Environmental Engineering Questions

• Ozone level is generally found to be depleted in India in the month of
• Moist atmospheric air at high temperature (e.g., in summer) having high concentration of sulphur dioxide causes
• Dose of chlorine for disinfection of water is about __________ mg/litre of water.
• What are the methods of treatment & disposal of radioactive wastes?
• Particles having diameter greater than 75 μm (micrometer = 10-6 mm) are called
• Sound produced by an automobile horn heard at a distance of 1.5 metres corresponds to about __________ decibels.
• Foul odour and bad taste of water is removed by treating with
• Presence of __________ hardness is responsible for the temporary hardness in water.
• Most efficient and suitable dust removal equipment for removal of flyash from flue gas in a thermal power plant is the
• Methyl iso-cynate (MIC) gas (TLV <1 ppm), which caused Bhopal gas tragedy in 1984 falls under the category of __________ toxic gas.
• Oil and grease present in an emulsified state in waste water discharged from industries can be removed by
• Presence of soluble organics in polluted water causes
• Noise produced by cooling fans (employed in air cooled heat exchangers or cooling tower) is mainly caused due to the turbulence created by blade passage through air. It can be reduced by use of a slower fan
• Waste/polluted water discharged from electroplating, blast furnace and coal mining industries contain mainly __________ substances.
• Foaming and priming in boiler operation can be reduced by reduction in __________ in feed water.
• COD of raw municipal sewage may be in the range of about __________ mg/litre.
• Noise level during normal conversation among men is about __________ decibles.
• Bacterial aerobic oxidation of polluted water in biological oxidation ponds is done to purify it. Presence of bacteria helps in
• Iron & manganese present in the polluted water is removed by
• The main industrial source of emission of hydrogen sulphide air pollutant is