The concentrations of eight heavy metals （Cu, Zn, Pb, Cd, Cr, Ni, Hg, and As） in the intertidal surface sediments from Quanzhou Bay were determined to evaluate their levels and spatial distribution due to urbanizati...The concentrations of eight heavy metals （Cu, Zn, Pb, Cd, Cr, Ni, Hg, and As） in the intertidal surface sediments from Quanzhou Bay were determined to evaluate their levels and spatial distribution due to urbanization and economic development of Quanzhou region, southeast China. The ranges of the measured concentrations in the sediments are as follows： 24.8-119.7 mg/kg for Cu, 105.5-241.9 mg/kg for Zn, 34.3-100. 9 mg/kg for Pb, 0.28-0. 89 mg/kg for Cd, 51.1-121.7 mg/kg for Cr, 16.1-45.7 mg/kg for Ni, 0.17-0.74 mg/kg for Hg, and 17.7-30.2 mg/kg for As. The overall average concentrations of above metals exceed the primary standard criteria but meet the secondary standard criteria of the Chinese National Standard of Marine Sediment Quality. Several contents of Cu and Hg exceed the secondary standard criteria at some stations. The results of geoaccumulation index （Igeo） show that Cd causes strong pollution in most of the study area. There are no significant correlations among most of these heavy metals, indicating they have different anthropogenic and natural sources. Some locations present severe pollution by heavy metals depending on the sources, of which sewage outlets, aquatic breeding, and commercial ports are the main sources of contaminants to the area.展开更多
Source apportionment studies of TSP （atmospheric particulate matter with aerodynamic diameters ≤ 100 μm） and PM10 （atmospheric particulate matter with aerodynamic diameters ≤ 10 μm） have revealed that soil dus...Source apportionment studies of TSP （atmospheric particulate matter with aerodynamic diameters ≤ 100 μm） and PM10 （atmospheric particulate matter with aerodynamic diameters ≤ 10 μm） have revealed that soil dust is an important source of these particulates in China. In this study, the contamination of soil dust was assessed through the use of a geoaccumulation index （Igeo）. The mass concentration profiles of 17 elements （Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Br, Ba, and Pb） were established for urban soil dusts. Geochemical compositions of soils from 15 cities were used to represent background urban soil compositions. The results of this study indicated that a number of cities are severely polluted by particulates containing Ca, Cr, Ni, and Cu in both size fractions （TSP and PM10）. Contamination with Zn, Pb, Co, and Br was moderate to severe （Igeo 〉 2）. The Al and Fe concentrations were not high enough for them to be considered contaminants.展开更多
This study focused on the concentration change of heavy metals of sediment cores in heavily polluted north area and less polluted middle area of Fuxian Lake in Southwest China.On the basis of the analysis of Cu,Ni,Ti,...This study focused on the concentration change of heavy metals of sediment cores in heavily polluted north area and less polluted middle area of Fuxian Lake in Southwest China.On the basis of the analysis of Cu,Ni,Ti,V,Pb,Cd,and Zn concentration-depth profiles,the pollution history of heavy metals was studied using 137cesium(137Cs) dating.The sources of heavy metals were distinguished by normalization of their profiles to aluminum and analysis of heavy metal concentrations of potential source materials.Geoaccumulation index(Igeo) was used to quantify their contamination intensity.The results showed that all the heavy metals found in the Fuxian Lake sediments originated naturally before 1980s.Cu,Ni,Ti,and V were still mainly natural in the north lake after 1980s,Cu,Ni,Ti,V,and Pb were mainly natural in the middle lake at all time,but the concentrations of Pb and Zn in the north lake were influenced by industrial wastes from the phosphorus fertilizer factory and cement plants.In all the lake,the contaminations of Cd and Zn were the results of agricultural cultivation using a large amount of fertilizers and the atmospheric fallouts of dusts from cement plants.At present,the geoaccumulation indices showed that the Fuxian Lake sediments were moderately to strongly polluted by Cd in the middle lake,and unpolluted to moderately polluted by Pb and Zn and strongly polluted by Cd in the north lake.Moreover,the pollution intensities of Cd,Zn,and Pb have been increased since 1980s.展开更多
The pollution characteristics of Pb, Cd, Zn, Cu and Ni in soil of lead-zinc mining area were studied. The results indicate that the contamination degree followed the sequence of Cd〉Pb〉Zn〉Ni〉Cu and concentrations o...The pollution characteristics of Pb, Cd, Zn, Cu and Ni in soil of lead-zinc mining area were studied. The results indicate that the contamination degree followed the sequence of Cd〉Pb〉Zn〉Ni〉Cu and concentrations of Pb, Cd and Zn exceeded corresponding limits of the Chinese National Soil Environmental Quality Standard III. The soil was extremely polluted by Cd（Iego=5.26）, moderately to heavily polluted by Zn（Iego=2.38）, heavily to extremely polluted by Pb（Iego=4.13）. The results of BCR three-step sequential extraction procedure show that the active Cd, Pb and Zn were relatively high and might exert adverse effects on the plants grown in the soil, while Cu and Ni existed in soil with a relatively stable form. Potential ecological risk results indicate that soils were engaging in a high potential ecological risk by pollution of Cd and should be given rise to concern.展开更多
Soil contamination by heavy metals is a problem in agricultural irrigation systems.To assess the accumulation and sources of heavy metals in the Yongji irrigation district of the Hetao area,Inner Mongolia,China,195 so...Soil contamination by heavy metals is a problem in agricultural irrigation systems.To assess the accumulation and sources of heavy metals in the Yongji irrigation district of the Hetao area,Inner Mongolia,China,195 soil samples from 39 sites(0–100 cm)were collected,and Zn,Cu,Pb,Cr,and Cd concentrations were analyzed.The mean concentrations were 107.17,32.48,12.31,53.53,and 0.22 mg kg-1,respectively,with no significant differences between soil depths(P>0.05).Concentrations of Zn,Cu,and Cd were higher than the background levels,with moderate accumulation;the contamination factor(CF)values were 1.9,1.7,and 1.9,respectively,and the geoaccumulation index(Igeo)was>0.Concentrations of Pb and Cr were lower than,or close to,the background levels(CF<1,Igeo<0),indicating that they originated from a natural source.The monomial potential ecological risk index(Eri)for Zn,Cu,Pb,and Cr was low;Eri for Cd was 55.73,implying a moderate risk.The grade of potential ecological risk index of the five heavy metals(RI)was low,declining from south to north.The studied soils were contaminated with Zn,Cu,and Cd;principal component(PC)analysis implicated the enrichment of Cd and partial Cu(high loading in PC 2)was related to agricultural activities;Zn and partial Cu,closely associated with PC 3,may have originated from irrigation water from the Yellow River.Future agricultural development should focus on fertilizer and pesticide application and the quality of irrigation water.展开更多
