Chemical Oxygen Demand
COD is one of the most important water quality parameters. COD is defined as the ammout of dissolved oxygen required in water to oxidize the chemical organic materials present. It is expressed in milligrams per litre (mg/L).
COD can measured using a reagent based test and a spectrophotometer or inderectly using UV254 and treating it as a surrogate. The latter does not rquire consumables
High COD levels can lower dissolved oxygen in water. Thus leading to a negative environmental effect and potential legal judgments. COD is one of the most heavily regulated parameters when discharging water.