【作者】 程凤鸣；

【导师】 李小明；

【作者基本信息】 山东大学 ， 环境工程， 2010， 博士

【摘要】 南四湖是山东省最大的淡水湖泊,同时也是我国华北地区最大的淡水湖泊,作为南水北调东线工程的重要输水通道和调蓄湖泊,在保障周边地区经济社会稳定发展和生态环境文明方面起着至关重要的作用。近年来,南四湖整个湖区水质已基本属于中度富营养化和富营养化水平,富营养化已成为南四湖面临的最重要的水环境问题之一。由于国家对南水北调沿线采用了严格的污染排放标准,有关部门采取综合防治措施,以确保在南水北调东线工程投入运行前,各入湖河流水质提前达到《地表水环境质量标准》(GB3838-2002)中Ⅲ类以上标准。但是,南四湖湖区作为一个庞大的、复杂的生态系统,其与外界物质、能量和信息的交流受多种影响因素。尤其是湖区水质污染受到特别的关注。在湖区水环境水质污染的影响因素中,除了通过河道流入湖区的污染水体外,还有湖区周边的面源污染、高空大气沉降和湖区内水生生物新陈代谢、湖底沉积物二次污染等。在这样的背景下,从不同学科出发,选择南四湖水环境中一个或几个具有代表性的问题进行研究,就显得具有重要的理论指导意义和现实社会应用价值。其中,由于湖泊沉积物在影响湖区水环境中的特殊作用和地位,越来越引起人们的关注。随着研究成果的不断丰富,对湖泊沉积物的形成过程、组成成份、形态特征及迁移运动规律有了更深的理解掌握。开展对湖区表层沉积物中的重金属和营养盐进行相关研究,可为调水前沉积物治理积累数据资料,为湖区开展流域污染综合治理提供科学依据。总体来说,受人类活动的影响,近二十年来南四湖水环境发生了很大的变化,并且这种变化的趋势还在进一步加剧,特别是像南四湖二级大坝和南水北调东线这种改变自然生态景观的人为工程的建设,对南四湖现代水环境的影响更是难以估量的。基于以上考虑,本文对南四湖水环境污染特征及其重金属离子去除机理进行了相关研究,主要结论如下：1、南四湖沉积物中营养盐的含量及分布湖泊柱状沉积物中保存有湖区环境变化的丰富信息,营养盐含量的变化是湖泊富营养化渐进过程的标志。同一水体不同深度的底泥中积累的氮、磷物质也就记录着人为活动和自然变化对湖泊环境的影响。因此建立与恢复柱状沉积物中的营养盐含量的变化序列,对于研究湖泊环境污染历史具有重要的理论意义,并且可为现代湖泊环境的整治工程提供科学依据。(1)磷的含量及重直分布。对分别取自南阳湖和昭阳湖湖区的两个柱状沉积物进行分析,柱状沉积物中总磷含量的统计值表明,不同地点所采集的柱状岩芯中总磷的含量差别较大,南阳湖Core—1岩芯的平均值高达787 mg/kg,昭阳湖Core—2岩芯的平均值仅为590 mg／kg。由最小值和最大值的差距来看,Core—1号岩芯的最小值为512mg／kg,最大值为1374mg／kg,两者之间的差距超过2.5倍,Core—2岩芯的最小值为520mg／kg,最大值为768mg／kg,差距低于1.5倍。两个岩柱沉积物在总磷含量垂直变化上,分布曲线体现出从岩芯底部向顶部逐渐升高的趋势。南阳湖和昭阳湖在岩芯的底部磷含量基本都是处于500-550mg／kg左右的含量,南阳湖沉积物中磷含量上升较快,昭阳湖磷含量从底部向上部也呈现逐渐上升趋势,但在底部和中段表现不是非常明显,没有南阳湖上升幅度大。总体来看,昭阳湖岩芯中磷含量,对应深度上低于南阳湖。这可能与磷的来源、湖泊湖流运动规律或湖泊沉积环境有关系。(2)总氮、总有机碳、总碳含量及分布。南四湖不同地点沉积物中总氮、总有机碳和总碳含量存在差异。南阳湖柱状沉积物中总氮最大值为6056mg／kg,为最小值的近10倍,平均值为2240 mg／kg；总有机碳最大值为5.61%,为最小值的10倍多,平均值为2.21%；总碳最大值为7.56%,最小值为1.48%。昭阳湖柱状沉积物中总氮最大值为11228mg/k,为最小值的10倍多,平均值为5707mg／kg；总有机碳最大值为9.62%,为最小值的12倍多,平均值为5.35%；总碳最大值为12.37%,最小值为6.66%。由数据分析看出,不同地点所采集的柱状岩芯中总氮、总有机碳、总碳的含量差别较大。昭阳湖岩芯中总氮的平均值约为南阳湖总氮平均值的2.5倍；南阳湖岩芯中有机碳的平均值为2.21%,而昭阳湖岩芯的平均值则高达5.35%,由最小值和最大值的差距来看,昭阳湖岩芯总碳、总有机碳、总氮含量的最小值、最大值都普遍比南阳湖里的大。在垂直变化上,两个柱状岩芯中总碳、总有机碳、总氮含量的变化。可以看出曲线的变化趋势与总磷的变化趋势相似,曲线变化也呈现出有底部到顶部逐渐上升的趋势。通过对南四湖上级湖表层沉积物与柱状沉积物分析结果,可以得出以下结论：济宁市及其他市县的城市生活污水、农业退水和工业废水排放进入南阳湖是南四湖有机质和TP污染的主要来源；柱状沉积物中营养元素具有较稳定的垂直分布,并具有明显的由底部向顶部逐渐上升分布特征,反映了流域社会经济的发展导致营养元素的释放量增加,造成了湖泊现代沉积物中营养元素的积累。2.南四湖沉积物重金属含量和形态组成研究对南四湖重金属元素形态组成分析上,利用的是本课题组2005年9月在南四湖主要入湖河流及湖区采集的28个表层(0～10cm)沉积物样品。采集时对样品现场进行pH、Eh测定,样品装入密封袋中低温运回实验室,冷冻干燥后进行沉积物粒度组成、重金属元素形态、TOC含量等分析。分析表明,丰水季节,南四湖流域泗河、京杭运河、洙赵新河、洗府河上游、上级湖南部湖区及下级湖区表层沉积物中重金属人为污染程度较弱,重金属元素形态组成主要反映了其自然属性,Cr, Cu、Ni、Zn以残渣态为主,Pb、Mn主要赋存于残渣态和可氧化态。老运河、洗府河入湖口、白马河表层沉积物中Cr、Cu、Ni、Zn的可氧化态、酸提取态、可还原态含量明显增加,其次生相富集系数最高达10.5,明显受到人为污染,污染源主要是济宁市及白马河上游地区；随着表层沉积物中有机质的矿化分解及环境条件的改变,这些水体沉积物中Cr、Ni、Cu、Zn等重金属元素可发生形态转化,具有较高的潜在生态风险。对于南四湖沉积物重金属含量的空间分布,本文在两个方面进行了研究。是沉积物含量垂直分布上,按照湖泊沉积物地球化学样品采集工作方法要求,利用重力采样器在南阳湖和昭阳湖各采集了一个长0.37m的柱状沉积岩芯,标号分别为core-1、core-2。对每个岩柱前面15cm每0.5cm取样,后面每1.0cm取样。每样品各取样52个,分别登记编号。样品分析项目包括：总氮(TN)、总有机碳(Org-C)、总磷(TP)、金属元素(汞、砷、铅、铜、镍、锌等)、210Pb等。重金属元素等由中国地质科学院地球化学研究所实验室测试,测试过程严格按照生态地球化学评价样品分析技术要求进行。本研究采用的是210Pb纪年模式中的第一种计算模式,即CIC模式,计算出结果如下：南阳湖平均沉积速率为0.35cm／a,昭阳湖平均沉积速率为0.26cm／a。该研究结果与其他学者的研究结论基本吻合。在垂直方向上,汞的含量是较高的,富集系数达到12.5。二是重金属含量水平分布上。利用抓式取样器,分别在南四湖上级湖、下级湖和主要入湖河流河口区三个湖区单元,采集了40个沉积物样品,通过利用地积累指数和潜在生态风险指数两种指标相结合的方法,利用在室内化验分析取得的测试结果进行综合评价。结果表明,Cd是湖区主要污染元素,As污染次之,其它金属元素均属于较轻的污染程度。主要入湖河流河口区和上级湖区处于很强生态危害污染状态,下级湖处于轻微生态危害状态。因此,在南四湖水环境的治理保护当中,对重金属Cd和Hg的富集及其生态效应问题应引起高度重视。3.南四湖富营养化评价与原因分析济宁市及周边地区工农业和旅游业的迅猛发展发展,产生的大量污染物被排入南四湖,使其水质急剧恶化,出现富营养化现象。