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Sample records for high arsenic groundwaters

  1. Microbial community in high arsenic shallow groundwater aquifers in Hetao Basin of Inner Mongolia, China.

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    Li, Ping; Wang, Yanhong; Dai, Xinyue; Zhang, Rui; Jiang, Zhou; Jiang, Dawei; Wang, Shang; Jiang, Hongchen; Wang, Yanxin; Dong, Hailiang

    2015-01-01

    A survey was carried out on the microbial community of 20 groundwater samples (4 low and 16 high arsenic groundwater) and 19 sediments from three boreholes (two high arsenic and one low arsenic boreholes) in a high arsenic groundwater system located in Hetao Basin, Inner Mongolia, using the 454 pyrosequencing approach. A total of 233,704 sequence reads were obtained and classified into 12-267 operational taxonomic units (OTUs). Groundwater and sediment samples were divided into low and high arsenic groups based on measured geochemical parameters and microbial communities, by hierarchical clustering and principal coordinates analysis. Richness and diversity of the microbial communities in high arsenic sediments are higher than those in high arsenic groundwater. Microbial community structure was significantly different either between low and high arsenic samples or between groundwater and sediments. Acinetobacter, Pseudomonas, Psychrobacter and Alishewanella were the top four genera in high arsenic groundwater, while Thiobacillus, Pseudomonas, Hydrogenophaga, Enterobacteriaceae, Sulfuricurvum and Arthrobacter dominated high arsenic sediments. Archaeal sequences in high arsenic groundwater were mostly related to methanogens. Biota-environment matching and co-inertia analyses showed that arsenic, total organic carbon, SO4(2-), SO4(2-)/total sulfur ratio, and Fe(2+) were important environmental factors shaping the observed microbial communities. The results of this study expand our current understanding of microbial ecology in high arsenic groundwater aquifers and emphasize the potential importance of microbes in arsenic transformation in the Hetao Basin, Inner Mongolia.

  2. Microbial community in high arsenic shallow groundwater aquifers in Hetao Basin of Inner Mongolia, China.

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    Ping Li

    Full Text Available A survey was carried out on the microbial community of 20 groundwater samples (4 low and 16 high arsenic groundwater and 19 sediments from three boreholes (two high arsenic and one low arsenic boreholes in a high arsenic groundwater system located in Hetao Basin, Inner Mongolia, using the 454 pyrosequencing approach. A total of 233,704 sequence reads were obtained and classified into 12-267 operational taxonomic units (OTUs. Groundwater and sediment samples were divided into low and high arsenic groups based on measured geochemical parameters and microbial communities, by hierarchical clustering and principal coordinates analysis. Richness and diversity of the microbial communities in high arsenic sediments are higher than those in high arsenic groundwater. Microbial community structure was significantly different either between low and high arsenic samples or between groundwater and sediments. Acinetobacter, Pseudomonas, Psychrobacter and Alishewanella were the top four genera in high arsenic groundwater, while Thiobacillus, Pseudomonas, Hydrogenophaga, Enterobacteriaceae, Sulfuricurvum and Arthrobacter dominated high arsenic sediments. Archaeal sequences in high arsenic groundwater were mostly related to methanogens. Biota-environment matching and co-inertia analyses showed that arsenic, total organic carbon, SO4(2-, SO4(2-/total sulfur ratio, and Fe(2+ were important environmental factors shaping the observed microbial communities. The results of this study expand our current understanding of microbial ecology in high arsenic groundwater aquifers and emphasize the potential importance of microbes in arsenic transformation in the Hetao Basin, Inner Mongolia.

  3. Microbial Community of High Arsenic Groundwater in Agricultural Irrigation Area of Hetao Plain, Inner Mongolia.

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    Wang, Yanhong; Li, Ping; Jiang, Zhou; Sinkkonen, Aki; Wang, Shi; Tu, Jin; Wei, Dazhun; Dong, Hailiang; Wang, Yanxin

    2016-01-01

    Microbial communities can play important role in arsenic release in groundwater aquifers. To investigate the microbial communities in high arsenic groundwater aquifers in agricultural irrigation area, 17 groundwater samples with different arsenic concentrations were collected along the agricultural drainage channels of Hangjinhouqi County, Inner Mongolia and examined by illumina MiSeq sequencing approach targeting the V4 region of the 16S rRNA genes. Both principal component analysis and hierarchical clustering results indicated that these samples were divided into two groups (high and low arsenic groups) according to the variation of geochemical characteristics. Arsenic concentrations showed strongly positive correlations with [Formula: see text] and total organic carbon (TOC). Sequencing results revealed that a total of 329-2823 operational taxonomic units (OTUs) were observed at the 97% OTU level. Microbial richness and diversity of high arsenic groundwater samples along the drainage channels were lower than those of low arsenic groundwater samples but higher than those of high arsenic groundwaters from strongly reducing areas. The microbial community structure in groundwater along the drainage channels was different from those in strongly reducing arsenic-rich aquifers of Hetao Plain and other high arsenic groundwater aquifers including Bangladesh, West Bengal, and Vietnam. Acinetobacter and Pseudomonas dominated with high percentages in both high and low arsenic groundwaters. Alishewanella, Psychrobacter, Methylotenera, and Crenothrix showed relatively high abundances in high arsenic groundwater, while Rheinheimera and the unidentified OP3 were predominant populations in low arsenic groundwater. Archaeal populations displayed a low occurrence and mainly dominated by methanogens such as Methanocorpusculum and Methanospirillum. Microbial community compositions were different between high and low arsenic groundwater samples based on the results of principal

  4. Microbial Community of High Arsenic Groundwater in Agricultural Irrigation Area of Hetao Plain, Inner Mongolia

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    Wang, Yanhong; Li, Ping; Jiang, Zhou; Sinkkonen, Aki; Wang, Shi; Tu, Jin; Wei, Dazhun; Dong, Hailiang; Wang, Yanxin

    2016-01-01

    Microbial communities can play important role in arsenic release in groundwater aquifers. To investigate the microbial communities in high arsenic groundwater aquifers in agricultural irrigation area, 17 groundwater samples with different arsenic concentrations were collected along the agricultural drainage channels of Hangjinhouqi County, Inner Mongolia and examined by illumina MiSeq sequencing approach targeting the V4 region of the 16S rRNA genes. Both principal component analysis and hierarchical clustering results indicated that these samples were divided into two groups (high and low arsenic groups) according to the variation of geochemical characteristics. Arsenic concentrations showed strongly positive correlations with NH4+ and total organic carbon (TOC). Sequencing results revealed that a total of 329–2823 operational taxonomic units (OTUs) were observed at the 97% OTU level. Microbial richness and diversity of high arsenic groundwater samples along the drainage channels were lower than those of low arsenic groundwater samples but higher than those of high arsenic groundwaters from strongly reducing areas. The microbial community structure in groundwater along the drainage channels was different from those in strongly reducing arsenic-rich aquifers of Hetao Plain and other high arsenic groundwater aquifers including Bangladesh, West Bengal, and Vietnam. Acinetobacter and Pseudomonas dominated with high percentages in both high and low arsenic groundwaters. Alishewanella, Psychrobacter, Methylotenera, and Crenothrix showed relatively high abundances in high arsenic groundwater, while Rheinheimera and the unidentified OP3 were predominant populations in low arsenic groundwater. Archaeal populations displayed a low occurrence and mainly dominated by methanogens such as Methanocorpusculum and Methanospirillum. Microbial community compositions were different between high and low arsenic groundwater samples based on the results of principal coordinate

  5. Characteristics of high arsenic groundwater in Hetao Basin, Inner Mongolia, northern China

    Institute of Scientific and Technical Information of China (English)

    YangChun Zhu; XueYong Zhao; Min Chen; YongQing Luo; Xin Zhou

    2015-01-01

    It is well known that the Hetao Basin is one of the most seriously arsenic-affected groundwater areas in China. In order to understand the characteristics of high arsenic (As) groundwater in the Basin, a brief overview of arsenic in groundwater follows. High arsenic in the Basin commonly occurs in shallow groundwater and the total arsenic concentrations range from 0.58 to 572 µg/L (average 99.73 µg/L), exceeding the maximum mandated value of 10 µg/L for drinking water in China;As(Ш) is the predominant species. The regional distribution pattern of arsenic in the groundwater increases from south/southeast to north/northwest. Hangjinhouqi and Wuyuan counties are considered as the most seriously affected areas, with high incidences of endemic arsenicosic diseases in the Hetao Basin. High groundwater arsenic correlates with the increase of well depth. Previous studies proposed that groundwater arsenic in the Basin is mainly originated from desorption of some natural solid materials in the sediments, under reducing condition. Generally, reducing condition is believed to be the primary factor for arsenic releasing from the sediment to groundwater in the region. Under inorganic or bacterial processes, Fe2O3 changes to FeS and arsenic adsorbed to Fe(OH)3 dissolves into groundwater, and As(V) is re-duced to As(Ш). Besides, reducing environments, groundwater hydraulic gradients, organic matter, pH, evapotranspiration, and soil texture are presumed to be the predominant factors that control arsenic mobilization.

  6. Environmental geochemistry of high arsenic groundwater at western Hetao plain, Inner Mongolia

    Institute of Scientific and Technical Information of China (English)

    Jun HE; Teng MA; Yamin DENG; Hui YANG; Yanxin WANG

    2009-01-01

    Environmental geochemistry of high arsenic groundwater at Hetao plain was studied on the basis of geochemical survey of the groundwater and a core sediment. Arsenic concentration in groundwater samples varies from 76 to 1093 μg/L. The high arsenic groundwater mostly appears to be weakly alkaline. The concentrations of NO3 and SO42- are relatively low, while the concentrations ofDOC, NH4+, dissolved Fe and sulfide are relatively great. Analysis of arsenic speciation in 21 samples shows that arsenic is present in the solution predominantly as As(Ⅲ), while particulate arsenic constitutes about 10% of the total arsenic. Methane is detected in five samples with the greatest content being 5107 μg/L.The shallow aquifer in Hangjinhouqi of western Hetao plain is of strongly reducing condition. The arsenic content in 23 core sediment samples varies from 7.7 to 34.6 mg/kg, with great value in clay and mild clay layer. The obvious positive relationship in content between Fe203, Mn, Sb, B, V and As indicates that the distribution of arsenic in the sediments may be related to Fe and Mn oxides, and the mobilization of Sb, B and V may be affected by similar geochemical processes as that of As.

  7. Isotopic evidence for a link between agricultural irrigation and high arsenic concentrations in groundwater

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    Li, M.; Wang, Y.; Shock, E.

    2011-12-01

    An isotope-based survey was carried out in the Datong Basin, northern China to investigate the hydrogeology of groundwater with high arsenic concentrations. Oxygen isotope (δ18O), hydrogen isotope (δD) and radioactive hydrogen isotope (3H) measurements were conducted with the aim of characterizing the groundwater origins and flow dynamics in this arsenic-contaminated groundwater system. Groundwater dating results from 3H measurements show that groundwaters from 20m ~ 70m have a wide range of ages (10a~ 191a), indicating diverse groundwater sources. In contrast, deeper groundwaters (70m ~90m) display a narrower age range (35a ~ 47a). In addition, the shallow-aquifer (70m) possess relatively narrower isotopic ranges and mostly lighter isotopic ratios, from -12.8% to -8.88% and -97.6% to -71.7%, respectively. Comparison with the local meteoric water line shows that groundwater δ18O and δD values plot with a shallower slope, consistent with the arid-semiarid climate of the Datong Basin, as well as a meteoric origin of the groundwater, and points to precipitation as the dominant source of recharge to the deeper aquifers in the study area. Groundwaters with high arsenic concentrations (100μg/L ~ 309μg/L) mainly occur in aquifers at depths between 20m and 70m, while shallower (70m) groundwaters carry relatively lower arsenic concentrations (Science of the Total Environment 407(12): 3823-3835.

  8. ARSENIC CONTAMINATION IN GROUNDWATER: A STATISTICAL MODELING

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    Palas Roy

    2013-01-01

    Full Text Available High arsenic in natural groundwater in most of the tubewells of the Purbasthali- Block II area of Burdwan district (W.B, India has recently been focused as a serious environmental concern. This paper is intending to illustrate the statistical modeling of the arsenic contaminated groundwater to identify the interrelation of that arsenic contain with other participating groundwater parameters so that the arsenic contamination level can easily be predicted by analyzing only such parameters. Multivariate data analysis was done with the collected groundwater samples from the 132 tubewells of this contaminated region shows that three variable parameters are significantly related with the arsenic. Based on these relationships, a multiple linear regression model has been developed that estimated the arsenic contamination by measuring such three predictor parameters of the groundwater variables in the contaminated aquifer. This model could also be a suggestive tool while designing the arsenic removal scheme for any affected groundwater.

  9. Arsenic geochemistry of groundwater in Southeast Asia.

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    Kim, Kyoung-Woong; Chanpiwat, Penradee; Hanh, Hoang Thi; Phan, Kongkea; Sthiannopkao, Suthipong

    2011-12-01

    The occurrence of high concentrations of arsenic in the groundwater of the Southeast Asia region has received much attention in the past decade. This study presents an overview of the arsenic contamination problems in Vietnam, Cambodia, Lao People's Democratic Republic and Thailand. Most groundwater used as a source of drinking water in rural areas has been found to be contaminated with arsenic exceeding the WHO drinking water guideline of 10 μg·L(-1). With the exception of Thailand, groundwater was found to be contaminated with naturally occurring arsenic in the region. Interestingly, high arsenic concentrations (> 10 μg·L(-1)) were generally found in the floodplain areas located along the Mekong River. The source of elevated arsenic concentrations in groundwater is thought to be the release of arsenic from river sediments under highly reducing conditions. In Thailand, arsenic has never been found naturally in groundwater, but originates from tin mining activities. More than 10 million residents in Southeast Asia are estimated to be at risk from consuming arsenic-contaminated groundwater. In Southeast Asia, groundwater has been found to be a significant source of daily inorganic arsenic intake in humans. A positive correlation between groundwater arsenic concentration and arsenic concentration in human hair has been observed in Cambodia and Vietnam. A substantial knowledge gap exists between the epidemiology of arsenicosis and its impact on human health. More collaborative studies particularly on the scope of public health and its epidemiology are needed to conduct to fulfill the knowledge gaps of As as well as to enhance the operational responses to As issue in Southeast Asian countries.

  10. Arsenic contamination of the soil-wheat system irrigated with high arsenic groundwater in the Hetao Basin, Inner Mongolia, China.

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    Tong, Junting; Guo, Huaming; Wei, Chao

    2014-10-15

    As one of the most important crop in the world, wheat (Triticum aestivum L.) was irrigated with low As water and high As water. However, little is known about As cycling in the soil-wheat-water system. Two wheat fields (site G and site Y), irrigated with high dissolved As (178 μg L(-1)) groundwater and low dissolved As (8.2 μg L(-1)) surface water, respectively, were systematically sampled in the Hetao Basin, including irrigation water, soils and plants. The annual As (including dissolved As and suspended As) input per m(2) was estimated at 140 and 36.7 mg in site G and site Y, respectively. Topsoils of site G contained relatively higher As content (average 18.8 mg kg(-1)) than those of site Y (13.8 mg kg(-1)). Arsenic content of wheat grains in site G is systematically higher than in the site Y, which were positively correlated with non-specifically sorbed-As and amorphous Fe/Al oxide-bound As in topsoils. Arsenic-contaminated groundwater led to As accumulation in irrigated soils and the increase in As bioavailability, and subsequently resulted in the increase in As content of wheat grain. It suggested that less problematic water resources should be used for wheat irrigation in order to avoid As accumulation in the soil-plant system. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Effectiveness of household reverse-osmosis systems in a Western U.S. region with high arsenic in groundwater

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    Walker, M.; Seiler, R.L.; Meinert, M.

    2008-01-01

    It is well known to the public in Lahontan Valley in rural Nevada, USA, that local aquifers produce water with varied, but sometimes very high concentrations of arsenic (> 4??ppm). As a result, many residents of the area have installed household reverse-osmosis (RO) systems to produce drinking water. We examined performance of RO systems and factors associated with arsenic removal efficiency in 59 households in Lahontan Valley. The sampling results indicated that RO systems removed an average of 80.2% of arsenic from well water. In 18 of the 59 households, arsenic concentrations exceeded 10??ppb in treated water, with a maximum in treated water of 180??ppb. In 3 of the 59 households, RO treatment had little effect on specific conductance, indicating that the RO system was not working properly. Two main factors lead to arsenic levels in treated water exceeding drinking-water standards in the study area. First, arsenic concentrations were high enough in some Lahontan Valley wells that arsenic levels exceeded 10??ppb even though RO treatment removed more than 95% of the arsenic. Second, trivalent As+ 3 was the dominant arsenic species in approximately 15% of the wells, which significantly reduced treatment efficiency. Measurements of specific conductance indicated that efficiency in reducing arsenic levels did not always correlate with reductions in total dissolved solids. As a consequence, improvements in taste of the water or simple measurements of specific conductance made by technicians to test RO systems can mislead the public into assuming the water meets safety standards. Actual measurements of treated water are necessary to assure that household RO systems are reducing arsenic concentrations to safe levels, particularly in areas where groundwater has high arsenic concentrations or where As+ 3 is the dominant species. ?? 2007 Elsevier B.V. All rights reserved.

  12. Groundwater arsenic contamination throughout China.

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    Rodríguez-Lado, Luis; Sun, Guifan; Berg, Michael; Zhang, Qiang; Xue, Hanbin; Zheng, Quanmei; Johnson, C Annette

    2013-08-23

    Arsenic-contaminated groundwater used for drinking in China is a health threat that was first recognized in the 1960s. However, because of the sheer size of the country, millions of groundwater wells remain to be tested in order to determine the magnitude of the problem. We developed a statistical risk model that classifies safe and unsafe areas with respect to geogenic arsenic contamination in China, using the threshold of 10 micrograms per liter, the World Health Organization guideline and current Chinese standard for drinking water. We estimate that 19.6 million people are at risk of being affected by the consumption of arsenic-contaminated groundwater. Although the results must be confirmed with additional field measurements, our risk model identifies numerous arsenic-affected areas and highlights the potential magnitude of this health threat in China.

  13. Establishment of Groundwater Arsenic Potential Distribution and Discrimination in Taiwan

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    Tsai, Kuo Sheng; Chen, Yu Ying; Chung Liu, Chih; Lin, Chien Wen

    2016-04-01

    According to the last 10 years groundwater monitoring data in Taiwan, Arsenic concentration increase rapidly in some areas, similar to Bengal and India, the main source of Arsenic-polluted groundwater is geological sediments, through reducing reactions. There are many researches indicate that high concentration of Arsenic in groundwater poses the risk to water safety, for example, the farm lands irrigation water contains Arsenic cause the concentration of Arsenic increase in soil and crops. Based on the management of water usage instead of remediation in the situation of insufficient water. Taiwan EPA has been developed the procedures of Arsenic contamination potential area establishment and source discriminated process. Taiwan EPA use the procedures to determine the management of using groundwater, and the proposing usage of Arsenic groundwater accordance with different objects. Agencies could cooperate with the water quality standard or water needs, studying appropriate water purification methods and the groundwater depth, water consumption, thus achieve the goal of water safety and environmental protection, as a reference of policy to control total Arsenic concentration in groundwater. Keywords: Arsenic; Distribution; Discrimination; Pollution potential area of Arsenic; Origin evaluation of groundwater Arsenic

  14. Geochemistry of redox-sensitive elements and sulfur isotopes in the high arsenic groundwater system of Datong Basin, China.

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    Xie, Xianjun; Ellis, Andre; Wang, Yanxin; Xie, Zuoming; Duan, Mengyu; Su, Chunli

    2009-06-01

    High arsenic groundwater in the Quaternary aquifers of Datong Basin, northern China contain As up to 1820 microg/L and the high concentration plume is located in the slow flowing central parts of the basin. In this study we used hydrochemical data and sulfur isotope ratios of sulfate to better understand the conditions that are likely to control arsenic mobilization. Groundwater and spring samples were collected along two flow paths from the west and east margins of the basin and a third set along the basin flow path. Arsenic concentrations range from 68 to 670 microg/L in the basin and from 3.1 to 44 microg/L in the western and eastern margins. The margins have relatively oxidized waters with low contents of arsenic, relatively high proportions of As(V) among As species, and high contents of sulfate and uranium. By contrast, the central parts of the basin are reducing with high contents of arsenic in groundwater, commonly with high proportions of As(III) among As species, and low contents of sulfate and uranium. No statistical correlations were observed between arsenic and Eh, sulfate, Fe, Mn, Mo and U. While the mobility of sulfate, uranium and molybdenum is possibly controlled by the change in redox conditions as the groundwater flows towards central parts of the basin, the reducing conditions alone cannot account for the occurrence of high arsenic groundwater in the basin but it does explain the characteristics of arsenic speciation. With one exception, all the groundwaters with As(III) as the major As species have low Eh and those with As(V) have high Eh. Reductive dissolution of Fe-oxyhydroxides or reduction of As(V) are consistent with the observations, however no increase in dissolved Fe concentration was noted. Furthermore, water from the well with the highest arsenic was relatively oxidizing and contained mostly As(V). From previous work Fe-oxyhydroxides are speculated to exist as coatings rather than primary minerals. The wide range of delta(34)S([SO4

  15. Arsenic and Associated Trace Metals in Texas Groundwater

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    Lee, L.; Herbert, B. E.

    2002-12-01

    The value of groundwater has increased substantially worldwide due to expanding human consumption. Both the quantity and quality of groundwater are important considerations when constructing policies on natural resource conservation. This study is focused on evaluating groundwater quality in the state of Texas. Historical data from the Texas Water Development Board and the National Uranium Resource Evaluation were collected into a GIS database for spatial and temporal analyses. Specific attentions were placed on arsenic and other trace metals in groundwater. Recent studies in the United States have focused on isolated incidences of high arsenic occurrence, ignoring possible connections between arsenic and other trace metals. Descriptive statistics revealed strong correlations in groundwater between arsenic and other oxyanions including vanadium, selenium and molybdenum. Arsenic and associated trace metals were clustered at three physiographic hotspots, the Southern High Plains, the Gulf Coastal Plains of Texas, and West Texas. A geologic survey showed that arsenic and other trace metals in Texas groundwater follow local geologic trends. Uranium deposits and associated mineralization were found to occur in the same physiographic locations. Uranium mineralization may be a significant natural source of arsenic and other trace metals in Texas groundwater. Recharge, evaporative concentration, and aquifer characteristics were also contributing factors to the occurrence of trace metals in Texas groundwater. Spatial statistics were used to delineate natural sources from anthropogenic inputs. Similarly, the natural background was estimated from the spatial distribution of trace metal observations in Texas groundwater.

  16. Arsenic Speciation in Groundwater: Role of Thioanions

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    The behavior of arsenic in groundwater environments is fundamentally linked to its speciation. Understanding arsenic speciation is important because chemical speciation impacts reactivity, bioavailability, toxicity, and transport and fate processes. In aerobic environments arsen...

  17. Arsenic Contamination in Food-chain: Transfer of Arsenic into Food Materials through Groundwater Irrigation

    Science.gov (United States)

    Joardar, J.C.; Parvin, S.; Correll, Ray; Naidu, Ravi

    2006-01-01

    Arsenic contamination in groundwater in Bangladesh has become an additional concern vis-à-vis its use for irrigation purposes. Even if arsenic-safe drinking-water is assured, the question of irrigating soils with arsenic-laden groundwater will continue for years to come. Immediate attention should be given to assess the possibility of accumulating arsenic in soils through irrigation-water and its subsequent entry into the food-chain through various food crops and fodders. With this possibility in mind, arsenic content of 2,500 water, soil and vegetable samples from arsenic-affected and arsenic-unaffected areas were analyzed during 1999–2004. Other sources of foods and fodders were also analyzed. Irrigating a rice field with groundwater containing 0.55 mg/L of arsenic with a water requirement of 1,000 mm results in an estimated addition of 5.5 kg of arsenic per ha per annum. Concentration of arsenic as high as 80 mg per kg of soil was found in an area receiving arsenic-contaminated irrigation. A comparison of results from affected and unaffected areas revealed that some commonly-grown vegetables, which would usually be suitable as good sources of nourishment, accumulate substantially-elevated amounts of arsenic. For example, more than 150 mg/kg of arsenic has been found to be accumulated in arum (kochu) vegetable. Implications of arsenic ingested in vegetables and other food materials are discussed in the paper. PMID:17366772

  18. Quality of our groundwater resources: arsenic and fluoride

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    Nordstrom, D. Kirk

    2011-01-01

    Groundwater often contains arsenic or fluoride concentrations too high for drinking or cooking. These constituents, often naturally occurring, are not easy to remove. The right combination of natural or manmade conditions can lead to elevated arsenic or fluoride which includes continental source rocks, high alkalinity and pH, reducing conditions for arsenic, high phosphate, high temperature and high silica. Agencies responsible for safe drinking water should be aware of these conditions, be prepared to monitor, and treat if necessary.

