Particles having diameter greater than 75 μm (micrometer = 10-6 mm) are called__________________?
A. Grit
B. Dust
C. Powder
D. Smoke
Chemical Environmental Engineering
Coal washing waste water containing about 3% suspended solids (comprising of clay, slate, stone etc.) is treated for solid particles removal ?
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
Removal of ______________ is accomplished by aeration of water?
Removal of ______________ is accomplished by aeration of water?
A. Dissolved gases
B. Suspended solids
C. Dissolved solids
D. None of these
Which of the following pollutants, if present in atmosphere is detectable by its odour ?
Which of the following pollutants, if present in atmosphere is detectable by its odour ?
A. CO
B. SO2
C. NO2
D. CO2
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) ?
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
When the concentration of SO2 in air is greater than ______________ ppm, it gives a pungent smell?
When the concentration of SO2 in air is greater than ______________ ppm, it gives a pungent smell?
A. 0.01
B. 0.1
C. 1
D. 4
Which is the most practical and economical method for removal of suspended solid matter from polluted water ?
Which is the most practical and economical method for removal of suspended solid matter from polluted water ?
A. Sedimentation
B. Skimming off
C. Chlorination
D. Biological oxidation
Iron & manganese present as pollutant in water cannot be removed by__________________?
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
In the context of the chemical process industries, the term BOD is normally associated with the_____________________?
In the context of the chemical process industries, the term BOD is normally associated with the_____________________?
A. Characterisation of solid wastes
B. Organic concentration in gaseous effluents
C. Characterisation of liquid effluents
D. Characterisation of boiler feed water
Pick out the wrong statement pertaining to ‘green house’ for the plants ?
Pick out the wrong statement pertaining to ‘green house’ for the plants ?
A. ‘Green house’ (made of glass) allows visible sunlight (i.e., short wavelength solar radiation
like ultra-violet rays) to pass through the glass and heat up the soil thereby warming up plants
inside it
B. The emitted longer wavelength radiation (e.g., infrared) is partly reflected and partly absorbed
by the glass of the green house
C. ‘Green house effect’ in earth’s atmosphere is due to increasing CO2 level in atmosphere, where
CO2 acts like the glass of ‘green house’ thereby warming up the earth’s surface
D. ‘Green house’ is colder than the outside atmosphere