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1.
The aim of this research was to determine how fast the level of heavy metal concentrations in the air decreases in relation to increasing distance from the source of pollution and what the influence area is of the zinc smelting plant which existed for 100 years in Celje. In that period it produced approximately 580,000 tons of raw Zn from sphalerite ore by the pyrometallurgical process. The production left behind a heavily contaminated area, where the concentrations of Pb and Zn in the soil can be expressed as a percentage. A model has been made on the basis of the data of concentrations of Zn and Cd in the soil and attic dust regarding the distance and direction from the source of the pollution. Because Celje lies in a basin we chose a linear model, which describes the decreasing of the concentrations of Zn and Cd only in one direction. Sampling has been conducted on the four river valleys which stretch from the source of the pollution in all four directions: north, west, south and east, up to 13 km from the source. The power function with a negative exponent was used. With the solution to the calculated functions according to the distance, we can estimate the theoretical distance when the concentrations drop to the natural background level. The range of influence of the zinc smelting plant has been estimated to be between 14 and 52 km for the presence of anthropogenic Zn in attic dust and between 9 and 14 km for the presence of anthropogenic Zn in the soil, depending on the direction from the plant. Correlations between the measured values and the ones from the model are high: from 0.75 up to 0.98.  相似文献   

2.
A soil-based geochemical survey was carried out in an area of about 350 km2 in northern Kosovo around the Zve?an Pb-Zn smelter. The concentrations of As, Cd, Co, Cr, Cu, Ni, Pb, Sb, Tl, Th, U, Zn were determined in 452 topsoil and 82 subsoil samples. High contents of Pb, Cd, As, Sb, Zn and Cu were found in topsoil over a vast area including the Ibar and Sitnica river valleys. The highest concentrations were usually measured close to the Zve?an smelter. In some zones, the lead contents in surface soils exceeded 5000 mg/kg. Arsenic and antimony levels were usually more than 200 and 50 mg/kg, respectively, while cadmium contents were in the range 5-20 mg/kg. South of the Zve?an area, lead, antimony and cadmium pollution was strong in the densely populated urban area of Kosovska Mitrovica and along the agricultural alluvial plain of the Sitnica River. Depending on the chemical element, the pollution extended 15-22 km north and south of the Zve?an smelter. There was a progressive decrease of heavy element concentrations with increasing distance from the smelting plant. The contents of Pb, Zn, Cu, As, Cd, Sb significantly decreased with soil depth; in fact, the pollution only affected the upper 50 cm of soil. Crops were affected by soil pollution and many food-stuffs exceeded the EU standards. Suggestions for soil remediation are given.  相似文献   

3.
Eleven surface soil samples from calcareous soils of industrial areas in Hamadan Province, western Iran were analyzed for total concentrations of Zn, Cd, Ni, Cu and Pb and were sequentially extracted into six fractions to determine the bioavailability of various heavy metal forms. Total Zn, Cd, Ni, Cu and Pb concentrations of the contaminated soils were 658 (57–5,803), 125.8 (1.18–1,361), 45.6 (30.7–64.4), 29.7 (11.7–83.5) and 2,419 (66–24,850) mg kg−1, respectively. The soils were polluted with Zn, Pb, and Cu to some extent and heavily polluted with Cd. Nickel values were not above regulatory limits. Copper existed in soil mainly in residual (RES) and organic (OM) fractions (about 42 and 33%, respectively), whereas Zn occurred essentially as RES fraction (about 69%). The considerable presence of Cd (30.8%) and Pb (39%) in the CARB fraction suggests these elements have high potential biavailability and leachability in soils from contaminated soils. The mobile and bioavailable (EXCH and CARB) fractions of Zn, Cd, Ni, Cu, and Pb in contaminated soils averaged (7.3, 40.4, 16, 12.9 and 40.8%), respectively, which suggests that the mobility and bioavailability of the five metals probably decline in the following order: Cd = Pb > Ni > Cu > Zn.  相似文献   