  19. Abundance and diversity of methanogens: potential role in high arsenic groundwater in Hetao Plain of Inner Mongolia, China.

    Science.gov (United States)

    Wang, Y H; Li, P; Dai, X Y; Zhang, R; Jiang, Z; Jiang, D W; Wang, Y X

    2015-05-15

    To investigate the community diversity and abundance of methanogens and their potential role in high arsenic groundwater, 17 groundwater samples from Hetao Plain of Inner Mongolia were investigated with an integrated method including 16S rRNA gene clone library, quantitative polymerase chain reaction and geochemistry analyses. Total arsenic (AsTot) concentrations were 82.7-1088.7 μg/L and arsenite (AsIII) mostly dominated in these samples with percentages of 0.04-0.79. CH₄ concentrations ranged from 0.01 to 292 μg/L and distinctly elevated only when AsTot were relatively high and SO₄(2-) were distinctly low. Principal component analysis indicated that these samples were divided into three groups according to the variations of AsTot, CH₄ and SO₄(2-). AsTot concentrations were distinctly high in the group with high CH₄ and low SO₄(2-) comparing to the other two groups (one with high CH₄ and high SO₄(2-), the other with low CH₄ and SO₄(2-)). The mcrA gene (methyl coenzyme-M reductase gene) based phylogenetic analysis of methanogens population showed that methanogenic archaea was diverse but mainly composed of Methanomicrobiales, Methanosarcinales, Methanobacteria and unidentified groups, with Methanomicrobiales being distinctly dominant (50.6%). The mcrA gene abundance in high arsenic groundwater ranged from 3.01 × 10(3) to 3.80 × 10(6)copies/L and accounted for 0-30.2% of total archaeal 16S rRNA genes. The abundance of mcrA genes was positively correlated with the concentrations of AsTot (R=0.59), AsIII (R=0.57) and FeII (R=0.79), while it was negatively correlated with oxidation-reduction potential (R=-0.66) and SO₄(2-) concentration (R=-0.64). These results implied that methanogenic archaea might accelerate As release in groundwater aquifers in Hetao Plain.

  20. Arsenic Mobility and Groundwater Extraction in Bangladesh

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    Harvey, Charles F.; Swartz, Christopher H.; Badruzzaman, A. B. M.; Keon-Blute, Nicole; Yu, Winston; Ali, M. Ashraf; Jay, Jenny; Beckie, Roger; Niedan, Volker; Brabander, Daniel; Oates, Peter M.; Ashfaque, Khandaker N.; Islam, Shafiqul; Hemond, Harold F.; Ahmed, M. Feroze

    2002-11-01

    High levels of arsenic in well water are causing widespread poisoning in Bangladesh. In a typical aquifer in southern Bangladesh, chemical data imply that arsenic mobilization is associated with recent inflow of carbon. High concentrations of radiocarbon-young methane indicate that young carbon has driven recent biogeochemical processes, and irrigation pumping is sufficient to have drawn water to the depth where dissolved arsenic is at a maximum. The results of field injection of molasses, nitrate, and low-arsenic water show that organic carbon or its degradation products may quickly mobilize arsenic, oxidants may lower arsenic concentrations, and sorption of arsenic is limited by saturation of aquifer materials.

  1. High soil and groundwater arsenic levels induce high body arsenic loads, health risk and potential anemia for inhabitants of northeastern Iran.

    Science.gov (United States)

    Taheri, Masumeh; Mehrzad, Jalil; Mahmudy Gharaie, Mohamad Hosein; Afshari, Reza; Dadsetan, Ahmad; Hami, Shakiba

    2016-04-01

    Arsenic bioavailability in rock, soil and water resources is notoriously hazardous. Geogenic arsenic enters the body and adversely affects many biochemical processes in animals and humans, posing risk to public health. Chelpu is located in NE Iran, where realgar, orpiment and pyrite mineralization is the source of arsenic in the macroenvironment. Using cluster random sampling strategy eight rocks, 23 soils, 12 drinking water resources, 36 human urine and hair samples and 15 adult sheep urine and wool samples in several large-scale herds in the area were randomly taken for quantification of arsenic in rock/soil/water, wool/hair/urine. Arsenic levels in rock/soil/water and wool/hair/urine were measured using inductively coupled plasma spectroscopy and atomic absorption spectrophotometry, respectively. While arsenic levels in rocks, soils and water resources hazardously ranged 9.40-25,873.3 mg kg(-1), 7.10-1448.80 mg kg(-1) and 12-606 μg L(-1), respectively, arsenic concentrations in humans' hair and urine and sheep's wool and urine varied from 0.37-1.37 μg g(-1) and 9-271.4 μg L(-1) and 0.3-3.11 μg g(-1) and 29.1-1015 μg L(-1), respectively. Local sheep and human were widely sick and slightly anemic. Hematological examination of the inhabitants revealed that geogenic arsenic could harm blood cells, potentially resulting in many other hematoimmunological disorders including cancer. The findings warn widespread exposure of animals and human in this agroecologically and geopolitically important region (i.e., its proximity with Afghanistan, Pakistan and Turkmenistan) and give a clue on how arsenic could induce infectious and non-infectious diseases in highly exposed human/animals.

  2. Investigating groundwater arsenic contamination using aquifer push-pull test

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    Daigle, A. R.; Jin, Q.

    2009-12-01

    The groundwater of the Southern Willamette Basin, OR is contaminated with arsenic at concentrations as high as several ppm. A single-well push-pull test was conducted to investigate how microbial metabolisms control arsenic occurrence and levels in the bedrock aquifer of the area. During the experiments, a test solution containing ethanol was first injected into the aquifer. As the experiment progressed, dissolved gasses, groundwater, and sediment were sampled to monitor the variations in the chemical parameters, including the speciation of iron, sulfur, and arsenic, in the aquifer. Ethanol amendment stimulated a series of microbial metabolisms, including arsenate reduction, iron reduction, and sulfate reduction. Iron reduction released arsenic sorbed onto the aquifer sediments, increasing groundwater arsenic levels. Arsenate reduction converted arsenate to arsenite and, as a result, most arsenic occurred as arsenite in the groundwater. Results of the experiments demonstrate how different microbial functional groups influenced arsenic contamination in the area. These results also shed new light on potential bioremediation strategies in the area.

  3. Spatial variability and prediction modeling of groundwater arsenic distributions in the shallowest alluvial aquifers in Bangladesh

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    Shamsudduha, M.

    2007-01-01

    Elevated arsenic in groundwater is the greatest environmental problem in Bangladesh. Spatial variability of arsenic in groundwater has been examined by semivariogram analysis that revealed high degree of small-scale spatial variability in alluvial aquifers. Small-scale variability of arsenic concentrations, indicated by high "nugget" values in semivariograms, is associated with heterogeneity in local-scale geology and geochemical processes. In unsampled locations, arsenic concentrations have ...

  4. [Study on the variation of arsenic concentration in groundwater and chemical characteristics of arsenic in sediment cores at the areas with endemic arsenic poison disease in Jianghan Plain].

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    Zhou, Suhua; Ye, Hengpeng; Li, Mingjian; Xiong, Peisheng; Du, Dongyun; Wang, Jingwen

    2015-06-01

    To understand the variation of arsenic concentration in underground water at the endemic arsenic poison disease area of Jianghan Plain so as to better understand the spatial distribution of high arsenic groundwater, hydro-chemical evolution and source of arsenic in this region. Thirty underground water samples were collected respectively around 3 km radius of the two houses where arsenic poisoning patients lived, in Xiantao and Honghu. Sediment cores of three drillings were collected as well. Both paired t-test or paired Wilcoxon Signed Ranking Test were used to compare the arsenic concentration of water. The arsenic concentration in 2011-2012 appeared lower than that in 2006-2007 at the Nanhong village of Xiantao (t = 4.645 3, P arsenic concentration and Cl, HCO3(-), Fe, Mn. However, negative correlations were found between As and SO4(2-), NO3(-). The range of arsenic content in the sediment was 1.500 mg/kg to 17.289 mg/kg. The maximum arsenic content existed in the soil layer, while the minimum arsenic content existed in the sand layer. The concentration of arsenic varied widely with time and space at endemic arsenic poison disease area of Jianghan Plain. Characteristics of these water chemicals showed significant differences, when compared to the groundwater from Datong Basin, Shanxi Shanyin and Hetao Plain of Inner Mongolia, which presented a typical environment with high arsenic contents in the groundwater. The arsenic content in the sediment samples seemed related to the lithologic structure.

  5. Management of the Arsenic Groundwater System Lagunera - MEXICO

    Science.gov (United States)

    Boochs, P. W.; Billib, M.; Aparicio, J.; Gutierrez, C.

    2007-05-01

    mixing of "young" water with less arsenic and "old" water with high arsenic was excluded, which results in the long term to higher arsenic concentrations in the groundwater. In order to understand the actual situation and to prognosticate the further development of the arsenic concentration in the Comarca Lagunera region, it was necessary to reproduce the historical development with a simulation model which includes the different anthropogenic impacts. For this purpose the groundwater model MODFLOW was used and the investigation area of about 7000 sq km was divided by a regular square grid with a mesh size of 1 km. The calibration of the model started with steady state conditions, using an assumed, uninfluenced "original status" of 1900. Subsequently, the influence of the immensely rising groundwater discharge beginning 1950 and the canalization of the river Nazas were simulated and the results were compared with measurements at selected times. The prognostic calculations showed, that the increase of the arsenic concentration will go on in the future under the present conditions of overpumping. Therefore, it has to be reduced. To control the arsenic migration towards the urban wells for dringking water supply artificial recharge can be done. Another possibility is a treatment, especially subterranean, of arsenic or to use surface water for drinking water purposes.

  6. Groundwater Arsenic Contamination in Kopruoren Basin (Kutahya), Turkey

    Science.gov (United States)

    Arslan, S.; Dokuz, U.; Celik, M.; Cheng, Z.

    2012-12-01

    Groundwater quality in the Kopruoren Basin located to the west of Kutahya city in western Anatolia was investigated. Kopruoren Basin is about 275 km2 with about 6,000 residents, but the surface and ground-water quality in this basin impacts a much larger population since the area is located upstream of Kutahya and Eskisehir plains. Groundwater occurs under confined conditions in the limestones of Pliocene units. The only silver deposit of Turkey is developed in the metamorphic basement rocks, Early Miocene volcanics and Pliocene units near Gumuskoy. The amount of silver manufactured annually comprises about 1% of the World's Silver Production. The cyanide-rich wastes of the Eti Gumus silver plant is stored in waste pools. There have been debates about the safety of this facility after a major collapse occurred in one of the pools in May 2011. In this study samples from 31 wells and 21 springs were collected in July and October 2011 and May 2012. The groundwaters are of Ca-Mg-HCO3 type, with arsenic, zinc and antimony occurring at high concentrations. Dissolved arsenic concentrations are as high as 48 ug/L in springs and 734 ug/L in well water. Arsenic in 57% of the springs and 68% of the wells exceeded the WHO guideline value (10 ug/L). Natural sources of arsenic in the area include the dissolution of arsenic-rich minerals such as realgar and orpiment associated with the mineral deposits in the southern part of the study area. In the northern part, arsenic is enriched due to the dissolution of arsenic-bearing coal deposits. Besides these natural sources of contamination, the silver mining activity could be an important anthropogenic source. The leakage of cyanide and arsenic, together with other trace elements to the environment from the waste pools, will continue to poison the environment if necessary precautions are not taken immediately.

  7. Arsenic poisoning of Bangladesh groundwater

    Science.gov (United States)

    Nickson, Ross; McArthur, John; Burgess, William; Ahmed, Kazi Matin; Ravenscroft, Peter; Rahmanñ, Mizanur

    1998-09-01

    In Bangladesh and West Bengal, alluvial Ganges aquifers used for public water supply are polluted with naturally occurring arsenic, which adversely affects the health of millions of people. Here we show that the arsenic derives from the reductive dissolution of arsenic-rich iron oxyhydroxides, which in turn are derived from weathering of base-metal sulphides. This finding means it should now be possible, by sedimentological study of the Ganges alluvial sediments, to guide the placement of new water wells so they will be free of arsenic.

  8. Naturally occurring arsenic in the groundwater at the Kansas City Plant

    Energy Technology Data Exchange (ETDEWEB)

    Korte, N.E.

    1990-12-01

    This report describes an investigation concerning the presence of arsenic in concentrations exceeding 0.4 mg/L in the groundwater under the Department of Energy's Kansas City Plant (KCP). The study consisted of four distinct phases: a thorough review of the technical literature, a historical survey of arsenic use at the facility, a laboratory study of existing techniques for determining arsenic speciation, and a field program including water, soil, and sediment sampling. The historical survey and literature review demonstrated that plant activities had not released significant quantities of arsenic to the environment but that similar occurrences of arsenic in alluvial groundwater are widespread in the midwestern United States. Laboratory studies showed that a chromatographic separation technique was necessary to accurately determine arsenic speciation for the KCP groundwater samples. Field studies revealed that naturally occurring reducing conditions prevalent in the subsurface are responsible for dissolving arsenic previously sorbed by iron oxides. Indeed, the data demonstrated that the bulk arsenic concentration of site subsoils and sediments is {approximately}7 mg/kg, whereas the arsenic content of iron oxide subsamples is as high as 84 mg/kg. Literature showed that similar concentrations of arsenic in sediments occur naturally and are capable of producing the levels of arsenic found in groundwater monitoring wells at the KCP. The study concludes, therefore, that the arsenic present in the KCP groundwater is the result of natural phenomena. 44 refs., 8 figs., 14 tabs.

  9. Distribution of arsenic in groundwater in the area of Chalkidiki, Northern Greece.

    Science.gov (United States)

    Kouras, A; Katsoyiannis, I; Voutsa, D

    2007-08-25

    An integrate study aiming at the occurrence and distribution of arsenic in groundwater in the area of Chalkidiki, Northern Greece has been carried out. Groundwater samples from public water supply wells and private wells were analysed for arsenic and other quality parameters (T, pH, EC, Ca, Mg, Na, K, Cl, HCO(3), NO(3), SO(4), B, Fe, Mn). Arsenic showed high spatial variation; ranged from 0.001 to 1.840mg/L. Almost 65% of the examined groundwaters exhibit arsenic concentrations higher than the maximum concentration limit of 0.010mg/L, proposed for water intended for human consumption. Correlation analysis and principal component analysis were employed to find out possible relationships among the examined parameters and groundwater samples. Arsenic is highly correlated with potassium, boron, bicarbonate, sodium, manganese and iron suggesting common geogenic origin of these elements and conditions that enhance their mobility. Three groups of groundwater with different physicochemical characteristics were found in the study area: (a) groundwater with extremely high arsenic concentrations (1.6-1.9mg/L) and high temperature (33-42 degrees C) from geothermal wells, (b) groundwater with relatively high arsenic concentrations (>0.050mg/L), lower temperatures and relatively high concentrations of major ions, iron and manganese and, (c) groundwater with low arsenic concentrations that fulfil the proposed limits for dinking water.

  10. Arsenic and fluoride in the groundwater of Mexico.

    Science.gov (United States)

    Armienta, M A; Segovia, N

    2008-08-01

    Concentrations of arsenic and fluoride above Mexican drinking water standards have been detected in aquifers of various areas of Mexico. This contamination has been found to be mainly caused by natural sources. However, the specific processes releasing these toxic elements into groundwater have been determined in a few zones only. Many studies, focused on arsenic-related health effects, have been performed at Comarca Lagunera in northern México. High concentrations of fluoride in water were also found in this area. The origin of the arsenic there is still controversial. Groundwater in active mining areas has been polluted by both natural and anthropogenic sources. Arsenic-rich minerals contaminate the fractured limestone aquifer at Zimapán, Central México. Tailings and deposits smelter-rich fumes polluted the shallow granular aquifer. Arsenic contamination has also been reported in the San Antonio-El Triunfo mining zone, southern Baja California, and Santa María de la Paz, in San Luis Potosí state. Even in the absence of mining activities, hydrogeochemistry and statistical techniques showed that arsenopyrite oxidation may also contaminate water, as in the case of the Independencia aquifer in the Mexican Altiplano. High concentrations of arsenic have also been detected in geothermal areas like Los Azufres, Los Humeros, and Acoculco. Prevalence of dental fluorosis was revealed by epidemiological studies in Aguascalientes and San Luis Potosí states. Presence of fluoride in water results from dissolution of acid-volcanic rocks. In Mexico, groundwater supplies most drinking water. Current knowledge and the geology of Mexico indicate the need to include arsenic and fluoride determinations in groundwater on a routine basis, and to develop interdisciplinary studies to assess the contaminant's sources in all enriched areas.

  11. Groundwater arsenic contamination throughout China

    National Research Council Canada - National Science Library

    Rodríguez-Lado, Luis; Sun, Guifan; Berg, Michael; Zhang, Qiang; Xue, Hanbin; Zheng, Quanmei; Johnson, C Annette

    2013-01-01

    .... We developed a statistical risk model that classifies safe and unsafe areas with respect to geogenic arsenic contamination in China, using the threshold of 10 micrograms per liter, the World Health...

  12. Effects of recharge and discharge on delta2H and delta18O composition and chloride concentration of high arsenic/fluoride groundwater from the Datong Basin, northern China.

    Science.gov (United States)

    Xie, Xianjun; Wang, Yanxin; Su, Chunli; Duan, Mengyu

    2013-02-01

    To better understand the effects of recharge and discharge on the hydrogeochemistry of high levels of arsenic (As) and fluoride (F) in groundwater, environmental isotopic composition (delta2H and delta18O) and chloride (Cl) concentrations were analyzed in 29 groundwater samples collected from the Datong Basin. High arsenic groundwater samples (As > 50 micog/L) were found to be enriched in lighter isotopic composition that ranged from -92 to -78 per thousand for deuterium (delta2H) and from -12.5 to -9.9 per thousand for oxygen-18 (delta18O). High F-containing groundwater (F > 1 mg/L) was relatively enriched in heavier isotopic composition and varied from -90 to -57 per thousand and from -12.2 to -6.7 per thousand for delta2H and delta18O, respectively. High chloride concentrations and delta18O values were primarily measured in groundwater samples from the northern and southwestern portions of the study area, indicating the effect of evaporation on groundwater. The observation of relatively homogenized and low delta18O values and chloride concentrations in groundwater samples from central part of the Datong Basin might be a result of fast recharge by irrigation returns, which suggests that irrigation using arsenic-contaminated groundwater affected the occurrence of high arsenic-containing groundwater in the basin.

  13. Map of Arsenic concentrations in groundwater of the United States

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The map graphic image at http://water.usgs.gov/GIS/browse/arsenic_map.png illustrates arsenic values, in micrograms per liter, for groundwater samples from about...

  14. Groundwater arsenic concentrations in Vietnam controlled by sediment age

    DEFF Research Database (Denmark)

    Postma, Dieke; Larsen, Flemming; Thai, Nguyen Thi

    2012-01-01

    Arsenic contamination of groundwater continues to threaten the health of millions of people in southeast Asia. The oxidation of organic carbon, coupled to the reductive dissolution of arsenic-bearing iron oxides, is thought to control the release of sediment-bound arsenic into groundwater. However...... at the margin of the floodplain. The groundwater arsenic content and the reactivity of sedimentary organic carbon, determined using radiotracer measurements of the rate of methanogenesis, declined with sediment age. The sedimentary pools of both iron and arsenic also declined with the burial age...

  15. Holocene estuarine sediments as a source of arsenic in Pleistocene groundwater in suburbs of Hanoi, Vietnam

    Science.gov (United States)

    Kuroda, Keisuke; Hayashi, Takeshi; Funabiki, Ayako; Do, An Thuan; Canh, Vu Duc; Nga, Tran Thi Viet; Takizawa, Satoshi

    2017-06-01

    Groundwater pollution by arsenic is a major health threat in suburban areas of Hanoi, Vietnam. The present study evaluates the effect of the sedimentary environments of the Pleistocene and Holocene deposits, and the recharge systems, on the groundwater arsenic pollution in Hanoi suburbs distant from the Red River. At two study sites (Linh Dam and Tai Mo communes), undisturbed soil cores identified a Pleistocene confined aquifer (PCA) and Holocene unconfined aquifer (HUA) as major aquifers, and Holocene estuarine and deltaic sediments as an aquitard layer between the two aquifers. The Holocene estuarine sediments (approximately 25-40 m depth, 9.6-4.8 cal ka BP) contained notably high concentrations of arsenic and organic matter, both likely to have been accumulated by mangroves during the Holocene sea-level highstand. The pore waters in these particular sediments exhibited elevated levels of arsenic and dissolved organic carbon. Arsenic in groundwater was higher in the PCA (25-94 μg/L) than in the HUA (5.2-42 μg/L), in both the monitoring wells and neighboring household tubewells. Elevated arsenic concentration in the PCA groundwater was likely due to vertical infiltration through the arsenic-rich and organic-matter-rich overlying Holocene estuarine sediments, caused by massive groundwater abstraction from the PCA. Countermeasures to prevent arsenic pollution of the PCA groundwater may include seeking alternative water resources, reducing water consumption, and/or appropriate choice of aquifers for groundwater supply.

  16. Holocene estuarine sediments as a source of arsenic in Pleistocene groundwater in suburbs of Hanoi, Vietnam

    Science.gov (United States)

    Kuroda, Keisuke; Hayashi, Takeshi; Funabiki, Ayako; Do, An Thuan; Canh, Vu Duc; Nga, Tran Thi Viet; Takizawa, Satoshi

    2017-01-01

    Groundwater pollution by arsenic is a major health threat in suburban areas of Hanoi, Vietnam. The present study evaluates the effect of the sedimentary environments of the Pleistocene and Holocene deposits, and the recharge systems, on the groundwater arsenic pollution in Hanoi suburbs distant from the Red River. At two study sites (Linh Dam and Tai Mo communes), undisturbed soil cores identified a Pleistocene confined aquifer (PCA) and Holocene unconfined aquifer (HUA) as major aquifers, and Holocene estuarine and deltaic sediments as an aquitard layer between the two aquifers. The Holocene estuarine sediments (approximately 25-40 m depth, 9.6-4.8 cal ka uc(BP)) contained notably high concentrations of arsenic and organic matter, both likely to have been accumulated by mangroves during the Holocene sea-level highstand. The pore waters in these particular sediments exhibited elevated levels of arsenic and dissolved organic carbon. Arsenic in groundwater was higher in the PCA (25-94 μg/L) than in the HUA (5.2-42 μg/L), in both the monitoring wells and neighboring household tubewells. Elevated arsenic concentration in the PCA groundwater was likely due to vertical infiltration through the arsenic-rich and organic-matter-rich overlying Holocene estuarine sediments, caused by massive groundwater abstraction from the PCA. Countermeasures to prevent arsenic pollution of the PCA groundwater may include seeking alternative water resources, reducing water consumption, and/or appropriate choice of aquifers for groundwater supply.

  17. Evaluation of deep groundwater development for arsenic mitigation in western Bangladesh.

    Science.gov (United States)

    Shibasaki, Naoaki; Lei, Peifeng; Kamata, Akira

    2007-10-01

    Groundwater contamination by arsenic frequently occurs in western Bangladesh. Integrated hydrogeological studies were carried out by the Japan International Cooperation Agency (JICA) in the Jessore, Jhenaidah and Chuadanga districts to assess the possibility of supplying safe drinking water from deep aquifers. The subsurface geology of up to 300 m in depth was classified into 5 formations (viz. A to E formations in descending order). Thick clay facies are found in C formation in the Jessore district, however, clay facies are absent in the Jhenaidah and Chuadanga districts. The clay layer separates deep aquifers from shallow aquifers, and controls vertical groundwater flow. The results of core sample analysis showed that high arsenic contents of more than 30 ppm were found not only from shallow clay but also even from deep clay below 200 m. However, the arsenic concentrations in groundwater were generally below 0.05 mg/L in the deep aquifers. The simulation study using a vertical 2-D groundwater model indicates that deep groundwater will not be contaminated by arsenic in shallow groundwater when the piezometric heads of the deep aquifers are higher than the shallow aquifers. However, the simulation results indicate that overexploitation of the deep aquifers will cause arsenic contamination in deep aquifers due to the downward movement of contaminated shallow groundwater when no sorption takes place in the sediments. These results suggest that groundwater management and control of groundwater pumpage in deep aquifers are crucial for sustainable supply of arsenic safe deep groundwater in western Bangladesh.

