Grain Size Partitioning of Mercury in Sediments of the Middle Odra River (Germany/Poland)

The Odra River is the second largest river in Poland, running from Czech Republic through a large part of Poland before entering the Baltic Sea. For the last century its catchment area has been heavily polluted by anthropogenic emissions. The aim of this study is to determine the distribution of mercury in different grain size fractions of surface sediments from the middle course of the Odra River. Mercury concentrations were determined in bulk sediments of different grain size fractions using the cold vapor atomic fluorescence spectrometry method. The total mercury concentration in bulk sediments varied from 0.051 to 1.31 mg/kg dry weight. The concentration of total mercury was determined in the grain size fractions <0.2, 0.2–0.5, 0.5–1.0, 1.0–2.0 and >2.0 mm to be (in mg/kg d.w.): 0.118–2.99, 0.033–0.99, 0.034–1.17, 0.035–1.97 and 0.017–3.65, respectively. Gradual decrease in the mercury concentration with increasing grain size from fine to coarse fraction has been observed only for sediments taken from the river bed. Although, no similar gradual decrease in the mercury concentrations has been observed for sediments from the river banks, finer sediments (<0.2 mm) still tend to show higher concentrations of mercury.     

察尔汗盐湖沙漠沙丘沉积物粒度特征分析

在对柴达木盆地沙漠地区两次野外实地调查的基础上,选取察尔汗盐湖沙漠盛行风向沿线的线形沙丘和新月形沙丘沉积物样品进行了粒度特征分析。结果表明,研究区沙区沙粒度组成以细沙和中沙占优,粉沙和黏土含量明显,粒度变化遵循沿盛行风向粒径变细的规律;粒度参数特征表现出沉积物平均粒径较国内其他沙漠偏粗,分选较差,呈正偏-近对称形分布,线形沙丘成熟度比新月形沙丘偏高;沉积物累计概率曲线特征指示研究区沙区沙的沉积环境以跃移搬运为主,存在明显的悬移搬运和微弱的滚动搬运。     

Determination of Elemental Sulfur in the Presence of Anaerobic Sediments by Extraction Procedure Using High-Performance Liquid Chromatography

Elemental sulfur is the most commonly found form of sulfur in anaerobic sediments. Accurate determination of elemental sulfur is the key step to know physical chemistry and biogeochemical processes in the sediments. A novel method was developed for the analysis of elemental sulfur using high-performance liquid chromatography (HPLC) with a C18 column. The procedure of determination of elemental sulfur concentrations from 0.1 to 100 mg/g (on a basis of the dry weight of sediment) is based on the direct injection of acetone extracts of sediments into a chromatographic column. The linearity range of 20–110 mg/L showed an excellent linearity of response (r = 0.999). The limit of detection and limit of quantitation for elemental sulfur were 9.41 and 4.18 μg/L, and converted sulfur mass per sediment mass was 1.88 × 10^?2 and 8.36 × 10^?3 μg/kg. Besides, a repetitive experiment (ten times) was carried out and the average chromatographic peak area was 141.47 mg L^?1. The sulfur concentration in the solution used for the determination of standard deviation and relative standard deviation was 1.02 and 0.727%, respectively. The average recovery ranges between 98 and 100%. The quantitation of elemental sulfur in sediment samples from anaerobic digestion reactor is obvious, and the average concentration of elemental sulfur on the basis of the dry weight of the sediment is 5.24 mg/g. The method was sensitive and exhibited good signal-to-noise ratio, as well as linear responses over a wide concentration range.     

黔西南喀斯特洞穴沉积物粒度特征分析

通过采集贵州北盘江峡谷石漠化研究区内唐家大洞地下洞穴沉积物土壤和基岩样品,利用MASTERSIZER 2000激光粒度分析仪对土壤样品进行测定,按照乌顿-温德氏粒级标准,利用Folk-Ward公式计算出平均粒径、标准偏差、偏度和峰度等土壤粒径参数,对5个基岩样品进行浸泡溶蚀试验,计算出溶蚀率(R)及溶蚀速率(R_v)。结果表明,北盘江喀斯特地表侵蚀及溶蚀较严重,洞穴向地层裂隙方向以纵向发育为主;洞穴地下河道沉积物分选性较差,土壤样品粒径以黏粒、粉砂、细砂3个粒级为主;洞穴沉积物粒径变化范围不大且分选性较差,沉积物粒径相对较细且分布特征基本一致;根据沉积物表层HJ-01与下层HJ-02至HJ-05粒径分布特征,沉积过程中可能存在降雨量大小两种情况且二者相互交替具有循环性,主要受水文环境与碳酸盐岩溶蚀程度影响。     

