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1.
The concentrations of heavy metals (As, Ba, Co, Cr, Cu, Ni, Mo, Pb, Sr, V and Zn) were studied in soils to understand metal contamination due to industrialization and urbanization around Manali industrial area in Chennai, Southern India. This area is affected by the industrial activity and saturated by industries like petrochemicals, refineries, and fertilizers generating hazardous wastes. The contamination of the soils was assessed on the basis of geoaccumulation index, enrichment factor (EF), contamination factor and degree of contamination. Soil samples were collected from the industrial area of Manali from the top 10-cm-layer of the soil. Soil samples were analyzed for heavy metals by using Philips MagiX PRO-2440 Wavelength dispersive X-ray fluorescence spectrometry. The data revealed elevated concentrations of Chromium (149.8–418.0 mg/kg), Copper (22.4–372.0 mg/kg), Nickel (11.8–78.8 mg/kg), Zinc (63.5–213.6 mg/kg) and Molybdenum (2.3–15.3 mg/kg). The concentrations of other elements were similar to the levels in the earth’s crust or pointed to metal depletion in the soil (EF < 1). The high-EFs for some heavy metals obtained in the soil samples show that there is a considerable heavy metal pollution, which could be correlated with the industries in the area. Contamination sites pose significant environmental hazards for terrestrial and aquatic ecosystems. They are important sources of pollution and may result in ecotoxicological effects on terrestrial, groundwater and aquatic ecosystems. In this perspective there is need for a safe dumping of waste disposal in order to minimize environmental pollution.  相似文献   

2.
Environmental geochemical studies were carried out to find out the extent of contamination in sediments due to heavy metals in Balanagar industrial area, Hyderabad, Andhra Pradesh, India. The industrial area consisting of 350 small and large industries manufacturing battery, steel planting, pharmaceutical chemicals, metal plating, etc. The present study was undertaken on sediment contamination in Balanagar industrial area, to determine extent and distribution of heavy metals (Cu, Cr, Ni, Pb, Zn, As) and to delineate the source. There is no treatment plant in the industrial area, and many industries release the effluents into nearby nalas and lakes. Solid waste from the industries is also being dumped along the roads and near the open grounds due to which heavy metals migrate from solid waste to the groundwater. The sediments samples were collected from the study area in clean polythene covers and were analyzed for their heavy metals by X-ray fluorescence spectrometry. The concentration ranges of different heavy metals were Cr, 96.2–439.6 mg/kg; Cu, 95.7–810 mg/kg; Ni, 32.3–13,068.2 mg/kg; Pb, 59.2–512 mg/kg; Zn, 157.1–4,630.5 mg/kg; Co, 1.8–48.3 mg/kg; and V, 35.2–308.5 mg/kg. High concentration of heavy metals in sediments can be attributed to some pharmaceutical and metal industries in the study area. Based on the results obtained, suitable remedial measures can be adopted such as phytoremediation and bio-remediation for reduction of heavy metals in sediments.  相似文献   

3.
Concentrations of trace elements such as As, Ba, Co, Cr, Cu, Ni, Pb, Rb, Sr, V, Y, Zn and Zr were studied in soils to understand metal contamination due to agriculture and geogenic activities in Chinnaeru River Basin, Nalgonda District, India. This area is affected by the geogenic fluoride contamination. The contamination of the soils was assessed on the basis of geoaccumulation index, enrichment factor (EF), contamination factor and degree of contamination. Forty-four soil samples were collected from the agricultural field from the study area from top 10–50 cm layer of soil. Soil samples were analyzed for trace elements using X-ray fluorescence spectrometer. Data revealed that soils in the study area are significantly contaminated, showing high level of toxic elements than normal distribution. The ranges of concentration of Ba (370–1,710 mg/kg), Cr (8.7–543 mg/kg), Cu (7.7–96.6 mg/kg), Ni (5.4–168 mg/kg), Rb (29.6–223 mg/kg), Sr (134–438 mg/kg), Zr (141.2–8,232 mg/kg) and Zn (29–478 mg/kg). The concentration of other elements was similar to the levels in the earth’s crust or pointed to metal depletion in the soil (EF < 1). The high EFs for some trace elements obtained in soil samples show that there is a considerable heavy metal pollution, which could be due to excessive use of fertilizers and pesticides used for agricultural or may be due to natural geogenic processes in the area. Comparative study has been made with other soil-polluted heavy metal areas and its mobility in soil and groundwater has been discussed. A contamination site poses significant environmental hazards for terrestrial and aquatic ecosystems. They are important sources of pollution and may result in ecotoxicological effects on terrestrial, groundwater and aquatic ecosystems.  相似文献   