  18. Flourescence Humic Substances in Arsenic Contaminated Groundwater of Bangladesh

    Directory of Open Access Journals (Sweden)

    SHAFI M. TAREQ

    2012-06-01

    Full Text Available In the past, only arsenic (As concentrations in groundwater of Bangladesh were considered as having direct effects on the epidemical degrees of different types of diseases including arsenicosis, but the results of the present investigation indicated that fluorescence humic substance (HS is also an important component of dissolved organic matter in groundwater of Bangladesh. Therefore, it is suspected that both fluorescent HS and As in groundwater may have effects on the biological toxicity. The evidence of presence of high fluorescent HS and As in groundwater of Faridpur supports the above synergistic effect. The spatial distribution of fluorescence HS and As in groundwater of Faridpur indicated that the variations may be related to local hydrogeological conditions.

  19. Recent advances in the bioremediation of arsenic-contaminated groundwater.

    Science.gov (United States)

    Zouboulis, Anastasios I; Katsoyiannis, Ioannis A

    2005-02-01

    The biological treatment of groundwater is used primarily to remove electron donors from water sources, providing (biologically) stable drinking water, which preclude bacterial regrowth during subsequent water distribution. To the electron donors belong also the dissolved metal cations of ferrous iron and manganese, which are common contaminants found in most (anaerobic) groundwater. The removal of iron and manganese is usually accomplished by the application of chemical oxidation and filtration. However, biological oxidation has recently gained increased importance and application due to the existence of certain advantages, over the conventional physicochemical treatment. The oxidation of iron and manganese is accelerated by the presence of certain indigenous bacteria, the so-called "iron and manganese oxidizing bacteria." In the present paper, selected long-term experimental results will be presented, regarding the bioremediation of natural groundwater, containing elevated concentrations of iron and arsenic. Arsenic is considered as a primary pollutant in drinking water due to its high toxicity. Therefore, its efficient removal from natural waters intended for drinking water is considered of great importance. The application of biological processes for the oxidation and removal of dissolved iron was found to be an efficient treatment technique for the simultaneous removal of arsenic, from initial concentrations between 60 and 80 microg/l to residual (effluent) arsenic concentrations lower than the limit of 10 microg/l. The paper was focused on the removal of As(III) as the most common species in anaerobic groundwater and generally is removed less efficiently than the oxidized form of As(V). To obtain information for the mechanism of As(III) removal, X-ray photoelectron spectroscopy (XPS) analyses were applied and it was found that As(III) was partially oxidized to As(V), which enabled the high arsenic removal efficiency over a treatment period of 10 months.

  20. Arsenic contamination of groundwater and prevalence of arsenical dermatosis in the Hetao plain area, Inner Mongolia, China.

    Science.gov (United States)

    Guo, X; Fujino, Y; Kaneko, S; Wu, K; Xia, Y; Yoshimura, T

    2001-06-01

    An investigation was carried out on arsenic contamination of groundwater and prevalence of arsenical dermatosis in the Hetao plain of Inner Mongolia Autonomous Region, China. Based on the screening of water samples from 96 randomly selected wells in this Region, two areas (Wuyuan and Alashan) were chosen as highly contaminated areas because arsenic in the water samples was higher than 50 microg/l. Arsenic was measured using an arsenic silver diethyl dithiocarbamate method for 326 water samples from all the wells in these areas. The results show arsenic contaminated groundwater from tubule-type wells of depths about 15-30 m was serious compared with open-type wells where depth is about 3-5 m. In the Wuyuan area, 96.2% of water samples from tubule-type wells contained arsenic above 50 microg/l and 69.3% in Alashan area; the highest value was 1354 microg/l and 1088 microg/l, respectively. In these two areas, a health survey was carried out for arsenical dermatosis. The results show the prevalence of arsenical dermatosis in the Wuyuan area was 44.8%, higher than 37.1% prevalence of arsenical dermatosis in the Alashan area. The prevalence of arsenical dermatosis was highest in the over 40-year-old age group. There was no sex difference in the prevalence. Further investigation is needed to clarify the actual situation of arsenic pollution of groundwater in Inner Mongolia, China in order to reduce the adverse health effect among residents exposed to arsenic.

  1. Groundwater arsenic and fluoride in Rajnandgaon District, Chhattisgarh, northeastern India

    Science.gov (United States)

    Patel, Khageshwar Singh; Sahu, Bharat Lal; Dahariya, Nohar Singh; Bhatia, Amarpreet; Patel, Raj Kishore; Matini, Laurent; Sracek, Ondra; Bhattacharya, Prosun

    2017-07-01

    The groundwater of Ambagarh Chouki, Rajnandgaon, India, shows elevated levels of As and F-, frequently above the WHO guidelines. In this work, the concentrations of As, F-, Na+, Mg2+, Ca2+, Cl-, SO4 2-, HCO3 -, Fe, dissolved organic carbon (DOC) and dissolved inorganic carbon (DIC) in the groundwater of Ambagarh Chouki are described. The sources of dissolved components in the groundwater are investigated using the cluster and factor analysis. Five factors have been identified and linked to processes responsible for the formation of groundwater chemistry. High concentrations of dissolved As seems to be linked to high concentrations of DOC, suggesting reductive dissolution of ferric oxyhydroxides as arsenic mobilization process. Fluoride is found in shallow depth water, presumably as a consequence of evaporation of water and removal of Ca2+ by precipitation of carbonates.

  2. Arsenite-oxidizing and arsenate-reducing bacteria associated with arsenic-rich groundwater in Taiwan

    Science.gov (United States)

    Liao, Vivian Hsiu-Chuan; Chu, Yu-Ju; Su, Yu-Chen; Hsiao, Sung-Yun; Wei, Chia-Cheng; Liu, Chen-Wuing; Liao, Chung-Min; Shen, Wei-Chiang; Chang, Fi-John

    2011-04-01

    Drinking highly arsenic-contaminated groundwater is a likely cause of blackfoot disease in Taiwan, but microorganisms that potentially control arsenic mobility in the subsurface remain unstudied. The objective of this study was to investigate the relevant arsenite-oxidizing and arsenate-reducing microbial community that exists in highly arsenic-contaminated groundwater in Taiwan. We cultured and identified arsenic-transforming bacteria, analyzed arsenic resistance and transformation, and determined the presence of genetic markers for arsenic transformation. In total, 11 arsenic-transforming bacterial strains with different colony morphologies and varying arsenic transformation abilities were isolated, including 10 facultative anaerobic arsenate-reducing bacteria and one strictly aerobic arsenite-oxidizing bacterium. All of the isolates exhibited high levels of arsenic resistance with minimum inhibitory concentrations of arsenic ranging from 2 to 200 mM. Strain AR-11 was able to rapidly oxidize arsenite to arsenate at concentrations relevant to environmental groundwater samples without the addition of any electron donors or acceptors. We provide evidence that arsenic-reduction activity may be conferred by the ars operon(s) that were not amplified by the designed primers currently in use. The 16S rRNA sequence analysis grouped the isolates into the following genera: Pseudomonas, Bacillus, Psychrobacter, Vibrio, Citrobacter, Enterobacter, and Bosea. Among these genera, we present the first report of the genus Psychrobacter being involved in arsenic reduction. Our results further support the hypothesis that bacteria capable of either oxidizing arsenite or reducing arsenate coexist and are ubiquitous in arsenic-contaminated groundwater.

  3. Arsenic and Fluoride Mobilization Mechanism in Groundwater of Indus Delta and Thar Desert, Sindh, Pakistan

    Directory of Open Access Journals (Sweden)

    VIQAR HUSAIN

    2012-06-01

    Full Text Available Indus deltaic plain consists of medium to fine grained sediments, rich in organic matter deposited during the Holocene period. Thar desert is covered with sand dunes and loess originated from transported sediments from Rann of Kutch or the Indus plain by monsoon winds or by the reworking of local alluvial deposits. Groundwater salinity and microbial pollution are common in both types of lanforms, but arsenic (AS and fluoride (F toxicity dominate in the groundwater of Indus delta and Thar desert, respectively. Arsenic concentration in Tando Mohammad Khan and Tando Allayar varies from 10-500 ppb and exhibits near neutral slightly alkaline pH ranging from 6.8 to 8.0. Arsenic distribution is patchy and seems to be related to the prsence of small scale redox zonation in the aquifer. High arsenic affected areas are densely populated and intensively cultivated and its hot spots are those from where the Indus river passed during the Holocene period including Tando Allayar and Tando Mohammad Khan. Extensive ground water irrigation has accelerated flow of groundwater that brought dissolved degraded organic matter in contact with arsenic bearing sediments, enhancing reduction processes and triggering release of arsenic from detrital bioitite and muscovite in the groundwater. Furthermore, unlined sanitation and microbial contamination contribute to degradation of organic matter that enhances the reduction of iron oxy-hydroxide leading to release of arsenic to groundwater. Fluoride is found in all the groundwater samples of Tharparkar district, in the range of 0.96-2.74mg/l. The pH of groundwater is alkaline (7.38-8.59, which is accelerating maximum (1.24%F dissolution in the groundwater. The favourable pH of groundwater and soil composition of Holocene sediments of Indus delta and slightly older alluvium of Thar desert, respectively are responsible for mobilization of arsenic and fluoride in groundwater of Sindh province of Pakistan.

  4. Occurrence of arsenic in core sediments and groundwater in the Chapai-Nawabganj District, northwestern Bangladesh.

    Science.gov (United States)

    Selim Reza, A H M; Jean, Jiin-Shuh; Yang, Huai-Jen; Lee, Ming-Kuo; Woodall, Brian; Liu, Chia-Chuan; Lee, Jyh-Fu; Luo, Shang-De

    2010-03-01

    Groundwater and core sediments of two boreholes (to a depth of 50m) from the Chapai-Nawabganj area in northwestern Bangladesh were collected for arsenic concentration and geochemical analysis. Groundwater arsenic concentrations in the uppermost aquifer (10-40m of depth) range from 2.8microgL(-1) to 462.3microgL(-1). Groundwater geochemical conditions change from oxidized to successively more reduced, higher As concentration with depth. Higher sediment arsenic levels (55mgkg(-1)) were found within the upper 40m of the drilled core samples. X-ray absorption near-edge structure spectroscopy was employed to elucidate the arsenic speciation of sediments collected from two boreholes. Environmental scanning electron microscopy and transmission X-ray microscopy were used to investigate the characteristics of FeOOH in sediments which adsorb arsenic. In addition, a pH-Eh diagram was drawn using the Geochemist's Workbench (GWB) software to elucidate the arsenic speciation in groundwater. The dominant groundwater type is Ca-HCO(3) with high concentrations of As, Fe and Mn but low levels of NO(3)(-) and SO(4)(2-). Sequential extraction analysis reveals that Mn and Fe hydroxides and organic matter are the major leachable solids carrying As. High levels of arsenic concentration in aquifers are associated with fine-grained sediments. Fluorescent intensities of humic substances indicate that both groundwater and sediments in this arsenic hotspot area contain less organic matter compared to other parts of Bengal basin. Statistical analysis clearly shows that As is closely associated with Fe and Mn in sediments while As is better correlated with Mn in groundwater. These correlations along with results of sequential leaching experiments suggest that reductive dissolution of MnOOH and FeOOH mediated by anaerobic bacteria represents an important mechanism for releasing arsenic into the groundwater.

  5. High levels of inorganic arsenic in rice in areas where arsenic-contaminated water is used for irrigation and cooking

    OpenAIRE

    Rahman, M. Azizur; Hasegawa, Hiroshi

    2011-01-01

    Rice is the staple food for the people of arsenic endemic South (S) and South-East (SE) Asian countries. In this region, arsenic contaminated groundwater has been used not only for drinking and cooking purposes but also for rice cultivation during dry season. Irrigation of arsenic-contaminated groundwater for rice cultivation has resulted high deposition of arsenic in topsoil and uptake in rice grain posing a serious threat to the sustainable agriculture in this region. In addition, cooking r...

  6. Arsenic species and chemistry in groundwater of southeast Michigan

    Science.gov (United States)

    Kim, M.-J.; Nriagu, J.; Haack, S.

    2002-01-01

    Groundwater samples, taken from 73 wells in 10 counties of southeast Michigan in 1997 had arsenic concentrations in the range of 0.5 to 278 ??g/l, the average being 29 ??g/l. About 12% of these wells had arsenic concentrations that exceeded the current USEPA's maximum contaminant level of 50 ??g/l. Most (53-98%) of the arsenic detected was arsenite [As(III)] and other observations supported the arsenic species distribution (low redox potential and DO). In shallow groundwater (15 m), the concentration of arsenic is possibly controlled by reductive dissolution of arsenic-rich iron hydroxide/oxyhydroxide and dissolution of arsenic sulfide minerals. ?? 2002 Elsevier Science Ltd. All rights reserved.

  7. Groundwater arsenic contamination in Bangladesh-21 Years of research.

    Science.gov (United States)

    Chakraborti, Dipankar; Rahman, Mohammad Mahmudur; Mukherjee, Amitava; Alauddin, Mohammad; Hassan, Manzurul; Dutta, Rathindra Nath; Pati, Shymapada; Mukherjee, Subhash Chandra; Roy, Shibtosh; Quamruzzman, Quazi; Rahman, Mahmuder; Morshed, Salim; Islam, Tanzima; Sorif, Shaharir; Selim, Md; Islam, Md Razaul; Hossain, Md Monower

    2015-01-01

    Department of Public Health Engineering (DPHE), Bangladesh first identified their groundwater arsenic contamination in 1993. But before the international arsenic conference in Dhaka in February 1998, the problem was not widely accepted. Even in the international arsenic conference in West-Bengal, India in February, 1995, representatives of international agencies in Bangladesh and Bangladesh government attended the conference but they denied the groundwater arsenic contamination in Bangladesh. School of Environmental Studies (SOES), Jadavpur University, Kolkata, India first identified arsenic patient in Bangladesh in 1992 and informed WHO, UNICEF of Bangladesh and Govt. of Bangladesh from April 1994 to August 1995. British Geological Survey (BGS) dug hand tube-wells in Bangladesh in 1980s and early 1990s but they did not test the water for arsenic. Again BGS came back to Bangladesh in 1992 to assess the quality of the water of the tube-wells they installed but they still did not test for arsenic when groundwater arsenic contamination and its health effects in West Bengal in Bengal delta was already published in WHO Bulletin in 1988. From December 1996, SOES in collaboration with Dhaka Community Hospital (DCH), Bangladesh started analyzing hand tube-wells for arsenic from all 64 districts in four geomorphologic regions of Bangladesh. So far over 54,000 tube-well water samples had been analyzed by flow injection hydride generation atomic absorption spectrometry (FI-HG-AAS). From SOES water analysis data at present we could assess status of arsenic groundwater contamination in four geo-morphological regions of Bangladesh and location of possible arsenic safe groundwater. SOES and DCH also made some preliminary work with their medical team to identify patients suffering from arsenic related diseases. SOES further analyzed few thousands biological samples (hair, nail, urine and skin scales) and foodstuffs for arsenic to know arsenic body burden and people sub

  8. Assessing the Groundwater Concentrations and Geographical Distribution of Arsenic in Nepal

    Science.gov (United States)

    Ma, J.; Liu, F.

    2015-12-01

    Arsenic 33As, one of the major groundwater contaminants, occurs in both natural and anthropogenic forms. Arsenic inhibits cellular respiration and the production of ATP in human body. Prolonged intake of non-lethal quantities of arsenic can cause cancer and diseases in vital organs such as the heart, liver, skin, and kidney. Each year, millions of people in the rural areas of Bangladesh, India, and other developing countries in South Asia are exposed to arsenic-poisoned groundwater. According to the World Health Organization, arsenic levels in drinking water should not exceed 10 parts per billion; however, the levels of arsenic found in groundwater in the heavily contaminated regions are often more than ten times of the recommended limit. Nepal is one of these regions. In most of the rural areas in Nepal, there is no infrastructure to produce clean filtered water, and wells thus became the major source. However, most of these wells were dug without testing for groundwater safety, because the test commands resources that the rural communities do not have access to. This is also limited data published on Nepal's groundwater contaminant levels. The scarcity of information prohibits the international community from recognizing the severity of arsenic poisoning in Nepal and coming up with the most efficient measures to help. With this project, we will present a method to determine groundwater safety by analyzing geologic data and using remote sensing. The original source of arsenic is the arsenic-bearing minerals in the sediments. Some geological formations have higher arsenic levels than others due to their depositional environments. Therefore, by using existing geologic data from Nepal and countries with similar types of arsenic contamination, we hope to determine correlations between areas where there are reports of high concentrations of arsenic in groundwater to the environmental factors that may cause a particular concentration of arsenic. Furthermore, with deeper

  9. Spatial modeling for groundwater arsenic levels in North Carolina.

    Science.gov (United States)

    Kim, Dohyeong; Miranda, Marie Lynn; Tootoo, Joshua; Bradley, Phil; Gelfand, Alan E

    2011-06-01

    To examine environmental and geologic determinants of arsenic in groundwater, detailed geologic data were integrated with well water arsenic concentration data and well construction data for 471 private wells in Orange County, NC, via a geographic information system. For the statistical analysis, the geologic units were simplified into four generalized categories based on rock type and interpreted mode of deposition/emplacement. The geologic transitions from rocks of a primary pyroclastic origin to rocks of volcaniclastic sedimentary origin were designated as polylines. The data were fitted to a left-censored regression model to identify key determinants of arsenic levels in groundwater. A Bayesian spatial random effects model was then developed to capture any spatial patterns in groundwater arsenic residuals into model estimation. Statistical model results indicate (1) wells close to a transition zone or fault are more likely to contain detectible arsenic; (2) welded tuffs and hydrothermal quartz bodies are associated with relatively higher groundwater arsenic concentrations and even higher for those proximal to a pluton; and (3) wells of greater depth are more likely to contain elevated arsenic. This modeling effort informs policy intervention by creating three-dimensional maps of predicted arsenic levels in groundwater for any location and depth in the area.

  10. High arsenic (As concentrations in the shallow groundwaters of southern Louisiana: Evidence of microbial controls on As mobilization from sediments

    Directory of Open Access Journals (Sweden)

    Ningfang Yang

    2016-03-01

    New hydrological insights for the region: Shallow groundwaters in southern Louisiana have been reported to contain elevated As concentrations, whereas mechanisms responsible for As release from sediments have rarely been studied in this region. Microbial respiration is generally considered the main mechanism controlling As release in reducing anoxic aquifers such as the shallow aquifers in southern Louisiana and those of the Bengal basin. This study investigates the role microbial respiration plays in As release from shallow aquifer sediments in southern Louisiana through sediment incubation experiments and porewater analysis. Arsenic concentrations were the lowest in the sterilized control experiments, slightly higher in the un-amended experiments, and the highest in the experiments amended with acetate, and especially those amended with both acetate and AQDS (9,10-anthraquinone-2,6-disulfonic acid. Although Fe and Mn generally decreased at the beginning of all the experiments, they did follow a similar trend to As after the decrease. Porewater analysis showed that As and Fe concentrations were generally positively correlated and were higher in the coarse-grained sediments than in the fine-grained sediments. Results of the investigation are consistent with microbial respiration playing a key role in As release from the shallow aquifers sediments in southern Louisiana.

  11. Geochemical occurrences of arsenic and fluoride in bedrock groundwater: a case study in Geumsan County, Korea.

    Science.gov (United States)

    Ahn, Joo Sung

    2012-01-01

    Bedrock groundwaters in Geumsan County, Korea, were surveyed to investigate the distribution and geochemical behaviors of arsenic and fluoride, mobilized through geogenic processes. The concentrations were enriched up to 113 μg/L for arsenic and 7.54 mg/L for fluoride, and 16% of 150 samples exceeded World Health Organization drinking water guidelines for each element. Simple Ca-HCO(3) groundwater types and positive correlations with pH, Ca, SO(4), and HCO(3) were characteristics of high (>10 μg/L) As groundwaters. The oxidation reaction of sulfide minerals in metasedimentary rocks and locally mineralized zones seems to be ultimately responsible for the existence of arsenic in groundwater. Desorption process under high pH conditions may also control the arsenic mobility in the study area. High (>1.5 mg/L) F groundwaters were found in the Na-HCO(3) type and with greater depth. Fluoride seemed to be enriched by deep groundwater interaction with granitic rocks, and continuous supply to shallow Ca-HCO(3)-type groundwater kept the concentration high. In the study area, drinking water management should include periodic As and F monitoring in groundwater.

  12. Arsenic Contamination of Groundwater in Nepal—An Overview

    Directory of Open Access Journals (Sweden)

    Sudhir Kumar Singh

    2010-12-01

    Full Text Available In Nepal, arsenic (As contamination is a major issue of current drinking water supply systems using groundwater and has recently been one of the major environmental health management issues especially in the plain region, i.e., in the Terai districts, where the population density is very high. The Terai inhabitants still use hand tube and dug wells (with hand held pumps that are bored at shallow to medium depth for their daily water requirements, including drinking water. The National Sanitation Steering Committee (NSSC, with the help of many other organizations, has completed arsenic blanket test in 25 districts of Nepal by analysing 737,009 groundwater samples. Several organizations, including academic institutions, made an effort to determine the levels of arsenic concentrations in groundwater and their consequences in Nepal. The results of the analyses on 25,058 samples tested in 20 districts, published in the status report of arsenic in Nepal (2003, demonstrated that the 23% of the samples were containing 10–50 µg/L of As, and the 8% of the samples were containing more than 50 µg/L of As. Recent status of over 737,009 samples tested, the 7.9% and 2.3% were contaminated by 10–50 µg/L and >50 µg/L, respectively of As. The present paper examines the various techniques available for the reduction of arsenic concentrations in Nepal in combination with the main results achieved, the socio-economic status and the strategies. This paper aims to comprehensively compile all existing data sets and analyze them scientifically, by trying to suggest a common sustainable approach for identifying the As contamination in the nation, that can be easily adopted by local communities for developing a sustainable society. The paper aims also to find probable solutions to quantify and mitigate As problem without any external support. The outcome of this paper will ultimately help to identify various ways for: identify risk areas; develop awareness; adopt

  13. Pathways for arsenic from sediments to groundwater to streams: Biogeochemical processes in the Inner Coastal Plain, New Jersey, USA

    Science.gov (United States)

    Barringer, Julia L.; Mumford, Adam; Young, Lily Y.; Reilly, Pamela A.; Bonin, Jennifer L.; Rosman, Robert

    2010-01-01

    The Cretaceous and Tertiary sediments that underlie the Inner Coastal Plain of New Jersey contain the arsenic-rich mineral glauconite. Streambed sediments in two Inner Coastal Plain streams (Crosswicks and Raccoon Creeks) that traverse these glauconitic deposits are enriched in arsenic (15–25 mg/kg), and groundwater discharging to the streams contains elevated levels of arsenic (>80 μg/L at a site on Crosswicks Creek) with arsenite generally the dominant species. Low dissolved oxygen, low or undetectable levels of nitrate and sulfate, detectable sulfide concentrations, and high concentrations of iron and dissolved organic carbon (DOC) in the groundwater indicate that reducing environments are present beneath the streambeds and that microbial activity, fueled by the DOC, is involved in releasing arsenic and iron from the geologic materials. In groundwater with the highest arsenic concentrations at Crosswicks Creek, arsenic respiratory reductase gene (arrA) indicated the presence of arsenic-reducing microbes. From extracted DNA, 16s rRNA gene sequences indicate the microbial community may include arsenic-reducing bacteria that have not yet been described. Once in the stream, iron is oxidized and precipitates as hydroxide coatings on the sediments. Arsenite also is oxidized and co-precipitates with or is sorbed to the iron hydroxides. Consequently, dissolved arsenic concentrations are lower in streamwater than in the groundwater, but the arsenic contributed by groundwater becomes part of the arsenic load in the stream when sediments are suspended during high flow. A strong positive relation between concentrations of arsenic and DOC in the groundwater samples indicates that any process—natural or anthropogenic—that increases the organic carbon concentration in the groundwater could stimulate microbial activity and thus increase the amount of arsenic that is released from the geologic materials.

  14. River bank geomorphology controls groundwater arsenic concentrations in aquifers adjacent to the Red River, Hanoi Vietnam

    Science.gov (United States)

    Stahl, Mason O.; Harvey, Charles F.; van Geen, Alexander; Sun, Jing; Thi Kim Trang, Pham; Mai Lan, Vi; Mai Phuong, Thao; Hung Viet, Pham; Bostick, Benjamin C.

