随着工业化的快速发展，废水污染问题日益严重。ZIF-8因其具有大比表面积和优异的化学稳定性被广泛研究用于废水处理领域。然而，ZIF-8的粉末性质导致其难以与水溶液分离，严重限制了它在废水处理中的实际应用。此外，用于废水处理领域的液-液萃取技术也存在水相与有机相分离困难的应用限制。水凝胶作为一种具有三维网络结构的聚合物，不仅可以用来作为负载固体颗粒的载体，还可以用作封装有机萃取剂的固体基质。由固体颗粒作为稳定剂的Pickering乳液具有环境友好和乳液稳定性好等优点。因此，为了解决废水处理中ZIF-8难以与水溶液分离和液-液萃取技术分离水相与有机相困难的问题。本论文将ZIF-8与水凝胶复合来制备复合水凝胶，并结合Pickering乳液，开发出了可以包裹有机萃取剂的Pickering乳液水凝胶。这些复合水凝胶材料为制备用于去除废水污染物的新型吸附剂提供了思路。

 本论文以水凝胶为基础来制备ZIF-8复合水凝胶材料。首先，将ZIF-8与Fe₃O₄复合制备Fe₃O₄@ZIF-8，采用自由基聚合法将其与水凝胶结合制备了具有磁性的水凝胶小球。随后，分别使用ZIF-8和Fe₃O₄@ZIF-8作为Pickering乳液稳定剂，采用Pickering乳液聚合法将有机萃取剂包裹在水凝胶基质中制备了Pickering乳液水凝胶。最后，对上述所制备的复合水凝胶进行吸附性能研究。具体研究如下：

（1）首先将ZIF-8与Fe₃O₄复合制备Fe₃O₄@ZIF-8，然后以聚丙烯酰胺/海藻酸钠（PAM/SA）水凝胶为载体，采用自由基聚合法制备了磁性PAM/SA/Fe₃O₄@ZIF-8水凝胶小球并将其用于水中染料刚果红（CR）的吸附。结果表明，磁性PAM/SA/Fe₃O₄@ZIF-8-8对CR的吸附能力是PAM/SA的2.26倍，对CR的最大吸附量为234.69 mg/g。CR在磁性PAM/SA/Fe₃O₄@ZIF-8-8上的吸附遵循伪二级动力学模型和Freundlich等温线模型。热力学研究表明吸附过程是吸热和自发的。磁性PAM/SA/Fe₃O₄@ZIF-8-8对CR的吸附机制主要是静电吸引，金属配位、氢键和π-π相互作用。磁性PAM/SA/Fe₃O₄@ZIF-8-8水凝胶小球可用磁铁易于与水溶液分离，对CR具有优异的选择吸附性能和良好的循环再生性能，具有去除废水中CR的潜力。

      （2）通过使用ZIF-8作为Pickering乳液稳定剂，然后采用Pickering乳液聚合法制备了包裹铜萃取剂N902的ZIF-8-PEHGs（以ZIF-8作为Pickering乳液稳定剂所制备的Pickering乳液水凝胶），并将其应用于水中铜离子（Cu(II)）的去除。实验结果表明N902被ZIF-8-PEHGs成功包裹。ZIF-8-PEHGs吸附Cu(II)的平衡时间为50 min，最佳吸附量为20.79 mg/g。ZIF-8-PEHGs对Cu(II)的去除主要是靠包裹在ZIF-8-PEHGs内的N902与Cu(II)发生络合反应来实现的。ZIF-8-PEHGs对Cu(II)的吸附遵循伪二级动力学模型和Langmuir等温线模型。在经过5次吸附-解吸循环后，ZIF-8-PEHGs对Cu(II)的吸附量仍然保持在初始吸附量的80%。本项工作为制备用于去除Cu(II)废水的新型Pickering乳液水凝胶材料提供了思路。

（3）通过使用Fe₃O₄@ZIF-8作为Pickering乳液稳定剂，采用Pickering乳液聚合法制备了包裹铜萃取剂N902的磁性Fe₃O₄@ZIF-8-PEHGs（以Fe₃O₄@ZIF-8作为Pickering乳液稳定剂所制备的Pickering乳液水凝胶），并将其应用于水中Cu(II)的去除。实验结果发现，磁性Fe₃O₄@ZIF-8-PEHGs对Cu(II)的吸附量是HGs的4.25倍，最佳吸附量为18.64 mg/g。Cu(Ⅱ)在磁性Fe₃O₄@ZIF-8-PEHGs上的吸附符合伪二级动力学模型，并且实验数据与Langmuir等温线模型拟合程度更好。Langmuir等温线模型参数表明磁性Fe₃O₄@ZIF-8-PEHGs对Cu(Ⅱ)的吸附是容易进行的。磁性Fe₃O₄@ZIF-8-PEHGs可以使用磁铁易于从水中回收，为制备去除Cu(Ⅱ)废水的磁性Pickering乳液水凝胶材料提供了参考。

