Recent changes in heavy metal storage in flood-plain soils of the Lahn River,central Germany

Between 1995 and 2007, the concentrations of Pb and Zn in floodplain soils increased along a 60-km reach of the Lahn River, Germany, suggesting that the storage of some metals in the fluvial system is out of phase with recent declines in the release of metals to the environment. Re-sampling of surface soils to 5 cm along five transects perpendicular to the river indicated that the concentration of Pb increased between 1995 and 2007 along two transects and was statistically unchanged at the other three. The concentration of Zn increased at three of five transects and was statistically unchanged at two transects over the same time period. Between 1995 and 2007, concentrations of Cu were statistically equal along four of five transects and declined at the other transect. The increase in Pb and Zn was greater in a more rural than in a more urbanized reach of the Lahn River. Soil texture and organic matter content had virtually no impact on the concentration of metals. The increase in Pb concentration suggests a lag between the decline in Pb releases to the environment and its movement through the fluvial system. Increased Zn storage may result from the high solubility of the metal and the relative ease with which it moves through the environment. Environmental controls appear to have slowed Cu storage along the Lahn River, but are not yet reflected in Pb and Zn storage.     

Heavy metal concentrations in sediment deposits on the Tar River floodplain following Hurricane Floyd

The relation between the magnitude of a flood event and the resulting environmental impacts remains unclear. This study examines the impact of the flood of record on heavy metal deposition on the Tar River floodplain in eastern North Carolina, USA. Samples of sediment deposited on the floodplain following Hurricane Floyd were collected from 85 sites along the lower Tar River basin and analyzed for heavy metal concentration. The Hurricane Floyd event is the flood of record for the Tar River basin. Despite the magnitude of the flood, little suspended sediment was deposited on the floodplain. In almost all cases the deposition was less than 0.2 cm. There was variability in heavy metal content from site to site, but the overall concentrations were lower than might be expected for a flood of the magnitude of Floyd. To aid in comparison of contamination levels, the heavy metal concentrations were normalized to two environmental standards; the EPA preliminary remediation goals for residential soil and the general background concentrations of stream sediments throughout the Tar River basin. Most samples were highly enriched in heavy metals relative to the background concentration of stream sediments. However, samples were generally not contaminated relative to EPA PRG regulations. Arsenic, which was significantly elevated in nearly all samples, was the only exception. This contradiction makes it clear that the standard to which contaminants are compared must be considered carefully. The overall low concentration of heavy metals was likely the result of smaller flooding from Hurricane Dennis, 10 days prior to Hurricane Floyd, moving most of the stored sediment out of the basin prior to wide-spread overtopping of the banks. The implication is that event sequencing is as important as flood magnitude when examining environmental impacts.     

Heavy metal concentrations in soils and plants in the vicinity of Arufu lead-zinc mine,Middle Benue Trough,Nigeria

This study focused on the influence of base metal mining on heavy metal levels in soils and plants in the vicinity of Arufu lead-zinc mine, Nigeria. Soil samples (0-15 cm depth) and plant samples were collected from cul-tivated farmlands in and around the mine, the unmineralized site and a nearby forest (the control site). The samples were analyzed for heavy metals (Fe, Zn, Mn, Cu, Pb, Cr and Cd) by Atomic Absorption Spectrophotometry (AAS). The physical properties of soils (pH and LOI) were also measured. Results showed that soils from cultivated farm-lands have neutral pH values (6.5-7.5), and low organic matter contents (10%). Levels of Zn, Pb and Cd in culti-vated soils were higher than the concentrations obtained from the control site. These heavy metals are most probably sourced from mining and agricultural activities in the study area. Heavy metal concentrations measured in plant parts decreased in the order of rice leavescassava tuberspeelings. In the same plant species, metal levels decreased in the order of ZnFeMnCuPbCrCd. Most heavy metals were found in plant parts at average concentrations normally observed in plants grown in uncontaminated soil, however, elevated concentrations of Pb and Cd were found in a few cassava samples close to the mine dump. A stepwise linear regression analysis identified soil metal contents, pH and LOI as some of the factors influencing soil-plant metal uptake.     