The resource development and changes of hydrological regime, sediment and water quality in the Mekong River basin have attracted great attentions. This research aimed to enhance the study on transboundary pollution of...The resource development and changes of hydrological regime, sediment and water quality in the Mekong River basin have attracted great attentions. This research aimed to enhance the study on transboundary pollution of heavy metals in this international river. In this study, eight sampling sites were selected to collect the bed sand samples along the mainstream of the Mekong River. In addition, the contents of 5 heavy metal elements and their spatial variability along the mainstream of the river were analyzed. The geoaccumulation index （l^eo） and potential ecological risk analysis were employed to assess heavy metal pol- lution status in the mainstream of the Mekong River. The results show that the average con- tent of the heavy metal elements Zn is 91.43 mg/kg, Pb is 41.85 mg/kg, and As is 21.84 mg/kg in the bed sands of the Upper Mekong River, which are higher than those （Zn 68.17 mg/kg, Pb 28.22 mg/kg, As 14.97 mg/kg） in the Lower Mekong. The average content of Cr in the Lower Mekong is 418.86 mg/kg, higher than that in the Upper Mekong （42.19 mg/kg）. Luang Prabang has a very high Cr concentration with 762.93 mg/kg and Pakse with 422.90 mg/kg. The concentration of Cu in all of the 8 sampling sites is similar, except for in Jiajiu with 11.70 mg/kg and Jiebei with 7.00 mg/kg. The results of the geoaccumulation index reveal that contaminations caused by Zn and Pb while Pb and As are more than those by Zn in Upper Mekong. Cr is the primary pollutant in the Lower Mekong, especially at Luang Prabang and Pakse. Slight pollution with As also occurs in Pakse. The potential ecological risk index indi- cates that the potential ecological risk of heavy metals in the mainstream of the Mekong River is low. We argue that the pollution of water quality and contamination of heavy metals in bed sediment caused by mining of mineral resources or geochemical background values in the Mekong is not transmitted from the Upper to the Lower Mekong because of the reservoir sedimentation and dilution along the river.展开更多
Introduction:In this study,metal pollution and their sources in surface soils were evaluated by pollution indices and multivariate statistical techniques in association with a geographical information system(GIS).Meth...Introduction:In this study,metal pollution and their sources in surface soils were evaluated by pollution indices and multivariate statistical techniques in association with a geographical information system(GIS).Methods:Surface soil samples were collected in dry season from different locations of Dhaka Aricha highway and analyzed by energy dispersive X-ray fluorescence(EDXRF).Results:Thirteen different metals were found in the tested samples.Pollution indices are determined by enrichment factor in an order of Zr>Sn>P>Mn>Zn>Rb>Fe>Ba>Sr>Ti>K>Ca>Al.The resulting geoaccumulation index(Igeo)value shows the following order:Sn>Zr>P>Mn>Zn>Rb>Fe>Ba>Ti>Sr>K>Ca>Al.Contamination factors(CFs)of the metals range from 1.422 to 3.979(Fe);0.213 to 1.089(Al);0.489 to 3.484(Ca);1.496 to 2.372(K);1.287 to 3.870(Ti);2.200 to 14.588(Mn);5.938 to 56.750(Zr);0.980 to 3.500(Sr);2.321 to 4.857(Rb);2.737 to 6.526(Zn);16.667 to 27.333(Sn);3.157 to 16.286(P);and 0.741 to 3.328(Ba).Pollution load index calculated from the CFs indicates that soils are strongly contaminated by Zr and Sn.Principal component analysis(PCA)of parameters exhibits three major components.R-mode cluster analysis reveals three distinct groups in both site and metal basis clustering that shows a similar pattern with the PCA.Conclusions:These results might be helpful for future monitoring of further increase of heavy metal concentrations in surface soils along highways.展开更多
Daba Mountain area is one of the two endemic selenosis areas in China,which may relate with the environmental behaviors of selenium (Se) in soil.This study focuses on the concentraion and distribution of Se and its re...Daba Mountain area is one of the two endemic selenosis areas in China,which may relate with the environmental behaviors of selenium (Se) in soil.This study focuses on the concentraion and distribution of Se and its relationships with some other elements in natural soil in the area.The average concentration of Se in Daba Mountain soils was 14.3 times higher than the value cited for natural soil background worldwide,suggesting that soils in the region were contaminated by the element.The finding was confirmed...展开更多
A total of 52 soil samples of Hohhot City were collected and four heavy metals and eight organochlorine pesticides were analyzed. The results showed that Cr, Cu, Zn, and Pb in soil were in range of 20.54 - 48.15 mg/kg...A total of 52 soil samples of Hohhot City were collected and four heavy metals and eight organochlorine pesticides were analyzed. The results showed that Cr, Cu, Zn, and Pb in soil were in range of 20.54 - 48.15 mg/kg, 40.10 - 94.60 mg/kg, 35.14 - 110.48 mg/kg, 38.86g - 245.36 mg/kg, with a mean value of 37.24 mg/kg, 60.76 mg/kg, 80.49 mg/kg, and 145.99 mg/kg, respectively. The high degree of variation of Pb, Zn, and Cu, reflected that the heavy metals were mainly interfered by human factors. The content values of ∑DDTs ranged from 5.01 ng/g to 105.08 ng/g with a mean of 36.94 ng/g, while the ∑HCHs ranged from 6.52 ng/g to 48.65 ng/g with an average of 23.29 ng/g, indicated that DDTs were highly used than HCHs in the study area. The relatively low α-HCH/γ-HCH ratio and relatively high o,p’-DDT/p,p’-DDT ratio indicated the application of lindane and dicofol on regional agricultural soil. The mean Igeo values was Pb (2.9) > Cu (1.5) > Cr (-0.31) > Zn (-0.35), revealing that the soil in Hohhot City was not polluted by Cr and Zn (Igeo 0), moderate polluted by Cu (1 Igeo 2), moderate to heavy pollution by Pb (2 Igeo 3). The range of potential ecological risk index of metals was from 35.02 to 132.96, indicating low to moderate potential ecological risk. HCHs in all soil samples were less than 50 ng/g, which could be considered as unpolluted, while DDTs in several samples were between 50 and 500 ng/g, which could be regarded as having low pollution.展开更多
