钴/锰印迹半胱氨酸-壳聚糖对低浓度Mn^(2+)和Co^(2+)的选择性吸附

Selective Adsorption of Mn^(2+) and Co^(2+) in Dilute Solution by Cobalt/Manganese Imprinted Cysteine-chitosan

同时以硝酸锰和硝酸钴为印迹分子,采用溶胶凝胶法和反相悬浮法结合制备了交联壳聚糖微球(Co/Mn-CCTS),并通过与半胱氨酸的氨基官能团接枝合成了钴/锰双印迹半胱氨酸-壳聚糖树脂(CysCo/Mn-CCTS)。采用傅里叶红外光谱、扫描电镜对其结构进行了表征,并进行了干扰离子存在下低浓度Co2+和Mn2+静态、动态以及竞争吸附实验。静态实验结果表明,双印迹半胱氨酸-壳聚糖树脂较非印迹树脂的吸附性能有较大提高;干扰离子存在下,树脂对Co2+、Mn2+二元混合溶液中Co2+的吸附性能优于Mn2+,且对Co2+的吸附容量超过Mn2+的16倍。溶液的pH值、温度、吸附时间、干扰离子以及金属离子初始浓度均对树脂的吸附性能有较大影响,树脂对Co2+、Mn2+的吸附过程符合Lagergren准二级动力学和Langmuir模型。动态吸附实验表明,树脂对Co2+、Mn2+的吸附符合Thomas模型,对二者的穿透体积分别为308BV与506BV。

The Co^2＋/M^2＋ imprinted adsorbent grafted by cysteine （Cys-Co/Mn-CCTS） was synthesized via the combination of amino groups of cysteine with imprinted crosslinked chitosan （Co/Mn-CCTS） by combining sol-gel method with reverse phase suspension method involving both manganese nitrate and cobalt nitrate as imprint mole- cules. Their structures were analyzed utilizing the techniques of FTIR and SEM. The static and dynamic adsorption and competitive adsorption experiments for Co^2＋ and M^2＋ with low concentration were conducted, in presence of other ions. Static adsorp- tion experiments indicate that the performance of Cys-Co/Mn-CCTS is improved and the adsorption of Co^2＋ compared favorably with that of Mn~＋ in binary solutions, which are16 times more than that of M^2＋ in presence o{ other cations. The initial pH, tempera- ture, contact time, presence of other cations and initial Co^2＋ and M^2＋ concentrations have great effects on the adsorption performance. The adsorption data fit to Lagergren pseudo-second-order kinetics model and Dynamic adsorption data follow Thomas adsorbent for Co^2＋ and M^2＋ are 308 BV Langmuir model for both Co^2＋ and M^2＋. model and the breakthrough volumes of the and 506 BV, respectively.