Accumulation discrepancy of heavy metal and organic pollutants in three near-shore depositional environments, southeastern China

Heavy metal and organic pollutants in sediments along the coastal zone of southeastern China have been investigated. Sediment samples are retrieved from three depositional environments: coast, estuary, and tide-affected river mouth. The relative abundance of heavy metal and organic pollutants is related to their geochemical properties as well as depositional environments and anthropogenic discharge. Based on a sequential extraction method, it is revealed that anthropogenic Pb, Cr, Cu, and Cd are mainly bound to Fe–Mn oxides, suggesting that adsorption and co-precipitation of Fe–Mn oxides are in the control of their transfer processes from water column to sediment. Heavy metal bound to carbonates is also an important pool especially for Cd, Mn, and Pb. The main organic pollutants found in the study area include petroleum-related alkanes, phthalic acid ester, organic silicon, chlorophenol, phenyl ether, and amine. The accumulation of heavy metals and organics in surficial sediments has a decrease tendency from estuarine environment to coastal environment and to tide-affected river mouth.     

Spatial variations in heavy metals on tidal flats in the Yangtze Estuary,China

Surface samples are used to determine onshore-offshore variations in heavy metal concentrations on tidal flats on Chongming and Hengsha Islands in the Yangtze Estuary, China. The Mann-Whitney U-Test suggests that proximity to the estuarine turbidity maximum does not result in significantly higher metal concentrations on tidal flats. Principal Components Analysis shows that grain-size is the primary control on metal concentrations, reflecting the occurrence of salt marsh and mud and sand flats. Sediment quality is comparable to that of pristine estuaries because of dilution by high river sediment loads.     

The effect of grain size on the Cu, Pb, Ni, Cd speciation and distribution in sediments: a case study of Dongping Lake, China

This paper examines the surface sediments collected from Dongping Lake in China for speciation and distribution of toxic heavy metals (Cu, Pb, Ni, Cd) in different grain size fractions, and for the factors that need to be considered in potential hazard of metals to the environment. Four grain size fractions (<63, 63–78, 78–163 and 163–280 μm), divided in wet condition, and bulk samples less than 280 μm in diameter were analyzed for their distribution, density and appearance. A three-stage extraction procedure following the BCR protocol was used to chemically fractionate metals into “acid soluble”, “reducible”, “oxidizable” and “residual” fractions. Correlation analysis was used to analyze the datasets. The results showed that <63 μm grain size part constitutes the major proportion of the sediments, but its density is the smallest among the four grain size fractions. In general, the metal content curve against grain size presents “S” distribution, and the highest concentrations do not exist in <63 μm grain size. Appearance observation indicates that the adsorbed substance increases gradually along with the decreasing grain size. The dominant speciation of elements and the extent of pollution are responsible for the metal distribution in different grain size sediments. While studying bioavailability and mobilization of metals, it is advisable to take metal speciation, grain size distribution and density into consideration.     

Spatial distribution of heavy metals in surficial sediments from Guanabara Bay: Rio de Janeiro, Brazil

Ninety-two surface sediment samples were collected in Guanabara Bay, one of the most prominent urban bays in SE Brazil, to investigate the spatial distribution of anthropogenic pollutants. The concentrations of heavy metals, organic carbon and particle size were examined in all samples. Large spatial variations of heavy metals and particle size were observed. The highest concentrations of heavy metals were found in the muddy sediments from the north western region of the bay near the main outlets of the most polluted rivers, municipal waste drainage systems and one of the major oil refineries. Another anomalous concentration of metals was found adjacent to Rio de Janeiro Harbour. The heavy metal concentrations decrease to the northeast, due to intact rivers and the mangrove systems in this area, and to the south where the sand fraction and open-marine processes dominate. The geochemical normalization of metal data to Li or Al has also demonstrated that the anthropogenic input of heavy metals have altered the natural sediment heavy metal distribution.     

