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

The degradation of sodium p-cumenesulfonate (SCS) by electrochemical, photochemical, and photoelectrochemical methods in aqueous solution of NaClO(4), NaCl, and NaClO has been studied. It was found that as a result of NaClO(4) electroreduction and photodecomposition, the ions Cl(−) and ClO(3) (−) are formed. These ions undergo transformations into radicals, mainly Cl(•), Cl(2) (•−), ClO(•−), ClO(2) (•−), and ClO(3) (•−), 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 ClO(4) (−) cannot be adequate without taking into consideration the reduction of ClO(4) (−) to Cl(−) and ClO(3) (−). 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 NaClO(4) 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.