广西八一锰矿区土壤和主要农作物重金属含量的研究

对广西八一锰矿废弃地土壤基本理化性质及重金属全量(浓HC l 浓HNO3 HF HC lO4消解)、有效态含量(0.1MHC l浸提)和主要农作物重金属含量(浓HNO3 HC lO4消解)进行了测定(AA S)。结果表明:土壤营养缺乏和重金属污染是本矿区生态恢复面临的主要问题。土壤中全磷和全氮含量低于正常指标,且部分C/N比值偏高,同时土壤存在严重的Cd污染,并可能受到M n污染。在锰矿恢复区种植的主要农作物中,部分样品中Pb、M n含量与全部样品的C r、Cd含量超出了植物正常含量范围。农作物的食用部分中Cd、C r、Pb含量普遍超过国家食品限量卫生标准,不宜食用。     

Toxic metal contamination in the lateral lakes of the Coeur d'Alene River valley, Idaho

 The 11 lateral lakes of Coeur d'Alene River valley in northern Idaho have received heavy metal contamination from over a century of upstream mining. The lateral lakes lie within the flood plain of the Coeur d'Alene River, and in their bottom sediments is preserved a stratigraphic record of the upstream mining operations. To characterize the contaminated sediments in the lateral lakes, sampling techniques, including the Livingston piston corer and the Huttenen freeze box, have been developed by Quaternary geologists to preserve the vertical stratigraphy in the samples. From 26 cm to over 55 cm of undisturbed tailing sediments, commonly with “varve-like” features, have been found in each of the lateral lakes, with maximum concentrations by weight of lead at 3.8%, zinc at 3.4%, arsenic at 340 mg/kg, cadmium at 120 mg/kg and mercury at 7 mg/kg. The contamination in the lakes appears to be restricted to the shallow subsurface and heavy metal concentrations generally drop to background levels within a meter of depth. Received: 22 May 1998 · Accepted: 21 September 1998     

Role of monsoon rain on concentrations and dispersion patterns of metal pollutants in sediments and soils of the Ganga Plain, India

 Monsoon rain causes large scale sediment-water movement and reworking of sediments of the Ganga Plain which is one of the largest fluvial systems on Earth. Geomorphology and drainage type combined with sedimentation processes play a substantial role on dispersion and transport patterns of metals bound to sediments and soils. The study area of Kanpur-Unnao industrial region in the Ganga Plain has been divided into five independent geochemical domains on the basis of sediment-geomorphic, hydrological and geochemical characters. The monsoon hydrography and physico-chemical parameters (pH, conductivity) of the river and urban drain waters play a prominent role in regulating the concentrations and behaviour of the metals in the aquatic system of the Ganga Plain. Values of pH and specific electrical conductivity of the river water of the study area decrease whereas those of the urban drain water increase in post-monsoon period. The monsoon rain reduces the contents of Co, C-org, Cr, Fe and Ni and enhances the contents of Cd, Sn and Zn in sediments of post-monsoon period. In soils, it reduces the contents of Al, Co, Fe, Mn and Ni and enhances the contents of Cd, Sn and Zn in the post-monsoon period. These changes in concentrations vary from metal to metal and from one geochemical domain to the other. An increase in the concentrations of few metals in the soils from pre- to post-monsoon periods indicates that these metals were mobilized from the overflooding of metal rich waste-water onto the fields during high water stage and also by reworking of the soils through sheet floods during the monsoon time. Despite the changes in concentrations, metal dispersion patterns in each domain remain similar both in pre- and post-monsoon periods which indicate that the geochemical and sediment-geomorphic processes operating for the metal dispersion and mobilization in sediments are persistent even after large scale sediment-water movement and reworking of the sediments during the monsoon period. Received: 4 May 1998 · Accepted: 20 October 1998     

