Q. Presence of iron and manganese in water causes

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Q. Septic tanks are used for the __________ of the deposited solids.

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Q. The term Biological Oxygen Demand (BOD) is used in relation to

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Q. The destruction of water-borne pathogens is termed as disinfection of water. Which of the following is a water disinfectant ?

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Q. Disinfection of water is done to destroy pathogenic bacteria and thus prevent water-borne diseases. Disinfection of water may be done by the use of

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Q. Which of the following processes is involved in the biochemical treatment of sewage effluents ?

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Q. Infective bacteria in water is killed by the __________ process.

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Q. Which of the following pollutants is absent in the emissions from a fertiliser plant ?

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Q. Salt content in sea water is about __________ percent.

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Q. Noise level inside a jet air liner in normal flight is about __________ decibels.

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Q. What is the major constituents of waste/polluted water discharged from textile, pulp & paper, tanning, distillary, dairy and meat packing industries ?

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Q. Water filtration rate in a rapid sand filter ranges from __________ kilolitres/m²/hr.

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Q. Hazardous/polluting chemical industries should have an 'exclusion zone' with a green belt and general public access prohibited around it, covering a radius of ____ metres.

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Q. Maximum permissible residual chlorine in treated water should be __________ mg/litre.

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Q. Which of the following is the most active zone of atmosphere in which weathering events like rain, storm & lightning occur ?

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Q. Which is the most widely used coagulant for the treatment of turbid water ?

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Q. Which of the following is not a natural source of air pollution ?

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Q. Which of the following industries discharge mercury as a pollutant ?

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Q. Threshold limit value (TLV) of CO in air is __________ ppm.

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Q. Lead exhausted in the atmosphere by automobiles using leaded petrol (i.e. tetraethyl lead for improving octane number) is a lethal air pollutant which causes

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