Redox regulation for sustainable water purification and risk management

Abstract

Sustainable detoxification and advanced treatment of toxic organic pollutants (TOPs) in wastewater are essential for water reclamation and ecosystem security. Although biological treatment is a low-carbon and eco-friendly approach for TOPs degradation, its effectiveness is often limited by the high toxicity and recalcitrance of TOPs. Oxidative and reductive reactions can degrade TOPs according to their intrinsic redox potentials. However, conventional biological or chemical oxidation treatment often fails to efficiently or purposefully cleave key functional groups, which leads to unsatisfactory performance of biological reactions or excessive chemical oxidation costs. This perspective proposes redox regulation as a strategy to moderately catalyse the oxidation or reduction of TOPs and thereby generate low toxicity and increased biodegradable intermediates, which will improve subsequent biological treatment. We summarize strong redox regulation techniques, including advanced oxidation and reduction processes, and weak redox regulation through low-energy electrical potential, along with the corresponding mechanisms and applications. Additionally, we explore the integration of redox regulation with biological treatment, either in a sequential mode or in situ. This study emphasizes the need for future research to focus on targeted and durable catalytic detoxification processes and to optimize balancing the carbon footprint, process control, operational efficiency, and economic feasibility. By integrating chemical reactions with microbial metabolism, redox regulation has the potential to transform wastewater treatment from isolated process optimization to a holistic approach. This perspective advocates for innovation of conventional wastewater detoxification technologies to achieve sustainable water purification and ecological risk control.