Newspaper can be recycled again and again how many times ?

A. 2
B. 3
C. 4
D. 5

The main pollutant of leather tanneries in the waste water is____________________?

A. Chromium iii
B. Chromium iv
C. Chromium v
D. Chromium vi

Which substance can be used for disinfecting water ?

A. Kmno4
B. Alums
C. Ozone
D. All

Which one of the following makes the bulk of hydrospheres content ?

A. Oceans
B. Glaciers & icecaps
C. Fresh water lakes and ponds
D. All have equal distribution

The percentage of suspended solid waste in raw water is removed by coagulation is__________________?

A. 60
B. 70
C. 80
D. 90

The main product of bacterial action is_________________?

A. Nox
B. No2
C. N2o3
D. No

Pollutants have adverse effect over_________________?

A. Biosphere
B. Ecosystem
C. Both a & b
D. Hydrosphere

Which of the following is not a heavy industry ?

A. Iron
B. Fertilizer
C. Paper
D. None

Three elements needed for the healthy growth of plants are_________________?

A. N p k
B. N k c
C. N s p
D. N ca p

Residence time of methane in the atmosphere is___________________?

A. 3 – 7 days
B. 2 -3 days
C. 3 – 7 years
D. 2 – 3 years