4.
This study was aimed at evaluating the mechanical and pH-dependent leaching performance of a mixed contaminated soil treated with a mixture of Portland cement (CEMI) and pulverised fuel ash (PFA). It also sought to develop operating envelopes, which define the range(s) of operating variables that result in acceptable performance. A real site soil with low contaminant concentrations, spiked with 3000 mg/kg each of Cd, Cu, Pb, Ni and Zn, and 10,000 mg/kg of diesel, was treated with one part CEMI and four parts PFA (CEMI:PFA = 1:4) using different binder and water contents. The performance was assessed over time using unconfined compressive strength (UCS), hydraulic conductivity, acid neutralisation capacity (ANC) and pH-dependent leachability of contaminants. With binder dosages ranging from 5% to 20% and water contents ranging from 14% to 21% dry weight, the 28-day UCS was up to 500 kPa and hydraulic conductivity was around 10−8 m/s. With leachant pH extremes of 7.2 and 0.85, leachability of the contaminants was in the range: 0.02–3500 mg/kg for Cd, 0.35–1550 mg/kg for Cu, 0.03–92 mg/kg for Pb, 0.01–3300 mg/kg for Ni, 0.02–4010 mg/kg for Zn, and 7–4884 mg/kg for total petroleum hydrocarbons (TPHs), over time. Design charts were produced from the results of the study, which show the water and/or binder proportions that could be used to achieve relevant performance criteria. The charts would be useful for the scale-up and design of stabilisation/solidification (S/S) treatment of similar soil types impacted with the same types of contaminants.  相似文献   

5.
The concentration of heavy metals such as Ba, Co, Cr, Cu, Ni, Pb, Rb, Sr, V, Y, Zn, Zr were studied in soils of Balanagar industrial area, Hyderabad to understand heavy metal contamination due to industrialization and urbanization. This area is affected by the industrial activities like steel, petrochemicals, automobiles, refineries, and battery manufacturing generating hazardous wastes. The assessment of the contamination of the soils was based on the geoaccumulation index, enrichment factor (EF), contamination factor, and degree of contamination. Soil samples were collected from Balanagar industrial area from top 10–50 cm layer of soil. The samples were analyzed using X-ray fluorescence spectrometer for heavy metals. The data revealed that the soils in the study area are significantly contaminated, showing high level of toxic elements than normal distribution. The ranges of concentration of Cr (82.2–2,264 mg/kg), Cu (31.3–1,040 mg/kg), Ni (34.3–289.4 mg/kg), Pb (57.5–1,274 mg/kg), Zn (67.5–5819.5 mg/kg), Co (8.6–54.8 mg/kg), and V (66.6–297 mg/kg). The concentration of above-mentioned other elements was similar to the levels in the earth’s crust pointed to metal depletion in the soil as the EF was <1. Some heavy metals showed high EF in the soil samples indicating that there is a considerable heavy metal pollution, which could be correlated with the industries in the area. A contamination site poses significant environmental hazards for terrestrial and aquatic ecosystems. They are important sources of pollution and may results in ecotoxicological effects on terrestrial, groundwater and aquatic ecosystems.  相似文献   

6.
 The Ganga Plain is one of the most densely populated regions and one of the largest groundwater repositories of the Earth. For several decades, the drainage basin of the Ganga Plain has been used for the disposal of domestic and industrial wastes which has adversely affected the quality of water, sediments and agricultural soils of the plain. The concentrations of Al, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sn, Zn and organic carbon were determined in river sediments and soils of the Ganga Plain in the Kanpur-Unnao industrial region in 1994 and 1995 (pre-monsoon period of April–May). High contents (maximum values) of C-org (12.0 wt. %), Cr (3.40 wt. %), Sn (1.92 wt. %), Zn (4000 mg/kg), Pb (646 mg/kg), Cu (408 mg/kg), Ni (502 mg/kg) and Cd (9.8 mg/kg) in sediments (<20 μm fraction); and C-org (5.9 wt. %), Cr (2.16 wt. %), Sn (1.21 wt %), Zn (975 mg/kg) and Ni (482 mg/kg) in soils (<20 μm) in the pre-monsoon period of 1994 were found. From 1994 to 1995 the contents of Fe and Sn in sediments increase whereas those of C-org, Cd, Cu, Ni and Zn decrease. Considering the analytical errors, Al, Co, Cr, Mn and Pb do not show any change in their concentrations. In soils, the contents of Cd, Fe and Sn increase whereas those of Ni decrease from 1994 to 1995. Aluminium, Co, Cr, Cu, Mn, Pb and Zn do not show any change in their concentrations from 1994 to 1995. About 90% of the contents of Cd, Cr and Sn; 50–75% of C-org, Cu and Zn; and 25% of Co, Ni and Pb in sediments are derived from the anthropogenic input in relation to the natural background values, whereas in soils this is the case for about 90% of Cr and Sn; about 75% of Cd; and about 25% of C-org, Cu, Ni and Zn. The sediments of the study area show enrichment factors of 23.6 for Cr, 14.7 for Cd, 12.2 for Sn, 3.6 for C-org, 3.2 for Zn, 2.6 for Cu and 1.6 for Ni. The soils are enriched with factors of 10.7 for Cr, 9.0 for Sn, 3.6 for Cd, 1.8 for Ni and 1.5 for Cu and Zn, respectively. Received: 3 March 1998 · Accepted: 15 June 1998  相似文献   

