Large-scale marine resource development and utilization projects will disturb sediment, cause sediment resuspension, and furtherly cause the release of heavy metals, threatening the safety of ecosystems and biodiversity. This study described the sources of heavy metals in marine sediment, sorted out the simulation devices of heavy metal release caused by the external disturbance and sediment resuspension, detailed the influencing factors and rules of heavy metal release, summarized the kinetic models of heavy metal release, pointed out the current research progress and problems of heavy metal release from sediment, and put forward suggestions. It is found that the current researches on the release of heavy metals in sediment are limited to indoor simulation, and the simulation disturbance devices cannot accurately judge the quantitative relationship between the simulated disturbance intensity under experimental conditions and the one under natural conditions, such as wind wave and current. Among them, particle entrainment simulator (PES) device, EROMES device and Y-type resuspension device are more suitable for simulating the hydrodynamic sediment resuspension process in shallow water. The annular flume device can better simulate the marine environment. Studies on the factors influencing the release of heavy metals mainly focus on the physical and chemical properties of sediment and overlying water conditions, among which the physical and chemical properties of sediment, dissolved oxygen (DO), redox potential (Eh) and pH of overlying water are the main regulatory factors for the release of heavy metals from sediment resuspension. Elovich model and double constant model have a wide range of application in describing the release kinetics of heavy metals. It is pointed out that in the future, in-situ test experiments combined with indoor physical model tests and numerical simulation can be carried out to build a dynamic model of heavy metal release from sediment that is closer to the natural situation, which can provide references for the study of heavy metal release in marine sediment caused by ocean engineering and the formulation of relevant protection and restoration schemes.

The harmful effects of marine microplastic pollution on organisms have attracted widespread attention, but research on the toxic effects of combined pollution formed by microplastics adsorbing petroleum in intertidal sediments is relatively scarce. In this study, acute toxicity of the single and combined pollution of Polyethylene microplastics (PE MPs) and diesel on Tegillarca granosa after 96 h exposure was investigated in terms of oxidative stress related biochemical indicators, histopathology, DNA damage and gene expression, respectively. The results showed that microplastics-diesel combined exposure resulted in increased SOD activity in both the gills and the visceral mass of T. granosa, whereas GPx and GST activities were inhibited. However, no significant change in MDA content was observed under short-term exposure conditions. The Integrated Biological Responses version 2 (IBRv2) index revealed that the gills exhibited higher sensitivity to the combined pollutant. High-concentration combined exposure induced histopathological alterations (gill swelling, digestive tubule necrosis of the visceral mass) and DNA damage. Furthermore, high-concentration combined pollution upregulated the gene expression of cytochrome P450 Family 2 (CYP2 family), GST, CAT, GPX, and SOD1, while downregulating the KEAP1. It indicated that combined pollutants can regulate antioxidant genes by activating the cytochrome P450 (CYPs) enzyme system and the KEAP1-NRF2 signaling pathway, interfere with the antioxidant defense system of T. granosa, and produce an enhanced toxic effect. The research revealed the toxic effects and molecular mechanisms of microplastic-petroleum combined pollution on T. granosa, providing a scientific basis for assessing the ecological risks of combined pollution in marine environments.

Marine oil spills lead to intertidal sediment pollution, causing benthic bioaccumulation and toxicity. However, relatively few studies have been conducted on the effects of crude oil sediment pollution on benthos. In this study, Sinonovacula constricta was used as the research object in a sediment environment to study the accumulation and elimination effects of S. constricta on long-term exposure to crude oil pollution as well as the toxicity effects at the biochemical and tissue levels through laboratory exposure tests. The objective of this study was to provide theoretical support for monitoring the biological toxicity of intertidal crude oil pollution. The results showed that S. constricta accumulated petroleum hydrocarbons in the sediment, which were positively correlated with pollution concentration and time. The fitting results of the two-compartment kinetic model were good and could be applied to the accumulation and elimination of sediment crude oil pollution. The activity of antioxidant enzymes and the content of malondialdehyde in the gills were mainly induced, and there was a dose- and time-dependent relationship. Crude oil pollution can cause digestive tube ablation, lumen swelling, and blood cell infiltration in the viscera of S. constricta. S. constricta can be used as an indicator organism for oil pollution in the intertidal zone, and its gills and visceral mass can be used as target tissues.