Soil characterization and heavy metals in different layers (0 - 15 cm;15 - 30 cm and 30 - 45 cm depth) of automobile mechanic waste dumps were studied. The soils showed remarkably high levels of all the metals above b...Soil characterization and heavy metals in different layers (0 - 15 cm;15 - 30 cm and 30 - 45 cm depth) of automobile mechanic waste dumps were studied. The soils showed remarkably high levels of all the metals above background concentrations with most (Ni, Cu, Fe, Cr and Cd) decreasing with soil depth. The distribution pattern were in the following order Fe > Cu > Zn > Pb > Cr > Ni > Cd. Across all the sampling locations and profiles, Fe and Cd showed the highest (476.4 μg·g-1) and least (37.5 μg·g-1) mean concentrations respectively. Pollution load index (PLI) and index of geoaccumulation (Igeo) revealed overall high and moderate contamination respectively but the enrichment factors (EFs) for Pb Ni and Cd are severe. The inter-element relationship revealed the identical source of elements in the soils of the studied area. The accuracy of the results has been cheeked using the standard reference material;SRM (PACS-2). The mechanic waste dumps represent potential sources of heavy metal pollution to environment. The elevated levels of heavy metals in these soil profiles constitute a serious threat to both surface and groundwater.展开更多
In order to investigate distributions of heavy metal pollution in Quanzhou Bay wetland, the total concentration and chemical partitioning of a number of heavy metals （Cu, Zn, Cd, Pb, Cr, Hg） in sediments of three sa...In order to investigate distributions of heavy metal pollution in Quanzhou Bay wetland, the total concentration and chemical partitioning of a number of heavy metals （Cu, Zn, Cd, Pb, Cr, Hg） in sediments of three sampling sites of Quanzhou Bay wetland and their availability to Suaeda australis were analyzed. The Geoaccumulation Index （Igeo） values reveal that the sediments of three sampling sites may all be considered as moderately contaminated for Pb and Zn, and all sediments might be strongly contaminated with cadmium. The partitioning analyses revealed the measured heavy metals in three sites are bound to the exchangeable fraction at lower concentrations. The measured metals in a considerable amount are bound to the reducible and oxidizable fractions, and a high proportion of the measured heavy metals were distributed in the residual fraction in the sediment samples. The concentrations of Cd in each chemical phase extracted from the sediments are above natural global background levels and should be further investigated because of its toxicity. Suaeda australis has different accumulation abilities for the measured heavy metals. For the root and stem, the bioaccumulation ability assessed by bioaccumulation factor （BAF） for the measured heavy metals follows the decreasing order as： Cu〉Cr〉 Zn〉Cd, Pb, Hg. In the leaf, stronger bioaccumulation ability for Hg is exhibited. The heavy metal concentrations in Suaeda australis roots have positive correlations with their available fractions, while the exchangeable fraction of Cu and Cd might have be more important to both mature plant roots and seedling roots uptake than other fractions; as for Cr, the oxidizable fraction might make a greater contribution to the plant root uptake; as for Zn, the reducible fraction might make so contribution ; and for Pb, the oxidizable fraction might make a significant contribution to the mature plant root uptake, however, the exchangeable fraction might have a significant contribution to the seedling root uptake.展开更多
In Tunisia,water scarcity is only adding pressure on water demand in agriculture.In the context of sustainable development goals,Tunisia has been reusing treated wastewater(TWW)as a renewable and inexpensive source fo...In Tunisia,water scarcity is only adding pressure on water demand in agriculture.In the context of sustainable development goals,Tunisia has been reusing treated wastewater(TWW)as a renewable and inexpensive source for soil fertigation and groundwater(GW)recharge.However,major risks can be expected when the irrigation water is of poor quality.This study aims for evaluating the potential risk of TWW and GW irrigation on soil parameters.Accordingly,we evaluated the suitability of water quality through the analysis of major and minor cations and anions,metallic trace elements(MTEs),and the sodium hazard by using the sodium adsorption ratio(SAR)and the soluble sodium percentage(SSP).The risk of soil sodicity was further assessed by SAR and the exchangeable sodium percentage(ESP).The degree of soil pollution caused by MTEs accumulation was evaluated using geoaccumulation index(Igeo)and pollution load index(PLI).Soil maps were generated using inverse spline interpolation in ArcGIS software.The results show that both water samples(i.e.,TWW and GW)are suitable for soil irrigation in terms of salinity(electrical conductivity<7000μS/cm)and sodicity(SAR<10.00;SSP<60.00%).However,the contents of PO_(4)^(3-),Cu^(2+),and Cd^(2+)exceed the maximum threshold values set by the national and other standards.Concerning the soil samples,the average levels of SAR and ESP are within the standards(SAR<13.00;ESP<15.00%).On the other hand,PLI results reveal moderate pollution in the plot irrigated with TWW and no to moderate pollution in the plot irrigated with GW.Igeo results indicate that Cu^(2+)is the metallic trace element(MTE)with the highest risk of soil pollution in both plots(Igeo>5.00),followed by Ni^(2+)and Pb^(2+).Nevertheless,Cd^(2+)presents the lowest risk of soil pollution(Igeo<0.00).Statistical data indicates that Ca^(2+),Na+,Ni^(2+),and Pb^(2+)are highly distributed in both plots(coefficient of variation>50.0%).This study shows that the use of imagery tools,such as ArcGIS,can provide important information for evaluating t展开更多
Surface sedimental samples were collected from(1)Le An River in Jiangxi Province, south of China,and(2)several lakes located in southwest of Germany.Concentrations of heavy metals in these samples were determined.More...Surface sedimental samples were collected from(1)Le An River in Jiangxi Province, south of China,and(2)several lakes located in southwest of Germany.Concentrations of heavy metals in these samples were determined.Moreover,the situations of heavy metal pollution in two regions were comprehensively assessed by combined index of geoaccumulation with visualized multi- variate graphical method——modified Chernoff Face Graph.Face graphs intuitively demonstrated strong heavy metal contamination in Le An River,especially copper pollution.However,in lakes' sedimental samples,contamination of other heavy metals showed mild or clean except cadmium and chromium.展开更多