重庆市玉溪遗址古洪积地层的粒度特征

通过玉溪遗址T0403探方11个古洪积层粒度参数分析,发现该遗址古洪积层的特征是:①遗址古洪积层粒度频率曲线为单峰正偏,分选差,概率累积曲线为典型三段式,且推移质组分>40%;②洪积层角闪石、磷灰石等不稳定矿物含量高于现代洪水层,表明古洪积层主要为近源沉积。联系到古洪积层形成期(6.3~7.5 ka B.P.)属于全新世大暖期的高温波动期,干湿波动是造成玉溪地区洪水频发的主要原因,同时根据遗址文化地层出土的器物判断,古洪积层沉积粒度特征变化与新石器人类的农业生产活动有关。     

博斯腾湖湖岸沉积物磁化率和粒度特征分析

选取博斯腾湖西岸剖面进行环境磁学测试,并结合粒度组分进行相关性分析。研究结果表明:磁化率随深度变化的变化呈上升再下降趋势,并出现波动—平缓—波动的变化过程。随深度变化,影响磁性参数的主导因素不同。表层土壤主要受生物作用影响;中间层主要受沉积源磁性矿物影响;底层湖相沉积物的磁性特点及粒度分布主要受湖泊沉积环境及水动力条件影响。在剖面湖相沉积所处时代,博斯腾湖水动力条件减弱,气候环境相对干旱,湖泊处于收缩过程中,并且在收缩过程中湖水的动力条件存在明显波动。     

Comparison of Single and Sequential Extraction Procedures for Assessing Metal Leaching from Dredged Coastal Sediments

Potential uses of dredged sediments have raised questions about leaching of contaminants from such material once transported to other locations and exposed to other environments. In order to estimate leachable, i.e. available fractions of chemical elements in such materials, a number of analytical protocols were proposed, of which none is internationally accepted as a standard procedure. As a consequence, comparability of the results obtained by different protocols in various laboratories is difficult to demonstrate. In the present study some commonly used protocols including a leaching test with (i) seawater, following the modified German Standard Method (DIN), (ii) a single extraction with 25% acetic acid, following the method proposed by the United Nations Environment Programme (UNEP), and (iii) a three-step sequential extraction, following both the original and the modified protocols of the Standards, Measurements and Testing Programme (formerly Community Bureau of Reference – BCR), were performed for assessing the availability of lead, zinc, nickel and copper leachable from dredged marine sediments. A comparison of the results obtained by the different protocols indicated that the single extraction with acetic acid is a reliable simplified technique and allows more rapid evaluations of dredged areas of coastal lagoons in the Northern Adriatic. This procedure provides information on the potentially bioavailable portion of metals.     

基于计算机视觉的粒度检测方法研究

利用计算机视觉技术进行超微粉碎物料粒度检测方法的研究。采用非线性变换对图像进行对比度增强处理，利用自动取阈值算法分割目标和背景，设计了识别算法用于去除凝聚颗粒，以得到样本真实粒度和分布。实验证明用显微图像进行粒度检测，测定分布状态直观明了，检测结果稳定，可测量0.1～150 μm颗粒粒径。     

BCR法在污染农田黑土重金属形态分布研究中的应用

通过对东北地区污染农田黑土剖面的取样调查分析，对重金属Cd、Ph、Cu、Zn在农田黑土中的污染状况及其迁移特征进行了对比研究，并就BCR（the Community Bureau of Reference）连续提取法在农田土壤重金属污染评估中的应用进行了探讨。结果表明，重金属的迁移率大小依次为：Cd〉Cu〉Pb〉Zn，Cd的酸可溶态占全量的比率高于其它重金属。Pb的酸可提取态浓度随土壤深度增加而增大，公路附近土壤中PL、Cu及城市郊区土壤中Cd、Pb和Zn的氧化物结合态含量均随土壤深度的增加而升高，已存在向下迁移的趋势。4种重金属有机结合态在采样区土壤中基本都表现为耕层高于非耕层。研究表明，应用BCR连续提取法有助于确定土壤重金属污染以及重金属向下迁移状况，借助该法可以有效、可靠地对土壤重金属污染进行评估。     

