【作者】 张桂斋；

【导师】 李小明；

【作者基本信息】 山东大学 ， 环境工程， 2014， 博士

【摘要】 南四湖南四湖位于山东省西南部,是山东省最大的淡水湖,是南水北调工程的东线工程重要的输水通道和调蓄湖泊。南四湖有南阳湖、独山湖、昭阳湖和微山湖组成,被二级坝分成上级湖和下级湖,上级湖包括南阳湖、独山湖和部分昭阳湖,相对下级湖拥有较多的入湖河流。南水北调东线工程开通运行之后,南四湖水流方向发生改变,调水将从下级湖流入上级湖。因此南四湖的水质关系到整个东线工程水质状况,是影响南水北调东线水质的一个重要湖泊。近几年来,对南四湖水和表层沉积物中持久性有机物、重金属、营养盐N、P等做了大量研究工作。研究结果表明,南四湖水和表层沉积物都受到不同程度的污染,然而湖水和表层沉积物中污染物含量相对较低,南四湖污染状况处于低风险水平。但是这些研究主要是分别对南四湖沉积物和湖水的污染做了大量研究,系统对南四湖中水、沉积物、水生植物、水生动物的食物链中POPs和重金属的系列研究,还鲜见报道。南四湖作为我国北方最大的淡水湖,盛产各种鱼类、虾、螃蟹等水产品,并且有大量的水产养殖,这些水产品大量销售于国内外,也是当地居民喜爱的食物。因此,对南四湖水生食物链中展开持久性有机污染物和重金属的污染水平、生物积累和风险评价等系统研究工作,可为进一步评价该水体的污染及治理和生态系统健康预测提供参考数据,也可以为人类是否受到健康风险提供参考。研究内容主要包括以下几个方面：(1)分析研究南四湖食物链中有机氯农药、多环芳烃、重金属在空间分布概况；(2)对南四湖沉积物中有机氯农药、多环芳烃、重金属污染来源进行分析,判断污染物的主要污染来源；(3)分析研究南四湖食物链中有机氯农药、多环芳烃、重金属在南四湖水生食物链中的积累以及水生生物中污染物的积累和它们所处营养级之间的关系；(4)分析有机氯农药、多环芳烃、重金属在南四湖水、沉积物、水生动物的风险评价,是否对人类身体健康存在危害。运用带电子俘获检测器的气相色谱仪(GC-ECD)分析了南四湖水、表层沉积物、水生植物和动物(鱼和虾)中12种有机氯农药(OCPs)含量。经分析,水、表层沉积物、水生植物和动物中总的有机氯农药的浓度分别为：65.31-100.31ng/L、2.9-6.91ng/g,1.29-6.42ng/g.7.57-17.22ng/g。在南四湖食物链中,有机氯化合物的组成除了六六六和滴滴涕是主要的有机氯化合物外,七氯化合物也是主要的有机氯污染物。表层沉积物样品中六六六和滴滴涕的来源分析结果表明,南四湖表层沉积物中近期没有新的污染物来源,六六六的污染主要由于使用林丹造成的。运用生物积累因子(BASF)来表示水生生物中疏水性有机化合物在水生态系统中的积累状况。BASF定义为生物中脂肪含量标化后的有机化合物的浓度含量和有机碳标化后的沉积物中有机化合物的浓度含量的比值。菹草是南四湖主要的水生植物在所有采样点都有分布,因此,选择菹草(Potamogeton crispus Linn)、鱼和青虾(Macrobrachium nipponense)为代表性的水生生物来研究水生生物中有机氯化合物的生物积累。水生生物中有机氯化合物的生物积累的研究结果表明,滴滴涕和七氯化合物生物积累较高,其次是六六六和艾氏剂类化合物；鱼对有机氯化合物的生物积累能力明显高于水生植物和虾的生物积累能力。水生植物相对于鱼和虾处于较低的营养级水平,这表明有机氯农药在食物链中存在生物积累。在鱼样品中,乌鳢(Channa argus)的有机氯生物表层沉积物积累因子的值最高,其次是鲫鱼(Carassius auratus)和鲤鱼(Cyprinus caspio),这可能和鱼的生活习性和饮食习惯有关。乌鳢属于肉食性动物主要食用软体动物、虾、小的鱼类,偶尔食用水生植物。鲫鱼和鲤鱼食鱼杂食性动物,因此,从食性判断,乌鳢相对于鲫鱼和鲤鱼属于较高营养级水平。这一结果也表明,有机氯农药在食物链中存在生物积累。对南四湖水、沉积物、水生生物中有机氯的含量进行生态风险评价。南四湖水样中六六六和滴滴涕的平均浓度分别为：22.15ng/L和18.23ng/L,远低于GB3838-2002规定的地表水中六六六和滴滴涕的浓度,国标GB3838-2002中规定地表水中六六六和滴滴涕的浓度要低于5000和1000ng/L。这一结果表明南四湖的水环境是安全的。本研究中采用两种评价方法对沉积物中有机氯含量进行风险评价,一个是潜在生态风险的效应区间低值(ERL)和效应区间中值(ERM)；另一个是门槛影响值(TEL)和可能影响值(PEL)。评价结果表明最有可能对水生生物产生不利影响的有机氯化合物是环氧七氯,在所有采样点中有86%采样点的环氧七氯浓度高于TEL值,有14%采样点的环氧七氯浓度高于PEL值。南四湖表层沉积物环境处在较低的风险水平,但是要注意环氧七氯的对环境的影响。对南四湖生物中有机氯的风险评价是通过计算容许日摄取量和风险商的值来完成的。评价结果显示：HCHs的HR值大于1,表明日常食用南四湖鱼类,存在潜在致癌风险的概率大于百万分之一。依据南四湖水、表层沉积物和鱼肉中有机氯的风险评价结果可知,六六六和环氧七氯对人类健康的风险影响高于滴滴涕和狄氏剂类化合物。运用气相色谱-质谱联用测定了南四湖水、沉积物、水生生物中的多环芳烃。南四湖水、沉积物、水生植物和动物中多环芳烃的总含量分别为：27.54-55.04ng/L,80.31-639.23ng/g干重,20.92-192.78ng/g干重,和67.3-533.9ng/g干重。运用菲与蒽(Ph/An)、荧蒽与芘(Flu/Pyr)、低分子量(2-3环)多环芳烃与高分子量(4-6环)多环芳烃的含量比值(LMW/HMW)来判断南四湖沉积物中多环芳烃的可能来源。比值分析结果表明南四湖大多数采样点主要是化石燃料的不完全燃烧和石油源的混合污染。在南四湖水、沉积物和水生植物样品中多环芳烃的组成相似,都以2-3环多环芳烃化合物为主,而在沉积物中多环芳烃主要以4-6环多环芳烃化合物为主。在沉积物和水生植物中多环芳烃含量存在正相关关系,但是它们的多环芳烃的组成不同,这意味着水生植物从沉积物中吸收多环芳烃是有选择性的,多环芳烃化合物在水生植物中的积累是不同的。水生植物和鱼中的多环芳烃存在正相关关系,这一结论说明鱼中的多环芳烃主要是从水生植物中获取的,而不是主要直接从水中获得的。运用生物积累因子(BASF)来表示多环芳烃化合物在水生生态系统中的积累。在水生生物中低分子量的多环芳烃的生物积累因子要比高分子量的多环芳烃高,这说明低分子量的多环芳烃化合物在水生植物、鱼和虾中更容易被积累。在水生植物中光叶眼子菜(Potamogeton lucens Linn)和金鱼藻(Ceratophyllum demersum Linn)的总的多环芳烃化合物的生物积累因子高于大部分动物的生物积累因子；在南四湖鱼和虾中多环芳烃化合物的生物积累因子从高到低的顺序是：鲤鱼>青虾>鲫鱼>乌鳢,乌鳢属于食肉性动物,鲫鱼和鲤鱼是杂食性动物,因此,从食性判断乌鳢相对于鲫鱼、鲤鱼和虾处于较高营养级水平,但是在本研究结果中乌鳢的生物积累因子却是最低的,虾的生物积累因子仅低于鲤鱼,以上结论表明,在南四湖动物中多环芳烃化合物并没有沿着食物链由低到高进行积累。