Gold mining is now widely acknowledged as one of the significant sources of soil pollution in developed countries. In developing countries, the sources and levels of soil contamination have not been thoroughly address...Gold mining is now widely acknowledged as one of the significant sources of soil pollution in developed countries. In developing countries, the sources and levels of soil contamination have not been thoroughly addressed. Thus, this study was intended to determine the source of soil pollution and the level of contamination in the active and closed gold mining areas. The research paper presents the pollution load of heavy metals (lead-Pb, chromium-Cr, cadmium-Cd, copper-Cu, arsenic-As, manganese-Mn, and nickel-Ni) in 90 soil samples collected from the studied sites. Multivariate statistical analysis, including Principal Component Analysis (PCA) and Cluster Analysis (CA), coupled with correlation coefficient analysis, was performed to determine the possible sources of pollution in the study areas. The results indicated that Pb, Cr, Cu and Mn come from different sources than Cd, As and Ni. The results obtained from the metal pollution assessment using the Pollution Index (PI) and the Geoaccumulation Index (Igeo) confirmed that soils in the mining areas were contaminated in the range from moderately through strongly to highly contaminated soils. This study verified that soil contamination in the gold mining areas results from natural and anthropogenic processes. The current study findings would enhance our knowledge regarding the soil contamination level in the mining areas and the source of contamination. It is recommended to use PCA, CA, PI and Igeo to assess and monitor the heavy metal contaminated soil in gold mining areas.展开更多
The occurrence and accumulation of total mercury (T-Hg) in sediments collected from the Yarlung Zangbo River (YLZB),the Lhasa River,the Niyang River and the Palongzangbu River were analyzed and the soil samples simult...The occurrence and accumulation of total mercury (T-Hg) in sediments collected from the Yarlung Zangbo River (YLZB),the Lhasa River,the Niyang River and the Palongzangbu River were analyzed and the soil samples simultaneously collected from the bank were employed as control.Meanwhile,pollution status and potential ecological risk of Hg were calculated and assessed using index of geoaccumulation ( I geo ) and potential ecological risk assessment method (Er) in this study.The results showed that the T-Hg concentrations in sediments at eight sections of YLZB ranged from 4.23 to 48.1 μg/kg with mean concentration of 25.1 μg/kg,which was higher than background Hg value of soils in Tibet.T-Hg concentrations in sediments at three typical segments of YLZB were all significantly higher than those in soils collected from its bank (P<0.05).The Igeo and E r indexes revealed that the T-Hg pollution levels were slight pollution in two sections and moderate ecological risk in six sections of YLZB.Hg pollution risks also existed in the sediments of partial sections of the Lhasa River and the Niyang River,and slightly moderate Hg contamination with high ecological risk was presented in Lhasa urban district.The level of Hg in sediments of YLZB showed a notable spatial distribution characteristic with a trend of increasing firstly and then declining.Human activities played an important role in increasing Hg content in sediments of the river.展开更多
The distribution and accumulation of heavy metals in the surface sediment of Lake Junin National Reserve was evaluated using the pollution factor (CF), pollution load index (PLI) and geoaccumulation index (Igeo), duri...The distribution and accumulation of heavy metals in the surface sediment of Lake Junin National Reserve was evaluated using the pollution factor (CF), pollution load index (PLI) and geoaccumulation index (Igeo), during 2018. Surface sediment samples were collected from 10 sampling sites, with three repetitions, during the rainy and dry seasons. The heavy metals determined were Fe, Cu, Cr, Cd, Pb and Zn;As, was also determined. The results revealed the descending order of Fe > Cu > Zn > As > Pb > Cd > Cr concentrations recorded in the three sampling sectors. The values of the CF obtained for the metals qualified as low CF, in times of rain and low water. The CF values of Cd were qualified as moderate contamination factors at all sampling sites, except at LJ1 where it qualified as CF considerable. The PLI for Lake Junin ranged from 0.0721 to 0.3260. The Igeo obtained indicated that the sampling sites are not contaminated by the heavy metals under study. Therefore, the mean values for heavy metals and As did not exceed the reference values and sediment quality guidelines. In general terms, CF, PLI and Igeo indicate that there is no appreciable contamination by these metals in Lake Junin;except for Cd.展开更多
The pollution characteristics of Cd,Cr,Cu,Zn,Ni and Hg in agricultural soil around coal mining area were studied. After longterm mining activity,the soil around mining area was polluted by 6 elements to different degr...The pollution characteristics of Cd,Cr,Cu,Zn,Ni and Hg in agricultural soil around coal mining area were studied. After longterm mining activity,the soil around mining area was polluted by 6 elements to different degrees. Especially for Cd,its concentration was 3. 2times that of the National Soil Environmental Quality Standard Ⅱ. The values suggest that the contamination degree from strong to weak in soil is in the order of Hg > Cu > Cr > Zn > Ni > Cd. BCR sequential extraction results show that the order of average percentage about weak acid soluble fraction( F1) is that Cd > Ni > Zn > Cu > Hg > Cr,the order of 6 heavy metals available fraction( F1 + F2 + F3) is that Cu( 56. 89) > Cd( 50. 95) > Ni( 41. 52) > Zn( 35. 06) > Hg( 23. 04) > Cr( 4. 88). The RAC results indicate that soils were in a moderate potential ecological risk by pollution of Cd,and at the same time,Cu,Zn,Ni,Hg should be noted.展开更多
基金supported by the National Natural Science Foundation of China(No.40673061)the Research Program of Science and Technology of Quanzhou City Government(No.2007Z43)the Foundation of Key Laboratory of Nuclear Resources and Environment(East China Institute of Technology),Ministry of Education(No.070714).