帕米尔高原东部表层沉积物粒度特征及其迁移路径

[目的]研究帕米尔高原东部表层沉积物粒度特征及来源,为提高中国西部高原地区沉积环境认知及生态环境建设提供科学依据。[方法]利用激光粒度仪对帕米尔高原东部表层沉积物粒度进行分析,并通过后向轨迹模型探讨远源风成沉降对其表层沉积物组成的影响。[结果]研究区表层沉积物以砂粒为主,表层沉积物粒径随海拔的逐渐升高而减小。初步推测表层沉积物主要为湖相沉积,远源风成沉降主要受中亚西风气流和塔克拉玛干沙漠西侧沙尘颗粒物影响。[结论]帕米尔高原东部处于生态环境脆弱区,应因地制宜制定土地利用规划,同时需防范中亚沙尘颗粒对其生态环境的影响。     

连续分级提取法研究春季巢湖沉积物中不同结合态氮的赋存特征

为研究沉积物中不同形态氮的释放能力及其生物可利用性大小,为湖泊水环境生态安全评估提供基础依据,以春季巢湖表层沉积物为例,采用连续分级提取法将氮分为游离态氮（FN）、可交换态氮（EN）、酸解态氮（HN）及残渣态氮（RN）,并研究了这4种形态的赋存特征。结果表明,沉积物中总凯氏氮含量（TKN）在1004—2285mg·kg^-1之间,各形态氮含量大小为HN〉EN〉RN〉FN,占总提取态氮比例分别为78．32％、11．50％、9．76％、0．42％。酸解氨基酸态氮是可矿化态氮最有效贡献者,多元逐步回归方法得到“最优”方程为y=0．696AAN-108．918。连续提取法测得总氮值（TSEN）比用凯氏半微量法测得总氮值（TKN）偏小,但在误差允许的范围内,TSEN可替代半微量凯氏法测得的总氮。     

1953-2010年黄土洼天然淤地坝内洪水沉积物粒度旋回特征

利用¹³⁷Cs断代技术进行沉积物的测年,结合1953年以来的降雨资料,对黄土洼天然聚湫坝淤地的水成沉积物粒度旋回特征进行了分析。结果表明,坝淤地4 m沉积物是在近百年内形成的,物源比较单一,主要为洪水沉积物;降雨是影响沉积物粒度的主要因素;淤地坝内洪水沉积物粒度以粗粉砂为主,中砂含量很少,没有粗砂;沉积物剖面具有良好的沉积层理,剖面粒度旋回至少记录了42次较大的洪水事件,不同期次洪水沉积物之间粒度变化明显,反映了该区近百年内年流域侵蚀和降水量的变化。     

伊犁河谷不同土地利用方式下土壤粒度特征

为更有效地指导伊犁河谷水土环境的可持续发展,对河谷地区不同土地利用方式下的土壤进行采样,共获得14个剖面98个土壤样品。利用EASY SIZER20测定样品粒度,依据福克—沃德公式计算中值、平均粒径、标准偏差、峰度、偏度,采用Excel,SPSS 19.0等统计软件进行作图和统计分析。结果表明:(1)不同土地利用方式下土壤粒级百分含量虽有不同,但都是以粉粒(2~50μm)、砂粒(50~2 000μm)为主。其中耕地的粉粒、砂粒百分含量均高于荒地,林地、草地的黏粒(2μm)百分含量相当。(2)不同土地利用方式下土壤粒级的变异系数表现出显著性差异。耕地中粉粒、砂粒含量的变异系数普遍大于荒地,黏粒含量的变异系数则相反。(3)不同土地利用方式下土壤粒度特征不同,耕地的平均粒径明显大于草地、荒地、林地,荒地的分选性明显优于耕地、园地。     