4.
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   

5.
Due to rapid industrialization, urbanization and intensive agriculture in India increasing contamination of heavy metals in soil has become a major concern. An environmental geochemical investigation was carried out in and around the Pali industrial development area of Rajasthan to determine the effect of contamination in the study area. Soil samples collected near the Pali industrial area were analyzed for Pb, Cr, Cu, Zn, Sr and V contents by using Philips PW 2440 X-ray fluorescence spectrometer. Samples were collected from the industrial area of Pali from the top 10 cm layer of the soil. Most of the samples were collected near small streams adjacent to industrial areas, and near Bandi River. Levels of the metals in soils around the industrial area were found to be significantly higher than their normal distribution in soil such as Pb – 293 mg/kg, Cr – 240 mg/kg, Cu – 298 mg/kg, Zn – 1,364 mg/kg, Sr – 2,694 mg/kg and V – 377 mg/kg. High concentration of these toxic elements in soil is responsible for the development of toxicity in agriculture products, which in turn affects human life. Distribution of metals, their contents at different locations, correlation of heavy metals in soil and their effect on human health are discussed in the paper.  相似文献   

6.
Heavy metals in soils are of great environmental concern, in order to evaluate heavy metal contents and their relationships in the surface soil of industrial area of Baoji city, and also to investigate their influence on the soils. Soil samples were collected from 50 sites, and the concentration of Pb, Zn, Cu, Cr, Ni heavy metals and the contents of characteristics in soil from industrial area of Baoji city were determined with X-ray fluorescence method. The concentrations of Pb, Zn, Cu, Cr and Ni in the investigated soils reached the amount of 2,682.00–76,979.42, 169.30–8,288.58, 62.24–242.36, 91.96–110.54 and 36.14–179.28 mg kg−1, respectively. The major element Pb contents of the topsoils were determined. to highlight the influence of ‘anthropic’ features on the heavy metal concentrations and their distributions. To compare, all values of elements were much higher than those of unpolluted soils in the middle of Shaanxi province that average 16.0–26.5, 67.1–120.0, 17.8–57.0, 46.9–65.6 and 24.7–34.6 mg kg−1 for Pb, Zn, Cu, Cr and Ni, respectively. An ensemble of basic and relativity analysis was performed to reduce the precipitate of Pb in soil was extremely high and greatly relativity with other elements. Meanwhile, Pb, Zn, Cu, Cr, Ni heavy metals were typical elements of anthropic activities sources, so it was easy to infer to the tracers of anthropic pollutions from the factorial analysis, which was coming from the storage battery manufactory pollutions. The pollutant distributions were constructed for the urban area which identified storage battery manufactory soot precipitate as the main source of diffuse pollution and also showed the contribution of the topsoils of industrial area of Baoji city as the source point of pollution. Consequently, the impact of heavy metals on soil was proposed and discussed. These results highlight the need for instituting a systematic and continuous monitoring of heavy metals and other forms of pollutants in Baoji city to ensure that pollution does not become a serious problem in the future.  相似文献   

7.
There is a growing public concern over the potential accumulation of heavy metals in soil, owing to rapid urban and industrial development in the last decade in India. Therefore, an attempt was made to investigate the pollution caused due to excessive accumulation of heavy metals in soils near Thane–Belapur industrial belt of Mumbai. Soil samples were collected from surrounding industrial areas and were analyzed for toxic/heavy metals by X-ray fluorescence spectrometer. The analytical results indicate that the soils in the study area were enriched with Cu, Cr, Co, Ni and Zn. The concentration ranges were: Cu 3.10–271.2 mg/kg (average 104.6 mg/kg), Cr 177.9–1,039 mg/kg (average 521.3 mg/kg), Co 44.8–101.6 mg/kg (average 68.7 mg/kg), Ni 64.4–537.8 mg/kg (average 183.6 mg/kg) and Zn 96.6–763.2 mg/kg (average 191.3 mg/kg). The visualization of spatial data is made by preparing distribution maps of heavy metal concentration in soils and co-relation diagrams. These results highlight the need for instituting a systematic and continuous monitoring of the study area for heavy metals and other forms of pollution to ensure that pollution does not become a serious problem in future.  相似文献   

