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1.
Dedication 总被引:1,自引:0,他引:1
Elevated concentrations of arsenic (As) occurred during warm months in water from the outlet of Lake Mohawk in northwestern
New Jersey. The shallow manmade lake is surrounded by residential development and used for recreation. Eutrophic conditions
are addressed by alum and copper sulfate applications and aerators operating in the summer. In September 2005, arsenite was
dominant in hypoxic to anoxic bottom water. Filterable As concentrations were about 1.6–2 times higher than those in the upper
water column (23–25 μg/L, mostly arsenate). Hypoxic/anoxic and near-neutral bottom conditions formed during the summer, but
became more oxic and alkaline as winter approached. Acid-leachable As concentrations in lake-bed sediments ranged up to 694 mg/kg
in highly organic material from the tops of sediment cores but were <15 mg/kg in geologic substrate. During warm months, reduced
As from the sediment diffuses into the water column and is oxidized; mixing by aerators, wind, and boat traffic spreads arsenate
and metals, some in particulate form, throughout the water column. Similar levels of As in sediments of lakes treated with
arsenic pesticides indicate that most of the As in Lake Mohawk probably derives from past use of arsenical pesticides, although
records of applications are lacking. The annual loss of As at the lake outlet is only about 0.01% of the As calculated to
be in the sediments, indicating that elevated levels of As in the lake will persist for decades. 相似文献
2.
Reis AP Patinha C Ferreira da Silva E Sousa AJ 《Environmental geochemistry and health》2012,34(2):229-241
The Marrancos gold mineralisation has a chemical assemblage of Fe–As–Se–Bi–Au–Ag–Te–(Cu–Pb–Zn–Sn–W). The −200 mesh of 144
topsoil samples was analysed by ICP–MS to determine total contents of 53 elements that include potentially harmful elements
like Cd, As and Pb. The soil geochemistry shows that some trace elements occur in considerably high concentrations. On the
basis of data for total metal concentrations, 10 topsoil samples were selected to carry out a metal fractionation study using
a selective extraction method. A set of four leaches of increasing strength was used sequentially in the soil samples. Across
the study area, there is some evidence of past mining and exploration activity, indicating that these soils may be locally
disturbed. The shallow mineralised quartz veins were exploited for gold by the Romans. Several galleries were constructed
during the 2nd World War, probably for the exploration of quartz–cassiterite–wolframite veins. However, the main mineralised
body in depth was never explored. The results of metal fractionation show different partitions for the three elements. Total
Cd concentrations in these soils are low, with a median value of 0.1 mg/kg. In average, 12% of total Cd is adsorbed by clays
and/or co-precipitated with carbonates, and 19% is bounded to Fe–Mn oxyhydroxides. However, the low concentrations indicate
that the metal does not represent an immediate risk to human health. For Pb, metal fractionation shows that, on average, 22%
of Pb is adsorbed by amorphous Fe and Mn oxides, but the samples from the northern part of the area have the major fractions
of Pb in soluble forms. The low probability of exposure in this part of the study area decreases the risk posed by this heavy
metal. Total As concentrations in the Marrancos soils are extremely high. A large area has As concentrations above 1,000 mg/kg.
For As, metal fractions in the sulphide phase vary between 84 and 98% in the studied samples. But one sample has 20% of total
As in easily reducible forms, corresponding to a partial concentration of 1,800 mg/kg that has a high probability of being
bioavailable. The most labile As forms occur at the southern part of the area, where the probability of exposure is higher
and the risk of human health increases in the same order. From the three studied potentially harmful elements, As is certainly
the element of concern. 相似文献
3.
