持久性有机污染物的超分子识别及其可生物利用性研究

Remediation of persistent organic pollutants (POPs) contaminated soil is a hot research and a tough job in environmental field. The main difficulty is that POPs exist in soils are in an adsorbed form and difficult to be biodegradated, which results in a low efficiency of bioremediation. It has been proved recently that supermolecule hydroxypropyl-β- cyclodextrin（HPCD） has the ability to enhance the transport of polycyclic aromatic hydrocarbons (PAHs) in soils and efficiency of bioremediation. However, most of them focused on easily biodegradated PAHs such as phenanthrene. It is lack of systematical study for more hydrophobic and more toxic POPs until now. So the function of supermolecule on bioremediation of POPs would be researched by combining molecular simulation with laboratory research in this project. Firstly, molecular modeling technique is used to establish the platform and evaluation criteria on molecular recognition between cyclodextrin and its derivatives(CDs) and typical POPs contaminants, and obtain water solubility evaluation system of CDs and its inclusion complexes with POPs. Then, the relationships between CDs inclusion capacities for POPs and desorption rates of POPs from soil, bioavailability of POPs that form complex with CDs would be obtained. These results would provide theoretical basis for evaluating the feasibility of CDs application in enhancing bioremediation of POPs contaminated soil.

持久性有机污染物（POPs）污染土壤修复技术的研究是环境领域的研究热点和难点。主要难点在于POPs以吸附态存在于土壤有机质中，很难被生物利用，生物修复效率极低。虽然近期研究者们发现超分子羟丙基β环糊精能够提高土壤中多环芳烃类污染物的传输能力，加快土壤生物修复效率，但研究工作大多局限于菲等土壤中较易生物降解的污染物，对疏水性及生物毒性更强的POPs还缺乏系统深入的研究。本研究的主要目的是将分子模拟方法与生物降解等实验研究紧密结合，首先利用分子模拟技术建立评价环糊精及其衍生物（CDs）与典型POPs污染物间超分子识别作用的技术平台，建立相互作用力的评价标准；建立CDs及其与POPs包结物的水溶性评价体系；在此基础上获得CDs对POPs的包结能力与土壤POPs的脱附率、与包结POPs可生物利用性的关系，为评价CDs在增强POPs污染土壤生物修复中应用的可行性提供依据。

本项目聚焦于持久性有机污染物(POPs)污染土壤修复技术这一环境领域的研究热点和难点，为突破当前研究局限于少数几类环糊精以及菲等简单污染物的现状，将分子模拟方法与生物降解等实验研究紧密结合，对影响环糊精及其衍生物（CDs）对POPs超分子识别和可生物利用性的重要因素和机理进行了探索性的研究。在国家自然科学基金面上项目的资助下，按计划建立和优化了评价CDs与POPs超分子识别的分子模拟技术，研究了多种CDs体系与POPs客体分子相互作用的机制，研究了多种溶液和细胞膜体系下CDs与客体分子的分子动力学特性，评价了CDs对POPs包结能力与土壤POPs脱附率和可生物利用性的关系，针对POPs进行了CDs库的虚拟筛选研究，并进行了实验验证。研究结果表明：CDs的典型主客体分子识别体系可以有效的识别和包结作用于POPs分子，分子间作用力对CDs超分子识别能力有重要影响，CDs的不同类型侧链对其包结能力有直接影响。分子动力学研究诠释了不同体系下POPs可生物利用性的影响因素，通过对CDs库的虚拟筛选发现了对POPs兼具良好水溶性、包结能力和可生物利用性的磺丁基-β-CD（SBE)。为建立完整的CDs对POPs包结能力和土壤中POPs脱附能力的评价模型，CDs和POPs分子属性对该体系超分子识别能力的影响仍需要更深入的研究。