Electrochemical artificial humification for sustainable waste biomass valorization and soil remediation.

Abstract

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.