钴/锰印迹谷氨酸-壳聚糖对低浓度Mn2 和Co2 的选择性吸附

以硝酸锰和硝酸钴为印迹分子,采用反相悬浮和溶胶凝胶法结合制备了双印迹交联壳聚糖微球(Co/MnCCTS),并与谷氨酸的氨基接枝合成钴/锰双印迹谷氨酸-壳聚糖吸附剂(Glu-Co/Mn-CCTS)。采用傅里叶变换红外光谱、扫描电镜对其结构进行了表征,并进行了低质量浓度Co2+和Mn2+的静态吸附实验。结果表明,溶液的p H、温度和初始质量浓度、吸附时间、干扰离子对Glu-Co/Mn-CCTS的吸附性能均有较大影响,Glu-Co/Mn-CCTS对Co2+、Mn2+的吸附过程符合Lagergren准二级动力学以及Freundlich和Langmuir等温吸附模型;303 K下,当p H=4~7时,对Co2+和Mn2+的去除率均在98%以上;303 K下,当p H约为5.5时,对Co2+和Mn2+的去除率在吸附4 h后均在96%以上;干扰离子存在下,吸附剂对Co2+的选择吸附性能和抗干扰能力优于Mn2+。

Selective Adsorption of Mn2 and Co2 in Dilute Solution by Cobalt/Manganese Imprinted Glutamic Acid Grafted Chitosan

Glu-Co/Mn-CCTS was synthesized via the combination of amino group of glutamic acid 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 molecules. Their structures were analyzed utilizing the techniques of FTIR and SEM. The static adsorption experiments for Co2 and Mn2 with low concentration indicate that the initial pH, temperature and initial Co2 and Mn2 concentrations, contact time, presence of other cations have great effects on the adsorption performance. The adsorption datas fit to pseudo-second-order , Langmuir and Freundlich models for both Co2 and Mn2 . The removal rates of Co2 and Mn2 are all above 98% at pH values from 4 to7 at 303K, which reach 96% after 2 h at pH value of about 5.5. The adsorption performance of Co2 on Glu-Co/Mn-CCTS compared favorably with that of Mn2 in presence of other cations.