文摘The concentrations of eight heavy metals （Cu, Zn, Pb, Cd, Cr, Ni, Hg, and As） in the intertidal surface sediments from Quanzhou Bay were determined to evaluate their levels and spatial distribution due to urbanization and economic development of Quanzhou region, southeast China. The ranges of the measured concentrations in the sediments are as follows： 24.8-119.7 mg/kg for Cu, 105.5-241.9 mg/kg for Zn, 34.3-100. 9 mg/kg for Pb, 0.28-0. 89 mg/kg for Cd, 51.1-121.7 mg/kg for Cr, 16.1-45.7 mg/kg for Ni, 0.17-0.74 mg/kg for Hg, and 17.7-30.2 mg/kg for As. The overall average concentrations of above metals exceed the primary standard criteria but meet the secondary standard criteria of the Chinese National Standard of Marine Sediment Quality. Several contents of Cu and Hg exceed the secondary standard criteria at some stations. The results of geoaccumulation index （Igeo） show that Cd causes strong pollution in most of the study area. There are no significant correlations among most of these heavy metals, indicating they have different anthropogenic and natural sources. Some locations present severe pollution by heavy metals depending on the sources, of which sewage outlets, aquatic breeding, and commercial ports are the main sources of contaminants to the area.
文摘Source apportionment studies of TSP （atmospheric particulate matter with aerodynamic diameters ≤ 100 μm） and PM10 （atmospheric particulate matter with aerodynamic diameters ≤ 10 μm） have revealed that soil dust is an important source of these particulates in China. In this study, the contamination of soil dust was assessed through the use of a geoaccumulation index （Igeo）. The mass concentration profiles of 17 elements （Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Br, Ba, and Pb） were established for urban soil dusts. Geochemical compositions of soils from 15 cities were used to represent background urban soil compositions. The results of this study indicated that a number of cities are severely polluted by particulates containing Ca, Cr, Ni, and Cu in both size fractions （TSP and PM10）. Contamination with Zn, Pb, Co, and Br was moderate to severe （Igeo 〉 2）. The Al and Fe concentrations were not high enough for them to be considered contaminants.
基金supported by the National Basic Research Program (973 Program) of China (Nos.2008CB418005 and 2004CB720200)the National Natural Science Foundation of China (No.40273004)
文摘This study focused on the concentration change of heavy metals of sediment cores in heavily polluted north area and less polluted middle area of Fuxian Lake in Southwest China.On the basis of the analysis of Cu,Ni,Ti,V,Pb,Cd,and Zn concentration-depth profiles,the pollution history of heavy metals was studied using 137cesium(137Cs) dating.The sources of heavy metals were distinguished by normalization of their profiles to aluminum and analysis of heavy metal concentrations of potential source materials.Geoaccumulation index(Igeo) was used to quantify their contamination intensity.The results showed that all the heavy metals found in the Fuxian Lake sediments originated naturally before 1980s.Cu,Ni,Ti,and V were still mainly natural in the north lake after 1980s,Cu,Ni,Ti,V,and Pb were mainly natural in the middle lake at all time,but the concentrations of Pb and Zn in the north lake were influenced by industrial wastes from the phosphorus fertilizer factory and cement plants.In all the lake,the contaminations of Cd and Zn were the results of agricultural cultivation using a large amount of fertilizers and the atmospheric fallouts of dusts from cement plants.At present,the geoaccumulation indices showed that the Fuxian Lake sediments were moderately to strongly polluted by Cd in the middle lake,and unpolluted to moderately polluted by Pb and Zn and strongly polluted by Cd in the north lake.Moreover,the pollution intensities of Cd,Zn,and Pb have been increased since 1980s.
基金Project(2012FJ1010)supported by the National Science and Technology Major Project,ChinaProject(2012BAC09B04)supported by the National"Twelfth Five-Year"Plan for Science&Technology,ChinaProject(2012AA06202)supported by the National High-tech Research and Development Program of China
文摘The pollution characteristics of Pb, Cd, Zn, Cu and Ni in soil of lead-zinc mining area were studied. The results indicate that the contamination degree followed the sequence of Cd〉Pb〉Zn〉Ni〉Cu and concentrations of Pb, Cd and Zn exceeded corresponding limits of the Chinese National Soil Environmental Quality Standard III. The soil was extremely polluted by Cd（Iego=5.26）, moderately to heavily polluted by Zn（Iego=2.38）, heavily to extremely polluted by Pb（Iego=4.13）. The results of BCR three-step sequential extraction procedure show that the active Cd, Pb and Zn were relatively high and might exert adverse effects on the plants grown in the soil, while Cu and Ni existed in soil with a relatively stable form. Potential ecological risk results indicate that soils were engaging in a high potential ecological risk by pollution of Cd and should be given rise to concern.
