Enhanced in situ H2O2 electrosynthesis and leachate concentrate degradation through side-aeration and modified cathode in an electro-Fenton system.

ABSTRACT

The active graphite felt (GF) catalytic layer was effectively synthesized through a wet ultrasonic impregnation-calcination method, modified with CB and PTFE, and implemented in a pioneering side-aeration electrochemical in-situ H2O2 reactor. The optimal mass ratio (CB PTFE 14) for the modified cathode catalytic layer was determined using a single-factor method. Operating under optimum conditions of initial pH 5, 0.5 L/min air flow, and a current density of 9 mA/cm2, the system achieved a remarkable maximum H2O2 accumulation of 560 mg/L, with the H2O2 production capacity consistently exceeding 95 % over 6 usage cycles. The refined mesoporous structure and improved three-phase interface notably amplified oxygen transfer, utilization, and H2O2 yield. Side aeration led to an oxygen concentration near the cathode reaching 20 mg/L, representing a five-fold increase compared to the 3.95 mg/L achieved with conventional bottom aeration. In the final application, the reaction system exhibited efficacy in the degradation of landfill leachate concentrate. After a 60-minute reaction, complete removal of chroma was attained, and the TOC degradation rate surpassed 60 %, marking a sixfold improvement over the conventional system. These results underscore the substantial potential of the system in H2O2 synthesis and environmental remediation.