南四湖水、沉积物、动物中多环芳烃化合物的风险评价结果表明,南四湖水环境目前是安全的,但是值得注意的是,BaA, BaP, InP, DBA和BghiP在所有采样点中沉积物、水生植物和动物样品中都有检出,它们对南四湖生物存在着潜在致癌性。运用电感耦合等离子体-原子发射光谱法测定了南四湖水、沉积物、水生植物和动物中重金属砷、镉、铬、铜、铁、锰、镍、铅和锌的含量。水中检出的重金属含量都很低,而沉积物中重金属的含量相对水中重金属的含量较高,这说明南四湖水体中存在低含量、持续的重金属的输入。水生植物中铬和铁的含量超出其相应的毒性含量值。在水、沉积物、水生植物和动物中重金属含量相关性很低。因子分析和水、沉积物、水生植物和动物中不同重金属间相互关系分析结果表明：除了砷之外,其他大多数重金属间有相似的污染来源,同时也说明南四湖中砷的污染来源和其他重金属的污染来源不同。不同采样点上级湖和下级湖中重金属含量比较结果表明,上级湖中重金属的污染要比下级湖中重金属污染严重。南四湖丰富的煤炭资源是导致重金属污染的一个重要原因。生物积累因子分析结果表明,水生生物中砷和锌的积累和食物链营养级之间存在正向关系,除砷和锌之外的其他重金属并没有沿着食物链进行生物富集。南四湖水、沉积物、水生植物和动物中重金属的生态风险评价结果表明,南四湖水环境目前是安全的,但是要注意砷和锌的摄入。更多还原

【Abstract】 Nansi Lake is located in the southwest of Shandong province and is the largest freshwater lake in Shandong province, the northern area of China, which is an buffer lake of the South-to-North Water Diversion Project (east route). Nansi Lake consists of Nanyang Lake, Dushan Lake, Zhaoyang Lake and Weishan Lake. Nansi Lake is divided into the upper and lower lakes by a dam built in1960. The upper lakes, which include Nanyang Lake, Dushan Lake and Zhaoyang Lake, have more inflow rivers comparing with the lower lakes. After the water diversion project, the route of the water will be changed, the water will flow from the lower lake to the upper lake. Therefore, the water quality of Nansi Lake impacts the quality of the South-to-North Water Diversion Project (east route). In recent years, many research works have reported the residues of persistent organic pollutants (POPs), heavy metals, nutrient N, P in water and sediment of Nansi Lake. These studies showed that Nansi Lake is affected by the POPs, heavy metals, and nutrient N, P, but the pollutants level in water and sediment of Nansi Lake was relatively low, thus posing low level ecological risk. However, these researches mainly studied the pollutants in water and sediment of Nansi Lake, there is little information on the residual levels and ecological risks of POPs and heavy metals in food web of Nansi Lake. Nansi lake is the largest freshwater lake of the northern area of China and is rich in various aquatic organisms such as fish, shrimp and with large area of aquiculture. These aquaculture products had been sold to Chinese and abroad market. These organisms are the favorite foods for local people. Therefore, studying the level, bioaccumulation and risk assessment of POPs and heavy metals in food web provides reference data to further investigating the water pollution and ecological prospective of Nansi lake, and is important for human health. The aims of this research mainly include the following aspects:(1) to survey the levels and distributions of POPs (OCPs and PAHs) and heavy metals in various aquatic plants and animals in Nansi Lake,(2) toinvestigate the source of the POPs (OCPs and PAHs) and heavy metals in sediment,(3) to