Two physical models were used to simulate the infiltration and redistribution process of light crude oil after leakage in a heterogeneous soil layer following water level variation and rainfall. Migration fronts and redistribution characteristics of oil during gravity seepage, water level variation, and rainfall were obtained using charge-coupled device (CCD) camera shooting and cyan–magenta–yellow‒black (CMYK)-based gray analysis, which were employed efficiently and at a low cost. Then, the influencing factors and migration mechanisms were examined. Finally, the soil water and oil contents were measured to verify the simulation results. The results are as follows: (1) the geologic lens and fine–coarse interface can intercept oil, resulting in a local highly contaminated area. (2) The crude oil infiltration path and velocity varied greatly with the different soil types and initial water contents. Within a certain range, the higher the initial water content is, the higher the lateral and vertical infiltration speeds. (3) The oil redistribution process was dominated by vertical infiltration under the condition of water level variation or rainfall, but oil–water displacement and the capillary pressure caused some oil to move horizontally near the geologic lens and fine–coarse interface. (4) Water level variation resulted in a synchronous rise or fall of the oil accumulation area, but rainfall caused it to move up. (5) Water level variation and rainfall imposed a certain influence on the periodic accumulation and release of crude oil in heterogeneous soil, especially in the presence of geologic lenses and lithologic interfaces.

以泥蚶鳃和内脏团抗氧化酶为生物标志物,探究潮间带沉积物不同浓度原油污染72 h后对泥蚶急性毒性效应.研究表明,泥蚶鳃超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和谷胱甘肽硫转移酶(GST)酶活性均高于内脏团,而内脏团中谷胱甘肽过氧化物酶(GPx)则更高;随着原油污染浓度增加,泥蚶鳃SOD和GST,内脏团CAT,低浓度组中GPx酶活性均呈先升高后降低趋势,表明低浓度原油污染下泥蚶酶活性升高以对抗污染造成身体机能损伤;原油浓度逐渐增加,酶活性则受抑制.泥蚶鳃GPx酶活性最大诱导倍数高于其他抗氧化酶,结合不同组织抗氧化酶活性大小及差异显著性分析发现,泥蚶鳃GPx酶活性更敏感,可以作为生物标志物应用于海洋原油污染的监测.

通过研究不同浓度原油污染对缢蛏(Sinonovacula constricta)鳃和内脏团抗氧化酶活性、脂质过氧化及鳃结构的影响,结合综合生物标志物响应(IBR),探讨潮间带原油污染对生物的毒性效应.结果显示:在剂量-效应方面,2种组织超氧化物歧化酶(SOD)活性和内脏团中谷胱甘肽过氧化物酶(GPx)总体上表现为低浓度诱导、高浓度抑制效应;SOD诱导与过氧化氢酶(CAT)抑制同时出现,规律大致相反.在时间-效应上,SOD活性呈升高-降低-升高的趋势,CAT与GPx呈先降低后升高的趋势;谷胱甘肽硫转移酶(GST)在鳃中呈现先升高后降低的趋势,酶活性最高为371.663U/mgprot.暴露前期(6h)缢蛏2种组织中丙二醛(MDA)含量显著增加,鳃和内脏团中MDA含量最高值分别为5.030和10.705nmol/mgprot,后期逐渐平稳.IBR结果表明鳃中生物标志物对原油污染敏感度更高.原油暴露会使鳃丝结构发生变形或引起鳃丝脱离等现象.研究表明,缢蛏鳃更适宜作为潮间带原油暴露生物监测与评价的器官.