Assessment of Fe,Zn, Cd,Hg, and Pb in the Jordan and Yarmouk River Sediments in Relation to Their Physicochemical Properties and Sequential Extraction Characterization

Forty-six surface sediment samples taken along the beds of boththe Jordan and Yarmouk Rivers were analysed for Pb, Cd, Zn, Fe andHg by atomic absorption spectrophotometer. Extraction techniqueswere used to establish the association of the total concentrations of Pb, Cd, Zn and Fe in the sediment samples withtheir contents in the exchangeable, carbonate, Fe/Mn oxides, organic and residual fractions.In the sediments of the Jordan River the recorded heavy metalsconcentrations were as follow: 8.1 ppm for Pb, 0.63 ppm for Cd, 20.3 ppm for Zn, 6 ppm for Hg and 1265.6 ppm for Fe; whereas in the sediment of Yarmouk River were 8.4 ppm for Pb, 0.67 ppm for Cd, 26.4 ppm for Zn, 6.2 ppm for Hg and 1370 ppmfor Fe. Pb, Cd, Zn, and Fe concentrations in the sediments ofboth rivers reflect the natural background value in shale, whereas Hg is moderately enriched. I-geo (geo-accumulation index) of metals in the sediments under study indicates thatthey are uncontaminated with Pb, Zn and Fe; contaminated tomoderately contaminated with Cd; and strongly contaminated with Hg. Heavy metal content in the sediments were found to be significantly influenced by different physico-chemical parameters. The effect of these physico-chemical parameters canbe arranged in the following order: clay fraction > organicmatter fractions > carbonate fraction > silt fraction. As sequential extraction procedure shows that the total concentration of the heavy metals are largely bound to the residual phase (retained 79.5% of Pb, 38% of Cd, 54.4% of Zn and 51.6% of Fe in Jordan River Sediments; and 88.6% of Pb, 48.2% of Cd, 37.6% of Zn and 59.5% of Fe in the YarmoukRiver sediments). The following sequence of mobility are suggested: Fe > Cd > Zn > Pb in Jordan River sediments, and Fe > Zn > Cd > Pb. in Yarmouk River sediments.     

中国5种典型土壤的侵蚀泥沙粒径分布特征

通过天然降雨试验,研究我国5种典型土壤的侵蚀泥沙团粒和单粒粒径分布以及泥沙各级团粒的机械组成特征。2013—2014年汛期(6—9月),监测红壤、紫色土、黄绵土、褐土和黑土径流小区的降雨产流事件,收集侵蚀泥沙样品,利用湿筛法和吸管法测定其团粒和单粒粒径分布;同时,筛选出泥沙各级团粒样品,进一步测定其单粒粒径组成。结果表明:(1)侵蚀泥沙粒径分布是土壤质地和降雨强度综合作用的结果,团粒粒径分布更适合作为表征泥沙输移的指标;(2)5种土壤的侵蚀泥沙皆表现出粉团(0.002~0.05mm)和黏团(0.002mm)的明显富集;(3)在泥沙单粒粒径分布方面,除红壤的粉粒(0.002~0.05mm)和黏粒(0.002mm)有轻微富集外,其余4种土壤的各级单粒均无明显富集;(4)红壤侵蚀泥沙粉团(0.002~0.05mm)中的黏粒含量最多,其余4种土壤侵蚀泥沙机械组成和各级团粒的机械组成均与原土接近。     

Quality Evaluation of Sediments from 24 Tributaries of the Po River, Italy

Sediment samples from 24 tributaries of the Po River (Italy) were screened for selected trace elements (Cd, Cu, Hg, Pb, and Zn) and extractable organic compounds; a proxy for contamination by organic microcontaminants. The toxicity of sediment extracts was evaluated using a battery of biotests (Dugesia gonocephala, Paracentrotus lividus, and Tamnocephalus platyurus). Contamination by trace elements (including very high Hg pollution – 4 to 16ppm total Hg – in one sub-basin) reached potentially harmful levels only in the sediments of four tributaries; while contamination by organic microcontaminants was present in most sub-basins. Sediments from most study sites did actually show signs of anthropogenic stress and were able to elicit a toxic response. A more detailed evaluation of sediment quality in the Po River tributaries seems to be urgently needed for developing the necessary remediation strategies. Research priorities should include more thorough testing of sediment toxicity, determination of metal background levels in the various sub-basins and a more detailed identification of the organic micropollutants of possible concern.     

