羧基化杯[6]芳烃磷氧衍生物(HHPHC)对Cu^(2+)、Ni^(2+)的萃取性能

Extraction of Cu^(2+) and Ni^(2+) with phosphorate derivates of carboxyl calix[6]arene(HHPHC)

合成了萃取剂羧基化杯[6]芳烃磷氧衍生物,即5,11,17,23,29,35-六羧基-37,38,39,40,41,42-六氧磷酸二乙酯杯[6]芳烃(HHPHC),并对其进行了红外表征,考察了溶液初始pH值、萃取时间、重金属离子初始浓度、萃取温度对HHPHC萃取重金属离子(Cu^(2+)、Ni^(2+))的影响。结果表明,HHPHC萃取Cu^(2+)和Ni^(2+)的最佳温度均为30℃,最佳pH值均为5.0,且15 min基本达到萃取平衡,适宜处理低浓度重金属废水。准二级动力学模型(R2>0.94)和Freundlich等温模型(R2>0.999)均可拟合其萃取过程,Gibbs自由能(ΔG0)和焓变(ΔH0)值均小于0,表明萃取反应是一个自发的放热反应。

A,5,11,17,23,29,35-hexacarboxy-37,38,39,40,41,42-hexaoxygen-diethyl phosphate calix[6]arene（ HHPHC） extractant was synthesized. IR spectroscopy was used to characterize the compounds. The effects of the pH,initial Cu^2＋and Ni^2＋concentrations,extraction time,and extraction temperature on the extraction of Cu^2＋and Ni^2＋using HHPHC were investigated. The results showed that the maximum extraction was attained under the following conditions： pH 5. 0,low initial Cu^2＋and Ni^2＋concentrations,an extraction time of15 min,and an extraction temperature of 30 ℃. The extraction of Cu（ Ⅱ） and Ni（ Ⅱ） onto HHPHC agreed well with the pseudo-second-order kinetic model（ R2 0. 94） and the Freundlich model（ R^2〉 0. 999）. Meanwhile,the change in enthalpy（ ΔH^0） was negative,indicating that the extraction reaction was exothermic.