Investigation on the Rectification of salt concentration in COD measurement

Abstract

COD is significantly affected by the salt content of the test solution, so pretreatment using silver compounds such as silver nitrate and silver sulfate is commonly used. However, rising international prices for precious metals have made the cost of silver use a problem. Since it is known that salt concentration has a linear effect on COD measurements, we investigated the possibility of eliminating the silver pretreatment by correcting for salt content using this relationship.