evaluate bioaccumulation of in aquatic biota samples in the lake by calculating the biota-sediment accumulation factor (BSAF) values,(4) to assess the POPs (OCPs and PAHs) and heavy metals effects on human health in Nansi Lake area.The concentration of12organochlorine pesticides (OCPs) were measured in water, sediment, aquatic plant and animal (shrimp and fish) of Nansi Lake by gas chromatography equipped with an electron capture detector (GC-ECD). The total OCPs concentrations were65.31-100.31ng L-1in water,2.9-6.91ng g-1dry weight (dw) in sediments,1.29-6.42ng g-1dw in aquatic plants and7.57-17.22ng g-1dw in animals. The OCPs composition profiles showed that heptachlor compounds was also the predominant OCPs contaminants in addition to hexachlorocyclohexanes (HCHs) and dichlorodiphenyltrichloroethanes (DDTs) in Nansi Lake. According to the source of HCHs and DDTs in sediment samples, there was no new input and the HCHs pollution mainly came from the use of Lindane in Nansi Lake. Bioaccumulation of OCPs in aquatic biota indicated that DDTs and heptachlor compounds had a strong accumulation, followed by HCHs and drins. The biota-sediment accumulation factor (BSAF) has been used to measure the biotic fate of the hydrophobic compounds in aquatic ecosystems. The BSAF is defined as the ratio of the concentrations in organism normalized by lipid content (LW) and the concentrations in the organic carbon of the sediments. P. crispus was one of the main aquatic plants in Nansi Lake and collected at all sampling sites. So, P. crispus, fish and shrimp were selected as representative aquatic organisms and studied the bioaccumulation of OCPs compounds. The BS AF values of fish were obviously higher than those of shrimp and aquatic plants. Aquatic plants are in a lower trophic level, compared to fish and shrimp. These results provided evidence of bioaccumulation of OCPs in food web. The accumulation abilities of fish for OCPs were higher than those of plant and shrimp. The OCPs biota-sediment accumulation factor (BSAF) values of Channa argus was the highest in fish samples, followed by Carassius auratus, Cyprinus caspio. This might be due to its habitat and feeding habits. C. argus is carnivorous animal and mainly prey on software animals, shrimp and small fishes, occasionally eat aquatic plants. C. auratu and C. carpio are omnivorous animals. Therefore, C. argus belongs to higher trophic levels compared to C. auratu, C. carpio and M. nipponense judging from feeding habits. The results also provide that bioaccumulation of OCPs exsit in food web.The mean concentration of HCHs and DDTs were22.15ng L-1and18.23ng L-1in water of Nansi Lake, respectively, which were far below the the surface water environment quality standard in China (GB3838-2002), which listed that the concentration of HCHs and DDTs was less than5000ng L-1and1000ng L-1, respectively, in surface water environment. The result