Environmental Engineering Questions

• Which of the following industries discharge mercury as a pollutant?
• Oilish impurities present the effluent discharged from the electroplating industry is normally not removed by
• From pollution control point of view, the maximum permissible concentration of sulphur dioxide in atmospheric air is about __________ ppm.
• The function of skimming tank in sewage treatment is to remove __________ substances.
• 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
• The destruction of water-borne pathogens is termed as disinfection of water. Which of the following is a water disinfectant?
• The principal gas evolved from sludge digestion tank is
• Presence of nitrogen and phosphorous in waste water discharged into lakes and ponds causes
• Infective bacteria in water is killed by the __________ process.
• Which of the following pollutants is absent in the emissions from a fertiliser plant?
• Threshold limit value (TLV) i.e., the maximum permissible safe limit of phosgene gas which Hitler used to use to kill his enemies in 'gas chamber' is about __________ ppm.
• The term Biological Oxygen Demand (BOD) is used in relation to
• Maximum permissible limit of mercury in human blood is __________ micrograms/100 c.c.
• Which is the most widely used coagulant for the treatment of turbid water?
• Lagoons used for purification of polluted water
• Salt content in sea water is about __________ percent.
• The pH value of oxidised sewage is about
• In large thermal power stations very fine particulates present in flue gas are removed by
• What is the major constituents of waste/polluted water discharged from textile, pulp & paper, tanning, distillary, dairy and meat packing industries?
• Which of the following processes is involved in the biochemical treatment of sewage effluents?