Heavy metal pollution in freshly deposited sediments of the Yamuna River (the Ganges River tributary): a case study from Delhi and Agra urban centres, India

 The Yamuna River sediments, collected from Delhi and Agra urban centres, were analysed for concentration and distribution of nine heavy metals by means of atomic adsorption spectrometry. Total metal contents varied in the following ranges (in mg/kg): Cr (157–817), Mn (515–1015), Fe (28,700–45,300), Co(11.7–28.4), Ni (40–538), Cu (40–1204), Zn (107–1974), Pb (22–856) and Cd (0.50–114.8). The degree of metal enrichment was compared with the average shale concentration and shows exceptionally high values for Cr, Ni, Cu, Zn, Pb and Cd in both urban centres. In the total heavy metal concentration, anthropogenic input contains 70% Cr, 74% Cu, 59% Zn, 46% Pb, 90% Cd in Delhi and 61% Cr, 23% Ni, 71% Cu, 72% Zn, 63% Pb, 94% Cd in Agra. A significant correlation was observed between increasing Cr, Ni, Zn, and Cu concentrations with increasing total sediment carbon and total sediment sulfur content. Based on the Müller's geoaccumulation index, the quality of the river sediments can be regarded as being moderately polluted to very highly polluted with Cr, Ni, Cu, Zn, Pb and Cd in the Delhi and Agra urban centres. The present sediment analysis, therefore, plays an important role in environmental measures for the Yamuna River and the planning of these city centres. Received: 21 June 1999 · Accepted: 1 October 1999     

Hydrochemical evolution and environmental features of Salso River catchment, central Sicily (Italy)

 A hydrogeochemical study of the Salso River highlighted the chemical and isotopic space-time evolution along its flow path and the main contamination processes. Within the basin, three different hydrogeochemical facies have been individuated: (1) Ca-Mg-HCO₃, (2) Ca-Mg-SO₄ and (3) Na-Cl. The first facies reflects the chemical composition of the groundwaters hosted in the carbonate reliefs that belong to the Madonie Mountains. The second and the third facies are the result of the interaction processes between surface waters and the gypsum and salty clays, respectively. Two pollution sources have been also located in the basin downstream from the salt mine and downstream from a discharge area of wastewater from the town of Gangi. On the basis of the location of natural and anthropogenic pollution sources, the waters available for drinking and irrigation use are also indicated. Received: 16 July 1999 · Accepted: 22 December 1999     

Heavy metal concentrations in water and surface sediments of Maharlou Lake, SE of Shiraz, Iran

The main objective of this study is to evaluate trace metal distribution and identify their sources in the Maharlou Lake. Trace metals （Cr, Co, Ni, Cu, Zn, Cd, Pb） and major elements （A1, Ca, Fe, K, Mg, Mn, Na, P） were investigated in water and surface sediments. There was a negative relationship between the depth of water and heavy metal concentration. Metal concentrations in water and sediment samples show a high variability and decrease in this order： Al〉Fe〉Ni〉Co〉Pb〉Zn〉Cu〉Mn〉Cd. In the northern parts of the lake, especially at the inflow of drains and the Khoshk River of Shiraz City, metal concentrations are higher in both water and sediment samples. In order to assess the heavy metal enrichment in sediment samples, trace metal concentrations were normalized for Al. Except for Mn, all metals are enriched relative to average crust and average sedimentary rocks. Also, the results showed that stations located at the northern coast of the lake, have higher enrichment factors （EF） than the other stations. The results of this study showed that the Khoshk River and other drains are the main pollutant sources of the Maharluo Lake.     