    2016-08-01

    Many aquifers that are highly contaminated by arsenic in South and Southeast Asia are in the floodplains of large river networks. Under natural conditions, these aquifers would discharge into nearby rivers; however, large-scale groundwater pumping has reversed the flow in some areas so that rivers now recharge aquifers. At a field site near Hanoi Vietnam, we find river water recharging the aquifer becomes high in arsenic, reaching concentrations above 1000 µg/L, within the upper meter of recently (50 µg/L) aqueous arsenic concentrations are found in aquifer regions adjacent to zones where the river has recently deposited sediment and low arsenic concentrations are found in aquifer regions adjacent to erosional zones. High arsenic concentrations are even found adjacent to a depositional river reach in a Pleistocene aquifer, a type of aquifer sediment which generally hosts low arsenic water. Using geochemical and isotopic data, we estimate the in situ rate of arsenic release from riverbed sediments to be up to 1000 times the rates calculated on inland aquifer sediments in Vietnam. Geochemical data for riverbed porewater conditions indicate that the reduction of reactive, poorly crystalline iron oxides controls arsenic release. We suggest that aquifers in these regions may be susceptible to further arsenic contamination where riverine recharge drawn into aquifers by extensive groundwater pumping flows through recently deposited river sediments before entering the aquifer.

  15. Both Phosphorus Fertilizers and Indigenous Bacteria Enhance Arsenic Release into Groundwater in Arsenic-Contaminated Aquifers.

    Science.gov (United States)

    Lin, Tzu-Yu; Wei, Chia-Cheng; Huang, Chi-Wei; Chang, Chun-Han; Hsu, Fu-Lan; Liao, Vivian Hsiu-Chuan

    2016-03-23

    Arsenic (As) is a human carcinogen, and arsenic contamination in groundwater is a worldwide public health concern. Arsenic-affected areas are found in many places but are reported mostly in agricultural farmlands, yet the interaction of fertilizers, microorganisms, and arsenic mobilization in arsenic-contaminated aquifers remains uncharacterized. This study investigates the effects of fertilizers and bacteria on the mobilization of arsenic in two arsenic-contaminated aquifers. We performed microcosm experiments using arsenic-contaminated sediments and amended with inorganic nitrogenous or phosphorus fertilizers for 1 and 4 months under aerobic and anaerobic conditions. The results show that microcosms amended with 100 mg/L phosphorus fertilizers (dipotassium phosphate), but not nitrogenous fertilizers (ammonium sulfate), significantly increase aqueous As(III) release in arsenic-contaminated sediments under anaerobic condition. We also show that concentrations of iron, manganese, potassium, sodium, calcium, and magnesium are increased in the aqueous phase and that the addition of dipotassium phosphate causes a further increase in aqueous iron, potassium, and sodium, suggesting that multiple metal elements may take part in the arsenic release process. Furthermore, microbial analysis indicates that the dominant microbial phylum is shifted from α-proteobacteria to β- and γ-proteobacteria when the As(III) is increased and phosphate is added in the aquifer. Our results provide evidence that both phosphorus fertilizers and microorganisms can mediate the release of arsenic to groundwater in arsenic-contaminated sediments under anaerobic condition. Our study suggests that agricultural activity such as the use of fertilizers and monitoring phosphate concentration in groundwater should be taken into consideration for the management of arsenic in groundwater.

  16. Cl/Br ratios and chlorine isotope evidences for groundwater salinization and its impact on groundwater arsenic, fluoride and iodine enrichment in the Datong basin, China

    Energy Technology Data Exchange (ETDEWEB)

    Li, Junxia; Wang, Yanxin, E-mail: yx.wang@cug.edu.cn; Xie, Xianjun

    2016-02-15

    In order to identify the salinization processes and its impact on arsenic, fluoride and iodine enrichment in groundwater, hydrogeochemical and environmental isotope studies have been conducted on groundwater from the Datong basin, China. The total dissolved solid (TDS) concentrations in groundwater ranged from 451 to 8250 mg/L, and 41% of all samples were identified as moderately saline groundwater with TDS of 3000–10,000 mg/L. The results of groundwater Cl concentrations, Cl/Br molar ratio and Cl isotope composition suggest that three processes including water-rock interaction, surface saline soil flushing, and evapotranspiration result in the groundwater salinization in the study area. The relatively higher Cl/Br molar ratio in groundwater from multiple screening wells indicates the contribution of halite dissolution from saline soil flushed by vertical infiltration to the groundwater salinization. However, the results of groundwater Cl/Br molar ratio model indicate that the effect of saline soil flushing practice is limited to account for the observed salinity variation in groundwater. The plots of groundwater Cl vs. Cl/Br molar ratio, and Cl vs δ{sup 37}Cl perform the dominant effects of evapotranspiration on groundwater salinization. Inverse geochemical modeling results show that evapotranspiration may cause approximately 66% loss of shallow groundwater to account for the observed hydrochemical pattern. Due to the redox condition fluctuation induced by irrigation activities and evapotranspiration, groundwater salinization processes have negative effects on groundwater arsenic enrichment. For groundwater iodine and fluoride enrichment, evapotranspiration partly accounts for their elevation in slightly saline water. However, too strong evapotranspiration would restrict groundwater fluoride concentration due to the limitation of fluorite solubility. - Highlights: • Natural high arsenic, fluoride and iodine groundwater co-occur with saline water.

  17. Influence of groundwater composition on subsurface iron and arsenic removal

    KAUST Repository

    Moed, David H.

    2012-06-01

    Subsurface arsenic and iron removal (SAR/SIR) is a novel technology to remove arsenic, iron and other groundwater components by using the subsoil. This research project investigated the influence of the groundwater composition on subsurface treatment. In anoxic sand column experiments, with synthetic groundwater and virgin sand, it was found that several dissolved substances in groundwater compete for adsorption sites with arsenic and iron. The presence of 0.01 mmol L -1phosphate, 0.2 mmol L -1 silicate, and 1 mmol L -1 nitrate greatly reduced the efficiency of SAR, illustrating the vulnerability of this technology in diverse geochemical settings. SIR was not as sensitive to other inorganic groundwater compounds, though iron retardation was limited by 1.2 mmol L -1 calcium and 0.06 mmol L -1 manganese. © IWA Publishing 2012.

  18. Arsenic in groundwater of Licking County, Ohio, 2012—Occurrence and relation to hydrogeology

    Science.gov (United States)

    Thomas, Mary Ann

    2016-02-23

    Arsenic concentrations were measured in samples from 168 domestic wells in Licking County, Ohio, to document arsenic concentrations in a wide variety of wells and to identify hydrogeologic factors associated with arsenic concentrations in groundwater. Elevated concentrations of arsenic (greater than 10.0 micrograms per liter [µg/L]) were detected in 12 percent of the wells (about 1 in 8). The maximum arsenic concentration of about 44 µg/L was detected in two wells in the same township.A subset of 102 wells was also sampled for iron, sulfate, manganese, and nitrate, which were used to estimate redox conditions of the groundwater. Elevated arsenic concentrations were detected only in strongly reducing groundwater. Almost 20 percent of the samples with iron concentrations high enough to produce iron staining (greater than 300 µg/L) also had elevated concentrations of arsenic.In groundwater, arsenic primarily occurs as two inorganic species—arsenite and arsenate. Arsenic speciation was determined for a subset of nine samples, and arsenite was the predominant species. Of the two species, arsenite is more difficult to remove from water, and is generally considered to be more toxic to humans.Aquifer and well-construction characteristics were compiled from 99 well logs. Elevated concentrations of arsenic (and iron) were detected in glacial and bedrock aquifers but were more prevalent in glacial aquifers. The reason may be that the glacial deposits typically contain more organic carbon than the Paleozoic bedrock. Organic carbon plays a role in the redox reactions that cause arsenic (and iron) to be released from the aquifer matrix. Arsenic concentrations were not significantly different for different types of bedrock (sandstone, shale, sandstone/shale, or other). However, arsenic concentrations in bedrock wells were correlated with two well-construction characteristics; higher arsenic concentrations in bedrock wells were associated with (1) shorter open intervals and

  19. On the Spatial Variability of Arsenic Contamination in the Groundwater of Bangladesh

    Science.gov (United States)

    Karthik, B.; Islam, S.; Harvey, C. F.

    2001-05-01

    The widespread arsenic contamination of groundwater in Bangladesh has been recognized as posing a serious health problem to millions of people in the region. We have performed a detailed spatial analysis of arsenic data from groundwater in an attempt to identify dominant controls on the spatial distribution of arsenic. The variogram analysis suggests that large-scale geological and physical features control a significant fraction of the spatial variability in shallow wells (55 %) as well as in the deeper wells (88 %). We propose that the prevalence of higher arsenic concentrations of arsenic in shallow wells is because of the `small-scale' processes (less than 6 km. approx.) exerting a greater degree of control at shallower depths in the sediments. A comparison of the correlated spatial variability for high and low arsenic concentrations indicates that the `large scale' processes also control the distribution of higher arsenic concentrations to a significant extent. Through an indicator variogram analysis we demonstrate that the correlation structure of the arsenic magnitudes is primarily due to the spatial distribution of their locations, around an approximate concentration cut-off limit of 0.07 mg/L. Our results suggest that the complex spatial distribution of high-level arsenic concentrations is a consequence of interactions among multiscale geologic and geochemical processes.

  20. Evaluation of the fate of arsenic-contaminated groundwater at different aquifers of Thar coalfield Pakistan.

    Science.gov (United States)

    Ali, Jamshed; Kazi, Tasneem G; Baig, Jameel A; Afridi, Hassan I; Arain, Mariam S; Ullah, Naeem; Brahman, Kapil D; Arain, Sadaf S; Panhwar, Abdul H

    2015-12-01

    In present study, the ground water at different aquifers was evaluated for physicochemical parameters, iron, total arsenic, total inorganic arsenic and arsenic species (arsenite and arsenate). The samples of groundwater were collected at different depths, first aquifer (AQ1) 50-60 m, second aquifer (AQ2) 100-120 m, and third aquifer (AQ3) 200-250 m of Thar coalfield, Pakistan. Total inorganic arsenic was determined by solid phase extraction using titanium dioxide as an adsorbent. The arsenite was determined by cloud point extraction using ammonium pyrrolidinedithiocarbamate as a chelating reagent, and resulted complex was extracted by Triton X-114. The resulted data of groundwater were reported in terms of basic statistical parameters, principal component, and cluster analysis. The resulted data indicated that physicochemical parameters of groundwater of different aquifers were exceeded the World Health Organization provisional guideline for drinking water except pH and SO4(2-). The positive correlation was observed between arsenic species and physicochemical parameters of groundwater except F(-) and K(+), which might be caused by geochemical minerals. Results of cluster analysis indicated that groundwater samples of AQ1 was highly contaminated with arsenic species as compared to AQ2 and AQ3 (p > 0.05).

  1. Evaluation of the sustainability of deep groundwater as an arsenic-safe resource in the Bengal Basin

    Science.gov (United States)

    Michaela, Holly A.; Voss, Clifford I.

    2008-01-01

    Tens of millions of people in the Bengal Basin region of Bangladesh and India drink groundwater containing unsafe concentrations of arsenic. This high-arsenic groundwater is produced from shallow (150 m where groundwater arsenic concentrations are nearly uniformly low, and many more wells are needed, however, the sustainability of deep, arsenic-safe groundwater has not been previously assessed. Deeper pumping could induce downward migration of dissolved arsenic, permanently destroying the deep resource. Here, it is shown, through quantitative, large-scale hydrogeologic analysis and simulation of the entire basin, that the deeper part of the aquifer system may provide a sustainable source of arsenic-safe water if its utilization is limited to domestic supply. Simulations provide two explanations for this result: deep domestic pumping only slightly perturbs the deep groundwater flow system, and substantial shallow pumping for irrigation forms a hydraulic barrier that protects deeper resources from shallow arsenic sources. Additional analysis indicates that this simple management approach could provide arsenic-safe drinking water to >90% of the arsenic-impacted region over a 1,000-year timescale. This insight may assist water-resources managers in alleviating one of the world's largest groundwater contamination problems.

  2. Evaluation of the sustainability of deep groundwater as an arsenic-safe resource in the Bengal Basin

    Science.gov (United States)

    Michael, H.A.; Voss, C.I.

    2008-01-01

    Tens of millions of people in the Bengal Basin region of Bangladesh and India drink groundwater containing unsafe concentrations of arsenic. This high-arsenic groundwater is produced from shallow (150 m where groundwater arsenic concentrations are nearly uniformly low, and many more wells are needed, however, the sustainability of deep, arsenic-safe ground-water has not been previously assessed. Deeper pumping could induce downward migration of dissolved arsenic, permanently destroying the deep resource. Here, it is shown, through quantitative, large-scale hydrogeologic analysis and simulation of the entire basin, that the deeper part of the aquifer system may provide a sustainable source of arsenic-safe water if its utilization is limited to domestic supply. Simulations provide two explanations for this result: deep domestic pumping only slightly perturbs the deep groundwater flow system, and substantial shallow pumping for irrigation forms a hydraulic barrier that protects deeper resources from shallow arsenic sources. Additional analysis indicates that this simple management approach could provide arsenic-safe drinking water to >90% of the arsenic-impacted region over a 1,000-year timescale. This insight may assist water-resources managers in alleviating one of the world's largest groundwater contamination problems. ?? 2008 by The National Academy of Sciences of the USA.

  3. A generalized regression model of arsenic variations in the shallow groundwater of Bangladesh

    OpenAIRE

    Shamsudduha, M.; Taylor, R. G.; Chandler, R. E.

    2015-01-01

    Abstract Localized studies of arsenic (As) in Bangladesh have reached disparate conclusions regarding the impact of irrigation‐induced recharge on As concentrations in shallow (≤50 m below ground level) groundwater. We construct generalized regression models (GRMs) to describe observed spatial variations in As concentrations in shallow groundwater both (i) nationally, and (ii) regionally within Holocene deposits where As concentrations in groundwater are generally high (>10 μg L−1). At these ...

  4. Adsorptive removal of manganese, arsenic and iron from groundwater

    NARCIS (Netherlands)

    Buamah, R.

    2009-01-01

    To determine the scale of the problem of arsenic, iron and manganese contamination of groundwater in Ghana a survey was performed in the first phase of the research to provide in depth information with respect to these contaminants. Presence of these mentioned contaminants in groundwater is not pecu

  5. Adsorptive removal of manganese, arsenic and iron from groundwater

    NARCIS (Netherlands)

    Buamah, R.

    2009-01-01

    To determine the scale of the problem of arsenic, iron and manganese contamination of groundwater in Ghana a survey was performed in the first phase of the research to provide in depth information with respect to these contaminants. Presence of these mentioned contaminants in groundwater is not

  6. Tracing organic matter composition and distribution and its role on arsenic release in shallow Cambodian groundwaters

    Science.gov (United States)

    Lawson, Michael; Polya, David A.; Boyce, Adrian J.; Bryant, Charlotte; Ballentine, Christopher J.

    2016-04-01

    Biogeochemical processes that utilize dissolved organic carbon are widely thought to be responsible for the liberation of arsenic from sediments to shallow groundwater in south and southeast Asia. The accumulation of this known carcinogen to hazardously high concentrations has occurred in the primary source of drinking water in large parts of densely populated countries in this region. Both surface and sedimentary sources of organic matter have been suggested to contribute dissolved organic carbon in these aquifers. However, identification of the source of organic carbon responsible for driving arsenic release remains enigmatic and even controversial. Here, we provide the most extensive interrogation to date of the isotopic signature of ground and surface waters at a known arsenic hotspot in Cambodia. We present tritium and radiocarbon data that demonstrates that recharge through ponds and/or clay windows can transport young, surface derived organic matter into groundwater to depths of 44 m under natural flow conditions. Young organic matter dominates the dissolved organic carbon pool in groundwater that is in close proximity to these surface water sources and we suggest this is likely a regional relationship. In locations distal to surface water contact, dissolved organic carbon represents a mixture of both young surface and older sedimentary derived organic matter. Ground-surface water interaction therefore strongly influences the average dissolved organic carbon age and how this is distributed spatially across the field site. Arsenic mobilization rates appear to be controlled by the age of dissolved organic matter present in these groundwaters. Arsenic concentrations in shallow groundwaters (20 m) groundwaters. We suggest that, while the rate of arsenic release is greatest in shallow aquifer sediments, arsenic release also occurs in deeper aquifer sediments and as such remains an important process in controlling the spatial distribution of arsenic in the

  7. Arsenic in groundwaters in the Northern Appalachian Mountain belt: a review of patterns and processes.

    Science.gov (United States)

    Peters, Stephen C

    2008-07-29

    Naturally occurring arsenic in the bedrock of the Northern Appalachian Mountain belt was first recognized in the late 19th century. The knowledge of the behavior of arsenic in groundwater in this region has lagged behind nearly a century, with the popular press reporting on local studies in the early 1980s, and most peer-reviewed research articles on regional patterns conducted and written in the late 1990s and early 2000s. Research reports have shown that within this high arsenic region, between 6% and 22% of households using private drinking water wells contain arsenic in excess of 10 microg/L, the United States Environmental Protection Agency's maximum contaminant level. In nearly all reports, arsenic in drinking water was derived from naturally occurring geologic sources, typically arsenopyrite, substituted sulfides such as arsenian pyrite, and nanoscale minerals such as westerveldite. In most studies, arsenic concentrations in groundwater were controlled by pH dependent adsorption to mineral surfaces, most commonly iron oxide minerals. In some cases, reductive dissolution of iron minerals has been shown to increase arsenic concentrations in groundwater, more commonly associated with anthropogenic activities such as landfills. Evidence of nitrate reduction promoting the presence of arsenic(V) and iron(III) minerals in anoxic environments has been shown to occur in surface waters, and in this manuscript we show this process perhaps applies to groundwater. The geologic explanation for the high arsenic region in the Northern Appalachian Mountain belt is most likely the crustal recycling of arsenic as an incompatible element during tectonic activity. Accretion of multiple terranes, in particular Avalonia and the Central Maine Terrane of New England appear to be connected to the presence of high concentrations of arsenic. Continued tectonic activity and recycling of these older terranes may also be responsible for the high arsenic observed in the Triassic rift

  8. Arsenic in Bangladesh Groundwater: Where it Comes From and why

    Science.gov (United States)

    Zheng, Y.; van Geen, A.; Stute, M.; Dhar, R.; Mo, Z.; Cheng, Z.; Horneman, A.; Simpson, H. J.; Gavrieli, I.; Ahmed, K. M.

    2002-12-01

    Arsenic (As) is a highly toxic, ubiquitous metalloid and realization is growing that water-borne As now poses a significant threat to human and ecosystem health worldwide. Elevated concentrations of As in groundwater have emerged as a major health threat in the Ganges-Brahmaputra Delta region where tens of millions of people are exposed to [As] 10 to 100 times higher than the drinking water standard of 10 μg/L recommended by the WHO. Extensive sampling by the British Geological Survey has shown that water from shallow aquifers with recent alluvial sediments carries distinctly higher [As] than does water from deeper aquifers with presumed pre-Holocene sediments. However, the reasons why such a large contrast in [As] exists between younger, Holocene aquifers and older, Pleistocene aquifers are not well understood. Furthermore, although As is generally believed to be of natural origin and is mobilized in reducing groundwater, the sources of particle phase As and mechanisms of arsenic release to groundwater remain poorly understood. Hydrological and geochemical factors contributing to elevated arsenic concentrations (up to 800 μg/L) in the shallow aquifers and much lower [As](Bangladesh. Araihazar is on the margin of the Holocene Mehgna fluvial floodplain where the transition occurs from the uplifted mid Pleistocene Madhupur tract to much younger, incised Meghna river channel deposits from west to east. Coring confirmed that the aquifers were separated by a multiple-layered silt/clay section. At least at one site, radiocarbon dating of peat layers within the silt/clay section suggests that a Holocene aquifer is unconformably overlying a Pleistocene sequence. Based on radiocarbon and tritium dating, the residence time of groundwater in the high-As shallow, Holocene aquifers (4 - 30 m) is years to decades, much less than that of the low-As deep aquifer (50- 100 m), which is a thousand to tens of thousands of years. This hydrological separation is important in

  9. In situ treatment of arsenic contaminated groundwater by aquifer iron coating: Experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Xianjun, E-mail: xjxie@cug.edu.cn [State Key Laboratory of Biogeology and Environmental Geology, School of Environmental Studies, China University of Geosciences, 430074 Wuhan (China); Wang, Yanxin, E-mail: yx.wang@cug.edu.cn [State Key Laboratory of Biogeology and Environmental Geology, School of Environmental Studies, China University of Geosciences, 430074 Wuhan (China); Pi, Kunfu [State Key Laboratory of Biogeology and Environmental Geology, School of Environmental Studies, China University of Geosciences, 430074 Wuhan (China); Liu, Chongxuan [State Key Laboratory of Biogeology and Environmental Geology, School of Environmental Studies, China University of Geosciences, 430074 Wuhan (China); Pacific Northwest National Laboratory, Richland, WA 99354 (United States); Li, Junxia; Liu, Yaqing; Wang, Zhiqiang; Duan, Mengyu [State Key Laboratory of Biogeology and Environmental Geology, School of Environmental Studies, China University of Geosciences, 430074 Wuhan (China)

    2015-09-15

    In situ arsenic removal from groundwater by an aquifer iron coating method has great potential to be a cost effective and simple groundwater remediation technology, especially in rural and remote areas where groundwater is used as the main water source for drinking. The in situ arsenic removal technology was first optimized by simulating arsenic removal in various quartz sand columns under anoxic conditions. The effectiveness was then evaluated in an actual high-arsenic groundwater environment. The arsenic removal mechanism by the coated iron oxide/hydroxide was investigated under different conditions using scanning electron microscopy (SEM)/X-ray absorption spectroscopy, electron probe microanalysis, and Fourier transformation infrared spectroscopy. Aquifer iron coating method was developed via a 4-step alternating injection of oxidant, iron salt and oxygen-free water. A continuous injection of 5.0 mmol/L FeSO{sub 4} and 2.5 mmol/L NaClO for 96 h can form a uniform goethite coating on the surface of quartz sand without causing clogging. At a flow rate of 7.2 mL/min of the injection reagents, arsenic (as Na{sub 2}HAsO{sub 4}) and tracer fluorescein sodium to pass through the iron-coated quartz sand column were approximately at 126 and 7 column pore volumes, respectively. The retardation factor of arsenic was 23.0, and the adsorption capacity was 0.11 mol As per mol Fe. In situ arsenic removal from groundwater in an aquifer was achieved by simultaneous injections of As(V) and Fe(II) reagents. Arsenic fixation resulted from a process of adsorption/co-precipitation with fine goethite particles by way of bidentate binuclear complexes. Therefore, the study results indicate that the high arsenic removal efficiency of the in situ aquifer iron coating technology likely resulted from the expanded specific surface area of the small goethite particles, which enhanced arsenic sorption capability and/or from co-precipitation of arsenic on the surface of goethite particles

  10. Impact of irrigation with high arsenic burdened groundwater on the soil-plant system: Results from a case study in the Inner Mongolia, China.

    Science.gov (United States)

    Neidhardt, H; Norra, S; Tang, X; Guo, H; Stüben, D

    2012-04-01

    Consequences of irrigation by arsenic (As) enriched groundwater were assigned in the Hetao Plain, part of Chinas' Inner Mongolia Autonomous Region. Examinations followed the As flow path from groundwater to soil and finally plants. A sunflower and a maize field were systematically sampled, each irrigated since three years with saline well water, characterized by elevated As concentrations (154 and 238μgL(-1)). The annual As input per m(2) was estimated as 120 and 186mg, respectively. Compared to the geogenic background, As concentrations increased toward the surface with observed enrichments in topsoil being relatively moderate (up to 21.1mgkg(-1)). Arsenic concentrations in plant parts decreased from roots toward leaves, stems and seeds. It is shown that the bioavailability of As is influenced by a complex interplay of partly counteracting processes. To prevent As enrichment and soil salinization, local farmers were recommended to switch to a less problematic water source.

  11. Toxicological and chemical assessment of arsenic-contaminated groundwater after electrochemical and advanced oxidation treatments.