7.
The abandoned Hg mine in Podljubelj was in operation with interceptions from 1557 to 1902. The entire operating period yielded about 110 000 tons of ore, from which 360 tons of Hg was produced. The objective of the research project was to establish the contents and spatial distribution of Hg in soils and stream sediments in the vicinity of the mine. On an area of 88 ha the soil was sampled in a 100 × 100 m grid. Two soil horizons (0–5 cm and 20–30 cm) were sampled in order to distinguish between geogenic and anthropogenic Hg sources. It was established that on an area of about 9 ha Hg content in soil exceeds The New Dutchlist action value for Hg (10 mg/kg). Total Hg concentrations in soil samples vary between 0.17 and 719 mg/kg, with a mean of 3.0 mg/kg. Mercury contents in stream sediments range from 0.065 to 1.4 mg/kg, with a mean of 0.64 mg/kg. The highest determined value in soils was found in the area around the former roasting furnace, where the ore was processed. Increased Hg concentrations were also found on the mine waste dump (108 mg/kg). Mercury contents in soils generally decrease with soil profile depth and with the distance from the mine and from the roasting furnace location. Mercury also appears in higher concentrations along the road that runs through the valley, which results from the use of Hg-bearing ore residues in road construction. The average enrichment factor (EF) of Hg in topsoil with respect to subsoil is 3.3. Calculated enrichment factors show higher values also for Cd (3.2), Pb (2.7), Ca (2.4) and P (1.9). The average enrichment factor of Hg in topsoil with regard to the established Slovenian soil averages (EFslo) is 19. EFslo of other determined chemical elements do not exceed 3.0.  相似文献   

8.
Determination of the origin of heavy metals in the household dust and street sediment in a previously heavily contaminated area was carried out. The main question addressed was the origin of heavy metals in dry and wet air deposits measured in the environmental monitoring programme of the community of Celje. There are two possible sources: present atmospheric emissions by industries in Celje and dusting of previously heavily contaminated soil. Determination of the present emissions was done on the basis of a method based on enrichment factor calculations. Samples of soil, street sediment and household dust in the contaminated area and in a non-contaminated sampling point were analysed. Expected heavy metal concentrations in household dust and street sediment in the previously heavily polluted area according to the level of measured soil contamination were calculated. Expected and measured values were compared to detect possible present atmospheric emissions. The data show higher enrichment with elements related to ironworking activities (Fe, Co, Cr, Mn, Ni) in household dust and street sediment, according to the concentrations in the soil in the vicinity of ironworks in comparison to the reference point. Similar observations can be made at the sampling point, east of a factory producing TiO2-based white pigment for Ti, because emissions from it are expected. In contrast, the same trend is not observed for elements related to pollution problems in Celje (Cd, Zn, Pb). This indicated that street sediment and household dust might be a good tracer of present atmospheric emissions, despite the fact that the environment was previously highly contaminated. The method yields good results, which fit very well with expectations.  相似文献   

