基于软碱配位基的协同配位吸附材料重金属深度净化及构效关系研究

The acidic heavy metal wastewater discharged by our smelting enterprises has serious environmental pollution. The current adsorptive material has weak coordination capacity, and the pH value suitable for adsorption is generally 5-6 or even higher, then such wastewater cannot be directly treated. How to effectively control the pollution of industrial waste water containing heavy metals and realize the utilization of heavy metals is an urgent problem in China. In this application, a new idea of deep purification of heavy metal ions in acidic wastewater based on multi-group coordination mechanism was proposed. We will study (1) Design and construct new adsorption materials based on the strong interaction between soft ligands and heavy metal ions and also ion association and neutral complexation synergistic coordination mechanism according to the coordination structure characteristics of heavy metal ions, and establishes controllable preparation methods of new materials by ion imprinting and crosslinking casting technology. (2) Study on the effects of components, content, structure of the prepared materials and solution environment on the adsorption performance of heavy metal ions, investigate the adsorption characteristics and mechanism, and also the structure-effect relationship and key influencing factors. The aim is to establish a new method of synergistic coordination and deep removal of heavy metals from wastewater, achieve efficient adsorption and recovery of heavy metals under acidic conditions, and enrich the basic theoretical system for deep purification of heavy metal wastewater.

我国冶炼企业产生大量酸性重金属废水，当前的吸附材料配位能力弱，适合吸附的pH值一般5-6，甚至更高，不能直接处理此类废水，如何高效控制含重金属工业酸性废水污染、实现重金属的资源化利用是当前亟待解决的问题。本项目提出多基团协同配位深度净化酸性废水中重金属离子的新思路，拟研究（1）根据重金属离子的配位结构特点，利用软碱配位基与重金属离子的强相互作用以及离子缔合和中性络合协同机制设计构筑吸附新材料，采用离子印迹和交联铸型研究设计材料的可控制备方法；（2）研究制备材料中组分、含量、结构以及溶液环境等因素对重金属离子吸附性能的影响，研究吸附特性和机理，剖析构-效关系和关键影响因素。旨在建立重金属协同配位与深度净化新方法，实现酸性废水中重金属的高效吸附与回收，丰富重金属废水深度净化的基础理论体系。

酸性重金属废水的处理一直是矿山、冶金行业的难题，开发可直接用于选择性深度去除并回收酸性废水中重金属的吸附材料具有重要的学术价值和实际意义。本项目利用软碱配位基与重金属离子的强相互作用构筑制备了7种硫代官能团吸附材料。研究了材料对铅和铬重金属离子的吸附动力学、热力学及吸附机理。研究的吸附材料可以在低pH范围使用，与其它吸附剂相比，能够实现在pH=3的酸性条件下对Pb(II)和Cr(VI)吸附，吸附Pb(II)平衡时间为25 min，吸附Cr(VI)的平衡时间为10 min，与其它吸附剂相比平衡时间大大缩短，且吸附量明显提高。.设计中性及碱性环境中具有对铬酸根具有强吸附能力的材料是一个重大的挑战。本项目根据HCrO4−和CrO42−结构，通过DFT计算，设计制备了4种具有预组织构象的季铵盐吸附材料，并研究了不同条件下材料的吸附性能。双子季铵盐DPS-GO、ETMEDA-CMCPS及QPVBCl对Cr(VI)的吸附过程不受pH的影响，pH=7.0时，ETMEDA-CMCPS最大吸附容量为89.77mg/g，pH=8.0时，QPVBCl最大吸附容量为136 mg/g，均高于已报道的吸附剂。实现了中性甚至弱碱性条件下铬酸根的去除。.合成了三种磷酸酯基功能化的吸附材料，超亲水性聚苯乙烯磷酸酯树脂（PSP）为多孔材料，能够实现pH=4酸性条件下对Pb(II)的高效吸附，饱和吸附量为160.25 mg·g-1。聚乙烯醇磷酸酯超吸水树脂（PVAP）为大孔海绵结构，能够实现pH=3酸性废水中对Pb(II)的高效吸附，饱和吸附量为558.66 mg·g-1。β-环糊精磷酸酯聚合物（β-CDPP）能够实现pH=3酸性废水中对Pb(II)的高效吸附，饱和吸附量为516.00 mg·g-1。三种吸附剂都具有高的吸附效率，半小时内即可达到吸附平衡，且能够循环利用。.研究的软配位基以及磷酸基吸附材料解决了酸性条件下重金属污染物去除效率较低、难以深度净化的问题。预组织结构双子季铵盐吸附剂实现了中性甚至弱碱性条件下铬酸根的去除，为阴离子污染物的分离提供了一条新的思路。