结构型掺杂碳材料去除重金属离子的性能及其资源化再利用研究

The adsorption technique for removing heavy metal from the industrial wastewater is considered to be an effective method on the environmental treatment. It is highly significant to develop novel adsorbent with high adsorption capacity and stability to save the cost. In this project, the novel monolith carbon based materials will be prepared and applied as the adsorbents, while typical heavy metal ions, such as Cr(VI)/ Cr(III), Pb2+, Cu2+and Cd2+ were selected as model contaminants. The universal mechanism of the heavy metal removal over the monolith carbon-based materials will be fully investigated. The evaluations of the adsorption kinetics, enthalpy change rule, adsorption free energy and adsorption capacity will be carried out to investigate the interaction between the heavy metal ions and the monolith carbon materials with the tunable chemical/physical surface. The nontoxic and reductive metal particles will be introduced to change the valence state of heavy metal ions, and enhancing the heavy metal removal performance. The bonding behavior during the adsorption process, variation of ions valence, and coupling mechanism between the surface functional group of materials and heavy metal ions are going to be studied by the in-situ technologies. The re-utilization of the used carbon adsorbents as the catalysts on the electrochemical reduction of CO2 will be systematically studied. On the basis of aforementioned discussions, the essential relationship among the monolith carbon-based materials, high efficiency for the heavy metal removal and electrochemical performance can be summarized.

吸附技术是用于去除工业废水中重金属离子的有效手段，开发新型吸附剂以增强吸附能力、提高回收效率和回收利用价值具有重要意义。本项目拟采用结构型掺杂碳材料为吸附剂，以铬、铅、铜和镉等重金属离子为模型污染物，深入探索结构型掺杂碳材料吸附治理剧毒重金属离子的共性机理；通过对吸附动力学常数、吸附级数常数、吸附自由能、吸附能力等的研究，确定结构型掺杂碳材料表面的物理/化学性质对重金属离子吸附作用的调控能力；以原位光谱技术探究吸附成键行为、离子价态演变规律和碳材料表面功能团与金属离子的耦合机制；针对碳吸附剂的再生和资源化再利用（作为催化剂应用在CO2电化学还原领域）进行系统的研究，总结结构型掺杂碳材料-重金属去除效率-电化学性能的相互关系。

采用吸附的方法去除水中的重金属离子，能有效治理工业废水中的重金属污染，并实现重金属离子的回收。本项目设计了一款用于电吸附重金属离子的装置，以成型碳为吸附剂。通过施加电场，可将水体中的重金属离子完全吸附，施加反向电场时，可将吸附的重金属离子脱附出来，实现重金属离子的回收。使用的吸附剂为成型碳材料，材料本身对水体无污染，当吸附的重金属离子被脱附出来后，吸附剂可重复利用。通过对六价铬离子（Cr6+）和铜离子等的吸附去除，在较低电场的作用下，均体现出良好的效果。当吸附饱和后，通过接入反向电场可有效地脱附碳材料表面吸附的金属离子。通过原位吸-脱附铬离子10次后，脱附的金属离子可以被富集到另一溶液中，可以实现对金属离子的去除与回收再利用。除此之外, 我们还在碳基材料在能源与多相催化领域进行了拓展研究。结果显示，当以氮掺杂碳材料为催化剂时，碳材料表面的物理化学性质、负载的金属颗粒对表面电子传递作用具有良好的调控效应，使得该材料具有较好的光催化产氢活性。同时，碳材料表面官能团对烃类的液相催化氧化催化过程亦具备较好的效果。通过调控催化剂表面的电子转移行为，可以有效改善以碳为催化剂的多相催化性能。