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Water Pollutants

Water PollutionWater Pollution

Transcript

  • 0:3Ganga. It is the most polluted river in India.
  • 0:7In fact according to a recent study by
  • 0:11World Wide Fund for nature, Ganga is
  • 0:14considered to be one of the 10 most
  • 0:16endangered rivers in the world. But it's
  • 0:20not only Ganga that is polluted. There
  • 0:23are many other water bodies that have
  • 0:25been polluted because of water pollutants.
  • 0:27Let us study about these water
  • 0:29pollutants in this lesson. The main water
  • 0:32pollutants are the harmful chemicals
  • 0:35that are discharged by industries
  • 0:37directly into the rivers and streams.
  • 0:39These industries include oil refineries,
  • 0:42paper factories, textile and sugar mills,
  • 0:46chemical factories etc. All of these
  • 0:50cause chemical contamination of water.
  • 0:53Industries release chemicals like
  • 0:55arsenic, leads and fluorides into the
  • 0:58water bodies. All these chemicals cause
  • 1:2toxicity in plants and animals. The
  • 1:5impure water also affects the soil. It
  • 1:7changes the acidity of the soil. Due to
  • 1:10which the growth of worms, plants,
  • 1:14everything is affected. But there are
  • 1:17regulations to prevent this. Industries
  • 1:20are supposed to treat the waste produced,
  • 1:22to reduce the toxicity before
  • 1:24discharging it into the water bodies.
  • 1:27But often the rules are not followed.
  • 1:30Other pollutants are weedicides and
  • 1:33pesticides. These are very important for
  • 1:36production of crops but when they are
  • 1:39washed away from the field, they dissolve
  • 1:41in water bodies and pollute the
  • 1:42water. They sometimes also seep into the
  • 1:46ground and pollute the groundwater. These
  • 1:48chemicals which get washed away from the
  • 1:51fields, also affect water bodies like
  • 1:53ponds.
  • 1:54You must have seen a pond which looks
  • 1:57green from a distance that is because
  • 1:59growth of a lot of algae in it.
  • 2:3Excessive quantity of chemicals act as
  • 2:6nutrients to these algae. When these
  • 2:9algae die, they serve as a food for
  • 2:12decomposers like bacteria. A lot of
  • 2:15oxygen from the
  • 2:16water is used up in this process. This
  • 2:19leads to decrease in oxygen level in the
  • 2:22water that can kill even the aquatic
  • 2:25organisms. The next water pollutant that
  • 2:28we will be talking about is sewage.
  • 2:31Sewage contains food waste, detergents,
  • 2:34microorganisms etc. So it has to be
  • 2:38treated before it is disposed.
  • 2:41But sometimes untreated sewage is thrown
  • 2:43directly into the rivers.
  • 2:45This causes water to contaminate and
  • 2:48such water which is contaminated by
  • 2:51sewage may contain bacteria, fungi,
  • 2:55parasites, viruses which cause diseases
  • 2:59like typhoid, cholera and jaundice. Untreated
  • 3:3sewage is sometimes disposed in soil which
  • 3:6leads to the pollution of groundwater.
  • 3:8Other pollutants are bacteria produced
  • 3:13by faeces of mammals. When people start
  • 3:16defaecating in the river, these bacterias
  • 3:19get mixed with water and contaminate the
  • 3:22water and if we consume such water we
  • 3:25might get infections. Even hot water can
  • 3:29be a pollutant. Usually this hot water is
  • 3:32disposed in the river by industries and
  • 3:35power plants. It raises the temperature
  • 3:37of the water in the water body which
  • 3:40leads to adverse effects on aquatic
  • 3:43animals and plants living in it.