Category: Environmental Engineering

A. 5-10 years
B. 15-20 years
C. 30-40 years
D. 40-50 years

A. 0.1 ppm
B. 0.01 ppm
C. 0.001 ppm
D. 0.0001 ppm

A. specific gravity of solid particles
B. size of particles
C. depth of tank
D. temperature of liquid

A. 1 minute
B. 5 minutes
C. 2-4 hours
D. 12 hours

A. 50 to 60
B. 100 to 150
C. 500 to 600
D. 1400 to 1500

A. excessive negative head
B. mud ball formation
C. higher turbidity in the effluent
D. low temperature

A. prechlorination
B. super chlorination
C. dechlorination
D. hypochlorination

A. nitrogen
B. carbon dioxide
C. hydrogen sulphide
D. methane

A. dissolved oxygen
B. residual chlorine
C. biochemical oxygen demand
D. dose of coagulant

A. suspended impurities
B. dissolved impurities
C. both suspended and dissolved impuri¬ties
D. none of the above