高氨基密度纤维素基固态胺吸附剂的制备及其性能研究

Preparation and Properties of High Amino Density Cellulose-based Solid Amine Adsorbent

以微晶纤维素(MCC)为基体,分别以3种结构不同的胺(小分子四乙烯五胺(TEPA)、支化聚乙烯亚胺(BPEI)、端氨基超支化聚胺(HBP-NH2))为功能试剂,采用环氧氯丙烷(ECH)"一步快速交联"的方法,制备了3种结构不同的高氨基密度纤维素基固态胺吸附剂,表征了3种吸附剂的结构以及对Cr(VI)的吸附性能和吸附机理。结果表明,通过对胺的结构设计和优化,在材料中引入超支化结构,实现了对Cr(VI)的快速高效去除,高氨基密度不仅保障了高浓度Cr(VI)(100 mg/L)的高去除率(99%以上),更是实现了低浓度Cr(VI)(1 mg/L)的完全去除,吸附后水体中的Cr(VI)残留浓度达到我国GB 5749-2006 《生活饮用水卫生标准》中对Cr(VI)浓度的要求。3种吸附剂具有良好的再生性能,循环再生6次后,其对Cr(VI)的去除率仍然保持在98%以上。

Using microcrystalline cellulose(MCC)as matrix and three amines with different structures(tetraethylene pentamine(TEPA),polyethyleneimine(BPEI)and amino terminated hyperbranched polyamine(HBP-NH2))as functional reagents,three kinds of high amino density cellulose-based solid amine adsorbents with different structures were prepared by the method of "one-step rapid crosslinking" with epichlorohydrin(ECH).The structures of the three adsorbents were characterized,the adsorption properties and mechanism for Cr(VI)were invertigated.The results showed that the high amino density of adsorbents not only guaranteed the high removal rate(above 99%)of high concentration Cr(VI)(100 mg/L),but also achieved the complete removal of low concentration Cr(VI)(1 mg/L).The residual Cr(VI)concentration in water after removing Cr(VI)met the current national drinking water standard(GB 5749—2006).Through the structural design and optimization of amines,the adsorbent with hyperbranched structure could remove Cr(VI)quickly and efficiently.After six times of recycling,the removal rate of the adsorbent for Cr(VI)was still above 98%,which indicates that the adsorbents have good application prospects.