新型簇基微孔配位聚合物的合成及吸附处理酸性矿山废水

According to the characteristics of the acid mine drainage in Guangxi, this project intends to adopt larger pKa values of three hydroxymethyl aminomethane Schiff base and reduction Schiff base for organic ligands, transition metal compound as precursor clusters. Cluster microporous coordination polymers will be constructed through the reaction of the linear alkaline organic ligand as a bridge, and higher valence state metal ions such as trivalent aluminium, tetravalent zirconium. It will be characterized by x-ray single-crystal diffraction, IR, UV, MS, NMR and so on. The stability of the cluster microporous coordination polymers will be determined by TG and PXRD. To establish the theoretical model of adsorption mechanism, cluster microporous coordination polymers will be used for treatment of simulated wastewater containing arsenic and cadmium. Moreover, the polymers will be analyzed by infrared spectroscopy, X-ray photoelectron spectroscopy on adsorption of before, during and after. The channel structure, size and molecular wall weak interaction will determine the adsorption effection on waste water of arsenic and cadmium. Through adsorption treatment effect to improve the structure design of the polymers to get good performance of the novel cluster microporous coordination polymers as adsorption materials. The novel adsorption materials will be used for treatment of acid mine drainage. Furthermore, the optimum process conditions will also be studied. This project will provide depth treatment on acid mine drainage with new materials and new technologies. It will have important practical significance to solve the problems of environmental pollution by acid mine drainage in guangxi.

根据广西酸性矿山废水的特点，本项目拟采用pKa值大的三羟甲基氨基甲烷席夫碱及还原席夫碱为有机配体，过渡金属簇合物作为前驱体，以线性碱性有机桥连配体为桥，与高价金属离子如三价铝、四价锆等反应，构筑新型簇基微孔配位聚合物吸附剂。通过X-射线单晶衍射仪和波谱学来表征聚合物的结构，用TG、变温粉末衍射仪表征聚合物的稳定性。将簇基微孔配位聚合物用来吸附处理含砷、镉的模拟废水，建立吸附机理的理论模型。用红外光谱、X 射线光电子能谱等对吸附前后的聚合物进行分析，进一步研究其孔道结构、尺寸、孔道分子壁弱作用等对废水中砷、镉吸附作用的影响。通过吸附处理效果来改进该聚合物的结构设计以得到性能优良的新型吸附材料。将该材料用于处理实际酸性矿山废水，研究其最佳处理工艺条件。本项目将为深度处理酸性矿山废水提供新材料、新技术，对解决广西酸性矿山废水污染环境的问题具有重要的现实意义。

为了保护矿山生态环境，根据广西酸性矿山废水的特点，研究合成新型吸附材料的新方法。通过溶剂热法、溶剂挥发法等，采用三羟甲基氨基甲烷席夫碱及还原席夫碱为有机配体，过渡金属簇合物作为前驱体，以线性碱性有机桥连配体为桥，合成6种新型簇基微孔配位聚合物，包括单核（{[Pb(HL)]·(4,4′-bpy)(H2O)}n、MOF-74-Zn）、双核（K-La-MOF、GUT-4）、四核（Co- MOFs）、八核（Zn-MOFs）等不同核数的簇合物。将这6种聚合物用来吸附处理含Cd(Ⅱ)和As(Ⅴ)的模拟废水，实现了废水达标排放。对吸附前后的材料进行XRD分析、XPS分析、SEM图像和EDS能谱分析、FT-IR分析，以研究其结构与处理效果的关系，建立吸附机理理论模型，包括吸附等温线模型、吸附动力学模型和Box-Behnken响应曲面优化模型等。进一步研究其孔道结构、尺寸、孔道分子壁弱作用等对废水中Cd(Ⅱ)和As(Ⅴ)吸附作用的影响，从而改进其结构设计以得到性能优良的新型吸附材料。将其中的新型吸附材料GUT-4和Zn-MOF-74用于处理含Cd(Ⅱ)和As(Ⅴ)的酸性矿山废水，得到其最佳处理工艺条件，排放废水均达到《污水综合排放标准》GB 8978-1996中的第一类污染物最高允许排放浓度标准，即总砷≤0.5 mg/L，总镉≤0.1 mg/L。这些新材料和新技术对解决广西酸性矿山废水污染环境的问题具有重要的现实意义。