Acid-base synergistic activation of coal gasification fine slag into hierarchical porous carbon for enhanced Cr( vi ) adsorption and reduction

; nevertheless, considerable removal efficiency was maintained in multi-ion systems, and 63.32% of the initial performance was retained after five regeneration cycles. Mechanistic analyses revealed that Cr(vi) removal was governed by synergistic processes involving pore-filling enrichment, electrostatic attraction and hydrogen bonding, as well as surface redox reactions and complexation. These findings demonstrate the feasibility of valorizing CGFS as a low-cost precursor for advanced adsorbents in heavy-metal wastewater remediation.