硅球/亚铁氰化铜钾复合物固定床选择性去除污染水体中的Cs+及其影响因素

    Selective Removal of Cs+ From Contaminated Water Using Silicon Bead/Potassium Copper Ferrocyanide Composites in Fixed-Bed Column

    • 摘要: 采用柱上淋洗方式,在硅球(SiO2)填料上原位负载亚铁氰化铜钾(Cu-PBA),制得SiO2/Cu-PBA复合材料固定床吸附柱。采用扫描电镜-能谱(SEM-EDS)、红外光谱(FTIR)、粉末X射线衍射(XRD)和N2吸附等温测试等手段对材料进行表征,证实了Cu-PBA的成功负载。通过批式法吸附实验,明确了SiO2/Cu-PBA在模拟地下水中对Cs+的最大吸附容量约为4.0 mg/g,30 min内达吸附平衡。进而系统研究了该材料在固定床系统中对Cs+的吸附行为,包括柱床高、柱内径、进水流速和进水Cs+浓度的影响。在最优固定床实验条件下,对比了SiO2/Cu-PBA和阳离子交换树脂、在模拟地下水及模拟海水中保留Cs+及其他共存碱金属及碱土金属离子(K+、Na+、Ca2+和Mg2+)性能,结果表明,SiO2/Cu-PBA拥有优异的Cs+选择性和吸附性能,而树脂柱则在高盐分条件下失效。综上所述,SiO2/Cu-PBA复合物在环境污染水体中选择性去除Cs+方面具有很好的应用前景。

       

      Abstract: By using a column elution method, potassium copper ferrocyanide(Cu-PBA) was in situ loaded on silicon bead(SiO2) column packing, thereby yielding a SiO2/Cu-PBA fixed bed column. The characterizations of SiO2/Cu-PBA by SEM-EDS, FTIR, XRD and N2 adsorption-desorption isotherm techniques confirms the successful loading of Cu-PBA on SiO2. In batch experiments, it is found that the maximum adsorption capacity of SiO2/Cu-PBA for Cs+ is around 4.0 mg/g, and it needs 30 min to reach equilibrium adsorption. Then, the adsorpion behavior of Cs+ by the SiO2/Cu-PBA fixed bed was systematically studied, including the impacts of various operating parameters such as bed depth, bed diameter, flow rate, and influent Cs+ concentration. In the optimized fixed bed system, the adsorption behaviors of Cs+ and coexisting metal ions(K+, Na+, Ca2+, and Mg2+) by SiO2/Cu-PBA and cation-exchanged resin were compared in both simulated groundwater and seawater. The efficient and highly selective removal of Cs+ by SiO2/Cu-PBA is addressed as well as the inefficiency of cation-exchanged resin in simulated seawater. Therefore, the SiO2/Cu-PBA composite will have great application prospects in the continuous removal of Cs+ from various Cs+-contaminated environmental water media.

       

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