Anawar HM Akai J Yoshioka T Konohira E Lee JY Fukuhara H Tari Kul Alam M Garcia-Sanchez A 《Environmental geochemistry and health》2006,28(6):553-565
The extensive extraction of arsenic (As)-contaminated groundwaters for drinking, household and agricultural purposes represents
a serious health concern in many districts of Bangladesh. This laboratory-based incubation study investigated the sources
and mechanisms of As mobilization in these groundwaters. Several incubation studies were carried out using sediments collected
from the Bangladesh aquifer that were supplemented, or not, with different nutrients, followed by an analysis of the sediment
suspensions for pH, ORP (oxidation-reduction potential), EC (electrical conductivity) and As and Fe(ΙΙ) concentrations. In
the substrate-amended sediment suspensions incubated under anaerobic environment, there was a mobilization of As (maximum:
50–67 μg/l) and Fe(ΙΙ) (maximum: 182 μg/l), while the ORP value decreased immediately and drastically (as much as −468 mV
to −560 mV) within 5–6 days. In the sediment suspensions incubated under control and aerobic conditions, no significant As
mobilization occurred. The simultaneous mobilization of As and Fe(ΙΙ) from sediments is a strong indication that their mobilization
resulted from the reduction of Fe oxyhydroxide by the enhanced activity of indigenous bacteria present in the sediments; this
phenomenon also provides insights on the mobilization mechanism of As in groundwater. The concentrations of As in the sediments
used in the incubation studies were strongly linked to the gradients of redox potential development that was stimulated by
the quantity of organic nutrient (glucose) used. The penetration of surface-derived organic matter into the shallow aquifer
may stimulate the activity of microbial communities, thereby leading to a reduction of iron oxyhydroxide and As release. 相似文献
4.
A. H. M. Selim Reza Jiin-Shuh Jean Huai-Jen Yang Ming-Kuo Lee Hua-Fen Hsu Chia-Chuan Liu Yao-Chang Lee Jochen Bundschuh Kao-Hong Lin Chi-Yu Lee 《Environmental geochemistry and health》2011,33(3):235-258
Humic substances in groundwater and aquifer sediments from the arsenicosis and Blackfoot disease (BFD) affected areas in Bangladesh
(Bengal delta plain) and Taiwan (Lanyang plain and Chianan plain) were characterized using fluorescence spectrophotometry
and Fourier transform infrared (FT-IR) spectroscopy. The results demonstrate that the mean concentration of As and relative
intensity of fluorescent humic substances are higher in the Chianan plain groundwater than those in the Lanyang plain and
Bengal delta plain groundwater. The mean As concentrations in Bengal delta plain, Chianan plain, and Lanyang plain are 50.65 μg/l
(2.8–170.8 μg/l, n = 20), 393 μg/l (9–704 μg/l, n = 5), and 104.5 μg/l (2.51–543 μg/l, n = 6), respectively. Average concentrations and relative fluorescent intensity of humic substances in groundwater are 25.381 QSU
(quinine standard unit) and 17.78 in the Bengal delta plain, 184.032 QSU and 128.41 in the Chianan plain, and 77.56 QSU and
53.43 in the Lanyang plain. Moreover, FT-IR analysis shows that the humic substances extracted from the Chianan plain groundwater
contain phenolic, alkanes, aromatic ring and amine groups, which tend to form metal carbon bonds with As and other trace elements.
By contrast, the spectra show that humic substances are largely absent from sediments and groundwater in the Bengal delta
plain and Lanyang plain. The data suggest that the reductive dissolution of As-adsorbed Mn oxyhydroxides is the most probable
mechanism for mobilization of As in the Bengal delta plain. However, in the Chianan plain and Lanyang plain, microbially mediated
reductive dissolution of As-adsorbed amorphous/crystalline Fe oxyhydroxides in organic-rich sediments is the primary mechanism
for releasing As to groundwater. High levels of As and humic substances possibly play a critical role in causing the unique
BFD in the Chianan plain of SW Taiwan. 相似文献
5.