8.
Consuming edible plants contaminated by heavy metals transferred from soil is an important pathway for human exposure to environmental contaminants. In the past several decades, heavy metal accumulation in contaminated soil has been widely studied; however, few researches investigated the background levels of metals in plants and evaluated the difference in plants grown in soils produced from different parent rocks. In this study, a systemic survey of heavy metal distribution and accumulation in the soil–pepper system was investigated in an unpolluted area, Hainan Island, China. Levels of Cu, Pb, Zn and Cd were measured in soils and pepper fruits from five representative pepper-growing areas with different soil parent rocks (i.e. basalt, granite, sedimentary rock, metamorphic rock and alluvial deposits). Average concentrations of Cu, Pb, Zn and Cd in pepper fruits were 11.52, 0.84, 8.77 and 0.05 mg/kg, respectively. The concentrations of heavy metals in soils are controlled by the parent materials and varied greatly from in different areas. Heavy metal contents in all pepper samples were lower than the Chinese maximum contaminant levels. The relationship between heavy metals in soils and biological absorption coefficient (BAC) of pepper fruits suggests that the uptake ability of pepper for soil metals depends mainly on the physiological mechanism, while in some cases, the soil types and supergene environment are also important.  相似文献   

9.
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   

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.
The long-term industrialization and urbanization of Guangzhou city may lead to heavy metal contamination of its aquatic sediment. Nevertheless, only few studies have been published on the distribution and contamination assessment of heavy metals in this urban river sediment. Thus, the major objective of this study was to quantitatively assess contamination of heavy metals and their chemical partitioning in the sediments of the Guangzhou section of the Pearl River (GSPR). Surface sediment samples were collected at 10 sites in the main river and 12 sites in the creeks of the GSPR. The total content of Cd was determined by graphite furnace atomic adsorption spectrometry (GF-AAS), and content of Cr, Cu, Pb and Zn was determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). The chemical partitioning of these heavy metals in the sediments of the main river was determined by the sequential selective extraction (SSE) method. Results indicated that the average total concentrations of Cd, Cr, Pb, Cu and Zn in the sediments of the main river were 1.44, 63.7, 95.5, 253.6 and 370.0 mg/kg, respectively, whereas they were 2.10, 125.5, 110.1, 433.7 and 401.9 mg/kg in the sediments of the creeks. The sediment at M4 and C9 sites was heavily contaminated with about 8 and 11 of toxic unit, respectively. Cr, Cu, Pb and Zn were mostly bound to organic matter and in the residual phase, whereas Cd was mostly associated with the soluble and exchangeable phase and the residual phase. The mobility and bioavailability of Cd, Zn and Cr in the sediments of the main river were relatively higher than Cu and Pb, due to higher levels in the soluble and exchangeable fraction and the carbonate fraction. The potential acute toxicity in the sediments of the main river and creeks was mainly caused by Cu contamination, accounting for 21.7–37.1% and 16.9–46.3% of the total toxicity, respectively, followed by Zn and Pb. Adverse biological effects induced by heavy metals would be expected in the sediments of the GSPR. Therefore, the sediments of the GSPR, especially at M4 and C9 sites, need to be remediated to maintain aquatic ecosystem health.  相似文献   

