Designing and modeling of a novel electrolysis reactor using porous cathode to produce H2O2 as an oxidant

Abstract

The entry of toxic organic pollutants and resistant to biodegradation has increased the concern about human health. The use of advanced oxidation (AO) processes to degrade these pollutants has been developing. One of the AO processes is based on the use of hydrogen peroxide in removing resistant organic pollutants.This study aimed to develop a new reactor capable of producing H2O2 in the solution. Therefore, a porous electrode made of stainless steel with the capability of air injection in the electrode center was used. The 30 cm rod graphite electrodes were also used as an anode electrode in a 4000 ml reactor. The effects of variables, including current density (30–40 mA/cm2), time (10–30 min), and electrolyte concentration (12–17 mM/L) on the amount of H2O2 production were evaluated by Box behenken design under response surface methodology using Design expert software. The results of this study showed that H2O2 can be produced at the electrode surface of porous cathode under optimal conditions of 36 mA/cm2 current density, 16 mM/l electrolyte concentration, in 23 min, and in the amount of 34 ppm. Using a porous cathode electrode causes the maximum contact among the solution, water, and air, and increases the production of H2O2.The release of resistant organic compounds to the waste water is a serious problem to the environment. By the application of the Electro-oxidation (EO)reactor with the ability to produce H2O2, this issue is resolved. Furthermore, this technique is applied for non-selective degradation of the toxic organic compounds. • The electro-oxidation process is a useful method for destruction of persistent organic matter from wastewater. • Due to use of porous cathode in this method, contact between the electrode and the sewage is at its maximum level which increases the efficiency and speed of sewage treatment. • This method can produce H2O2 as a high potential oxidant that can reduce persistent organic properties of sewage and make the wastewater suitable for biological treatment. Method name: Advanced Oxidation Process (AOP), Electro-oxidation (EO), Electrochemical Oxidation Processes (EOP), Keywords: Box Behnken design, Electro-oxidation process, Hydrogen peroxide, Modeling, Porous electrode