根际土壤中持久性有机污染物（POPs）的形态及转化是制约其生物可利用性和生物修复效率的最关键因素之一。以往有关有机污染物形态的研究，主要集中于几种农药类化合物；而关于植物根系分泌的低分子量有机酸（LMWOA）对根际POPs形态转化的影响，国内外则少有报道。本项目以多环芳烃(PAHs)为对象，系统地研究了LMWOA对土壤中PAHs形态转化的影响。主要成果：建立了土壤中PAHs形态分级的连续提取方法，将其分为可脱附态、有机溶剂提取态、结合残留态；系统地阐明了"老化"土壤中PAHs的形态及转化规律；揭示了LMWOA对土壤中PAHs形态及转化的影响；从土壤中PAHs活化的角度，探明了LMWOA对PAHs吸附固持的影响，分析了LMWOA影响土壤中PAHs形态及转化的机理。发表论文10篇，其中SCI论文7篇（影响因子>4.0的3篇）。研究成果可为调控土壤中POPs有效性、减低植物污染风险、提高修复效率等提供重要资料和依据。依托本项目，培养研究生3名；促进了青年学者成长，项目主持人2010年获霍英东教育基金会第十二届高等院校青年教师基金，2010年11月获第二届中国土壤学会优秀青年学者奖。

The forms of persistent organic pollutants (POPs) dominate their availability and rhizoremediation efficiency in soils. In last decades, most studies focus on the forms of pesticides, and little information is available on the impacts of root-secreted low-molecular-weight organic acid (LMWOA) on the forms of POPs in soil environment. Polycyclic aromatic hydrocarbons (PAHs) are a group of POPs concerned worldwide and found commonly in soils. In this project, a novel fractionation method of PAHs in soils was proposed, and the forms of PAHs were fractionated into the desorbing fraction, non-desorbing fraction, and bound residue. Utilizing this method, the forms of PAHs in aging soils were elucidated. The effects of LMWOAs on the form and its transformation of PAHs in rhizosphere were clarified utilizing the microcosm and batch equilibrium technique. Basing on the observations of the sorption and the activation of PAHs in soil in the presence of LMWOAs, the mechanism of the impacts of LMWOAs on the the form and its transformation of PAHs in rhizosphere were defined. Results of this project provide new information on the availabilities of POPs in rhizosphere, and benefit the rhizoremediation, food security, and human health. 10 journal papers including 7 international journal papers involved in SCI data base were published, and 3 graduates involved in this project. In the duration of this project, Dr Gao won the 2nd Outstanding Young Researcher of Soil Science Society of China in 2010.

根际土壤中持久性有机污染物（POPs）的形态及转化是制约其生物可利用性和生物修复效率的最关键因素之一。以往有关有机污染物形态的研究，主要集中于几种农药类化合物；而关于植物根系分泌的低分子量有机酸（LMWOA）对根际POPs形态转化的影响，国内外则少有报道。本项目以多环芳烃(PAHs)为对象，系统地研究了LMWOA对土壤中PAHs形态转化的影响。主要成果：建立了土壤中PAHs形态分级的连续提取方法，将其分为可脱附态、有机溶剂提取态、结合残留态；系统地阐明了"老化"土壤中PAHs的形态及转化规律；揭示了LMWOA对土壤中PAHs形态及转化的影响；从土壤中PAHs活化的角度，探明了LMWOA对PAHs吸附固持的影响，分析了LMWOA影响土壤中PAHs形态及转化的机理。发表论文10篇，其中SCI论文7篇（影响因子>4.0的3篇）。研究成果可为调控土壤中POPs有效性、减低植物污染风险、提高修复效率等提供重要资料和依据。依托本项目，培养研究生3名；促进了青年学者成长，项目主持人2010年获霍英东教育基金会第十二届高等院校青年教师基金，2010年11月获第二届中国土壤学会优秀青年学者奖。