Optimization of electrocoagulation for green hydrogen production and sustainable wastewater treatment: a critical review

Abstract

Electrocoagulation (EC), initially conceived for the treatment of wastewater, is currently the focus of concerted efforts to enhance its energy efficiency, sustainability, and green hydrogen production. The latest developments in the technology are examined in this review, including the fundamentals of EC, its primary applications, key operational parameters, and challenges. There have been notable advancements in reactor design – particularly continuous-flow reactors and single-channel CFSC – as well as in electrode configuration, aiming to improve pollutant removal efficiency and reduce energy consumption. Furthermore, the integration of advanced strategies such as photo electrocoagulation, alternating current (AC), pulsed current (APC), and automatic electrode cleaning contributes to reducing electrode passivation and extending system longevity. EC thus emerges as an attractive technology in the context of the energy transition, notably due to the simultaneous recovery of hydrogen and its compatibility with intermittent renewable energy sources (solar, wind). However, challenges remain, including the intermittency of these energies and the initial implementation costs. Recent research also highlights the benefits of combining EC with other emerging technologies. When associated with techniques such as electrooxidation, photocatalysis, and the coupling of reverse electrodialysis (RED) with EC, there is a significant increase in both the production and purity of hydrogen. This work outlines EC's role as a future-ready technology at the water – energy nexus by showcasing its potential as an independent, low-carbon, and circular solution for sustainable water treatment and by providing a roadmap that connects technological advancements in EC with integration of renewable energy sources and hydrogen recovery.

Topics & Concepts