Desalination and Water Treatment

Abstract

In this study, the electrochemical deposition of gold (Au) onto graphite has been performed under different deposition potential conditions. These Au particles electrodeposited on the graphite were used as cathode for O2 electrochemical reduction and H production in acidic solution, and the hydrogen peroxide (H2O) electrogenerated on graphite modified by gold particles was used in electro-Fenton process. Results show firstly that the O2 cathodic reduction on gold particles electrodeposited on the graphite electrode in acidic medium with two well-defined reduction waves at −300 mV/SCE and −1,300 mV/SCE; those waves indicated reduction of two O2 electrons to H2O. Secondly, the optimal cathodic potential condition for H2O 22 generation on cathode modified was −300 mV and unmodified one was −500 mV/SCE. The electrolysis time, dissolved oxygen level, magnetic stirring, and pH were systematically studied; the hydrogen peroxide production increased with the aeration and electrolysis time and then became stationary after 2 h of electrolysis. The maximum Haccumulation increased up to 60 mg/L with air compressed, at −300 mV. Optimized parameters (potential, oxygen level, and concentration of ferrous ions) were also applied to incinerate the Belgard EV2030 sodium salt of polycarboxylic acid. The incineration efficiency onto optimized parameters shows that 74% of Chemical oxygen demand was incinerated in the modified electrode that confirms the positive gold modification effect onto the performance.