9.
Fractionation of heavy metals (HMs) in amended soils is needed to predict elemental mobility in soil and phytoavailability to plants. A study was conducted to determine the effects of different amendments on HMs availability and their redistribution among soil fractions. A contaminated soil was selected from around a Zn mine and amended with 0, 2, 4, and 6 g kg−1 of vermicompost (VC), zeolite (ZE), and di-ammonium phosphate (DP) and incubated at field moisture. The amounts of Cd, Pb, Zn, and Cu were determined from the soil after 6 months of incubation time using DTPA and sequential extraction procedures. The total concentrations of Cd, Pb, Zn, and Cu were 41, 3,099, 1,997, and 83 mg kg−1 of soil, respectively. All amendments decreased significantly [probability (p) ≤ 0.05] DTPA-extractable Cd, Pb, and Cu, but not Zn, in the soil. For instance, DTPA-extractable Cd, Pb, and Cu decreased by 40, 290, and 20%, respectively, and that of Zn increased by 18% with DP1 (2 g kg−1 of di-ammonium phosphate) application. The concentrations of Pb and Cd decreased mainly in the specifically sorbed (SS) but increased in the amorphous Fe oxide (AFeO) fraction with DP application, indicating redistribution of Pb and Cd in the fractions with less mobility. Lead immobilization by DP was mainly attributed to the P-induced formation of chloropyromorphite, which was identified in the DP treatment using X-ray diffraction technique. It was concluded that DP was the most effective amendment in immobilizing Pb and Cd, though it increased Zn mobility.  相似文献   

10.
This study aims at assessing the extent of total mercury (Hg) contamination in urban and agricultural soils under long-term influence of a chlor-alkali plant, located at about 1 km away from a town centre. Moreover, it aims at identifying the main factors controlling Hg contents’ distribution and associated potential hazards to environment and human health. The median value of total Hg for soil surface layer (0–10 cm) was 0.20 mg/kg (data ranging from 0.050 to 4.5 mg/kg) and for subsurface layer (10–20 cm) 0.18 mg/kg (data ranging from 0.046 to 3.0 mg/kg). The agricultural area showed higher Hg concentrations (ranging from 0.86 to 4.5 mg/kg) than urban area (ranging from 0.05 to 0.61 mg/kg), with some results exceeding target values set by the Dutch guidelines. Mercury concentrations observed in the studied area are more likely to be associated with the influence of the chlor-alkali plant and with the use of historically contaminated sludges and water from a nearby lagoon in agriculture, than to the impacts of urban development. The statistical correlations between Hg concentrations and soil properties suggest that anthropogenic metal sources should influence the spatial distribution more than the geological properties. Although the Hg emissions were drastically reduced 10 years ago, the area under influence of the chlor-alkali plant is still facing potential health and environmental threats arising from soil contamination.  相似文献   

11.
成都经济区近地表大气尘中重金属元素含量空间分布显示,经济区中东部高于西部,北部高于中南部,重工业城市高于综合性城市和旅游城市,工矿影响区元素含量总体偏高,人口密集的平原区高于山区。通过标准极限方法确定了近地表大气尘中元素的“极限浓度”,以低于“极限浓度”值统计确定了地球化学基线值：As为28.6mg/kg 、Hg 0.63mg/kg 、Cd 2.94mg/kg、Cr 110mg/kg、Pb 281mg/kg、Ni 32mg/kg、Zn 535mg/kg。近地表大气尘中元素地球化学基线与区域地质背景和矿产开发有关,矿业活动、工业活动及居民生活是造成近地表大气尘中人为扰动元素含量偏高的主要原因。  相似文献   