    Science.gov (United States)

    Radić, Sandra; Crnojević, Helena; Vujčić, Valerija; Gajski, Goran; Gerić, Marko; Cvetković, Želimira; Petra, Cvjetko; Garaj-Vrhovac, Vera; Oreščanin, Višnja

    2016-02-01

    Owing to its proven toxicity and mutagenicity, arsenic is regarded a principal pollutant in water used for drinking. The objective of this study was the toxicological and chemical evaluation of groundwater samples obtained from arsenic enriched drinking water wells before and after electrochemical and ozone-UV-H2O2-based advanced oxidation processes (EAOP). For this purpose, acute toxicity test with Daphnia magna and chronic toxicity test with Lemna minor L. were employed as well as in vitro bioassays using human peripheral blood lymphocytes (HPBLs). Several oxidative stress parameters were estimated in L.minor. Physicochemical analysis showed that EAOP treatment was highly efficient in arsenic but also in ammonia and organic compound removal from contaminated groundwater. Untreated groundwater caused only slight toxicity to HPBLs and D. magna in acute experiments. However, 7-day exposure of L. minor to raw groundwater elicited genotoxicity, a significant growth inhibition and oxidative stress injury. The observed genotoxicity and toxicity of raw groundwater samples was almost completely eliminated by EAOP treatment. Generally, the results obtained with L. minor were in agreement with those obtained in the chemical analysis suggesting the sensitivity of the model organism in monitoring of arsenic-contaminated groundwater. In parallel to chemical analysis, the implementation of chronic toxicity bioassays in a battery is recommended in the assessment of the toxic and genotoxic potential of such complex mixtures.

  12. Arsenic in the groundwater: Occurrence, toxicological activities, and remedies.

    Science.gov (United States)

    Jha, S K; Mishra, V K; Damodaran, T; Sharma, D K; Kumar, Parveen

    2017-04-03

    Arsenic (As) contamination in groundwater has become a geo-environmental as well as a toxicological problem across the globe affecting more than 100-million people in nearly 21 countries with its associated disease "arsenicosis." Arsenic poisoning may lead to fatal skin and internal cancers. In present review, an attempt has been made to generate awareness among the readers about various sources of occurrence of arsenic, its geochemistry and speciation, mobilization, metabolism, genotoxicity, and toxicological exposure on humans. The article also emphasizes the possible remedies for combating the problem. The knowledge of these facts may help to work on some workable remedial measure.

  13. Speciation analysis of arsenic in groundwater from Inner Mongolia with an emphasis on acid-leachable particulate arsenic

    Energy Technology Data Exchange (ETDEWEB)

    Gong Zhilong [Department of Public Health Sciences, University of Alberta, 10-102 Clinical Sciences Building, Edmonton, Alta., T6G 2G3 (Canada); Lu Xiufen [Department of Public Health Sciences, University of Alberta, 10-102 Clinical Sciences Building, Edmonton, Alta., T6G 2G3 (Canada); Watt, Corinna [Department of Public Health Sciences, University of Alberta, 10-102 Clinical Sciences Building, Edmonton, Alta., T6G 2G3 (Canada); Wen Bei [Department of Public Health Sciences, University of Alberta, 10-102 Clinical Sciences Building, Edmonton, Alta., T6G 2G3 (Canada); He Bin [Department of Public Health Sciences, University of Alberta, 10-102 Clinical Sciences Building, Edmonton, Alta., T6G 2G3 (Canada); Mumford, Judy [National Health and Environmental Effects Research Laboratory, Environmental Protection Agency, Human Studies Division, Epidemiology and Biomarkers Branch, Research Triangle Park, NC 27711 (United States); Ning Zhixiong [Ba Men Anti-Epidemic Station, Lin He, Inner Mongolia (China); Xia Yajuan [Inner Mongolia Center for Endemic Disease Control and Research, Huhhot, Inner Mongolia (China); Le, X. Chris [Department of Public Health Sciences, University of Alberta, 10-102 Clinical Sciences Building, Edmonton, Alta., T6G 2G3 (Canada)]. E-mail: xc.le@ualberta.ca

    2006-01-05

    Arsenic in drinking water affects millions of people around the world. While soluble arsenic is commonly measured, the amount of particulate arsenic in drinking water has often been overlooked. We report here determination of the acid-leachable particulate arsenic and soluble arsenicals in well water from an arsenic-poisoning endemic area in Inner Mongolia, China. Water samples (583) were collected from 120 wells in Ba Men, Inner Mongolia, where well water was the primary drinking water source. Two methods were demonstrated for the determination of soluble arsenic species (primarily inorganic arsenate and arsenite) and total particulate arsenic. The first method used solid phase extraction cartridges and membrane filters to separate arsenic species on-site, followed by analysis of the individual arsenic species eluted from the cartridges and filters. The other method uses liquid chromatography separation with hydride generation atomic fluorescence detection to determine soluble arsenic species. Analysis of acidified water samples using inductively coupled plasma mass spectrometry provided the total arsenic concentration. Arsenic concentrations in water samples from the 120 wells ranged from <1 to {approx}1000 {mu}g L{sup -1}. On average, particulate arsenic accounted for 39 {+-} 38% (median 36%) of the total arsenic. In some wells, particulate arsenic was six times higher than the soluble arsenic concentration. Particulate arsenic can be effectively removed using membrane filtration. The information on particulate and soluble arsenic in water is useful for optimizing treatment options and for understanding the geochemical behavior of arsenic in groundwater.

  14. Arsenic in groundwater of the Kolkata Municipal Corporation (KMC), India: Critical review and modes of mitigation.

    Science.gov (United States)

    Chakraborti, Dipankar; Das, Bhaskar; Rahman, Mohammad Mahmudur; Nayak, Bishwajit; Pal, Arup; Sengupta, Mrinal K; Ahamed, Sad; Hossain, Md Amir; Chowdhury, Uttam K; Biswas, Bhajan Kumar; Saha, Khitish Chandra; Dutta, R N

    2017-08-01

    This study represents the first comprehensive report of groundwater arsenic contamination status in the Kolkata Municipal Corporation (KMC). During the past 23 years, 4210 groundwater samples were analysed from all 141 wards in the KMC: 14.2% and 5.2% samples had arsenic >10 μg/l and >50 μg/l, respectively, representing 77 and 37 wards. The study shows that the number of arsenic contaminated samples (and wards) in the southern part of the KMC exceeds that of other parts of the city. The daily intake of arsenic from drinking water was estimated as 0.95 μg per kg bw and the cancer risk was estimated as 1425/10(6). Analyses of biological samples (hair, nail and urine) showed elevated concentrations of arsenic indicating the presence of subclinical arsenic poisoning, predicting an enhanced lifetime cancer risk for the population in southern part of the KMC. In the KMC, groundwater is not a sustainable source of freshwater due to arsenic, high iron, hardness and total dissolved solids. Its continued use is impelled by the lack of an adequate infrastructure to treat and supply surface water and in some wards the unaccounted for water (UFW) is even >45% incurred during distribution. The rare imposition of a water tax makes the water supply systems unsustainable and fosters indifference to water conservation. To mitigate the arsenic problem, continuous groundwater monitoring for pollutants, a treated surface water supply with strict policy implications, rainwater harvesting in the urban areas and introduction of water taxes seem to be long-term visible solutions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Uptake of Arsenic in Rice Plant Varieties Cultivated with Arsenic Rich Groundwater

    Directory of Open Access Journals (Sweden)

    Piyal Bhattacharya

    2010-07-01

    Full Text Available Groundwater of many areas of West Bengal, India is severely contaminated with arsenic. The paddy soil gets con¬taminated from the groundwater and thus there is a probability of bioaccumulation of arsenic in rice plants cultivated with arsenic contaminated groundwater and soil. This study aims at assessing the level of arsenic in irrigation water and soil and to investigate the seasonal bioaccumulation of arsenic in the various parts (straw, husk and grain of the rice plant of differ¬ent varieties in the arsenic affected two blocks (Chakdaha and Ranaghat-I of Nadia district, West Bengal. It was found that the arsenic uptake in rice during the pre-monsoon season is more than that of the post-monsoon season. The accumulation of arsenic found to vary with different rice varieties; the maximum accumulation was in White minikit (0.31±0.005 mg/kg and IR 50 (0.29±0.001 mg/kg rice varieties and minimum was found to be in the Jaya rice variety (0.14±0.002 mg/kg. In rice plant maximum arsenic accumulation occurred in the straw part (0.89±0.019-1.65±0.021 mg/kg compared to the ac¬cumulation in husk (0.31±0.011-0.85±0.016 mg/kg and grain (0.14±0.002-0.31±0.005 mg/kg parts. For any rice sample concentration of arsenic in the grain did not exceed the WHO recommended permissible limit in rice (1.0 mg/kg.

  16. Arsenic release from shallow aquifers of the Hetao basin, Inner Mongolia: evidence from bacterial community in aquifer sediments and groundwater.

    Science.gov (United States)

    Li, Yuan; Guo, Huaming; Hao, Chunbo

    2014-12-01

    Indigenous microbes play crucial roles in arsenic mobilization in high arsenic groundwater systems. Databases concerning the presence and the activity of microbial communities are very useful in evaluating the potential of microbe-mediated arsenic mobilization in shallow aquifers hosting high arsenic groundwater. This study characterized microbial communities in groundwaters at different depths with different arsenic concentrations by DGGE and one sediment by 16S rRNA gene clone library, and evaluated arsenic mobilization in microcosm batches with the presence of indigenous bacteria. DGGE fingerprints revealed that the community structure changed substantially with depth at the same location. It indicated that a relatively higher bacterial diversity was present in the groundwater sample with lower arsenic concentration. Sequence analysis of 16S rRNA gene demonstrated that the sediment bacteria mainly belonged to Pseudomonas, Dietzia and Rhodococcus, which have been widely found in aquifer systems. Additionally, NO3(-)-reducing bacteria Pseudomonas sp. was the largest group, followed by Fe(III)-reducing, SO4(2-)-reducing and As(V)-reducing bacteria in the sediment sample. These anaerobic bacteria used the specific oxyanions as electron acceptor and played a significant role in reductive dissolution of Fe oxide minerals, reduction of As(V), and release of arsenic from sediments into groundwater. Microcosm experiments, using intact aquifer sediments, showed that arsenic release and Fe(III) reduction were microbially mediated in the presence of indigenous bacteria. High arsenic concentration was also observed in the batch without amendment of organic carbon, demonstrating that the natural organic matter in sediments was the potential electron donor for microbially mediated arsenic release from these aquifer sediments.

  17. Arsenic concentrations, related environmental factors, and the predicted probability of elevated arsenic in groundwater in Pennsylvania

    Science.gov (United States)

    Gross, Eliza L.; Low, Dennis J.

    2013-01-01

    Analytical results for arsenic in water samples from 5,023 wells obtained during 1969–2007 across Pennsylvania were compiled and related to other associated groundwater-quality and environmental factors and used to predict the probability of elevated arsenic concentrations, defined as greater than or equal to 4.0 micrograms per liter (µg/L), in groundwater. Arsenic concentrations of 4.0 µg/L or greater (elevated concentrations) were detected in 18 percent of samples across Pennsylvania; 8 percent of samples had concentrations that equaled or exceeded the U.S. Environmental Protection Agency’s drinking-water maximum contaminant level of 10.0 µg/L. The highest arsenic concentration was 490.0 µg/L.

  18. Assessment of arsenic contamination of groundwater and health problems in Bangladesh.

    Science.gov (United States)

    Khalequzzaman, M; Faruque, Fazlay S; Mitra, Amal K

    2005-08-01

    Excessive amounts of arsenic (As) in the groundwater in Bangladesh and neighboring states in India are a major public health problem. About 30% of the private wells in Bangladesh exhibit high concentrations of arsenic. Over half the country, 269 out of 464 administrative units, is affected. Similar problems exist in many other parts of the world, including the Unites States. This paper presents an assessment of the health hazards caused by arsenic contamination in the drinking water in Bangladesh. Four competing hypotheses, each addressing the sources, reaction mechanisms, pathways, and sinks of arsenic in groundwater, were analyzed in the context of the geologic history and land-use practices in the Bengal Basin. None of the hypotheses alone can explain the observed variability in arsenic concentration in time and space; each appears to have some validity on a local scale. Thus, it is likely that several biogeochemical processes are active among the region's various geologic environments, and that each contributes to the mobilization and release of arsenic. Additional research efforts will be needed to understand the relationships between underlying biogeochemical factors and the mechanisms for arsenic release in various geologic settings.

  19. High levels of inorganic arsenic in rice in areas where arsenic-contaminated water is used for irrigation and cooking.

    Science.gov (United States)

    Rahman, M Azizur; Hasegawa, H

    2011-10-15

    Rice is the staple food for the people of arsenic endemic South (S) and South-East (SE) Asian countries. In this region, arsenic contaminated groundwater has been used not only for drinking and cooking purposes but also for rice cultivation during dry season. Irrigation of arsenic-contaminated groundwater for rice cultivation has resulted high deposition of arsenic in topsoil and uptake in rice grain posing a serious threat to the sustainable agriculture in this region. In addition, cooking rice with arsenic-contaminated water also increases arsenic burden in cooked rice. Inorganic arsenic is the main species of S and SE Asian rice (80 to 91% of the total arsenic), and the concentration of this toxic species is increased in cooked rice from inorganic arsenic-rich cooking water. The people of Bangladesh and West Bengal (India), the arsenic hot spots in the world, eat an average of 450g rice a day. Therefore, in addition to drinking water, dietary intake of arsenic from rice is supposed to be another potential source of exposure, and to be a new disaster for the population of S and SE Asian countries. Arsenic speciation in raw and cooked rice, its bioavailability and the possible health hazard of inorganic arsenic in rice for the population of S and SE Asia have been discussed in this review. Copyright © 2011 Elsevier B.V. All rights reserved.

  20. Groundwater arsenic contamination and its health effects in India

    Science.gov (United States)

    Chakraborti, Dipankar; Rahman, Mohammad Mahmudur; Das, Bhaskar; Chatterjee, Amit; Das, Dipankar; Nayak, Biswajit; Pal, Arup; Chowdhury, Uttam Kumar; Ahmed, Sad; Biswas, Bhajan Kumar; Sengupta, Mrinal Kumar; Hossain, Md. Amir; Samanta, Gautam; Roy, M. M.; Dutta, Rathindra Nath; Saha, Khitish Chandra; Mukherjee, Subhas Chandra; Pati, Shyamapada; Kar, Probir Bijoy; Mukherjee, Adreesh; Kumar, Manoj

    2017-03-01

    During a 28-year field survey in India (1988-2016), groundwater arsenic contamination and its health effects were registered in the states of West Bengal, Jharkhand, Bihar and Uttar Pradesh in the Ganga River flood plain, and the states of Assam and Manipur in the flood plain of Brahamaputra and Imphal rivers. Groundwater of Rajnandgaon village in Chhattisgarh state, which is not in a flood plain, is also arsenic contaminated. More than 170,000 tubewell water samples from the affected states were analyzed and half of the samples had arsenic >10 μg/L (maximum concentration 3,700 μg/L). Chronic exposure to arsenic through drinking water causes various health problems, like dermal, neurological, reproductive and pregnancy effects, cardiovascular effects, diabetes mellitus, diseases of the respiratory and gastrointestinal systems, and cancers, typically involving the skin, lungs, liver, bladder, etc. About 4.5% of the 8,000 children from arsenic-affected villages of affected states were registered with mild to moderate arsenical skin lesions. In the preliminary survey, more than 10,000 patients were registered with different types of arsenic-related signs and symptoms, out of more than 100,000 people screened from affected states. Elevated levels of arsenic were also found in biological samples (urine, hair, nails) of the people living in affected states. The study reveals that the population who had severe arsenical skin lesions may suffer from multiple Bowens/cancers in the long term. Some unusual symptoms, such as burning sensation, skin itching and watering of eyes in the presence of sun light, were also noticed in arsenicosis patients.

  1. Groundwater arsenic contamination and its health effects in India

    Science.gov (United States)

    Chakraborti, Dipankar; Rahman, Mohammad Mahmudur; Das, Bhaskar; Chatterjee, Amit; Das, Dipankar; Nayak, Biswajit; Pal, Arup; Chowdhury, Uttam Kumar; Ahmed, Sad; Biswas, Bhajan Kumar; Sengupta, Mrinal Kumar; Hossain, Md. Amir; Samanta, Gautam; Roy, M. M.; Dutta, Rathindra Nath; Saha, Khitish Chandra; Mukherjee, Subhas Chandra; Pati, Shyamapada; Kar, Probir Bijoy; Mukherjee, Adreesh; Kumar, Manoj

    2017-06-01

    During a 28-year field survey in India (1988-2016), groundwater arsenic contamination and its health effects were registered in the states of West Bengal, Jharkhand, Bihar and Uttar Pradesh in the Ganga River flood plain, and the states of Assam and Manipur in the flood plain of Brahamaputra and Imphal rivers. Groundwater of Rajnandgaon village in Chhattisgarh state, which is not in a flood plain, is also arsenic contaminated. More than 170,000 tubewell water samples from the affected states were analyzed and half of the samples had arsenic >10 μg/L (maximum concentration 3,700 μg/L). Chronic exposure to arsenic through drinking water causes various health problems, like dermal, neurological, reproductive and pregnancy effects, cardiovascular effects, diabetes mellitus, diseases of the respiratory and gastrointestinal systems, and cancers, typically involving the skin, lungs, liver, bladder, etc. About 4.5% of the 8,000 children from arsenic-affected villages of affected states were registered with mild to moderate arsenical skin lesions. In the preliminary survey, more than 10,000 patients were registered with different types of arsenic-related signs and symptoms, out of more than 100,000 people screened from affected states. Elevated levels of arsenic were also found in biological samples (urine, hair, nails) of the people living in affected states. The study reveals that the population who had severe arsenical skin lesions may suffer from multiple Bowens/cancers in the long term. Some unusual symptoms, such as burning sensation, skin itching and watering of eyes in the presence of sun light, were also noticed in arsenicosis patients.

  2. Groundwater dynamics and arsenic mobilisation in Bangladesh: a national-scale characterisation

    OpenAIRE

    Shamsudduha, M.

    2011-01-01

    Elevated arsenic (As) concentrations in groundwater-fed drinking water supplies in Bangladesh are a major public health problem but the hydrogeological conditions that give rise to the mobilisation and regional-scale distribution of As in shallow groundwater remain unknown. Published hypotheses developed from highly localised case studies are, to date, untested regionally and contradictory. My doctoral thesis makes a novel and substantial contribution to knowledge of the relationship between ...

  3. Hydrogeochemical assessment of arsenic in groundwater and its policy implication: a case study in Terai Basin, Nepal

    Science.gov (United States)

    Gurung, J. K.; Upreti, B. N.; Kansakar, D. R.

    2007-12-01

    Arsenic contamination at levels above the WHO guideline (10 ìg/l) in groundwater is a worldwide problem due to its detrimental effects on health and now known to be a problem also in the Terai Basin of Nepal, posing a serious threat to more than 10 million people. The distribution of arsenic in the basin, however, is patchy. The study emphasizes on the three different types of research into an interdisciplinary package that can be immediately useful to government agencies in Nepal trying to deal with groundwater contamination. They are: hydrogeological assessment of water sources and flow, geochemical analysis of groundwater, and assessment of practical public policy. Basic geochemical analysis gives the abundance and distribution of arsenic along with other physico-chemical parameters of groundwater, whereas, the hydrogeological assessment as an integral part of this study that assist in determining process of mobilization or attenuation of arsenic. Arsenic levels and other key parameters mainly pH, electrical conductivity, chemical oxygen demand, iron, and biological parameter as E-coli were observed at the various locations with different transmissivity values. The study suggests that the flushing rate of an aquifer plays an important role in arsenic content. High flushing rates of an aquifer lead to low levels of arsenic, however the mechanism of this process is still under study. Transmissivity the property of an aquifer that measures the rate at which ground water moves horizontally through a unit is the main factor for controlling flushing. Concentration maps overlaying the base transmissivity map reveals relation of groundwater movement and arsenic concentration. Understanding the relationship between groundwater movement and arsenic content helps planners protect uncontaminated aquifers from future contamination. Also assessment of public policy related to groundwater has identified important changes needed in the existing policy.

  4. Improved Sustainability of Water Supply Options in Areas with Arsenic-Impacted Groundwater

    Directory of Open Access Journals (Sweden)

    Edward A. McBean

    2013-11-01

    Full Text Available The supply of water for rural populations in developing countries continues to present enormous problems, particularly where there is arsenic contamination in the groundwater, as exists over significant parts of Bangladesh. In response, improvements in the sustainability of water supplies are feasible through the use of a combination of water sources wherein rainwater harvesting is employed for a portion of the year. This can potentially reduce the duration of the year during which arsenic-contaminated groundwater is utilized. As demonstrated, a rainwater cistern volume of 0.5 m3 in the Jessore district area of Bangladesh can provide rainwater for periods averaging 266 days of the year, which allows groundwater at 184 µg/L arsenic to be used as a water supply for the remainder of the year. This dual supply approach provides the body burden equivalent to the interim drinking water guideline of arsenic concentration of 50 µg/L for 365 days of the year (assuming the water consumption rate is 4 L/cap/day for a family of five with a rainwater collection area of 15 m2. If the water use rate is 20 L/cap/day, the same cistern can provide water for 150 days of the year; however, although this is insufficient to supply water to meet the body burden equivalent guideline of 50 µg/L. Results are provided also for different rooftop areas, sizes of cisterns and alternative arsenic guidelines [World Health Organization (WHO and Bangladeshi]. These findings provide useful guidelines on supply options to meet sustainability targets of water supply. However, they also demonstrate that the use of cisterns cannot assist the meeting of the 10 µg/L WHO target arsenic body burden, if the arsenic contamination in the groundwater is high (e.g., at 100 µg/L.

  5. Hair and toenail arsenic concentrations of residents living in areas with high environmental arsenic concentrations.

    OpenAIRE

    Hinwood, Andrea L; Sim, Malcolm R; Jolley, Damien; de Klerk, Nick; Bastone, Elisa B; Gerostamoulos, Jim; Drummer, Olaf H

    2003-01-01

    Surface soil and groundwater in Australia have been found to contain high concentrations of arsenic. The relative importance of long-term human exposure to these sources has not been established. Several studies have investigated long-term exposure to environmental arsenic concentrations using hair and toenails as the measure of exposure. Few have compared the difference in these measures of environmental sources of exposure. In this study we aimed to investigate risk factors for elevated hai...

  6. Natural Arsenic Pollution of Groundwater in Mining Zones of Mexico

    Science.gov (United States)

    Armienta, M. A.; Rodriguez, R.; Villasennor, G.; Romero, F.; Talavera, O.; Ceniceros, N.; Aguayo, A.; Cruz, O.

    2007-05-01

    Arsenic concentrations exceeding drinking-water standards have been measured in groundwater of various areas of Mexico. This is a relevant public health problem since groundwater supplies most drinking water of the country. Although a natural source has been proposed as the cause of water contamination at most sites, the specific processes releasing As have only been identified in a few aquifers. The geological characteristics of Mexico including volcanic, geothermal, and highly mineralized zones constitute favorable environments for As occurrence. Furthermore, As-abundance in bedrock has lead Mexico to be one of the major world As-producers. As-bearing minerals like arsenopyrite, scorodite, mimetite, adamite, tennantite and nickeline can be found in several zones. Besides, arsenic may be a minor component of Fe, Ag, Cu, Pb, Zn, and Au ores. While thousands of people have been chronically exposed to As, arsenic-related health effects have been documented only for residents at some Mexican locations, like Comarca Lagunera, Zimapan, and Acambaro. Water-rock interactions may release As to water in mining areas, but ore extraction and processing produce surface wastes that can also release As to groundwater. Investigations developed in two historical mining zones revealed different As contents in groundwater. At Zimapan, a semi-arid area about 250 km NE of Mexico City, abundant arsenopyrite and hydrogeological conditions produced high As concentrations in deep wells exploited for drinking water supply. Oxidation and dissolution of As-bearing minerals mainly arsenopyrite, scorodite and tennantite released As to the fractured deep limestone aquifer. In addition, mining operations polluted shallow wells. In contrast, low levels of As were detected in wells near mine tailings in the warm sub-humid zone of Taxco, Guerrero. To explain those differences, the mineralogy and the geochemical processes occurring in tailings at both areas were studied. Results showed that besides

  7. Characterisation of organic matter associated with groundwater arsenic in reducing aquifers of southwestern Taiwan

    Energy Technology Data Exchange (ETDEWEB)

    Al Lawati, Wafa M. [School of Earth, Atmospheric and Environmental Sciences, Williamson Research Centre for Molecular Environmental Science, University of Manchester, Manchester (United Kingdom); Higher College of Technology, Ministry of Manpower, Muscat (Oman); Jean, Jiin-Shuh [Department of Earth Sciences, National Cheng Kung University, 1 University Road, Tainan 701, Taiwan (China); Kulp, Thomas R. [Department of Earth Sciences and Environmental Studies, State University of New York, Binghamton, NY (United States); Lee, Ming-Kuo [Department of Geology and Geography, Auburn University, Auburn, AL (United States); Polya, David A. [School of Earth, Atmospheric and Environmental Sciences, Williamson Research Centre for Molecular Environmental Science, University of Manchester, Manchester (United Kingdom); Liu, Chia-Chuan [Department of Earth Sciences, National Cheng Kung University, 1 University Road, Tainan 701, Taiwan (China); Dongen, Bart E. van, E-mail: Bart.vanDongen@manchester.ac.uk [School of Earth, Atmospheric and Environmental Sciences, Williamson Research Centre for Molecular Environmental Science, University of Manchester, Manchester (United Kingdom)

    2013-11-15

    Highlights: ► First lipid analysis of Taiwanese aquifer sediments from groundwater As-prone region. ► Both plant-derived terrestrial and mature hydrocarbon lipid sources identified. ► Organic matter sources similar to those of other high As groundwater aquifers. ► Groundwater arsenic at depth controlled by biotic As mobilisation processes. ► Biotic As mobilisation not controlled by a specific source of analysed organic matter. -- Abstract: Arsenic (As) in groundwaters extensively used by people across the world constitutes a serious public health threat. The importance of organic matter (OM) as an electron donor in microbially-mediated reduction of As(V) or Fe(III)-bearing As-host minerals leading to mobilisation of solid-phase arsenic is widely recognised. Notwithstanding this, there are few studies characterising OM in such aquifers and, in particular, there is a dearth of data from the classic arsenic bearing aquifers in southwestern Taiwan. Organic geochemical analyses of sediments from a known groundwater arsenic hot-spot in southwestern Taiwan revealed contributions of thermally mature and plant derived origin, consistent with OM sources in all other Asian groundwater aquifer sediments analysed to date, indicating comparable sources and routes of OM transfer. The combined results of amended As(V) reduction assays with the organic geochemical analysis revealed that the microbiological process of dissimilatory As(V) reduction is active in this aquifer, but it is not controlled by a specific source of analysed OM. These indicate that (i) part of the OM that was considered to be less bio-available could still be used as an electron donor or (ii) other electron donors, not analysed in present study, could be controlling the rate of As release.