Mohammad Mahmudur Rahman Gary Owens Ravi Naidu 《Environmental geochemistry and health》2009,31(Z1):179-187
Chronic exposure to arsenic (As) causes significant human health effects, including various cancers and skin disorders. Naturally
elevated concentrations of As have been detected in the groundwater of Bangladesh. Dietary intake and drinking water are the
major routes of As exposure for humans. The objectives of this study were to measure As concentrations in rice grain collected
from households in As-affected villages of Bangladesh where groundwater is used for agricultural irrigation and to estimate
the daily intake of As consumed by the villagers from rice. The median and mean total As contents in 214 rice grain samples
were 131 and 143 μg/kg, respectively, with a range of 2–557 μg/kg (dry weight, dw). Arsenic concentrations in control rice
samples imported from Pakistan and India and on sale in Australian supermarkets were significantly lower (p < 0.001) than in rice from contaminated areas. Daily dietary intake of As from rice was 56.4 μg for adults (males and females)
while the total daily intake of As from rice and from drinking water was 888.4 and 706.4 μg for adult males and adult females,
respectively. From our study, it appears that the villagers are consuming a significant amount of As from rice and drinking
water. The results suggest that the communities in the villages studied are potentially at risk of suffering from arsenic-related
diseases. 相似文献
6.
The Salí River Basin in north-west Argentina (7,000 km2) is composed of a sequence of Tertiary and Quaternary loess deposits, which have been substantially reworked by fluvial and
aeolian processes. As with other areas of the Chaco-Pampean Plain, groundwater in the basin suffers a range of chemical quality
problems, including arsenic (concentrations in the range of 12.2–1,660 μg L−1), fluoride (50–8,740 μg L−1), boron (34.0–9,550 μg L−1), vanadium (30.7–300 μg L−1) and uranium (0.03–125 μg L−1). Shallow groundwater (depths up to 15 m) has particularly high concentrations of these elements. Exceedances above WHO (2011) guideline values are 100% for As, 35% for B, 21% for U and 17% for F. Concentrations in deep (>200 m) and artesian groundwater
in the basin are also often high, though less extreme than at shallow depths. The waters are oxidizing, with often high bicarbonate
concentrations (50.0–1,260 mg L−1) and pH (6.28–9.24). The ultimate sources of these trace elements are the volcanic components of the loess deposits, although
sorption reactions involving secondary Al and Fe oxides also regulate the distribution and mobility of trace elements in the
aquifers. In addition, concentrations of chromium lie in range of 79.4–232 μg L−1 in shallow groundwater, 129–250 μg L−1 in deep groundwater and 110–218 μg L−1 in artesian groundwater. All exceed the WHO guideline value of 50 μg L−1. Their origin is likely to be predominantly geogenic, present as chromate in the ambient oxic and alkaline aquifer conditions. 相似文献
7.
为弄清大同盆地地下水中影响砷的迁移、富集的主要地球化学与生物地球化学过程,为区域供水安全提供指导作用,针对高砷地下水系统开展了水文地球化学与含水层沉积物全岩地球化学研究;并在此基础上探讨了研究区高砷地下水成因。结果表明,研究区高砷地下水为偏碱性、强还原环境,砷含量为0.31~452μg·L-1,主要以砷酸盐形式存在,地下水中砷与三价铁的浓度有显著的相关性。高砷含水层沉积物中有机质、铁与砷含量表现出显著相关性。以上结果说明,碱性还原环境有利于地下水中砷的富集;微生物参与下,沉积物相有机质的氧化和Fe氧化物/氢氧化物的还原过程是本区高砷地下水形成的主控因素。 相似文献
8.
Water-dissolved oxygen was supplied into anaerobic aquifer , which oxidized Fe(II), Mn(II) and trivalent arsenic and changed
them into undissolved solid matter through hydrolysis, precipitation, co-precipitation and adsorption processes. The experiment
was carried out on the column imitated a bore core of anaerobic aquifer with water phase containing Fe(II), Mn(II), As(III)
concentration of 45.12 mg/L, 14.52 mg/L, 219.4 μg/L, respectively and other ions similarly composition in groundwater. After
6 days of air supply, concentration of iron reduced to 0.38 mg/L, manganese to 0.4 mg/L, arsenic to 9.8 μg/L (equivalent 99.16%
of iron, 97.25% of manganese and 95.53% of arsenic fixed), and for other ions, the concentration changed almost according
to general principles. Ion phosphate and silicate strongly influenced on arsenic removal but supported iron and manganese
precipitation from water phase. Based on the experimental results, new model of groundwater exploitation was proposed. 相似文献
9.