珠江三角洲潜在生态风险:土壤重金属活化

珠江三角洲典型土壤模拟酸雨提取实验表明，土壤酸缓冲能力为菜园土大于水稻土大于赤红壤。酸化过程早期，铝铁胶体吸附共沉淀导致重金属溶出量增长不明显甚至下降；进一步酸化时，多数元素溶出量与加入酸量呈显著正相关。计算表明，在pH=4．5的酸雨作用下，溶液中Hg、Mn、Pb、Fe(以Fe2O3表示)浓度已超出Ⅱ级地表水标准，Cu、Zn大大高于渔业用水标准。可见，土壤元素活化溶出对水体生态环境有潜在的危害。     

Heavy metals in freshly deposited sediments of the Gomati River (a tributary of the Ganga River): effects of human activities

 The concentrations of various metals (Cr, Cu, Co, Fe, Mn, Ni, Pb, Zn, and Cd) were determined in recently deposited surface sediments of the Gomati River in the Lucknow urban area. Markedly elevated concentrations (milligrams per kilogram) of some of the metals, Cd (0.26–3.62), Cu (33–147), Ni (45–86), Pb (25–77), and Zn (90–389) were observed. Profiles of these metals across the Lucknow urban stretch show a progressive downstream increase due to additions from 4 major drainage networks discharging the urban effluents into the river. The degree of metal contamination is compared with the local background and global standards. The geoaccumulation index order for the river sediments is Cd>Zn>Cu>Cr>Pb. Significant correlations were observed between Cr and Zn, Cr and Cu, Cu and Zn and total sediment carbon with Cr and Zn. This study reveals that the urbanization process is associated with higher concentrations of heavy metals such as Cd, Cu, Cr, Pb, and Zn in the Gomati River sediments. To keep the river clean for the future, it is strongly recommended that urban effluents should not be overlooked before their discharge into the river. Received: 16 February 1996 · Accepted: 29 February 1996     

Lake and reservoir water quality affected by metals leaching from tropical soils, Bangladesh

 The release of metals during weathering has been studied in order to assess its geochemical controls and possible effects on environmental health in Bangladesh. A total of 27 soil samples and 7 surface water samples were collected from four locations covering three major regions in the country. Results show that weathering effects are a strong function of climatic conditions. Surface waters are typically enriched in Al, Mg, Ca, Na, K, As, Ba, Cr, Cu, Ni, Pb and Zn. The solubility of metal ions, organometallic complexes, co-precipitation or co-existence with the colloidal clay fraction are the main processes that lead to metal enrichment in lake and reservoir water. Aluminium concentrations exceed World Health Organization (WHO) drinking-water standards in all samples, and in two regions, arsenic concentrations also significantly exceed WHO standards. The elevated levels of As indicate that arsenic contamination of water supplies in Bangladesh is not confined to groundwater. Received: 4 June 1999 · Accepted: 17 August 1999     

Trace metal concentrations in lake and overbank sediments in southern Norway

 As, Be, Cd, Co, Cr, Cu, Hg, Ni, Pb, V, Se and Zn concentrations were determined and compared in lake and overbank sediments from 33 catchments without local pollution sources in southern Norway. There were no significant differences in concentrations of Be, Co, Cr, Cu, Ni, and V in overbank and pre-industrial lake sediments. In areas with shallow overburden, and significant influence from long-range atmospheric pollution, concentrations of As, Cd, Hg, Pb, Se, and Zn in overbank sediments were probably modified by vertical percolating water. In such areas, we suggest using lake sediments as a better sampling medium for mapping pre-industrial concentrations. Pre-industrial lake sediments yield natural concentrations of Hg and Se, which consist of both geogenic and natural atmospheric deposition. Important covariables like organic carbon content, Fe oxides, and fine mineral fraction were generally higher in pre-industrial lake sediments as compared to overbank sediments. By adjusting for such differences overbank sediments could be used as an alternative in mapping background concentrations of trace metals in regions with few lakes. Received: 19 February 1999 · Accepted: 17 April 1999     

