常见重金属在翅碱蓬(Suaeda heteroptera)根际沉积物系统季节迁移变化

应用原子吸收光谱法(AAS)和电感耦合等离子体原子发射光谱法(ICP-AES)对翅碱蓬-根际沉积物系统常见重金属(Cu、Pb、Zn和Cd)总量和不同化学形态含量进行了季节跟踪测定。结果表明,系统中Cu、Zn、Pb和Cd环境化学行为呈现显著季节变化。从化学形态上看,根际沉积物中Cu和Pb在生理周期内均以残渣态为主,有机结合态在夏季和秋季达较高值。Zn在生理周期内均以交换态为主且随季节变化明显,碳酸结合态和铁锰结合态随季节变化不明显。Cd以残渣态为主,交换态在春季达最高。从总量上看,根际沉积物中的Cu、Zn、Pb的总量在夏季和秋季具有较高值。从系统迁移情况看,植物对Cu和Pb吸收量均为冬季春季秋季夏季,且大部分限制于地下;其体内分布除秋季Pb为根叶茎外,其它时期均为根茎叶。Zn吸收量为秋季夏季冬季春季,且绝大部分被吸收至地上。Zn吸收和分布取决于根际沉积物生物有效含量;总之,春季植物体重金属向根际沉积物迁移。夏季和秋季,Cu、Pb和Cd由根际沉积物向植物体迁移变化并不明显,而Zn正好相反。4种元素在冬季均为根际沉积物向植物体内迁移。     

上海滨岸潮滩根际重金属含量季节变化及形态分布

用Zeeman－5000型原子吸收分光光度计火焰法测定了上海滨岸潮滩沉积物中Cu、Pb、Fe、Mn、Zn、Cr的总量及其5种地球化学形态含量，发现根际沉积物中的重金属含量一般低于表层沉积物，但在重金属含量水平上，均为Fe＞＞Mn＞Zn＞Cu，Pb，Cr；单因子方差分析表明重金属在根限沉积物中存在显著的季节变化（p＜0.05＝，Cu、Pb、Fe、Mn、Zn、Cr在高潮滩芦苇根限沉积物中的含量均在夏、秋季出现最低值或次低值，在中潮滩海三棱Biao草根际沉积物中的季节含量随采样地点不同而变化，但与同一地点表层沉积物中的含量相关性很好，除Cr（r＝0．18）外，相关系数（r）分别达到0．77、0．74、0．65、0．84、0．77；Cu、Fe、Zn、Cr在沉积物中均以残渣态含量为主，Pb、Mn的碳酸盐结合态含量较高，秋季各重金属元素的碳酸盐结合态与铁锰氧化物结合态之间发生形态上的迁移与转化。     

海三菱藨草(Scirpus mariqueter)根际沉积物中重金属生物有效性的影响因素

采用野外连续调查和实验分析方法，连续3年研究了海三菱藨草根际沉积物重金属（Cu、Zn、Pb和Cd）生物有效性的主要影响因素（生长季节、pH、P、Eh和DO等）。结果表明，植物不同生长季节的变化影响根际沉积物生物有效性的季节变化。具体表现为：Cu和Pb均在春、夏季可交换态含量较高，生物有效性较高，而秋、冬季可交换态较低，生物有效性较低，但碳酸盐结合态和铁锰氧化态二者之和也比较高，具有一定的潜在生物有效性；Zn在任何季节的可交换态比例均不高，以有机结合态和残渣态的形态为主，生物有效性较低；Cd一般以残渣态为主，基本不具有生物有效性。pH值下降，春、夏季可交换态和铁锰氧化物结合态增加，而有机结合态和碳酸盐结合态减少，提高了生物有效性，而秋、冬季正好相反；磷对重金属生物有效具有直接影响的为无机磷，春、夏季随着无机磷的减少，pH值下降，提高了生物有效性。春、夏季根际Eh和溶解氧含量增加，降低了其生物有效性。     