Under tidal scouring, residual petroleum in the intertidal sediment after oil spills could release again, causing secondary pollution in the marine ecosystem. The current study aimed to investigate the dynamic process and principles of crude oil release from silty intertidal sediment under different influencing factors and screened for the key factors. In this paper, the fitting equations and correlation between the release amount and various factors were explored through the single-factor and orthogonal experiments. Then, the key influencing factors were selected for multi-factor fitting of the release amount. The results showed that the oil release amount rose with the increase in oil concentration, oscillation frequency, and release time, but decreased with an increase in salinity. As the pH decreased, the oil release amount increased. The relationship between release amount and concentration/oscillation frequency can be equipped by the polynomial equation, and the average R2 was 0.95 and 0.84, respectively. The release amount can be fitted by the Lagergren pseudo-second-order kinetic equation with time, with the average R2 0.89. The pH was negatively correlated with the release amount in the fresh contaminated sediment but positively correlated with the weathered one. The correlation between each factor and oil release amount was ranked (from large to small) as oil concentration, oscillation frequency, salinity, time, and pH. At last, a polynomial equation can be fitted between the key influencing factors (oil concentration and oscillation frequency) and the release amount. The results can provide a theoretical basis for predicting the secondary pollution owing to the oil re-release from intertidal sediment.

随着海洋石油开发及运输的不断发展,溢油事故时有发生,给潮间带生物带来不同程度的影响.以泥蚶(Tegillarca granosa)为研究对象,采用潮间带原油污染生物暴露室内模拟试验及数据统计检验,结合综合生物标志物响应(IBR)星状图,探讨潮间带沉积物原油污染对泥蚶鳃和消化腺中不同抗氧化酶活性的影响,筛选最优生物标志物.结果表明:①受低浓度原油污染时超氧化物歧化酶(SOD)活性总体表现为被诱导,受高浓度原油污染时总体表现为被抑制,且其在消化腺中的平均活性(132.29 U/mg)约为鳃中(69.34 U/mg)的2倍.②过氧化氢酶(CAT)活性在时间-效应上与SOD活性变化规律相似,但其响应时间具有滞后性.③鳃中谷胱甘肽转硫酶(GST)活性在受污染第1天总体表现为被抑制,而消化腺中GST活性在第3、12天时被抑制的效果更明显.④鳃中谷胱甘肽过氧化物酶(GPx)活性在污染第3天较早被激发,且消化腺中GPx活性最大诱导率和抑制率都出现在低浓度(500 mg/kg)原油污染时.⑤泥蚶鳃和消化腺的IBR值均随暴露时间的增加呈先降低后升高的趋势,且与4种酶活性变化趋势基本相同.研究显示,4种主要抗氧化酶在消除活性氧自由基(ROS)上具有协同作用,GST可作为原油污染短期监测的生物标志物,而IBR可作为综合生物毒性评价的指标.

以大弹涂鱼(Boleophthalmus pectinirostris)鳃和肝脏中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSH-Px)和谷胱甘肽硫转移酶(GST)为生物标志物,探究潮间带沉积物不同浓度原油污染48 h后对大弹涂鱼的急性毒性效应.结果 显示,随着污染浓度的增加,SOD、GSH-Px和GST活性呈先升高后降低的趋势,表明低浓度污染下大弹涂鱼鳃和肝脏酶活性被激活,高浓度下污染酶活性则受抑制;大弹涂鱼鳃中SOD、CAT、GST酶活性最大诱导倍数均高于肝脏,可见大弹涂鱼鳃对原油更敏感;结合不同组织抗氧化酶活性差异显著性分析发现,大弹涂鱼鳃中SOD和GST对原油污染敏感度更高,更适合作为监测海洋原油污染的有效生物标志物.

通过对岙山岛西南侧附近海域的水文调查,分析了该调查海域潮汐潮流特征,结果表明:调查海域潮汐类型为规则半日潮;潮差较大,临时潮位站平均涨潮历时低于平均落潮历时.潮流类型为不规则半日浅海潮流,潮流运动形式以旋转流为主;流速相对较小,落潮流速大于涨潮流速;涨潮流向集中在西北偏西至北之间,落潮流向集中在东南至南之间.