Sediment distribution characteristics and environment evolution within 100 years in western Laizhou Bay,Bohai Sea,China

This study is about the reconstruction of fluvial origins based on the grain size distribution of sediment deposits in the western Laizhou Bay, Bohai Sea, China. Thirteen sediment cores were selected to research sediment characteristics using the Sahu discriminant formula, C-M diagram, and Folk method. The results showed: (1) Bounded by the Guangli River estuary, the north sediment was affected by the water and sand flowing from the Yellow River during different periods. The south sediment came from multi-source rivers under the influence of the Xiaoqing River, Mihe River, and other coastal rivers; (2) the deposited sediments were dated by a clear historical record of the branched channel oscillation combined with the characteristics of the diversion channel, erosion, and regression. The subaqueous delta overlapped during several Yellow River channel runs (1897–1904, 1929–1934, 1938–1947, 1947–1953, 1976–1996) and the deposited sediment facies changed (the north tidal flat-abandoned subaqueous delta-lateral delta-delta front); (3) the deposited sediment characteristics can be revealed by studying the branched diversions of the Yellow River and coastal multi-rivers of the past one hundred years.     

Heavy metal contamination and their distribution in different size fractions of the surficial sediment of Haihe River, China

Heavy metal contamination and their distribution in different size fractions of the surficial sediment in Haihe River, China have been investigated. These results reveal that the heavy metal contamination of Haihe River is closely related to the contaminating sources along the river and has the order: Cd > Cu > Pb > Cr. The contents of these heavy metals in the sediment of Haihe River are at least two times higher than their background values and the highest contaminating metal, Cd, is 15.5 times higher than its background value and determined in the urban area of Tianjin city. The surficial sediments of Haihe River, with 70% particles smaller than 20 μm, belong to sandy clay containing about 28% clay and 42% silt. Electron micrographs and x-ray analysis show that the concentrations of heavy metals depend on the particle size of sediments. The highest concentrations for most metals exist in fine-grained sediments, which are mainly composed of silicates, oxides, and hydroxides of Si, Fe, and Al. In contrast, lower levels of heavy metals are usually found in the coarse sandy sediments, which are composed of quartz, feldspar, and other rocky substances. Based on the results in the present study of the surficial sediments of Haihe River, the contents of Cr, Cu, Pd, and Cd in finer sediments are 2.4, 3.9, 2.8, and 3.6 times higher than those in coarse sandy sediments, respectively. Obviously, because of rapid industrial development in this area during the last few decades, the surficial sediments of Haihe River, especially those finer fractions, have been seriously contaminated by heavy metals.     

莱州湾海洋沉积物粒度特征及其环境响应分析

基于20个柱状样粒度信息,文章对山东莱州湾海域1~3 m厚度的沉积环境展开了研究。莱州湾海域沉积物粒度组分以砂质和粉砂质为主,整体上分选性偏差,在沉积过程中受周边环境改造明显。莱州湾海洋沉积动力环境在粒度方面有较好的响应,柱状样粒度分布图反映不同海域沉积物所处的外力作用阶段各有不同,但总体上随着搬运距离增大,至中部浅海平原,概率累积曲线斜率逐渐变大,阶段分化愈发明显。莱州湾浅部海域共同环境敏感组分为3≤φ≤4,沿岸河流性质和泥沙输运路径对粒度组分影响明显。综合前人关于沉积速率的研究成果,表明莱州湾东部海域粒度组分阶段性变化与1855年黄河改道在时间上存在一定的对应关系。就沉积物形成环境而言,莱州湾中部海域沉积环境水动力较强,物质来源多样。屺坶岛—刁龙嘴海域沉积物的颗粒略粗,需要的临界起动速度较大,发生再悬浮的几率相对较小。黄河水下三角洲沉积环境比较动荡,能量不稳定,处于重力流后期,能量衰减并向牵引流转化。南部的水下岸坡在波浪、潮流作用下有一定量的泥沙淤积。     

Spatial distribution of heavy metals in soils: a case study of Changxing,China

Six hundred and sixty-five soil samples were taken from Changxing County in Zhejiang Province, China, to characterize the spatial variability of Hg Cd, Pb, Cu, As and Cr. The geostatistics and geographic information system (GIS) techniques were applied, and the ordinary kriging and lognormal kriging were used to map the spatial patterns of the six heavy metals. Hg, Pb, Cu and As were fitted to the spherical model with a range of 85.75, 82.32, 86.10, and 23.17 km, respectively. Cr was fitted to the exponential model with a range of 6.27 km, and Cd was fitted to the linear model with a range of 37.66 km. Both Pb and Cu had strong spatial dependence due to the effects of natural factors including parent material, topography and soil type. Hg, Cd, Cr and As had, however, moderate spatial dependence, indicating an involvement of human factors. Meanwhile, based on the comparison between the original data and the guide values of the six metals, the disjunctive kriging technique was used to quantify their pollution risks. The results showed that only Cd and Hg exhibited pollution risks in the study area. The pollution source evaluated was closely corresponded with the real discharge of industrial production and the application of organomercury pesticides. The results of this study provide insight into risk assessment of environmental pollution and decision making for agricultural production and industrial adjustment of building materials.     