南四湖水质的恶化,不仅制约着济宁市社会经济的发展,还影响着数百万人民群众的生活质量的提高和在南水北调工程中所起的作用。通过选取了与水体富营养化关系密切的叶绿素a(Chla).总磷(TP)、总氮(TN)、透明度(SD)和高锰酸盐指数(CODMn)五项代表性的检测指标作为调查项目,采用综合营养状态指数(TLI)作为评价方法,对南四湖2008年8月份的62个水质样品进行计算。根据计算数值,采用0-100的一系列连续数字对南四湖营养状态进行分级。结果表明,四个湖区中南阳湖的叶绿素a、总磷、总氮和高锰酸盐指数的含量最高,分别为0.056 mg／m3、0.43 mg／L、3.38 mg／L和7.3 mg／L；微山湖中含叶绿素a、总磷和高锰酸盐指数的含量最低,分别为0.01 mg/m3、0.03 mg／L和5.16 mg／L；昭阳湖中的总氮含量最低为1.62mg／L。而透明度的值却与叶绿素a、总磷、总氮和高锰酸盐指数的值变化趋势正好相反,南阳湖的透明度只有0.47 m,昭阳湖最高达到0.72 m,微山湖为0.63 m。通过综合营养状态指数法,南四湖四个湖区的污染程度由重到轻分别是：南阳湖、独山湖、微山湖和昭阳湖。南四湖出现富营养化并不是偶然的,既有天然因素又有人为因素。湖区水体浅、流速慢、循环周期长为南四湖发生富营养化提供了自然条件；人类活动所产生的大量工业废水、生活污水和现代农业过量使用化肥、农药形成面源污染等进入南四湖,是南四湖营养盐迅速增加,导致水体富营养化的人为因素。4.南四湖重金属离子去除机理研究研究结果表明,重金属污染已成为亟待解决的南四湖水环境水环境问题之一。除了工程措施外,选择合适材料开展对南四湖水环境中重金属污染去除的研究也很有意义。为控讨重金属离子去除去除机理,本文利用密度泛函理论[Density functional theory (DFT)],在两个方面进行了研究。一是壳聚糖吸附Hg2+,pb2+和Ag+离子的机理研究。壳聚糖是一类重要的天然类多糖衍生物,在废水处理、贵金属富集和生态修复方面发挥着重要。各种金属离子的电子结构不同,通过对壳聚糖进行化学修饰,人们可以改变所形成的吸附复合物的稳定性,以便进行选择性吸附和工业操作,但由于目前实验手段的限制,实验上确定金属离子与壳聚糖的相互作用本质还存在较大的困难,而现代量子化学方法为人们探索这种作用机理提供了一种强有力的工具。计算结果表明,过渡金属离子Hg2+,Pb2+和Ag+主要吸附在壳聚糖中的氨基氮原子和羟基氧原子之间,并与壳聚糖主链上的氧原子存在较强的相互作用,Hg2+和Pb2+离子的结合能比Ag+的结合能大得多；Hg2+,Pb2+和Ag+等重金属离子与壳聚糖的相互作用主要为静电相互作用。二是硅表面吸附铜原子和水合铜离子的研究。研究结果表明,铜离子与Si(111)表面的相互作用主要包括部分的共价键作用和静电作用；在Si(111)表面水合铜离子的配位数为4,当水分子数目大于5时,水分子之间形成分子间氢键；在水溶液中,水合铜离子可以稳定的吸附在Si(111)表面。更多还原

【Abstract】 Nansi Lake in Shandong Province is the largest freshwater lake, but also the largest freshwater lake in northern China. Nansi Lake as an important water channels and flood storage lakes in the south-east-line project, plays a vital role in protection of economic, social stability, development in surrounding areas and ecological civilization. In recent years, eutrophication has become one of the most important water environmental issues of Nansi Lake. Since the state adopted strict standards for pollutant discharge, relevant departments will take corresponding integrated prevention and measures to ensure that the river water into the lake ahead of schedule to achieve criteria Class III ("Surface Water Environment Quality Standard")(GB3838-2002), before the south-east-line project putted into operation. However, Nansi Lake as a large and complex ecosystem, its material, energy and information exchange to the outside are constrained by many factors. In addition to polluted waters through the river into the lake, as well as the non-point pollution, high-altitude air settlement, aquatic metabolism in the lake district and the secondary pollutants of lake bottom sediments are all the factors of the ambient water quality. Under this background, this paper studied one or several aspects of the water environment in Nansi Lake from different disciplines. The study is of great significance in theory and practice. As lake sediments play an important and key role in affecting the lake water environment, they are attracting more and more attention. As the research is incessantly deepened, We now have a better understanding of formation, constituent, characteristic, migration regularity and motion law of lake bottom sediments. Heavy metals in the surface sediments and nutrient salts in the lake district were studied, which can accumulate valuable data for sediment before water transfer and can offer scientific evidence and technique guide for prevention and