多环芳烃(Polycyclic aromatic hydrocarbons，PAHs)和有机氯农药(Organochlorine Pesticides，OCPs)等疏水性有机污染物，具有致癌性、致畸性、生殖毒性和免疫毒性。因此，其在水环境中的分布特征和环境行为受到人们的广泛关注。辽河流域是我国七大江河中的重要水系，其污染日益严重。尽管如此，有关大辽河入海口的疏水性有机污染物污染现状的研究鲜有报道。因此，研究辽东湾营口河口有机污染问题就变得十分必要。此外，PAHs由于溶解度低、疏水性强，进入水体后容易被颗粒物吸附，并随其在沉积物中积累，使沉积物成为环境中PAHs的蓄积库，但再悬浮过程可使颗粒物表面的吸附态污染物发生解吸而再次进入水相，并导致水相中污染物浓度增加数倍以上，使水相再次受到污染。鉴于此，本论文以辽东湾营口河口为研究区域，以辽东湾营口河口的表层水、悬浮颗粒物和沉积物为研究对象，以典型疏水性有机污染物PAHs和OCPs为研究目标物，探讨有机污染物污染特征及生态风险，另一方面，研究典型疏水性有机污染物PAHs在沉积物再悬浮过程中的二次释放行为。研究表明，辽东湾营口河口PAHs的浓度随着距离河口的远近发生变化，离河口越远，沉积物中PAHs的浓度越低，这是由于河口地区的絮凝作用以及水流对PAHs的稀释作用造成的。PAHs的组成主要以2环和3环PAHs为主，反映该区域有近期的燃料和煤燃烧来源PAHs的输入，这些低环的PAHs吸附在颗粒物表面，沉降在研究区域。对PAHs的来源分析表明，研究区域的PAHs来源是混合源。利用生物效应指标对辽东湾营口河口的PAHs污染进行评价，结果表明很多站点低环的PAHs可能会对一些生物产生毒性效应。通过对沉积物柱状样中PAHs的垂直埋藏分布研究表明，1935年以前工业化生产还未开始之前，PAHs的浓度较低，PAHs主要来源于木柴的燃烧和自然森林大火。而1965-1975年之间总PAHs的浓度有所降低，这与中国在此期间发生的文化大革命工业和农业生产停滞不前有关。19世纪80年代PAHs的浓度有一个比较大的增长，反映中国改革开放以后经济和城市化的快速发展。19世纪末和20世纪初这段时间PAHs的浓度快速增长，显示这段时期辽东湾营口河口相关区域工业化和城市化的快速推进。通过对沉积物柱状样中OCPs的垂直埋藏分布研究表明，HCH是两个柱状样中检出频率和检出浓度最高的有机氯农药，因此可以认为HCH是该河口柱状样中的主要有机氯农药污染物。两个柱状样六六六的浓度峰值出现在10cm左右、25cm左右和40cm左右深度附近。DDT的浓度较小，垂直变化不明显。有机氯农药的垂直分布特征表明六六六主要来源于历史遗留和新的林丹的输入。从生态风险分析可以看出，柱状沉积物中有些柱状样样品的DDT含量超过ERL标准，这表明研究区域DDT污染存在生态风险。不同剪应力条件下，含有不同浓度的PAHs的沉积物再悬浮过程中，含有较低PAHs浓度的沉积物对应的上覆水中PAHs的浓度随着剪应力和沉积物的浓度的不同并未发生明显变化。不过，含有较高PAHs浓度的沉积物对应的上覆水中PAHs的浓度随着剪应力的不同有显著的变化。低分子的PAHs较之高分子的PAHs更易释放到水中，因为高分子的PAHs具有更高的疏水性，且更易吸附在颗粒物上。悬浮颗粒物上的PAHs的体积浓度随着剪应力的增大而增大。两种不同沉积物分别加入海水、稀释10倍海水和稀释100倍海水进行再悬浮实验。随着再悬浮的持续，总悬浮颗粒物浓度略微下降，且砂质含量高的沉积物1再悬浮过程中再悬浮颗粒物的总颗粒物浓度含量偏高。上覆水体PAHs浓度总体上随着再悬浮的持续而增加。沉积物1的海水中PAHs的浓度较之稀释10倍和稀释100倍海水中PAHs的浓度要大，这可能是由于溶解性有机碳对PAHs的吸附作用。沉积物2的海水中PAHs的浓度与稀释10倍和稀释100倍海水中PAHs的浓度大小接近。

Polycyclic aromatic hydrocarbons (PAHs) and Organochlorine Pesticides (OCPs) are of environmental significance due to their widespread distribution in the environment and potential toxicity to organisms. Due to their low water solubility and high hydrophobicity, PAHs are rapidly bound to particles and subsequently deposit in sediment once released into aquatic environment. As a result, sediments become a huge repository for these contaminants. As one of the important industrial bases with oil, chemical and steel factories in the northeast part of China, the Liaohe River watershed has been subject to heavy anthrogenic influences as a result of the rapid development of economy in the past ca. 50 years, and has resulted in significant stress to Daliao River Estuary in Liaodong Bay of Bohai Sea (China) and its surrounding environments. In this study, the distribution of PAHs and OCPs in the Daliao River Estuary of Liaodong Bay, Bohai Sea (China) and the release behavior of PAHs during the Daliao River Estuary sediment resuspension were investigated.Results indicated that PAH concentrations decreased offshore, reflecting that PAHs in water deposited when water flew through the mouth of Daliao River Estuary. The composition of PAHs in the four phases was mainly 2-, 3-ring PAHs, indicating a relatively recent local source and coal combustion source of PAHs, which strongly sorbed onto the surface of fine particles and fallout in the study area. Analysis of the possible source of PAH suggested a complicated, combined PAHs source in study area. Low weight molecular PAHs concentrations in sediment of the Daliao River Estuary were sufficiently high at many sites to cause toxicity to certain exposed organisms.The sedimentary record of PAHs in the Daliao River Estuary of Liaodong Bay, Bohai Sea reflected