12.
An exploratory study on soil contamination of heavy metals was carried out surrounding Huludao zinc smelter in Liaoning province, China. The distribution of total heavy metals and their chemical speciations were investigated. The correlations between heavy metal speciations and soil pH values in corresponding sites were also analyzed. In general, Cd, Zn, Pb, Cu and As presented a significant contamination in the area near the smelter, comparied with Environmental Quality Standards for Soils in China. The geoaccumulation index showed the degree of contamination: Cd > Zn > Pb > Cu > As. There was no obvious pollution of Cr and Ni in the studied area. The speciation analysis showed that the dominant fraction of Cd and Zn was the acid soluble fraction, and the second was the residual fraction. Pb was mostly associated with the residual fraction, which constituted more than 50% of total concentration in all samples. Cu in residual fraction accounted for a high percentage (40–80%) of total concentration, and the proportion of Cu in the oxidizable fraction is higher than that of other metals. The distribution pattern of Pb and Zn was obviously affected by soil pH. It seemed that Pb and Zn content in acid solution fraction increased with increasing soil pH values, while Cd content in acid soluble fraction accounted for more proportion in neutral and alkaline groups than acidic one. The fraction distribution patterns of Cu in three pH groups were very similar and independent of soil pH values. And the residual fraction of Cu took a predominant part (50%) of the total content.  相似文献   

13.
In a reconnaissance study, trace amounts of Cd, Cu, Pb, and Zn were determined in “A-zone” soil from 22 locations in the Dayton, Ohio, area. Soil samples were collected at high-volume air monitoring sites in urban, suburban, and rural areas. Measurable amounts of the elements were found in all of the samples. Positive correlations occur between each metal and particulate matter, with correlation coefficients of aboutr=0.70, at the 99% confidence level. Natural background values for the elements were measured in soil from rural areas. Theoretical background values, which are very close to those measured, were calculated from the individual regression equations. Natural background levels do not exceed 1.00 ppm Cd, 15 ppm Cu, 25 ppm Pb, and 55 ppm Zn. The heavy metal contents of most soils in the area exceed background by factors of up to 3.0 for Cd, up to 4.5 for Cu, up to 11 for Pb, and up to 4.5 for Zn. Significant positive correlations among the metals suggest a common source (or sources) for at least some, if not most, of the heavy metals. For the most part, the highest metal values are found in soils near coal-burning plants. Fly ash from a local plant contains substantial amounts of the elements. The high lead values are largely due to vehicular exhaust. However, there is evidence that the metals can also come from the normal deterioration of vehicles. It appears that airborne pollution is an important source of heavy metals in Dayton area soils.  相似文献   

14.
Concentration and distribution of heavy metals (Cd, Cu, Pb and Zn) in urban soils of Hangzhou, China, were measured based on different land uses. The contamination degree of heavy metals was assessed on the basis of pollution index (PI), integrated pollution index (IPI) and geoaccumulation index (I geo). The 0.1 mol l−1 HCl extraction procedure and gastric juice simulation test (GJST) were used to evaluate the potential mobility and environmental risk of heavy metals in urban soils. The average concentration of Cd, Cu, Pb and Zn in urban soils was measured at 1.2 (with a range of 0.7–4.6), 52.0 (7.4–177.3), 88.2 (15.0–492.1) and 206.9 (19.3–1,249.2) mg kg−1, respectively. The degree of contamination increased in the order of industrial area (IA) > roadside (RS) > residential and commercial areas (RC) > public park and green areas (PG). The PIs for heavy metals indicated that there is a considerable Cd, Cu, Pb and Zn pollution, which originate from traffic and industrial activities. The IPI of these four metals ranged from 1.6 to 11.8 with a mean of 3.5, with the highest IPI in the industrial area. The assessment results of I geo also supported that urban soil were moderately contaminated with Cd and to a lesser extent also with Cu, Pb and Zn. The IP and I geo values reveal the pollution degree of heavy metal was the order of Cd > Pb > Zn ≈ Cu. It was shown that mobility and bioavailability of the heavy metals in urban soils increased in the order of Cd > Cu > Zn ≈ Pb. Owing to high mobility of Cd and Cu in the urban soils, further investigations are needed to understand their effect on the urban environment and human health. It is concluded that industrial activities and emissions from vehicles may be the major source of heavy metals in urban contamination. Results of this study present a rough guide about the distribution and potential environmental and health risk of heavy metals in the urban soils.  相似文献   

