水生植物及根系微生物对废水中痕量离子液体的原位去除效能和机理研究

The unique properties of ionic liquids makes them attractive for a wide range of industry applications, thus resulting in their potential exposure into environment. Once the ionic liquids enter the ecosystem, it is very difficult to utilize the chemical processes to remove or degrade ionic liquids from the aquatic or terrestrial environments. Therefore, it is important to develop the environmental nondestructive bioremediation technologies based on microorganisms and vegetative plants. This project is planning to investigate the combined effects of aquatic plants and rhizospheric microorganism on the removal and biotransformation of ionic liquids in the water. This project will investigate ionic liquid migration, root assimilation, transportation and accumulation in the different part of plant-microorganism combined system. For this purpose, we will analyze the possible metabolism of ionic liquids in the different parts of plants; to monitor the evolution of ionic liquids in the water and rhizosphere and to investigate its relation with the diversity of rhizosphere microorganisms and accumulation in plants; to investigate the toxic effects of different concentration and different chain length of ionic liquids on the plant growth and other biochemical characteristic of plants tissues.The results from this work are expected to provide theoretical fundamentals and technical support for effective removal of ionic liquids in the water by introducing the highly efficient and in-situ removal methods like contructed wetland and thus forming a synergetic remediation system in rhizosphere.

离子液体具有化学稳定性极高、导电性强、挥发性低等特点，是一种"绿色溶剂"，被广泛用于化学反应、生物技术等领域。随着它的广泛使用，国内外研究者逐渐认识到离子液体对环境具有潜在危害，因而如何从环境中去除离子液体，并探究其去除机理已成为研究热点。目前植物-微生物修复去除水体中离子液体类污染物的研究十分有限，还未见植物及微生物对离子液体的吸收、转移和去除的研究报道。本课题拟以咪唑类离子液体为研究对象，利用水生植物去除水中痕量的离子液体，探讨植物对不同链长离子液体的吸收动力学特性，并比较研究去除动力学存在差异的内在机制；揭示离子液体在沉积物-微生物-植物耦合体系中吸附、迁移和转化规律，通过对中间产物进行系统的表征分析，阐明离子液体在植物-微生物耦合系统中的降解机理和代谢途径，科学阐述人工湿地系统对离子液体类污染物的去除能力与作用机理，为水体中离子液体类污染物的高效治理提供新的科学技术原理。

由于离子液体具有难挥发性、化学和热力学稳定性和极易水溶性等特性，导致其在水环境和土壤环境中难以降解、容易积累和产生生态毒性效应等方面的潜在风险。本课题以咪唑类离子液体作为研究对象，黑麦草原位去除水体中离子液体的能力，确定了1-丁基-3-甲基咪唑在黑麦草体内的降解产物及降解途径，揭示了黑麦草去除、降解咪唑类离子液体的机理。比较研究了不同链长离子液体对黑麦草体内分布、积累特性，阐明了链长对植物去除效率的影响机理。最后，考察研究了人工湿地对咪唑类离子液体的去除能力，实现了水体中痕量离子液体的原位强化去除。