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1.
Nastja Rogan Tadej Dolenec Todor Serafimovski Goran Tasev Matej Dolenec 《Environmental Earth Sciences》2010,61(5):899-907
Contamination of soils with heavy metals is widespread and poses a long-term risk to ecosystem health. Abandoned and active
mining sites contain residues from ore-processing operations that are characterised by high concentrations of heavy metals.
The distribution and mobility characteristics of heavy metals (As, Cd, Cu, Pb, and Zn) in paddy soil samples from Kočani Field
(Macedonia) using ICP-EAS and a sequential extraction procedure was evaluated. The results indicate that highly elevated concentrations
of As, Cd, Cu, Pb, and Zn were detected in the paddy soil sample from location VII-2 in the vicinity of Zletovo mine and Zletovska
river in the western part of Kočani Field, which drains the untreated acid mine waters and mine wastes from the active Zletovo
mine. The degree of contamination based on index of geoaccumulation (I
geo) from strong to weak in the paddy soils samples is Pb > As > Cd > Zn > Cu. The mobility potential of heavy metals in all
paddy soil samples increases in the order As < Cu < Pb < Zn < Cd. According to the results of the anthropogenic impact on
the paddy soils, a further study on the heavy metal concentrations in rice and other edible crops, the remediation process
of the paddy soils and a dietary study of the local population are needed. 相似文献
2.
Accumulation of heavy metals in wild commercial fish from the Baotou Urban Section of the Yellow River,China 总被引:1,自引:0,他引:1
In this work we studied the accumulation of heavy metals in nine species of fish with different life and feeding habitats
which are native and major commercial fish in the Baotou Urban Section of the Yellow River. The results showed that the concentration
of heavy metals was significantly dependent on fish species; the pollution index of heavy metals in different species were
ranked as Hemiculter leucisclus > Carassius auratus auratus > Hemibarbus maculatus > Megalobrama amblycephala > Abbottina rivularis > Cyprinus carpio > Squaliobarbus curriculus > Perccottus glehni > Saurogobio dabryi. Product–moment correlation coefficients among the metal pairs Pb–Zn, Cu–Cd, Cu–Zn, Cu–Pb, Pb–Cd, and Zn–Cd revealed there
was no competitions between metals in each tissue. Correlations between heavy metal concentrations and fish length or weight
indicated that accumulation of the heavy metals by the different fish species was related to their surrounding environments
and their life and feeding habitats. According to the mean bioconcentration factors (BCFs), the heavy metal concentrations
in these nine species were ranked Zn ≫ Cu > Cd ≈ Pb. In this work, the bioaccumulation factors (BAFs) were developed by using
the sum of exchangeable and bound-to-carbonate heavy metals as Cs values. It was found that BAFs better reveal the accumulation
characteristics of the heavy metals in the fish, which might provide an effective method for assessing bioaccumulation of
heavy metals. 相似文献
3.
Keli Zhao Weiwen Zhang Ling Zhou Xingmei Liu Jianming Xu Panming Huang 《Environmental Earth Sciences》2009,59(3):519-527
Many studies have been conducted on model transfer in soil–plant systems. However, relatively little information is available
on modeling metal transfer in soil–rice system and associated risk assessment in real paddy fields. Based on a random sampling
method from Nanxun, Shengzhou and Wenling in Zhejiang province, China, 15 pairs of rice and the corresponding soil samples
were respectively collected for analysis of heavy metals and soil pH. The results showed that the accumulation ability of
rice for different heavy metals was significantly different (p < 0.05), and was in the order of Cd > Zn > Cu > Ni > Cr > Pb. The relationships of heavy metals in rice with those in soil,
along with soil pH, were well described by linear regression models. Except for Pb, the contents of most metals in rice were
positively correlated with those of the soil. Soil pH was negatively correlated with the contents of Cd, Zn and Ni in rice,
and positively correlated with Pb in rice; however, it had less effect on Cr and Cu. Based on risk reference dose (RfD), the risk assessment data indicated that the rice grown in Zhejiang paddy fields does pose some potential Cd and Cr contamination
risk to food safety; rice in Shengzhou posed light Ni risk. 相似文献
4.