“Curriculum ideology and politics" is a revolution in the ethos of education in colleges and universities. Teachers change from simple knowledge educator to leaders of socialism core value, from teaching to education and from specialists to everyone. The full exploit to the ideological and political elements of the curriculum, the full use of the main channel of classroom teaching, and taking the curriculum as the carrier to do a good job of teaching and educating people. Oceanography course contains rich ideological and political elements, and is the most suitable course for ideological and political education, and the most expressive course. Through diversified ways of integration, the organic integration of marine science ideological and political elements in classroom teaching plays a very important role in cultivating marine talents.

An electrode switching device (ESD) is one of the most important components of electrical resistivity tomography (ERT). It is a ligament and relay between a testing circuit and testing electrodes. Existing ESD uses a plane structure to realize the interconnection between ports and testing electrodes. Taking Wenner testing as an example, each electrode needs four additional switches. In this report, a new hardware saving ESD (HESD) is made with a hierarchical structure for a single-channel distributed ERT. HESD has two-layered switches to realize the conversion process. The first layer of 16 switches can realize four pairs of unrepeated connection between four ports—AMNB and four Lines—L1–L4. The second layer establishes the non-overlapping joints between four lines—L1–L4 and four testing electrodes. Each electrode only needs one switch for an 1D test, which has been wildly used in soil science, ocean probing, and contaminated surveys, and an odd number layer test. With the newly designed HESD, three fourths of the cost of hardware (switch) was saved compared with the conventional ESD. In addition, with two more switches, HESD was able to complete a 2D survey. The new two-layer HESD saves hardware costs and shows advantages in maintenance, system tests, and miniaturization, especially when many electrodes are required in an ERT system, which is very common in practice.

With the development of marine oil industry, oil spill accidents will inevitably occur, further polluting the intertidal zone and causing biological poisoning. The muddy intertidal zone and Boleophthalmus pectinirostris were selected as the research objects to conduct indoor acute exposure experiments within 48 h of crude oil pollution. Statistical analysis was used to reveal the activity changes of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione S-transferase (GST) in the gills and liver of mudskipper. Then, integrated biomarker response (IBR) indicators were established to comprehensively evaluate the biological toxicity. The results showed that the activities of SOD, CAT and GST in livers were higher than those in gills, and the maximum induction multipliers of SOD, CAT and GPx in livers appeared earlier than those in gills. Both SOD and GPx activities were induced at low pollutant concentrations and inhibited at high pollutant concentrations. For the dose-effect, the change trends of CAT and SOD were roughly inversed. There was substrate competition between GPx and CAT, with opposite trends over time. The activating mechanism of GST was similar to that of GPx, and the activation time was earlier than that of GPx. In terms of dose-effect trends, the IBR showed that the antioxidant enzymes activities in biological tissues were induced by low and inhibited by high pollutant concentrations. Overall, SOD and GPx in gills and CAT and GST in livers of the mudskippers were suitable as representative markers to comprehensively analyze and evaluate the biotoxicity effects of oil pollution in the intertidal zone. The star plots and IBR values obtained after data standardization were consistent with the enzyme activity differences, which can be used as valid supplementary indexes for biotoxicity evaluation. These research findings provide theoretical support for early indicators of biological toxicity after crude oil pollution in intertidal zones.

通过自制三维有机玻璃水槽建立非均质土层,设立浅层和内部两个泄漏点,模拟流动相原油在含水土层中的运移及水位波动条件下的重分布过程,并利用自制高密度电极排及电法仪揭示相应的电阻率响应特征.结果表明:原油在土壤中运移受泄漏源位置、泄漏量及土层结构的影响.同一土层内部泄漏点横向扩散较垂向明显,浅层泄漏点为四周扩散,泄漏量越大污染范围越宽,土层渗透性越高污染深度越深.原油泄漏后存在高阻和低阻异常2种情况,土层结构简单且含油率较高时高阻异常明显;土层组分较复杂尤其是盐分和粘土矿物含量较高,或含水率和含油率较低时,易出现低阻异常.水位升高后土层整体电阻率降低,原油向污染区中心集中;水位下降后电阻率升高,原油向四周分散,水位波动使原油进一步弥散.受内部泄漏点影响,垂向深度上离泄漏点越近(0.08m)污染越重,除此之外泄漏点下部(0.15m)原油含量高于上部(0.04m),显示内部泄漏点原油下移较上移明显.

