Electrochemical artificial humification for sustainable waste biomass valorization and soil remediation

Waste biomass valorization is critical for sustainability. In nature, biomass is converted into humic substances via humification, a key component of global biogeochemical cycles. Here, authors develop a rapid electrochemical artificial humification (EAH) method: unlike natural and microbially mediated humification which take days to years, EAH matures in 60 minutes. Mechanistically, biomass degrades, with quinone-like radicals generated at the anode and H* at the cathode driving primary amine formation, and these intermediates undergo polymerization to form macromolecular artificial humic-like substances (AHLS) whose molecular, elemental and physicochemical traits resemble natural humic substances (NHS). AHLS shows potential as slow-release fertilizers and oxidizing agents, with uses in saline-alkali soil remediation, pollutant removal and nutrient slow release. Techno-economic analysis highlights EAH’s advantages in land use efficiency and short-distance transportation which makes it particularly suitable for land-scarce megacities, while life cycle assessment shows it outperforms landfilling and composting in mitigating greenhouse effects and acidification. This work advances waste-to-resource tech, offers soil fertility and environmental strategies, and meets the core need for scalable, circular sustainability solutions. Okara, a major by-product of soybean processing, is generated at an estimated 140 million tonnes annually, with landfill disposal contributing to pollution and the loss of valuable organic resources. Conventional aerobic composting is land-intensive, slow, and associated with substantial greenhouse gas emissions and strict operational requirements. Here, the authors develop an Electrochemical Artificial Humification (EAH) system that requires 15-fold less land, improves reaction efficiency, and produces valueadded products functioning as slow-release fertilizers, soil restorers, and sustainable oxidants. This technology supports sustainable organic biomass waste recycling.