The present study was conducted to investigate the concentrations of heavy metals (HMs) in deep groundwater from coal mining area, including cadmium (Cd), chromium (Cr), copper (Cu), zinc (Zn), lead (Pb), and nickel (Ni). The samples were collected from different aquifers in four coal mines of northern Anhui province, China, which were unconsolidated formation (UF), coal measure aquifer (CA), Taiyuan limestone aquifer (TA), and Ordovician limestone aquifer (OA), respectively. HM concentrations from the four different sources were analyzed by atomic absorption spectrometer, and were found in the order of Zn>Ni>Pb>Cu>Cd>Cr (in UF), Ni>Zn>Pb>Cu>Cr>Cd (in CA), Ni>Zn>Pb>Cu>Cd>Cr (in TA), and Zn>Ni>Pb>Cu>Cr>Cd (in OA), respectively. Concentrations of Cu, Zn, and Cr were found within the quality guidelines set by Bureau of Quality and Technical Supervision of China (GB/T 14848-93) and World Health Organization, while the concentrations of Cd, Pb, and Ni were higher than their respective permissible limits. The enhanced concentrations of Ni, together with Cr, were considered to be affected by anthropogenic sources, since they both had high variable coefficient. Moreover, the inter-dependence of HMs and their pollution sources were further discussed using statistical techniques, including one-factor analysis of variance, Pearson correlation analysis, and principle component analysis. 相似文献
5.
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
6.
Distribution of Cd,Pb, Zn and Cu and their chemical speciations in soils from a peri-smelter area in northeast China 总被引:2,自引:0,他引:2
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
7.
Donald L. Suarez 《Geochimica et cosmochimica acta》1976,40(6):589-598
Soils of loamy sand on weathered, sandy dolomite were cored from six holes up to 70 ft beneath a municipal waste landfill in central Pennsylvania. Mn, Fe, Ni, Co, Cu, Zn, Cd, Pb, and Ag were determined in exchangeable and non-exchangeable forms in total and < 15 μm soil samples. Most of these metals were bound in Mn oxides, non-exchangeable with 0.5 M CaCl2. The Mn oxides (often X-ray amorphous) identified when crystalline as todorokite occurred chiefly as coatings on quartz grains.Somewhat higher amounts of acid leachable trace metals were found in the < 15 μm size fraction than in the total soil samples; however, trace metal/Mn ratios were similar in both. In general, the initial mild soil leaching, which dissolved chiefly Mn oxides, gave MnFeX>Co>Ni>Pb>Zn> Cu>Cd>Ag. The final leaching, which dissolved chiefly ferric oxides, gave Fe>Mn>Ni>Zn>Co> Cu>Pb>Cd>Ag. Samples taken from an unpolluted site and from the same soils affected for seven years by leachate from the refuse had similar metal contents.Soil extractable Co, Ni, Cu, and Zn could be predicted from the Mn extracted. Based in part on factor analysis of the data, Mn-rich oxides had at least tenfold higher heavy metal percentages than Fe-rich oxides (crystalline component goethite), reflecting their greater coprecipitation potential. Because of this potential and because of the generally higher solubility of Mn than Fe oxides, more heavy metals may be released from Mn-rich than from Fe-rich soils by disposal of organic-bearing wastes. However, leaching of the moisture-unsaturated soils in situ is rarely severe enough to completely dissolve both Mn and Fe oxides. Based on the Mn content, Cd, Cu, and Pb were depleted in soil moisture beneath the landfill relative to their amounts in the soil. This depletion may reflect factors including heterogeneity in metal content of the soil oxides; preferential resorption of these metals; and removal of the Cd, Cu, and Pb as organic precipitates or as inorganic precipitates such as carbonates. 相似文献
8.
Contamination and potential mobility assessment of heavy metals in urban soils of Hangzhou,China: relationship with different land uses 总被引:1,自引:0,他引:1
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
9.
Heavy metals in freshly deposited sediments of the Gomati River (a tributary of the Ganga River): effects of human activities 总被引:10,自引:0,他引:10
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 相似文献
10.