15.
Guiyang is a famous tourist city located in southwestern China. In this study, dust from eleven residential areas, seven city squares, and nine schools was collected to measure the heavy metal levels and evaluate its risk. At each sampling site, 4-5 sub-samples were taken as a bulk sample. All samples were air-dried, ground, passed through a 0.105 mm nylon sieve, digested with HNO3-HC104 to determine the concentrations of Cd, Cu, Ni, Pb and Zn by ICP-MS, and digested with 1：1 aqua regia to determine As by AFS. The results show that the concentrations of As, Cd, Cu, Ni, Pb and Zn in dust of Guiyang City follow normal distribution with means of 16.1, 1.54, 138, 47.7, 129 and 479 mg/kg, respectively. Levels of As, Cd, Cu, Ni, Pb and Zn exceed the background level of soil in Guizhou Province by 33%, 96%, 100%, 78%, 96%, and 100%, respectively. Cd, Cu, Pb and Zn are heavily accumu- lated in dust of living areas with accumulation factors of 4.10, 5.12, 4.12 and 5.51, respectively. City square pos- sesses the highest geometric means of As, Cd, Cu, Pb, and Zn. The risks of heavy metal exposure to teenagers are not obvious and in an order ofAs〉Pb〉Cu〉Ni〉Zn （Cd）.  相似文献   

16.
Mercury emissions during production of blister copper at the smelter Karabashmed are roughly estimated. The high mercury content in the atmospheric dust, soils, lake sediments of the Karabash geotechnogenic system shows that emissions of the plant are the main source of environmental contamination. The mercury content in soils of residential territory ranges within 0.2–11.4 mg/kg, reaching 15 mg/kg in soils of the impact zone. The maximum mercury content in the bottom sediments of Lake Serebry is 32 mg/kg. The high degree of contamination by other elements of emissions (Cu, Pb, Zn, As, Cd) is also demonstrated. Obtained results justify the need for the instrumental control of mercury in emissions.  相似文献   

17.
甘肃嘉峪关市表层土壤重金属空间分布与评价   总被引：1，自引：0，他引：1  
为研究嘉峪关市重金属分布对环境的影响,分析了嘉峪关市表层土壤重金属分布和含量变化,并评价其富集程度,判断其来源和影响因素。采用电感耦合等离子体质谱仪（ICP-MS）测量嘉峪关市134个表层土壤样品中六种重金属元素（Cr、Cd、Cu、Pb、Ni、Zn）的含量,其平均含量分别为281.6 mg/kg、0.35 mg/kg、60.68 mg/kg、51.39 mg/kg、108.65 mg/kg、161.0 mg/kg。在土壤重金属含量空间分布的基础上,用内梅罗指数法和地累积指数法对研究区土壤重金属富集程度进行了评价,六种元素地累积指数排序依次为: Cr > Cd > Pb > Cu > Zn > Ni,各功能区重金属元素整体富集程度依次为工业区 > 戈壁 > 生活区 > 农业区。戈壁采样点重金属元素含量（除Ni外）高于农业区,除工业因素外,地表植被的缺失加剧了戈壁地区重金属元素的富集。结合主成分分析,重金属元素空间展布,及内梅罗指数评价和地累积指数评价,分析了各元素可能的来源,认为Cr、Zn主要来自以钢铁生产加工为主的工业源,Cd、Cu、Pb来自于交通源,Ni可能与钢铁生产或当地背景值有关。通过分析嘉峪关市土壤重金属分布情况,以期为改善当地土壤质量提供科学依据,为我国西北地区土壤重金属的研究提供参考。  相似文献   

18.
A pyrite-rich waste stream is one of three types generated from a kyanite mine in central Virginia near the town of Dillwyn, Buckingham County. Currently, ore consists of approximately 3% pyrite waste and an estimated 382,000 tons of this waste stream has been generated over the past 60 years. The mineralogy of the waste stream consists of variable amounts of pyrite (70–>99%), talc (1–20%), quartz (1–10%), kyanite (0.5–5%) with minor or trace amounts of magnetite, hematite, galena, anorthite and rare earth phosphate. Energy dispersive spectroscopy analysis indicates that talc has minor amounts of Al up to 1.57 wt% and Fe up to 4.29 wt% and pyrite grains have no impurities above detection limit of approximately 0.1 wt%. Bulk chemical analysis of selected elements using inductively coupled plasma-mass spectrometry analysis indicate that Zn (28.82–367.71 ppm), As (8.94–18.26 ppm), Se (44.62–64.50 ppm), Cd (0.19–1.03 ppm), Hg (0.87–35.91 ppm), and Pb (65.10–189.66 ppm) occur at levels of some environmental concern. Au and Ag concentrations are negligible. Currently the waste stream is well managed and sold, but for a low price. Talc is of sufficient quality to be of interest for recycling but the estimated 540 tons generated per year is not a suitable quantity to be economically viable. Currently, the waste stream is not viable for recycling for higher monetary value; however, the characteristics of the pyrite may enable such recycling in the future for solar energy technologies. This and other associated waste streams show long term promise for integrated recycling and may play important economic roles in an economically disadvantaged region.  相似文献   

