Tag: personal and public cleanliness

Questions Related to personal and public cleanliness

Study the following statements about ozone:
(a) It is essential for the breathing of living organisms.
(b) It is used to disinfect water.
(c) It absorbs ultraviolet rays.
(d) Its proportion of air is about 3%. Which of these statements are correct?

biology wastewater story personal and public cleanliness who will do this? basics of water pollution

  1. (a), (b) and (c) 

  2. (b) and (c)

  3. (a) and (d)

  4. All four 

Show answer
Correct Option: B
Explanation:
  • Ozone, or trioxygen, is an inorganic molecule with the chemical formula $O _3$. It is a pale blue gas with a distinctively pungent smell.
  • Oxygen is essential for the breathing of living organisms. Hence statement (a) is incorrect.
  • Ozone is a powerful oxidant, stronger than chlorine. Ozone is used to disinfect, deodorize, decolourize and decompose organic substances in water. Hence Statement (b) is correct.
  • The ozone layer or ozone shield is a region of Earth's stratosphere that absorbs most of the Sun's ultraviolet radiation. Hence statement (c) is correct.
  • The proportion of ozone in the air is 0.000004%. Hence Statement (d) Is incorrect.
  • So, the correct answer is '(b) and (c)'.

Biogas is produced due to the .................. fermentation of the slurry of animals dung.

biology wastewater story personal and public cleanliness who will do this? basics of water pollution

  1. Pesticides

  2. Anaerobic

  3. Coal

  4. Methane

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Correct Option: B
Explanation:

Biogas is produced due to the anaerobic fermentation of the slurry of animals dung.
Microbial conversion of organic matter to methane has become attractive as a method of waste treatment and resource recovery. This process is anaerobic and is carried out by action of various groups of anaerobic bacteria.
Three basic points about this process are that most of the important bacteria involved in biogas production process are anaerobes and slow growing, a greater degree of metabolic specialization is observed in these anaerobic microorganisms and that most of the free energy present in the substrate is found in the terminal product methane. Since less energy is available for the growth of organism, less microbial biomass is produced and, consequently, disposal of sludge after the digestion may not be a major problem.

An example of water-borne disease is 

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  1. Scabies

  2. Influenza

  3. Trachoma

  4. Typhoid

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Correct Option: D

Biological control during sewage treatment is observed in 

biology wastewater story personal and public cleanliness who will do this? basics of water pollution

  1. Aerating tanks

  2. Settling tanks

  3. Anaerobic sludge digesters

  4. Primary treatment

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Correct Option: A
Explanation:

During secondary treatment, the sewage water is aerated and added with microorganisms like the bacteria and protozoa, these microorganisms degrade organic wastes in presence of oxygen

Sewage is mainly a

biology wastewater story personal and public cleanliness who will do this? basics of water pollution water borne disease hygiene - a key to healthy life

  1. liquid waste

  2. solid waste

  3. gaseous waste

  4. mixture of liquid waste and organic matter

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Correct Option: D

Aeration process change the odour of wastewater.

biology wastewater story personal and public cleanliness who will do this? basics of water pollution water borne disease hygiene - a key to healthy life

  1. True

  2. False

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Correct Option: B
Explanation:

Aeration is mixing of oxygen into the water. It increases the microbial growth in the water. The microbial growth acts on the organic matter and creates flocs which settle. The degradation of organic matter leads to the change in the pH of the water and production of gases like hydrogen sulfide which creates an odour.

So, the correct answer is option B.

Main sources of nitrogen compounds in waste water are proteins, amines, and

biology wastewater story personal and public cleanliness who will do this? basics of water pollution

  1. Urea

  2. Fats

  3. Calcium

  4. Phosphorous

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Correct Option: A

What are characteristics of 'domestic' wastewater?

biology wastewater story personal and public cleanliness who will do this? basics of water pollution

  1. Grey color, musty odour

  2. Blue color, odourless

  3. Green color, musty odour

  4. All of Above

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Correct Option: B

If large quantities of domestic sewage is continuously emptied into a small stream, it leads to

zoology environmental science personal and public cleanliness who will do this? basics of water pollution

  1. depletion of oxygen content in stream water

  2. depletion of nutrients in the stream water

  3. enrichment of oxygen content in stream water

  4. increase in the total amount of life in the stream water.

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Correct Option: A
Explanation:

If large quantities of domestic sewage are continuously emptied into a small stream, it leads to depletion of oxygen content in stream water as microbes that develop to degrade the organic matter shall consume the oxygen and reduces its amount.

So the correct option is 'depletion of oxygen content in stream water'

Water should pretreat before its disposal.

zoology environmental science personal and public cleanliness who will do this? basics of water pollution

  1. True

  2. False

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Correct Option: A