基金financially supported by the Independent Open Projects of Key Laboratory for Palygorskite Science and Applied Technology of Jiangsu Province,Huaiyin Institute of Technology,China(No.HPK201705)the Independent Fund of Jiangsu Academy of Agricultural Sciences,China(No.6111637)。
文摘Soil contamination by heavy metals is a problem in agricultural irrigation systems.To assess the accumulation and sources of heavy metals in the Yongji irrigation district of the Hetao area,Inner Mongolia,China,195 soil samples from 39 sites(0–100 cm)were collected,and Zn,Cu,Pb,Cr,and Cd concentrations were analyzed.The mean concentrations were 107.17,32.48,12.31,53.53,and 0.22 mg kg-1,respectively,with no significant differences between soil depths(P>0.05).Concentrations of Zn,Cu,and Cd were higher than the background levels,with moderate accumulation;the contamination factor(CF)values were 1.9,1.7,and 1.9,respectively,and the geoaccumulation index(Igeo)was>0.Concentrations of Pb and Cr were lower than,or close to,the background levels(CF<1,Igeo<0),indicating that they originated from a natural source.The monomial potential ecological risk index(Eri)for Zn,Cu,Pb,and Cr was low;Eri for Cd was 55.73,implying a moderate risk.The grade of potential ecological risk index of the five heavy metals(RI)was low,declining from south to north.The studied soils were contaminated with Zn,Cu,and Cd;principal component(PC)analysis implicated the enrichment of Cd and partial Cu(high loading in PC 2)was related to agricultural activities;Zn and partial Cu,closely associated with PC 3,may have originated from irrigation water from the Yellow River.Future agricultural development should focus on fertilizer and pesticide application and the quality of irrigation water.
基金The National Key Technologies R＆D Program of China during the 12th Five-Year Plan Period, No.2010BAC09B07 National Natural Science Foundation of China, No.U0933604 The Reservoir＇s Train- ing Projects of Yunnan Mid-Youth Scientific Technical Leader, No.2009CI050
文摘The resource development and changes of hydrological regime, sediment and water quality in the Mekong River basin have attracted great attentions. This research aimed to enhance the study on transboundary pollution of heavy metals in this international river. In this study, eight sampling sites were selected to collect the bed sand samples along the mainstream of the Mekong River. In addition, the contents of 5 heavy metal elements and their spatial variability along the mainstream of the river were analyzed. The geoaccumulation index （l^eo） and potential ecological risk analysis were employed to assess heavy metal pol- lution status in the mainstream of the Mekong River. The results show that the average con- tent of the heavy metal elements Zn is 91.43 mg/kg, Pb is 41.85 mg/kg, and As is 21.84 mg/kg in the bed sands of the Upper Mekong River, which are higher than those （Zn 68.17 mg/kg, Pb 28.22 mg/kg, As 14.97 mg/kg） in the Lower Mekong. The average content of Cr in the Lower Mekong is 418.86 mg/kg, higher than that in the Upper Mekong （42.19 mg/kg）. Luang Prabang has a very high Cr concentration with 762.93 mg/kg and Pakse with 422.90 mg/kg. The concentration of Cu in all of the 8 sampling sites is similar, except for in Jiajiu with 11.70 mg/kg and Jiebei with 7.00 mg/kg. The results of the geoaccumulation index reveal that contaminations caused by Zn and Pb while Pb and As are more than those by Zn in Upper Mekong. Cr is the primary pollutant in the Lower Mekong, especially at Luang Prabang and Pakse. Slight pollution with As also occurs in Pakse. The potential ecological risk index indi- cates that the potential ecological risk of heavy metals in the mainstream of the Mekong River is low. We argue that the pollution of water quality and contamination of heavy metals in bed sediment caused by mining of mineral resources or geochemical background values in the Mekong is not transmitted from the Upper to the Lower Mekong because of the reservoir sedimentation and dilution along the river.
文摘Introduction:In this study,metal pollution and their sources in surface soils were evaluated by pollution indices and multivariate statistical techniques in association with a geographical information system(GIS).Methods:Surface soil samples were collected in dry season from different locations of Dhaka Aricha highway and analyzed by energy dispersive X-ray fluorescence(EDXRF).Results:Thirteen different metals were found in the tested samples.Pollution indices are determined by enrichment factor in an order of Zr>Sn>P>Mn>Zn>Rb>Fe>Ba>Sr>Ti>K>Ca>Al.The resulting geoaccumulation index(Igeo)value shows the following order:Sn>Zr>P>Mn>Zn>Rb>Fe>Ba>Ti>Sr>K>Ca>Al.Contamination factors(CFs)of the metals range from 1.422 to 3.979(Fe);0.213 to 1.089(Al);0.489 to 3.484(Ca);1.496 to 2.372(K);1.287 to 3.870(Ti);2.200 to 14.588(Mn);5.938 to 56.750(Zr);0.980 to 3.500(Sr);2.321 to 4.857(Rb);2.737 to 6.526(Zn);16.667 to 27.333(Sn);3.157 to 16.286(P);and 0.741 to 3.328(Ba).Pollution load index calculated from the CFs indicates that soils are strongly contaminated by Zr and Sn.Principal component analysis(PCA)of parameters exhibits three major components.R-mode cluster analysis reveals three distinct groups in both site and metal basis clustering that shows a similar pattern with the PCA.Conclusions:These results might be helpful for future monitoring of further increase of heavy metal concentrations in surface soils along highways.
文摘Daba Mountain area is one of the two endemic selenosis areas in China,which may relate with the environmental behaviors of selenium (Se) in soil.This study focuses on the concentraion and distribution of Se and its relationships with some other elements in natural soil in the area.The average concentration of Se in Daba Mountain soils was 14.3 times higher than the value cited for natural soil background worldwide,suggesting that soils in the region were contaminated by the element.The finding was confirmed...
