Water pollution is the contamination of the bodies of water .Water pollution takes place when pollutants are discharged directly or indirectly into bodies of water without adequate treatment to remove harmful compounds. It is the second most important environmental issue after air pollution. Water pollution is able to affect all the huge water bodies of the world such as lakes, rivers, oceans and groundwater .
Types of Water Pollution
Toxic Substance -- A toxic substance is a chemical pollutant that is not a natural substance in aquatic ecosystems. The greatest toxic pollution contributors are pesticides , herbicides and industrial compounds.
Organic Substance -- Organic pollution takes place when an excess of organic matter gets into the water. When organic matter starts increasing in a pond, the number of decomposers will rise . These decomposers grow quickly and use a lot of oxygen during their growth. This leads to the decrease of oxygen as the decomposition process occurs. Insufficient oxygen will kill the aquatic organisms. As the aquatic organisms die, they are broken down by decomposers which then leads to more depletion of the levels of oxygen .
A type of organic pollution can take place when inorganic pollutants accumulate in aquatic ecosystems. The enormous decay of this plant matter will decrease the oxygen level. The process of rapid growth of plants followed by increased decomposers’ activity and a depletion of the level of oxygen is called eutrophication.
Thermal Pollution -- Thermal pollution can take place when water functions as a coolant near a industrial plant and then is returned to the aquatic environment at a higher temperature than it’s original temperature . Thermal pollution can cause a decrease in the dissolved oxygen level in the water while causing an increase in the biological demand of oxygen for aquatic organisms.
Ecological Pollution -- Ecological pollution occurs when chemical pollution, organic pollution or thermal pollution are occurring by nature rather than by activities of human . An example of ecologically caused pollution is an increased rate of siltation of a waterway after a landslide which would increase the sediments in runoff water. Major geological events such as a volcano eruption could also be the cause of ecological pollution. [1]
