Tag: environmental use of microorganism

Questions Related to environmental use of microorganism

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

  1. Anaerobic digesters

  2. Floc

  3. Chemicals

  4. Oxidation pond


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

  1. Removes all the air pollutants

  2. Disinfects water by killing germs

  3. Removes hardness of water

  4. All of the above


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?

  1. Sewage treatment

  2. Production of methane

  3. Conversion of milk to curd

  4. Biological control of plants disease


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;

  1. Suspended solids

  2. Dissolved organic matters

  3. Floating materials

  4. Solid impurities


Correct Option: B

Sewage water is purified for reuse by the action of

  1. Protozoans

  2. Micro-organisms

  3. Plants and light

  4. Fish


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. 

In secondary treatment, solid reducers, ranges from

  1. 70-92%

  2. 80-90%

  3. 20-60%

  4. 10-70%


Correct Option: A

Secondary treatment is also known as ________________.

  1. Biological Treatment

  2. Preliminary Treatment

  3. Secondary Treatment

  4. Tertiary Treatment


Correct Option: A

Which of these is not a key factor that helps in the process of decay?

  1. Wind

  2. Temperature

  3. Water

  4. Micro-organisms


Correct Option: A
Explanation:

Decay is what happens when dead animals and plants break down. The key factors involved in decay are: Temperature, Amount of oxygen, Amount of water and the presence of microorganisms. Microorganisms are important in decay. For example, they are used to break down human waste (sewage) and plant waste (compost). Decay recycles important nutrients for plant growth.

Air pollution is caused by transport exhaust fumes and emission of gases like $SO 2$, $CO _, NO _2$ from industries. Similarly, water pollution is caused by ____________.

  1. Sewage

  2. Crop cultivation

  3. Rain

  4. Soil erosion


Correct Option: A

Passage of effluents into oxidation tank is for

  1. Primary treatment

  2. Secondary treatment

  3. Tertiary treatment

  4. Both A and B


Correct Option: B