Chemical Environmental Engineering Archives -

The main pollutant in waste water discharged from a petroleum refinery is oil (both in free and emulsified form). Free oil is removed by_________________?

Chemical Environmental Engineering / admin

The main pollutant in waste water discharged from a petroleum refinery is oil (both in free and emulsified form). Free oil is removed by_________________?

A. Biological oxygen pond
B. Aerated lagoons
C. Trickling filters
D. Gravity separator having oil skimming devices

The main pollutant in waste water discharged from a petroleum refinery is oil (both in free and emulsified form). Free oil is removed by_________________? Read More »

Chemical Environmental Engineering

Noise emitted by a ventilation fan at a distance of 3 metres is about _____________ decibels?

Chemical Environmental Engineering / admin

Noise emitted by a ventilation fan at a distance of 3 metres is about _____________ decibels?

A. 85
B. 105
C. 125
D. 145

Noise emitted by a ventilation fan at a distance of 3 metres is about _____________ decibels? Read More »

Chemical Environmental Engineering

Presence of ____________ in water stream are deleterious to aquatic life?

Chemical Environmental Engineering / admin

Presence of ____________ in water stream are deleterious to aquatic life?

A. Soluble and toxic organics
B. Suspended solids
C. Heavy metals and cyanides
D. All A., B. & C.

Presence of ____________ in water stream are deleterious to aquatic life? Read More »

Chemical Environmental Engineering

Tolerable limit of nitrogen oxides in air is _____________ ppm?

Chemical Environmental Engineering / admin

Tolerable limit of nitrogen oxides in air is _____________ ppm?

A. 0.1
B. 1
C. 5
D. 25

Tolerable limit of nitrogen oxides in air is _____________ ppm? Read More »

Chemical Environmental Engineering

BOD of raw municipal sewage may be in the range of about _____________ mg/litre?

Chemical Environmental Engineering / admin

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

BOD of raw municipal sewage may be in the range of about _____________ mg/litre? Read More »

Chemical Environmental Engineering

Iron & manganese present in the polluted water is removed by __________________?

Chemical Environmental Engineering / admin

Iron & manganese present in the polluted water is removed by __________________?

A. Simple filtration
B. Oxidation followed by settling & filtration
C. Chemical coagulation
D. Chlorination only

Iron & manganese present in the polluted water is removed by __________________? Read More »

Chemical Environmental Engineering

TLV of aldrin in public water supply system is about ____________ μg/litre?

Chemical Environmental Engineering / admin

TLV of aldrin in public water supply system is about ____________ μg/litre?

A. 0.5
B. 17
C. 357
D. 1097

TLV of aldrin in public water supply system is about ____________ μg/litre? Read More »

Chemical Environmental Engineering

Aerobic biological oxidation ponds used for the purification of polluted water__________________?

Chemical Environmental Engineering / admin

Aerobic biological oxidation ponds used for the purification of polluted water__________________?

A. Destroys/removes pathogen from the sewage
B. Is not very effective for non-biodegradable substances (e.g. ABS) containing effluents
C. Destroys/removes pathogen much more effectively if the sewage is chlorinated
D. All A., B. & C.

Aerobic biological oxidation ponds used for the purification of polluted water__________________? Read More »

Chemical Environmental Engineering