  8. Distributional patterns of arsenic concentrations in contaminant plumes offer clues to the source of arsenic in groundwater at landfills

    Science.gov (United States)

    Harte, Philip T.

    2015-01-01

    The distributional pattern of dissolved arsenic concentrations from landfill plumes can provide clues to the source of arsenic contamination. Under simple idealized conditions, arsenic concentrations along flow paths in aquifers proximal to a landfill will decrease under anthropogenic sources but potentially increase under in situ sources. This paper presents several conceptual distributional patterns of arsenic in groundwater based on the arsenic source under idealized conditions. An example of advanced subsurface mapping of dissolved arsenic with geophysical surveys, chemical monitoring, and redox fingerprinting is presented for a landfill site in New Hampshire with a complex flow pattern. Tools to assist in the mapping of arsenic in groundwater ultimately provide information on the source of contamination. Once an understanding of the arsenic contamination is achieved, appropriate remedial strategies can then be formulated.

  9. Arsenic Contaminated Groundwater and Its Treatment Options in Bangladesh

    Directory of Open Access Journals (Sweden)

    Sayedur Rahman Chowdhury

    2012-12-01

    Full Text Available Arsenic (As causes health concerns due to its significant toxicity and worldwide presence in drinking water and groundwater. The major sources of As pollution may be natural process such as dissolution of As-containing minerals and anthropogenic activities such as percolation of water from mines, etc. The maximum contaminant level for total As in potable water has been established as 10 µg/L. Among the countries facing As contamination problems, Bangladesh is the most affected. Up to 77 million people in Bangladesh have been exposed to toxic levels of arsenic from drinking water. Therefore, it has become an urgent need to provide As-free drinking water in rural households throughout Bangladesh. This paper provides a comprehensive overview on the recent data on arsenic contamination status, its sources and reasons of mobilization and the exposure pathways in Bangladesh. Very little literature has focused on the removal of As from groundwaters in developing countries and thus this paper aims to review the As removal technologies and be a useful resource for researchers or policy makers to help identify and investigate useful treatment options. While a number of technological developments in arsenic removal have taken place, we must consider variations in sources and quality characteristics of As polluted water and differences in the socio-economic and literacy conditions of people, and then aim at improving effectiveness in arsenic removal, reducing the cost of the system, making the technology user friendly, overcoming maintenance problems and resolving sludge management issues.

  10. Arsenic Contaminated Groundwater and Its Treatment Options in Bangladesh

    Science.gov (United States)

    Jiang, Jia-Qian; Ashekuzzaman, S. M.; Jiang, Anlun; Sharifuzzaman, S. M.; Chowdhury, Sayedur Rahman

    2012-01-01

    Arsenic (As) causes health concerns due to its significant toxicity and worldwide presence in drinking water and groundwater. The major sources of As pollution may be natural process such as dissolution of As-containing minerals and anthropogenic activities such as percolation of water from mines, etc. The maximum contaminant level for total As in potable water has been established as 10 µg/L. Among the countries facing As contamination problems, Bangladesh is the most affected. Up to 77 million people in Bangladesh have been exposed to toxic levels of arsenic from drinking water. Therefore, it has become an urgent need to provide As-free drinking water in rural households throughout Bangladesh. This paper provides a comprehensive overview on the recent data on arsenic contamination status, its sources and reasons of mobilization and the exposure pathways in Bangladesh. Very little literature has focused on the removal of As from groundwaters in developing countries and thus this paper aims to review the As removal technologies and be a useful resource for researchers or policy makers to help identify and investigate useful treatment options. While a number of technological developments in arsenic removal have taken place, we must consider variations in sources and quality characteristics of As polluted water and differences in the socio-economic and literacy conditions of people, and then aim at improving effectiveness in arsenic removal, reducing the cost of the system, making the technology user friendly, overcoming maintenance problems and resolving sludge management issues. PMID:23343979

  11. Groundwater arsenic contamination in Manipur, one of the seven North-Eastern Hill states of India: a future danger

    Science.gov (United States)

    Chakraborti, Dipankar; Singh, E. Jayantakumar; Das, Bhaskar; Shah, Babar Ali; Hossain, M. Amir; Nayak, Bishwajit; Ahamed, Sad; Singh, N. Rajmuhon

    2008-11-01

    Manipur State, with a population of 2.29 million, is one of the seven North-Eastern Hill states in India, and is severely affected by groundwater arsenic contamination. Manipur has nine districts out of which four are in Manipur Valley where 59% of the people live on 10% of the land. These four districts are all arsenic contaminated. We analysed water samples from 628 tubewells for arsenic out of an expected total 2,014 tubewells in the Manipur Valley. Analyzed samples, 63.3%, contained >10 μg/l of arsenic, 23.2% between 10 and 50 μg/l, and 40% >50 μg/l. The percentages of contaminated wells above 10 and 50 μg/l are higher than in other arsenic affected states and countries of the Ganga-Meghna-Brahmaputra (GMB) Plain. Unlike on the GMB plains, in Manipur there is no systematic relation between arsenic concentration and the depth of tubewells. The source of arsenic in GMB Plain is sediments derived from the Himalaya and surrounding mountains. North-Eastern Hill states were formed at late phase of Himalaya orogeny, and so it will be found in the future that groundwater arsenic contamination in the valleys of other North-Eastern Hill states. Arsenic contaminated aquifers in Manipur Valley are mainly located within the Newer Alluvium. In Manipur, the high rainfall and abundant surface water resources can be exploited to avoid repeating the mass arsenic poisoning that has occurred on the GMB plains.

  12. Arsenic in groundwater of the Red River Floodplain, Vietnam

    DEFF Research Database (Denmark)

    Postma, Diederik Jan; Larsen, Flemming; Jessen, Søren

    2007-01-01

    The mobilization of arsenic (As) to the groundwater was studied in a shallow Holocene aquifer on the Red River flood plain near Hanoi, Vietnam. Results show an anoxic aquifer featuring organic carbon decomposition with redox zonation dominated by the reduction of Fe-oxides and methanogenesis....... The concentration of As increases over depth to a concentration of up to 550 μg/L. Most As is present as As(III) but some As(V) is always found. Arsenic correlates well with NH4, relating its release to organic matter decomposition and the source of As appears to be the Fe-oxides being reduced....

  13. Arsenic in groundwater of the Red River Floodplain, Vietnam

    DEFF Research Database (Denmark)

    Postma, Diederik Jan; Larsen, Flemming; Jessen, Søren

    2007-01-01

    . The concentration of As increases over depth to a concentration of up to 550 μg/L. Most As is present as As(III) but some As(V) is always found. Arsenic correlates well with NH4, relating its release to organic matter decomposition and the source of As appears to be the Fe-oxides being reduced.......The mobilization of arsenic (As) to the groundwater was studied in a shallow Holocene aquifer on the Red River flood plain near Hanoi, Vietnam. Results show an anoxic aquifer featuring organic carbon decomposition with redox zonation dominated by the reduction of Fe-oxides and methanogenesis...

  14. Arsenic in groundwater of Licking County, Ohio, 2012—Occurrence and relation to hydrogeology

    Science.gov (United States)

    Thomas, Mary Ann

    2016-02-23

    Arsenic concentrations were measured in samples from 168 domestic wells in Licking County, Ohio, to document arsenic concentrations in a wide variety of wells and to identify hydrogeologic factors associated with arsenic concentrations in groundwater. Elevated concentrations of arsenic (greater than 10.0 micrograms per liter [µg/L]) were detected in 12 percent of the wells (about 1 in 8). The maximum arsenic concentration of about 44 µg/L was detected in two wells in the same township.A subset of 102 wells was also sampled for iron, sulfate, manganese, and nitrate, which were used to estimate redox conditions of the groundwater. Elevated arsenic concentrations were detected only in strongly reducing groundwater. Almost 20 percent of the samples with iron concentrations high enough to produce iron staining (greater than 300 µg/L) also had elevated concentrations of arsenic.In groundwater, arsenic primarily occurs as two inorganic species—arsenite and arsenate. Arsenic speciation was determined for a subset of nine samples, and arsenite was the predominant species. Of the two species, arsenite is more difficult to remove from water, and is generally considered to be more toxic to humans.Aquifer and well-construction characteristics were compiled from 99 well logs. Elevated concentrations of arsenic (and iron) were detected in glacial and bedrock aquifers but were more prevalent in glacial aquifers. The reason may be that the glacial deposits typically contain more organic carbon than the Paleozoic bedrock. Organic carbon plays a role in the redox reactions that cause arsenic (and iron) to be released from the aquifer matrix. Arsenic concentrations were not significantly different for different types of bedrock (sandstone, shale, sandstone/shale, or other). However, arsenic concentrations in bedrock wells were correlated with two well-construction characteristics; higher arsenic concentrations in bedrock wells were associated with (1) shorter open intervals and

  15. A Review of Groundwater Arsenic Contamination in Bangladesh: The Millennium Development Goal Era and Beyond

    Directory of Open Access Journals (Sweden)

    Fakir Md. Yunus

    2016-02-01

    Full Text Available Arsenic contamination in drinking water has a detrimental impact on human health which profoundly impairs the quality of life. Despite recognition of the adverse health implications of arsenic toxicity, there have been few studies to date to suggest measures that could be taken to overcome arsenic contamination. After the statement in 2000 WHO Bulletin that Bangladesh has been experiencing the largest mass poisoning of population in history, we researched existing literature to assess the magnitude of groundwater arsenic contamination in Bangladesh. The literature reviewed related research that had been initiated and/or completed since the implementation of the Millennium Development Goals (MDGs under four domains: (1 extent of arsenic contamination; (2 health consequences; (3 mitigation and technologies and (4 future directions. To this means, a review matrix was established for analysis of previous literature based on these four core domains. Our findings revealed that several high-quality research articles were produced at the beginning of the MDG period, but efforts have dwindled in recent years. Furthermore, there were only a few studies conducted that focused on developing suitable solutions for managing arsenic contamination. Although the government of Bangladesh has made its population’s access to safe drinking water a priority agenda item, there are still pockets of the population that continue to suffer from arsenic toxicity due to contaminated water supplies.

  16. A Review of Groundwater Arsenic Contamination in Bangladesh: The Millennium Development Goal Era and Beyond.

    Science.gov (United States)

    Yunus, Fakir Md; Khan, Safayet; Chowdhury, Priyanka; Milton, Abul Hasnat; Hussain, Sumaira; Rahman, Mahfuzar

    2016-02-15

    Arsenic contamination in drinking water has a detrimental impact on human health which profoundly impairs the quality of life. Despite recognition of the adverse health implications of arsenic toxicity, there have been few studies to date to suggest measures that could be taken to overcome arsenic contamination. After the statement in 2000 WHO Bulletin that Bangladesh has been experiencing the largest mass poisoning of population in history, we researched existing literature to assess the magnitude of groundwater arsenic contamination in Bangladesh. The literature reviewed related research that had been initiated and/or completed since the implementation of the Millennium Development Goals (MDGs) under four domains: (1) extent of arsenic contamination; (2) health consequences; (3) mitigation and technologies and (4) future directions. To this means, a review matrix was established for analysis of previous literature based on these four core domains. Our findings revealed that several high-quality research articles were produced at the beginning of the MDG period, but efforts have dwindled in recent years. Furthermore, there were only a few studies conducted that focused on developing suitable solutions for managing arsenic contamination. Although the government of Bangladesh has made its population's access to safe drinking water a priority agenda item, there are still pockets of the population that continue to suffer from arsenic toxicity due to contaminated water supplies.

  17. Environmental Fate and Exposure Assessment for Arsenic in Groundwater

    Science.gov (United States)

    2008-08-01

    groundwater. Geology 32 (11):953-956. Lackovic, J. A., N. P. Nikolaidis, and G. M. Dobbs. 2000. Inorganic arsenic removal by zero- valent iron...from Bangladesh tube well water with filter columns containing zerovalent iron filings and sand. Environmental Science & Technology 39 (20):8032...aquifer sands from Araihazar, Bangladesh . Environmental Science & Technology 41 (10):3639-3645. Reisinger, H. J., D. R. Burris, and J. G. Hering. 2005

  18. Removal of arsenic from contaminated groundwater by solar-driven membrane distillation

    Energy Technology Data Exchange (ETDEWEB)

    Manna, Ajay K.; Sen, Mou [Environment and Membrane Technology Laboratory, Department of Chemical Engineering, National Institute of Technology, Durgapur 713209 India (India); Martin, Andrew R. [Department of Energy Technology, The Royal Institute of Technology (KTH), Stockholm (Sweden); Pal, Parimal, E-mail: parimalpal2000@yahoo.co [Environment and Membrane Technology Laboratory, Department of Chemical Engineering, National Institute of Technology, Durgapur 713209 India (India)

    2010-03-15

    Experimental investigations were carried out on removal of arsenic from contaminated groundwater by employing a new flat-sheet cross flow membrane module fitted with a hydrophobic polyvinylidenefluoride (PVDF) microfiltration membrane. The new design of the solar-driven membrane module in direct contact membrane distillation (DCMD) configuration successfully produced almost 100 per cent arsenic-free water from contaminated groundwater in a largely fouling-free operation while permitting high fluxes under reduced temperature polarization. For a feed flow rate of 0.120 m{sup 3}/h, the 0.13 mum PVDF membrane yielded a high flux of 74 kg/(m{sup 2} h) at a feed water temperature of 40 deg. C and, 95 kg/m{sup 2} h at a feed water temperature of 60 deg. C. The encouraging results show that the design could be effectively exploited in the vast arsenic-affected rural areas of South-East Asian countries blessed with abundant sunlight particularly during the critical dry season. - Solar-driven membrane distillation has the potential of removing arsenic from contaminated groundwater.

  19. ELECTROCHEMICAL REMEDIATION OF ARSENIC-CONTAMINATED GROUNDWATER — RESULTS OF PROTOTYPE FIELD TESTS IN BANGLADESH

    Energy Technology Data Exchange (ETDEWEB)

    Kowolik, K; Addy, S.E.A.; Gadgil, A.

    2009-01-01

    According to the World Health Organization (WHO), more than 50 million people in Bangladesh drink arsenic-laden water, making it the largest case of mass poisoning in human history. Many methods of arsenic removal (mostly using chemical adsorbents) have been studied, but most of these are too expensive and impractical to be implemented in poor countries such as Bangladesh. This project investigates ElectroChemical Arsenic Remediation (ECAR) as an affordable means of removing arsenic. Experiments were performed on site in Bangladesh using a prototype termed “sushi”. This device consists of carbon steel sheets that serve as electrodes wrapped into a cylinder, separated by plastic mesh and surrounded by a tube-like container that serves as a holding cell in which the water is treated electrochemically. During the electrochemical process, current is applied to both electrodes causing iron to oxidize to various forms of iron (hydr)oxides. These species bind to arsenic(V) with very high affi nity. ECAR also has the advantage that As(III), the more toxic form of arsenic, oxidizes to As(V) in situ. Only As(V) is known to complex with iron (hydr)oxides. One of the main objectives of this research is to demonstrate the ability of the new prototype to reduce arsenic concentrations in Bangladesh groundwater from >200 ppb to below the WHO limit of 10 ppb. In addition, varying fl ow rate and dosage and the effect on arsenic removal was investigated. Experiments showed that ECAR reduced Bangladeshi water with an initial arsenic concentration as high as 250 ppb to below 10 ppb. ECAR proved to be effective at dosages as high as 810 Coulombs/Liter (C/L) and as low as 386 C/L (current 1 A, voltage 12 V). These results are encouraging and provide great promise that ECAR is an effi cient method in the remediation of arsenic from contaminated groundwater. A preliminary investigation of arsenic removal trends with varying Coulombic dosage, complexation time and fi ltration methods is

  20. Groundwater chemistry and occurrence of arsenic in the Meghna floodplain aquifer, southeastern Bangladesh

    Science.gov (United States)

    Zahid, A.; Hassan, M.Q.; Balke, K.-D.; Flegr, M.; Clark, D.W.

    2008-01-01

    Dissolved major ions and important heavy metals including total arsenic and iron were measured in groundwater from shallow (25-33 m) and deep (191-318 m) tube-wells in southeastern Bangladesh. These analyses are intended to help describe geochemical processes active in the aquifers and the source and release mechanism of arsenic in sediments for the Meghna Floodplain aquifer. The elevated Cl- and higher proportions of Na+ relative to Ca2+, Mg2+, and K+ in groundwater suggest the influence by a source of Na+ and Cl-. Use of chemical fertilizers may cause higher concentrations of NH 4+ and PO 43- in shallow well samples. In general, most ions are positively correlated with Cl-, with Na+ showing an especially strong correlation with Cl-, indicating that these ions are derived from the same source of saline waters. The relationship between Cl-/HCO 3- ratios and Cl- also shows mixing of fresh groundwater and seawater. Concentrations of dissolved HCO 3- reflect the degree of water-rock interaction in groundwater systems and integrated microbial degradation of organic matter. Mn and Fe-oxyhydroxides are prominent in the clayey subsurface sediment and well known to be strong adsorbents of heavy metals including arsenic. All five shallow well samples had high arsenic concentration that exceeded WHO recommended limit for drinking water. Very low concentrations of SO 42- and NO 3- and high concentrations of dissolved Fe and PO 43- and NH 4+ ions support the reducing condition of subsurface aquifer. Arsenic concentrations demonstrate negative co-relation with the concentrations of SO 42- and NO 3- but correlate weakly with Mo, Fe concentrations and positively with those of P, PO 43- and NH 4+ ions. ?? 2007 Springer-Verlag.

  1. Adsorption of arsenic from a Nova Scotia groundwater onto water treatment residual solids.

    Science.gov (United States)

    Gibbons, Meaghan K; Gagnon, Graham A

    2010-11-01

    Water treatment residual solids were examined in batch adsorption and column adsorption experiments using a groundwater from Halifax Regional Municipality that had an average arsenic concentration of 43 μg/L (±4.2 μg/L) and a pH of 8.1. The residual solids studied in this paper were from five water treatment plants, four surface water treatment plants that utilized either alum, ferric, or lime in their treatment systems, and one iron removal plant. In batch adsorption experiments, iron-based residual solids and lime-based residual solids pre-formed similarly to GFH, a commercially-available adsorbent, while alum-based residual solids performed poorly. Langmuir isotherm modeling showed that ferric residuals had the highest adsorptive capacity for arsenic (Q(max) = 2230 mg/kg and 42,910 mg/kg), followed by GFH (Q(max) = 640 mg/kg), lime (Q(max) = 160 mg/kg) and alum (Q(max) = 93% for the ferric and lime residuals and GFH, while the maximum arsenic removal was residuals under the same conditions. In a column adsorption experiment, ferric residual solids achieved arsenic removal of >26,000 bed volumes before breakthrough past 10 μg As/L, whereas the effluent arsenic concentration from the GFH column was under the method detection limit at 28,000 bed volumes. Overall, ferric and lime water treatment residuals were promising adsorbents for arsenic adsorption from the groundwater, and alum water treatment residuals did not achieve high levels of arsenic adsorption.

  2. Rapid decadal evolution in the groundwater arsenic content of Kolkata, India and its correlation with the practices of her dwellers.

    Science.gov (United States)

    Malakar, Arindam; Islam, Samirul; Ali, Md Ashif; Ray, Sugata

    2016-10-01

    Increasing arsenic contamination in the groundwater is one of the biggest environmental challenges that the Bengal delta is facing today. Groundwater is still the main source of water for a large number of population in this region and therefore, significant presence of toxic arsenic has a direct consequence on human lives here. Moreover, arsenic also enters into the food chain through the consumed agricultural products grown in this area. Therefore, acquiring knowledge about the ever-changing map of arsenic contamination and employing adequate protective measures are of utmost importance. Here, we present a comprehensive municipal ward-wise map of the arsenic content of the shallow groundwater table of Kolkata-the most important and highly population dense city of the delta. Comparison with previously available data reveals a rapid change and the grim situation for the city. Our study suggests that it should be an immediate task of the administration to extend treated water service to the whole population of the city for direct consumption, and artificial recharge and maximum rainwater replenishment need to be taken up with utmost urgency to avoid intrusion of toxicity in biological food chains via agricultural products. We hope our study would drive the city planners to reconsider the existing urbanization and development plans of all the cities, placed over arsenic-contaminated groundwater aquifers.

  3. Confirmation of elevated arsenic levels in groundwater of Myanmar

    Science.gov (United States)

    van Geen, Alexander; Win, Kyi Htut; Zaw, Than; Naing, Win; Mey, Jacob L.; Mailloux, Brian

    2014-01-01

    Millions of villagers across South and Southeast Asia are exposed to toxic levels of arsenic (As) by drinking well water. In order to confirm field-kit results that Myanmar is also affected, a total of 55 wells were tested in the field in January 2013 and sampled for laboratory analysis across seven villages spanning a range of As contamination in the lower Ayeyarwady basin. Elevated concentrations of As (50–630 μg/L) were measured in wells up to 60 m deep and associated with high levels of Fe (up to 21 mg/L) and low concentrations of SO4 (<0.05 mg/L). Concentrations of As <10 μg/L were measured in some shallow (<30 m) grey sands and in both shallow and deep orange sands. These results indicate that the main mechanism of As release to groundwater in Myanmar is the reductive dissolution of Fe oxyhydroxides, as in the neighboring Bengal, Mekong, and Red River basins. Concentrations of As in groundwater of Myanmar are therefore unlikely to change rapidly over time and switching to existing low-As wells is a viable way of reducing exposure in the short term. However, only 17 of the 55 well owners interviewed correctly recalled the status of their well despite extensive testing in the region. A renewed effort is thus needed to test existing wells and new wells that continue to be installed and to communicate the health risks of exposure to As for infants, children, and adults. PMID:24530581

  4. Removal of Arsenic from Groundwater with Low Cost Multilayer Media

    Directory of Open Access Journals (Sweden)

    Abdus Samad

    2010-06-01

    Full Text Available A simple, low cost arsenic removal system was developed to treat arsenic contaminated ground water containing 425 ± 4.2 µg/L arsenic. The system decontaminates arsenic from water by sorption through fine particles of waste materials (Coconut husk’s ash, Refused brick dust, Stone dust and Waste newspaper of multilayer. The treatment efficiency of the process was investigated under various operating conditions that might affect the sorption/ desorption of arsenic. Sorption column method shows the optimum removal of As(III under the following conditions: initial As concentration (100 µg/L, sorbent amount (4.0 g for brick dust, 3.0 g for stone dust, 3.0 g for Coconut husk’s ash and 0.3 g for waste newspaper, particle size (<355 µm, treatment flow rate (1.4 mL/min, optimum volume (100 mL and pH (5.0. Desorption efficiencies with 2M of KOH after the treatment of groundwater were observed in the range of 78 ± 1.2% - 82 ± 1.4%. Average arsenic concentration of treated sample water was 8.30 ± 0.4 µg/L which is below the WHO guideline value for Bangladesh. Different techniques were used to measure thirteen metals, four anions with pH, conductivity, and temperature to understand the status of other species before and after treatment. The average concentrations of other inorganic constituents of health concern (Cu, Mn, Pb, Cr and Fe in treated water were below WHO guideline value for drinking water. The present study showed a new method for removal of as from ground water.

