【作者】 于靖；

【导师】 刘兴荣； 陶玉强；

【作者基本信息】 兰州大学 ， 预防医学·劳动卫生与环境卫生学， 2017， 硕士

【摘要】 多环芳烃（Polycyclic Aromatic Hydrocarbons,PAHs）是一类分子中含有两个或两个以上苯环结构的烃类化合物,主要来自煤、石油、生物质及垃圾焚烧等人类活动。其在环境中广泛且持久存在,可以被生物富集并在食物链中传递,多数具有致癌、致畸、致突变等危害。掌握其在水环境中的分布和归趋对保障供水及生态系统安全具有重要意义。研究目的:以长江下游亚热带地区不同水深不同营养水平的4个湖泊（太湖、玄武湖、金牛湖及百家湖）为例,通过对各湖一周年同步高频次野外监测,探讨多环芳烃在湖泊浮游生物网中的富集与传递及其主要影响因素;揭示多环芳烃在不同类型湖泊水体、悬浮颗粒物、浮游植物及浮游动物等介质中的周年分布规律;探讨气候因素（温度、降水）对多环芳烃分布的影响及其规律。补充对亚热带浅水湖泊中多环芳烃的赋存及主要生物地球化学过程的认识。研究方法:以长江下游亚热带地区不同营养水平的4个湖泊为例,在2015年10月至2016年9月间同步开展高频次的样品采集,定量监测多环芳烃在各湖水体、浮游植物、浮游动物和悬浮物中的浓度,收集相关的气象资料,结合统计分析方法探讨可能的影响因素。具体方法如下:（1）每月月中及月末采样各1次,分别收集水、浮游植物、悬浮物和浮游动物,冷冻干燥并称重以计算生物量等指标;（2）检测样品中的溶解态营养盐,利用TSI-TLI指标评价金牛湖、百家湖、玄武湖和太湖的富营养化程度;（3）检测各介质中的多环芳烃浓度,计算浮游植物和浮游动物的生物富集因子和生物累计因子,计算生物传递因子。研究结果:（1）所研究的湖泊均处于富营养化或中营养化向富营养化过渡阶段;（2）2016年6月及7月降水是他年同期均值的2倍,异常气候可能对研究造成了影响;（3）湖泊中浮游植物生物量年均值分别为金牛湖7.24±5.63 mg?L^-1,百家湖12.72±5.51 mg?L^-1,玄武湖30.35±14.90 mg?L^-1,太湖40.85±31.02 mg?L^-1;浮游动物生物量年均值分别为百家湖88.09±58.25μg?L^-1,金牛湖54.15±58.28μg?L^-1,太湖184.72±155.22μg?L^-1,玄武湖78.80±54.93μg?L^-1;悬浮物浓度年均值分别为百家湖4.67±3.31 mg?L^-1,金牛湖2.05±1.81 mg?L^-1,太湖13.82±22.24mg?L^-1,玄武湖5.11±2.86 mg?L^-1;（4）金牛湖水中16种多环芳烃总含量（∑PAHs）周年变化范围为20.2 ng?L^-1-648.1 ng?L^-1,百家湖水体中多环芳烃总含量周年变化范围为34.5 ng?L^-1-416.4 ng?L^-1,玄武湖水体中多环芳烃总含量周年变化范围为52.2 ng?L^-1-663.0 ng?L^-1,太湖水体中多环芳烃总含量周年变化范围为37.3 ng?L^-1到1365.7 ng?L^-1,各湖泊的水体中萘及自由溶解态的萘含量均高;（5）浮游植物16种多环芳烃总浓度周年变化范围分别为金牛湖5355.8 ng?g^-1-195070.6 ng?g^-1,百家湖2168.1 ng?g^-1-38326.9 ng?g^-1,玄武湖296.6 ng?g^-1-46716.0 ng?g^-1,太湖为559.7 ng?g^-1-26202.3 ng?g^-1,各湖泊浮游植物内多环芳烃中萘占有较高比例;（6）浮游动物内16种多环芳烃总浓度周年变化范围分别为金牛湖3115.7 ng?g^-1-372881.4 ng?g^-1,百家湖1169.0 ng?g^-1-82887.1 ng?g^-1,玄武湖687.3 ng?g^-1-124541.4ng?g^-1,太湖为592.7 ng?g^-1-43806.4 ng?g^-1;（7）4个湖泊16种多环芳烃的生物富集因子（BCF）的对数值（log BCF）周年变化范围为2.7-7.7,生物累积因子（BAF）的对数值（log BAF）变化周年变动范围为2.1-8.3,4个湖泊生物传递因子（BMF）的对数值（log BMF）均存在小于0的情况;（8）经多元线性回归,4个湖泊浮游植物生物量受温度驱动（P<0.05）,并同溶解性硝酸盐呈显著负相关（P<0.05）,玄武湖和百家湖的浮游动物生物量与温度之间的关系出现异常而呈现了显著负相关关系（P<0.05）;（9）4个湖泊浮游植物和浮游动物体内多数多环芳烃的浓度与生物量呈现显著负相关关系（P<0.05）,部分（低环）多环芳烃生物富集因子同生物量呈现显著负相关关系（P<0.05）,多数多环芳烃生物累积因子同生物量呈现显著负相关关系（P<0.05）;（10）4个湖泊中部分多环芳烃的生物富集因子和生物累积因子与温度呈现显著的二阶段函数关系（P<0.05）。结论:研究的四个长江下游湖泊多环芳烃污染情况不容乐观;年时间尺度下湖泊中的浮游生物生物量受温度驱动;浮游生物体内多环芳烃浓度与生物量呈显著负相关,受生物稀释效应影响;前期在玄武湖观查到的生物富集因子与温度之间的二阶段函数关系适用于其它长江下游亚热带富营养化浅水湖泊。更多还原

