Category: Chemical Environmental Engineering

A. Decreases
B. Increases
C. Remain constant
D. May increase or decrease; depends on the chemical characteristics of polluted water

A. 1
B. 4
C. 8
D. 12

A. Air binding
B. Shrinkage of filtering media
C. Mud balls
D. Expansion of filtering media

A. Foodstuffs
B. Woolen clothes
C. Metallic powder
D. None of these

A. Are large shallow artificial lakes also known as clarification lakes, maturation ponds or
oxidation ponds
B. Use micro-organisms/bacteria in presence of dissolved oxygen
C. Gives an excellent final effluent (with 3 to 4 lagoons arranged in series) having suspended
solid < 1 mg/litre and BOD = 3.8 mg/litre
D. All A., B. & C.

A. Respiratory ailments (e.g. bronchitis)
B. Skin diseases (e.g. dermatitis)
C. Silicosis
D. Blurred vision

A. 35
B. 75
C. 95
D. 105

A. By chemical coagulation
B. In sedimentation tanks equipped with mechanical scrapper
C. In vacuum filter
D. In clarifiers

A. Dissolved solid
B. Suspended solid
C. Oil & fatty
D. Gritty & inorganic

A. Ozone
B. Photochemical smog
C. Sulphur dioxide
D. All A., B. & C.