What process is used to determine the chemical oxygen demand (COD) levels of a sample?

The process used to determine the chemical oxygen demand (COD) levels of a sample is oxidation. In this context, COD measures the total quantity of oxygen required to chemically oxidize organic and inorganic matter present in the water sample. During the COD test, a sample is treated with a strong oxidizing agent, such as potassium dichromate, in the presence of sulfuric acid. This chemical reaction converts the organic matter in the sample into carbon dioxide and water, effectively quantifying the amount of oxygen that would be needed to achieve complete oxidation.

This measurement is important because it provides an estimate of the organic pollutant load in wastewater, which is crucial for environmental monitoring and treatment processes. Understanding the COD levels helps wastewater treatment facilities determine the appropriate treatment methods required to remove contaminants and ensure the water is safe to discharge or reuse.