Category: Chemical Environmental Engineering

A. Quenching of hot coke
B. Discharging in the river stream
C. Filtration and recycling for cooling coke oven gas
D. None of these

A. SPM
B. Thermal pollution
C. Radioactive rays
D. Noise pollution

A. Low amount of excess combustion air
B. Large quantity of excess combustion air
C. Hydrocarbon fuel
D. Pulverised coal as fuel

A. Automobile exhaust
B. Blanketing effect of CO2 in the atmosphere
C. De-forestation
D. Thickening of ozone layer

A. 1-2
B. 5-10
C. 150-300
D. 2000-3000

A. Biological oxygen demand (BOD) is a characteristic and not a constituent of water
B. BOD is a measure of the amount of oxygen which will be demanded & used in 5 days by the
biological decomposition of the organic matter present in water stream present as food for the
living organism
C. BOD is expressed in mg/litre (typically, BOD=2.5 mg/litre for potable water)
D. None of these

A. Chemical oxygen demand (COD) is a measure of chemically oxidisable organic matter present
in water
B. COD is determined by oxidising the organic matter present in water with potassium
dichromate in cone, sulphuric acid solution at boiling temperature for specified time
C. COD is related to BOD of a given waste in water but the relationship varies for different
wastes. Typically COD of potable water may be 1-2 mg/litre
D. All A., B. and C.

A. CO
B. SO2
C. NOx
D. CFC (chloro fluoro carbons)

A. 105
B. 135
C. 160
D. 185

A. Bog iron
B. Limestone powder or alkalised alumina
C. Silica gel
D. Active carbon