An experimentally induced three-dimensional petroleum seepage flume was used to investigate its migration in heterogeneous soil layers and a method for monitoring resistivity was adopted, under conditions of fluctuating water levels and rainfall. The corresponding mechanisms were then analyzed based on the resistivity characteristics and combined with three-dimensional inversion images. Finally, physical and chemical property analysis was conducted to verify the results of resistivity monitoring. The results demonstrated that: (1) In the process of natural oil leakage, the variation of soil resistivity presents a concave shape in the resistivity profile. Thus, oil migration exhibited the following patterns. At first, circular migration front was dominant in a vertical direction. Subsequently, after vertical migration was impeded, lateral migration was dominant. As the crude oil gradually accumulated, the migration front broke through the limitation of lithologic interface and continued vertically. (2) By comparing the two resistivity monitoring methods, namely the Wenner and Pole-pole methods, it was demonstrated that the inversion resistivity measured by Wenner method was closer to the true resistivity, and the resistivity variations were more distinguishable. (3) The resistivity inversion profile demonstrated that the low resistivity anomaly of the crude oil leakage area was related to the low water content of the soil layer in the test area. (4) Fluctuations in water level increased the diffusion range of crude oil beyond the original pollution source area, especially horizontally. (5) Percolation of rainfall caused the water level to rise, and the crude oil was evenly distributed in the soil layers above the capillary zone. (6) Through sample analysis and verification, it was demonstrated that the resistivity method can accurately and intuitively present the characteristics of crude oil migration. These results provide theoretical support for the rapid determination of the migration range and characteristics of crude oil in heterogeneous soil layers.

生物标志物(Biomarkers)是指生物与环境因子相互作用而使生物体发生各种变化的指标或标志物,将生物标志物应用于海洋污染评价可以为海洋环境生态毒理学调查提供有效的证据.文章详述了国内外几种常见的单一类型和综合类型生物标志物评价方法在海洋石油污染监测中的应用与研究现状,概述其检测方法和意义,并指出将生物标志物应用于海洋石油污染领域可以进行早期预警,从而为海洋环境保护提供有力的科学保障.

黄河水下三角洲位于半封闭的渤海内部,海底沉积物中重金属Cu污染严重,且该区域多发风暴潮,引起沉积物再悬浮甚至液化,导致沉积物中重金属Cu重新释放进入海水中.本研究以黄河口粉质土作为底床,采用室内波浪水槽试验模拟重金属Cu在不同水动力条件下,通过静态扩散、底床未液化状态下再悬浮以及底床液化状态下再悬浮3种方式进入上覆水体的释放过程.结果表明:上覆水体中重金属Cu的浓度分布与悬浮泥沙浓度分布密切相关,呈现出一致的变化规律;沉积物液化会明显促进重金属Cu向上覆水体中释放,底床液化再悬浮阶段上覆水体中溶解态Cu的浓度为静态扩散阶段的18倍,为底床非液化再悬浮阶段的11倍;此外,底床液化会导致沉积物中重金属Cu向深处扩散,扩散深度约为沉积物液化深度的一半.

