Which of the following radioactive wastes emits all α, β & γ rays and hence is the most hazardous of all radioactive emitters?
COD of raw municipal sewage may be in the range of about __________ mg/litre.
Maximum permissible turbidity in potable water is __________ ppm.
Presence of __________ hardness is responsible for the temporary hardness in water.
Dose of chlorine for disinfection of water is about __________ mg/litre of water.
Atmospheric pollution caused by the exhaust gas of supresonic transport air-crafts is mostly in the atmospheric region called
Iron & manganese present in the polluted water is removed by
Water effluent generated in printing industry is decolourised by
A shallow pond in which the sewage is retained and biologically treated is called
Which is the most practical and economical method for removal of suspended solid matter from polluted water ?
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.
__________ can not control the noise pollution.
Ozone level is generally found to be depleted in India in the month of
Noise level during normal conversation among men is about __________ decibles.
'Particulate' air pollutants are finely divided solids and liquids. Which of the following is not a 'particulate' ?
Foul odour and bad taste of water is removed by treating with
Presence of __________ in water stream are deleterious to aquatic life.
Acute danger to human life (i.e. death) exists, if the concentration of CO2 in atmospheric air exceeds __________ percent (by volume).
Methyl iso-cynate (MIC) gas (TLV <1 ppm), which caused Bhopal gas tragedy in 1984 falls under the category of __________ toxic gas.
Noise level heard inside a bus in busy city traffic or inside a sub-way train corresponds to about __________ decibels.
Presence of volatile compounds like gasoline, oil, alcohol, ether etc. in municipal sewers may cause
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
Presence of soluble organics in polluted water causes
Which of the following pollutants, if present in atmosphere is detectable by its odour ?
Exposure to chemicals having carcinogenic properties cause