Download WATER POLLUTION CLASS 8 What are the factors responsible for

WATER POLLUTION CLASS 8
( AIR & WATER POLLUTION PART -2)
Water Pollutants The substances that pollute water are called water pollutants.
Eg:- sewage, toxic chemicals, silt, etc.,
Water Pollution Any change in the physical, chemical or biological characteristics of the
water which makes unfit for use for any organism is called Water pollution.
RIVER GANGA;- famous rivers of India sustains most of the northern, central and eastern
Indian population.
STUDY OF WWF ON RIVER GANGA World Wide Fund for Nature (WWF)
Ganga is one of the ten most endangered rivers in the world.
The river is “dead” at many places.
REASON ;- because the towns and cities, through which the river flows,
throw large quantities of garbage, untreated sewage, dead bodies, and many
other harmful things, directly into the river.
Ganga Action Plan A plan to save the river launched in 1985.
aimed to reduce the pollution levels in the river.
.The Real Situation The Ganga at Kanpur in Uttar Pradesh (U.P.),
1. Ganga is most polluted
2. Kanpur is one of the most populated town
3. People do bathing, washing clothes and defecating in the rive
4. People throw garbage, flowers, idols of gods and goddesses and
5. non-biodegradable polythene bags into the river.
the flow of the river is very slow.
. 6. The industrial units (fertiliser, detergent, leather and
paint industries) discharge toxic chemical wastes into the river.
What are the factors responsible for pollution of the river ?
1. chemical contamination of water Many industries (oil refineries,
paper factories, textile and sugar mills and chemical factories )
discharge harmful chemicals into rivers and streams,
. 2. The chemicals released include arsenic, lead and fluorides which lead
to toxicity in plants and animals.
3 Industries do not treat the waste water / the rules are not followed.
4 The soil is also affected by impure water, causing changes in
acidity, growth of worms, etc.
5. Over use of Pesticides and Weedicides dissolve in water and
are washed into water bodies from the fields. They seep into the
ground to pollute ground water.
6. Algal Blooming is caused by excessive quantities of
chemicals which get washed from the fields. These act as nutrients
for algae to grow. Once these algae die, they serve as food for
decomposers like bacteria. A lot of oxygen in the water body gets
used up. This results in a decrease in the oxygen level which may
kill aquatic organisms.
7. Throwing untreated wastage;- untreated sewage is thrown
directly into rivers. It contains food wastes, detergents, microorganisms.
Water contaminated with sewage may contain bacteria, viruses, fungi
and parasites which cause diseases like cholera, typhoid and jaundice.
8. Presence of bacteria ;-The bacteria present in the faeces of mammals are
indicators of the quality of water. If water has these bacteria, it means
that it has been contaminated by fecal matter.
water from power plants and industries. It is released
into the rivers. It raises the temperature of the waterbody, adversely
affecting the animals and plants living in it.
9. Hot
POTABLE WATER Water which is suitable for drinking is called potable water.
Method of making water safe for drinking ;1. Filtering to remove impurities. ( using candle type filter)
2. Boiling kills the germs present in the water.
3. Chlorination by adding chlorine tablets or bleaching powder to the water to kill germs.
(No overuse of chlorine tablets than specified)
What is to be done to reduce water pollution.
1.strictly implement law to preent water pollution.
.2. Make Water treatment in all industrial areas
4. save water and do not waste it.
4 Reduce, reuse and recycle should be followed.