A. Sedimentation
B. Skimming off
C. Chlorination
D. Biological oxidation
Related Mcqs:
- Which of the following is the most efficient for removal of very finely divided suspended solids and colloidal matter from the polluted water stream ?
A. Sedimentation tank
B. Circular clarifier
C. Mechanical flocculation
D. Chemical coagulation - Coal washing waste water containing about 3% suspended solids (comprising of clay, slate, stone etc.) is treated for solid particles removal ?
A. By chemical coagulation
B. In sedimentation tanks equipped with mechanical scrapper
C. In vacuum filter
D. In clarifiers - The amount of chemical coagulant added for treatment of polluted water ______________ with increase in temperature of the polluted water to be treated?
A. Decreases
B. Increases
C. Remain constant
D. May increase or decrease; depends on the chemical characteristics of polluted water - Which is the best and the most effective method for the removal of organic contaminant present in the polluted water in very small quantity (say < 200 mg/litre) ?
A. Lagooning
B. Activated carbon adsorption
C. Biological oxidation pond
D. Chemical coagulation - 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 - Which is the most efficient dust removal equipment for removal of submicronic dust particles from blast furnace gas ?
A. Packed scrubber
B. Gravity settling chamber
C. Electrostatic precipitator
D. Hydrocyclone - Most efficient and suitable dust removal equipment for removal of fly-ash from flue gas in a thermal power plant is the__________________?
A. Gravity settling chamber
B. Cyclone separator
C. Electrostatic precipitator
D. Bag filter - Which of the following is not a practical method of low level radioactive waste disposal ?
A. Dilution with inert material
B. Discharging to atmosphere through tall stacks after dilution
C. Disposing off in rivers & oceans
D. Filling in steel crates and shooting it off out of earth’s gravity - Bacterial aerobic oxidation of polluted water in biological oxidation ponds is done to purify it. Presence of bacteria helps in____________________?
A. Coagulation and flocculation of colloids
B. Oxidation of carbonaceous matter to CO2
C. Nitrification or oxidation of ammonia derived from breakdown of nitrogenous organic matter
to the nitrite and eventually to the nitrate
D. All A., B. and C. - Replenishment of dissolved oxygen in water stream polluted with industrial waste occurs by________________?
A. Natural aeration of water stream
B. Photosynthetic action of algae
C. Both A. & B.
D. Neither A. nor B.
