Question
Biochemical Oxygen Demand (BOD) value can be a measure of water pollution caused by the organic matter. Which of the following statements is correct -
The correct answer is
Aerobic bacteria decrease the BOD value
Understanding BOD Measurement
Biochemical Oxygen Demand (BOD) measures the amount of dissolved oxygen needed by aerobic organisms to decompose organic matter in water. It's a key indicator of water pollution.
Role of Aerobic Bacteria
Aerobic bacteria are crucial for the BOD process. They consume organic pollutants, using dissolved oxygen in the water.
- The breakdown of organic matter by aerobic bacteria leads to the consumption of oxygen.
- This consumption is what BOD quantifies.
- As aerobic bacteria work, they reduce the organic load and thus the potential oxygen demand (BOD).
Evaluating the Statements
- Option 1: Incorrect. BOD measures aerobic decomposition, not anaerobic.
- Option 2: Correct. Aerobic bacteria decompose organic matter, consuming oxygen. This process reduces the potential BOD of the water.
- Option 3: While polluted water often has BOD value higher than 10 ppm, this describes a state, not the bacterial action measured by BOD.
- Option 4: Incorrect. Clean water has low BOD values.
Therefore, the action of aerobic bacteria leads to a decrease in the BOD value as they break down organic pollutants.
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Similar Questions
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Important Questions from Inorganic Chemistry
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$\text{NaCl} + \text{K}_2\text{Cr}_2\text{O}_7 + \text{H}_2\text{SO}_4 \rightarrow \text{A} + \text{KHSO}_4 + \text{NaHSO}_4 + \text{H}_2\text{O}$
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