Tag: wastewater treatment - need and methods

Questions Related to wastewater treatment - need and methods

Primary treatment reduces solids, ranges from

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

  1. 20-60%

  2. 10-50%

  3. 20-70%

  4. 40-60%

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Correct Option: D

Which of the following are correctly matched ? 
1. Arsenic poisoning - Black-foot disease
2. Secondary effluent treatment - Biological process 
3. Pyrolysis - Waste disposal
4. Tubifex - Water pollution indicator 
5. Biomagnification - Degradable pollutants 

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

  1. 1, 2, 3 and 5

  2. 1, 3, 4 and 5

  3. 2, 3, 4 and 5

  4. 1, 2, 4 and 5

  5. 1, 2, 3 and 4

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Correct Option: E
Explanation:

Biomagnification refers to increase in concentration of the toxicant at successive trophic levels. This happens because a toxic substance accumulated by an organism cannot be metabolised or excreted, and is thus passed on to the next higher trophic level. This phenomenon is well known for mercury and DDT. 

What involved in wastewater final treatment?

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

  1. BOD

  2. Chlorination

  3. Sedimentation

  4. All of above

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Correct Option: B

Waste water contains algae, fungi, bacteria and

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

  1. Crocodiles

  2. Snakes

  3. Rotifers

  4. Tigers

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Correct Option: C

During sewage treatment the microorganisms participate under which step?

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

  1. Primary

  2. Secondary

  3. Teritiary

  4. None of the above

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Correct Option: B
Explanation:

Sewage treatment generally involves three stages, called primary, secondary and tertiary treatment. 

Primary treatment consists of temporarily holding the sewage in a quiescent basin where heavy solids can settle to the bottom while oil, grease and lighter solids float to the surface. 
Secondary treatment removes dissolved and suspended biological matter. Secondary treatment is typically performed by indigenous, water-borne micro-organisms in a managed habitat. Secondary treatment may require a separation process to remove the micro-organisms from the treated water prior to discharge or tertiary treatment. 
Tertiary treatment allows rejection into a highly sensitive or fragile ecosystem like estuaries, low-flow rivers, coral reefs etc. 

The domestic sewage in large cities

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

  1. Has a high BOD level, as site containes both aerobic and anaerobic bacteria.

  2. Is processed by aerobic and then anaerobic bacteria in the secondary treatment in the Sewage Treatment Plants (STPs).

  3. When treated in STPs does not really require the aeration step as the sewage contains adequate oxygen.

  4. Has very high amounts of suspended solids and dissolved salts.

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Correct Option: B
Explanation:
Secondary (biological) treatment is the method to remove the dissolved organic matter that escapes primary treatment. This is achieved by microbes consuming the organic matter as food, and converting it to carbon dioxide, water, and energy for their own growth and reproduction. The biological process is then followed by additional settling tanks to remove more of the suspended solids. In this method, waste water first treated with microbes aerobically and anaerobically in anaerobic digester tank.

Sewage water is purified for recycling by the action of 

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

  1. Light

  2. Micro-organisms

  3. Aquatic plants

  4. Fishes

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Correct Option: B
Explanation:

Domestic sewage primarily contains biodegradable organic matter, which readily decomposes by bacteria and other micro-organisms, which can multiply using these organic substances as substrates and hence utilise some of the components of sewage. It is possible to estimate the amount of biodegradable organic matter in sewage water by measuring biochemical oxygen demand (BOD).  

Microorganisms involved in biodegradation of organic matter in the receiving water body consume a lot of oxygen, and as a result there is a sharp decline in dissolved oxygen downstream from the point of sewage discharge. This causes mortality of fish and other aquatic creatures. 

Which is correctly matched?
1. Arsenic poisoning- Black foot disease.
2. Secondary Effluent treatment- Biological process.
3. Pyrolysis- Solid soil waste disposal
4. Tubifex- Water pollution indicator
5. Biomagnification- Degradable pollutants

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

  1. 1, 2, 3, 5

  2. 1, 3, 4, 5

  3. 2, 3, 4, 5

  4. 1, 2, 3, 4

Show answer
Correct Option: D
Explanation:

Biomagnification refers to increase in concentration of the toxicant at successive trophic levels. This happens because a toxic substance accumulated by an organism cannot be metabolised or excreted (non degradable), and is thus passed on to the next higher trophic level. This phenomenon is well known for mercury and DDT. Biological magnification often refers to the process whereby certain substances such as pesticides or heavy metals move up the food chain, work their way into rivers or lakes, and are eaten by aquatic organisms such as fish, which in turn are eaten by large birds, animals or humans. The substances become concentrated in tissues or internal organs as they move up the chain.

Therefore, the correct answer is option D.

A sewage treatment process in which a portion of the decomposer bacteria present in the waste is recycled into the beginning of the process, is called as

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

  1. Primary treatment

  2. Tertiary treatment

  3. Activated sludge treatment

  4. Cyclic treatment

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Correct Option: C
Explanation:

The activated sludge process is a process for treating sewage and industrial wastewaters using air and a biological floc composed of bacteria and protozoa. Activated sludge refers to a mass of microorganisms cultivated in the treatment process to break down organic matter into carbon dioxide, water, and other inorganic compounds. 

The activated sludge process has three basic components: 
1) A reactor in which the microorganisms are kept in suspension, aerated, and in contact with the waste they are treating,
2) Liquid-solid separation and 
3) A sludge recycling system for returning activated sludge back to the beginning of the process. 
Therefore, the correct answer is option C.

A natural disaster caused due to insufficient water for agriculture is called

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

  1. flood

  2. draught

  3. famine

  4. forest fire

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Correct Option: C