shows that the water environment of Nansi Lake is safety. Two widely used sediment quality guidelines (SQGs) were applied to evaluate the possible ecotoxicological risk of OCPs in this study. One is the effects range-low value (ERL) and effects range-median value (ERM) guidelines (Long and MacDonald1995), the other is the threshold effects level (TEL) and probable effects level (PEL) guidelines. Result showed that a higher occurrence possibility of adverse ecological effects to benthic species is heptachlor epoxide, its levels were higher than TEL and PEL values in86%and14%of stations, respectively. Sediment environment of Nansi Lake is at low risk level, but pay more attention to heptachlor epoxide. Acceptable daily intake (ADI) and hazard ratio (HR) were applied to evaluate the possible ecotoxicological risk of OCPs in this study. Based on the calculation of acceptable daily intake (ADI) and hazard ratio (HR), HCHs in fish and shrimp from Nansi Lake had a lifetime cancer risk of greater than one per million. According to risk assessment results of water, sediment and fish, HCH and heptachlor epoxide had higher risk to human health compared to DDT "and drins.The concentrations of16polycyclic aromatic hydrocarbons (PAHs) were analyzed in water, sediment and biota (aquatic plant, shrimp and fish) of the Nansi Lake by gas chromatography-mass spectrometry (GC-MS). The concentrations of total PAHs were27.54-55.04ng/L in water,80.31-639.23ng/g dry weight (dw) in sediments,20.92-192.78ng/g dw in aquatic plants and67.3-533.9ng/g dw in fish and shrimp muscles. The ratios of phenanthrene to anthracene (Ph/An), fluoranthene to pyrene (Flu/Pyr) and low molecular weight to high molecular weight (LMW/HMW) in sediment indicated that the sources of the PAHs were a mixture of pyrolytic and petrogenic contamination at most sampling sites in Nansi Lake. The composition profile of PAHs in plants was similar to that in water and animals with2-3ring PAHs being dominant. The4-6rings PAHs were the dominant PAH compounds in sediment. There are positive correlations between sediment and aquatic plants, but their PAH composition profiles were different, implying that aquatic plant absorption of PAHs from sediment is selective, and the accumulation of PAHs in aquatic plants is different. The concentration of PAHs in fish showed positive correlation with plants, reflecting that the PAHs in fish are mainly absorbed from aquatic plants, rather than directly from the water besides water.The biota-sediment accumulation factor (BSAF) has been used to measure the biotic fate of PAH compounds in aquatic ecosystems. Bioaccumulation of LMW PAHs in aquatic biota was higher than HMW PAHs, suggesting that accumulation of the LMW PAHs compounds in aquatic plant, fish and shrimp samples is preferential compared to HMW PAHs compounds. The biota-sediment accumulation factor (BSAF) for total PAHs in the plants Potamogeton