黄河表层沉积物中磷的分布特征及磷的生物可利用性

采用改进的七步连续提取法分别对黄河中下游流域5个不同段位表层沉积物中总磷（TP）、有机磷（OP）及各种无机磷形态进行了分析,研究并探讨了沉积物中磷的分布特征及其对河海可能产生的影响,为预测黄河乃至渤海流域的营养状况、预防及科学管理等提供理论依据。结果表明,所测黄河表层沉积物中TP含量范围为240.71-576.59μg.g^-1,以无机磷（IP）为主,占TP含量的85.73%-98.48%;OP含量占TP的1.52%-14.27%。受陆地河流和海流注入的影响,所研究沉积物样中TP、IP和OP含量的最大值均出现在靠近黄河口的渤海浅海区,其次是黄河口。IP分为6种形态磷,即交换态磷（Ex-P）、铝结合态磷（Al-P）、铁结合态磷（Fe-P）、闭蓄态磷（Obs-P）、自生钙结合磷（Ca-P）和原生碎屑磷（De-P）,其中以De-P为主,其次是Ca-P,分别占TP的52.47%-73.67%和18.32%-38.20%,Ex-P、Fe-P和Al-P含量均相对较低,Obs-P含量最低。各形态磷的空间分布均与调查区沉积物粒径有一定相关性,粒径小于0.063 mm的沉积物样中TP和IP含量均最高。Ex-P、Al-P、Fe-P、Or-P和部分Ca—P作为黄河表层沉积物中潜在的生物可利用磷,其总量至少占TP的6．09％-24．46％。     

湘江衡阳段河漫滩沉积物粒度特征与历史洪水事件

[目的]分析河漫滩沉积记录的历史时期洪水信息,揭示极端洪水事件和洪水发生规律,为防洪减灾提供指导.[方法]根据湘江河漫滩沉积剖面91个样品的粒度分析,结合AMS 14C精确测年,分析湘江衡阳段河漫滩剖面粒度特征与洪水事件.[结果]①河漫滩沉积物粒度组成以粗粉砂、粗砂、极细砂为主.粒度参数显示,剖面洪水沉积动力较强,分选...     

塔里木河干流古河道表层沉积物粒度特征及其意义

历史上塔里木河因频繁改道在干流两岸遗留了多条古河道,研究其表层沉积物粒度特征,可判断表层沉积物形成时的沉积环境与水动力条件。通过对塔里木河古河道表层沉积物系统采样,进行粒度分析发现:(1)塔里木河古河道表层沉积物优势粒级为粉沙,粒度次一级组分在干流两岸古河道间差异明显;(2)古河道表层沉积物比塔里木河洪泛平原土壤粒径细小,表明古河道晚期水动力较弱;(3)塔里木河干流南岸的部分古河道表层沉积物中,含风成沙夹层,反映了其沉积环境受风水两相作用。     

化学提取法与梯度扩散薄膜技术提取太湖沉积物中有效砷的比较

以底栖生物河蚬（Corbicula fluminea）为实验生物,外源三价砷污染太湖沉积物为研究对象,利用生物富集实验分别比较了DGT（Diffusive gradients in thin films）梯度扩散薄膜技术和化学连续提取法所测浓度与河蚬中砷的生物有效性的相关性,并分析了这两种方法的差异。实验结果显示随着沉积物中染毒的总砷浓度（9.48,14.12,19.88,26.86,35.66,46.42,54.25mg·kg^-1）增加,DGT测得砷浓度和化学提取法所测砷含量也随之增加,Pearson相关系数均在0.98以上（P〈0.01）,表明这两种技术均能很好地预测沉积物中有效砷含量。通过河蚬对三价砷的暴露实验,发现当沉积物总砷含量在35.66mg·kg^-1以下时,暴露14d和28d后河蚬体内富集的总砷含量与暴露浓度增加趋势一致。Pearson分析结果显示DGT法和化学提取法测得结果均与河蚬体内砷的富集量显著相关,因此这两种方法都可用于预测河蚬体内肉质部的总砷富集量。