强酸废水中复杂重金属离子在系列新型吡啶基螯合树脂上高选择性分离去除的微观机制与强化调控

Selective separation towards heavy metal from high-acidity solutions can benefit for resources reuse of inorganic acid and reduction of inorganic salt. According to lots of difficulties in effective removal and selective separation for such typical heavy metal ions (HMIs) as Cu(II), Ni(II), Co(II), Zn(II), Fe(II), series of pyridyl chelating resins (PNPY) which are acidity-resistant and targeted will be innovatively designed and completely characterized. The adsorption and separation behavior towards HMIs onto PNPY will be systematically explored by carrying out the sole-/binary-/multiple-component static and dynamic experiments under the complex conditions of strong acid and different anions. The separation processes and interactive characteristics will be illuminated qualitatively and quantitatively to establish structure-function relationships among PNPY physicochemical structure, HMIs characteristics, acidity or different anions of solution and so on. Base on structural evolutions and mathematical models, superior chelating modes and stable ligand configuration will be identified, which will help reveal the micro-mechanisms behind the highly effective removal and selective separation towards HMIs under different acidity and anions at molecular and ion levels. The interactive mechanisms involving coordination bonds, electron-withdrawing groups and feedback π-bond to pyridine groups will be further elucidated. Moreover, the multi-step control principles involving separation mechanisms and optimal factors for HMIs onto PNPY will be illuminated as to the effective integrated technique. The work would support both theoretical and technical guidance on the optimization and combined application of PNPY, and especially on the novel technique to selectively remove and exclusively recover HMIs from high-acidity solutions.

强酸废水中重金属分质回收后有利于无机酸的资源化、无机盐的减量化。围绕酸洗等行业大量强酸废水中复杂重金属（铜、镍、钴、锌、铁等）的高效去除及选择分离难题，研制、表征具有耐强酸、靶向特性的系列新型吡啶基螯合树脂PNPY，系统阐释其在强酸、不同阴离子体系下对典型重金属离子的单、双、多组份静态、动态分离行为规律，定性定量描述选择分离过程与交互影响特性，与树脂理化结构、重金属特征、溶液酸度、阴离子类型等建立构效关系，并结合固相结构演变、数理模型计算，确定主导螯合作用构型，在分子、离子水平上定性定量揭示强酸条件下重金属离子高效分离去除的微观机制，阐明多种重金属配位键、不同吸电子基及其对吡啶基反馈π键的交互影响机制。阐明强酸废水中重金属离子的梯级分离规律及优控环境因素，揭示多级分离集成技术的分质强化调控机制，为强酸废水中复杂重金属离子选择去除与分质回收、PNPY树脂优化优选与优控集成提供理论和技术指导。

针对强酸废水中重金属及无机酸资源化处理需求及选择性分离难题，以Cu(II)、Ni(II)、Co(II)、Pb(II)、Zn(II)等典型重金属离子作为模板污染物，设计制备适于强酸（pH＜3.0）条件下复杂重金属离子选择性分离去除的系列新型耐酸螯合树脂和凝胶类吸附剂。基于吸附量、吸附速率、选择性分离系数等参数定量描述强酸条件下系列吸附剂对双、多组分体系中重金属离子的选择分离特性以及交互作用特性，并与吸附剂理化结构、重金属离子特性以及酸度等建立构效关联，结合系列表征方法和理论计算揭示强酸条件下系列吸附剂与重金属离子结合的主要结合位点、主导作用构型与交互影响微观机制，为强酸性复杂重金属离子体系水体分质分离、多级调控处理提供理论指导。