COD reagent is the amount of oxidant consumed when treating water samples with a certain strong oxidant under certain conditions. It is an indicator of the amount of reducing substances in water. The reducing substances in water include various organic compounds, nitrites, sulfides, ferrous salts, etc. But the main thing is organic matter. Therefore, COD reagents are often used as indicators to measure the content of organic matter in water. The higher the chemical oxygen demand, the more severe the pollution of organic matter in the water body.

COD(ChemicalOxygenDemand), Chinese name: Chemical Oxygen Demand, is a chemical method used to measure the amount of reducible substances that need to be oxidized in water samples. The oxygen equivalent of substances that can be oxidized by strong oxidants in wastewater, wastewater treatment plant effluent, and polluted water.