lucens Linn and Ceratophyllum demersum Linn were higher than those of most animals. The BAF values of total PAHs in animals were in the following order:Cyprinus caspio> Macrobrachium nipponense> Carassius auratus> Channa argus. C. argus is carnivorous animal and C. auratu and C. carpio are omnivorous animals, Therefore, C. argus belongs to higher trophic levels compared to C. auratu, C. carpio and M. nipponense judging from feeding habits. But the BAF values of total PAHs in C. argus were lowest among fishes and shrimp studied in this article. M. nipponense belongs to the lower trophic level compared to fish but the BAF value of total PAHs was1.3and was only lower than that of C. carpio. There was no significant relationship between PAH bioaccumulation and trophic levels in Nansi Lake. Risk assessment of PAHs in water, sediment and animals indicated that the water environment of Nansi Lake is safe at present. It is worthwhile to note that benzo[a]anthracene (BaA), benzo[a]pyrene (BaP), indeno[1,2,3-cd]pyrene (InP), dibenz[a,h]anthracene (DBA), benzo[ghi]perylene (BghiP) were detected in sediment, plants and animals at all sampling sites, and they have potential carcinogenicity to the organisms of Nansi Lake.The concentrations of heavy metals (As, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) were investigated in water, sediment and biota (aquatic plant, shrimp and fish) of Nansi Lake by an Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES). The concentrations of heavy metals in water were almost below detection limit, the concentrations of heavy metals in sediment were high compared to water, which indicated that there were low-level, persistent inputs of heavy metals in Nansi Lake. The concentrations of Cr and Fe exceeded the corresponding toxic concentrations in aquatic plants. The correlation among the concentrations of heavy metals in water, sediment, aquatic plants and animals is low. Factor analysis and the relationship of different heavy metals in water, sediment and aquatic biota samples showed that most heavy metals had the same source except As, which implied that As was of different source from the other heavy metals in Nansi Lake. The comparison of heavy metals in different samples from upper lake and lower lake showed that the contamination of heavy metals in upper lake was more serious than that in lower lake. The intensive coal mining is an important reason leading to contamination of heavy metals in Nansi Lake. The heavy metals in aquatic organisms were not accumulated along food web except As and Zn. There was a positive relationship between the accumulation of As and Zn and food web basing on bioaccumulation factors (BAF) value in Nansi Lake. Risk assessment of heavy metals in water, sediment and animals indicated that the water environment of Nansi Lake is safe at present. However, people should pay more attention to the intake of As and Zn.更多还原