How is the COD value typically expressed?

The Chemical Oxygen Demand (COD) value is a crucial parameter in wastewater treatment, as it indicates the amount of oxygen that will be consumed by the chemical oxidation of organic and inorganic compounds in water. This measurement is typically expressed in milligrams per liter (mg/L), which provides a clear quantification of the concentration of pollutants present in the water.

Expressing COD in milligrams per liter allows for a standardized way to compare levels of organic matter across various samples and conditions, which is essential for assessing water quality and the effectiveness of treatment processes. This unit is particularly useful in scenarios where precise concentrations are necessary for regulatory compliance and operational monitoring.

The other measurement units, while relevant in different contexts (liters per second relates to flow rates, grams per cubic meter is not commonly used for COD, and percentage concentration might apply in some chemical analyses), do not align with the standard method of expressing COD values in wastewater treatment practices.