【Abstract】 Objectives: Polycyclic aromatic hydrocarbons（PAHs）are typical of persistent organic pollutants（POPs）,with a molecule contains two or more benzene ring structure hydrocarbons but any impurity atoms and substituents.For its carcinogenicity,teratogenicity,mutagenicity,capabilities of Long Range Atmospheric Transport（LRAT）and the high rate of bioaccumulation,PAHs are distributed in colossal amounts of environmental factors through human activities.The study on PAHs accumulated in the water environment is of significance and practice.A research was conducted in 4 lakes which in the Lower Yangtze River BasinClimates,depth,nutrition were concerned.Explore the Factors on accumulation,distribution,fate and transport of PAHs in subtropical shallow lake planktonic food webs;Methods: Lake Jinniu,Lake Baijia,Lake Xuanwu and Lake Taihu were observed among lakes in the Yangtze River Basin.Sampling campaigns were carried out twice or three times a month.Once in the middle quantum and the other in late quantum of each month during a 12-month period from Octuber,2015 to September,2016.Water,phytoplankton,zooplankton and total suspended particles（TSP）were collected in every period.0.7um GF/F glass fiber filters were used for collecting phytoplankton,zooplankton and TSP.250 ml pre-filtered water samples were concentrated with C18 solid phase extraction columns.100 ml water was filtered with GF/F glass fiber filter for dissolved nutrient and dissolved organic carbon（DOC）analysis in every campaign.The pH and concentration of Chl a analyses also were conducted with enough volume water in the research.104 Samples were chemical analyed with GC-MS（Agilent 1890B-5977A）.Results:（1）The lakes studied were in eutrophication or evaluating to Eutrophication measuring with TSI-TLI index;（2）The precipitation in June and July 2016 was two times as the average of the other year in the same period during summer,and Anomaly features of summer precipitation might have effected the research results.（3）The annual averages of phytoplankton biomass in 4 lakes were 7.24±5.63 mg?L^-1（Lake Jinniu）,12.72±5.51 mg?L^-1（Lake Baijia）,30.35±14.90 mg?L^-1（Lake Xuanwu）,40.85±31.02 mg?L^-1（Lake Taihu）respectively;The annual averages of zooplankton biomass in 4 lakes were 54.15±58.28 μg?L^-1（Lake Jinniu）,88.09±58.25 μg?L^-1（Lake Baijia）,78.80±54.93 μg?L^-1（Lake Xuanwu）,184.72±155.22 μg?L^-1 mg?L^-1（Lake Taihu）respectively;The annual average concentration of TSP in 4 lakes were2.05±1.81 mg?L^-1（Lake Jinniu）,4.67±3.31 mg?L^-1（Lake Baijia）,5.11±2.86 mg?L^-1（Lake Xuanwu）,13.82±22.24 mg?L^-1 mg?L^-1（Lake Taihu）respectively.（4）In water,the total concentrations of 16 PAHs ranging from 20.2 ng?L^-1 to 648.1 ng?L^-1（Lake Jinniu）,from 34.5 ng?L^-1 to 416.4 ng?L^-1（Lake Baijia）,from 52.2 ng?L^-1 to 663.0 ng?L^-1（Lake Xuanwu）,from 37.3 ng?L^-1 to 1365.7 ng?L^-1（Lake Taihu）during 12 months respectively.