  5. Seasonal Arsenic Accumulation in Stream Sediments at a Groundwater Discharge Zone

    DEFF Research Database (Denmark)

    MacKay, Allison A.; Gan, Ping; Yu, Ran

    2014-01-01

    Seasonal changes in arsenic and iron accumulation rates were examined in the sediments of a brook that receives groundwater discharges of arsenic and reduced iron. Clean glass bead columns were deployed in sediments for known periods over the annual hydrologic cycle to monitor changes in arsenic ...

  6. Identifying occurrences of groundwater arsenic in Latin America: a continent-wide problem and challenge

    Science.gov (United States)

    Bundschuh, J.; Lopez, D.; Bhattacharya, P.; Cumbal, L.; Litter, M.

    2008-05-01

    In Argentina, Chile, Bolivia, Peru, and Mexico at least 4 million people depend on drinking water with high toxic arsenic (As) concentrations exceeding 0.05 mg/L. In most cases, arsenic originates from geogenic sources. In Argentina (and until 1970 also in Chile) over 1 percent of the country's population have been exposed to As concentrations higher than 0.05 mg/L, whereas in Bolivia, Ecuador, Nicaragua, and El Salvador, As in drinking water has been detected recently, but the extent of the problem and the numbers of people affected are yet unknown. In Argentina, As has been reported in groundwater in the Chaco-Pampean plain, where 1.2-2 million are exposed to As in drinking water with concentrations higher than 0.05 mg/L. The aquifers are affected by the leaching of volcanic glass products as the principal source of As. Besides, dissolution of volcanic rocks of the Andean chain adds As to the overland flow and infiltrating water. This explains the high As levels in drinking water of northern Chile. In this region, the principal drinking water sources are the rivers with high As concentrations (0.2 to 0.9 mg/L As). In Peru, geogenic As contaminants are present in Aricota lake, which is fed by the rivers Collazas and Salado. The central and the southern region of Bolivia's Andean highland are the areas affected by geogenic arsenic sources. In Mexico, the release of As to drinking water supplies of the Zimapan area occurs due to both, the natural dissolution/weathering of the As rich rocks and mining activities (groundwater: 0.19 to 0.65 mg/L). The Salamanca aquifer system (Guanajuato state) is naturally affected by As from geogenic sources (up to 0.28 mg/L). In addition, arsenic in groundwater was recently also reported at the south of the Baja California state. In other Latin American countries, the existence of a groundwater arsenic problem has not yet been properly assessed. This is for example the case of Nicaragua, where exposure of the population to arsenic

  7. Identifying sources and controlling factors of arsenic release in saline groundwater aquifers

    OpenAIRE

    Liu, C. -W.; Lu, K.-L.; Kao, Y.-H.; Wang, C.-J.; Maji, S.-K.; Lee, J.-F.

    2014-01-01

    An integrated hydrogeochemical study was carried out to realize the occurrence of arsenic (As) in a saline aquifer. Saline groundwater was mostly concentrated in the uppermost aquifer, and non-saline water was in the lower aquifer in the study area. High As concentrations were found in both the uppermost and lower aquifers. No correlation among salinity, well depth and As concentration was observed. Various forms of Fe oxyhydroxides were identified in the magnetic fractions,...

  8. A generalized regression model of arsenic variations in the shallow groundwater of Bangladesh

    Science.gov (United States)

    Shamsudduha, Mohammad; Taylor, Richard G.; Chandler, Richard E.

    2015-01-01

    Localized studies of arsenic (As) in Bangladesh have reached disparate conclusions regarding the impact of irrigation-induced recharge on As concentrations in shallow (≤50 m below ground level) groundwater. We construct generalized regression models (GRMs) to describe observed spatial variations in As concentrations in shallow groundwater both (i) nationally, and (ii) regionally within Holocene deposits where As concentrations in groundwater are generally high (>10 μg L-1). At these scales, the GRMs reveal statistically significant inverse associations between observed As concentrations and two covariates: (1) hydraulic conductivity of the shallow aquifer and (2) net increase in mean recharge between predeveloped and developed groundwater-fed irrigation periods. Further, the GRMs show that the spatial variation of groundwater As concentrations is well explained by not only surface geology but also statistical interactions (i.e., combined effects) between surface geology and mean groundwater recharge, thickness of surficial silt and clay, and well depth. Net increases in recharge result from intensive groundwater abstraction for irrigation, which induces additional recharge where it is enabled by a permeable surface geology. Collectively, these statistical associations indicate that irrigation-induced recharge serves to flush mobile As from shallow groundwater.

  9. Predicting geogenic arsenic contamination in shallow groundwater of south Louisiana, United States.

    Science.gov (United States)

    Yang, Ningfang; Winkel, Lenny H E; Johannesson, Karen H

    2014-05-20

    Groundwater contaminated with arsenic (As) threatens the health of more than 140 million people worldwide. Previous studies indicate that geology and sedimentary depositional environments are important factors controlling groundwater As contamination. The Mississippi River delta has broadly similar geology and sedimentary depositional environments to the large deltas in South and Southeast Asia, which are severely affected by geogenic As contamination and therefore may also be vulnerable to groundwater As contamination. In this study, logistic regression is used to develop a probability model based on surface hydrology, soil properties, geology, and sedimentary depositional environments. The model is calibrated using 3286 aggregated and binary-coded groundwater As concentration measurements from Bangladesh and verified using 78 As measurements from south Louisiana. The model's predictions are in good agreement with the known spatial distribution of groundwater As contamination of Bangladesh, and the predictions also indicate high risk of As contamination in shallow groundwater from Holocene sediments of south Louisiana. Furthermore, the model correctly predicted 79% of the existing shallow groundwater As measurements in the study region, indicating good performance of the model in predicting groundwater As contamination in shallow aquifers of south Louisiana.

  10. Groundwater arsenic contamination in Burkina Faso, West Africa: Predicting and verifying regions at risk.

    Science.gov (United States)

    Bretzler, Anja; Lalanne, Franck; Nikiema, Julien; Podgorski, Joel; Pfenninger, Numa; Berg, Michael; Schirmer, Mario

    2017-04-15

    Arsenic contamination in groundwater from crystalline basement rocks in West Africa has only been documented in isolated areas and presents a serious health threat in a region already facing multiple challenges related to water quality and scarcity. We present a comprehensive dataset of arsenic concentrations from drinking water wells in rural Burkina Faso (n=1498), of which 14.6% are above 10μg/L. Included in this dataset are 269 new samples from regions where no published water quality data existed. We used multivariate logistic regression with arsenic measurements as calibration data and maps of geology and mineral deposits as independent predictor variables to create arsenic prediction models at concentration thresholds of 5, 10 and 50μg/L. These hazard maps delineate areas vulnerable to groundwater arsenic contamination in Burkina Faso. Bedrock composed of schists and volcanic rocks of the Birimian formation, potentially harbouring arsenic-containing sulphide minerals, has the highest probability of yielding groundwater arsenic concentrations >10μg/L. Combined with population density estimates, the arsenic prediction models indicate that ~560,000 people are potentially exposed to arsenic-contaminated groundwater in Burkina Faso. The same arsenic-bearing geological formations that are positive predictors for elevated arsenic concentrations in Burkina Faso also exist in neighbouring countries such as Mali, Ghana and Ivory Coast. This study's results are thus of transboundary relevance and can act as a trigger for targeted water quality surveys and mitigation efforts. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Iron Polymerization and Arsenic Removal During In-Situ Iron Electrocoagulation in Synthetic Bangladeshi Groundwater

    Science.gov (United States)

    van Genuchten, C. M.; Pena, J.; Addy, S.; Gadgil, A.

    2010-12-01

    Millions of people worldwide are exposed to arsenic-contamination in groundwater drinking supplies. The majority of affected people live in rural Bangladesh. Electrocoagulation (EC) using iron electrodes is a promising arsenic removal strategy that is based on the generation of iron precipitates with a high affinity for arsenic through the electrochemical dissolution of a sacrificial iron anode. Many studies of iron hydrolysis in the presence of co-occurring ions in groundwater such as PO43-, SiO44-, and AsO43- suggest that these ions influence the polymerization and formation of iron oxide phases. However, the combined impact of these ions on precipitates generated by EC is not well understood. X-ray absorption spectroscopy (XAS) was used to examine EC precipitates generated in synthetic Bangladeshi groundwater (SBGW). The iron oxide structure and arsenic binding geometry were investigated as a function of EC operating conditions. As and Fe k-edge spectra were similar between samples regardless of the large range of current density (0.02, 1.1, 5.0, 100 mA/cm2) used during sample generation. This result suggests that current density does not play a large role in the formation EC precipitates in SBGW. Shell-by-shell fits of Fe K-edge data revealed the presence of a single Fe-Fe interatomic distance at approximately 3.06 Å. The absence of longer ranged Fe-Fe correlations suggests that EC precipitates consist of nano-scale chains (polymers) of FeO6 octahedra sharing equatorial edges. Shell-by-shell fits of As K-edge spectra show arsenic bound in primarily bidentate, binuclear corner sharing complexes. In this coordination geometry, arsenic prevents the formation of FeO6 corner-sharing linkages, which are necessary for 3-dimensional crystal growth. The individual and combined effects of other anions, such as PO43- and SiO44- present in SBGW are currently being investigated to determine the role of these ions in stunting crystal growth. The results provided by this

  12. Arsenic Contamination in Groundwater of Bangladesh: Perspectives on Geochemical, Microbial and Anthropogenic Issues

    Directory of Open Access Journals (Sweden)

    Shafi M. Tareq

    2011-11-01

    Full Text Available A groundwater, sediment and soil chemistry and mineralogical study has been performed to investigate the sources and mobilization process of Arsenic (As in shallow aquifers of Bangladesh. The groundwater from the shallow aquifers is characterized by high concentrations of Arsenic (47.5–216.8 µg/L, iron (0.85–5.83 mg/L, and phosphate, along with high electrical conductivity (EC. The groundwater has both very low oxidation-reduction potential (Eh and dissolved oxygen (DO values indicating reducing conditions. By contrast, the deep aquifers and surface waters (pond, canal have very low concentrations of Arsenic ( < 6 µg/L, iron (0.12–0.39 mg/L, and phosphate along with a relatively low EC. Furthermore, the values of Eh and DO are high, indicating oxic to suboxic conditions. Arsenic is inversely correlated with Eh values in the upper aquifer, whereas no relationship in the deeper aquifer is observed. These results suggest that As mobilization is clearly linked to the development of reducing conditions. The clayey silt, enriched in Fe, Mn, Al oxides and organic matter, and deposited in the middle unit of shallow aquifers, contains moderately high concentrations of As, whereas the sediments of deep aquifers and silty mud surface soils from paddy fields and ponds contain a low content of As (Daudkandi area. Arsenic is strongly correlated with the concentrations of Fe, Mn and Al oxides in the core samples from the Daudkandi and Marua areas. Arsenic is present in the oxide phase of Fe and Mn, phyllosilicate minerals and in organic matter in sediments. This study suggests that adsorption or precipitation of As-rich Fe oxyhydroxide on the surface or inner sites of biotite might be responsible for As concentrations found in altered biotite minerals by Seddique et al. Microbially or geochemically mediated reductive dissolution of Fe oxyhydroxides is the main mechanism for As release. The reducing conditions are caused by respiratory decomposition of

  13. Subsidence Serves as an Indicator of Groundwater Arsenic Risk in the San Joaquin Valley, California

    Science.gov (United States)

    Smith, R.; Knight, R. J.; Fendorf, S. E.

    2016-12-01

    Groundwater arsenic concentrations dominantly result from anaerobic conditions. Within aquifers, clays are typically the major hosts of solid-phase arsenic, and clay layers often have restricted oxygen supply, resulting in anaerobic conditions and the concomitant relase of arsenic to groundwater. But it is not until water is drawn from the clay layers, through over-pumping of aquifers, that arsenic enters the water supply. Due to the mechanical properties of clays, the volume of groundwater withdrawn is effectively approximated by their vertical deformation, the sum of which is expressed at the surface as subsidence. As a result, subsidence can serve as an indicator, or "early warning system", of the presence of arsenic in the pumped groundwater. In the San Joaquin Valley of California, there has been significant subsidence due to groundwater extraction from clays for nearly a century. Historical subsidence in this area has been measured with leveling surveys, GPS and extensometers, and has been reproduced in groundwater models. More recent subsidence can be measured directly using Interferometric Synthetic Aperture Radar (InSAR). We use recent (post-2007) arsenic level data from the southern portion of the San Joaquin Valley to train a random forest model. Predictors in the model include historical (pre-2002) estimates of subsidence, more recent (2007-2011) InSAR estimates of subsidence, and other predictors representing additional mechanisms that could affect arsenic levels in groundwater, such as groundwater flow, redox potential and position in the basin. We find that recent subsidence is a strong predictor of arsenic levels; historical subsidence could have some impact but is less significant. These results indicate that avoiding over-pumping of the aquifer may improve water quality over a time period on the order of 10 years. Incorporating subsidence into arsenic prediction maps can improve our ability to identify and manage areas that have a higher risk of

  14. Regional modeling of groundwater flow and arsenic transport in the Bengal Basin: challenges of scale and complexity (Invited)

    Science.gov (United States)

    Michael, H. A.; Voss, C. I.

    2009-12-01

    Widespread arsenic poisoning is occurring in large areas of Bangladesh and West Bengal, India due to high arsenic levels in shallow groundwater, which is the primary source of irrigation and drinking water in the region. The high-arsenic groundwater exists in aquifers of the Bengal Basin, a huge sedimentary system approximately 500km x 500km wide and greater than 15km deep in places. Deeper groundwater (>150m) is nearly universally low in arsenic and a potential source of safe drinking water, but evaluation of its sustainability requires understanding of the entire, interconnected regional aquifer system. Numerical modeling of flow and arsenic transport in the basin introduces problems of scale: challenges in representing the system in enough detail to produce meaningful simulations and answer relevant questions while maintaining enough simplicity to understand controls on processes and operating within computational constraints. A regional groundwater flow and transport model of the Bengal Basin was constructed to assess the large-scale functioning of the deep groundwater flow system, the vulnerability of deep groundwater to pumping-induced migration from above, and the effect of chemical properties of sediments (sorption) on sustainability. The primary challenges include the very large spatial scale of the system, dynamic monsoonal hydrology (small temporal scale fluctuations), complex sedimentary architecture (small spatial scale heterogeneity), and a lack of reliable hydrologic and geologic data. The approach was simple. Detailed inputs were reduced to only those that affect the functioning of the deep flow system. Available data were used to estimate upscaled parameter values. Nested small-scale simulations were performed to determine the effects of the simplifications, which include treatment of the top boundary condition and transience, effects of small-scale heterogeneity, and effects of individual pumping wells. Simulation of arsenic transport at the large

  15. Influence of irrigation practices on arsenic mobilization: Evidence from isotope composition and Cl/Br ratios in groundwater from Datong Basin, northern China

    Science.gov (United States)

    Xie, Xianjun; Wang, Yanxin; Su, Chunli; Li, Junxia; Li, Mengdi

    2012-03-01

    SummaryEnvironment isotopes (δ18O and δ2H) and Cl/Br ratios in groundwater have been used to trace groundwater recharge and geochemical processes for arsenic contamination in Datong Basin. The arsenic concentrations of groundwater samples ranged from 0.4 to 434.9 μg/L with the average of 51.2 μg/L, which exceeded China's drinking water standard (10 μg/L). All the groundwater samples are plotted on or close to the meteoric water line of the δ18O vs. δ2H plot, indicating their meteoric origin. The relationship between δ18O values and Cl/Br ratios and Cl concentrations demonstrate that leaching and mixing are the dominant processes affecting the distribution of high arsenic groundwater in this area. The observed non-linearity in the trend between δ18O and arsenic concentration is due to combined effects of mixing and leaching. The similarity of the trend in Cl/Br ratios and δ18O values for high arsenic groundwater demonstrate that extensive leaching of irrigation return and salt flushing water flow could be the dominant process driving arsenic mobilization in the groundwater system. Moreover, the long term irrigation practice can cause the drastic change of the biogeochemical and redox condition of in the aquifer system, which in turn promotes the mobilization of arsenic. Therefore, groundwater pumping for irrigation in this area of waterborne endemic arsenic poisoning should be under strict control to protect groundwater quality in this area.

  16. Prediction of Groundwater Arsenic Contamination using Geographic Information System and Artificial Neural Network

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    Md. Moqbul Hossain

    2013-01-01

    Full Text Available Ground water arsenic contamination is a well known health and environmental problem in Bangladesh. Sources of this heavy metal are known to be geogenic, however, the processes of its release into groundwater are poorly understood phenomena. In quest of mitigation of the problem it is necessary to predict probable contamination before it causes any damage to human health. Hence our research has been carried out to find the factor relations of arsenic contamination and develop an arsenic contamination prediction model. Researchers have generally agreed that the elevated concentration of arsenic is affected by several factors such as soil reaction (pH, organic matter content, geology, iron content, etc. However, the variability of concentration within short lateral and vertical intervals, and the inter-relationships of variables among themselves, make the statistical analyses highly non-linear and difficult to converge with a meaningful relationship. Artificial Neural Networks (ANN comes in handy for such a black box type problem. This research uses Back propagation Neural Networks (BPNN to train and validate the data derived from Geographic Information System (GIS spatial distribution grids. The neural network architecture with (6-20-1 pattern was able to predict the arsenic concentration with reasonable accuracy.

  17. Labile Organic Carbon in Recharge and its Impact on Groundwater Arsenic Concentrations in Bangladesh

    Science.gov (United States)

    Neumann, R. B.; Ashfaque, K. N.; Badruzzaman, A. M.; Ali, M.; Shoemaker, J. K.; Harvey, C. F.

    2009-12-01

    Researchers have puzzled over the origin of dissolved arsenic in the aquifers of the Ganges Delta since widespread arsenic poisoning from groundwater was publicized two decades ago. Previous work has concluded that biological oxidation of organic carbon drives geochemical transformations that mobilize arsenic from sediments; however, the source of the organic carbon that fuels these processes remains controversial. A combined hydrologic and biogeochemical analysis of a typical site in Bangladesh, where constructed ponds and groundwater-irrigated rice fields are the main sources of recharge, shows that only recharge through pond sediments provides the biologically degradable organic carbon that can drive arsenic mobilization. Numerical groundwater simulations as well as chemical and isotopic indicators suggest that contaminated groundwater originates from excavated ponds and that water originating from rice fields is low in arsenic. In fact, rice fields act as an arsenic sink. Irrigation moves arsenic-rich groundwater from the aquifers and deposits it on the rice fields. Most of the deposited arsenic does not return to the aquifers; it is sorbed by the field’s surface soil and bunds, and is swept away in the monsoon floods. The findings indicate that patterns of arsenic contamination in the shallow aquifer are due to recharge-source variation and complex three-dimensional flow.

  18. Geochemical controls of elevated arsenic concentrations in groundwater, Ester Dome, Fairbanks district, Alaska

    Science.gov (United States)

    Verplanck, P.L.; Mueller, S.H.; Goldfarb, R.J.; Nordstrom, D.K.; Youcha, E.K.

    2008-01-01

    Ester Dome, an upland area near Fairbanks, Alaska, was chosen for a detailed hydrogeochemical study because of the previously reported elevated arsenic in groundwater, and the presence of a large set of wells amenable to detailed sampling. Ester Dome lies within the Fairbanks mining district, where gold-bearing quartz veins, typically containing 2-3??vol.% sulfide minerals (arsenopyrite, stibnite, and pyrite), have been mined both underground and in open cuts. Gold-bearing veins on Ester Dome occur in shear zones and the sulfide minerals in these veins have been crushed to fine-grained material by syn- or post-mineralization movement. Groundwater at Ester Dome is circumneutral, Ca-HCO3 to Ca-SO4 type, and ranges from dilute (specific conductance of 48????S/cm) to more concentrated (specific conductance as high as 2070????S/cm). In general, solute concentrations increase down hydrologic gradient. Redox species indicate that the groundwaters range from oxic to sub-oxic (low dissolved oxygen, Fe(III) reduction, no SO4 reduction). Waters with the highest Fe concentrations, as high as 10.7??mg/L, are the most anoxic. Dissolved As concentrations range from iron oxyhydroxides, control the arsenic chemistry. Furthermore, As concentrations do not covary with other constituents that form anions and oxyanions in solution (e.g., HCO3, Mo, F, or U) such that desorption of arsenic from clays or oxides also does not control arsenic mobility. Oxidation of arsenopyrite and dissolution of scorodite, in the near-surface environment appears to be the primary control of dissolved As in this upland area. More specifically, the elevated As concentrations are spatially associated with sulfidized shear zones and localities of gold-bearing quartz veins. Consistent with this interpretation, elevated dissolved Sb concentrations (as high as 59????g/L), also correlated with occurrences of hypogene sulfide minerals, were measured in samples with high dissolved As concentrations.

  19. Arsenic contamination of groundwater: Mitigation strategies and policies

    Science.gov (United States)

    Alaerts, Guy J.; Khouri, Nadim

    Contamination of groundwater by arsenic from natural geochemical sources is at present a most serious challenge in the planning of large-scale use of groundwater for drinking and other purposes. Recent improvements in detection limits of analytical instruments are allowing the correlation of health impacts such as cancer with large concentrations of arsenic in groundwater. However, there are at present no known large-scale technological solutions for the millions of people-mostly rural-who are potentially affected in developing countries. An overall framework of combating natural resource degradation is combined with case studies from Chile, Mexico, Bangladesh and elsewhere to arrive at a set of strategic recommendations for the global, national and local dimensions of the arsenic ``crisis''. The main recommendations include: the need for flexibility in the elaboration of any arsenic mitigation strategy, the improvement and large-scale use of low-cost and participatory groundwater quality testing techniques, the need to maintain consistent use of key lessons learned worldwide in water supply and sanitation and to integrate arsenic as just one other factor in providing a sustainable water supply, and the following of distinct but communicable tracks between arsenic-related developments and enhanced, long-term, sustainable water supplies. La contamination des eaux souterraines par l'arsenic provenant de sources naturelles est actuellement un sujet des plus graves dans l'organisation d'un recours à grande échelle des eaux souterraines pour la boisson et d'autres usages. De récentes améliorations dans les limites de détection des équipements analytiques permettent de corréler les effets sur la santé tels que le cancer à de fortes concentrations en arsenic dans les eaux souterraines. Toutefois, il n'existe pas actuellement de solutions technologiques à grande échelle connues pour des millions de personnes, surtout en zones rurales, qui sont potentiellement

  20. Stratigraphic and geochemical controls on naturally occurring arsenic in groundwater, eastern Wisconsin, USA

    Science.gov (United States)

    Schreiber, M. E.; Simo, J. A.; Freiberg, P. G.

    High arsenic concentrations (up to 12,000μg/L) have been measured in groundwater from a confined sandstone aquifer in eastern Wisconsin. The main arsenic source is a sulfide-bearing secondary cement horizon (SCH) that has variable thickness, morphology, and arsenic concentrations. Arsenic occurs in pyrite and marcasite as well as in iron oxyhydroxides but not as a separate arsenopyrite phase. Nearly identical sulfur isotopic signatures in pyrite and dissolved sulfate and the correlation between dissolved sulfate, iron, and arsenic concentrations suggest that sulfide oxidation is the dominant process controlling arsenic release to groundwater. However, arsenic-bearing oxyhydroxides can potentially provide another arsenic source if reducing conditions develop or if they are transported as colloids in the aquifer. Analysis of well data indicates that the intersection of the SCH with static water levels measured in residential wells is strongly correlated with high concentrations of arsenic in groundwater. Field and laboratory data suggest that the most severe arsenic contamination is caused by localized borehole interactions of air, water, and sulfides. Although arsenic contamination is caused by oxidation of naturally occurring sulfides, it is influenced by water-level fluctuations caused by municipal well pumping or climate changes, which can shift geographic areas in which contamination occurs. Résumé De fortes concentrations en arsenic, jusqu'à 12000μg/L, ont été mesurées dans l'eau souterraine d'un aquifère gréseux captif, dans l'est du Wisconsin. La principale source d'arsenic est un horizon à cimentation secondaire (SCH) comportant des sulfures, dont l'épaisseur, la morphologie et les concentrations en arsenic sont variables. L'arsenic est présent dans la pyrite et dans la marcassite, de même que dans des oxy-hydroxydes de fer, mais non pas dans une phase séparée d'arsénopyrite. Les signatures isotopiques du soufre presque identiques dans la

  1. A generalized regression model of arsenic variations in the shallow groundwater of Bangladesh

    Science.gov (United States)

    Taylor, Richard G.; Chandler, Richard E.

