A. 24 – 48 hours
B. 10-12 days
C. 2-3 months
D. 1-2 year
Period of cleaning of slow sand filters is about________________? Read More »
Environmental Engineering A. removal of turbidity
B. removal of hardness
C. killing of disease bacteria
D. complete sterilisation
Disinfection of water results in______________? Read More »
Environmental Engineering A. to increase the filtration slow sand filters capacity of
B. to increase the filtration rapid sand filters capacity of
C. for isolated buildings like pools, hotels etc swimming
D. all of the above
Double filtration is used_______________? Read More »
Environmental Engineering 1) decreasing the time of contact
2) decreasing the temperature of water
3) increasing the temperature of water
The correct answer is ?
A. only (1)
B. both (1) and (2)
C. both (1) and (3)
D. only (3)
The disinfection efficiency of chlorine increases by_______________? Read More »
Environmental Engineering A. prechlorination
B. post chlorination
C. super chlorination
D. break point chlorination
A. prechlorination
B. super chlorination
C. dechlorination
D. hypochlorination
The treatment of water with bleaching powder is known as________________? Read More »
Environmental Engineering A. carbon dioxide
B. bleaching powder
C. sulphur dioxide
D. chloramines
Which of the following chemical compounds can be used for dechlorination of water ? Read More »
Environmental Engineering A. smaller
B. larger
C. same
D. none of the above
In lime-soda process________________? Read More »
Environmental Engineering A. sodium sulphate
B. copper sulphate
C. sodium chloride
D. calcium chloride
Which of the following compounds is widely used for algae control ? Read More »
Environmental Engineering