Abstract: Cr(Ⅵ) was quantitatively adsorbed by 4-amino-1,2,4-triazole resin(4-ATR) in a medium of pH=1,but Cr³⁺ almost could not be adsorbed. The separation coefficient βCr (Ⅵ)/Cr³⁺ is as high as 5.52×10³. The statically saturated sorption capacity is 179.4mg Cr(Ⅵ)/gresin [3.45 mmol Cr(Ⅵ)/g resin]. Cr(Ⅵ) adsorbed on 4-ATR can be reductively eluated by 5mol/L HCL. The sorption rate constants determined under various temperatures wereK_21·C=1.59×1O^-3S^-1,K_25·C=1.87×10^-3S^-1 and K_30·C=2.2×10^-3S^-1,respectively. The apparent activation energy of sorption E_a is 26.26kJ/mol.The thermodynamic parameters of sorption,enthalpy ΔH₂₉₈,freeenergy ΔG₂₉₈,and entropy ΔS₂₉₈ of sorption (4-ATR) for Cr(Ⅵ) are 86.16, -15.1 kJ/mol,and 339.8 J/mol.K,respectively.Coordination molar ratio of Cr(Ⅵ)to is 1:1. The sorption mechanism shows that the nitrogen atoms of the functional group of 4-ATR coordinated with Cr(Ⅵ) to form coordination bond. The 4-ATR can be used in the separation of Cr(Ⅵ) from the waste electroplating water. The percentage of recovery of chromium is 95.7%.

Key words: aminotriazole, chromium ion, adsorption