What does biological oxygen demand (BOD) measure?

Biological oxygen demand (BOD) specifically measures the amount of oxygen that microorganisms require to decompose organic matter present in water over a specified time period. This is a critical parameter in evaluating the organic pollution level in water, as it indicates the extent of the biological activity taking place when organic material is present.

A higher BOD value suggests that there is a greater amount of organic matter that needs to be decomposed, which in turn signifies poorer water quality and a higher potential for oxygen depletion in aquatic environments. Conversely, lower BOD values indicate cleaner water with less organic material needing microbial breakdown, which generally results in healthier aquatic ecosystems.

Understanding BOD is fundamental for sewage treatment workers, as managing and reducing BOD levels is crucial for effective wastewater treatment and ensuring that treated effluent released into the environment does not harm local waterways.