control of the pollution in major river valleys. Overall, with the impact of increasing the intensity of human activities, water environment in Nansi Lake has already undergone great changes in the past 20 years and this trend is further exacerbated. The engineering construction project, especially the secondery dam of Nansi Lake and the east line of the south to north water project, can change natural landscape. The environmental repercussions are inestimable. Owing to the above factors, an extensive research of water environment in Nansi Lake was conducted. The main conclusions are:1.Content and distribution of nutrient salts in Nansi Lake.The core sediments in lake record more information of environmental changes and the change of nutrient salts content is an important symbol of gradual process of the eutrophication in lakes. N and P accumulated in different depth water sediments record the effect of human activities and nature change on the lake environment. Therefore, establishing and recovering of sequence transformation of the content of nitrogen have an important theoretical meaning for researching the pollution history and can offer scientific evidence for regulation project of lake environment.(1) The content of P in horizontal directionOn the basis of analyseis of the two core sediments collected from Nangyang Lake and Zhaoyang Lake, we concluded that the content of total phosphorus in the cylindrical core from different locations has great difference. The average contents of core-1 and core-2 were 787mg/kg and 590mg/kg respectly. The maximum value of core-1 was 1374mg/kg and the minimum was 512mg/kg, and the maximum value was two times than minimum value. The maximum value of core-2 was 768mg/kg and the minimum was 520mg/kg, and the maximum value was 1.5 times than minimum value.The distribution curve of the content of P in horizontal direction in the two core sediments reflects a trend of a gradual increase from the core at the bottom to the top. The contents of phosphorus in the bottom of the core in Nangyang Lake and Zhaoyang Lake were both about 500-550mg/kg. The content of phosphorus in Nanyang lake sediments increased rapidly, and the phosphorus content from the bottom to top in Zhaoyang Lake also showed a gradual upward trend, but at the bottom and the middle of the performance were not very clear.Overall, the corresponding depth of the phosphorus content of the core in Zhaoyang Lake is below the Nanyang Lake. This may have a close relation to the source of phosphorus and the lake motion law. (2)The content and distribute of total organic carbon and total organic nitrogenous:The different areas of Nansi Lake have different contents of total organic carbon and total organic nitrogenous. The maximum of the total nitrogenous of the sediments in Nanyang Lake was 6056mg/kg about ten times higher than the minimum and the average value was 2240mg/kg. The maximum of the organic carbon of the sediments in Nanyang Lake was 5.61% about ten times higher than the minimum and the average value was 2.21%. The maximum of total carbon in Nanyang Lake was 7.56% and the minimum was 1.48%. The maximum of the total nitrogenous of the sediments in Zhaoyang Lake was 11228mg/kg about ten times higher than the