A measure of the total oxygen demand of water under chemical oxidation, including non-biodegradable organics. Used as a fast, automatable wastewater quality proxy.
COD (chemical oxygen demand) measures the total oxygen demand of a water sample under chemical oxidation conditions, including organics that BOD does not capture. COD is faster to measure than BOD and is used for routine wastewater plant monitoring. The ratio of BOD:COD indicates biodegradability of the load — important for predicting treatment performance and downstream odor potential.