What is the temperature at which sludge constituting biosolids are composted?

To what temperature is a sludge constituting liquid biosolids heated in order to treat it?

A

450 degree Celsius

B

200 degree Celsius

C

180 degree Celsius

D

300 degree Celsius

At what temperature the sludge constituting biosolids is heated, when it is treated by the pasteurization method?

A

45 degree Celsius

B

55 degree Celsius

C

70 degree Celsius

D

65 degree Celsius

For how many days the sludge constituting biosolids is subjected to composting?

A

1 day

B

2 days

C

3 days

D

5 days

What is the solid retention time assumed when the sludge constituting biosolids is treated anaerobically?

A

7 days

B

4 days

C

15 days

D

10 days

Statement (I): Anaerobic sludge digester, by itself, is considered to be the better method than other methods of sludge treatment: Statement (II): During anaerobic sludge digestion, CH4 is produced; also rodents and other pests are attracted when digester sludge is dried.

A

Both Statement (I) and Statement (II) are individually true; and Statement (II) is the correct explanation of Statement(I)

B

Both Statement (I) and Statement (II) are individually true; but Statement (II) is NOT the correct explanation of Statement (I)

C

Statement (I) is true; but Statement (II) is false

D

Statement (I) is false; but Statement (II) is true.

An impeller with radial vanes constituting the driving member and runner with radial vanes constituting the driven member is found in ______

A

Fluid coupling

B

Dog clutch

C

Friction clutch

D

Cone clutch

Consider the following statements as regards a Septic Tank: 1. The size required is large and uneconomical when serving more than roughly 100 persons. 2. It can remove around 90% of BOD and 80% of suspended solids. 3. As compared to the sludge holding of a plain sedimentation tank, a septic tank can hold about 90% less of sludge volume. 4. Frequent removal of sludge is not required. Which of the above statements are correct?

A

1 and 2

B

2 and 3

C

3 and 4

D

1 and 4

Which of the following are claimed as advantageous in respect of aerobic sludge digestion as compared to anaerobic sludge digestion? 1. Lower BOD concentration in supernatant liquor 2. Production of a sludge with excellent dewatering propensity. 3. Greater production of methane 4. Lesser operating cost 5. Lesser capital cost Select the correct answer using the codes given below:

A

(1), (2) and (4)

B

(2), (3), (4) and (5)

C

(3), (4) and (5)

D

(1), (2) and (5)

The moisture content of sludge is reduced from 90% to 80% in a sludge digestion tank. The percentage decrease in the volume of sludge, is

A

25 %

B

50 %

C

10 %

D

5 %

Composted manure is formed from

A

Animal refuse and rotten vegetables

B

Farm and household refuse

C

Organic wastes from where biogas extraction takes place

D

Green and farmyard manure

What is the temperature at which sludge constituting biosolids are composted?

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