What is the amount of dissolved oxygen required in aerobic bacterial decomposition called?

The amount of dissolved oxygen required in aerobic bacterial decomposition is referred to as biochemical oxygen demand (BOD). BOD is a critical measure used to assess the amount of organic matter present in water that aerobic bacteria will consume. It reflects the oxygen needed by these microorganisms to decompose the organic material present in a sample over a specified period, typically five days at 20 degrees Celsius.

Measuring BOD is essential in environmental science and waste management because it helps determine the impact of wastewater or organic waste on aquatic ecosystems. A higher BOD indicates a greater amount of organic material present, which can deplete oxygen levels in water, potentially harming aquatic life.

In contrast, chemical oxygen demand (COD) measures the total oxygen required to oxidize all organic material in water, not just the biodegradable portion, while total organic carbon (TOC) quantifies all organic carbon without specifying whether it's biodegradable. The oxygen-reduction ratio does not specifically measure the oxygen demand from decomposition but generally relates to the balance of oxidizing and reducing agents in a system.