A research team led by the University of California, Berkeley and Lawrence Berkeley National Laboratory has developed a low-cost, autonomous electrochemical advanced oxidation process (AOP) that targets trace organic contaminants and simultaneously disinfects water—without added chemicals. The approach is designed to overcome long-standing barriers to deploying AOPs in small, distributed systems such as household recycling, industrial wastewater treatment, and groundwater remediation.
The project addresses limitations of conventional treatment methods. Sorbent-based systems like activated carbon can struggle with polar, low molecular weight contaminants (e.g., 1,4-dioxane, 1,2,3-trichloropropane) and create spent media disposal challenges. Meanwhile, the widely used UV/H₂O₂ AOP often proves impractical at small scales due to reagent replenishment needs and the cost and fouling risk of submersed UV lamps. The team’s goal is to deliver “pipe parity” for non-traditional water sources by replacing multiple unit processes with a compact, electrified treatment cartridge.
At the heart of the innovation is a three-electrode system that generates and activates hydrogen peroxide in situ while directly oxidizing contaminants. A gas-diffusion cathode produces H2O2 from oxygen, a stainless-steel mesh cathode that converts H₂O₂ into hydroxyl radicals for powerful oxidation, and a boron-doped reduced graphene oxide (BDrGO) anode provides direct electrochemical oxidation. The team first optimized each step individually—anodic oxidation, O₂ reduction to H₂O₂, and H₂O₂ activation—before integrating them into a single flow-through treatment module.
Laboratory results show the integrated cartridge can exceed 90 percent contaminant removal in a single pass under optimized conditions. Key performance features include high Faradaic efficiency, complete utilization of generated H₂O₂ (no residual peroxide in the effluent), and self-regulating pH—an acidic pH prior to the final cathode favors hydroxyl radical generation, eliminating the need for external pH adjustment. Importantly for real-world use, testing indicated no chlorinated byproducts above regulatory standards in simulated surface water, addressing a common concern with oxidation processes.
The researchers also report strong electrode stability. Gas-diffusion cathodes maintained performance even in the presence of scaling: magnesium ions and hydrogen evolution promoted formation of a mineral layer that did not reduce efficiency, with hydrogen evolution creating channels that preserved permeability. The BDrGO anode helped suppress chlorinated byproduct formation during electrooxidation, while the stainless-steel cathode drove much of the contaminant removal by activating H₂O₂ to hydroxyl radicals. Optimization found that operating the gas-diffusion cathode at 4 mA increased H₂O₂ production and overall removal compared to 2 mA, and that running the stainless-steel cathode at 2 mA maximized hydroxyl radical formation without diverting H₂O₂ to water.
Cost and scalability figures position the system as a compelling alternative to under-sink reverse osmosis (RO). The prototype’s capital cost is about $309–$310—on par with common RO units—and projected operating costs are low, with energy at roughly $0.0325 per cubic meter and annual maintenance in the range of $67–$100. The cartridge avoids ion-exchange membranes and uses only electricity to drive treatment, enabling a zero-chemical-input design suited to distributed applications.
Beyond the lab-scale prototype, the project advances NAWI’s objectives in materials and manufacturing by aiming for robust, long-lasting electrodes and autonomous operation that adapts to variable influent water matrices. If successful, the technology could intensify and simplify treatment trains at small scale, helping communities tap non-traditional water resources where conventional systems are impractical.
For more on the project, view the project poster and research brief. You can also view this previously recorded webinar highlighting the project.