A. Biological oxygen treatment
B. Coagulation and filtration
C. Adsorption in ion exchange materials
D. None of these
Related Mcqs:
- 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 - Iron & manganese present in the polluted water is removed by __________________?
A. Simple filtration
B. Oxidation followed by settling & filtration
C. Chemical coagulation
D. Chlorination only - 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 - 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. - 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 - H2S present in gaseous stream can be removed by adsorption on _____________________?
A. Silica gel
B. Active carbon
C. Bog iron
D. Limestone powder - ____________ substances present in sewage are removed in grit chamber during sewage treatment?
A. Organic
B. Fatty
C. Inorganic
D. Dissolved - Which of the following radioactive wastes emits all α, β & γ rays and hence is the most hazardous of all radioactive emitters ?
A. I-131
B. Sr-90
C. Au-198
D. Ra-226 - 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 - 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
