Related Questions

The main pollutant in waste water discharged from a petroleum refinery is oil (both in free and emulsified form). Free oil is removed by
A Biological oxygen pond
B Aerated lagoons
C Trickling filters
D Gravity separator having oil skimming devices
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
After the increase of price of oil by 40%, a family decided to reduce its oil consumption so that the expenditure for oil goes up by 26% only. If the total consumption of oil before the price rise was 10 kg per month, then what is the current consumption of oil per month (in kg)?
A 8
B 8.50
C 9
D None of these
If the sewage contains grease and fatty oils, these are removed in
A Grit chambers
B Detritus tanks
C Skimming tanks
D Sedimentation tanks
Oilish impurities present the effluent discharged from the electroplating industry is normally not removed by
A Chemical coagulation
B Floatation & skimming
C Centrifugation
D Ultrafiltration
Coal mines drainage waste water (acidic in nature) results from the earth's water percolating through the voids created in coal bed during mining. This polluted water which either drains out naturally to water courses or are removed before starting the mining is
A Neutralised by alkali treatment
B Left as such without any treatment
C Diluted with fresh water to reduce its acidity
D None of these
Removal of oil and grease from sewage, is known
A Screening
B Skimming
C Filtration
D None of these
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
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
In a refinery petroleum crude is fractionated into gas fraction, light ends, intermediate distillates, heavy distillates, residues and by products. The group of products including gas oil, diesel oil and heavy fuel oil belongs to the fraction
A Heavy distillates
B Intermediate distillates
C Light ends
D Residues

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