C. M. A. Iwegbue F. E. Egobueze K. Opuene 《International Journal of Environmental Science and Technology》2006,3(2):167-172
This communication presents the results of preliminary investigation of the characteristic levels of heavy metals in surface soils of an oilfield in the Niger Delta. The results indicate higher concentration of the following metals: Cd, Pb, Cu; Ni, Zn, Cr, Mn and Hg in soils around the gas plant than the pipeline areas. There is a significant temporal and spatial variation in the concentrations of the heavy metals. Samples collected during the wet season showed lower concentrations of heavy metals. The distribution pattern of heavy metals follows the following order Fe> Mn> Zn> V> Cr> Pb> Cu> Ni> Cd> Hg> As. The soils around the oilfield could be considered unpolluted since the concentrations of the metals fit into background levels and concentrations found in natural and agricultural soils. Since metal build up is a gradual process, farmland, fishing ponds and water bodies closer to these facilities will be at risk of heavy metal pollution over time. 相似文献
11.
Assessment of heavy metal accumulation in macrophyte, agricultural soil, and crop plants adjacent to discharge zone of sponge iron factory 总被引:1,自引:0,他引:1
The present study deals with the characterization of effluent released from sponge iron industries and distribution of heavy
metals in soil and macrophytes near to effluent discharge channel. Apart from this, accumulation of heavy metals in nearby
soil and vegetation system irrigated with effluent-contaminated water is also the subject of this study. Physico-chemical
analysis of effluent reveals that the concentration of total suspended solids (TSS), total hardness (TH), iron (Fe2+), and oil and grease are greater than the IS (1981) norms for discharge of water into inland water body. The soil along the sides of the effluent channel also shows higher
concentration of heavy metals than the background soil. The enrichment of the heavy metals are in the order of Chromium (Cr) > Iron
(Fe) > Manganese (Mn) > Zinc (Zn) > Copper (Cu) > Cadmium (Cd). Macrophytes growing along the sides of the effluent channel
also show significant accumulation of heavy metals almost in the same order as accumulated in soil. Higher uptake of heavy
metals by these varieties reveals that these species can be used for future phytoremediation. The effluent as well as contaminated
water is extensively used for irrigation for growing vegetables like tomato (Lycopersicon esculatum) in the surrounding areas. Heavy metal accumulation in this agricultural soil are in the sequence of Cr > Fe > Mn > Zn > Cu > Cd.
More or less similar type of accumulation pattern are also found in tomato plants except Fe and Zn exceeding Cr and Mn. Transfer
Factor of heavy metals from soil to tomato plants (TFS) shows average value of <1, suggesting less uptake of heavy metals from soil. Among the plant parts studied, fruit shows
least accumulation. Although tomato plants show some phenotypic changes, the survival of tomato plants as well as least accumulation
of metals in fruit reveals their tolerance to heavy metals. Therefore it may be suggested that this plant can be grown successfully
in the heavy metal contaminated soil. Further research work on in situ toxicity test will be necessary in order to identify
the most resistive variety on this particular type of contaminated site. 相似文献
12.
Distribution and speciation of heavy metals and their sources in Kumho River sediment,Korea 总被引:1,自引:1,他引:0
The interaction between heavy metals and river sediment is very important because river sediment is the sink for heavy metals
introduced into a river and it can be a potential source of pollutants when environmental conditions change. The Kumho River,
the main tributaries of the Nakdong River in Korea, can be one of the interesting research targets in this respect, because
it runs through different geologic terrains with different land use characteristics in spite of its short length. Various
approaches were used, including mineralogical, geochemical, and statistical analyses to investigate the distribution and behavior
of heavy metals in the sediments and their sources. The effect of geological factor on the distribution of these metals was
also studied. No noticeable changes in the species or relative amounts of minerals were observed by quantitative X-ray diffraction
in the sediments at different stations along the river. Only illite showed a significant correlation with concentrations of
heavy metals in the sediments. Based on an average heavy metal concentration (the average concentrations of Cd, Co, Cr, Cu,
Ni, Pb, and Zn were 1.67, 20.9, 99.7, 125, 97.6, 149, 298 ppm, respectively), the sediments of the Kumho River were classified
as heavily polluted according to EPA guidelines. The concentrations of heavy metals in the sediments were as follows: Zn > Pb > Cu > Ni > Cr > Co > Cd.
