BOD and COD are two common measures of the organic pollution in wastewater. BOD (biochemical oxygen demand) measures the amount of oxygen consumed by microorganisms as they break down organic matter, while COD (chemical oxygen demand) measures the amount of oxygen required to oxidise organic matter chemically. Both BOD and COD are important indicators of the strength and treatability of wastewater.

In wastewater treatment, the goal is to reduce the levels of BOD and COD in the wastewater to acceptable levels before discharging it into the environment. Enzymes can be useful in this process by breaking down complex organic compounds into simpler compounds that can be more easily processed by microorganisms in the treatment system.

Enzymes can also be used in pre-treatment processes, such as primary sedimentation and screening, to break down larger organic particles and reduce the overall strength of the wastewater before it enters the biological treatment system.