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Environmental Chemistry — Chemistry STD 11 Science — Question

Gujarat BoardEnglish MediumSTD 11 ScienceChemistryEnvironmental Chemistry1 Mark
Question
Dissolved oxygen in water is very important for aquatic life. What processes are responsible for the reduction of dissolved oxygen in water?
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Answer

The discharge of human sewage and organic waste from pulp and paper industry and presence of leaves, grass, trash etc. in water due to run off result in phytoplankton growth. The microorganisms which decompose this organic matter need oxygen. Hence, the amount of oxygen in water of lakes etc. decreases.

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