the industrial development and urbanization history of the surrounding region in the last 80 years. Based on the dating profile of the sediment cores, it appeared that prior to 1935, pre-industrialization levels of the PAHs were low (<850 ng g-1). The dominant source of these PAHs probably was from the burning of wood or coal, or from natural forest fires. The decline in the concentrations of total PAHs for sediment cores between about 1965-1975 might be due to the cultural revolution in China, which led to siginificant declines in the country’s agricultural and industrial production. The sharp increase in total PAHs concentration in 1980s reflected the rapid economic growth and urbanization since the economic reform in the country in the late 1970s. Concentrations of total PAHs started to increase around the turn of the century in response to increasing urbanization and industrialization around the Daliao River Estuary.The predominant OCPs pollutants in the two sediment cores were HCH, because they were the most detected pollutants and their concentrations were the highest. The peak of OCPs concentration appeared in the vicinity of about 10 cm, 25 cm and 40 cm depth. The concentration of DDT was lower, which didn’t show vertical variation obviously. It was found that usage of OCPs in the history was the main source in Daliao River estuary in this study, while the usage of lindane became a new source of OCPs in this area. From the perspective of ecological risk, the concentrations of DDT in surface water and sediment had exceed the ERL standards, which reflected the potential ecological risk in the study area.Remobilization of PAHs during sediment resuspension was investigated using a PES device. Concentration of total PAHs in overlying water for original and spiked 500 ng g-1 PAHs sediments didn’t show much difference with the different shear stress. However, those for spiked 1000 and 2000 ng g-1 PAHs sediments showed significant increase in the concentration when shear stress increased. High molecular weight PAHs were much more difficult to release into overlying water than the low molecular weight PAHs due to their low water solubility and strong affinity for particles. During the resuspension process of sediments, significant amounts of particulate PAHs were introduced into the water column. The total amount of solid-phase PAHs on volume normalization generally increased with the increase of shear stress. However, on mass weight basis, the PAHs’ concentration decreased from 2106.44 ng g-1 at 0 N m-2 to 1276.03 ng g-1 at 0.4 N m-2 for original sediment. The trend was not observed for spiked sediments.Two sediment cores with different physical and chemical characteristics were resuspended with seawater, 10 times diluted seawater and 100 times diluted seawater for 24 h under 0.5 N m-2. Total suspended solids (TSS) generally decreased with the increase of shear stress. PAHs concentrations in overlying water showed generally increase over time. PAHs concentrations in overlying seawater were higher than that of 10 times diluted seawater and 100 times diluted seawater for sediment 1, it might due to the absorption behavior of PAHs onto DOC. PAHs concentrations in overlying seawater were close to that of 10 times diluted seawater and 100 times diluted seawater for sediment 2, because the reaction between the absorption behavior of PAHs onto DOC and the inhibition on desorption of PAHs of salinity.