为了实现矿井水中重金属污染治理和资源化利用，本文采用改进Hummers法制备的氧化石墨烯（GO），以其为吸附剂，将铅锌矿井水中的Pb²⁺、Zn²⁺进行吸附分离，实现矿井水中重金属离子的去除，然后以吸附重金属离子的GO为原料，分别以对苯二甲酸（BDC）和2-甲基咪唑（DMZ）为有机配体，采用水热法和室温晶化法，在GO表面原位合成Pb/Zn(BDC)MOF@GO和Pb/Zn(DMZ)MOF@GO双金属MOF@GO复合材料，并与单/双金属MOF及单金属MOF@GO复合材料进行对比。利用SEM、XRD、FTIR、BET等表征方法对所合成的系列MOF及复合材料的物理化学结构进行系统分析。探讨了复合材料合成过程中重金属离子吸附量、不同有机配体和合成方法等因素对材料性能和结构的影响。采用静态吸附实验研究了所合成的双金属复合材料MOF@GO对模拟废水中重金属离子Pb²⁺、Zn²⁺、典型有机污染物亚甲基蓝（MB）染料和抗生素诺氟沙星（NOR）的吸附性能和机理。

基于以上研究，分析并提出了水中Pb²⁺、Zn²⁺的吸附分离-原位合成MOF@GO的机理和重金属离子的绿色循环利用机制。本文主要研究成果如下：

（1）采用改进Hummers法制备氧化石墨烯吸附材料，并对其进行了SEM、FTIR、BET、XRD表征分析，研究其对水溶液中Pb²⁺、Zn²⁺以及混合溶液的吸附分离性能。所制备GO的比表面积为10.73m²/g，SEM分析表明，GO层状结构清晰，FTIR分析表明，GO含有-COOH、-C=O、-OH等含氧官能团。GO对单一Pb²⁺、Zn²⁺的平衡吸附量分别为99.4、85.12mg/g，对混合溶液中的Pb²⁺、Zn²⁺的平衡吸附量分别为95.36、72.68mg/g，说明两种离子在GO吸附过程中存在竞争，GO对Pb²⁺、Zn²⁺的吸附动力学都满足二级动力学模型，所计算得出的平衡吸附量q_e.c分别为101、85.17mg/g，与实际值q_e接近。GO对Pb²⁺、Zn²⁺的吸附等温线均满足Freundlich模型。吸附热力学参数ΔG＜0，ΔH＜0，表明GO对Pb²⁺、Zn²⁺的吸附过程是自发放热反应。水溶液中共存盐分的浓度对GO的吸附性能影响较大。Weber-Morris内扩散方程揭示，吸附过程由颗粒内扩散控制。

（2）分别以Pb²⁺、Zn²⁺溶液及其混合溶液、吸附重金属离子的GO为原料，以BDC为有机配体，采用水热法原位合成了Pb(BDC)MOF、Zn(BDC)MOF单金属MOF和Pb/Zn (BDC)MOF双金属MOF及相对应的Pb(BDC)MOF@GO、Zn(BDC)MOF@GO、Pb/Zn (BDC)MOF@GO系列MOF@GO复合材料，对其结构进行表征和对比分析。SEM分析表明单双金属MOF的外形为多面体结构。随着GO对重金属离子吸附容量的增加，MOF晶体与GO结合形成了多面体掺杂的片状复合结构。XRD分析表明单金属MOF和双金属MOF材料的特征峰在MOF@GO复合材料相同位置均有出现，证明MOF@GO复合材料合成成功。FTIR表征分析也得出相同结论。BET比表面积和孔道结构分析表明，合成的Pb(BDC)MOF@GO、Zn(BDC)MOF@GO和Pb/Zn(BDC)MOF@GO的BET比表面积分别为296、408和460m²/g，双金属MOF@GO的BET比表面积明显高于单金属MOF@GO，孔径分布曲线表明合成的复合材料属于微-介孔复合结构。