Ameliorants to immobilize Cd in rice paddy soils contaminated by abandoned metal mines in Korea 总被引:1,自引:0,他引:1
Yong Sik Ok Sung-Chul Kim Dong-Kuk Kim Jeffrey G. Skousen Jin-Soo Lee Young-Wook Cheong Su-Jung Kim Jae E. Yang 《Environmental geochemistry and health》2011,33(1):23-32
The Yarlung Tsangbo (YT) is a large river running across southern Tibet and has significant effects on its lower reaches,
the Ganges–Brahmaputra Basin. In order to investigate the geochemical features of the YT, 18 surface sediment samples were
collected; ten trace element concentrations were measured for bulk sediments and two fine grain size fractions. Meanwhile,
basic physicochemical parameters and element concentrations of river water were also analyzed. Results indicated that the
river water was alkaline (pH 8.42) and that dissolved oxygen was mainly controlled by river water temperature. Some elements
(e.g., Zn and Ni) showed close negative relationship to mean grain size of the sediments. Concentrations of most heavy metals,
except As of the YT bulk sediments, were similar to those of Upper Crustal Concentration and its lower reaches, indicating
almost no anthropogenic impact. Arsenic of the YT sediments was derived fundamentally from the parent rocks of the YT Basin
and was far higher than that of its lower reaches. This indicates that relatively small amounts of As from the study area
were transported down to the Brahmaputra River under present, relatively dry climatic conditions. However, more YT sediments
might have been transported to its low reaches during the Holocene due to the wet climate, giving high As concentration in
Holocene sediments of the Ganges–Brahmaputra Basin. Thus, As transported by the YT may produce important influence on the
Ganges–Brahmaputra Basin and contribute to its high As concentration in groundwater. 相似文献
10.
Edu Inam Supawan Khantotong Kyoung-Woong Kim Bulgan Tumendemberel Sugar Erdenetsetseg Tamir Puntsag 《Environmental geochemistry and health》2011,33(1):57-69
The environmental impacts of Boroo gold mine project in Mongolia was evaluated by chemical characterization of trace element concentrations in water, soils and tailing dam sediment samples. The results showed that concentrations of B, Cd, Ni and Se in the water samples were within the accepted levels of the Mongolia water quality standard (MNS4586: 1998). However, the concentrations of Al, As, Cu, Mn, Fe, Pb, U and Zn were higher than the maximum allowable concentration especially in the monitoring and heap leach wells. The average concentrations of As, Cd, Cu, Ni, Pb and Zn in the tailing dam sediment were 4419, 58.5, 56.0, 4.8, 20.6 and 25.7 mg/kg, respectively. Generally, arsenic and heavy metals in the soil samples were within the acceptable concentrations of the soil standard of Mongolia (MNS 5850: 2008). The chemical characterization of As solid phase in tailing dam sediment showed that the majority of As were found in the residual fraction comprising about 74% of total As. Assessing the potential risk to humans, simple bioavailability extraction test was used to estimate bioavailability of arsenic and heavy metals, and the concentrations extracted from tailing dam sediment were; 288.2 mg/kg As, 7.2 mg/kg Cd, 41.1 mg/kg Cu, 13.5 mg/kg Pb, 4.7 mg/kg Ni and 23.5 mg/kg Zn, respectively. From these results, the Boroo gold mine project has presently not significantly impacted the environment, but there is a high probability that it may act as a source of future contamination. 相似文献
11.
