Tag: wastewater treatment - need and methods

Questions Related to wastewater treatment - need and methods

Which of the following statements is correct ?

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  1. Activated sludge - sediment in settlement tanks of sewage treatment plant is a rich source of aerobic bacteria

  2. Biogas is produced by the activity of aerobic bacteria on animal feed

  3. Methanobacterium is an aerobic bacterium found in rumen of cattle.

  4. Biogas, commonly called gobar gas, is pure methane.

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Correct Option: A

Permutit is the trade name of a mixture 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. Hydrated silicates of Ca and Mg

  2. Hydrated silicates of Al and Na

  3. Hydrated aluminates of Ca and No

  4. None of these

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Correct Option: A
Explanation:
The permutit process is a process in where hard water containing such as Calcium is filtered through natural sand called the zeolite.
This is the hydrated silicate of Ca and Mg.
So, the correct option is 'Hydrated silicates of Ca and Mg'

Which of the following is correct for sewage discharge in river?

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. At the discharge point B.O.D is high and fishes die

  2. At the discharge point D.O. is high

  3. B.O.D increase downstream ion river

  4. From the discharge 50 KM away, Fishes ,die

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Correct Option: A

Select the correct statement from the following.

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. Activated sludge-sediment in settlement tanks of sewage treatment plant is a rich source of aerobic bacteria

  2. Biogas is produced by the activity of aerobic bacteria on animal waste

  3. Methano bacterium is an aerobic bacterium found in rumen of cattle

  4. Biogas, commonly called as global gas, is pure methane

Show answer
Correct Option: A
Explanation:

1. The effluent from aeration tank is passed into a settling tank where the aerobic bacterial ‘flocs’ are allowed to sediment and the sediment is called activated sludge.

2. Biogas is produced by the activity of anaerobic bacteria on activated sludge.
3. Methano bacterium is an anaerobic bacteria found in rumen of cattle.
4. Biogas is a mixture of gases such as methane, hydrogen sulphide and carbon dioxide.
So, the correct option is 'Activated sludge-sediment in settlement tanks of sewage treatment plant is a rich source of aerobic bacteria'.

Tertiary treatment of sewage is also known 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. Advance Treatment

  2. Preliminary Treatment

  3. Secondary Treatment

  4. Primary Treatment

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Correct Option: A

Secondary treatment reduces bacterial load, 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. 90-100%

  2. 80-98%

  3. 40-60%

  4. 10-30%

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Correct Option: B

Measurement of the rate of oxygen utilization by a unit volume of water over a period of time is to measure

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. Biochemical oxygen demand

  2. Biosynthetic pathway

  3. Biogas generation

  4. Fermentation

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Correct Option: A
Explanation:
  • Biochemical Oxygen Demand (BOD)is defined as the amount of dissolved oxygen needed (i.e. demanded) by aerobic biological organisms to break down organic material present in a given water sample at certain temperature over a specific time period.
  • BOD is an important water quality parameter because it provides an index to assess the effect discharged wastewater will have on the receiving environment. The higher the BOD value, the greater the amount of organic matter or “food” available for oxygen-consuming bacteria.
  • Hence Measurement of the rate of oxygen utilization by a unit volume of water over a period of time is to measure Biochemical oxygen demand.
  • So, the correct answer is 'Biochemical oxygen demand'.

Hard water does not easily produce lather with soap because it contains:

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. Only $Mg^{2+}$ ions

  2. Only $Ca^{2+}$ ions

  3. Both $Mg^{2+}$ and $Ca^{2+}$ ions

  4. Both $Na^+$ and $K^+$ ions

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Correct Option: C

The biological treatment of waste water makes use 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. Aerobic bacteria and fungi

  2. Anaerobic bacteria and algea

  3. Aerobic and anaerobic bacteia

  4. Anaerobic bacteria and Eucalyptus leaves

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Correct Option: C
Explanation:

Aerobic digestion of waste is the natural biological degradation and purification process in which bacteria that thrive in oxygen-rich environments break down and digest the waste. During oxidation process, pollutants are broken down into carbon dioxide ( CO$ _{2}$ ), water (H$ _{2}$O), nitrates, sulphates and biomass (microorganisms). By operating the oxygen supply with aerators, the process can be significantly accelerated. Of all the biological treatment methods, aerobic digestion is the most widespread process that is used throughout the world. Anaerobic digestion is a complex biochemical reaction carried out in a number of steps by several types of microorganisms that require little or no oxygen to live. During this process, a gas that is mainly composed of methane and carbon dioxide, also referred to as biogas, is produced. The amount of gas produced varies with the amount of organic waste fed to the digester and temperature influences the rate of decomposition and gas production. Wastewater pollutants are transformed into methane, carbon dioxide and smaller amount of bio-solids. The biomass growth is much lower compared to those in the aerobic processes. They are also much more compact than the aerobic bio-solids.

Physical treatment for the industrial wastes include sedimentation and filtration.

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. True

  2. False

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Correct Option: A
Explanation:
Filtration is commonly the mechanical or physical operation which is used for the separation of solids from fluids (liquids or gases) by interposing a medium through which only the fluid can pass. The fluid that passes through is called the filtrate.  Oversize solids in the fluid are retained, but the separation is not complete; solids will be contaminated with some fluid and filtrate will contain fine particles (depending on the pore size and filter thickness).
Sedimentation is a physical water treatment process using gravity to remove suspended solids from water. Solid particles entrained by the turbulence of moving water may be removed naturally by sedimentation in the still water of lakes and oceans.