Answer:

1. Answer : (a) Foul smell

Explanation: Foul smell is a quality of waste water.

2. Answer : (a) water for life

Explanation: Period 2005-2015 is being celebrated as the international decade for action on water for life.

3. Answer : (b) 50-60 m

Explanation: Manholes are located at every 50-60 m in the sewerage, at the junction of two or more sewers and at points where there is a change in direction.

4.  Answer : (b) aerobic bacteria

Explanation: Sludge is collected by a scrapper. It is transferred to a separate tank where it is decomposed by the anaerobic bacteria. The biogas produced in the process can be used as fuel.

5. Answer : (a) Earthworm

Explanation: In Vermi-processing toilets, humans excreta is treated by earthworms. In this process, human excreta is completely converted to vermi cakes by earthworms.

6. Answer : (a) liquid waste

Explanation: Sewage is defined as waste water due to which it is a liquid waste.

7. Answer : (c) Both Biogas and sludge

Explanation: Biogas and sludge are the products of wastewater treatment.

8. Answer : (d) All of these

Explanation: A Open drain systems are a breeding place for different flies, mosquitoes, and other disease causing organisms. The waste drainage system should be closed.

9. Answer : (a) Sewers

Explanation:The pipes through which the wastewater flows into the sewage are known as sewers, whereas, wastewater is collected into the sewage from homes, industries and hospitals. Hence, sewers is not a source of wastewater.

10. Answer : (d) Water coming out of a laundry

Explanation: This water is called as wastewater. Water coming out of the damaged tap, water coming out of shower and water flowing in a river are not dirty hence water coming out of a laundry.

11. Answer : (b) wastewater

Explanation: Wastewater is used water that has been affected by domestic, industrial and commercial use. Wastewater effluents are released to a variety of environments, such as lakes, ponds, streams, rivers, estuaries and oceans. Wastewater also includes storm runoff, as harmful substances wash off roads, parking lots and rooftops

12. Answer : (b) health hazard

Explanation: Untreated human excreta is a health hazard. It contains various disease-causing microorganisms. When this contaminated water is used for drinking, it causes diseases such as cholera, typhoid, hepatitis, dysentery, etc, which may even lead to death.

13. Answer : (d) Cow dung

Explanation: The gas produced from cow dung or other organic material is called biogas. Biogas is a gas produced from the fermentation process of organic materials. 

14. Answer : (d) sand and grit removal

Explanation: Grit removal is the process used to remove sand, silt and grit from water. Grit (and sand) removal is often found in the headworks of wastewater treatment plants.

15. Answer : (b) biogas plant

Explanation: In many villages, human excreta from the toilet seats in the homes flows directly into biogas plant through covered drains . The biogas produced is used as a fuel.

16. Answer : (a) Municipal corporation

Explanation: The urban poor suffer disproportionately from the lack of adequate sanitation. .Studies have shown that improved health outcomes are dependent on neighbours' access to adequate sanitation.

17. Answer : (a) cleaning of water

Explanation: Cleaning of water is a process of removing pollutants before it enters a water body or is reused. This process of wastewater treatment is commonly known as Sewage Treatment.

18. Answer : (c) energy

Explanation: Biogas is a mixture of gases, primarily consisting of methane and carbon dioxide, produced from raw materials such as agricultural waste, manure, municipal waste, plant material, sewage, green waste and food waste. It is a renewable energy source.

19. Answer : (c) Phosphates

Explanation: Phosphate or phosphorus is an inorganic component and hence, it is considered an inorganic impurity in sewage.Urea, pesticides, and vegetable waste all are organic.

20. Answer : (a) aerobic bacteria

Explanation: Aerator. Air is pumped into the clarified water to help aerobic bacteria to grow. Bacteria consume human waste, food waste, soaps and other unwanted matter still remaining in clarified water.

21. Answer : (b) Sewage

Explanation: Sewage is liquid waste containing dissolved impurities called as contaminants. Sewage comprises dissolved and suspended impurities.

22. Answer : (b) Waste Water Treatment Plant

Explanation: A wastewater treatment plant is a facility in which a combination of various processes (e.g., physical, chemical and biological) are used to treat industrial wastewater and remove pollutants.

23. Answer : (c) They harden and block the pipe 

Explanation: Cooking oil should not be thrown down the drain because it can block the drainage pipes. The fats clog the soil pores which reduces its effectiveness in filtering water and therefore blocks the drain pipes.

24. Answer : (d) Cholera

Explanation: Cholera, like other waterborne diseases, can spread if food and, in particular, water become contaminated with the stools of an infected person. 

