Electrochemical, Photochemical, and Photoelectrochemical Treatment of Sodium p-Cumenesulfonate

Abstract

The degradation of sodium p-cumenesulfonate (SCS) by electrochemical, photochemical, and photoelectrochemical methods in aqueous solution of NaClO4, NaCl, and NaClO has been studied. It was found that as a result of NaClO4 electroreduction and photodecomposition, the ions Cl− and ClO3 − are formed. These ions undergo transformations into radicals, mainly Cl•, Cl2 •−, ClO•−, ClO2 •−, and ClO3 •−, due to electrochemical and photochemical reactions. It was shown that the interpretation of results of the studies over mineralization processes carried out in the presence of ClO4 − cannot be adequate without taking into consideration the reduction of ClO4 − to Cl− and ClO3 −. Therefore, previous works presented in the literature should be rediscussed on the basis of the new data. Photoelectrochemical mineralization of substrate in NaCl solution at the concentration of 16 mmol L−1 is comparable with the efficiency of the reaction in NaClO4 solution containing more than 8 mmol L−1 of NaClO. Total SCS mineralization was obtained in the photoelectrochemical reactor with a UV immersion lamp with a power 15 W in the period of 135 min and current intensity of 350 mA. In such conditions, the power consumption was about 1.2 kWh per g of TOC removed.