渤黄海沉积物中的多环芳烃和多氯联苯及其与生态环境的耦合解析

IOCAS-IR > 海洋环流与波动重点实验室

	渤黄海沉积物中的多环芳烃和多氯联苯及其与生态环境的耦合解析
其他题名	PAHs and PCBs biogeochemical characteritics in the sediments and coupling with the eco-environment in the Bohai Sea and the Southern Yellow Sea
	张蓬
学位类型	博士
	2009-05-19
学位授予单位	中国科学院海洋研究所
学位授予地点	海洋研究所
关键词	多环芳烃多氯联苯沉积物生态环境耦合解析渤海湾南黄海
摘要	海洋沉积环境中多氯联苯（PCBs）和多环芳烃（PAHs）的研究对于揭示其污染历史、来源途径、迁移转化以及评价其对环境的潜在生态风险都有重要的科学意义和应用价值，本研究选择我国典型近海中比较开阔的南黄海和受人为影响严重的渤海湾沉积物中的PAHs和PCBs作为主要研究对象，结合对生态环境对应关系的剖析，系统研究了沉积物中PAHs和PCBs的地球化学分布特征、影响控制因素、演变趋势、潜在生态风险等，获得了以下系统的认识： 1.南黄海表层沉积物中多环芳烃和多氯联苯的分布与沉积类型及模式相一致，受控于“沉积类型-动力过程-来源途径”。PCBs含量（范围：518～5848 pg/g，平均值：1715 pg/g）低于受人为影响严重的长江口、珠江口和渤海，分布具有中部海区＞东部海区＞西部海区的特征；PCBs随着沉积物粒径的减小和粘土含量的增加而增加，且与总有机碳（r=0.61，p＜0.01）含量呈显著线性正相关，表明PCBs在沉积物中的分布受控于被水动力过程原动力控制的沉积类型与沉积模式。 2. 1914～2004年间，南黄海沉积物中PAHs和PCBs的变化比较显著，在时间序列上经历了三个明显的不同阶段。近90年来，PAHs和PCBs在柱状样中垂直分布随深度的增加而降低，即近年南黄海沉积物中PAHs和PCBs的残留水平比上世纪初明显增加。其中1914～1932年间，PAHs和PCBs保持在较低的水平；1932～1962年间，PAHs和PCBs的含量发生急剧的变化，在1932～1944和1956～1962年两个时间段，PAHs和PCBs的含量达到峰值；自1962年至今，PAHs和PCBs呈稍有增加趋势。PAHs的组成和特征组分比值分析显示，1920～1944年间PAHs主要来自石油产品泄漏，1944～1980年间，主要来自草/木材/煤燃烧，1980年至2004年则显示出石油和燃烧产物混合来源的特征。 3.渤海湾沉积物中的PAHs、PCBs、DDTs和HCHs的分布模式不同，反映了这四种污染物的地球化学行为存在着明显的差异性。PAHs、PCBs、DDTs和HCHs的含量范围为149.0～393.4 ng/g，360.8～1728.3 pg/g，462.2～2007.3 pg/g和4.31～33.8 ng/g。马颊河口、海河口和黄河口附近的海区的沉积物中PAHs和PCBs的含量显著高于渤海湾内其它站位，DDTs在湾外沉积物中的含量大于湾内，在海河口附近站位测得HCHs含量的最高值，在其它站位其浓度变化不大。PAHs特征成分的比值显示渤海湾沉积物中PAHs主要来源于草/木材/煤燃烧的产物经过大气的输运过程进入水体；DDTs和HCHs的组成显示，在DDTs和HCHs被禁用后仍有新的输入源。 4.南黄海沉积物POPs总体水平不高，其环境污染危害和潜在生态风险不大，从沉积物POPs的角度来说南黄海的环境质量较好。潜在生态危害指数评价表明，渤海湾沉积物中芴可能会产生潜在的生态风险，DDTs和HCHs的含量低于一类沉积物质量标准值，总体而言，其沉积物质量良好，潜在生态风险较低。论文的创新性点在于：1）首次研究了近百年南黄海沉积物中多环芳烃和多氯联苯的演变趋势，判断了其来源并对近百年二者的潜在生态风险进行评价。2）系统剖析了南黄海及渤海湾的生态环境与PAHs和PCBs的耦合关系，对阐明POPs的毒理效应有重要的科学意义。3）系统解析了渤海湾沉积物中PAHs，DDTs和HCHs的污染现状，来源和迁移途径，可为科学开发和利用渤海海域提供重要的理论依据。
其他摘要	The studies on the residue of Polycyclic Aaromatic Hydrocarbons (PAHs) and Polycyclic Biphenyls (PCBs) in the sediment environments are of important scientific and practical significance in revealing their sources, transition modes, contamination history and potential threat on environments. In this study, PAHs and PCBs in the sediments from the southern Yellow Sea and Bohai Bay, typical semi-enclosed seas, were analyzed with GC/MS. By virtue of systemic analyzing the coupling relationships between PAHs and PCBs concentrations and the sediment environment characteristics, as well as the factors controlling their adsorption and variation tendencies, were studies in detail, which were helpful to evaluate and establish sound scientifically priorities for future managements for them. Four conclusions were drawn as followed: The horizontal distribution pattern of PCBs in the sediments from the southern Yellow Sea was coincident with the sedimentation pattern and controlled by the mode of ‘sedimentation type-dynamical process-sources’. PCBs concentrations ranged from 518 to 5848 pg/g, with the average of 1715 pg/g. The horizontal distribution of PCBs followed the sequence: the middle area＞the west coast＞the east coast. PCBs concentrations increased with the sediment particle size decreasing and the clay contents increasing, moreover, PCBs concentrations positively linearly related with TOC contents, suggesting that the adsorption of PCBs were predominantly controlled by sediment texture and the organic matter. As well-known, the hydrodynamics conditions were the driving force to the particles