Tag: microbial pollution control

Questions Related to microbial pollution control

Activated sludge should have the ability to settle quickly so that it can:

zoology introduction to microbiology microbial pollution control environmental use of microorganism microbes in waste treatment and biogas

  1. be rapidly pumped back from sedimentation tank to aeration tank

  2. absorb pathogenic bacteria present in wastewater while sinking to the bottom of the settling tank

  3. be discarded and anaerobically digested

  4. absorb colloidal organic matter.

Show answer
Correct Option: A
Explanation:

The activated sludge have to settle quickly so that it can be pumped back to the aeration tank. So, the correct option is 'be rapidly pumped back from sedimentation tank to aeration tank'

In the sewage treatment, bacterial flocs are allowed to sediment in a settling tank. This sediment is called as:

zoology introduction to microbiology microbial pollution control environmental use of microorganism microbes in waste treatment and biogas

  1. inactivated sludge

  2. activated sludge

  3. primary sludge

  4. secondary sluge

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Correct Option: B
Explanation:
In the secondary treatment, the effluent is passed into a settling tank where the bacterial flocs are allowed to sediment and the sediment is called activated sludge.
So, the correct option is 'activated sludge'

The primary treatment of removal of:

zoology introduction to microbiology microbial pollution control environmental use of microorganism microbes in waste treatment and biogas

  1. dissolved impurities

  2. stable particles

  3. toxic substances

  4. harmful bacteria

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Correct Option: A
Explanation:

The primary treatment involves physical removal of particles from the sewage through filtration and sedimentation. These are removed initially by sequential filtration which removes the floating debris and then grit is removed by sedimentation. 

So, the correct option is 'Option A' .

Wastewater treatment generates a large quantity of sludge, which can be treated by:

zoology introduction to microbiology microbial pollution control environmental use of microorganism microbes in waste treatment and biogas

  1. anaerobic digesters

  2. floc

  3. chemicals

  4. oxidation pond

Show answer
Correct Option: A
Explanation:

Wastewater treatment generates a large quantity of activated sludge during secondary treatment which is used as a inoculum and a small part of it is pumped back to the large aeration tanks whereas the remaining part of that sludge is treated by anaerobic sludge digesters anaerobically. During this digestion, bacteria produces a mixture of gases called biogas. 

So, the correct option is 'Option A' .

Activated sludge should have the ability to settle quickly so that it can

zoology introduction to microbiology microbial pollution control environmental use of microorganism microbes in waste treatment and biogas

  1. Be rapidly pumped back from sedimentation tank aeration tank.

  2. Absorb pathogenic Bactria present in waste water while sinking to the bottom of the settling tank

  3. Be discarded and anaerobic ally digested

  4. Absorb colloidal organic matter

Show answer
Correct Option: A
Explanation:

Activated sludge should have the ability to settle quickly so that it can be rapidly pumped back from sedimentation tank to the aeration tank, where it can start the process of decomposition of the organic matter again. Activated sludge has filamentous bacteria that are capable of performing the aerobic digestion of organic waste is the sewage water.

Hence, the correct answer is 'Be rapidly pumped back from sedimentation tank aeration tank' 

Waste water treatment generates a large amount of sludge, which can be treated by

zoology introduction to microbiology microbial pollution control environmental use of microorganism microbes in waste treatment and biogas

  1. Anaerobic digesters

  2. Floc

  3. Chemicals

  4. Oxidation pond

Show answer
Correct Option: A
Explanation:
  • Anaerobic digestion is a collection of processes by which microorganisms break down biodegradable material in the absence of oxygen.
  •  The process is used for industrial or domestic purposes to manage waste and to produce fuels. 
  • Hence, Wastewater treatment generates a large amount of sludge, which can be treated by anaerobic digesters.
  • So, the correct answer is 'anaerobic digesters'.

Chlorine treatment

zoology introduction to microbiology microbial pollution control environmental use of microorganism microbes in waste treatment and biogas

  1. Removes all the air pollutants

  2. Disinfects water by killing germs

  3. Removes hardness of water

  4. All of the above

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Correct Option: B
Explanation:

Chlorine is a powerful disinfectant that can kill the bacteria and viruses by destabilizing the chemical bonds of the pathogens. So, it is used in purification of water.

Hence, the correct answer is 'Disinfects water by killing germs'

Which one is the most important role of microorganisms for the well being of humans?

zoology introduction to microbiology microbial pollution control environmental use of microorganism microbes in waste treatment and biogas

  1. Sewage treatment

  2. Production of methane

  3. Conversion of milk to curd

  4. Biological control of plants disease

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Correct Option: C
Explanation:

Answer is option C i.e. "Conversion of milk to curd"

Microorganisms help in the production of many food items, making medicines, keeping the environment clean, in manufacturing and in research. 
Conversion of milk to curd is the considered as an important role in the micro organism for the well being of humans. . Bacteria like Lactobacillus can be used to make curd from milk by process of fermentation.

Secondary treatment is carried out for removal of;

zoology introduction to microbiology microbial pollution control environmental use of microorganism microbes in waste treatment and biogas

  1. Suspended solids

  2. Dissolved organic matters

  3. Floating materials

  4. Solid impurities

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Correct Option: B

Sewage water is purified for reuse by the action of

zoology introduction to microbiology microbial pollution control environmental use of microorganism microbes in waste treatment and biogas

  1. Protozoans

  2. Micro-organisms

  3. Plants and light

  4. Fish

Show answer
Correct Option: B
Explanation:

Domestic sewage consists biodegradable organic matter and easily decomposes by the micro-organisms. These microorganisms can multiply using these organic substances as substrates and hence, utilize some of the components of sewage. Micro-organisms 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. 

Thus, the correct answer is option B.