Patel KS Shrivas K Brandt R Jakubowski N Corns W Hoffmann P 《Environmental geochemistry and health》2005,27(2):131-145
Arsenic contamination in the environment (i.e. surface, well and tube-well water, soil, sediment and rice samples) of central
India (i.e. Ambagarh Chauki, Chhattisgarh) is reported. The concentration of the total arsenic in the samples i.e. water (n=64), soil (n=30), sediment (n=27) and rice grain (n=10) were ranged from 15 to 825 μg L−1, 9 to 390 mg kg−1, 19 to 489 mg kg−1 and 0.018 to 0.446 mg kg−1, respectively. In all type of waters, the arsenic levels exceeded the permissible limit, 10 μg L−1. The most toxic and mobile inorganic species i.e. As(III) and As(V) are predominantly present in water of this region. The
soils have relatively higher contents of arsenic and other elements i.e. Mg, Al, Si, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu,
Zn, As, Ga, Zr, Sn, Sb, Pb and U. The mean arsenic contents in soil of this region are much higher than in arsenic soil of
West Bengal and Bangladesh. The lowest level of arsenic in the soil of this region is 3.7 mg kg−1 with median value of 9.5 mg kg−1. The arsenic contents in the sediments are at least 2-folds higher than in the soil. The sources of arsenic contamination
in the soil of this region are expected from the rock weathering as well as the atmospheric deposition. The environmental
samples i.e. water, soil dust, food, etc. are expected the major exposure for the arsenic contamination. The most of people
living in this region are suffering with arsenic borne diseases (i.e. melanosis, keratosis, skin cancer, etc.). 相似文献
12.
Heavy metal pollution caused by traffic activities is increasingly becoming a great threat to urban environmental quality
and human health. In this paper, soils of Kerman urban and suburban areas were collected to assess the potential effects of
traffic and other vehicle-related pollution by heavy metal accumulation in soils. Eighty-six samples were collected along
streets and from residential and rural sectors, as well as vehicle-related workshops from depth of 0–5 and 15–20 cm and analyzed
by flame atomic absorption spectrometry (FAAS) for heavy metals (Cd, Cr, Cu, Pb, Sn and Zn), as well as major elements (Al,
Ca, Fe and Mn). Several hot-spot areas were identified in the composite geochemical maps produced based on Geographical Information
System (GIS) technology. The majority of the hot-spot areas were identified to be vehicle-related workshops, fuel stations
and road junctions. The most polluted hot-spot in the study area was located in soils close to a car battery processing workshop
in the southwestern part of Kerman city, with concentrations of Cd (0.32 mg/kg), Cr (169 mg/kg), Cu (250 mg/kg), Pb (5,780 mg/kg),
Sn (27.2 mg/kg) and Zn (178 mg/kg) of 1, 8.5, 8.3, 230, 13.5 and 3 times more than the relevant mean concentrations in natural
soils, respectively. Traffic pollution has resulted in significant accumulation of heavy metals in soils and sediments, and
that level of accumulation varied remarkably among elements. Based on X-ray diffraction analysis, most parts of soils and
sediments of the Kerman basement consist of calcite and clay minerals. Abundance of clay minerals and medium to alkaline pH
causes low mobility of heavy metals in soils of Kerman. 相似文献
13.
Ravi Naidu Euan Smith S. M. Imamul Huq Gary Owens 《Environmental geochemistry and health》2009,31(Z1):61-68
The bioavailability of arsenic (As) in the soil environment is largely governed by its adsorption–desorption reactions with
soil constituents. We have investigated the sorption–desorption behaviour of As in four typical Bangladeshi soils subjected
to irrigation with As-contaminated groundwater. The total As content of soils (160 samples) from the Laksham district ranged
from <0.03 to approximately 43 mg kg−1. Despite the low total soil As content, the concentration of As in the pore water of soils freshly irrigated with As-contaminated
groundwater ranged from 0.01 to 0.1 mg l−1. However, when these soils were allowed to dry, the concentration of As released in the pore water decreased to undetectable
levels. Remoistening of soils to field moisture over a 10-day period resulted in a significant (up to 0.06 mg l−1) release of As in the pore water of soils containing >10 mg As kg−1 soil, indicating the potential availability of As. In soils containing <5 mg As kg−1, As was not detected in the pore water. A comparison of Bangladeshi soils with strongly weathered long-term As-contaminated
soils from Queensland, Australia showed a much greater release of As in water extracts from the Australian soils. However,
this was attributed to the much higher loading of As in these Australian soils. The correlation of pore water As with other
inorganic ions (P, S) showed a strongly significant (P < 0.001) relationship with P, although there was no significant relationship between As and other inorganic cations, such
as Fe and Mn. Batch sorption studies showed an appreciable capacity for both AsV and AsIII sorption, with AsV being retained in much greater concentrations than AsIII. 相似文献
14.