minimum and the average value was 5707 mg/kg. The maximum of the organic carbon of the sediments in the lake was 9.62% about twelve times higher than the minimum and the average value was 5.35%. The maximum of total carbon was 12.37% and the minimum was 6.66%. From the data analysis we can see that there is a world of difference among the different locations of the cylindrical cores collected in the total nitrogen, total organic carbon, and total carbon content. The average of total nitrogen in Zhaoyang Lake core is about 2.5 times than the average total nitrogen in Nanyang Lake. The average organic carbon of the core of Nanyang lake was 2.21%, while the average of the core of Zhaoyang Lake was as high as 5.35%. Across the gap between the minimum and maximum terms, the total carbon, organic carbon and the total nitrogen contents of the minimum and maximum of the core of Zhaoyang Lake, were generally higher than Nanyang Lake. Changes in the vertical, the two cylindrical core of total carbon, total organic carbon, total nitrogen content changes. Changes can be seen that the curve trends are similar to the trends in total phosphorus curve, which is also shown a gradual upward trend from the bottom to the top.Through analyzing the surface and the core sediments in the upper lakes of Nansi Lake, we have come to the conclution:Dmestic wastewater, aricultural wastewater and idustrial wstewater discharged to Nanyang Lake were the main sources of pollution in Nansi Lake. Nutrient elements in sdiments had a stable Vertical distribution and had a clear gradual increase from the bottom to the top, which reflected that the local socio-economic development led to the increasing emissions of nutrients and the accumulation of nutrients in the modern lake sediments.2.The contents and morphology of heavy metals in the sediments of Nansi Lake.In this paper, spatial distribution characteristics of heavy metals in the sediments of Nansi Lake were studied from horizontal and perpendicular distributions two aspects. One Study is the contents and morphology of heavy metals in Horizontal Direction. Forty sediment samples from the lower and upper of Nansi Lake and its main inflow rivers were collected by grabing sampler in three lots. The potential ecological risk index (RI) and geological acumination index (Igeo), as the quantitative diagnostic tools, are used to evaluate the results of chemical analyses. The result showed:the main pollution element in the particles was Cd. And As was the secondary pollution element and the pollutions by other metallic element were slight. The potential ecological risk was quite strong at the upper lake and the estuary, and the ecological risk of the lower lake was very light. Another study is the contents of the sediments in the vertical distributions. According to the requirement of geochemical lake sediment survey, two columnar sediment core with a depth of 0.37m were collected by gravity sampler in Nanyang Lake and Zhaoyang Lake, labeled core-1 and core-2. We take a sample every 0.5 cm in front of 15 cm of each sample pillar and every 1 cm in the back.52 samples registered and numbered were taken from each sample pillar. Analysis of samples includes Org-C, TN, TP,210Pb and heavy metals (including