Heterogeneous distribution of copper in different grain size and density fractions of contaminated surface sediment from Nansi Lake (China)

The copper (Cu) distributions and speciation in the surface sediment collected from Nansi Lake (NL) (China) were investigated by chemical and physical fractionation methods. Sediment was first fractionated into four grain size fractions (< 63, 78–163, 163–280, and > 280 μm) in wet condition. Each fraction was then further divided into two density sub-fractions (low and heavy) by flotation in sodium-polytungstate solution (ρ = 2.0 g/cm³). In addition, a three-stage extraction procedure following the European Communities Bureau of Reference (BCR) protocol was applied to study the speciation distribution of Cu among grain size fractions. It was found that the speciation distributions of Cu among different grain size fractions were quite close to each other, although the total Cu concentrations were different in the individual fractions. Moreover, Cu mainly occurred in the coarser, low density, OC-rich fractions. Extractable Cu, which was dominated by reducible and oxidizable parts, occupied almost 80% of the total Cu concentration. Total Cu concentrations in grain size fractions and density sub-fractions ranged from 29.6 to 72.9 and from 21.4 to 156 mg/kg dw, respectively. It was noted that low-density fractions had 4–7 times higher Cu concentrations and 5–12 times higher organic carbon (OC) content than those in high-density fractions. The results demonstrated that OC was a main factor influencing Cu distributions in either grain size or density fractionated sediment. This study suggests that the role of the Cu-rich fraction should be considered when conducting the remediation of Cu contamination in NL.     

Longshore grain size trends in the Kakinada-Mulapeta Beach,east coast of India

Shore-normal and shore-parallel variations in grain size statistics of beach sand have been studied over a period of one year along the Kakinada-Mulapeta coast. The southern beaches of this coast have been accretionary while the northern ones erosional since 125 years. The grain size gradings, beach and nearshore processes help in identifying (i) the Groins-fishing harbour beach influenced predominantly by the tidal regime. (ii) the Mulapeta-Vakalapudi beach influenced by refracted wave regime and (iii) the Vakalapudi-fishing harbour beach affected by both wave and tidal regimes at relatively subdued levels.     

Concentration distribution and assessment of several heavy metals in sediments of west-four Pearl River Estuary

Grain size parameters, trace metals (Co, Cu, Ni, Pb, Cr, Zn, Ba, Zr and Sr) and total organic matter (TOM) of 38 surficial sediments and a sediment core of west-four Pearl River Estuary region were analyzed. The spacial distribution and the transportation procession of the chemical element in surficial sediments were studied mainly. Multivariate statistics are used to analyses the interrelationship of metal elements, TOM and the grain size parameters. The results demonstrated that terrigenous sediment taken by the rivers are main sources of the trace metal elements and TOM, and the lithology of parent material is a dominating factor controlling the trace metal composition in the surficial sediment. In addition, the hydrodynamic condition and landform are the dominating factors controlling the large-scale distribution, while the anthropogenic input in the coastal area alters the regional distribution of heavy metal elements Co, Cu, Ni, Pb, Cr and Zn. The enrichment factor (EF) analysis was used for the differentiation of the metal source between anthropogenic and naturally occurring, and for the assessment of the anthropogenic influence, the deeper layer content of heavy metals were calculated as the background values and Zr was chosen as the reference element for Co, Cu, Ni, Pb, Cr and Zn. The result indicate prevalent enrichment of Co, Cu, Ni, Pb and Cr, and the contamination of Pb is most obvious, further more, the peculiar high EF value sites of Zn and Pb probably suggest point source input.     

厦门西港沉积环境变化及重金属的污染累积

通过测定柱状沉积物中的重金属、有机碳和硫化物含量, 结合沉积物粒度分析及现代沉积速率, 重现了厦门西港近70a的沉积环境变化及重金属的污染历史, 探讨了沉积环境对重金属累积过程的影响.结果表明, 厦门西港污染指示元素为Cu, Zn, Pb, As, 富集程度依次为As > Cu > Zn > Pb, 元素Cr, Cd和Hg在研究海域内没有富集现象.综观70a来, 厦门西港沉积物组成变化较大, 沉积环境变化明显, 重金属含量的垂向变化特征与当时的水动力、沉积环境变化紧密相关.研究表明, 沉积物来源越稳定, 沉积物粒径越小, 分选性越好, 则沉积物中重金属含量越高; 同时, 各层位的绝大部分重金属与有机碳和硫化物呈显著正相关关系.      