19.
Agricultural soils of the Riotinto mining area (Iberian Pyrite Belt) have been studied to assess the degree of pollution by trace elements as a consequence of the extraction and treatment of sulphides. Fifteen soil samples were collected and analysed by ICP-OES and INAA for 51 elements. Chemical analyses showed an As–Cu–Pb–Zn association related with the mineralisation of the Iberian Pyrite Belt. Concentrations were 19–994 mg kg−1 for As, 41–4,890 mg kg−1 for Pb, 95–897 mg kg−1 for Zn and of 27–1,160 mg kg−1 for Cu. Most of the samples displayed concentrations of these elements higher than the 90th percentile of the corresponding geological dominium, which suggests an anthropogenic input besides the bedrock influence. Samples collected from sediments were more contaminated than leptosols because they were polluted by leachates or by mining spills coming from the waste rock piles. The weathering of the bedrock is responsible for high concentrations in Co, Cr and Ni, but an anthropogenic input, such as wind-blown dust, seems to be indicative of the high content of As, Cu, Pb and Zn in leptosols. The metal partitioning patterns show that most trace elements are associated with Fe amorphous oxy-hydroxides, or take part of the residual fraction. According to the results obtained, the following mobility sequence is proposed for major and minor elements: Mn, Pb, Cd, > Zn, Cu > Ni > As > Fe > Cr. The high mobility of Pb, Cu and Zn involve an environmental risk in this area, even in soils where the concentrations are not so high.  相似文献   

20.
《Applied Geochemistry》2005,20(8):1533-1545
Spring waters were analysed in the field by anodic stripping voltammetry, using equipment which is sufficiently portable to be useful in a remote heavily forested area accessible by foot only. The equipment and techniques are capable of producing analyses on site to the μg/L level for labile metals. Field analysis avoids issues of sample storage and transport protocols that limit confidence in laboratory measurements of labile elements. Samples were taken as a feedback to immediate analysis resulting in a fine grid map of the geological site. Acid rock drainage emanates from a New Zealand historic mine site, with elevated concentrations of metals. However, ground water and surface water discharging naturally from mineralised rocks in the same area also have elevated levels of metals. This study quantifies natural metalliferous discharges from a single site, and compares this to the overall metal flux from the mine area. Acid (pH 3) metalliferous springs emanate from colluvium and bedrock in a young (months-old) landslide. Labile Cu, Pb, Zn and Cd are the environmentally most significant metals in the studied area. Labile metal concentrations observed in the natural springs are up to 24 μg/L Cu, up to 50 μg/L Pb, up to 5 μg/L Cd and up to 9 mg/L Zn. Labile Cu and Zn concentrations are similar to laboratory-determined total concentrations, whereas labile Pb and Cd concentrations are generally distinctly lower than total Pb and Cd concentrations. Four different spring water compositions occur within metres of each other: acid metalliferous water with high Pb, acid metalliferous water with low Pb, high Cu, Pb, Zn acid water and high pH water with elevated Cu. High metal concentrations in these waters are readily attenuated by adsorption to Fe oxyhydroxides (HFO), especially when rain raises spring water pH at the surface. Copper, Pb and Cd are >99% adsorbed, and Zn >95% adsorbed, during this rainfall dilution. Natural spring waters have potential to contribute up to 10% of the total Zn flux from the catchment, but negligible proportions of Cu, Pb and Cd.  相似文献   

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