Hg As Pb Cu Ni Zn). Heavy metals were tested in the Institute of Geophysical and Geochemical Exploration (IGGE) of the Chinese Academy of Geological Sciences (CAGS) and the procedure of the research test strictly met the standards of ecogeochemical evaluation method. The conclusions are as follows:(1) The average deposition rate in Nanyang Lake was 0.35cm/a and 0.26cm/a in Zhaoyang Lake. The above mentioned results are almost in agreement with the results of other scholars’studies. On the vertical directation, Hg content was high and the accumulation coefficient reached 12.5. Therefore, it is worthwhile to pay more attention to the concentration of Cu, Hg, and its ecological effect during the process of water environmental treatment and protection in Nansi Lake. Analysis of the speciation of heavy metals are based on 28 surface sediment samples (0-1 cm) collected by this research group in Nansi Lake and its main inflow rivers in September 2005. pH and Eh were measured at the scene and samples placed in sealable bags were transported into laboratory at a low temperature. Then freeze dried, afterward the samples were analyzed for the sediment, the speciation of heavy metals and the content of TOC. The analysis shows:heavy metal artificial pollution in the surface sediments of Nansi Lake and its main inflow rivers-Si River, Jinghang Great Canal, Zhuzhao River, the upper reaches of Guangfu River and the upper south lake and the lower lake was fairly light. The morphology and composition of heavy metal mainly reflect its nature. Cr, Cu, Ni, Zn mainly existedin residual fraction; and Pb and Mn mainly existed in residual fraction and oxidizable fraction. Residual fraction and oxidizable fraction of Cr, Cu, Ni and Zn in the surface sediments of the former canal, lake inlet of the Guangfu river and Baima river increased obviously. The bioconcentration coefficient was high to 10.5. These are important signals for artificial pollution.The most pollution sources were the upper reaches of the Baima river and the city of Jining. As organic matter in the surface sediments decomposes and environmental changes, these heavy metals in water can transform, which has a highly potential ecological risks.3、Analysis and assessment on eutrophication of Nansi lake.With the fast development of agriculture, industry and tourism in Jining and its surrounding areas, enormous quantities of pollutants have been discharged into the Nansi Lake. Now the water quality is rapidly deteriorated and eutrophication is happening. The water deterioration of Nansi Lake limits not only the development of jining society and economy in Jining but also the improvement of millions of citizens’life quality and the function in south-to-north water transfer project. The five typical tests (Chl-a, TP, TN. SD and CODmMn) which have close relation with the eutrophication are monitored with integrated nutrition state index (TLI). According to the calculating data of sample, using the number from 0 to 100 to grade the entrophication state of Nansi Lake. The results indicate that Chl-a, TP, TN and CODMn in Nanyang Lake were all the highest in the four lake areas and were 0.056mg/m3,0.43mg/L,3.38mg/ and 7.3mg/L respectively. Chl-a, TP and CODMn in Weishan Lake were