文摘A total of 52 soil samples of Hohhot City were collected and four heavy metals and eight organochlorine pesticides were analyzed. The results showed that Cr, Cu, Zn, and Pb in soil were in range of 20.54 - 48.15 mg/kg, 40.10 - 94.60 mg/kg, 35.14 - 110.48 mg/kg, 38.86g - 245.36 mg/kg, with a mean value of 37.24 mg/kg, 60.76 mg/kg, 80.49 mg/kg, and 145.99 mg/kg, respectively. The high degree of variation of Pb, Zn, and Cu, reflected that the heavy metals were mainly interfered by human factors. The content values of ∑DDTs ranged from 5.01 ng/g to 105.08 ng/g with a mean of 36.94 ng/g, while the ∑HCHs ranged from 6.52 ng/g to 48.65 ng/g with an average of 23.29 ng/g, indicated that DDTs were highly used than HCHs in the study area. The relatively low α-HCH/γ-HCH ratio and relatively high o,p’-DDT/p,p’-DDT ratio indicated the application of lindane and dicofol on regional agricultural soil. The mean Igeo values was Pb (2.9) > Cu (1.5) > Cr (-0.31) > Zn (-0.35), revealing that the soil in Hohhot City was not polluted by Cr and Zn (Igeo 0), moderate polluted by Cu (1 Igeo 2), moderate to heavy pollution by Pb (2 Igeo 3). The range of potential ecological risk index of metals was from 35.02 to 132.96, indicating low to moderate potential ecological risk. HCHs in all soil samples were less than 50 ng/g, which could be considered as unpolluted, while DDTs in several samples were between 50 and 500 ng/g, which could be regarded as having low pollution.
文摘Soil characterization and heavy metals in different layers (0 - 15 cm;15 - 30 cm and 30 - 45 cm depth) of automobile mechanic waste dumps were studied. The soils showed remarkably high levels of all the metals above background concentrations with most (Ni, Cu, Fe, Cr and Cd) decreasing with soil depth. The distribution pattern were in the following order Fe > Cu > Zn > Pb > Cr > Ni > Cd. Across all the sampling locations and profiles, Fe and Cd showed the highest (476.4 μg·g-1) and least (37.5 μg·g-1) mean concentrations respectively. Pollution load index (PLI) and index of geoaccumulation (Igeo) revealed overall high and moderate contamination respectively but the enrichment factors (EFs) for Pb Ni and Cd are severe. The inter-element relationship revealed the identical source of elements in the soils of the studied area. The accuracy of the results has been cheeked using the standard reference material;SRM (PACS-2). The mechanic waste dumps represent potential sources of heavy metal pollution to environment. The elevated levels of heavy metals in these soil profiles constitute a serious threat to both surface and groundwater.
文摘In order to investigate distributions of heavy metal pollution in Quanzhou Bay wetland, the total concentration and chemical partitioning of a number of heavy metals （Cu, Zn, Cd, Pb, Cr, Hg） in sediments of three sampling sites of Quanzhou Bay wetland and their availability to Suaeda australis were analyzed. The Geoaccumulation Index （Igeo） values reveal that the sediments of three sampling sites may all be considered as moderately contaminated for Pb and Zn, and all sediments might be strongly contaminated with cadmium. The partitioning analyses revealed the measured heavy metals in three sites are bound to the exchangeable fraction at lower concentrations. The measured metals in a considerable amount are bound to the reducible and oxidizable fractions, and a high proportion of the measured heavy metals were distributed in the residual fraction in the sediment samples. The concentrations of Cd in each chemical phase extracted from the sediments are above natural global background levels and should be further investigated because of its toxicity. Suaeda australis has different accumulation abilities for the measured heavy metals. For the root and stem, the bioaccumulation ability assessed by bioaccumulation factor （BAF） for the measured heavy metals follows the decreasing order as： Cu〉Cr〉 Zn〉Cd, Pb, Hg. In the leaf, stronger bioaccumulation ability for Hg is exhibited. The heavy metal concentrations in Suaeda australis roots have positive correlations with their available fractions, while the exchangeable fraction of Cu and Cd might have be more important to both mature plant roots and seedling roots uptake than other fractions; as for Cr, the oxidizable fraction might make a greater contribution to the plant root uptake; as for Zn, the reducible fraction might make so contribution ; and for Pb, the oxidizable fraction might make a significant contribution to the mature plant root uptake, however, the exchangeable fraction might have a significant contribution to the seedling root uptake.
文摘In Tunisia,water scarcity is only adding pressure on water demand in agriculture.In the context of sustainable development goals,Tunisia has been reusing treated wastewater(TWW)as a renewable and inexpensive source for soil fertigation and groundwater(GW)recharge.However,major risks can be expected when the irrigation water is of poor quality.This study aims for evaluating the potential risk of TWW and GW irrigation on soil parameters.Accordingly,we evaluated the suitability of water quality through the analysis of major and minor cations and anions,metallic trace elements(MTEs),and the sodium hazard by using the sodium adsorption ratio(SAR)and the soluble sodium percentage(SSP).The risk of soil sodicity was further assessed by SAR and the exchangeable sodium percentage(ESP).The degree of soil pollution caused by MTEs accumulation was evaluated using geoaccumulation index(Igeo)and pollution load index(PLI).Soil maps were generated using inverse spline interpolation in ArcGIS software.The results show that both water samples(i.e.,TWW and GW)are suitable for soil irrigation in terms of salinity(electrical conductivity<7000μS/cm)and sodicity(SAR<10.00;SSP<60.00%).However,the contents of PO_(4)^(3-),Cu^(2+),and Cd^(2+)exceed the maximum threshold values set by the national and other standards.Concerning the soil samples,the average levels of SAR and ESP are within the standards(SAR<13.00;ESP<15.00%).On the other hand,PLI results reveal moderate pollution in the plot irrigated with TWW and no to moderate pollution in the plot irrigated with GW.Igeo results indicate that Cu^(2+)is the metallic trace element(MTE)with the highest risk of soil pollution in both plots(Igeo>5.00),followed by Ni^(2+)and Pb^(2+).Nevertheless,Cd^(2+)presents the lowest risk of soil pollution(Igeo<0.00).Statistical data indicates that Ca^(2+),Na+,Ni^(2+),and Pb^(2+)are highly distributed in both plots(coefficient of variation>50.0%).This study shows that the use of imagery tools,such as ArcGIS,can provide important information for evaluating t
文摘Surface sedimental samples were collected from(1)Le An River in Jiangxi Province, south of China,and(2)several lakes located in southwest of Germany.Concentrations of heavy metals in these samples were determined.Moreover,the situations of heavy metal pollution in two regions were comprehensively assessed by combined index of geoaccumulation with visualized multi- variate graphical method——modified Chernoff Face Graph.Face graphs intuitively demonstrated strong heavy metal contamination in Le An River,especially copper pollution.However,in lakes' sedimental samples,contamination of other heavy metals showed mild or clean except cadmium and chromium.
