BOD (Biochemical Oxygen Demand) is a measure of the amount of oxygen required by microorganisms to break down organic compounds in a water sample. BOD is measured in mg/L and is an important parameter for assessing water quality, particularly with regard to organic pollution in wastewater. In practice, the BOD value is often used to monitor the efficiency of biological wastewater treatment processes. A high BOD value indicates a high organic load, which can reduce the oxygen content in natural waters and endanger aquatic ecosystems.