be treated by physical, chemical and biological method to remove the pollutants.

3.      Control over unhygienic practices: people should be educated in favour of necessity of effective water pollution control.

4.      Stabilization of ecosystem: this would involve reduction in waste input, harvesting and removal of biomass, trapping of nutrients, aeration and fish management.

5.      Removal of pollutants: techniques like absorption, ion-exchange, electrolysis, reverse-osmosis can be used for the removal of chemical and radioactive water pollutants.