文摘Gold mining is now widely acknowledged as one of the significant sources of soil pollution in developed countries. In developing countries, the sources and levels of soil contamination have not been thoroughly addressed. Thus, this study was intended to determine the source of soil pollution and the level of contamination in the active and closed gold mining areas. The research paper presents the pollution load of heavy metals (lead-Pb, chromium-Cr, cadmium-Cd, copper-Cu, arsenic-As, manganese-Mn, and nickel-Ni) in 90 soil samples collected from the studied sites. Multivariate statistical analysis, including Principal Component Analysis (PCA) and Cluster Analysis (CA), coupled with correlation coefficient analysis, was performed to determine the possible sources of pollution in the study areas. The results indicated that Pb, Cr, Cu and Mn come from different sources than Cd, As and Ni. The results obtained from the metal pollution assessment using the Pollution Index (PI) and the Geoaccumulation Index (Igeo) confirmed that soils in the mining areas were contaminated in the range from moderately through strongly to highly contaminated soils. This study verified that soil contamination in the gold mining areas results from natural and anthropogenic processes. The current study findings would enhance our knowledge regarding the soil contamination level in the mining areas and the source of contamination. It is recommended to use PCA, CA, PI and Igeo to assess and monitor the heavy metal contaminated soil in gold mining areas.
基金Supported by Investigation on Fishery Resources and Environment in Key Waters of TibetSpecial Scientific Research Projects of Public Welfare Industry(Agriculture)(201503108)
文摘The occurrence and accumulation of total mercury (T-Hg) in sediments collected from the Yarlung Zangbo River (YLZB),the Lhasa River,the Niyang River and the Palongzangbu River were analyzed and the soil samples simultaneously collected from the bank were employed as control.Meanwhile,pollution status and potential ecological risk of Hg were calculated and assessed using index of geoaccumulation ( I geo ) and potential ecological risk assessment method (Er) in this study.The results showed that the T-Hg concentrations in sediments at eight sections of YLZB ranged from 4.23 to 48.1 μg/kg with mean concentration of 25.1 μg/kg,which was higher than background Hg value of soils in Tibet.T-Hg concentrations in sediments at three typical segments of YLZB were all significantly higher than those in soils collected from its bank (P<0.05).The Igeo and E r indexes revealed that the T-Hg pollution levels were slight pollution in two sections and moderate ecological risk in six sections of YLZB.Hg pollution risks also existed in the sediments of partial sections of the Lhasa River and the Niyang River,and slightly moderate Hg contamination with high ecological risk was presented in Lhasa urban district.The level of Hg in sediments of YLZB showed a notable spatial distribution characteristic with a trend of increasing firstly and then declining.Human activities played an important role in increasing Hg content in sediments of the river.
文摘The distribution and accumulation of heavy metals in the surface sediment of Lake Junin National Reserve was evaluated using the pollution factor (CF), pollution load index (PLI) and geoaccumulation index (Igeo), during 2018. Surface sediment samples were collected from 10 sampling sites, with three repetitions, during the rainy and dry seasons. The heavy metals determined were Fe, Cu, Cr, Cd, Pb and Zn;As, was also determined. The results revealed the descending order of Fe > Cu > Zn > As > Pb > Cd > Cr concentrations recorded in the three sampling sectors. The values of the CF obtained for the metals qualified as low CF, in times of rain and low water. The CF values of Cd were qualified as moderate contamination factors at all sampling sites, except at LJ1 where it qualified as CF considerable. The PLI for Lake Junin ranged from 0.0721 to 0.3260. The Igeo obtained indicated that the sampling sites are not contaminated by the heavy metals under study. Therefore, the mean values for heavy metals and As did not exceed the reference values and sediment quality guidelines. In general terms, CF, PLI and Igeo indicate that there is no appreciable contamination by these metals in Lake Junin;except for Cd.
基金Supported by Project for Social Development of Guizhou Province(SY20103013)
文摘The pollution characteristics of Cd,Cr,Cu,Zn,Ni and Hg in agricultural soil around coal mining area were studied. After longterm mining activity,the soil around mining area was polluted by 6 elements to different degrees. Especially for Cd,its concentration was 3. 2times that of the National Soil Environmental Quality Standard Ⅱ. The values suggest that the contamination degree from strong to weak in soil is in the order of Hg > Cu > Cr > Zn > Ni > Cd. BCR sequential extraction results show that the order of average percentage about weak acid soluble fraction( F1) is that Cd > Ni > Zn > Cu > Hg > Cr,the order of 6 heavy metals available fraction( F1 + F2 + F3) is that Cu( 56. 89) > Cd( 50. 95) > Ni( 41. 52) > Zn( 35. 06) > Hg( 23. 04) > Cr( 4. 88). The RAC results indicate that soils were in a moderate potential ecological risk by pollution of Cd,and at the same time,Cu,Zn,Ni,Hg should be noted.
