水稻土中有机质介导的多氯联苯脱氯机制研究

项目名称： 水稻土中有机质介导的多氯联苯脱氯机制研究

项目编号： No.41271334

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 天文学、地球科学

项目作者： 沈超峰

作者单位： 浙江大学

项目金额： 75万元

中文摘要： 持久性有机污染物多氯联苯（PCBs）在全球范围内广泛迁移，面积广大的水稻土是其重要的受纳体。高氯代PCBs在环境中极难降解，须脱氯为低氯代PCBs后方可进行矿化。已有研究表明水稻土还原条件下PCBs可较快脱氯，但具体机理不明。一般环境中，PCBs化学脱氯缺少强还原性物质，微生物脱氯则缺少持续电子供体且电子传递效率低，水稻土厌氧环境及丰富有机质条件可克服以上瓶颈。本研究借助微电极、电反应池、同步辐射及基于非培养的宏基因组、PCR-DGGE、FISH、real-time PCR等分子生物学技术，探索水稻土中溶解性有机质对PCBs的敏化光解，研究有机质矿化提供电子供体、腐殖质穿梭提高电子传递效率的PCBs微生物高效脱氯机理，以此揭示水稻土中有机质介导的PCBs脱氯机制。希望能为阐明水稻田等湿地厌氧环境下氯代有机物自然衰减机理提供新的思路，也为氯代有机物污染场地的人工湿地修复提供理论依据。

中文关键词： 水稻土；多氯联苯；脱氯；有机质；生物修复

英文摘要： Polychlorinated biphenyls (PCBs) are typical widespread persistant organic pollutants all over the world. The vast area of paddy soil is an important sink for these compounds. High-chlorinated PCBs in environment is extremely difficult to be degraded, needing to be reductively dechlorinated to lower chlorinated PCBs before it could be carried out for aerobic mineralization. It has been proved that PCBs could be reductively dechlorinated effectively in paddy soil, though the mechanisms are still unknown. In ordinary environment, PCBs could not be chemically dechlorinated for absence of strong reducing substance. Meanwhile PCBs were also hard to be microbial-dechlorinated as the absence of sustained electron donor or the low efficiency of electron transport. The rich organic matter and the anaerobic environment may be the key which improves the PCBs dechlorination in paddy soil. With the help of microelectrode, synchrotron radiation, electric reaction cell and non-culture-based molecular ecological analysis such as metagenomics, PCR-DGGE, FISH, real-time PCR, the mechanisms of PCBs dechlorination in paddy soil will be studied on sensitization photodegradation by dissolved organic matter, sustained electron donor offering by organic matter mineralization, electron transport enhanced by humus shuttle. This work will

英文关键词： Paddy soil；Polychlorinated biphenyls；Dechlorination；Organic matter；Bioremediation