sedimentation. Consequently, the driving factor controlling PCBs distribution was the hydrodynamics conditions of the southern Yellow Sea. From 1914 to 2004, PAHs and PCBs concentrations varied significantly, so that the past century was divided into three periods based on their concentrations variation. The vertical distribution illuminated that PAHs and PCBs levels declined with depth, indicating that their concentrations at present were much higher than in the early of this century with respect to sedimentation time. Therein, the concentrations of PAHs and PCBs kept in low constant level from 1914 to 1932. During the period of 1932~1962, PAHs and PCBs underwent huge variation with the variation range of 24~62%. Their discharge was up to the peaks in the periods of 1932~1944 and 1956~1962. From 1962 to 2004, PAHs and PCBs levels elevated slightly. PAHs compositions and isomeric compound ratios were generally used as the indexes to apportion PAHs sources. From 1920 to 1944, PAHs mainly derived from petroleum production; from 1944 to 1980, the predominant source was the production from grass/wood/coal combustion; and from 1980 to 2004, PAHs composition presented the multi-sources of petroleum and combustion. The distribution modes of PAHs, PCBs, DDTs and HCHs in the sediments collected from Bohai Bay were not in the same, indicating that difference existed in their biogeochemical behavior and sources. The concentrations of PAHs, PCBs, DDTs and HCHs were in the range of 149.0~375.3 ng/g, 360.8~1728.2 pg/g, 462.2~2007.3 pg/g and 4.3~33.8 ng/g. PAHs and PCBs concentrations were higher at the stations close to Majiahe River, Haihe River and Huanghe River. DDTs concentrations in the off-bay stations were higher than those in the in-bay stations, while no significant variations of HCHs concentrations were found. The isomeric compounds ratios suggested that PAHs in the sediments from Bohai Bay mainly derived from grass/wood/coal combustion and transferred into the aquatic environment through atomospheric movement. DDTs and HCHs compositions indicated that DDTs and HCHs were still in use after their legal banish. After comparing the POPs concentrations in the sediments from the southern Yellow Sea and Bohai Bay with the eco-risk thresholds, it was found that the quality of sediments of the southern Yellow Sea was clear and the potential risk rarely occurred. However, Fluorene and “dioxin-like PCBs” could probably pose risk on the environment of Bohai Bay. The original ideas of this paper were that: 1) The PAHs and PCBs distribution variation mode in the past century were studied for the first time, meanwhile, their sources and contamination history were traced and their potential eco-risk were evaluated. 2) The coupling relationships between PCBs and sediment environment were analyzed systemically, which was of precious scientific significance for assess their toxicity. 3) The sources, transition modes and contamination status of PAHs, PCBs, DDTs and HCHs in the sediments from Bohai Bay were analyzed in detail. The results could lay down the theorical foundation for developing and using the Bohai Sea properly and protecting the Bohai Sea environment.
页数	141
语种	中文
文献类型	学位论文
条目标识符	http://ir.qdio.ac.cn/handle/337002/909
专题	海洋环流与波动重点实验室
推荐引用方式 GB/T 7714	张蓬. 渤黄海沉积物中的多环芳烃和多氯联苯及其与生态环境的耦合解析[D]. 海洋研究所. 中国科学院海洋研究所,2009.

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