海三棱藨草(Scirpus mariqueter)根系低分子量有机酸对根际沉积物重金属生物有效性的影响

应用等离子光谱仪(ICP)与高效液相色谱仪(HPLC)分别对海三棱藨草根际沉积物中重金属(Cu、Pb、Zn和Cd)不同化学形态含量和植物根系分泌物中常见低分子量有机酸进行了季节跟踪测定,分析了有机酸(柠檬酸、草酸、酒石酸、苹果酸、甲酸和乳酸)含量与重金属化学形态(可交换态、碳酸盐结合态、铁锰氧化物结合态、有机结合态和残渣态)的季节相关性。结果表明,柠檬酸、草酸和苹果酸含量与Cu和Pb的除残渣态外的其它4种形态含量呈正相关性,表明其能提高Cu和Pb生物有效性,与Zn的所有形态含量呈负相关性,降低了生物有效性;酒石酸、甲酸和乳酸含量与Cu和Pb的可交换态含量呈负相关性,而与其它形态含量相关性不明显,降低了生物有效性。与Zn的除残渣态外的其它4种形态含量呈正相关性,提高其生物有效性。而上述所有有机酸与Cd的各种化学形态相关性不明显。表明其对Cd的生物有效性影响不大。     

海水养殖池沉积物中重金属形态和生物酶活性的关系研究

以连云港市对虾养殖池表层沉积物为研究对象,采用Tessier连续萃取法,研究了表层沉积物中重金属(Cu、Zn、Pb、Cd、Cr、As、Mn)的赋存形态和酶(脲酶、碱性磷酸酶、过氧化氢酶、转化酶)活性的相关性。结果表明,重金属Cu和Zn以有机-硫化物结合态为主要的赋存形态,Pb以铁锰氧化物态为主要的赋存形态,Cd以可交换态(平均33.47%)和碳酸盐结合态(平均31.16%)为主要存在形态,Cr和As主要以残渣态存在,Mn的铁锰氧化物态比例最高。脲酶的活性范围为0.45—8.96mg/(g·24h),碱性磷酸酶活性范围为2.45—6.69mg/(g·24h),过氧化氢酶活性范围为0.14—2.36m L/(g·min),转化酶活性范围为0.45—10.45mg/(g·24h)。脲酶活性与Cd、As的可交换态、Cd的碳酸盐结合态、Cu、As的铁锰氧化物态、Zn、Pb、Cd、Mn的有机硫化物态之间显著相关;碱性磷酸酶活性与Zn、Cd的铁锰氧化物态显著相关;过氧化氢酶活性与Cd的可交换态、碳酸盐结合态及残渣态、Cu、Cd、As的铁锰氧化物态、Zn、Pb、Cd、Mn的有机硫结合态之间显著相关;转化酶活性与Cu、Cd、As的可交换态、Cd的碳酸盐结合态、Cu、Cd、As的铁锰氧化物态、Zn、Pb、Cd、Mn的有机硫化物态、Cd、As的残渣态之间显著相关。酶活性可以用来指示海水养殖池沉积物中重金属的形态转化过程。     

连云港临洪河口水体中重金属的化学形态与分布特征研究

对连云港海域临洪河口水体中重金属元素Cu,Zn,Pb,Cd的主要存在形态及悬浮颗粒态重金属元素的赋存形态进行了分析。结果表明:悬浮态重金属Cu,Zn,Pb,Cd的含量在调查海域内空间分布基本均衡,Zn、Cu、Cd主要以溶解态形式存在,而Pb则主要以颗粒态形式存在。对悬浮态重金属元素的赋存形态分析表明,Cu主要富集在有机-硫化物态、Zn主要富集在残渣态、Pb主要富集在铁锰氧化物态和碳酸盐结合态、Cd主要富集在可交换态和碳酸盐结合态。     