（3）分别以Pb²⁺、Zn²⁺溶液及其混合溶液、吸附重金属离子的GO为原料，以DMZ为有机配体，采用室温晶化法合成了Pb(DMZ)MOF、Zn(DMZ)MOF单金属MOF和Pb/Zn (DMZ)MOF双金属MOF及Pb(DMZ)MOF@GO、Zn(DMZ)MOF@GO、Pb/Zn(DMZ) MOF@GO系列复合材料，对其结构进行表征和对比分析。SEM分析表明单/双金属MOF的微观形貌均呈现出多面体颗粒状结构，由于复合材料合成过程中MOF晶体与GO相互作用，在GO表面的MOF晶体呈现出嵌入式多面立体结构。XRD和FTIR表征分析表明Pb(DMZ)MOF@GO、Zn(DMZ)MOF@GO和Pb/Zn(DMZ)MOF@GO系列复合材料原位合成成功。Pb/Zn(DMZ)MOF@GO复合材料的BET比表面积可达518m²/g，要高于Pb(DMZ)MOF@GO的397m²/g和Zn(DMZ)MOF@GO的456m²/g，说明双金属MOF与GO结合提高了复合材料的BET比表面积，有利于暴露更多的活性吸附位点，增强吸附材料对吸附质的捕获。

（4）Pb(BDC)MOF@GO、Zn(BDC)MOF@GO、Pb/Zn(BDC)MOF@GO、Pb(DMZ) MOF@GO、Zn(DMZ)MOF@GO和Pb/Zn(DMZ)MOF@GO对模拟废水溶液中单一Pb²⁺、Zn²⁺的吸附性能研究表明：六种复合材料对Pb²⁺、Zn²⁺的吸附动力学和吸附等温线均更符合二级动力学模型及Langmuir吸附等温线模型。Pb/Zn(DMZ)MOF@GO、Pb/Zn(BDC) MOF@GO对Pb²⁺、Zn²⁺的平衡吸附量分别为130.4、121.2mg/g和86.93、78.95mg/g，高于其他四种复合材料。FTIR分析表明，Pb/Zn(BDC)MOF@GO和Pb/Zn(DMZ) MOF@GO对Zn²⁺的吸附机理主要为离子交换和配位反应。

（5）SEM、XRD、FTIR对比分析表明，以陕西凤县某铅锌矿实际矿井水为原料，通过吸附分离-原位合成可成功制备Pb/Zn(BDC)MOF@GO-W和Pb/Zn(DMZ)MOF@GO -W复合材料，其比表面积分别为437.75m²/g和468.11m²/g，都具有微孔、介孔孔隙结构。Pb/Zn(DMZ)MOF@GO-W和Pb/Zn(BDC)MOF@GO-W对Pb²⁺、Zn²⁺、NOR、MB的平衡吸附量分别为86.72、64.20、96.49、89.62mg/g和74.08、62.68、94.33、71.69mg/g。两种复合材料对Pb²⁺、Zn²⁺、NOR、MB的吸附动力学和吸附等温线均更符合二级动力学模型和Langmuir吸附等温线模型。吸附热力学结果表明两种复合材料对Pb²⁺、Zn²⁺、NOR、MB的吸附过程是自发放热过程。通过对NOR、Zn²⁺的吸附、再生、循环利用实验，循环利用6次后，Pb/Zn(DMZ) MOF@GO-W和Pb/Zn(BDC)MOF@GO-W对NOR、Zn²⁺的平衡吸附量仍分别有80.4、60.2mg/g和76.5、56.8mg/g，具有较好的循环利用性。FTIR分析表明，两种材料对Zn²⁺的吸附机理为离子交换、配位反应。对NOR、MB为氢键作用和π共轭。

