【作者】 郝云超；

【导师】 翟世奎；

【作者基本信息】 中国海洋大学 ， 海洋地质， 2008， 博士

【摘要】 长江和黄河每年向中国东部边缘海输送包括污染物在内大量物质，东亚沙尘也是向太平洋输送各种物质的重要途径；中国东部边缘海的济州岛西南泥质区，闽浙沿岸泥质区，南黄海泥质区，北黄海泥质区和渤海泥质区等是进入海洋的细颗粒物质的沉积中心。本论文首先阐述了胶体絮凝机制，将其应用海洋中细颗粒泥质区的成因探讨。中国边缘海的泥质区都是处在物理化学条件（例温度和盐度等）经常发生规律性变化的上升流区，物理化学条件的变化致使水体中的胶体组分发生絮凝沉降，从而形成海底的细颗粒泥质沉积。利用ICP-AES对渤海和北黄海118个表层沉积物和渤海湾柱状样B18的0-40cm的57个样品的主量元素含量进行了测试，用ICP-MS测试上述样品微量（包括稀土元素）元素的含量，同时利用激光粒度仪测试上述样品的粒度组成。对渤海湾东西分布的三根沉积物柱状样A435，B18和B178进行了。²¹⁰Pb测年。通过分析渤海和北黄海118个表层沉积物的有毒元素含量分布，发现渤海的有毒元素主要来源于河流的输入，大连工业区是北黄海西部的重要污染源。有毒元素的分布反映了沉积物从海岸到近海的输送趋势。因为溶解元素明显受颗粒物的吸附和絮凝沉淀作用影响，而颗粒物在咸水和淡水界面具有明显的絮凝沉积作用，所以黄河口地区具有高的有毒元素含量。通过对有毒元素的富集系数，以及和Fe含量相关性的研究，表明和其它有毒元素相比，人为源对As和Sb的贡献比例可能更大。PCA的研究结果表明自然源仍然是测试元素的主要来源，渤海湾是渤海四个亚分区中污染最严重。将渤海和北黄海西部表层沉积物的有毒元素含量和中国、美国海洋沉积物质量标准进行了比较，并且利用地累积指数NIgeo和Hakanson评价方法对渤海和北黄海西部的表层沉积物样品进行了生态环境风险评价。As和Cd具有相对高的Ers值，表明As和Cd是导致研究区域具有较高的生态风险的两个主要元素。渤海湾，黄河口和辽东湾的西南部可能均处在中等生态风险中。北黄海西部大连附近海域受大连工业区排污的影响，有毒元素污染相对严重，其中As的污染最严重，此区总体处于中-中高等的生态风险。北黄海中部泥质区的有毒元素具有较高的含量，具有中等生态风险。结合渤海和北黄海西部表层样主量元素的分布，柱状样B18的0-40cm的主量元素组成和三根柱状样的²¹⁰Pb测年结果，对百年尺度黄河入海物质的“源”到“汇”问题进行了研究。结果表明：CaO／TiO₂和CaO／Al₂O₃是黄河入海物质在渤海扩散范围的有效指标，CaO／TiO₂=6和CaO／Al₂O₃=0.3可以作为黄河入海物质在渤海扩散范围的边界值。黄河入海物质由于受絮凝沉积作用影响，在河口区形成两个细沉积中心；河口区的物质再悬浮，在潮流的作用下向渤海湾输送；且黄河入海物质在冬季风的作用下向东输送，细颗粒物质可以转过山东半岛东端，进入南黄海。CaO／TiO₂和CaO／Al₂O₃的值表明，黄河物质对北黄海中部泥质区的贡献较小。从三根柱子的²¹⁰Pb测年结果证实，黄河物质沿渤海湾南岸向西部的输送和向北北东方向的输送强度强于向西北方向输送。B18为黄河和滦河物质混合的产物。B18的粒度、CaO／TiO₂和CIA大约从1976年(²¹⁰Pb年龄)发生明显变化，表明黄河向渤海湾输入的物质从1976年以来明显减少，是由于黄河1976年人工改道和入海泥沙的减少，以及渤海盐度场和环流结构改变共同作用造成的。对渤海和北黄海西部表层样沉积物的REE研究表明：渤海和北黄海西部表层沉积物∑REE，∑HREE和∑LREE和沉积物的粘土含量（％）正相关。辽东浅滩、辽东湾西侧长兴岛附近、渤海海峡，滦河口，和烟台东北侧附近海区的∑LREE／∑HREE，La／Yb和La／Sm值基本均相对高于其它海域，Eu／Eu^*基本上大于1，证明这些地区附近海域的沉积物可能部分来源于陆上太古代岩石。Ce／Ce^*在大连南侧，曹妃甸，烟台附近以及北黄海中部泥质区均＞1，说明这些海区可能处于相对强的氧化环境。青岛气溶胶的元素Fe，Ti，Mn，V Ni，Cu，Pb，Zn和Cd均呈现季节变化的特点：夏季最低，冬季最高。S季节变化比较特别，夏季含量高于春季和秋季。沙尘事件期间，Fe，Ti，Mn,V，Ni和Cu含量明显增加，达到全年最高值。Pb，Zn，Cd，S虽然在沙尘：事件期间也明显增加，但低于冬季平均值。对各元素的富集系数（EF）进行了分析，结合主成分分析和聚类分析的结果，可以看出，Ti和Mn可能主要来源于土壤；V也可能来源于土壤，船排放物可能是V的一个较小的来源。沙尘期间，Cu主要来源于土壤，但在非沙尘期间，人为源对Ni和Cu具有较高的贡献。全年的S，Pb，Zn和Cd主要来源于人为源，即使在沙尘期间，人为源仍然是S，Pb，Zn和Cd的主要来源。自然源贡献了全年测试元素的大约60％，人为源可能贡献了30％左右。利用X射线荧光光谱（XRF）元素分析仪和热电离质谱仪（TIMS）就东海近岸泥质区S5孔百年尺度(²¹⁰Pb定年)Pb和Pb稳定同位素组成的高分辨沉积记录进行了研究。结果显示闽浙沿岸泥质区的Pb含量背景值为32μg g^-1，²⁰⁶Pb／²⁰⁷Pb的背景值为1.195。S5铅通量从19世纪80年代开始迅速升高，1999年达到最高，之后迅速降低到2002年的31 mg cm^-2 yr^-1。²⁰⁶Pb／²⁰⁷Pb从1860年到20世纪60年代基本稳定，平均值为1.195；之后逐渐降低，1980年后降低幅度尤为明显，2000年达到最小值1.165；2000-2002年，²⁰⁶Pb／²⁰⁷Pb升高，2002年达到1.185。S5铅通量和铅稳定同位素组成的变化反映了中国经济的发展，特别是含铅汽油的使用和禁用。特大洪水可能会导致更多的人为源Pb进入闽浙沿岸泥质区。由于经济发展时期不同，中国的含铅汽油的禁用大约比欧美国家晚大约20年，中国环境中Pb的历史纪录明显不同于欧美国家。本论文受国家973项目“中国典型河口海岸带陆海相互作用及其环境效应（2002CB42400）第4课题：黄河三角洲海岸蚀积转换机制和趋势预测”（2002CB42404），“中国东部陆架边缘海海洋物理环境演变及其环境效应（2005CB422300）第4课题：颗粒物源-汇效应与沉积记录对海洋物理环境演变的响应（2005CB422304）”和国家海洋局“908”专项：“CJ02区块海底底质调查与研究（908—CJ02）”联合资助。更多还原

【Abstract】 Yangtze River and Yellow River transport numerous materials, including a lot ofpollutant, to the marginal seas of China, and the dust storm of the East China is animportant passage, delivering the materials to the Pacific. The mud areas in theSouthwest of the Cheju Island, the South Yellow Sea, the Bohai Sea, and along theFujian-Zhejiang Coast are the sedimentary center of the fine matter.Firstly, the mechanism of the colloidal flocculation is described and introduced todiscuss the formation of fine mud areas in ocean in my dissertation. The mud areas inthe marginal seas of China are all formed in the upwelling areas where the conditionof the physical chemistry （temperature and salinity and so on） changes regularly,which leads to the flocculation and sink of the colloidal solid.Major