In this study, the content and speciation of arsenic in coal waste and gas condensates from coal waste fires were investigated,
respectively, using the digestion and sequential extraction methods. The fresh and fired-coal waste samples were collected
from Yangquan, which is one of the major coal production regions in northern China. High-performance liquid chromatography-inductively
coupled plasma-mass spectrometry (HPLC-ICP-MS) was used to determine the concentrations of four major arsenic species [As(III),
As(V), monomethylarsonic acid (MMA) and dimethylarsenic acid (DMA)] in the extracts, while ICP-MS was used to measure total
As content. Arsenic content in the investigated coal wastes and the condensate ranges between 23.3 and 69.3 mg/kg, which are
higher than its reported average content in soils. Arsenic in coal waste exists primarily in the residual fraction; this is
followed in decreasing order by the organic matter-bound, Fe–Mn oxides-bound, exchangeable, carbonates-bound, and water-soluble
fractions. The high content of arsenic in the condensates indicates that combustion or spontaneous combustion is one of the
major ways for arsenic release into the environment from coal waste. About 15% of the arsenic in the condensate sample is
labile and can release into the environment under leaching processes. The water extractable arsenic (WEA) in the fresh coal
waste, fired coal wastes, and the condensate varied between 14.6 and 341 μg/kg, with As(V) as the major species. Furthermore,
both MMA and DMA were found in fresh coal wastes, fired coal wastes, and the condensate. 相似文献
15.
Pankaj Kumar Manish Kumar A. L. Ramanathan Maki Tsujimura 《Environmental geochemistry and health》2010,32(2):129-146
Arsenic contamination in groundwater is of increasing concern because of its high toxicity and widespread occurrence. This
study is an effort to trace the factors responsible for arsenic enrichment in groundwater of the middle Gangetic Plain of
India through major ion chemistry, arsenic speciation, sediment grain-size analyses, and multivariate statistical techniques.
The study focuses on the distinction between the contributions of natural weathering and anthropogenic inputs of arsenic with
its spatial distribution and seasonal variations in the plain of the state Bihar of India. Thirty-six groundwater and one
sediment core samples were collected in the pre-monsoon and post-monsoon seasons. Various graphical plots and statistical
analysis were carried out using chemical data to enable hydrochemical evaluation of the aquifer system based on the ionic
constituents, water types, hydrochemical facies, and factors controlling groundwater quality. Results suggest that the groundwater
is characterized by slightly alkaline pH with moderate to strong reducing nature. The general trend of various ions was found
to be Ca2+ > Na+ > Mg2+ > K+ > NH4
+; and HCO3
− > Cl− > SO4
2− > NO3
− > PO4
3− > F− in both seasons. Spatial and temporal variations showed a slightly higher arsenic concentration in the pre-monsoon period
(118 μg/L) than in the post-monsoon period (114 μg/L). Results of correlation analyses indicate that arsenic contamination
is strongly associated with high concentrations of Fe, PO4
3−, and NH4
+ but relatively low Mn concentrations. Further, the enrichment of arsenic is more prevalent in the proximity of the Ganges
River, indicating that fluvial input is the main source of arsenic. Grain size analyses of sediment core samples revealed
clay (fine-grained) strata between 4.5 and 7.5 m deep that govern the vertical distribution of arsenic. The weathering of
carbonate and silicate minerals along with surface-groundwater interactions, ion exchange, and anthropogenic activities seem
to be the processes governing groundwater contamination, including with arsenic. Although the percentage of wells exceeding
the permissible limit (50 μg/L) was less (47%) than that reported in Bangladesh and West Bengal, the percentage contribution
of toxic As(III) to total arsenic concentration is quite high (66%). This study is vital considering that groundwater is the
exclusive source of drinking water in the region and not only makes situation alarming but also calls for immediate attention. 相似文献
16.
