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SSC Ecology And Environment Sample Paper NCERT Sample Paper-5

  • question_answer
    When a huge amounts of sewage is dumped into a river, it's BOD

    A)  Increases          

    B)  decreases

    C)  Sharply decrease

    D)  remains unchanged

    Correct Answer: A

    Solution :

    [a] By dumping of a huge amount of sewage, the oxygen levels are depleted, which are reflected in terms of BOD values of water. The number of microbes also increases tremendously and these also consume most of the oxygen. As a result of this, the BOD of the river water increases.


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