Multiple Choice QuestionsDuring sewage treatment, biogases are produced, which include
methane, hydrogen sulphide and carbon dioxide
methane, oxygen and hydrogen sulphide
hydrogen sulphide, methane and sulphur dioxide
hydrogen sulphide, nitrogen and methane
A.
methane, hydrogen sulphide and carbon dioxide
Biogas is a mixture of gases (mainly methane) produced by the microbial activity and which may be used as fuel. During biogas production, the bacteria called methanogens digest the activated sludge and produce a mixture of gases such as methane, hydrogen sulphide, carbon dioxide and hydrogen.
Global warming can be controlled by
Reducing deforestation, cutting down use of fossil fuel
Reducing reforestation, increasing the use of fossil fuel
Increasing deforestation, slowing down the growth of human population
Increasing deforestation, reducing efficiency of energy usage
With the rise of water temperature, dissolved oxygen
remains unchanged
increases in amount
decreases in amount
is more available to the aquatic organisms
'Kyoto Protocol' is a multination international treaty for
phasing out green house gases
controlling ozone destroying substances
management of hazardous wastes
conservation of biodiversity
Phenomenon involving increase in concentration of non-degradable pollutants from lower to higher trophic levels is called
biomagnification
bioaccumulation
biodegradation
bioinvasion
During waste water treatment, trickling filter is used for
primary treatment
secondary aerobic treatment
secondary anaerobic treatment
tertiary treatment
Relationship between DO and BOD is that they
are directly proportional
are inversely proportional
are not related
always remain equal to each other
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