Environmental Engineering Questions

• Particulates (< 1μm size) remaining suspended in air indefinitely and transported by wind currents are called
• Turbidity of water is an indication of the presence of
• TLV of ozone (O3) and phosgene (COCl2) in air is __________ ppm.
• Aerodynamic noise resulting from turbulent gas flow is the most prevalent source of valve noise in fluid ilow control. It is caused due to
• Ionisation potential employed in the industrial electrostatic precipitator is of the order of
• The main pollutant in waste water discharged from a petroleum refinery is oil (both in free and emulsified form). Free oil is removed by
• Fluorosis (a bone disease) is caused by the presence of high concentration of __________ in atmospheric air.
• Threshold Limit Value (TLV) is the maximum allowable concentration (i.e. safe limit) of pollutants in air. Safe limit for SO2 in air is __________ ppm.
• Maximum allowable concentration of CO2 in air for safe working is __________ ppm (parts per million).
• Inhalation of lead compounds present in the automobile exhausts (using leaded petrol) causes
• Operating principle of cyclone separator is based on the action of __________ dust particles.
• Coal washing waste water containing about 3% suspended solids (comprising of clay, slate, stone etc.) is treated for solid particles removal
• The ratio of oxygen available to the oxygen required for stabilisation of sewage is called the
• Scale formation in boiler is controlled by
• Most of the atmospheric air pollutants are present in large quantity in
• Replenishment of dissolved oxygen in water stream polluted with industrial waste occurs by
• H2S present in gaseous stream can be removed by adsorption on
• Aerobic biological oxidation ponds used for the purification of polluted water
• Polluted water having low BOD are most economically treated in
• Dust collection efficiency of a cyclone separator depends upon its