Prospects of Electrochemical Technologies to Reduce Chemical Input in Wastewater Reuse

Potable water reuse is becoming increasingly attractive in order to address global water scarcity. However, current advanced treatment trains that typically include reverse osmosis (RO), ultraviolet (UV)/H2O2 advanced oxidation, and chlorine disinfection processes are chemical-intensive, leading to high operational costs and potential environmental risks. In this Perspective, we explored the potential of integrating electrochemical processes into potable reuse systems as chemical-free alternatives. A variety of electrochemical processes are categorized based on their potential locations in the advanced treatment train, which include electrochemical softening for membrane fouling control, electrochemical H2O2 production for advanced oxidation processes, electrochemical dehalogenation for disinfection byproducts (DBPs) removal, and electrochemical chlorination for water disinfection. We summarize the advantages and challenges associated with each application. The energy cost of these processes was estimated to range from ∼$ 0.062 to $ 0.804 m–3, with electrochemical softening being the highest due to the requirement of generating highly concentrated OH–. To enhance energy efficiency, future research needs to focus on improving electrode materials and optimizing system operation. Additionally, the integration of electrochemical systems with renewable energy has the potential of further reducing energy demands and minimizing environmental impacts.