Which of the following is estimated by measuring amount of BOD in a sample of water?

Oxygen consumption.

The correct answer is Option (1)- Oxygen consumption

Explanation:
The Biochemical Oxygen Demand (BOD) of wastewater is estimated by measuring the amount of oxygen consumed by microorganisms while decomposing the organic matter present in the water under aerobic conditions over a specific period . In simple terms, BOD tells us how much oxygen is needed by bacteria to break down the biodegradable organic substances in the water. A higher BOD value indicates a greater amount of organic pollution because more oxygen is required for decomposition. Therefore, BOD is not measured by the total organic matter or directly by the biodegradable organic matter, but rather by the oxygen consumed during the microbial degradation process.

The Biochemical Oxygen Demand (BOD) test is a measure of the amount of dissolved oxygen consumed by microorganisms in a water sample over a specific period. It is used as an indicator of organic pollution in water bodies. Organic pollutants, such as sewage, agricultural runoff, or industrial waste, introduce high levels of organic matter into the water. When these organic substances are decomposed by bacteria and other microorganisms, they consume oxygen from the water.

If the BOD of a water sample is high, it means that there is a significant amount of organic pollution present, requiring a higher rate of oxygen uptake by microorganisms to decompose the organic matter. The higher the BOD value, the greater the oxygen demand, indicating a higher level of pollution in the water.

 Final answer: Oxygen consumption