Question

BOD is a measure of

• A. Organic pollution
• B. Biological pollution
• C. Inorganic pollution
• D. Chemical pollution

Hint:

Water Quality Pollution Indices:
BOD (Biochemical Oxygen Demand) = BIODEGRADABLE ORGANIC POLLUTION.
COD (Chemical Oxygen Demand) = Total (Biodegradable + Non-biodegradable) oxidizable matter.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Sanitary water quality analysis: Biochemical Oxygen Demand (BOD) quantifies the mass of dissolved oxygen consumed by aerobic heterotrophic microorganisms to biochemically oxidize biodegradable organic matter.
Key Formula or Approach:
\[ \text{BOD}_5 \text{ (mg/L)} = \frac{\text{DO}_0 - \text{DO}_5}{P} \quad [\text{Direct Measure of Biodegradable Organic Load}] \]

Step 2: Detailed Explanation:
In aquatic environmental science and wastewater management:
- Biochemical Oxygen Demand (BOD) (standardly measured as 5-day BOD at $20^\circ ext{C}$, $\text{BOD}_5$):
- Measures the amount of dissolved molecular oxygen required by aerobic heterotrophic microorganisms to decompose and stabilize the biodegradable Organic Pollution (organic matter/waste) present in a water sample.
- High BOD values ($> 10 - 50\text{ mg/L}$) indicate severe organic contamination (untreated sewage, food processing waste, feed runoff), resulting in rapid oxygen depletion and fish kills.

Step 3: Final Answer:
Thus, BOD is a measure of Organic pollution, corresponding to option (A).