Presence of ____________ in water stream are deleterious to aquatic life?

Related Mcqs:

1. A butane isomerisation process produces 70 k.mole/hr of pure iso-butane. A purge stream removed continuously, contains 85% n-butane and 15% impurity (mole%). The feed stream is n-butane containing 1% impurity (mole%). The flow rate of the purge stream will be_________________?

   A. 3 kmole/hr B. 4 kmole/hr C. 5 kmole/hr D. 6 kmole/hr...

2. For existence of aquatic life in water, the dissolved oxygen content in it, should not be less than ______________ ppm?

   A. 10000 B. 5 C. 500 D. 1000...

3. The detrimental effect on organism and water quality with temperature rise of aquatic system is the reduction of _____________ of water?

   A. Dissolved oxygen content B. Biological oxygen demand C. Vapor pressure D. All A., B. and C....

4. Which of the following is the most efficient for removal of very finely divided suspended solids and colloidal matter from the polluted water stream ?

   A. Sedimentation tank B. Circular clarifier C. Mechanical flocculation D. Chemical coagulation...

5. Replenishment of dissolved oxygen in water stream polluted with industrial waste occurs by________________?

   A. Natural aeration of water stream B. Photosynthetic action of algae C. Both A. & B. D. Neither A. nor B....

6. Radioactive substances present in the polluted water stream can be removed by_________________?

   A. Biological oxygen treatment B. Coagulation and filtration C. Adsorption in ion exchange materials D. None of these...

7. Fluorosis is caused due to the presence of excessive amount of ______________ in drinking water?

   A. Mercury B. Lead C. Fluoride D. Arsenic...

8. Presence of nitrogen and phosphorous in waste water discharged into lakes and ponds causes_______________?

   A. Foaming B. Odour nuisances C. Undesirable plant growth D. Turbidity...

9. Presence of _____________ hardness is responsible for the temporary hardness in water?

   A. Carbonate B. Calcium C. Chloride D. Sulphate...

10. Presence of excess fluorine in water causes__________________?

    A. Dental cavity B. Tooth decay C. Fluorosis D. Respiratory disease...