Total concentrations and extractable fractionations of As and Sb were determined in soil samples from former mining sites in Scotland and Italy. Pseudo-total levels of As and Sb in the sample were between 50–17,428 mg/kg and 10–1,187 mg/kg (Scotland), and 16–691 mg/kg and 1.63–11.44 mg/kg (Italy). Between 0.001–0.63% and <0.001−8.82% of the total soil As and Sb, were extractable using, a single extraction bioavailability estimate. Data from an As-specific extraction procedure revealed that up to 60% of As was associated to amorphous Fe-Al oxyhydroxide phase in all soils. A non-specific-sequential extraction test also showed As to be strongly associated with Fe (and Al) oxyhydroxides at both locations. In the case of Sb, in addition to the crystalline Fe-oxide bound Sb the Al-silicate phase also appeared to be significant. At both sites Sb appears to be chemically more accessible than As with consistent availability despite the varied origin and host soil properties. 相似文献
17.
An evaluation of ~250 samples of groundwater in the Amman Zarqa Basin for selenium along with other major and trace elements
showed that concentrations of Se ranged between 0.09 and 742 μg/L, with an average value of about 24 μg/L. Selenium concentrations
exceeded the recommended threshold for drinking water of the World Health Organization (WHO; 10 μ/L of Se) in 114 samples,
with greater than 50 μg/L (quantity equivalent to the Jordanian standard of the allowed concentration of the element in water)
of Se in nine cases. The average concentrations of Se in the lower, middle, and upper aquifers of the basin were 3.41, 32.99,
and 9.19 μg/L, respectively. Based on the correlation with geologic formations and the statistical analysis of major/minor
constituents and Piper tri-linear diagrams, we suggest that carbonate/phosphate dissolution, oxidation–reduction processes,
and fertilizers/irrigation return flow are, together, the primary factors affecting the chemistry of the groundwater. Factor
analysis helped to define the relative role of limestone-dolomitic dissolution in the aquifers (calcium, magnesium, and bicarbonate),
agricultural activities (sulfate, nitrates, phosphorus, and potassium), oxidation–reduction factor (Eh, Fe, Mn, Cu, Zn, and
Se), and anthropogenic (industrial) factor (EC, Fe, Cr, Co, Zn, and As). The high variability in Se concentrations might be
related to the possibility of a multi-source origin of Se in the area. 相似文献
18.
Investigation and risk assessment modeling of As and other heavy metals contamination around five abandoned metal mines in Korea 总被引:3,自引:0,他引:3
Tailings, agricultural soils, vegetables and groundwater samples were collected from abandoned metal mines (Duckum, Dongil,
Dongjung, Myoungbong and Songchun mines) in Korea. Total concentrations of arsenic (As) and heavy metals (Cd, Cu, Pb and Zn)
were analyzed to investigate the contamination level. Several digestion methods (Toxicity characteristics leaching procedure
(TCLP), synthetic precipitation leaching procedure (SPLP), 0.1 N/1 N HCl) and sequential extraction analysis for mine tailings
were conducted to examine the potential leachability of As and heavy metals from the tailings. The order of urgent remediation
for the studied mines based on the risk assessment and remedial goals was suggested.
The Songchun mine tailings were most severely contaminated by As and heavy metals. Total concentrations of As and Pb in the
tailings were 38,600–58,700 mg/kg (av. 47,400 mg/kg) and 11,800–16,800 mg/kg (av. 14,600 mg/kg), respectively. Agricultural
soils having high As concentrations were found at the all mines. Average concentrations of Cd in the vegetables exceeded the
normal value at all mines areas, while As only at the Dongjung, Myoungbong, and Songchun mine area. One groundwater sample
each from the Dongil and Myoungbong mines, and 4 groundwater samples from the Songchun mine had values above 10 μg/L of As
concentration.