The effect of weathering on the grain-size distribution of red soils in south-eastern China and its climatic implications

Particle-size analysis is a useful way to determine the source and deposition of sediments. However, there are inconsistencies when this method is used to constrain the origin of the red soils in south-eastern China. To address this problem, we performed a detailed grain-size analysis of two red soil sequences in Xuancheng and Qiliting located along the lower reaches of the Yangtze River. By comparing their particle-size characteristics with those of the loess on the Loess Plateau in northern China, we found that the aeolian samples plot in a particular zone in the C–M (grain size of the cumulative 1% versus median grain size) plot and cluster nearer the lower left corner of the plot as their degree of weathering increases. The grain-size features suggest that the onset of large-scale aeolian deposition along the lower reaches of the Yangtze River occurred at approximately 0.8 Ma. Although both sedimentary sorting and post-depositional weathering control the grain-size variations in the deposits, the extremely strong weathering due to the humid, warm climate along the lower reaches of the Yangtze River primarily modified the grain-size distributions of the primary red soil deposits. Strong weathering increased the very fine silt (2–5 μm) fraction and decreased the coarse (>63 μm) fraction. We also found that certain grain-size parameters of the red soils varied with the weathering intensity, which can be used as indicators of palaeoclimate variations. The grain size variations in both the Qiliting and Xuancheng sequences suggest that the mid-Pleistocene climate transition (MPT) may have affected the lower reaches of the Yangtze River at 0.9 Ma.     

Determining the anthropogenic contribution of heavy metal accumulations around a typical industrial town: Xushe,China

Industrial emissions are the major sources of heavy metal pollutions. This study investigates the anthropogenic contribution of heavy metal accumulation surrounding an industrial town in China, using the component partition method. Results show that Cu, Ni, Pb, and As have higher concentrations compared with their background levels and the industrial town has a significant impact on heavy metal accumulations in its surrounding agricultural soil. Prevailing wind direction may explain the difference of heavy metal concentration in different directions. Anthropogenic components of Cu, Ni, Pb and As, which decrease with distance following exponential functions, account for 11.4%, 6.2%, 18.5% and 7.9% of their total concentrations, respectively. The natural components are modeled as the functions of physico-chemical variables through multiple regressions. The accumulating processes of heavy metals affected by industrial activities could be explained by anthropogenic and natural components, and thus, it could provide basic information for further simulation of heavy metal accumulations.     

海平面上升压力下厦门大学白城湾整治的探析

厦门大学白城湾为福建厦门岛南部、九龙江口外的一个小型海湾,水动力环境复杂。在海平面上升压力下,该区域的环境地质问题会进一步的突显。结合前人在此区域的研究成果,详细阐明海湾存在的环境地质问题,探讨有效合理防预整治措施,应对海平面上升而产生的影响,以期构建和谐的海湾环境。     

Sedimentary responses to the Pleistocene climatic variations recorded in the South China Sea

Grain-size analyses, coupled with end-member modelling, have been performed on the terrigenous fraction of two Leg 184 Ocean Drilling Program sites (1144 and 1146) from the South China Sea. The grain-size distributions over the last 1.8 Ma enable a new interpretation of their connections to sea-level variations and East Asian monsoon strength. Previous investigations in this area have associated grain-size variability with enhanced eolian input during glacial stages. End-member modelling downgrades the importance of this eolian contribution and indicates that the sediments can be described as a mixture of three end-members: fluvial mud inputs, shelf reworking and river mouth migration. Grain-size variations in the Pleistocene section of the cores indicate a multiple-stage evolution: (i) from 1.8 to 1.25 Ma, the downcore grain-size variations are low but show a correspondence between monsoon rainfall intensity and the fine grain-sized fluvial inputs; no link with sea-level variations is noticeable; (ii) from 1.25 to 0.9 Ma, there is an increase (decrease) in the intermediate (fine) end-member (∼ 100 kyr cycle) that is associated with the onset of a stronger summer monsoon and modest shelf reworking; (iii) from 0.9 to 0 Ma the grain-size record is dominated by global sea-level variations; each glacial stage is associated with extensive shelf reworking and conveyance of coarse particles to the basin.     

