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CBSE Class 12-science Answered

Study the graph given below and answer the questions which follow:       (i) What is the relationship between dissolved oxygen and biochemical oxygen (BOD)? (ii) Mention their effect on aquatic life in the river.
Asked by Topperlearning User | 16 Jun, 2014, 01:22: PM
answered-by-expert Expert Answer

(i) BOD refers to the amount of oxygen required to decompose the organic matter present in one litre of water. Thus, greater the BOD, lesser will be the dissolved oxygen content in sewage discharge.

(ii) Effects on aquatic life:

(a) It causes high mortality of aquatic animals.

(b) The excessive nutrients facilitate algal growth causing algal bloom.

Answered by | 16 Jun, 2014, 03:22: PM

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