Read the following statements and select the correct option.Statement ...
BOD (biochemical oxygen demand) refers to the amount of the oxygen that would be consumed if all the organic matter in one litre of water were oxidised by bacteria. The BOD test measures the rate of update of oxygen by microorganisms in a sample of water and thus, indirectly BOD is the measure of the organic matter present in the water. The greater the BOD of wastewater, more is its polluting potential.
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Read the following statements and select the correct option.Statement ...
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.
The first statement is correct. BOD stands for Biochemical Oxygen Demand, and it measures the amount of dissolved oxygen that is required by microorganisms to break down organic matter in water. It is a widely used parameter to assess the level of organic pollution in water bodies.
Statement 2: High value of BOD indicates that water is highly polluted by organic matter.
The second statement is also correct. A high BOD value indicates that there is a large amount of organic matter present in the water, which in turn indicates high pollution levels. When organic matter enters the water, microorganisms start breaking it down through the process of decomposition. During this process, microorganisms consume oxygen, leading to a decrease in the dissolved oxygen levels in the water. Therefore, a high BOD value indicates that there is a high demand for oxygen due to the presence of organic pollutants.
Explanation:
The first statement explains what 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. This means that BOD measures the oxygen requirement for the complete breakdown of organic matter in water.
The second statement builds on the first statement by explaining that a high BOD value indicates high pollution levels. This is because a high BOD value indicates a large amount of organic matter present in the water, which implies higher pollution levels. As the microorganisms break down the organic matter, they consume oxygen, leading to a decrease in the dissolved oxygen levels in the water. High levels of organic pollutants can result in the depletion of oxygen, making it difficult for aquatic organisms to survive.
Therefore, both statements are correct, but statement 2 is not the direct explanation of statement 1. Instead, statement 2 elaborates on the implications of a high BOD value, indicating high pollution levels caused by organic matter.
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