Mechanochemical force-driven stepwise activation and reconstruction of carbon-ash in coal-based solid wastes and pollutant removal

As a common solid waste in the coal chemical industry, coal gasification fine slag (CGFS) requires resource utilization, which is an inevitable requirement for the clean development of coal chemical enterprises. In this work, composite materials (M x CGFS-800-H) were fabricated from CGFS as the raw material via a desilication-reconstruction-pore expansion strategy using different activators. Characterization results showed that adsorption sites and abundant pore structures (with a specific surface area of 221.73 m 2 /g) were provided for the catalyst by residual carbon; nepheline formation was promoted by NaOH, iron species were stabilized, and aluminum elements were removed during acid washing, ensuring that iron species were transformed into active sites. Specifically, M N1 CGFS-800-H activated by NaOH exhibited excellent performance in activating peroxymonosulfate (PMS) for the degradation of bisphenol A (BPA). The carbon-ash synergy enabled M N1 CGFS-800-H to remove 99.60 % of BPA within 60 min, with a mineralization degree reaching 52.85 %. Functional groups (C=O) and iron species were responsible for the generation of reactive oxygen species (ROS), thereby facilitating the degradation of pollutants. The M N1 CGFS-800-H/PMS system showed strong resistance to saline ions interference and was highly reusable. This study provided a new method for the synergistic utilization of carbon and ash in CGFS.