With the rapid development of industrialisation, the problem of wastewater pollution is increasingly serious. ZIF-8 has been widely studied for wastewater treatment due to its large specific surface area and excellent chemical stability. However, the powder nature of ZIF-8 makes it difficult to separate from aqueous solutions, which severely limits its practical application in wastewater treatment. In addition, the liquid-liquid extraction technology used in wastewater treatment also suffers from the limitation of difficulty in separating the aqueous phase from the organic phase. Hydrogel, as a polymer with a three-dimensional network structure, can be used not only as a carrier for loading solid particles but also as a solid matrix for encapsulating organic extractants. Pickering emulsions with solid particles as stabilisers have the advantages of being environmentally friendly and having good emulsion stability. Therefore, to solve the problems of wastewater treatment in which ZIF-8 is difficult to separate from aqueous solution and the liquid-liquid extraction technique is difficult to separate the aqueous phase from the organic phase. In this thesis, ZIF-8 was compounded with hydrogel to prepare composite hydrogels and combined with Pickering emulsion to develop Pickering emulsion hydrogels that can encapsulate organic extractants. These composite hydrogel materials provide ideas for the preparation of novel adsorbents for the removal of wastewater pollutants. 

In this thesis, hydrogel was used as a base to prepare ZIF-8 composite hydrogel materials. Firstly, Fe₃O₄@ZIF-8 was prepared by compounding ZIF-8 with Fe₃O₄, and then it was combined with hydrogel by free radical polymerization to prepare hydrogel beads with magnetic properties. Subsequently, the Pickering emulsions were stabilized using ZIF-8 and Fe₃O₄@ZIF-8, respectively, and Pickering emulsion hydrogels were prepared by encapsulating the organic extractant in a hydrogel matrix using Pickering emulsion polymerisation. Finally, the adsorption performance of the above prepared composite hydrogels was studied. The specific studies are as follows:

(1) Firstly, Fe₃O₄@ZIF-8 was prepared by compounding ZIF-8 with Fe₃O₄, and then magnetic PAM/SA/Fe₃O₄@ZIF-8 hydrogel beads were prepared by free radical polymerisation method using polyacrylamide/sodium alginate (PAM/SA) hydrogel as a carrier for adsorption of the dye Congo red (CR) in water. The results showed that the adsorption capacity of magnetic PAM/SA/Fe₃O₄@ZIF-8 for CR was 2.26 times more than that of PAM/SA, and the maximum adsorption of CR was 234.69 mg/g. The adsorption of CR on magnetic PAM/SA/Fe₃O₄@ZIF-8-8 followed the Pseudo-second-order kinetic model and the Freundlich isotherm model. Thermodynamic studies showed that the adsorption process was heat-absorbing and spontaneous. The adsorption mechanism of magnetic PAM/SA/Fe₃O₄@ZIF-8-8 on CR was mainly based on electrostatic attraction, metal coordination, hydrogen bonding, and π-π interaction. Magnetic PAM/SA/Fe₃O₄@ZIF-8-8 hydrogel beads can be easily separated with aqueous solution by magnets, and have excellent selective adsorption performance and good cyclic regeneration performance for CR, which has the potential to remove CR from wastewater.

(2) ZIF-8-PEHGs (Pickering emulsion hydrogels prepared with ZIF-8 as Pickering emulsion stabilizer) encapsulating copper extractant N902 were prepared by Pickering emulsion polymerization using ZIF-8 as a Pickering emulsion stabiliser and applied to the removal of copper ions (Cu(II)) from water. The experimental results showed that N902 was successfully encapsulated by ZIF-8-PEHGs. The equilibrium time for the adsorption of Cu(II) by ZIF-8-PEHGs was 50 min, and the optimum adsorption amount was 20.79 mg/g. The removal of Cu(II) by ZIF-8-PEHGs was mainly achieved by the complexation reaction between N902 encapsulated in ZIF-8-PEHGs and Cu(II). The adsorption of Cu(II) by ZIF-8-PEHGs followed the Pseudo-second-order kinetic model and the Langmuir isotherm model. After five adsorption-desorption cycles, the adsorption of Cu(II) by ZIF-8-PEHGs remained at 80% of the initial adsorption amount. This work provides ideas for the preparation of new Pickering emulsion hydrogel materials for Cu(II) wastewater removal.

(3) Magnetic Fe₃O₄@ZIF-8-PEHGs (Pickering emulsion hydrogels prepared with Fe₃O₄@ZIF-8 as Pickering emulsion stabilizer) encapsulating copper extractant N902 were prepared by Pickering emulsion polymerisation using Fe₃O₄@ZIF-8 as a Pickering emulsion stabiliser and applied for Cu(II) removal from water. It was found that the adsorption amount of magnetic Fe₃O₄@ZIF-8-PEHGs for Cu(II) was 4.25 times more than that of HGs, and the optimum adsorption amount was 18.64 mg/g. The adsorption of Cu(II) on magnetic Fe₃O₄@ZIF-8-PEHGs was consistent with the Pseudo-second-order kinetic model, and the experimental data are better fitted to the Langmuir isotherm model. Langmuir isotherm model parameters showed that the adsorption of Cu(II) by magnetic Fe₃O₄@ZIF-8-PEHGs was easily performed. Magnetic Fe₃O₄@ZIF-8-PEHGs can be easily recovered from water using magnets, providing a reference for the preparation of magnetic Pickering emulsion hydrogel materials for Cu(II) wastewater removal.

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