The main pollutant in waste water discharged from a petroleum refinery is oil (both in free and emulsified form). Free oil is removed by_________________?

Related Mcqs:

1. Presence of nitrogen and phosphorous in waste water discharged into lakes and ponds causes_______________?

   A. Foaming
   B. Odour nuisances
   C. Undesirable plant growth
   D. Turbidity

2. Waste/polluted water discharged from electroplating, blast furnace and coal mining industries contain mainly _____________ substances?

   A. Radioactive
   B. Organic
   C. Inorganic
   D. None of these

3. Iron & manganese present as pollutant in water cannot be removed by__________________?

   A. Ion exchange process
   B. Oxidation followed by settling & filtration
   C. Lime soda process or manganese zeolite process
   D. Chlorination

4. Oilish impurities present the effluent discharged from the electroplating industry is normally not removed by _____________________?

   A. Chemical coagulation
   B. Floatation & skimming
   C. Centrifugation
   D. Ultra filtration

5. Suspended solid present in the waste water generated in blast furnace gas cooling and cleaning plant is removed by__________________?

   A. Biological oxygen pond
   B. Radial settling tank (thickener) using coagulant (lime & ferrous sulphate)
   C. Lagoons
   D. Filtration

6. Radioactive substances present in the polluted water stream can be removed by_________________?

   A. Biological oxygen treatment
   B. Coagulation and filtration
   C. Adsorption in ion exchange materials
   D. None of these

7. 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?

   A. Coal ash
   B. Potassium cyanide
   C. Ortho-xylene
   D. None of these

8. The main industrial source of emission of hydrogen sulphide air pollutant is________________?

   A. Petroleum refineries
   B. Coal based thermal power plants
   C. Pulp and paper plant
   D. Metallurgical roasting & smelting plant

9. Main pollutants released from petroleum refineries is__________________?

   A. CO, SO2 & H2S
   B. CO2, NO & SO3
   C. CO2, H2S & NO2
   D. SO3, NO2 & CO2

10. ‘Safe limit’ called Threshold Limit Value (TLV) of carbon monoxide in atmospheric air is < 50 ppm. The main source of carbon monoxide pollutant in air is the____________________?

    A. Industrial chimney exhaust
    B. Automobiles exhaust
    C. Photochemical reaction in polluted atmosphere
    D. Burning of domestic fuel