25. Answer : (c) Organic

Explanation: It defines biodegradable waste as “any waste that is capable of undergoing anaerobic or aerobic decomposition, such as food and garden waste, and paper and cardboard.”

Click here for Practice MCQ Questions for Wastewater Story Class 7

Class 7 Science MCQ Questions of Wastewater Story with Answers helps Students to have more grounded fundamentals and covers all the ideas of Science. Access the MCQ Questions with Answers of Class 7 Science and get a decent grasp on the ideas along these lines to endeavor the exams with certainty. These MCQ Questions are chosen upheld by the freshest exam pattern as reported by CBSE. Each question has four alternatives followed by the right answers. 

MCQ Questions for Class 7 Science given here center more around information building and help the students to have a more profound understanding of the concept. This might help you to understand and check your insight about the parts. You can check detailed solutions of MCQ Questions for class 7 Science. Access the MCQ Questions with Answers of Class 7 Science and get a decent hold on the ideas consequently endeavor the exam with confidence.

Practice MCQ Questions for Class 7 Science

1. Which one of the following is a quality of wastewater?

(a) Foul smell
(b) Sweet taste
(c) Sewage
(d) None of these

2. Period 2005-2015 is being celebrated as the international decade for action on

(a) water for life
(b) education for all
(c) global war
(d) terrorism

3. In sewerage manholes are located at every

(a) 20-25 m
(b) 50-60 m
(c) 90-100 m
(d) 100-110 m

4.  Sludge in separate tanks is decomposed to get biogas by

(a) yeasts
(b) aerobic bacteria
(c) anaerobic bacteria
(d) none of these

5. Which one of the following is used in vermi-processing toilet?

(a) Earthworm
(b) Cockroach
(c) Both of these
(d) None of these

6. Sewage is mainly a

(a) liquid waste
(b) Solid waste
(c) gaseous waste
(d) Mixture of solid and gas

7. Which of the following is/are products of wastewater treatment?

(a) Biogas
(b) Sludge
(c) Both Biogas and sludge
(d) Aerator

8. Open drain system is a breeding place for which of the following:

(a) Files
(b) Mosquitoes
(c) Organisms which cause diseases
(d) All of these

9. Which of the following is not a source of waste water?

(a) Sewers
(b) Homes
(c) Industries
(d) Hospital

10. Which of the following is wastewater?

(a) Water trickling from a damaged tap
(b) Water coming out of a shower
(c) Water flowing in a river
(d) Water coming out of a laundry

11. Water that is not fit for use is called

(a) clean water
(b) wastewater
(c) both (a) and (b)
(d) none of these

12. Untreated human excreta is a:

(a) waste water
(b) health hazard
(c) manure
(d) none of these

13. Which one is not a of household garbage

(a) Vegetable peels
(b) Dal packets
(c) Crockery pieces
(d) Cow dung

14. Which process removes the solids like foeces and other substances from the waste water:

(a) chlorination
(b) decomposition
(c) evaporation
(d) sand and grit removal

15. Excreta from the toilet seats flow through covered drains into a chemicals:

(a) chemicals
(b) biogas plant
(c) vermi-processing toilets
(d) none of these

16. Sanitation in the cities is the function of

(a) Municipal corporation
(b) Non-government organisation
(c) Individual person
(d) Societies of locality

17. The process of removing pollutants in water before it enter a water body is called

(a) cleaning of water
(b) refining
(c) filtering of water
(d) none of these

18.The biogas product is used as a source of:

(a) rains
(b) oils
(c) energy
(d) all of these

19. Which of the following is a part of inorganic impurities of the sewage?

(a) Pesticides
(b) Urea
(c) Phosphates
(d) Vegetable waste

20. What helps to clean the clarified water:

(a) aerobic bacteria
(b) anaerobic bacteria
(c) both (a) and (b)
(d) none of these

21. Liquid waste consisting of suspended impurities is called

(a) Contaminant
(b) Sewage 
(c) Aeration 
(d) Chlorination

22. WWTP stands for 

(a) Waste Water Therapy Plant
(b) Waste Water Treatment Plant
(c) Waste Water Travel Plant
(d) Waste Water Tremendous Plant

23. Cooking oil and fats should not be thrown down the drain because

(a) They flow through the drain freely
(b) It allows the particles to get filtered
(c) They harden and block the pipe 
(d) They break the pipe

24. Water borne disease is

(a) Diabetes 
(b) Cancer
(c) Appendicitis
(d) Cholera

25. Biodegradable wastes are generally

(a) Blended
(b) Synthetic
(c) Organic
(d) Inorganic