In contrast, contamination levels based on the average I
geo (index of geoaccumulation) values were as follows: Pb > Cd > Zn > Cu > Co = Cr > Ni. The concentrations of heavy metals increased
downstream (with the exception of Cd and Pb) and were highest near the industrial area, indicating that industrial activity
is the main factor in increasing the concentrations of most heavy metals at downstream stations. Sequential extraction results,
which showed increased heavy metal fractions bound to Fe/Mn oxides at the downstream stations, confirmed anthropogenic pollution.
The toxicity of heavy metals such as Ni, Cu, and Zn, represented by the exchangeable fraction and the fraction bound to carbonate,
also increased at the downstream stations near the industrial complexes. Statistical analysis showed that Pb and Cd, the concentrations
of which were relatively high at upstream stations, were not correlated with other heavy metals, indicating other possible
sources such as mining activity. 相似文献
13.
Retention ponds have been dug along some of the motorways in France to minimize environmental pollution by keeping pollutants
from spreading over the surrounding area. In the current work, eight core samples were collected from the bottom of a retention
pond located along the A-71 motorway in Sologne to study the pollution of sediment by heavy metals and their diagenetic behaviour.
The vertical concentration profiles of metals (Pb, Zn, Cd, Fe and Mn) in sediment as well as in interstitial water were determined.
Especially in the case of the sediment, a sequential extraction method was employed to investigate how the movement of each
metal is associated with the other metals and with other solid phases such as organic matter. In addition, to investigate
the relative mobility of the metals, the distribution coefficients (KD) were also determined. The concentrations of the metals were always found to be highest in the topmost layer of sediment.
This so-called surface enrichment is caused by a substantial increase of the non-detrital fraction of these metals at the
sediment surface. For instance, the accumulation of Pb and Zn is associated with the increase in the "fraction II" in the
sequential extraction. The accumulation of Cd at the surface (0–2 cm) is partly due to the liberation of Cd from the particles
during early diagenesis. However, the major factor contributing to the accumulation of Cd at the sediment surface is attributed
to the dissolution of Cd from polluted roadside soil during the periods of rainstorms and its subsequent redeposition on the
sediment surface after being carried to the retention pond. KD values for Zn and Cd were found to decrease with depth, while KD values for Pb increased. Based on the KD values, the relative mobilities of the studied metals were determined to be as follows: Mn>Zn>Cd>Pb, for the upper layer,
and Mn>Cd>Zn>Pb, for the layers below.
Received: 28 October 1996 / Accepted: 21 November 1996 相似文献
14.
The presence of heavy metal concentrations was examined in natural sediments from four sites along the Jajrood river in northeast
of Tehran, the capital of Iran. Besides determination of elemental concentrations (Pb, Cu, Zn, Cd, Ni and Cr), X-ray fluorescence
and X-ray diffraction tests were carried out to determine other chemical components in these adsorbents. Also the ability
of sediments to adsorb these heavy metal ions from aqueous solutions was investigated. Results show that the extent of adsorption
increases with increase in adsorbent concentration. The amount of adsorbed Pb, Cu and Zn in sediments was much greater than
that of the other metals, and Cr was adsorbed much less than others. The adsorbabilities of sediments to heavy metals increased
in the order of Pb > Cu > Zn > Cd > Ni > Cr. Based on the adsorption data, equilibrium isotherms were determined at selected
areas to characterize the adsorption process. The adsorption data followed Freundlich and Langmuir isotherms in most cases.
Correlation and cluster analysis was performed on heavy metals adsorption and sediment components at each site to evaluate
main adsorbing compounds in sediments for each metal. Results demonstrated that heavy metals sorption is mostly related to
load of organic matter in the Jajrood river sediments. 相似文献
15.
D. Ciszewski 《Environmental Geology》1997,29(1-2):50-57
The influence of sources of effluents on pollution of bottom sediments of the small Chechło River (23 km long, mean discharge
1.5 m3 s–1) in southern Poland was examined through analysis of heavy metals distribution in transverse and longitudinal cross sections.
Underground waters from a Pb–Zn mine cause very high concentrations of Zn, Cd, and Pb in both fractions investigated (<1 mm
and <0.063 mm) of sediments in the active channel zone, whereas sedimentation of huge amounts of suspended matter discharged
from oil refinery cause concentrations of heavy metals in fine fractions rather uniform in cross sections. In the lowest reach,
with relatively reduced contamination, the highest concentration both in fine and coarse fractions occurs close to the river
banks and in the deepest points of the channel. The lowest concentrations have been found at the points of strongest reworking
and accumulation of sandy material in the riverbed.