（5）Concentration of total 16 PAHs in Phytoplankton annual variation ranging from 5355.8 ng?g^-1 to 195070.6 ng?g^-1（Lake Jinniu）,from 296.6 ng?g^-1 to 46716.0 ng?g^-1（Lake xuanwu）,from 2168.1 ng?g^-1 to 38326.9 ng?g^-1（Lake Baijia）,from 559.7 ng?g^-1 to 26202.3 ng?g^-1（Lake Taihu）respectively.（6）Concentration of total 16 PAHs in zooplankton annual variation ranging from 3115.7ng?g^-1 to 372881.4 ng?g^-1（Lake Jinniu）,from 687.3 ng?g^-1 to 124541.4 ng?g^-1（Lake xuanwu）,from 1169.0 ng?g^-1 to 82887.1 ng?g^-1（Lake Baijia）,from 592.7 ng?g^-1 to 43806.4 ng?g^-1（Lake Taihu）respectively.（7）Numerical values of 16 PAHs bioconcentration factors（BCF）in 4 lakes ranging from 2.7 to 7.7 annually.Bioaccumulation factors’（BAF）numerical values（log BAF）change annually in the range of 2.1 to 8.3,and there are certain biological magnification factors’（BMF）numerical values（log BMF）less than 0;（8）Stepwise multiple linear regression was used to identify dominant driving factors for phytoplankton biomass,4 lakes phytoplankton biomass driven by temperature（P<0.05）,and significantly negative correlations were founded among phytoplankton biomass and dissolved NO3-（P<0.05）.Unconventionally,significant negative correlations were exposed between zooplankton biomass and temperature in lake Xuanwu and Lake Baijia（P<0.05）;（9）Significantly negative correlations between concentration of polycyclic aromatic hydrocarbons and biomass were observed in phytoplankton and zooplankton（P<0.05）.Negative correlations were revealed among bioconcentration factors and biomass（P<0.05）,and significant negative correlations were showed in most kinds of PAHs among bioaccumulation factors and biomass（P< 0.05）.（10）Significantly quadratic term relationship were exposed when comparing BCFs orBAFs with temperature（P<0.05）.Conclusions: The pollution condition of PAHs in the 4 lakes is not optimistic.The plankton biomass in the typical shallow eutrophic lake is usually dictated by temperature.The concentrations of PAHs in the plankton are negatively correlated with biomass,under biological dilution affection on them.The subsequent relationships between PAHs and the temperature are not only applicable to the Lake Xuanwu,but also to the subtropical shallow eutrophic lakes in the lower reaches of the Yangtze River,distincting from the linear model of proven biological activity of hydrophobic contaminants.更多还原