【作者】 刘贵春；

【导师】 李建华； 黄清辉；

【作者基本信息】 同济大学 ， 环境科学， 2008， 硕士

【摘要】 长江口是上海市的重要水源地，长江口水源地的持久性有机污染研究对保障上海市饮用水水质安全有极其重要的意义。本文以长江口战略水源地及周边区域为研究对象，对其水体和表层沉积物中的有机氯农药(OCPs)、多环芳烃(PAHs)和多氯联苯(PCBs)从化学分析和生物毒性测试两种角度进行研究，以期能够真实地反映持久性有机污染的现状。本文采用GC-uECD和GC-MS对有机氯农药、多氯联苯和多环芳烃进行定性和定量分析。表层沉积物样品的化学分析结果表明，20种OCPs的总量为0．46～12．09 ng／g，主要为HCHs和DDTS两类，组分特征分析表明其主要为早期的农药残留；20种PAHs的总量为59．6～4176．0 ng／g，其中以低环类为主，分子量指数法和异构体比值法分析表明PAHs主要源于石油的泄漏和石化燃料的燃烧。与其他地区相比，研究区表层沉积物中OCPs和PAHs的污染处于低到中等水平。表层沉积物中的PCBs污染较轻，仅在5个采样点检出较低含量和较少种类的PCBs。应用ERL和ERM值对研究区表层沉积物中的OCPs和PAHs进行生态风险浅析，结果发现，吴淞口样点的PAHs总含量和多数PAHs单体含量以及多数采样点的P,P′-DDT含量均处于ERL和ERM值之间，可能存在一定的生态风险。研究区表层沉积物中OCPs和PAHs含量的空间分布差异较大，大致趋势为南支南岸沿线>南航道>北航道，南岸的城市排污口和城市支流为OCPs和PAHs的主要贡献源，战略水源地区域沉积物中OCPs和PAHs含量最低，受岸边排污活动影响较小。研究还发现沉积物中的OCPs和PAHs含量与有机质含量之间存在良好的相关性，说明有机质含量是影响有机污染物分布的一个重要因素。青草沙、扁担沙和没冒沙三大战略水源地水体中OCPs和PAHs的化学分析结果表明，OCPs和PAHs含量较低，潮汐变化和空间分布特征说明其主要来源于长江径流，沉积物的再悬浮可能会加重水体的有机污染。本研究还对表层沉积物样品的提取液进行了EROD生物测试、重组基因酵母生物测试和SOS／umu生物测试，结果发现，南支沿岸的城市支流入口和排污口区域的Ah受体效应和雌激素效应明显，且具有遗传毒性，其中PAHs是Ah受体效应、雌激素效应和遗传毒性效应的主要贡献因子，OCPs对雌激素效应也有重要贡献。战略水源地区域的沉积物样品无明显的生物毒性效应。更多还原

【Abstract】 The Yangtze Estuary is one of the current water sources of Shanghai City. Research on persistent organic pollution in water sources of the Yangtze Estuary has significant meaning for safety drinking water supply in Shanghai City. In order to investigate the status of persistent organic pollution, this study collected water and sediment samples in strategic water sources of the Yangtze Estuary and its around areas, and analyzed organochlorine pesticides (OCPs), polycyclic aromatic hydrocarbons (PAHs) and Polychlorinated Biphenyls (PCBs) by chemical and biological methods.In this study, GC-μECD and GC-MS were used for qualitative and quantitative analyses of OCPs, PAHs and PCBs. The results for surface sediment samples showed that the total concentrations of 20 OCPs ranged from 0.46 ng/g to 12.09 ng/g, in which HCHs and DDTs were. the predominant components. The compositions of HCHs and DDTs indicated that they were mainly the early residues in the environment. The sum of 20 PAHs concentrations in surface sediments ranged from 59.66 ng/g to 4175.94 ng/g, which were mainly low molecular weight PAHs. Source analysis by molecular indices and ratio methods implied PAHs originated from petroleum leakage and petroleum combustion process. Compared with other areas, the levels of OCPs and PAHs in surface sediments of this study were low to moderate. PCBs pollution in surface sediments was lower, and only in 5 sampling sites were lower concentrations and less kinds of PCBs detected. Moreover, the effects range low (ERL) and effects range median (ERM) values were employed to assess ecological risk of OCPs and PAHs in surface sediments. It was found that the total 16 priority PAHs and most of individual PAH concentrations in Wusong Mouth and p,p’-DDT concentrations in most sites were above ERL but below ERM values, indicating potential adverse biological impacts.The spatial distribution of OCPs and PAHs concentrations of surface sediments varied significantly among sampling sites in this study, following the sequence: the south coast > the south waterway > the north waterway. The entries of urban sewage discharges and tributary river runoff along the south coast were the main sources of OCPs and PAHs; while the strategic water source sites had rarely been affected by discharging and had the lowest OCPs and PAHs concentrations in surface sediments. In addition, strong correlations were found between both OCPs and PAHs concentrations and organic matter content in surface sediments, which indicated organic matter content played an important role in distributing organic pollutants to study areas.OCPs and PAHs in water were analyzed in three strategic water sources of the Yangtze Estuary including Qingcaosha, Biandansha and Meimaosha. It was found that OCPs and PAHs concentrations were lower; the runoff of the Yangtze River was the source of pollutants; and sediment resuspension might aggravate organic pollution of water.Moreover, in this study sediment extracts were analyzed by a battery of in vitro bioassays including EROD bioassay, recombinant gene yeast bioassay and SOS/umu bioassay. It was found that samples in the entries of urban sewage discharges and tributary river runoff along the south coast showed significant Ah-receptor response, estrogenic response and genotoxicity response, of which PAHs was a main risk stressor. In addition, OCPs was a main risk stressor of estrogenic response. While samples of the strategic water source sites showed no significant bio-toxicity effects.更多还原