Which of the following is a common method used to measure BOD?

The measurement of Biochemical Oxygen Demand (BOD) is commonly performed using a method that involves a BOD bottle and incubation. This method allows for the assessment of the amount of oxygen consumed by microorganisms as they decompose organic matter in a water sample over a specified time period, usually five days at a controlled temperature of 20°C.

This process begins by filling a BOD bottle with a diluted sample of wastewater, sealing it to prevent gas exchange, and then incubating it in a dark environment. The decrease in dissolved oxygen (DO) levels in the sample during the incubation period is measured. The difference between the initial and final DO readings provides the BOD value, indicating the level of organic pollution in the water.

Utilizing this specific method is pivotal for understanding the impact of wastewater discharges on receiving water bodies, as it reflects the oxygen demand that could affect aquatic life. While other options like spectrophotometers, filtration methods, or manometers have their applications in water quality measurement, they do not specifically measure BOD in the established and standardized way that the BOD bottle method does.