What does BOD measure in wastewater?

BOD, or Biochemical Oxygen Demand, measures the amount of dissolved oxygen that aerobic bacteria will require to decompose organic matter in a given sample of wastewater. This parameter is critical for assessing the organic pollution level in the water, as it provides insight into the potential impact of wastewater on the aquatic environment. High BOD values indicate a significant presence of organic matter that can consume oxygen, which is essential for the survival of aquatic life.

In the context of wastewater treatment, understanding BOD is vital for designing treatment processes that effectively reduce organic load before the effluent is discharged into the environment, ensuring that the remaining dissolved oxygen is sufficient to support aquatic organisms. Hence, the measurement focuses specifically on oxygen demand, reflecting the health and quality of the water.

Other choices, such as total suspended solids, concentration of nitrates, and pH level, relate to different characteristics of wastewater but do not provide the same insight into the oxygen requirements of microbial decomposition, making them less relevant to the concept of BOD.