摘要
以脱乙酰度90%的壳聚糖(CTS)与硫氰酸铵和氯乙酸反应,合成了一种带有硫脲基和羧基双官能团的水溶性中间产物,再经戊二醛交联,制备了水不溶性的可用于处理含重金属废水的颗粒状树脂.用FTIR,SEM及比表面法对中间产物及颗粒状树脂进行了表征,表明—HN—C(S)—NH—CH2—COOH基团接枝到CTS链上并进行了交联.吸附实验表明,该化合物对Cu2+的吸附量(248mmol·g-1)比Ni2+(135mmol·g-1)高得多,这可能与离子的核电荷数和螯合体的配位相关.在两种金属离子的混合液中,该化合物对Cu2+的初始吸附选择性更强.吸附金属离子的树脂经3次盐酸洗脱再生后,吸附性能几乎没有下降.
A water-soluble intermediate bi-functional compound with thioureido and carboxyl groups was prepared by reacting chitosan (deacetyl degree 90%) with ammonium thiocyanate and chloroacetic acid. The optimum condition for reaction was obtained, which illustrated that the molar ratio for chotisan:ammonium thiocyanate:chloroacetic acid was 1.0∶1.2∶1.2,at 50℃ for 4h.The intermediate compound was then cross-linked by glutaraldehyde to prepare a novel water-insoluble cross-linked chitosan aiming to be used as an adsorbent for heavy metal wastewater treatment. The cross-linking reaction was conducted under the condition that the concentration of glutaraldehyde were 3.6%, at a reaction temperature of 40℃for 4h. Both the intermediate compound and the cross-linked grafted chitosan (CGCTS) were characterized by using FTIR, SEM and specific surface area measurement. The analysis results indicated that the—HN—C(S)—NH—CH_~2 —COOH groups had been grafted onto the chitosan molecular chain. A good adsorption capability of the synthesized porous chitosan for Cu^2+ (2.48 mmol·g^-1 )and Ni^2+ (1.35mmol·g^-1 ) was demonstrated respectively while a good adsorption selectivity for Cu^2+ in the mixed solution. Regeneration study of the synthesized porous CGCTS showed that there was no decrease in adsorption capability after three regeneration cycles.
出处
《环境化学》
CAS
CSCD
北大核心
2005年第2期209-212,共4页
Environmental Chemistry
基金
青岛市科技发展计划项目资助课题(021KJshn22).