京杭大运河镇江段近岸土壤重金属含量与空间分布特征

通过多目标区域地球化学调查方法,研究了京杭大运河镇江段流域近岸土壤中重金属元素的含量、来源及空间分布特征。结果表明：重金属含量总体较低,仅局部地区存在重金属污染,其中Cr、Ni、As未见明显污染,Cu、Pb、Zn、Hg、Cd在局部地区存在不同程度的污染,尤其是Cd污染最严重;污染区域主要位于辛丰镇和丹阳城区附近,污染源主要为附近的金属制品业和钢铁厂。     

The relationship between the water table and the surface flow of a losing stream, lower Medano Creek, Great Sand Dunes National Monument, Colorado

 Proposed groundwater withdrawals in the San Luis Valley of Colorado may lower the water table in Great Sand Dunes National Monument. In response, the National Park Service initiated a study that has produced a generalized conceptual model of the hydrologic system in order to assess whether a lowering of the water table might decrease the surface flow of lower Medano Creek. Based upon information obtained during the drilling of several boreholes, there appear to be five important hydrostratigraphic units underlying lower Medano Creek within the upper 30 m of the ground surface: 1. a perched aquifer overlying an aquitard located between about 5 and 6 m below the ground surface; 2. the aquitard itself; 3. an unconfined aquifer located between the upper and lower aquitards; 4. an aquitard located between about 27 and 29 m below the ground surface; and 5. a confined underlying the lower aquitard. Because the areal extent of the aquitards cannot be determined from the borehole data, a detailed conceptual model of the hydrogeologic system underlying lower Medano Creek cannot be developed. However, a generalized conceptual model can be envisioned that consists of a complex system of interlayered aquifers and leaky aquitards, with each aquifer having a unique hydraulic head. Water levels in the perched aquifer rise rapidly to their annual maximum levels in response to the arrival of the flow terminus of Medano Creek during the spring runoff event, and the location of the flow terminus is directly dependent upon the discharge of the creek. Water levels in the deeper, non-perched aquifers do not appear to fluctuate significantly in response to the arrival of the flow terminus, demonstrating that it is unlikely that the proposed groundwater withdrawals will decrease the surface flow of lower Medano Creek. Received: 27 December 1995 · Accepted: 20 February 1996     

Measurement of free heavy metal ion concentrations in soils using Donnan membrane technique

In natural systems heavy metals are present in very low concentrations (less than micro-molar) , so precise measurement of the free metal ions is difficult. Recently, a new method has been developed called the Donnan membrane technique (DMT). Several heavy metals could be measured simultaneously using this method. Furthermore, all the metals did not interfere with each other, and the balance between the measured system and the surrounding condition could not be disturbed. Improvements were made according to the internal condition. The free heavy metal ion concentrations were measured in different systems using the improved method, and satisfied results have been obtained.     

Trace element contents and correlation in surface soils in China's eastern alluvial plains

 A study investigating the contents of 13 trace elements and the correlations between these trace elements and soil parameters of the surface soils in the eastern alluvial plains of China is summarized and discussed in this paper. The results show that the contents of some elements studied differ from region to region. Close relations have been noted between all the trace element contents in the soils of the eastern alluvial plains and the relevant surface materials of erosion regions, which demonstrate the effects of parent materials, while climatic conditions and human interventions are also found to be important factors. Close relations were found between the transition elements of the Quaternary period and the chalcophile elements (except Cu). The chemical and geochemical properties of these elements are identified as beeing important inherent characteristics that affect the relations of these elements in the soils. Received: 5 June 1997 · Accepted: 2 March 1998     

Mine waste dumps and heavy metal pollution in abandoned mining district of Boccheggiano (Southern Tuscany, Italy)

