石墨烯水凝胶对浮选废水中残余药剂和重金属离子的协同去除机理研究

To solve the problem that the organic chemicals and heavy metal ions in flotation wastewater cannot be effectively removed at the same time, graphene hydrogel will be used as an adsorbent to carry out an integrated treatment on the flotation wastewater. Meanwhile, the synergistic adsorption efficiency and mechanism of the graphitization and oxidation regions of graphene hydrogel on organic chemicals and heavy metal ions will be studied. Unpurified high-grade natural cryptocrystalline graphite will be used to prepare graphene hydrogel to reduce the cost of this new porous adsorbent. Through the characterization of the porous structure of graphene hydrogel and the study on its graphitization structure and oxidation functional groups, the structural basis of simultaneous treatment of organic agents and heavy metal ions by graphene hydrogel was revealed. On this basis, the influence of the synergistic effect during the adsorption process on the adsorption capacity, the rate and the kinetics of each pollutant component was studied, this kind of synergistic effect may exist not only between the pollutants but also between the graphitized area and the oxidized area of the hydrogel. Through the establishment of diffusion and adsorption models, the synergistic mechanism was analyzed to establish the optimal condition strategy for the comprehensive treatment of multicomponent pollutants by graphene hydrogel. The research results of this project will have important scientific significance for further understanding and developing the basic theory and technical application of the adsorption and removal of the pollution components in flotation wastewater by graphene hydrogel.

针对浮选废水中有机药剂和重金属离子难以被同时有效除去的难题，将石墨烯水凝胶作为吸附剂来对浮选废水进行综合处理，研究其石墨化区域和氧化区域对有机药剂和重金属离子的协同吸附效能和机制。同时未经提纯的高品位天然隐晶质石墨被用于制备石墨烯水凝胶以降低这种新型多孔吸附剂的成本。通过对石墨烯水凝胶多孔结构的表征以及其石墨化结构和氧化官能团的研究，揭示石墨烯水凝胶同时处理有机药剂和重金属离子的结构基础。在此基础上，研究吸附过程中污染物之间以及水凝胶石墨化区域和氧化区域之间的协同作用对各污染组分吸附容量、速率、动力学的影响。通过扩散和吸附模型的建立分析协同作用的机制，建立石墨烯水凝胶综合处理多组分污染物的最优条件策略。该项目的研究成果将对深入认识和发展石墨烯水凝胶吸附去除浮选废水中污染组分的基础理论和技术应用具有重要的科学意义。

选矿废水成分复杂，有害成分种类较多而且浓度较低，找到一种能同时处理多种有害物质的吸附材料至关重要。石墨烯水凝胶是以石墨烯为主体的具有高比表面积的三维多孔新型碳材料，是理想的高性能吸附材料。本项目针对石墨烯针对浮选废水中有机药剂和重金属离子难以被同时有效除去的难题，将石墨烯水凝胶作为吸附剂来对浮选废水进行综合处理，同时考虑到成本对石墨烯基材料应用的限制，将未提纯的隐晶质石墨直接用于石墨烯水凝胶的制备，通过对石墨烯水凝胶多孔结构的表征以及其石墨化结构和氧化官能团的研究，揭示石墨烯水凝胶同时处理有机药剂和重金属离子的结构基础。吸附模型的建立分析石墨烯水凝胶吸附重金属离子和有机药剂的机制，建立石墨烯水凝胶综合处理多组分污染物的最优条件策略。本项目通过工艺矿物学自动分析仪对隐晶质石墨中杂质的种类及赋存状态进行分析，结合X射线衍射光谱检测制备GrO和GO过程中杂质含量的变化情况，探明了杂质的迁移规律。通过采用表面活性剂辅助剥离，在尽量保障石墨烯水凝胶中石墨烯化结构完整的同时提高低氧化度氧化石墨的剥离效率。选取一系列不同种类的表面活性剂进行辅助剥离试验，研究表面活性剂荷电状态及结构变化对剥离效率的影响，以及对后续rGOH制备过程中其多孔结构的调控机制。结果表明阴离子表面活性剂的剥离效率要好于阳离子型表面活性剂且对rGOH的孔隙结构影响较小。通过吸附实验考察pH、温度和污染物浓度对rGOH的吸附能力的影响，并结合动力学模型拟合、颗粒内扩散模型拟合和等温吸附模型拟合分析不同污染物在rGOH上的吸附行为机制。通过红外光谱和X射线光电子能谱检测污染物与rGOH表面的相互作用形式，探明了rGOH对Pb2+、Cd2+和丁基黄药的吸附机理，对低维矿物材料在矿山环境治理领域的应用具有重要的理论意义和实际价值。