Question

into water bodies such as streams
• There are three ways of treating sludge, namely, incinerating, dewatering, and composting.
• Water pollution can be caused as a result of the discharge of untreated or partly treated
sewage in water bodies, sometimes due to improper sewage handling processes of
municipal bodies.
Leakages in several places in the main water supply line cause drinking water to get mixed
with sewage. Due to this, the water supply gets contaminated.
• People consuming contaminated water may suffer from diseases like gastroenteritis,
dysentery, and typhoid.
Exercises
LET'S UNDERSTAND
1.
Objective type questions
A. Fill in the blanks with the correct words.
✓
1. An excessive growth of
(plants/algae) causes eutrophication.
2.
(Sewer/Onsite disposal) system is a channel system of pipelines
used to carry sewage.
3. Air is blown into the sewage in
(sedimentation/aeration) tanks.
4.
(LPG/Biogas) is produced by the action of bacteria on the organic
matter of the sludge.
5.
(Earthworms/Ants) are used to convert human excreta into compost
in vermi-composting toilets.​

Answer 1

1.An excessive growth of algae causes eutrophication, also known as algal bloom

2. Sewer system is a channel system of pipelines.

3.Air blown into the sewage in aeration tank .

4.Biogas is produced by the action of bacteria on the organic matter of the sludge.

5.Earthworms are used to convert human excreta into compost .