氯代烯烃类污染物是污染地下水中检出率最高的污染物之一。在众多修复技术中，自然衰减及强化自然衰减技术以其经济费用低的独特优势被应用于不同污染场地的修复中。在自然衰减的各种作用中，只有微生物降解作用可将污染物彻底转化和去除。因此对该过程中微生物降解效能的评价是至关重要的。本项目以三氯乙烯（TCE）为研究对象，结合化合物特殊稳定同位素分析（CSIA）和聚合酶链式反应(PCR)这两种新型环境分子诊断技术，对TCE污染地下水生物降解效能进行评价。探讨在不同条件下，三氯乙烯及其代谢产物在降解过程中，碳、氯稳定同位素比变化规律，微生物群落结构演变规律，功能微生物密度、功能基因拷贝数、功能微生物活性变化规律。从而揭示不同水文地质条件、环境条件、外源激活因子与微生物作用之间的耦合关系。通过新型基质消耗动力学模型的建立，预测TCE污染场地生物降解规律。为TCE污染场地生物修复评价、过程管理提供理论和方法依据。

The chlorinated alkenes are one of the most common organic pollutants detected in contaminated groundwater. Monitored natural attenuation (MNA), as well as enhanced natural attenuation (ENA) obtain much attention among numerous of remediation techniques and are widely used in remediation of contaminated sites due to their low-cost. However, microbiological degradation is the only known natural attenuation pathway which pollutants can be transformed and breaked up. Therefore, evaluating the microbial degradation efficiency in this process is crucial. In this project, TCE was selected as the target pollutant to evaluate the in situ microbial degradation efficiency of the TCE contaminated groundwater by combining two new environmental molecular diagnostic techniques, CSIA and PCR. Changes of stable carbon and chlorine isotope ratio, microbial community structure and variation, functional microbial, copy numbers of functional gene and activity of functional microbial will be analyzed in the processes of degradation of TCE and its metabolic intermediates. The relationships between the different hydrogeological condition , environment condition, exogenous activating factor and microbial action will be revealed. New dynamics model of substrate consuming also will be established to forecast the biodegradation law of the TCE contaminated site. Correlative achievements acquired above can be a potential theory and method basis for the evaluation and management of bioremediation of TCE contaminated site.