BIOLOGY IN HUMAN WELFARE
MICROBES IN HUMAN WELFARE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Amount of CO2 consumed if all the inorganic matter in one litre of water is oxidized by bacteria.
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Amount of O2 consumed if all the organic matter in one decilitre of water is reduced by bacteria.
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Amount of O2 consumed if all the organic matter in one litre of water is oxidized by bacteria.
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Amount of O2 consumed if all the inorganic matter in one litre of water is oxidized by bacteria.
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Detailed explanation-1: -Statement 1 : BOD represents the amount of dissolved oxygen that would be consumed if all the organic matter in one litre of water were oxidised by microorganisms. Statement 2 : High value of BOD indicates that water is highly polluted by organic matter.
Detailed explanation-2: -BOD also called biological oxygen demand, is the amount of dissolved oxygen needed by aerobic biological organisms to break down organic material present in a given water sample at a certain temperature. The Explanation for the incorrect option: It is not the photochemical breakdown of waste.
Detailed explanation-3: -BOD is defined as the amount of dissolved oxygen needed by aerobic biological organisms in a body of water to break down the organic material present in a water sample, at a specific temperature and specified period.
Detailed explanation-4: -The amount of oxygen required by bacteria to break down the organic matter present in a certain volume of a sample of water is called Biochemical Oxygen Demand (BOD). The amount of BOD in the water is the measure of the amount of organic material in the water.
Detailed explanation-5: -BOD values range widely; generally, pristine waters have a value below 1 mg l−1, moderately polluted waters 2–8 mg l−1, and treated municipal sewage 20 mg l−1. Standards for the discharge of effluent from WWTPs have the range 20–30 mg l−1 and require a minimum flow in receiving waters to ensure sufficient dilution.