半胱氨酸-β-环糊精同时解吸去除复合污染土壤中氰草津和镉的研究

在β-环糊精（β—CD）的基础上，通过β-环糊精与半胱氨酸的反应获得一种新型的半胱氨酸-β-环糊精（CCD）。红外结果表明，CCD在保留β-CD原有空腔结构的同时还增加氨基、羧基及巯基，CCD能同时实现对氰草津的包结作用和镉的配位作用。增溶试验研究表明，CCD对氰草津和碳酸镉有明显的增溶效应，10g／LCCD对氰草津的增溶倍数可达21倍；碳酸镉的表观溶解度随着CCD浓度的增加而增加，当CCD浓度为10g/L时，水溶液中镉离子的浓度为599mg／L。10g／LCCD对复合污染土壤中氰草津和镉解吸去除率分别为81％和89％，解吸过程符合准二级动力学规律，解吸动力学常数分别为0．00493和0．01010g／（mg·min）。pH的降低和CCD初始浓度的增加有利于复合污染土壤中氰草津和镉的解吸。

Simultaneous Desorption Removal of Cyanazine and Cadmium from Co-contaminated Soils with Cysteinecyclodextrin

On the basis of 13-cyelodextfin, a novel cysteine-β-cyclodextrin （CCD） was synthesized by the reaction of 13-cyclodextrin with cysteine. The infrared spectra demonstrated that the original inner cavity was kept in CCD and amino, carboxyl and sulfhydryl groups were added. CCD can Simultaneously complex cyanazine and cadmium. The results from solubilization experiments showed that CCD has obvious solubiliza- tion for eyanazine and cadmium carbonate. The solubility of cyanazine in 10 g/L of CCD was enhanced about 21-fold, and the apparent aque- ous solubilities of cadmium carbonate are also obviously increased with increasing CCD concentration, when the concentration of CCD reached 10 g/L, the aqueous cadmium concentration was 599 mg/L. At concentration of 10 g/L, CCD has a removal efficiency of 81% and 89% for eyanazine and cadmium, respectively, from the combined contaminated soil. The desorption process of CCD for cyanazine and cadmium from co-contaminated soil followed the pseudo-second-order kinetic model, the desorption kinetic constants of cyanazine and cadnfium in soils were 0. 004 93 and 0.010 1 g/（ mg. min）, respectively. Low pH and high CCD concentration were beneficial to the desorption of cyanazine and cadmium from co-contaminated soil.