基于生物可利用性评估城市道路沉积物重金属生态风险

城市道路沉积物重金属风险评价是表征城市环境质量的有效途径。采用重金属化学形态和生物可利用性来评估其生态风险更合理,越来越受到人们的关注。本文采集山东省青岛市崂山区10条次干道沉积物样品,分析不同粒径沉积物中Zn、Cd、Cu、Pb的含量、化学形态和生物可利用性,采用地累积指数(Igeo)和改进的生态风险指数(RIm)评价细粒径(小于75μm)沉积物中重金属污染水平和生态风险。结果表明:(1)沉积物粒径越小,重金属含量则越多。当粒径小于75μm时,Zn、Cd、Cu和Pb平均含量分别为山东省土壤元素背景值的10.63、6.07、3.39、2.70倍。(2)随粒径的减小,生物可利用性增大。小于75μm粒径的Zn、Cd、Cu和Pb的生物可利用态百分比为74%、78%、66%和55%。(3)评价结果显示,Zn、Cd、Cu和Pb的值分别为2.83、2.01、2.22和2.05,结果均为偏重度污染。(4)评价结果为较高生态风险,其中Cd属于极高风险,Cu和Pb属于中等风险,Zn属于低风险,Cd对的贡献高达75%。以重金属污染水平、迁移率、生物可利用性和生态风险为评价依据,认为Zn、Cd、Cu、Pb的风险均较大。该研究可为青岛市道路重金属污染防控提供指导。     

苏北王港近岸表层沉积物元素地球化学特征与环境意义

对王港河河道及河口附近潮滩典型地貌部位表层沉积物粒度、常量和微量元素进行分析,结果表明：潮滩和河道近岸沉积物为粘土质粉砂,粒度分布频率曲线在平均高潮线附近的沉积物为双峰态外,其余为单峰态。互花米草滩沉积物中常量和微量元素(Al2O3,TiO2,CaO,Fe2O3,K2O,MgO,MnO和Cu,Rb,Pb,As,Zn)均表现出相对富积的特征,盐蒿滩次之,反映海岸带互花米草在削浪促淤的过程中,对重金属污染有效吸附作用比盐蒿潮滩滩大。SiO2化学性质比较稳定,对沉积地貌动力的响应比较显著,近岸高潮线附近和河道中主洪道沉积物SiO2含量明显偏高。河闸上游河道沉积物中烧失量、磷(P2O5)、硫(稳定态SO3)的含量最高,反映流域营养盐在水闸以上河段沉积物中富积,重金属元素Rb,Pb,As,Ba在河道沉积物中与地壳风度相比表现为富集。王港附近潮滩表层沉积物物质组成不仅与王港河、黄河及长江的物质来源有关,而且与古潮滩沉积再搬运、再沉积以及人类围垦及排放污染活动有关。As,S是该区主要的污染元素。     

黄、东海表层沉积物重金属赋存形态及风险评价

利用Teissier 5步连续提取法分析了黄、东海6个表层沉积物样品中重金属Zn、Pb、Ni、V、Fe和Mn的赋存形态,并基于富集因子评价法、地质累积指数评价法和酸提取态比重风险评价法对6种重金属的污染现状和潜在生态风险进行了初步评价。各重金属的含量分布依次为:FeMnZnVNiPb。Ni、Zn、V和Fe两两之间均呈现很好的正相关,表明这些元素污染具有同源性。赋存形态分析表明,V、Fe、Zn和Ni主要以残渣态存在,Pb和Mn在可提取态和残渣态比例相当。铁锰氧化物结合态和碳酸盐结合态是非残渣态Pb和Mn的主要存在形式。富集因子评价法和地质累积指数评价法结果显示,Pb、V、Fe和Mn主要受自然来源影响,未受到人类活动的影响。Ni和Zn受到轻微人类活动影响。酸提取态比重风险评价结果显示,Pb和Mn风险评价为中风险,易从沉积物重新释放进入水体形成二次污染。     

