砷和苯并(a)芘在沉积物固-液界面的化学-微生物交互作用机制研究

The behaviour and fate of heavy metals along with polycyclic aromatic hydrocarbons (PAHs) are significantly affected by their interaction, speciation and transformations at water sediment interfaces. The regulations and mechanisms of interaction between heavy metals and PAHs have not been fully understood thus far. The description of metabolic pathways of PAHs in the presence of heavy metals is unknown. As(Ⅲ) and benzo(a)pyrene (BaP) were chosen as typical pollutants from Jinzhou Bay to investigate their interaction mechanisms related to chemical microbiology at the solid-liquid interface of the sediment. New types of organo-metallic compounds/complexes are expected to be generated due to the interaction between the metabolites and As(Ⅲ) whose process will be monitored via isotope labeling. A new concept of multiple catalysis degradation is proposed and will be explained through this proposed work. Furthermore, a new methodology will be established for the separation and identification of organic metal compounds in sediments. As(Ⅲ) oxidation and redistribution after As(Ⅲ) oxidation at the solid-liquid surface of the sediments will be analyzed and interpreted. X-ray Absorption Spectroscopy, X-ray Diffraction, Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy and Micro-Raman Spectroscopy will be employed to reveal the transformations and fate of As(III) and BaP at the molecular-level. Successful implementation of this project will help to further study and predict the fate of combined pollution sediments.

重金属和多环芳烃作为沉积物中两类典型持久有毒污染物，与沉积物中兼性厌氧微生物的交互作用强烈影响其固液界面行为及其环境归趋。目前这种交互作用规律与过程机制一直未得到清晰、全面的认识。本项目以锦州湾沉积物中As(III)和苯并(a)芘（BaP）为典型污染物，运用同位素标记方法,系统研究在As(III)影响下BaP的兼性厌氧微生物降解过程和代谢途径，鉴定BaP的主要代谢产物与As(III)交互作用后生成的有机金属化合物的分子结构，提出并诠释交互作用过程中“多元催化降解”新概念，同时建立沉积物中有机金属化合物分离鉴定新方法；阐释BaP降解过程对As(III)氧化及其固液再分配的影响，并利用XAS、XRD和Raman等手段从分子尺度揭示交互作用后As(III)和BaP在沉积物固-液界面的变化和归趋。项目的成功实施既可以丰富复合污染的地球化学循环理论，也可以为我国水环境复合污染的治理技术提供理论依据。

重金属和多环芳烃作为沉积物中两类典型持久有毒污染物，与沉积物中兼性厌氧微生物的交互作用强烈影响其固液界面行为及其环境归趋。本项目运用同位素标记方法,以锦州湾沉积物为研究对象，系统研究了沉积物中As(III)/(v)、BaP、洛克沙砷（ROX)污染物在单一或复合污染条件下的竞争吸附，以及As(III)/(v)影响下BaP和ROX的降解过程和代谢途径以及复合污染物的去除技术与机理；同时探讨微生物共代谢底物（水杨酸、琥珀酸钠和菲)和表面活性剂（TW80）对降解菌的酶蛋白应答，确定关键降解酶，从简单至复杂体系，系统研究交互作用后As和BaP在沉积物中的赋存形态、变化和归趋；根据交互作用过程、现象和数据分析提出并诠释交互作用过程中“多元催化降解”新概念。项目的成功实施既可以丰富复合污染的地球化学循环理论，也可以为我国水环境复合污染的治理技术提供理论依据。