Received: 25 April 1995 · Accepted: 11 September 1995 相似文献
16.
The study area covers two geologically different regions which have intensively been carpeted by tea plants in the eastern
Black Sea. The rocks exposed in the region contain considerable amount of trace metals due to Upper Cretaceous massive sulfide
formations and tertiary epithermal mineralizations. Tea plants that grow in soils derived from such mineralized rocks contain
different concentrations of Cu, Pb, Zn, Fe, Cd, P, Al, Na, K, and S. The content ratios of most of the analyzed elements except
Al are higher in basaltic and sedimentary rocks. To describe the transfer of metals from soil to tea leaf, the Freundlich-type
model (log c
plant = ac
soil + log b) is used. The metal concentrations in leaves of tea plant in the studied soils are ranked as Zn > Cu > Pb > Al > Cd > Fe.
The capacity of the plant to affect the metal accumulation decreased as follows: Fe > Cd > Pb > Cu > Zn > Al. Negative correlations
were found between pH and availability of Cu, Pb, Zn, Mn, and Al elements by the tea plant. Experimental applications indicated
that tea plant leaves growing on soils with high metal contents show some signs of toxicity. In soils where, particularly,
ammonium sulfate fertilizer is used, metal uptake by the tea plant was found to be significantly higher as a result of extremely
acidic character of the soil. 相似文献
17.
Contamination,chemical speciation and vertical distribution of heavy metals in soils of an old and large industrial zone in Northeast China 总被引:5,自引:0,他引:5
Fayun Li Zhiping Fan Pengfei Xiao Kokyo Oh Xiping Ma Wei Hou 《Environmental Geology》2009,57(8):1815-1823
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. 相似文献
18.
The total concentrations and oral bioaccessibility of heavy metals in surface-exposed lawn soils from 28 urban parks in Guangzhou were investigated, and the health risks posed to humans were evaluated. The descending order of total heavy metal concentrations was Fe > Mn > Pb > Zn > Cu > Cr > Ni > Cd, but Cd showed the highest percentage bioaccessibility (75.96%). Principal component analysis showed that Grouped Cd, Pb, Cr, Ni, Cu and Zn, and grouped Cr and Mn could be controlled two different types of human sources. Whereas, Ni and Fe were controlled by both anthropogenic and natural sources. The carcinogenic risk probabilities for Pb and Cr to children and adults were under the acceptable level (<1 × 10−4). Hazard Quotient value for each metal and Hazard Index values for all metals studied indicated no significant risk of non-carcinogenic effects to children and adults in Guangzhou urban park soils. 相似文献
19.
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
20.
Distribution patterns of some heavy metals in the surface sediment fractions at northern Safaga Bay, Red Sea, Egypt 总被引:2,自引:0,他引:2
Mahmoud A. Dar 《Arabian Journal of Geosciences》2014,7(1):55-67
The distribution patterns, the index of geo-accumulations (MIgeo), and the enrichment ratios (ER n ) of the contaminant metals: Fe, Mn, Zn, Cu, Pb, and Ni were studied in gravel, sand, mud, coarse, medium, and fine sediment fractions of the uppermost layer of the bottom sediments collected from 12 stations covering the northern part of Safaga Bay. The distribution levels of these metals were increasing with grain size decreasing toward the central axis of the bay that extends NE–SW and southward to Safaga Harbour indicating that these metals concentrated mainly in the fine, very fine, and particulate fractions of sediments and to many anthropogenic sources. The geo-accumulation factor of Zn was more significant (MIgeo?≈?0.62–4.23) relative to the other metals. The bay was classified as moderately to strongly polluted by Zn while it is unpolluted to moderately polluted with the other metals with accumulation sequence of: Zn>Ni>Cu>Mn≥Pb. Zn and Ni recorded the highest enrichment ratios (average ERZn?≈?3.07 to 8.89; average ERNi?≈?0.84 to 3.63) in the different sediment fractions relative the other metals. These enrichment ratios classified the bay as minimal enrichment, suggestive of no or minimal pollution, to significant enrichment, suggestive of a significant pollution signals with metals sequence of: Zn>Ni>Cu>Pb>Mn. 相似文献