Waste biomass-derived organic matter for sustainable soil remediation: Enhancing heavy metal removal and eluent reuse in agricultural application.

Heavy metal contamination in agricultural soils, exacerbated by industrial and human activities, threatens food security and human health. While various remediation methods exist, their sustainability is limited by effectiveness, environmental impact, and cost constraints. Soil washing offers a cost-effective solution for permanent metal removal, yet challenges persist: (i) scarcity of eco-friendly and efficient washing agents, (ii) inadequate eluent purification/reuse strategies, and (iii) limited integrated in-situ remediation technologies. Dissolved organic matter (DOM) from waste biomass and its modified residues show promise as green, low-cost solutions for soil and eluent treatment. This review synthesizes global advances in heavy metal remediation, emphasizing novel washing agents and understudied eluent management. Aligned with green remediation principles, we propose an in-situ combined solubilization and drainage system using DOM-based washing agents, coupled with eluent recycling, to address these gaps. Waste biomass-derived washing agents combined with integrated eluent purification and reuse may be a potential strategy for achieving scalable and environmentally friendly remediation of heavy metal contaminated agricultural soils. The findings aim to guide the development of sustainable, problem-oriented remediation technologies.