Category: Environmental Engineering

A. 0.1 mg/litre
B. 1.5 mg/litre
C. 5 mg/litre
D. 10 mg/litre

A. less and more
B. less and less
C. more and less
D. more and more

A. large area is required for construction
B. maintenance and operation cost are high
C. BOD removal is very low
D. none of the above

A. 1000
B. 4000
C. 100000
D. 400000

A. much greater than 1
B. slightly less than 1
C. equal to 1
D. slightly greater than 1

1) involves successive trials
2) takes economic aspects into account
3) is time consuming
The correct answer is?

A. only (1)
B. (1)and(2)
C. (1) and (3)
D. all are correct

A. only carbonate hardness is removed
B. only non-carbonate hardness is re-moved
C. lime reduces the carbonate hardness and soda-ash removes the non-carbo¬nate hardness
D. lime reduces the non-carbonate hard-ness and soda-ash removes the carbo¬nate hardness

A. equal to dry weather flow (DWF)
B. 2xDWF
C. 3 x DWF
D. 6xDWF

A. contains pathogenic bacteria
B. consists of undesirable substances rendering it unfit for drinking and domestic use
C. is safe and suitable for drinking and domestic use
D. is contaminated

A. 10 years
B. 25 years
C. 50 years
D. 75 years