12.
In order to avoid the pollution of trace metals in marine environment, it is necessary to establish the data and understand the mechanisms influencing the distribution of trace metals in marine environment. The concentration of heavy metals (Fe, Mn, Cr, Cu, Ni, Pb, Zn, Co and Cd) were studied in sediments of Ennore shelf, to understand the metal contamination due to heavily industrialized area of Ennore, south-east coast of India. Concentration of metals shows significant variability and range from 1.7 to 3.7% for Fe, 284–460 μg g−1 for Mn, 148.6–243.2 μg g−1 for Cr, 385–657 μg g−1 for Cu, 19.8–53.4 μg g−1 for Ni, 5.8–11.8 μg g−1 for Co, 24.9–40 μg g−1 for Pb, 71.3–201 μg g−1 for Zn and 4.6–7.5 μg g−1 for Cd. For various metals the contamination factor (CF) and geoaccumulation index (I geo) has been calculated to assess the degree of pollution in sediments. The geoaccumulation index shows that Cd, Cr and Cu moderately to extremely pollute the sediments. This study shows that the major sources of metal contamination in the Ennore shelf are land-based anthropogenic ones, such as discharge of industrial wastewater, municipal sewage and run-off through the Ennore estuary. The intermetallic relationship revealed the identical behavior of metals during its transport in the marine environment.  相似文献   

13.
Metal fluxes to the sediments of the Moulay Bousselham lagoon,Morocco   总被引：2，自引：0，他引：2  
The metal content in surface sediments (0–2 cm, 26 samples), in a sediment core (120, 1 cm slices), taken from Moulay Bousselham (Morocco) was investigated. Concentrations of Al, Fe, Mn, Pb, Zn, Cu, Ni, Cr, Cd, As, and Hg were evaluated in surface and cored sediments of Moulay Bousselham lagoon. Significantly high concentrations in μg g−1 dw of Pb (31.7–6.2), Zn (758.9–167), Cu (310.7–22), Ni (96–10.5), Cr (113–18.9), Cd (0.84–0.02), As (1–0.1), and Hg (0.61–0.02) were found in sediment samples from Moulay Bousselham lagoon. Calculated enrichment factors [EFMe = (Me/Al)sample/(Me/Al)background], using Al as a normalizer, and correlation matrices showed that metal pollution in Merja Zerga of Moulay Bousselham lagoon was the product of anthropogenic sources, while the metal content in Merja Kehla was of natural origins. The results suggest that a major change in the sedimentary regime of the lagoon, associated with internal trapping and re-distribution of heavy metal, has been occurring in the past few decades. The cause would appear to be the construction of a Nador Canal at the lagoon. Probable effects concentrations (PEC) were often exceeded for heavy metals in the lagoon sediments, especially for Zn, Cu, Ni, and Cr, and four stations, stations MZ-11, MZ-12, MZ-13, MZ-14, MZ-16, and MZ-17, had multiple metals at presumptively toxic levels. These comparisons suggest that sediment metal levels in the river are clearly high and probably pose an environmental risk at some stations. The levels of most of the metals were not greatly enriched, a consideration that is of the utmost importance when contamination issues are at stake. Metal concentrations found in Moulay Bousselham lagoon were comparable to aquatic systems classified as contaminated from other regions of the world.  相似文献   

14.
Simultaneous competitive adsorption behavior of Cd, Cu, Pb and Zn onto nine soils with a wide physical–chemical characteristics from Eastern China was measured in batch experiments to assess the mobility and retention of these metals in soils. In the competitive adsorption system, adsorption isotherms for these metals on the soils exhibited significant differences in shape and in the amount adsorbed. As the applied concentration increased, Cu and Pb adsorption increased, while Cd and Zn adsorption decreased. Competition among heavy metals is very strong in acid soils with lower capacity to adsorb metal cations. Distribution coefficients (K dmedium) for each metal and soil were calculated. The highest K dmedium value was found for Pb and followed by Cu. However, low K dmedium values were shown for Zn and Cd. On the basis of the K dmedium values, the selectivity sequence of the metal adsorption is Pb > Cu > Zn > Cd and Pb > Cu > Cd > Zn. The adsorption sequence of nine soils was deduced from the joint distribution coefficients (K dΣmedium). This indicated that acid soils with low pH value had lower adsorption capacity for heavy metals, resulting in much higher risk of heavy metal pollution. The sum of adsorbed heavy metals on the soils could well described using the Langmuir equation. The maximum adsorption capacity (Q m) of soils ranged from 32.57 to 90.09 mmol kg−1. Highly significant positive correlations were found between the K dΣmedium and Q m of the metals and pH value and cation exchange capacity (CEC) of soil, suggesting that soil pH and CEC were key factors controlling the solubility and mobility of the metals in soils.  相似文献   