为研究原油泄漏后在非均质土层中的重分布过程及影响因素,建立3种不同组合的非均质土层物理模型(编号分别为L-a、L-b、L-c)进行原油泄漏后重分布过程的室内模拟,分别代表局部非渗透性透镜体(浅层泄漏)、大面积弱渗透性粉质亚黏土(内部泄漏)和土层界面(浅层泄漏)存在条件.待原油重力渗透稳定后分别进行升降水位和降水的模拟试验,由PET聚酯膜绘制、CCD相机拍摄和基于CMYK的灰度分析等图像采集和分析法获得平面运移分布图、纵剖面灰度变化图,采用风干法和紫外分光光度法获得采样点含水率和含油率对比图,分析原油泄漏后在非均质土层中的运移规律.结果表明:①在水位波动下,局部非渗透性透镜体和大面积粉质亚黏土弱透水层可有效截获原油,使原油在其左右及上侧大量聚集;3组试验中原油的重分布过程以垂向运移为主,但在粗-细界面和细-粗界面会因油水驱替和毛细压力导致其部分横向运移.②模拟降水时,受到淋滤和水位波动的综合效应,原油油聚区不能在短时间内随水位线移动,体现其滞后性;在模拟降水结束后油聚区大量分布于水位线位置和细-粗界面处;降水对土壤中的原油具一定稀释作用.③L-a和L-c组表层泄漏的原油分布面积(分别为800、538 cm2)较大,采样点含油率极差(分别为6.23％、6.80％)较大;而L-b组内部泄漏的原油分布面积(235 cm2)较小,采样点含油率极差(2.99％)较小.研究显示,地下水位波动及降水对非均质土层中原油的周期性聚集和释放有一定影响,尤其是局部非渗透性透镜体、大面积弱渗透性粉质亚黏土及岩性界面存在土层中影响更大.

原油作为主要能源之一对现代社会的重要作用不言而喻,但其所带来的污染危害同样不容忽视.通过自制的有机玻璃水槽,建立模型模拟自然地层的非均质性,模拟了原油在沿海土-水系统中的运移过程,探讨了局部非渗透性透镜体、底部隔水层、土壤初始含水率、土壤质地、岩性突变界面对原油在砂土中运移速度和路径的影响.结果表明,局部非渗透性透镜体和底部隔水层对原油的运移具有阻碍作用,会改变其运动速度和路径.在一定范围内,土壤初始含水率越高,原油的侧向运移速率和垂向运移速率越大(模拟成层性土层中原油垂向运移速率随含水率增大,由0.43 cm·min-1增大到1.00 cm·min-1,在低含水率区域原油侧向运移速率分别为0.08 cm· min-1(粗-细界面)和0.10 cm· min-1(细-粗界面),而在含水率较高的区域则为0.14 cm· min-1),而过高的含水率又会阻碍原油的运移.土壤孔隙越大,垂向运移越快,侧向运移越慢,反之,垂向运移越慢,侧向运移越快(模拟成层性土层中,原油在粗砂中的垂向平均运移速率为0.54 cm·min-1,而在细砂中仅为0.33 cm·min-1,自然泄漏时原油在粗砂中的最大扩散范围为9.10 cm,在细砂中为12.50 cm).原油在土壤中运移遇到岩性突变界面时,会产生聚集效应,在聚集处产生侧向运移,试验中在粗-细界面扩散宽度为6.70 cm,在细-粗界面扩散宽度为29.00 cm.

柴油在现代能源中占有重要地位,但其泄漏后对含水土层的污染不容忽视.通过自制物理模型,模拟了柴油在非均质土层的运移和重分布过程,最终对土样进行化学分析,测定代表性点位的含油率和含水率.分析了土壤质地及土质界面对柴油运移范围和速度的影响,水位升降及降雨对柴油在非均质土层中重分布的影响.结果表明:柴油垂向运移速度与土粒孔隙成正比,横向运移范围与土粒孔隙成反比;当柴油运移遇到土质界面时,不会立即向下迁移,而是先在界面处聚集,并在界面处侧向运移,扩大了污染面积;随着水位上升,部分柴油向上迁移,并被土粒吸附扩大污染面积;随着水位下降,柴油下移,污染区域进一步扩大;降雨淋滤及混合稀释作用使污染物分布更均匀.成果可为柴油污染土壤后的治理与修复提供理论支持,具有重要的实际应用价值.