the lowest and were 0.01mg/m3,0.03mg/1,5.16mg/l respectively. The lowest TN in Chaoyang Lake is 1.62mg/1. The trend of transparency is negatively related with the change in Chl-a TP, TN, SD and CODMn. The transparency of Nansi Lake was only 0.47m, the transparency of Chaoyang Lake was as high as 0.72m and the transparency of Weishan Lake was 0.63m. Through the index of entrophication of four lakes in Nansi Lake, the order of the pollution for serious level to light level in the four key river systems is:Nanyang Lake, Dushan Lake, Weishan Lake and Zhaoyang Lake.The major causes of the entrophication of Nansi Lake are not only natural factors but also factitious factors. Low water level, slow rate and long cycle provide the entrophication of Nansi Lake with natural conditions. Human activities make enormous quantities of industrial waste water and domestic sewage and in modern agriculture, overuse of chemical fertilizers and pesticides causes an non-point pollution, which makes the nutrient salts sharply increasing in Nansi Lake. All of these lead to the eutrophication of water bodies.4、Research of the mechanism of adsorbing heavy metal ions onto chitosan and clean Si. Chitosan is an important class of natural polysaccharides derivatives, which plays an important in wastewater treatment, precious metal enrichment, removal of heavy metals in lake sediments and ecological restoration. Because of its repeating unit with the active groups (such as amino, hydroxyl), Chitosan can react with a variety of metal ions such as Hg2+, Cd2+, Cu2+, Ni2+ and Zn2+, then forming a more stable chelate. Since the electronic structures of various metal ions are different, the stability of complexes formed has a big difference. By chemical modification of chitosan, we can change the stability of chelate formed for selective adsorption and industrial operations. In the past few decades, a series of studies of Chitosan adsorbing metal ions have been done in different environments. It is generally believed that the mechanism of Chitosan adsorbing metal ions would be chelate mechanism and electrostatic attraction mechanism. In neutral solution, the interaction between Chitosan and heavy metals is chelate mechanism. However, great difficulties have been encountered to determine the interaction mechanism between metal ions and the chitosan because of the restrictions of experimental methods. While the Quantum Chemical Method to research of the mechanism has become a powerful tool.To find out the nature of interaction between heavy metal ions and chitosan and to provide the theoretical basis for the removal of heavy metals in lake sediments, the density functional theory (DFT) was first introduced in to study the interaction betwwen ions (Hg2+, Pb2+ and Ag+) and chitosan and calculate the chitosan adsorption energy. The results show that transition metal ions (Hg2+, Pb2+ and Ag+) are mainly adsorbed on the amino nitrogen atoms and hydroxyl oxygen atoms of the chitosan, and have strong interaction with oxygen atoms in the chitosan main chain. The binding energy of Hg2+ and Pb2+ ions is much greater than Ag+. The interaction mechanism between Hg2+, Pb2+ and Ag+ and other heavy metal ions and chitosan is mainly electrostatic interactions.更多还原