Environmental Engineering In Ce - Study Mode

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[#236] COD of raw municipal sewage may be in the range of about __________ mg/litre.

(A) 1-2

(B) 5-10

(C) 90-120

(D) 1500-2500

Correct Answer

(C) 90-120

[#237] BOD of raw municipal sewage may be in the range of about __________ mg/litre.

(A) 1-2

(B) 5-10

(C) 150-300

(D) 2000-3000

Correct Answer

(C) 150-300

[#238] Threshold limit value (TLV) means maximum permissible/acceptable concentration. TLV of phosgene in air is about __________ ppm (parts per million).

(A) 0.002

(B) 0.2

(C) 1.2

(D) 4.8

Correct Answer

(B) 0.2

[#239] Maximum permissible concentration (i.e. TLV) of DDT in public water supply system is __________ micro gram (μ g)/litre.

(A) 2

(B) 42

(C) 332

(D) 1050

Correct Answer

(B) 42

[#240] CFC (chloro fluoro carbon) is very highly reactive in causing depletion of ozone layer in the atmosphere. Each atom of chlorine liberated from CFC is capable of decomposing __________ molecules of ozones.

(A) 10 2

(B) 10 5

(C) 10 9

(D) 10 15

Correct Answer

(B) 10 5