 Mining activity in the Boccheggiano-Fontalcinaldo area (Southern Tuscany) dates back at least to the 16th century AD and lasted up to very recent times. Copper-rich hydrothermal veins, massive pyrite deposits, and their gossans were exploited. Two mine waste dumps (Fontalcinaldo, Fontebona), one flotation tailings impoundment (Gabellino), and one roasting/smelting waste dump (Merse-Ribudelli) in the study area were selected to ascertain the environmental effects of such protracted mining activity. Primary waste mineralogy is mainly characterized by pyrite, gypsum, quartz, carbonates, chlorites, and micas. Secondary oxidation mineralogy includes Fe and Cu sulfates and hydroxy sulfates, Cu carbonates, Fe and Al oxyhydroxides, and other phases [neogenic cassiterite at Fontalcinaldo; probable calkinsite, (Ce,La)₂(CO₃)₃· 4H₂O, at Fontebona]. Mine waste samples show extremely variable contents of toxic elements (Cu, Pb, Zn, Bi, Cd, As), with average values in the order of hundreds to thousands of parts per million (except for Bi and Cd). In some samples, the abundance of proper minerals of these metals cannot account for the entire metal load. Conceivably, either solid solution substitutions or adsorption processes contribute to the intake of released metals into newly formed minerals. Release and transport of pollutants was affected to variable degrees by acid-neutralization processes. The highest metal and acid concentrations occur close to the investigated wastes and rapidly decrease moving downstream some hundreds of meters or less, with the partial exception for Mn and Fe. Other than dilution effects, this phenomenon may be ascribed to metal adsorption and precipitation of solid phases. Received: 16 April 1995 · Accepted: 14 December 1995     

黄河下游山东段沿岸土壤中重金属元素异常的成因

山东省多目标区域地球化学调查发现,沿黄河两岸分布有As、Cd、Cr、Cu、Pb、Zn、Ni等重金属元素异常,这类异常衬度不大,并多沿河呈不连续分布。研究结果表明,异常区土壤重金属元素的含量与SiO2、Al2O3Fe2O3等常量组分间具有显著的相关性,多数微量重金属元素随SiO2含量的增加而降低,随Al2O3Fe2O3含量的增加而增加。根据常量组分与土壤质地的密切关系可以推断。土壤质地对重金属元素异常的形成具明显的控制作用。     

Heavy metal pollution of coastal river sediments, north-eastern New South Wales, Australia: lead isotope and chemical evidence

 Heavy metal and metalloid concentrations within stream-estuary sediments (<180-μm size fraction) in north-eastern New South Wales largely represent natural background values. However, element concentrations (Ag, As, Cd, Cr, Cu, Hg, Ni, Pb, Sb, Zn) of Hunter River sediments within the heavily industrialized and urbanized Newcastle region exceed upstream background values by up to one order of magnitude. High element concentrations have been found within sediments of the Newcastle Harbour and Throsby Creek which drains into urbanized and light industry areas. Observed Pb enrichments and low ²⁰⁸Pb/²⁰⁴Pb, ²⁰⁷Pb/²⁰⁴Pb and ²⁰⁶Pb/²⁰⁴Pb ratios are likely caused by atmospheric deposition of Pb additives from petrol and subsequent Pb transport by road run-off waters into the local drainage system. Sediments of the Richmond River and lower Manning, Macleay, Clarence, Brunswick and Tweed River generally display no evidence for anthropogenic heavy metal and metalloid contamination (Ag, As, Cd, Cr, Cu, Hg, Ni, Pb, Sb, Zn). However, the rivers and their tributaries possess localized sedimentary traps with elevated heavy metal concentrations (Cu, Pb, Zn). Lead isotope data indicate that anthropogenic Pb provides a detectable contribution to investigated sediments. Such contributions are evident at sample sites close to sewage outlets and in the vicinity of the Pacific Highway. In addition, As concentrations of Richmond River sediments gradually increase downstream. This geochemical trend may be the result of As mobilization from numerous cattle-dip sites within the region into the drainage system and subsequent accumulation of As in downstream river and estuary sediments. Received: 5 September 1997 · Accepted: 4 November 1997