Valorizing Coal Gasification Fine Slag through a ‘Division of Labor’ Mechanism for Sustainable Soil Remediation

Abstract

Addressing the dual challenges of industrial waste and soil contamination, this study explores the valorization of coal gasification fine slag (CGFS) as a functional soil amendment for heavy metal immobilization. In cherry tomato experiments, CGFS application significantly improved soil health and reduced heavy metal translocation, cutting fruit lead (Pb) by 64% and eliminating cadmium (Cd) to ensure food safety. We uncovered a novel ‘division of labor’ mechanism where distinct morphological components of CGFS selectively immobilize different metals: aluminosilicate spheres preferentially capture Cd, while carbon/iron-rich structures sequester Pb. This work demonstrates a scalable, low-cost ‘waste-to-resource’ strategy, providing a scientific blueprint for circular economy-driven soil remediation and the valorization of complex industrial by-products.