15.
 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  相似文献   

16.
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   

17.
Heavy metal contamination was the main environmental problem around the Jinchang Ni–Cu mine area of Gansu, Northwest China. The concentration of heavy metals (Cr, Cu, Ni, Pb, and Zn) in various environmental mediums around the Jinchang Ni–Cu mine area were analyzed using atomic absorption spectrometry (AAS). The different chemical speciation of heavy metals was extracted using BCR (European Community Bureau of Reference) sequential extraction procedure, and the concentration of chemical speciation of each heavy metal was measured by inductively coupled plasma-atomic emission spectrometry. The results showed that Cu and Ni were the most important heavy metal pollutants in various mediums including cultivated soils, dust on slagheap surfaces, tailings, and sediments in waste water drains. In the tailings and sediments, the concentrations of Ni were obviously higher than those of Cu, whereas, in the soil and dust, the concentrations of Cu were higher than those of Ni. Analysis of chemical speciation indicated that Cr and Zn were mainly in residual fraction; Cu was mainly in oxidizable fraction; Ni was mainly in reducible fraction and acid soluble fraction; and Pb was mainly in reducible fraction and residual fraction. The extent of contamination of various environmental mediums was different because the heavy metals were derived from different sources. Furthermore, the mobility of various heavy metals was different because of the different distribution of chemical speciation.  相似文献   

18.
Analysis of the total heavy metal (Cr, Cd, Pb, As, Cu, Ni, Zn, Co) concentration was performed on 33 soil samples taken from different profiles and soil types in a highly urbanized and industrial sector of Addis Ababa, central Ethiopia. They were analyzed using aqua regia extraction coupled with a four-stage sequential extraction (SE) procedure. The objectives of the analysis were to investigate the degree of soil heavy metal contamination, its binding forms, mobility and the implications for the groundwater resource. The results show a relatively high content of the analyzed trace metals in the soil attributed to anthropogenic and geogenic sources. Although most of the trace metals are found in the upper few centimeters of the residual soils, because of churning processes within the black cotton soils, vertical distribution of the trace metals is complex. According to the heavy metal SE analysis, the major heavy metal contribution is from the residual followed by the hydroxide phases. Groundwater heavy metal contamination is present with more than 90 and 50% of the analyzed groundwater samples exceeding WHO guidelines for Cr and Cd, respectively. Since the degree of soil heavy metal contamination has apparently not surpassed the soil’s buffering capacity, it appears that the transport path of these toxic metals to the groundwater is through fractures, joints, and related preferential flow paths.  相似文献   

19.
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   

20.
Surface soil and sediment samples were collected from the surroundings of the Ittehad Chemical Industries Kalashah Kaku industrial zone to assess residual level of 19 organochlorine pesticides (OCPs) and identify their sources. DDTs and HCHs were most prevalent OCPs and general pattern of contamination followed the order: ∑DDT > ∑HCH > dicofol > endrin > heptachlor > dieldrin > endosulfan II. Total measured concentrations of HCHs (6.38–121.71 ng/g) and DDTs (759.65–1811.98 ng/g) were greater in the soil samples collected from fodder/rice fields irrigated with the factory effluents and in the surrounding of waste disposal site. Ratios of β to γ-HCH highlighted an old mixed source of technical HCH and lindane in surface soils. Predominance of p,p′-DDT and p,p′-DDE among isomers and metabolites showed that large quantity of technical grade DDT is still present in the surrounding surface soils. Six soil samples were categorized as heavy polluted soils (class III category of DDT > 1,000 ng/g), two soil samples into less polluted soil between class I and II (50–500 ng/g) and 28 soil samples as non-polluted (<50 ng/g) according to environmental quality standards for surface soils. Six soil samples were categorized as less polluted between class I and II of HCHs (50–500 ng/g). Greater concentration of DDTs and HCHs above quality guideline poses potential exposure risk to biological organisms, safety of agricultural products and human health in the surrounding of the Ittehad Chemical Industries.  相似文献   

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