In order to realize the treatment and resource utilization of heavy metal pollution in mine water, graphene oxide (GO) prepared by improved Hummers method was used as adsorbent to adsorb and separate Pb²⁺ and Zn²⁺ in simulated lead-zinc mine water, so as to realize the removal of heavy metal ions in mine water. Then, GO adsorbed heavy metal ions was used as raw material, terephthalic acid (BDC) and 2-methylimidazole (DMZ) were used as organic ligands respectively, and hydrothermal method and room temperature crystallization method were used. Pb/Zn(BDC)MOF@GO and Pb/Zn (DMZ)MOF@GO bimetallic MOF@GO composites were synthesized in situ on the surface of GO, and compared with single / bimetallic MOF and single metal MOF@GO composites. The physical and chemical structures of the synthesized MOF and composites were systematically analyzed by SEM, XRD, FTIR and BET. The effects of heavy metal ion adsorption, different organic ligands and synthesis methods on the properties and structure of the composites were discussed. The adsorption performance and mechanism of the synthesized bimetallic composite MOF@GO for heavy metal ions Pb²⁺, Zn²⁺, typical organic pollutant methylene blue (MB) dye and antibiotic norfloxacin (NOR) in simulated wastewater were studied by static adsorption experiments.

Based on the above research, the mechanism of adsorption and separation of Pb²⁺ and Zn²⁺ in water-in-situ synthesis of MOF @ GO and the green recycling mechanism of heavy metal ions were analyzed and proposed. The main research results are as follows :

 (1) Graphene oxide adsorption materials were prepared by modified Hummers method, and characterized by SEM, FTIR, BET and XRD. The adsorption and separation properties of Pb²⁺, Zn²⁺ and mixed solution were studied. The specific surface area of GO was 10.73 m²/g. SEM analysis showed that the layered structure of GO was clear. FTIR analysis showed that GO contained oxygen-containing functional groups such as-COOH, -C=O and-OH. The equilibrium adsorption capacities of GO for single Pb²⁺ and Zn²⁺ were 99.4 mg/g and 85.12 mg/g, respectively. The equilibrium adsorption capacities of GO for Pb²⁺ and Zn²⁺ in mixed solution were 95.36 mg/g and 72.68 mg/g, respectively, indicating that there was competition between the two ions in the adsorption process of GO. The adsorption kinetics of Pb²⁺ and Zn²⁺ by GO satisfied the second-order kinetic model. The calculated equilibrium adsorption capacities q_e.c were 101 mg/g and 85.17 mg/g, respectively, which were close to the actual value qe. The adsorption isotherms of Pb²⁺ and Zn²⁺ on GO meet the Freundlich model. The adsorption thermodynamic parameters ΔG < 0 and ΔH < 0, indicating that the adsorption process of GO on Pb²⁺ and Zn²⁺ is a spontaneous exothermic reaction. The concentration of coexisting salts in aqueous solution has a great influence on the adsorption performance of GO. The Weber-Morris intraparticle diffusion equation revealed that the adsorption process was controlled by intraparticle diffusion.

(2) Pb (BDC)MOF, Zn (BDC)MOF single metal MOF, Pb/Zn(BDC)MOF bimetallic MOF and corresponding Pb(BDC)MOF@GO, Zn(BDC)MOF@GO, Pb/Zn(BDC)MOF@GO series MOF@GO composites were synthesized in situ by hydrothermal method using Pb²⁺, Zn²⁺ solution and their mixed solution, GO adsorbing heavy metal ions as raw materials, and BDC as organic ligand. SEM analysis shows that the shape of single and double metal MOF is polyhedron structure. With the increase of the adsorption capacity of GO for heavy metal ions, MOF crystals combined with GO to form a polyhedral doped sheet composite structure. XRD analysis showed that the characteristic peaks of single metal MOF and bimetallic MOF materials appeared at the same position of MOF@GO composites, which proved that MOF@GO composites were successfully synthesized. FTIR characterization analysis also reached the same conclusion. BET specific surface area and pore structure analysis showed that the BET specific surface areas of Pb(BDC)MOF@GO, Zn(BDC)MOF@GO and Pb/Zn(BDC) MOF@GO were 296, 408 and 460 m²/g, respectively. The BET specific surface area of bimetallic MOF@GO was significantly higher than that of single metal MOF@GO. The pore size distribution curve showed that the synthesized composite material belonged to the micro-mesoporous composite structure.

