7th Standard CBSE Syllabus & Materials
7th Standard CBSE
CBSE 7th Standard Science Wastewater Story Sample Question Papers Study Material - QB365
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Published on: 31/10/2025
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Questions + Answers key
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1.
Untreated human excreta is a health hazard. Explain.
2.
A man travelling in a train threw an empty packet of food on the platform. Do you think this is a proper waste disposal method? Elaborate.
3.
With reference to the treatment of polluted water at home by aeration, filtration, chlorination processes answer the following questions.
What is removed by the sand filter?
4.
With reference to the treatment of polluted water at home by aeration, filtration, chlorination processes answer the following questions.
Do chlorine have an odour?
5.
Observe the given figure and answer the following: State the functions of each part of the figure?

6.
The Eucalyptus trees are planted along sewage ponds. Give reason.
7.
Mention the use of dried sludge.
8.
Give some examples of onsite sewage disposal systems.
9.
Protozoa is causative organism of which waterborne disease?
10.
In the chemical process of water treatment water is treated with some chemicals. Describe chlorination in light of it.
11.
There are many alternative sewage disposal systems which have been developed as per needs of the community, persons, occasions, etc. Few situations/specifications of the sewage need are given below. Write the name of sewage which can be used in the following conditions.
(a) A toilet which can provide high quality manure.
(b) The toilet which is used in aeroplane during flight.
(c) A toilet which can be used in some out door gathering.
(d) A toilet used in limited water supply.
(e) A toilet which contaminates water of hand pump installed nearby.
12.
Think and suggest some ways to minimise waste and pollutants at their source, taking your home as an example.
13.
Sewage is mainly a
liquid waste
solid waste
gaseous waste
mixture of solid and gas
14.
Which of the following is/are products of wastewater treatment?
Biogas
Sludge
Both biogas and sludge
Aerator
15.
The system of a network of pipes used for taking away wastewater from homes or public buildings to the treatment plant is known as
sewers
sewerage
transport system
treatment plant
16.
One of the following type of trees are said to help in purifying wastewater quite rapidly when planted all along the sewage ponds. These are
Eucalyptus trees
Ficus trees
neem trees
peepal trees
17.
Which one of the following is a quality of wastewater?
Fowl smell
Bad taste
Dirty look
All of these
18.
Wastewater is treated in ______________ treatment plant.
19.
Stagnant water blocked in drains is good breeding place for _______________
20.
All portable toilets are ________________ toilets.
21.
The full form of WWTP is _______________
22.
Bacteria play important _______________ in sewage treatment.
23.
Poor sanitation and contaminated drinking water is the cause of a large number of diseases.
24.
Wastewater is transparent, colourless, odourless.
25.
Tuberculosis is a water-borne disease.
26.
Aerobic bacteria produces biogas sludge in the digester tank.
27.
Urea is an inorganic impurity present in sewage.
1.
Human excreta may cause water pollution and soil pollution which can lead to a lot of health related problems. Water polluted with it contains disease causing bacteria which can spread epidemics and becomes the most common route for water-borne diseases like cholera, dysentery, typhoid, etc.
2.
No, one must always put the waste in a nearby dustbin or carry it home and dispose it in dustbins there.
Waste, not properly disposed may enter into the drains and choke them. It also makes public places dirty and unhygienic.
3.
Sand filter removes tiny suspended impurities.
4.
Yes, chlorine have a peculiar odour which is not worse than wastewater.
5.
(i) River It is the source of water.
(ii) Pumping station Pump the water to collect it in reservoir.
(iii) Sedimentation tank Impurities are settle in the bottom of tank.
(iv) Sand and gravel and sand filter Remove the dirt from the water.
(v) Chlorinating tank Chlorine is mixed in water to disinfect the water and to kill the germs.
(vi) To overhead tank Purified water is stored in this tank for supply to the households for drinking.
6.
The Eucalyptus trees are planted along sewage ponds because these trees absorb all surplus wastewater rapidly and release pure water vapour into the atmosphere.
7.
It is used as manure, thus returning organic matter and nutrients to the soil.
8.
Chemical toilets, septic tanks, composting pits, etc.
9.
Dysentry.
10.
Chlorination is the process of adding chlorine (chemical) in water to make it safe for drinking.
11.
(a) Vermi-composting toilets
(b) Vacuum toilets
(c) Chemical toilets
(d) Composting toilets
(e) Septic tank toilets
12.
We can minimise waste and pollutants entering the water and create less wastewater by taking following few steps at home:
(i) By not throwing used tea leaves, solid food remains, etc., in the drain. We should throw it in the dustbin.
(ii) By not throwing chemicals like medicines, paints, insecticides, etc., in the drain as they increase the pollution load of the sewage
13.
(a)
liquid waste
14.
(c)
Both biogas and sludge
15.
(b)
sewerage
16.
(a)
Eucalyptus trees
17.
(d)
All of these
18.
( )
waste
19.
( )
insect vectors
20.
( )
chemical
21.
( )
wastewater treatment plant
22.
( )
role
23.
(a)
24.
(b)
25.
(b)
26.
(b)
27.
(b)
7th Standard CBSE Syllabus & Materials
7th Standard CBSE
CBSE 7th Standard Science Electric Current and Effects Sample Question Papers Study Material - QB365 Set A
NEW7th Standard CBSE
CBSE 7th Standard Science Motion and Time Sample Question Papers Study Material - QB365 Set D
NEW7th Standard CBSE
CBSE 7th Standard Science Motion and Time Sample Question Papers Study Material - QB365 Set C
NEW7th Standard CBSE
CBSE 7th Standard Science Motion and Time Sample Question Papers Study Material - QB365 Set B
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