07-11-2012, 05:30 PM
WATER POLLUTION
WATER POLLUT.pptx (Size: 2.11 MB / Downloads: 111)
Definition
It can be defined as alteration in physical, chemical or biological characteristics of water making it unsuitable for designated use in its natural state.
Water pollution occurs when pollutants are discharged directly or indirectly into water bodies without adequate treatment to remove harmful compounds.
Where does water pollution come from?
Point sources discharge pollutants at specific locations through pipelines or sewers into the surface water. Examples are: factories, sewage treatment plants, underground mines, oil wells, oil tankers and agriculture.
Nonpoint sources are sources that cannot be traced to a single site of discharge. Examples are: acid deposition from the air, traffic, pollutants that are spread through rivers and pollutants that enter the water through groundwater.
Some facts and figures
It accounts for the deaths of more than 15,000 people daily.
An estimated 700 million Indians have no access to a proper toilet, and 1,000 Indian children die of diarrheal sickness every day.
Some 90% of China’s cities suffer from some degree of water pollution, and nearly 500 million people lack access to safe drinking water.