(3) Pb(DMZ)MOF, Zn(DMZ)MOF single metal MOF, Pb/Zn(DMZ)MOF bimetallic MOF and Pb(DMZ)MOF@GO, Zn(DMZ)MOF@GO, Pb/Zn(DMZ)MOF@GO series composites were synthesized by room temperature crystallization method using Pb²⁺, Zn²⁺ solution and their mixed solution, GO adsorbing heavy metal ions as raw materials, and DMZ as organic ligand. The structures were characterized and compared. SEM analysis showed that the microstructure of single / bimetallic MOF showed a polyhedral granular structure. Due to the interaction between MOF crystals and GO during the synthesis of composite materials, the MOF crystals on the surface of GO showed an embedded polyhedral structure. XRD and FTIR characterization analysis showed that Pb(DMZ)MOF@GO, Zn(DMZ)MOF@GO and Pb/Zn (DMZ)MOF@GO series composites were successfully synthesized in situ. The BET specific surface area of Pb/Zn(DMZ)MOF@GO composites can reach 518m²/g, which is higher than that of Pb(DMZ)MOF@GO ( 397m²/g ) and Zn(DMZ)MOF@GO (456m²/g ), indicating that the combination of bimetallic MOF and GO improves the BET specific surface area of the composites, which is conducive to exposing more active adsorption sites and enhancing the capture of adsorbates by the adsorbent.

(4) The adsorption properties of Pb(BDC)MOF@GO, Zn(BDC)MOF@GO, Pb/Zn(BDC) MOF@GO, Pb(DMZ)MOF@GO, Zn(DMZ)MOF@GO and Pb/Zn(DMZ)MOF@GO on single Pb²⁺ and Zn²⁺ in simulated wastewater were studied. The results showed that the adsorption kinetics and adsorption isotherms of Pb²⁺ and Zn²⁺ by the six materials were more consistent with the second-order kinetic model and Langmuir adsorption isotherm model. The equilibrium adsorption capacities of Pb/Zn(DMZ)MOF@GO and Pb/Zn(BDC)MOF@GO for Pb²⁺ and Zn²⁺ were 130.4, 121.2 mg/g and 86.93, 78.95 mg/g, respectively, which were higher than those of the other four composites. FTIR analysis showed that the adsorption mechanism of Pb/Zn(BDC)MOF@GO and Pb/Zn(DMZ)MOF@GO for Zn²⁺ was mainly ion exchange and coordination reaction.

(5) The comparative analysis of SEM, XRD and FTIR shows that Pb/Zn(BDC)MOF@ GO-W and Pb/Zn(DMZ)MOF@GO-W composites can be successfully prepared by adsorption separation-in-situ synthesis using actual mine water from a lead-zinc mine in Fengxian County, Shaanxi Province as raw material. The specific surface areas of Pb/Zn(BDC)MOF@GO-W and Pb/Zn(DMZ)MOF@GO-W composites are 437.75 m²/g and 468.11 m²/g, respectively, and both have microporous and mesoporous pore structures. The equilibriumadsorptioncapacitiesofPb/Zn(DMZ)MOF@GO-W and Pb/Zn(BDC)MOF@GO-W for Pb²⁺, Zn²⁺, NOR and MB were 86.72, 64.20, 96.49, 89.62 mg/g and 74.08, 62.68, 94.33, 71.69 mg/g, respectively. The adsorption kinetics and adsorption isotherms of Pb²⁺, Zn²⁺, NOR and MB on the two composites are more in line with the second-order kinetic model and the Langmuir adsorption isotherm model. The adsorption thermodynamics results show that the adsorption process of Pb²⁺, Zn²⁺, NOR and MB on the two composites is a spontaneous exothermic process. Through the adsorption, regeneration and recycling experiments of NOR and Zn²⁺, the equilibrium adsorption capacities of Pb/Zn(DMZ)MOF@GO-W and Pb/Zn(BDC)MOF@GO-W for NOR and Zn²⁺ were still 80.4, 60.2 mg/g and 76.5, 56.8 mg/g after 6 times of recycling, respectively. FTIR analysis showed that the adsorption mechanism of Zn²⁺ on the two materials was ion exchange and coordination reaction. For NOR and MB, there are hydrogen bonding and π conjugation.