What does chemical oxygen demand (COD) measure?

Chemical oxygen demand (COD) measures the total quantity of oxygen required to oxidize both organic and inorganic matter in water through chemical processes. This parameter is crucial in wastewater treatment because it provides an indication of the pollution load of the wastewater. A higher COD means that a greater amount of oxygen is needed to break down the contaminants, which can impact the performance of treatment processes and the ecosystem of receiving waters if not managed properly.

COD is particularly useful in evaluating the effectiveness of wastewater treatment facilities in removing organic pollutants and assessing the overall quality of water. By determining the COD, operators can make informed decisions about treatment efficiency and necessary adjustments to manage the wastewater effectively. Understanding COD helps in maintaining environmental standards and ensuring the safety of water bodies into which treated effluent is discharged.