ABSTRACT

This study undertook the testing of Cu²⁺ and Ni²⁺ adsorption using synthesized oxalic acid-crosslinked chitosan (CTS)-modified montmorillonite (MMT), as well as a kinetic analysis and equilibrium analysis. We believe that our study makes a significant contribution to the literature because we showed that the interlayer distance of untreated MMT was increased from 1.23 to 2.05–2.21 nm, and thus verified the intercalation of CTS into the MMT interlayer. The maximum adsorption of Cu²⁺, as calculated using the Langmuir equation, was significantly higher for oxalic acid-crosslinked CTS-modified MMT, relative to untreated MMT or the non-crosslinked CTS-modified-MMT. The oxalic acid-crosslinked CTS-modified MMT could also take up more Cu²⁺ than Ni²⁺ from a solution containing a mixture of Cu²⁺-Ni²⁺. The selective adsorption of oxalic acid-crosslinked CTS-modified-MMT (i.e. Ni²⁺ < Cu²⁺) is governed by the selective adsorption of CTS and the oxalic acid. This reveals the effect of the complex formation with CTS and oxalic acid.

摘要

这项研究使用合成的草酸交联的壳聚糖（CTS）改性的蒙脱土（MMT）进行了Cu ²⁺和Ni ²⁺吸附的测试，以及动力学分析和平衡分析。我们认为我们的研究对文献做出了重大贡献，因为我们表明未经处理的MMT的层间距离从1.23 nm增加到2.05–2.21 nm，从而证明了CTS插入MMT层间。使用草酸交联的CTS修饰的MMT，相对于未处理的MMT或未交联的CTS修饰的MMT，使用Langmuir方程计算得出的Cu ²⁺的最大吸附量明显更高。草酸交联的CTS修饰的MMT也可以吸收更多的Cu ²⁺从含有Cu ²⁺ -Ni ²⁺的混合物中获得的Ni ^2+的含量要高于Ni ²⁺。草酸交联的CTS-改性-MMT（即Ni ²⁺ <Cu ²⁺）的选择性吸附受CTS和草酸的选择性吸附控制。这揭示了与CTS和草酸形成复合物的作用。