The TCLP method revealed that only Pb in the Songchun tailings, 6.49 mg/L, exceeded the regulatory level (5 mg/L). Employing
the 1-N HCl digestion method, the concentration of As in the Songchun mine tailings, 4,250 mg/kg, was up to 3,000 times higher
than its Korean countermeasure standard. Results from the sequential extraction of As in the tailings showed that the easily
releasable fraction in the Myoungbong and Songchun mine tailings was more than 30% and the residual fraction was less than
40%.
Based on results showing the exposure health risk employing the hazard quotient and cancer risk of As, Cd and Zn, the Dongil
mine needs the most urgent remedial action. The concentration reduction factor (CRF) of As in both soil and groundwater follows
the order: Songchun>Dongjung>Dongil>Myoungbong>Duckum mine. 相似文献
19.
Inam E Khantotong S Kim KW Tumendemberel B Erdenetsetseg S Puntsag T 《Environmental geochemistry and health》2011,33(Z1):57-69
The environmental impacts of Boroo gold mine project in Mongolia was evaluated by chemical characterization of trace element concentrations in water, soils and tailing dam sediment samples. The results showed that concentrations of B, Cd, Ni and Se in the water samples were within the accepted levels of the Mongolia water quality standard (MNS4586: 1998). However, the concentrations of Al, As, Cu, Mn, Fe, Pb, U and Zn were higher than the maximum allowable concentration especially in the monitoring and heap leach wells. The average concentrations of As, Cd, Cu, Ni, Pb and Zn in the tailing dam sediment were 4419, 58.5, 56.0, 4.8, 20.6 and 25.7 mg/kg, respectively. Generally, arsenic and heavy metals in the soil samples were within the acceptable concentrations of the soil standard of Mongolia (MNS 5850: 2008). The chemical characterization of As solid phase in tailing dam sediment showed that the majority of As were found in the residual fraction comprising about 74% of total As. Assessing the potential risk to humans, simple bioavailability extraction test was used to estimate bioavailability of arsenic and heavy metals, and the concentrations extracted from tailing dam sediment were; 288.2 mg/kg As, 7.2 mg/kg Cd, 41.1 mg/kg Cu, 13.5 mg/kg Pb, 4.7 mg/kg Ni and 23.5 mg/kg Zn, respectively. From these results, the Boroo gold mine project has presently not significantly impacted the environment, but there is a high probability that it may act as a source of future contamination. 相似文献
20.
M. J. Watts J. O’Reilly A. L. Marcilla R. A. Shaw N. I. Ward 《Environmental geochemistry and health》2010,32(6):479-490
A field method is reported for the speciation of arsenic in water samples that is simple, rapid, safe to use beyond laboratory
environments, and cost effective. The method utilises solid-phase extraction cartridges (SPE) in series for selective retention
of arsenic species, followed by elution and measurement of eluted fractions by inductively coupled plasma mass spectrometry
(ICP-MS) for “total” arsenic. The method is suitable for on-site separation and preservation of arsenic species from water.
Mean percentage accuracies (n = 25) for synthetic solutions of arsenite (AsIII), arsenate (AsV), monomethylarsonic acid (MA), and dimethylarsinic acid (DMA) containing 10 μg l−1 As, were 98, 101, 94, and 105%, respectively. Data are presented to demonstrate the effect of pH and competing anions on
the retention of the arsenic species. The cartridges were tested in the UK and Argentina at sites where arsenic was known
to be present in surface and groundwaters, respectively, at elevated concentrations and under challenging matrix conditions.
In Argentinean groundwater, 4–20% of speciated arsenic was present as MA and 20–73% as AsIII. In UK surface waters, speciated arsenic was measured as 7–49% MA and 12–42% DMA. Comparative data from the field method
using SPE cartridges and the laboratory method using liquid chromatography coupled to ICP-MS for all water samples provided
a correlation of greater than 0.999 for AsIII and DMA, 0.991 for MA, and 0.982 for AsV (P < 0.01). 相似文献