Q. Foul smell in the water of tanks, ponds etc. is due to Anaerobiosis Aerobiosis Biological magnification Psammophytes Answer: Anaerobiosis

Q. Minamata disease is a pollution related disease results from Oil spills into sea Accumulation of arsenic into atmosphere Release of industrial waste mercury into fishing water Release human organic waste into drinking water Answer: Release of industrial waste mercury into fishing water

Q. The excessive discharge of fertilizers into water bodies results in Growth of fish Death of hydrophytes Eutrophication Silt Answer: Eutrophication

Q. Water pollution can be stopped best by Treating effluents to remove injurious chemicals Rearing more fishes Cultivating useful water plants Spraying with DDT Answer: Treating effluents to remove injurious chemicals

Q. When Chloride is added to sewage both at the beginning as well as at the end of the treatment process, the phenomenon is called: Post chlorination Super chlorination Split chlorination None of these Answer: Split chlorination

Q. In the treatment of waste water discharge, which treatment stage involves biological treatment Primary treatment Secondary treatment Tertiary treatment Reverse osmosis stage Answer: Secondary treatment

Q. Thermal pollution of water bodies is due to Discharge of heat (hot water) from power plants Discharge of chemicals from industries Discharge of waste from mining Discharges of agricultural run off Answer: Discharge of heat (hot water) from power plants

Q. Water pollution is caused due to Sewage and other wastes Industrial effluents Agricultural discharges All of these Answer: All of these

Q. The BOD removal in an oxidation pond may be up to 100% 97% 94% 90% Answer: 90%

Q. Sewage water can be purified for recycling with the action of Aquatic plants Penicillin Micro-organisms Fishes Answer: Micro-organisms