Fig. 3. pH-dependent leaching profiles of heavy metals from the carbonated air pollution control (APC) residues based on experimental (, , x) and calculated results (GB/EN-C and TCLP-C are the results without input of CO₃^2–; GB/EN-C-1 and TCLP-C-1 are the results with input of 0.15 and 0.075 mol L^–1 CO₃^2–, respectively; GB/EN-C-2 and TCLP-C-2 are the results of pure heavy metals carbonates). EN, European shake test (EN 12457-3); GB, Chinese method for determining the leaching toxicity of solid waste (GB 5086.1-1997); TCLP, Toxicity Characteristic Leaching Procedure.