Feasibility of integrated water treatment by chlorine oxidation and hydrogen production in water electrolysis systems using proton exchange membranes

초록

This study evaluates a proton exchange membrane water electrolysis (PEMWE) system for dual functionality in wastewater treatment and hydrogen production. Feedwater containing organic compounds-humic acid (HA), bovine serum albumin (BSA), and effluent organic matter (EfOM)-is supplied to the anode, with sodium chloride (1-10 g/L) added in situ to generate free chlorine oxidants. Linear sweep voltammetry shows that chloride addition increases overpotentials due to side reactions, yet free chlorine production rises proportionally. Dissolved organic carbon removal efficiencies reach 34.6 % for HA, 51.5 % for BSA, and 49.8 % for EfOM without notable loss of hydrogen yield. Excitation-emission matrix fluorescence spectroscopy indicates the breakdown of organic molecular structures, evidenced by decreases in humification, biological, and fluorescence indices. Size exclusion chromatography confirms the degradation of high-molecular-weight fractions in treated samples. Hydrogen production remains stable at 6.45-7.67 mL/min during 8 h of continuous operation despite a gradual 17 % voltage increase. These findings demonstrate PEMWE as a promising dual-purpose system for decentralized water treatment and energy generation.

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