elements of 118 surface sediment samples in the Bohai Sea and the West ofthe North Yellow Sea and 57 sediment samples of sediment core B18 in the BohaiBay were analyzed by the ICP-AES, minor elements, including REE, of all sedimentsamples above were determined by the ICP-MS, and the compositions ofthe grainsize of all samples were analyzed by the Laser particle size analyzer. Three sedimentcores of B178, B18, and A435 from East to west in the Bohal Bay were dated by themethod of ²¹⁰pb.The distributions of the toxic elements showed that clear anthropogenic inputs oftoxic elements mainly from the rivers to the Bohai Sea, and the Dalian industrialregion was the important source of the toxic-elements in the West of the North YellowSea. The results indicated the potential pathways of trace metals via the transport ofsediment from the coast to the Bohai Sea and the West of the North Yellow Sea. The high concentrations of toxic elements near the Yellow River Delta were caused by theprocesses of adsorption and coagulation of dissolved trace metals with particulates aswell as aggregation of particulates between freshwater and marine water zones. Theresults of EFs and the correlation with the Fe indicated that As and Sb may be derivedmore from the anthropogenic sources, and Ers of As and Cd indicated that they maylead to heavier ecological risks in the studied region. The results of PCA indicated themost of the elements analyzed may be derived from the natural sources, and the BohaiBay may be the heaviest polluted areas among the four parts of the Bohai Sea. Theremay be considerable ecological risk in the most of the Bohai Bay, the Yellow Rivermouth and the southwest of the Liaodong Bay. In the West of the North Yellow Sea,the pollution of toxic elements, especially As, near Dalian may be much heavier, andthe sea area near Dalian may be in moderate or considerable ecological risk,influenced by the Dalian Industrial area region.The distributions of the major elements in the Bohai Sea and the West of the NorthYellow Sea, the compositions of the major elements of the sediment core B18（0-40cm）, and the ²¹⁰pb dating results of three sediment cores were used to study thetransport process of the Yellow River material into the sea. The results indicated thatCaO/TiO₂ and CaO/Al₂O₃ were the effective indicators of the diffusing range of theYellow River materials in to the sea, and CaO/TiO₂=6 and CaO/Al₂O₃=0.3 were theboundary values of the diffusing range of the Yellow River material in to the sea.There were two centers of the fine sediments near the Yellow River delta, influencedby the flocculation process. The sediments near the Yellow River mouth wereresuspended, and transported to the Bohai Bay by the tidal current. Impacted by thewind in winter, the sediments near the Yellow River delta were transported to the east,and the fine materials could enter the South Yellow Sea through the tip of theShandong Peninsula. The Yellow River’s contribution to the center of the NorthYellow Sea may be small, indicated by the CaO/TiO₂ and CaO/Al₂O₃. The ²¹⁰Pbdating results of three sediment cores indicated that the materials from the YellowRiver were transported more to North-Northeast and the west along the south coast ofthe Bohai Bay than it to the Northwest. B18 was a mixture of the Yellow River and Luan River materials. Since 1976, the grain size composition, CaO/TiO₂ and CIA ofB18 had changed remarkably, indicating that the Yellow River materials transportedinto the Bohai Bay had decreased distinctly since 1976, which was caused by theman-made changing of the Yellow River channel, the decreasing of the Yellow Riversediments into the sea, and the changing of the salinity field and the circulationstructure in the Bohai Sea.