Determination of the chemical oxygen demand (COD) using a copper electrode: a clean alternative method

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A clean alternative method for the determination of chemical oxygen demand (COD) was developed using a copper electrode as an electrocatalytic sensor. The measuring principle is based on oxidation current of organic compounds in the wastewater. The effects of important experimental conditions, such as electrolytic solution concentration and potential scan rate, on analytical performance have been investigated. Analytical linear range of 53.0-2,801.4 mg l(-1) COD with detection limit of 20.3 mg l(-1) COD was achieved. The procedure was successfully applied to the COD determination in wastewater from soft industries. The results obtained using the proposed method were in good agreement with those obtained using the conventional (i.e., dichromate) COD method. In this fashion, the COD value of a sample can be determined in a simple, rapid, accurate manner, and the end products do not contain toxic metals.