长江口及其邻近海域表层沉积物中部分金属元素赋存形态研究

2014年6月在长江口及其邻近海域采集了表层沉积物样品,用连续提取法对Cr、Co、Ni、Cu、Zn、Al、Mn和Fe金属元素的赋存形态进行分离,即分作可交换态(EXC)、碳酸盐结合态(CARB)、铁锰氧化物结合态(ERO)、有机结合态(OSM)和残渣态(RES)并测定了含量。结果表明,长江口及其邻近海域表层沉积物中的Cr主要赋存在OSM态中,Mn主要赋存在CARB态中,Ni在OSM态和ERO态含量相当,Co、Cu、Zn、Al和Fe元素主要赋存在ERO态中。长江口及其邻近海域D断面表层沉积物中Cr、Co、Ni、Cu、Zn、Al、Mn和Fe元素的非残渣态含量随着离岸距离的增加而逐渐降低。ERO态金属元素随着沉积物中铁锰水合氧化物的含量的升高而增加,且ERO-Cr、Co、Ni、Cu、Zn、Al与铁锰水合氧化物含量之间有较好的相关性,说明这些金属元素受到铁锰水合氧化物的影响。各金属元素非残渣态总量与ERO-Fe含量之间相关性也较好,说明各元素非残渣态受控于其各自主要的赋存形态。     

Assessing the Validity of Seismo-Acoustic Predictor Equations for Obtaining Seabed and Sub-Surface Sediment Physical Properties

The interdependence between the seismo-acoustic properties of a marine sediment and its geotechnical/physical parameters has been known for many years, and it has been postulated that this should allow the extraction of geotechnical information from seismic data. Though in the literature many correlations have been published for the surficial layer, there is a lack of information for greater sediment depths. In this article, a desktop study on a synthetic seafloor model illustrates how the application of published near-surface prediction equations to subsurface sediments (up to several tens of meters burial depth) can lead to spurious predictions. To test this further, acoustic and geotechnical properties were measured on a number of sediment core samples, some of which were subjected to loading in acoustically-equipped consolidation cells (oedometers) to simulate greater burial depth conditions. For low effective pressures (representing small burial depths extending to around 10 meters subsurface), the general applicability of established relationships was confirmed: the prediction of porosity, bulk density, and mean grain size from acoustic velocity and impedance appears generally possible for the investigated sedimentary environments. As effective pressure increases through, the observed relationships deviate more and more from the established ones for the near-surface area. For the samples tested in this study, in some instances increasing pressure even resulted in decreasing velocities. There are several possible explanations for this abnormal behavior, including the presence of gas, overconsolidation, or bimodal grain size distribution. The results indicate that an appropriate depth correction must be introduced into the published prediction equations in order to obtain reliable estimates of physical sediment properties for greater subsurface depths.     

海上大直径钢管桩打桩过程中桩周土强度弱化研究

海上大直径钢管桩打桩过程中,桩周土体受到强烈扰动而发生强度弱化,掌握桩周土体强度弱化规律对于准确预测打桩过程、保证工程安全具有重要意义。为研究土体强度弱化规律,开展了环剪试验模拟打桩对桩周土体的扰动,测试土体强度随剪切速率的变化规律,建立了描述土体强度弱化规律的拟合公式,引入到打桩分析软件中。研究结果表明：土体的强度折减程度不仅与土体本身的性质有关还受到土体的埋深和剪切速率的影响,埋深越深土体强度折减程度越低,剪切速率越高土体强度折减越高,在打桩分析中可采用这里推荐的线性折减方法来模拟不同深度处土体强度的折减规律。     

Interannual Sea Level Variations and Annual Tides in the Northwestern Pacific

Specific properties of the interannual sea level variations and annual tides in the Northwestern Pacific were studied. Several tide stations were monitored. The monthly mean sea level for the year of 1995 was analyzed at each tide station. A seismic event in 1995, some tectonic activity around the subject area, and the Kuroshio (the oceanic western boundary current) may possibly contaminate results which would have occurred from the astronomical annual tide alone.     

