磁性光敏温敏水凝胶吸附剂对水中典型PPCPs的吸附/解吸行为表现及机制研究

Recent studies show that some problems exist in safety and security of water about typical PPCPs removal by means of adsorption, and these problems are associated with: 1)low adsorption efficiency due to limited adsorption sites in adsorbents, 2)high energy consumption resulted from desorption 3) and secondary pollution caused by external leachate. Thermo- responsive hydrogel, a novel macromolecular material, has been reported to be capable of reversible hydrophilic and hydrophobic change in response to external stimuli. They can be a class of promising thermo-responsive adsorbents after modification (e.g., functional design). The objective of this research is to develop adsorbents with high adsorption efficiency and quick stimulation response for typical PPCPs removal in water. We will incorporate hydrophilic / hydrophobic monomer which can increase hydrogen bonding and hydrophobic interaction, weak interaction, and Fe3O4 nanoparticle, possessing the ability of absorbing light energy and magnetic energy to convert them into heat, into conventional thermo- responsive hydrogels (which can be made with a mature preparation technology) to develop light-and thermo-responsive smart hydrogels. We will then use these hydrogels for PPCPs adsorption to: 1) improve efficient adsorption sites and adsorption efficiency, 2) achieve quick response to light and magnetic stimuli , 3)decrease desorption energy. We will characterize the hydrogels, including composition, structure, adsorption capacity with sensitivity and investigate their behavior in both batch and column adsorption. Furthermore, we will explore the fundamental relationships among the physicochemical properties of hydrogels and adsorption/desorption performance to fill the knowledge gap of adsorbents with high performance and to extend smart hydrogel applications in the environmental field.

水质安全中关于典型药物和个人护理品（PPCPs）这类新兴污染物的吸附去除存在因有效吸附位点不高造成的吸附效率低，解吸能耗高以及外加淋洗液产生二次污染的问题。温敏智能水凝胶，在外部环境刺激下，能发生可逆的亲疏水变化，经功能设计，是一种极具潜力的温敏吸附材料。本项目旨在制备去除水中PPCPs的磁性光敏温敏水凝胶吸附剂，一方面，引入能增强氢键作用或疏水作用这类非共价键弱作用力的亲水或疏水单体，增加有效吸附位点，提高吸附效率；另一方面，引入Fe3O4磁性纳米粒子，利用其吸收太阳光致热和磁致热效应促使凝胶快速升温，发生相变而解吸PPCPs，降低解吸能耗。表征凝胶组成、结构与刺激响应性之间的关系，揭示其在静态、动态吸附中的行为表现，阐明其理化特性与吸附/解吸行为的内在机理，为功能吸附剂的高性能化提供新的方法和理论基础，同时拓展和丰富智能水凝胶在环境领域的应用。

PPCPs在水体中的频繁检出和其潜在的危害，对生态环境和人体健康构成了潜在威胁。PPCPs 在水中的浓度低、种类多、物理化学性质复杂多样，吸附是一种有效去除方法。吸附剂的效能取决于吸附剂与吸附质之间的作用力。本项目制备了去除水中PPCPs的磁性光敏温敏水凝胶吸附剂，主要包括PNIPAM/CS@Fe3O4, PAC/CS/PVA, CdS/TiO2, CdS/Fe3O4/TiO2, g-C3N4/CS/PVA 等类型。这些吸附剂引入了能增强氢键作用或疏水作用这类非共价键弱作用力的亲水或疏水单体，增加有效吸附位点，提高吸附效率；同时，引入Fe3O4磁性纳米粒子，利用其吸收太阳光致热和磁致热效应促使凝胶快速升温，发生相变而解吸PPCPs，降低解吸能耗。表征了凝胶组成、结构与刺激响应性之间的关系，通过静态和动态吸附实验，考察了吸附剂的影响因素、吸附热力学、吸附动力学、吸附等温线，阐明了其理化特性与吸附/解吸行为的内在机理，为吸附剂的高效开发提供了有益的探索。