1. Ambient noise level can be reduced by __________ decibels by planting trees (like coconut, neem etc.) near public utility buildings (like hospitals & schools)
2. Thermal pollution of water increases its toxicity and oxidation of oxygen demanding waste besides favouring bacterial growth. A rise in water temperature by 10°C, doubles the toxic effects of __________ present in it
3. Presence of bacteria in potable (drinking) water causes
4. Iron & manganese present in the polluted water is removed by
5. Maximum permissible turbidity in potable water is __________ ppm
6. Which is the most practical and economical method for removal of suspended solid matter from polluted water ?
7. Atmospheric pollution caused by the exhaust gas of supresonic transport air-crafts is mostly in the atmospheric region called
8. The amount of chemical coagulant added for treatment of polluted water __________ with increase in temperature of the polluted water to be treated
9. A shallow pond in which the sewage is retained and biologically treated is called
10. Pick out the wrong statement
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