Relationship between DO and BOD is that they
are directly proportional
are inversely proportional
are not related
always remain equal to each other
B.
are inversely proportional
BOD or Biological Oxygen Demand is a measure of the amount of oxygen needed by microbes to breakdown the organic matter in a sample of water. DO or Dissolved Oxygen is the amount of oxygen dissolved in the water.
BOD and DO are inversely proportional to each other. When BOD is high, it means there's a lot of organic contaminants in the water and the microbes are working overtime to break it down. They use up oxygen while doing this. So, when BOD is high, Do is low.
Phenomenon involving increase in concentration of non-degradable pollutants from lower to higher trophic levels is called
biomagnification
bioaccumulation
biodegradation
bioinvasion
'Kyoto Protocol' is a multination international treaty for
phasing out green house gases
controlling ozone destroying substances
management of hazardous wastes
conservation of biodiversity
During waste water treatment, trickling filter is used for
primary treatment
secondary aerobic treatment
secondary anaerobic treatment
tertiary treatment
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
During 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
With the rise of water temperature, dissolved oxygen
remains unchanged
increases in amount
decreases in amount
is more available to the aquatic organisms
