12. Study the following statements about ozone:
(a) It is essential for breathing of living organisms.
(b) It is used to disinfect water.
(c) It absorbs ultraviolet rays.
(d) Its proportion in air is about 3%.
Which of these statements are correct?
(i) (a), (b) and (c)
(ii) (b) and (c)
(iii) (a) and (d)
(iv) All four
Only statements (b) and (c) are correct. Hence the correct option is (ii).
View Full Answer(1)11. Here is a crossword puzzle: Good luck!
Across
3. Liquid waste products
4. Solid waste extracted in sewage treatment
6. A word related to hygiene
8. The waste matter discharged from the human body
Down
1. Used water
2. A pipe carrying sewage
5. Micro-organisms which cause cholera
7. A chemical to disinfect water
Across
3. SEWAGE
4. SLUDGE
6. SANITATION
8. EXCRETA
Down
1. WASTEWATER
2. SEWER
5. BACTERIA
7. OZONE
10. Outline your role as an active citizen concerning sanitation.
As an active citizen, we should ensure that proper sanitation facilities are available in our homes and workplaces, should make people aware of the necessity of sanitation and should not throw garbage in the open as it will block the drains and restrict the flow of the sewage. We can make sure that our surroundings and the environment are clean and that proper decomposition of waste products is done.
View Full Answer(1)9. Explain the relationship between sanitation and disease.
Explain the relationship between sanitation and disease
View Full Answer(2)Study 40% syllabus and score up to 100% marks in JEE
8. Explain the function of bar screens in a wastewater treatment plant.
Bar screens are used to filter large-sized solid waste like plastic, cans, wood etc from the wastewater.
View Full Answer(1)7. Name two chemicals used to disinfect water.
Two chemicals used to disinfect water are Chlorine and Ozone.
Chlorine: A common disinfectant that kills microorganisms by dehydrating them. Chlorine compounds are available as commercial products.
Ozone: Used in the pharmaceutical industry.
6. Untreated human excreta is a health hazard. Explain.
Untreated human excreta is harmful for us by these ways:-
5. What is sludge? Explain how it is treated.
Sludge is the solid waste which has settled at the bottom of settling tanks during the process of wastewater treatment. It is treated by decomposition by anaerobic bacteria. This activated sludge further can be used as manure.
View Full Answer(1)4. Describe the steps involved in getting clarified water from wastewater.
The treatment of wastewater includes the following steps:
(i) First, the physical waste like plastic, rags, pebbles, wood etc is removed by passing the water through a bar screen.
(ii) Then water is sent into a sand removal tank to remove sand, pebbles, grit etc. through the process of sedimentation.
(iii) Then the rest of the solid waste is allowed to settle at the bottom of a large settling tank. This waste deposited at the bottom is called sludge and is removed through a scraper.
(iv) The harmful microorganisms in this water are killed through chlorination or UV rays.
(v) Through the aerator, air is pumped into this water so that aerobic bacteria can grow and decompose any remaining organic wastes.
(vi) This treated water is then released into the water bodies.
View Full Answer(1)3. Why should oils and fats be not released in the drain? Explain.
Oils and fats are insoluble in water. When released in the drain, it causes hardening and blocking of the sewage pipes. In an open drain, the fats block the soil pores which are required for filtering water. That is why oil and fats should not be released in the drain.
View Full Answer(1)Study 40% syllabus and score up to 100% marks in JEE
Study the following statements about ozone: (a) It is essential for breathing of living organisms.
Here is a crossword puzzle: Good luck !
Outline your role as an active citizen in relation to sanitation.
Explain the relationship between sanitation and disease.
Explain the function of bar screens in a wastewater treatment plant.
Name two chemicals used to disinfect water.
Untreated human excreta is a health hazard. Explain.
What is sludge? Explain how it is treated.
Describe the steps involved in getting clarified water from wastewater.
Why should oils and fats be not released in the drain? Explain.