摘要
4-氨基-三氮唑树脂(4-ATR)对Cr(Ⅵ)的吸附在pH=1时最佳,Cr^(3+)基本不被吸附。两者分离系数β_(CrVI/Cr^(3+)=5.52×10~3.静态饱和容量为179.4mg Cr(Ⅵ)/g树脂。用5mol/L HCl能还原洗脱。测得不同温度下的吸附速率常数k_(21·c)=1.59×10^(-3)S^(-1)、K_(25·c)=1.87×10^(-3)S^(-1)、K(30·c)=2.2×10^(-3)S^(-1);表观吸附活化能E_a=26.26kJ/mol;吸附热力学函数ΔH=6.16kJ/mol,ΔG^(298)=-15.1kJ/mol,ΔS^(298)=339.8J.mol·K.吸附机理表明4-ATR功能基上的N与Cr(Ⅵ)发生配位键合,配位摩尔比为1∶1.利用此树脂处理含Cr(Ⅵ)电镀废水,铬回收率可达95.7%。
Cr(Ⅵ) was quantitatively adsorbed by 4-amino-1,2,4-triazole resin(4-ATR) in a medium of pH=1,but Cr^(3+) almost could not be adsorbed. The separation coefficient βcr (Ⅵ)/Cr^(3+) is as high as 5.52×10~3. 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^(-3)S^(-1),K_(25°)C=1.87×10^(-3)S^(-1) and K_(30°)C=2.2×10^(-3)S^(-1),respectively. The apparent activation energy of sorption E_2 is 26.26kJ/mol.The thermodynamic parameters of sorption,enthalpy ΔH_(298),freeenergy ΔG_(298),and entropy ΔS_(298) 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.%.
出处
《应用化学》
CAS
CSCD
北大核心
1992年第6期31-35,共5页
Chinese Journal of Applied Chemistry
基金
国家自然科学基金
关键词
铬
吸附
4-ATR
aminotriazole, chromium ion, adsorption
