The Biochemical Oxygen Demand (BOD) of water is a measure of:
- A Total dissolved solids in water
- B Chemical oxygen used to oxidize all organic and inorganic matter
- C Amount of oxygen required by microorganisms to decompose organic matter in water under aerobic conditions over 5 days at 20°C ✓
- D Dissolved oxygen level at the saturation point
Correct answer: C. Amount of oxygen required by microorganisms to decompose organic matter in water under aerobic conditions over 5 days at 20°C
Explanation
BOD (Biochemical Oxygen Demand) measures the amount of dissolved oxygen consumed by microorganisms during the aerobic biological decomposition of organic matter in water over 5 days at 20°C (BOD5). High BOD indicates high organic pollution load and low water quality. BIS standard for drinking water: BOD should be 0 mg/L (not detectable). BOD differs from Chemical Oxygen Demand (COD), which measures both biodegradable and non-biodegradable organic compounds.
Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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