Proton-gradient-regulated biomass microfluidic FeNiCu/CW electrodes enabling integrated decontamination and deionization of hypersaline landfill leachate

Hypersaline landfill leachate remains difficult to treat because high ionic strength screens interfacial electric fields and destabilizes coordinated contaminant removal and desalination. A proton gradient regulated integrated decontamination and deionization system (IDDS) is presented using biomass derived FeNiCu carbonized wood microfluidic electrodes. A programmable dual to single electrolysis sequence serves as the carrier of proton regulation, generating a dynamic H⁺ field that reconstructs the electric double layer within confined microchannels and converts bulk screened electrolysis into compact layer gated interfacial control. In the dual cell stage, proton enrichment compresses the double layer and sustains an oxidation selective interface that concentrates the effective oxidative flux within the •OH and SO₄^-• manifold while suppressing chlorine radical branching by stabilizing chloride predominantly in nonradical counter ion states. After membrane removal, relaxation of the proton field enables bulk ion repartitioning, followed by alkaline inversion that locks divalent ions through irreversible sinks including hydroxide precipitation with concomitant anion co capture, completing stepwise desalination. Treating real leachate, the IDDS achieves 82% COD removal, 99.9% NH₄⁺-N removal, and approximately 90% conductivity reduction at a low specific energy consumption of 0.058 kWh m^-3. Proton gradient gated interfacial reconstruction, implemented through staged electrolysis in microfluidic biomass electrodes, therefore provides a general blueprint for economically scalable purification of hypersaline wastewaters without chemical dosing.