Contamination,chemical speciation and vertical distribution of heavy metals in soils of an old and large industrial zone in Northeast China

Heavy metal pollution of soils has become a major concern in China as a consequence of rapid urbanization and industrialization in recent years. However, the evaluation on soil heavy metal pollution in Shenyang, the largest heavy industrial base city in China, has not yet been conducted. In this study, accumulation, chemical speciation, and vertical distribution Cu, Zn, Pb and Cd in soils were studied and pollution condition was assessed in Tiexi Industrial District of Shenyang, the largest and oldest industrial zone in Northeastern China. The results showed that in topsoil, the average concentration of total Cu, Zn, Pb, and Cd was 209.06, 599.92, 470.19 and 8.59 mg kg⁻¹, respectively, much higher than the national threshold limit. The values of pollution index and integrated pollution index showed that the pollution level was Cd > Cu > Zn > Pb, and Cd, Cu and Zn belong to heavy pollution level. The residual, Fe and Mn oxide-bound, and organic-bound species accounted for about 90%, while carbonate-bound and exchangeable species accounted for about 10%. This study indicates that the soils in the industrial zone were widely and extremely polluted by multi-heavy metals as a result of long-term industrial activities.     

Spatial distribution features and environment effect of heavy metal in intertidal surface sediments of Guanhe estuary, Northern Jiangsu Province

In northern Jiangsu coastal zone area, Guanhe River is the biggest river and has the best navigation conditions among rivers which flow into the Yellow Sea. The grain sizes show gradual increase from the high intertidal zone to lower intertidal zone. The heavy metal values have slight changes along both sides of the river mouth, but show an evident change perpendicular to the tidal flat. In the latter case, they show a good correlation with grain size fluctuation, that is, the heavy metal values gradually decline when the grain size increases from the high intertidal zone to the lower intra-tidal zone. Analyses of the heavy metal elements show that on the Guanhe estuary surface sediment, the content of the elements Hg, As and Cu is above background values; Pb and Zn contents are rather close to the background values; and Cd content is less than the background values. The element Hg comes out to be harmful in a medium level to ecological environment, while the elements of Cr, As, Cu, Pb, Zn and Cd fall in a safe range of MPL. On the whole, Guanhe estuary tidal flat is not very harmful to the ecology in terms of the heavy metals. __________ Translated from Marine Geology & Quaternary Geology, 2007, 27(5): 23–32 [译自: 海洋地质与第四纪地质]     

Metals and grain size distributions in soil of the middle Rio Grande basin, Texas USA

 This paper deals with the problem of increased heavy metal constituents in agricultural soils due to the expanded use of fertilizers and elevated atmospheric deposition. It discusses the extent of contamination in soil and establishes an environmental monitoring program in the chosen area of concern in the southern coastal region of Texas. Grain size, pH, and metals (Cu, Cd, Zn, Pb, Ni, Ba, As, Cr, Mn, and Fe) were determined in soils of the middle Rio Grande basin. The soils were mainly of sand texture and alkaline in character. Fine sand constituted the major proportion of the soil, and clay and silt ranged from 8–30% of the soil. Correlations of metal concentrations to grain size and iron contents were performed. Metals, except Cd and Pb, gave positive to negative relationships with decreases in grain size. Silt gave no relationship with metal content while clay and silt had a positive relationship. All these metals had a positive correlation with iron in the soil. The results indicate metals are associated with coarse sand, clay, and iron hydroxides surfaces of the soil. The comparison of metal content in soil of the middle Rio Grande basin with metals from other areas of the world suggests that it is relatively uncontaminated. Received: 14 December 1998 · Accepted: 19 Jaunuary 1999     

胶州湾沉积物对海洋生物重金属富集的影响分析

本文对胶州湾沉积物和海洋生物重金属含量进行了统计分析。首先用地球化学法对海洋生物重金属富集特征进行了分析,然后用Spearman’s相关系数法分析了沉积物重金属含量和海洋生物重金属含量的相关性。分析结果表明鱼类对重金属的富集能力最差,而贝类和藻类较强;沉积物重金属均能促进或抑制海洋生物对重金属的富集,而对贝类的抑制作用最强。此结果可以为海洋生物的选择性养殖和种植提供依据。