Electro-oxidation process assisted by solar energy for the treatment of wastewater with high salinity

Industrial wastewaters characterized by its high content in organics and conductivity entails a challenge for conventional treatments due to its low biodegradability. Electro-oxidative processes have been successfully applied for the treatment of this kind of wastewaters achieving high organics and ammonia removal. The degradation process is executed mainly by electrochemically generated active chlorine species, as HClO and ClO- with E-0 = 1.49 V; and E-0 = 0.89 V, respectively. Under solar radiation, specifically at 313 nm, the formation of Cl center dot (E-0= 2.4 V) from ClO- is promoted, improving the oxidizing capacity of the process. In this work the combination of an electrochemical device with a solar photo-reactor has been evaluated aiming to increase the degradation rate per kWh(-1). Two different complex industrial wastewaters were tested, achieving higher organics degradation when electrochemical treatment was assisted by solar light. Toxicity reduction was also assessed and biodegradability enhanced and allowing its ulterior lower-cost biological treatment. (C) 2019 Elsevier B.V. All rights reserved.