Q. Oil and grease present in an emulsified state in waste water discharged from industries can be removed by

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Q. The amount of chemical coagulant added for treatment of polluted water __________ with increase in temperature of the polluted water to be treated.

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Q. Particles having diameter greater than 75 μm (micrometer = 10⁻⁶ mm) are called

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Q. Which of the following is the most severe air pollutant ?

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Q. Presence of bacteria in potable (drinking) water causes

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Q. Which of the following radioactive wastes emits all α, β & γ rays and hence is the most hazardous of all radioactive emitters?

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Q. COD of raw municipal sewage may be in the range of about __________ mg/litre.

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Q. Maximum permissible turbidity in potable water is __________ ppm.

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Q. Presence of __________ hardness is responsible for the temporary hardness in water.

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Q. Dose of chlorine for disinfection of water is about __________ mg/litre of water.

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Q. Foul odour and bad taste of water is removed by treating with

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Q. Presence of __________ in water stream are deleterious to aquatic life.

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Q. Acute danger to human life (i.e. death) exists, if the concentration of CO₂ in atmospheric air exceeds __________ percent (by volume).

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Q. Methyl iso-cynate (MIC) gas (TLV <1 ppm), which caused Bhopal gas tragedy in 1984 falls under the category of __________ toxic gas.

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Q. Noise level heard inside a bus in busy city traffic or inside a sub-way train corresponds to about __________ decibels.

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Q. Workers working in __________ industry are most prone to white lung cancer.

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Q. A standard test for determination of hardness in water is termed as __________ test.

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Q. TLV of lead for public sewer/waste water is about __________ ppm.

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Q. Presence of nitrates in water in excess of 50 ppm causes

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Q. In sewage treatment, the detention period allowed for oxidation ponds ranges from __________ weeks.

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