Question

Which of the following statements is not true regarding BOD?

(a) Sewage water is treated until the BOD is reduced.

(b) BOD is a measure of organic matter present in the water

(c) Greater the BOD, lesser is the polluting potential of water

(d) BOD measures the rate of uptake of oxygen

The question was posed to me in final exam.

Origin of the question is Microbes in Sewage Treatment topic in division Microbes in Human Welfare of Biology – Class 12

Answer 1

Right option is (c) Greater the BOD, lesser is the polluting potential of water

Easiest explanation: The sewage water is treated until the BOD is reduced. The BOD test measures the rate of uptake of oxygen by micro-organisms in a sample of water and thus, BOD is indirectly a measure of the organic matter present in the water. The greater the BOD of waste-water more is its polluting potential.