Development of new inorganic-biomass adsorbents using sol-gel method and establishment of innovative separation process for critical metals

研究了壳聚糖对伯胺的吸附和木质素对酚基和羟基的吸附，阐明了它们的化学结构与对关键金属的选择性之间的关系。我们还发现，离子印迹法制备的吸附剂不仅能识别目标金属离子的离子大小，而且能识别其复杂的结构。通过溶胶-凝胶法将壳聚糖衍生物与二氧化硅（TEOS）交联，制备了具有多孔孔的二氧化硅/壳聚糖衍生物杂化吸附剂。杂化吸附剂对贵金属具有较高的选择性，而木质素上的杂化吸附剂对铅、镉、锌等贱金属具有选择性吸附。二氧化硅/壳聚糖衍生物的空速是常规柱法空速的50-500倍。采用浸渍法制备了壳聚糖包覆滤料，并利用该滤料对工业废渣中的铟和镓进行了选择性回收。

New adsorbents using chitosan with the primary amine and lignin with phenolic and hydroxyl groups were developed to elucidate the relationship between their chemical structures and selectivity for critical metals. We also found that the adsorbents prepared by the ion-imprinting method were able to recognize not the ion-size of target metal ion but its complex structure. The hybrid adsorbents of silica/chitosan derivatives with through-pores also were obtained by cross-linking the chitosan derivatives with silica (TEOS) using the sol-gel method. The hybrid adsorbents exhibited the high selectivity for precious metals while those on lignin exhibited the selective adsorption for base metals such as Pb, Cd and Zn. Silica/chitosan derivatives achieved the space velocity (SV) of 50-500 folds over the conventional SV in column method. Chitosan-coated filter was also prepared by a dipping method, and selective recovery of In over Ga from industrial wastes was established using this filter.