∑REE,∑HREE and∑LREE were positive relation with the clay content （%） of thesurface sediments of the Bohai Sea and the West of the North Yellow Sea. In the westof the Liaodong Peninsula near the Changxing Island, Liaodong shallow bank, theBohai Strait, the Luan River mouth, and the Northeast area near the Yantai,∑LREE/∑HREE, La/Yb and La/Sm, were higher than them of other regions, andEu/Eu^* was higher than 1, indicating that the sediments in these regions may be partlyderived from the Archean rock on the land. Ce/Ce^* was higher than 1 in the South ofDalian, around Caofeidian, near Yantai, and the center mud of the North Yellow Sea,indicating that the oxidized condition was relatively stronger in these regions.All the analyzed elements in the aerosols of Qingdao displayed strong seasonalvariations: the concentration of Fe, Ti, Mn, V, Ni, Cu, Pb, Zn, Cd was the lowest inthe summer, and the highest in the winter. As an exception, the concentration of S insummer is higher than those in spring and autumn. During the dust episode, theconcentration of Fe, Ti, Mn, V, Ni, Cu increased remarkably, while the concentrationsof Pb, Zn, Cd, S were obviously lower than that in winter though they also increasedremarkably. Ti, Mn are mainly derived from the soil source. V in the atmosphere ismainly derived from the soil source, with minor contribution from ship emission. Theanthropogenic source has a relatively higher contribution to Ni and Cu in the non-dustsamples, while Cu is mainly from soil source during the dust episode. The S, Pb, Znand Cd are mainly derived from the anthropogenic source, even during the dustepisodes. The natural sources contributed about 60% to the sum of measured elementsand anthropogenic sources contributed about 30%.The rapid economic development in the Yangtze River Delta （YRD）, China in thelast three decades has had a significant impact on the environment of the East China Sea （ECS）. Lead isotopic compositions of a ²¹⁰pb dated sediment core collected fromthe coastal ECS adjacent to the Yangtze River Estuary were analyzed to track the Pbpollution in the region. The baseline Pb concentration in the coastal ECS adjacent tothe YRE was 32μg g^-1, with the corresponding ²⁰⁶pb/²⁰⁷pb of 1.195. The Pbconcentrations (average, 31^-2 mg g^-1) and fluxes (average, 30^-2 mg cm^-2 yr^-1) wererelatively constant from w1860 to mid-1980s, and they increased rapidly from themid-1980s to 1999, peaking in 1999 at 65 mg g^-1 for the concentration and 61 mgcm^-2 yr^-1 for the flux before decreasing sharply to 36 mg g^-1 and 31 mg cm^-2 yr^-1,respectively, in 2002. ²⁰⁶pb/²⁰⁷pb was constant from w1860 to mid-1960s （average,1.195）, and decreased from the mid-1960s to 1.165 in 2000 before rising to 1.185 in2002. The variations of Pb flux and stable Pb isotopic composition in the study areareflected the impacts of the economic development, in particular the leaded gasolineusage in China. The severe flood of the Yangtze River could contribute moreanthropogenic Pb to the coastal ECS. Due to the different time of economicdevelopment, especially about 20 years lag of the phasing-out of leaded gasoline inChina, the historical records of Pb in the environment of China were obviouslydifferent from those of most European countries and the United States.更多还原