Flow Cytometric Analysis of Coastal Lagoon Bacterioplankton and Picophytoplankton: Fixation and Storage Effects

The effect of different fixation and storage protocols on the flow cytometric (FCM) simultaneous analysis of bacterioplankton and phytoplankton in coastal seawater samples (Mediterranean coastal lagoons) was investigated. FCM measurements (cell number, fluorescence and scatter characteristics) were obtained through DAPI staining. Three fixatives [glutaraldehyde (GA), formaldehyde (FA) and paraformaldehyde (PFA)] and two storage (3 months duration) methods (5 °C and −196 °C) were tested. Two dominant populations were detected in studied samples: bacteria and eukaryotic picophytoplankton. Adding fixatives (2% final concentration) appears necessary to obtain FCM exhaustive counts of all the bacteria and phytoplanktonic cells. This was related to the permeation effect of fixatives which allowed a better DAPI staining of the cells. Maximum fluorescence, i.e. optimal staining of the cells was obtained with FA or PFA, and significant lower fluorescences with GA. Fixed samples stored at 5 °C induced rapid cell loss. Only storage in liquid nitrogen of samples fixed with FA or PFA, allows mid-term (≥4 months) preservation of bacteria or picophytoplankton cell numbers, and limited evolution of DAPI-induced fluorescence and scatter characteristics.     

INFORMATION FOR AUTHORS

<正>Acta Oceanologica Sinica(AOS)is a comprehensive academic journal edited by the Editorial Committee of Acta Oceanologica Sinica and is designed to provide a forum for important research papers of the marine scientific community which reflect the information on a worldwide basis.The journal publishes scholarly papers on marine science and technology,including physics,chemistry,biology,     

Phylogenetic diversity and phenotypic characterization of cultivable bacterioplankton isolated from polar oceans

A set of 27 marine planktonic bacteria isolated from the polar regions was characterized by 16S rDNA sequencing and physiological and biochemical testing. More than half of these bacteria were positive for caseinase, gelatinase and 13-glucosidase, and could utilize glucose, maltose or malic acid as carbon source for cell growth. Twelve isolates expressed nitrate reduction activities. Except for one antarctic isolate BSwlO175 belonging to Actinobacteria phylum, these isolates were classified as γ-Proteobacteria, suggesting that γ-Proteobacteria dominated in cultivable marine bacterioplankton at both poles. Genus Pseudoalteromonas was the predominant group in the Chukchi Sea and the Bering Sea, and genus ShewaneUa dominated in cultivable bacterioplankton in the Prydz Bay. With sequence similarities above 97%, genus Psychrobacter was found at both poles. These 27 isolates were psychrotolerant, and significant 16S rDNA sequence similarities were found not only between arctic and antarctic marine bacteria （ 〉 99% ）, but also between polar marine bacteria and bacteria from other aquatic environments （ ≥ 98.8% ）, including temperate ocean, deep sea, pond and lake, suggesting that in the polar oceans less temperature-sensitive bacteria may be cosmopolitan and have a bipolar, even global, distribution at the species level.     

Net Sand Transport Direction in a Tidal Inlet, using Foraminiferal Tests as Natural Tracers

The relationship between the flux of exotic benthic foraminiferal tests (i.e. tests which are supplied from open-sea sources alone) in a tidal inlet and that of bulk sediment was analysed, which can be expressed as two first-order linear equations. According to this relationship, in order to determine net sediment transport directions in the entrance, the test concentration in surficial sediments of the tidal basin can be compared against a ‘ critical level ’. The critical level is determined for the conditions that no net transport of bulk sediment is present within the entrance. If the observed concentration (averaged over the tidal basin) is higher than the simulated critical level, then the net sediment transport is directed to landward. This method is applied to the analysis of net sand transport at Christchurch Harbour, a tidal inlet system located in southern England. In this investigation, concentrations of exotic foraminiferal tests in the surficial sediments of the tidal basin and ebb tidal delta area were obtained from the analysis of sea-bed sediment samples. A series of probable critical levels were calculated based upon the data sets with regard to: (1) sediment discharge from the rivers; (2) magnitude of sediment discharge within the entrance during the ebb; (3) the test concentration outside the harbour; (4) the thickness of the moving layer; and (5) two parameters associated with dispersive processes. The results show that the concentration in the tidal basin sediment is higher than a number of simulated critical concentrations for representative cases. Consequently, the high level of the concentration of exotic benthic foraminiferal tests within the harbour should be explained as a result of landward net transport of sands within the entrance.