    2015-01-01

    Abstract Localized studies of arsenic (As) in Bangladesh have reached disparate conclusions regarding the impact of irrigation‐induced recharge on As concentrations in shallow (≤50 m below ground level) groundwater. We construct generalized regression models (GRMs) to describe observed spatial variations in As concentrations in shallow groundwater both (i) nationally, and (ii) regionally within Holocene deposits where As concentrations in groundwater are generally high (>10 μg L−1). At these scales, the GRMs reveal statistically significant inverse associations between observed As concentrations and two covariates: (1) hydraulic conductivity of the shallow aquifer and (2) net increase in mean recharge between predeveloped and developed groundwater‐fed irrigation periods. Further, the GRMs show that the spatial variation of groundwater As concentrations is well explained by not only surface geology but also statistical interactions (i.e., combined effects) between surface geology and mean groundwater recharge, thickness of surficial silt and clay, and well depth. Net increases in recharge result from intensive groundwater abstraction for irrigation, which induces additional recharge where it is enabled by a permeable surface geology. Collectively, these statistical associations indicate that irrigation‐induced recharge serves to flush mobile As from shallow groundwater. PMID:27524841

  2. In-situ arsenic removal during groundwater recharge through unsaturated alluvium

    Science.gov (United States)

    O'Leary, David; Izbicki, John; T.J. Kim,; Clark Ajawani,; Suarez, Donald; Barnes, Thomas; Thomas Kulp,; Burgess, Matthew K.; Tseng, Iwen

    2015-01-01

    OBJECTIVES The purpose of this study was to determine the feasibility and sustainability of in-situ removal of arsenic from water infiltrated through unsaturated alluvium. BACKGROUND Arsenic is naturally present in aquifers throughout the southwestern United States and elsewhere. In January 2006, the U.S. Environmental Protection Agency (EPA) lowered the Maximum Contaminant Level (MCL) for arsenic from 50 to 10 micrograms per liter (g/L). This raised concerns about naturally-occurring arsenic in groundwater. Although commercially available systems using sorbent iron or aluminum oxide resins are available to treat high-arsenic water, these systems are expensive to build and operate, and may generate hazardous waste. Iron and aluminum oxides occur naturally on the surfaces of mineral grains that compose alluvial aquifers. In areas where alluvial deposits are unsaturated, these oxides may sorb arsenic in the same manner as commercial resins, potentially providing an effective low-cost alternative to commercially engineered treatment systems. APPROACH The Antelope Valley within the Mojave Desert of southern California contains a shallow water-table aquifer with arsenic concentrations of 5 g/L, and a deeper aquifer with arsenic concentrations of 30 g/L. Water was pumped from the deep aquifer into a pond and infiltrated through an 80 m-thick unsaturated zone as part of field-scale and laboratory experiments to treat high-arsenic groundwater and recharge the shallow water table aquifer at the site. The field-scale recharge experiment included the following steps: 1) construction of a recharge pond 2) test drilling for sample collection and instrument installation adjacent to the pond 3) monitoring downward migration of water infiltrated from the pond 4) monitoring changes in selected trace-element concentrations as water infiltrated through the unsaturated zone Data from instruments within the borehole adjacent to the pond were supplemented with borehole and

  3. Arsenic contamination in shallow groundwater and agricultural soil of Chakdaha Block, West Bengal, India

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    Anamika eShrivastava

    2014-11-01

    Full Text Available The study area comes in one of the eight districts of West Bengal where groundwater contains arsenic above the prescribed limit by WHO (10μg/l. Each day groundwater is being withdrawn by the village people for the fulfillment of their basic needs and for agricultural purposes. With the groundwater along with high concentration of arsenic (As, many other heavy metals are also getting introduced in the environment. In the areas with a long history of use of such groundwater, the agricultural lands have been affected severely. The extent of contamination has increased to a level where the crops grown in those lands are becoming a major source for arsenic and other heavy metals poisoning and subsequently transfer to different trophic levels. Based on this concern a somewhat detailed study was carried out to obtain an idea about the magnitude of soil and water contamination in the area. The mean concentrations (mg/kg of As (9.67, Fe (9275.58, Mn (190.04, Cu (26.53 and Zn (36.04 in the control land soils were found within the normal range. Whereas the mean As (54.40, Fe (15745.50, Mn (307.90, Cu (69.33 and Zn (44.56 were found to be in higher, mainly arsenic which is at an alarming point. In case of water samples, the pond water was having the mean concentration (μg/l of As (32.63, Fe (57.21, Mn (30.25, Cu (0.82. Whereas in case of shallow groundwater there was more increase in the case of As (76.43, Fe (5493.22, Mn (253.63, and Cu (1.825. It was also observed that Zn although present in soil samples, it was below detection limits in case of water samples. The As concentration in soil and water showed a positive correlation. Also the correlation analyses between soil arsenic and other heavy metals shows a positive co-relation with all of them.

  4. Spatial pattern of groundwater arsenic occurrence and association with bedrock geology in greater augusta, maine

    Science.gov (United States)

    Yang, Q.; Jung, H.B.; Culbertson, C.W.; Marvinney, R.G.; Loiselle, M.C.; Locke, D.B.; Cheek, H.; Thibodeau, H.; Zheng, Yen

    2009-01-01

    In New England, groundwater arsenic occurrence has been linked to bedrock geology on regional scales. To ascertain and quantify this linkage at intermediate (100-101 km) scales, 790 groundwater samples from fractured bedrock aquifers in the greater Augusta, Maine area are analyzed, and 31% of the sampled wells have arsenic concentrations >10 ??g/L. The probability of [As] exceeding 10 ??g/L mapped by indicator kriging is highest in Silurian pelite-sandstone and pelite-limestone units (???40%). This probability differs significantly (p 10 ??g/L arsenic in groundwater. ?? 2009 American Chemical Society.

  5. High-fluoride groundwater.

    Science.gov (United States)

    Rao, N Subba

    2011-05-01

    Fluoride (F(-)) is essential for normal bone growth, but its higher concentration in the drinking water poses great health problems and fluorosis is common in many parts of India. The present paper deals with the aim of establishment of facts of the chemical characteristics responsible for the higher concentration of F(-) in the groundwater, after understanding the chemical behavior of F(-) in relation to pH, total alkalinity (TA), total hardness (TH), carbonate hardness (CH), non-carbonate hardness (NCH), and excess alkalinity (EA) in the groundwater observed from the known areas of endemic fluorosis zones of Andhra Pradesh that have abundant sources of F(-)-bearing minerals of the Precambrians. The chemical data of the groundwater shows that the pH increases with increase F(-); the concentration of TH is more than the concentration of TA at low F(-) groundwater, the resulting water is represented by NCH; the TH has less concentration compared to TA at high F(-) groundwater, causing the water that is characterized by EA; and the water of both low and high concentrations of F(-) has CH. As a result, the F(-) has a positive relation with pH and TA, and a negative relation with TH. The operating mechanism derived from these observations is that the F(-) is released from the source into the groundwater by geochemical reactions and that the groundwater in its flowpath is subjected to evapotranspiration due to the influence of dry climate, which accelerates a precipitation of CaCO(3) and a reduction of TH, and thereby a dissolution of F(-). Furthermore, the EA in the water activates the alkalinity in the areas of alkaline soils, leading to enrichment of F(-). Therefore, the alkaline condition, with high pH and EA, and low TH, is a more conducive environment for the higher concentration of F(-) in the groundwater.

  6. Multiple inorganic toxic substances contaminating the groundwater of Myingyan Township, Myanmar: arsenic, manganese, fluoride, iron, and uranium.

    Science.gov (United States)

    Bacquart, Thomas; Frisbie, Seth; Mitchell, Erika; Grigg, Laurie; Cole, Christopher; Small, Colleen; Sarkar, Bibudhendra

    2015-06-01

    In South Asia, the technological and societal shift from drinking surface water to groundwater has resulted in a great reduction of acute diseases due to water borne pathogens. However, arsenic and other naturally occurring inorganic toxic substances present in groundwater in the region have been linked to a variety of chronic diseases, including cancers, heart disease, and neurological problems. Due to the highly specific symptoms of chronic arsenic poisoning, arsenic was the first inorganic toxic substance to be noticed at unsafe levels in the groundwater of West Bengal, India and Bangladesh. Subsequently, other inorganic toxic substances, including manganese, uranium, and fluoride have been found at unsafe levels in groundwater in South Asia. While numerous drinking water wells throughout Myanmar have been tested for arsenic, relatively little is known about the concentrations of other inorganic toxic substances in Myanmar groundwater. In this study, we analyzed samples from 18 drinking water wells (12 in Myingyan City and 6 in nearby Tha Pyay Thar Village) and 2 locations in the Ayeyarwaddy River for arsenic, boron, barium, beryllium, cadmium, cobalt, chromium, copper, fluoride, iron, mercury, manganese, molybdenum, nickel, lead, antimony, selenium, thallium, uranium, vanadium, and zinc. Concentrations of arsenic, manganese, fluoride, iron, or uranium exceeded health-based reference values in most wells. In addition, any given well usually contained more than one toxic substance at unsafe concentrations. While water testing and well sharing could reduce health risks, none of the wells sampled provide water that is entirely safe with respect to inorganic toxic substances. It is imperative that users of these wells, and users of other wells that have not been tested for multiple inorganic toxic substances throughout the region, be informed of the need for drinking water testing and the health consequences of drinking water contaminated with inorganic toxic

  7. Arsenic Removal from Natural Groundwater by Electrocoagulation Using Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    A. M. García-Lara

    2014-01-01

    Full Text Available Contamination of natural groundwater by arsenic (As is a serious problem that appears in some areas of Northern Central Mexico (NCM. In this research, As was removed from NCM wells groundwater by the electrocoagulation (EC technique. Laboratory-scale arsenic electroremoval experiments were carried out at continuous flow rates between 0.25 and 1.00 L min−1 using current densities of 5, 10, and 20 A m−2. Experiments were performed under galvanostatic conditions during 5 min, at constant temperature and pH. The response surface methodology (RSM was used for the optimization of the processing variables (flow rate and current density, response modeling, and predictions. The highest arsenic removal efficiency from underground water (99% was achieved at low flow rates (0.25 L min−1 and high current densities (20 A m−2. The response models developed explained 93.7% variability for As removal efficiency.

  8. Prediction of Groundwater Arsenic Contamination using Geographic Information System and Artificial Neural Network

    OpenAIRE

    Md. Moqbul Hossain; Krishna Neaupane; Nitin Kumar Tripathi; Mongkut Piantanakulchai

    2013-01-01

    Ground water arsenic contamination is a well known health and environmental problem in Bangladesh. Sources of this heavy metal are known to be geogenic, however, the processes of its release into groundwater are poorly understood phenomena. In quest of mitigation of the problem it is necessary to predict probable contamination before it causes any damage to human health. Hence our research has been carried out to find the factor relations of arsenic contamination and develop an arsenic contam...

  9. A review of arsenic and its impacts in groundwater of the Ganges-Brahmaputra-Meghna delta, Bangladesh.

    Science.gov (United States)

    Edmunds, W M; Ahmed, K M; Whitehead, P G

    2015-06-01

    Arsenic in drinking water is the single most important environmental issue facing Bangladesh; between 35 and 77 million of its 156 million inhabitants are considered to be at risk from drinking As-contaminated water. This dominates the list of stress factors affecting health, livelihoods and the ecosystem of the delta region. There is a vast literature on the subject so this review provides a filter of the more important information available on the topic. The arsenic problem arises from the move in the 1980s and 1990s by international agencies to construct tube wells as a source of water free of pathogens, groundwater usually considered a safe source. Since arsenic was not measured during routine chemical analysis and also is difficult to measure at low concentrations it was not until the late 1990s that the widespread natural anomaly of high arsenic was discovered and confirmed. The problem was exacerbated by the fact that the medical evidence of arsenicosis only appears slowly. The problem arises in delta regions because of the young age of the sediments deposited by the GBM river system. The sediments contain minerals such as biotite which undergo slow "diagenetic" reactions as the sediments become compacted, and which, under the reducing conditions of the groundwater, release in the form of toxic As(3+). The problem is restricted to sediments of Holocene age and groundwater of a certain depth (mainly 30-150 m), coinciding with the optimum well depth. The problem is most serious in a belt across southern Bangladesh, but within 50 m of the coast the problem is only minor because of use of deep groundwater; salinity in shallow groundwater here is the main issue for drinking water. The Government of Bangladesh adopted a National Arsenic Policy and Mitigation Action Plan in 2004 for providing arsenic safe water to all the exposed population, to provide medical care for those who have visible symptoms of arsenicosis. There is as yet no national monitoring program in

  10. Groundwater arsenic contamination from parts of the Ghaghara Basin, India: influence of fluvial geomorphology and Quaternary morphostratigraphy

    Science.gov (United States)

    Shah, Babar Ali

    2016-09-01

    A groundwater arsenic (As) distribution in Faizabad, Gonda, and Basti districts of Uttar Pradesh is shown in the entrenched channels and floodplains of the Ghaghara River. Tubewell water samples were analysed for As through flow injection hydride generation atomic absorption spectrometry (FI-HG-AAS) system. About 38, 61, and 42 % of tubewells in Faizabad, Gonda, and Basti districts, respectively, have As >10 µg/l (WHO guideline). Moreover, 15, 45, and 26 % of tubewells in Faizabad, Gonda, and Basti districts, respectively, have As above 50 µg/l. About 86, 69, and 35 % of tubewells in Faizabad, Gonda, and Basti districts, respectively, are from shallow depth (21-45 m), and it is worth noticing that 47 % As-contaminated (As >10 µg/l) tubewells in these three districts are located within the depth of 10-35 m in Holocene Newer Alluvium aquifers. The high content of As (7.11 mg/kg) is measured in suspended river sediments of the Ghaghara River. Most of the As-contaminated villages in the Ghaghara Basin are located close to abandoned or present meander channels and floodplains of the Ghaghara River. In contrast, tubewells in Faizabad, Ayodhya, and Nawabganj towns are As-safe because of their positions on the Pleistocene Older Alluvium upland surfaces. Quaternary geomorphology plays an important role in groundwater arsenic contamination in the Ghaghara Basin. The sources of groundwater arsenic are geogenic and perennial mountainous rivers in the Ghaghara Basin supplied high sediment loads. The arsenic in groundwater of Ghaghara Basin is getting released from associated sediments which were likely deposited from the Himalayas. The process of release of groundwater arsenic is reductive dissolution of iron hydroxides.

  11. Groundwater arsenic contamination from parts of the Ghaghara Basin, India: influence of fluvial geomorphology and Quaternary morphostratigraphy

    Science.gov (United States)

    Shah, Babar Ali

    2017-09-01

    A groundwater arsenic (As) distribution in Faizabad, Gonda, and Basti districts of Uttar Pradesh is shown in the entrenched channels and floodplains of the Ghaghara River. Tubewell water samples were analysed for As through flow injection hydride generation atomic absorption spectrometry (FI-HG-AAS) system. About 38, 61, and 42 % of tubewells in Faizabad, Gonda, and Basti districts, respectively, have As >10 µg/l (WHO guideline). Moreover, 15, 45, and 26 % of tubewells in Faizabad, Gonda, and Basti districts, respectively, have As above 50 µg/l. About 86, 69, and 35 % of tubewells in Faizabad, Gonda, and Basti districts, respectively, are from shallow depth (21-45 m), and it is worth noticing that 47 % As-contaminated (As >10 µg/l) tubewells in these three districts are located within the depth of 10-35 m in Holocene Newer Alluvium aquifers. The high content of As (7.11 mg/kg) is measured in suspended river sediments of the Ghaghara River. Most of the As-contaminated villages in the Ghaghara Basin are located close to abandoned or present meander channels and floodplains of the Ghaghara River. In contrast, tubewells in Faizabad, Ayodhya, and Nawabganj towns are As-safe because of their positions on the Pleistocene Older Alluvium upland surfaces. Quaternary geomorphology plays an important role in groundwater arsenic contamination in the Ghaghara Basin. The sources of groundwater arsenic are geogenic and perennial mountainous rivers in the Ghaghara Basin supplied high sediment loads. The arsenic in groundwater of Ghaghara Basin is getting released from associated sediments which were likely deposited from the Himalayas. The process of release of groundwater arsenic is reductive dissolution of iron hydroxides.

  12. Groundwater arsenic contamination in one of the 107 arsenic-affected blocks in West Bengal, India: Status, distribution, health effects and factors responsible for arsenic poisoning.

    Science.gov (United States)

    Roychowdhury, Tarit

    2010-11-01

    A somewhat detailed study was carried out in Gaighata, one of the 107 arsenic-affected blocks in West Bengal, India, to determine the degree of groundwater contamination with arsenic, its depth wise distribution, correlation with iron, arsenical health effects to the inhabitants and the factors responsible for arsenic poisoning. Groundwater in all the 107 mouzas over 13 gram-panchayets in Gaighata block contains arsenic above 0.01mgl(-1) and in 91 mouzas, arsenic concentration has been found above 0.05mgl(-1). About 59.2 and 40.3% of the tubewell water samples contain arsenic above 0.01 and 0.05mgl(-1), respectively. The approximate population drinking arsenic-contaminated water above 0.01 and 0.05mgl(-1) are 106,560 and 72,540, respectively. The tubewells that were installed within the depth range of 15.4-30.3m are mostly arsenic-contaminated. Even the shallow groundwater level (7.87-15.1m) is arsenic-contaminated. Both arsenic and iron concentrations in groundwater gradually increase from lower depth to higher depth up to 39.4m, and then decrease with increasing depth. About 58% of the deep tubewell water samples (depth range 122-182m, n=31) contain arsenic ≥0.05mgl(-1). About 72% of the arsenic-contaminated deep tubewells (n=18) were safe when surveyed first time. But within a span of 2-5 years, they became contaminated with arsenic. The linear regression shows direct correlation between arsenic and iron concentrations in groundwater (r(2)=0.8114, parsenic from water by an adult male and female in the surveyed areas are 11.7 and 13.1μg/kg body wt./day, respectively and these values are higher than the WHO recommended PTDI value of inorganic arsenic (2.1μg/kg body wt./day). Mean arsenic concentrations in urine, hair and nail samples, collected from the inhabitants of Gutri mouza are higher than their normal level and the values are 292μgl(-1) (range: 8.35-1024μg l(-1), n=193), 2.50mgkg(-1) (range: 0.17-5.99mgkg(-1), n=132), and 6.05mgkg(-1) (range: 0

  13. Enhancing arsenic removal from groundwater at household level with naturally occurring iron

    Directory of Open Access Journals (Sweden)

    Anitha Kumari Sharma

    2016-06-01

    Full Text Available A supply of drinking water low in Arsenic (As prevents arsenic poisoning. The presence of high concentrations of iron (Fe in groundwater under the alluvial plains of the large rivers in Southeast Asia is a prerequisite for the simple removal of As. This study investigated the mechanisms and possibilities for enhancing As removal with naturally occurring Fe in a reliable, low cost and sustainable way. The results of the study show that As removal with Fe is greatly enhanced by the addition of an oxidizing agent (preferably KMnO4 immediately after the pumping of groundwater. Further enhancement of As removal in the presence of Fe can be achieved by adding a small volume of a concentrated basic solution of MnO4- and AlO2-, which has a combined oxidation, coagulation and buffering capacity. Best results were obtained when this solution was mixed with the groundwater immediately after its pumping until a pale pink color appeared. Maximum required reaction time was 10 minutes and subsequent filtration of the water was able to reduce the As concentration to near zero. Concentrations of MnO4- and AlO2- can be varied in the solution to achieve sufficient As removal to suit different Fe/As ratios and the presence of interfering co-occurring anions.

  14. Geogenic fluoride and arsenic contamination in the groundwater environments in Tanzania

    Science.gov (United States)

    Bhattacharya, Prosun; Lesafi, Fina; Filemon, Regina; Ligate, Fanuel; Ijumulana, Julian; Mtalo, Felix

    2016-04-01

    Adequate, safe and accessible drinking water is an important aspect to human health worldwide. Understanding this importance, the Tanzanian Government has initiated a number of programmes to ensure access to high quality water by the citizens. However, elevated concentration of geochemical pollutants in many drinking water sources pose a serious challenge to water suppliers and users in the country. Fluoride is a widespread drinking water contaminant of geogenic origin occuring in both surface- and groundwater around volcanic mountains and many parts within the East African Rift Valley in regions including Arusha (10 mg/L), Shinyanga (2.9 mg/L) and Singida (1.8 mg/L). An estimated 90% of the population living along the Rift Valley region are affected by dental or skeletal fluorosis and bone crippling because of long term exposure to very high levels of fluoride in drinking water sources. In the mining areas within Lake Victoria basin, groundwater wit elevated concentrations of arsenic has been discovered over an extended area. Most of these geochemical and naturally occurring drinking water pollutants are patchy with uncertainities in their spatial and temporal distribution patterns. The adverse health effects of skin disorder and cancer due to an elevated As concentration are reported from the North Mara gold and Geita mining areas in the Lake Victoria basin. About 30% of the water sources used for drinking in Tanzania exceed the WHO guideline values of fluoride (1.5 mg/L) and arsenic (10 μg/L). There is a scarcity of baseline information on the water quality data especially on geogenic contaminants in the groundwater and surface water as potable sources. This information is crucial in exploring sources of safe drinking water aquifers, associated human health risks of fluoride and arsenic pollution. using Laboratory based studies during the past two decades have shown promising results on the removal of fluoride and arsenic using locally available adsorbent

  15. Evaluation of Groundwater for Arsenic Contamination Using Hydrogeochemical Properties and Multivariate Statistical Methods in Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Abdullah S. Al-Farraj

    2013-01-01

    Full Text Available The aim of this research is to evaluate arsenic distribution and associated hydrogeochemical parameters in 27 randomly selected boreholes representing aquifers in the Al-Kharj geothermal fields of Saudi Arabia. Arsenic was detected at all sites, with 92.5% of boreholes yielding concentrations above the WHO permissible limit of 10 μg/L. The maximum concentration recorded was 122 μg/L (SD = 29 μg/L skewness = 1.87. The groundwater types were mainly Ca+2-Mg+2-SO4-2-Cl− and Na+-Cl−-SO4-2, accounting for 67% of the total composition. Principal component analysis (PCA showed that the main source of arsenic release was geothermal in nature and was linked to processes similar to those involved in the release of boron. The PCA yielded five components, which accounted for 44.1%, 17.0%, 10.1%, 08.4%, and 06.5% of the total variance. The first component had positive loadings for arsenic and boron along with other hydrogeochemical parameters, indicating the primary sources of As mobilization are derived from regional geothermal systems and weathering of minerals. The remaining principal components indicated reductive dissolution of iron oxyhydroxides as a possible mechanism. Spatial evaluation of the PCA results indicated that this secondary mechanism of arsenic mobilization may be active and correlates positively with total organic carbon. The aquifers were found to be contaminated to a high degree with organic carbon ranging from 0.57 mg/L to 21.42 mg/L and showed high concentrations of NO3- ranging from 8.05 mg/L to 248.2 mg/L.

  16. Characteristics and role of groundwater dissolved organic matter on arsenic mobilization and poisoning in Bangladesh

    Science.gov (United States)

    Tareq, Shafi M.; Maruo, Masahiro; Ohta, Keiichi

    The fluorescence and molecular weight characteristics of dissolved organic matter (DOM) in groundwater of Bangladesh were investigated to evaluate its multiple roles on arsenic (As) mobilization and poisoning. Fluorescence properties of DOM were measured in groundwater samples collected from two As contaminated areas of Bangladesh (Faridpur at the Ganges floodplain and Sonargaon at the Meghna floodplain) from different locations and depths. The three dimensional excitation-emission matrix (3DEEM) fluorescence spectra of groundwater samples showed two characteristic peaks around Ex/Em = 335-365 nm/435-480 nm for fulvic-like peaks and peak at around Ex/Em = 275-290 nm/310-335 nm for the protein-like materials. The similarity of fluorescence spectra of groundwater and surface water of both the study areas with high intensity of fluorescence and its strong correlation with DOC reflect the in situ generation of fluorescent DOM from sedimentary organic matter (SOM) and recent recharge of terrestrial labile organic carbon into shallow aquifer. High performance size-exclusion chromatography (HPSEC) analysis of DOM shows positive correlations between fluorescence intensities (FI) of small molecular fractions (0.65 kDa) and As concentrations, with the signatures of protein-like peaks of DOM in groundwater. This result provides new evidence that small molecular weight fraction of DOM in groundwater of Bangladesh can play an important role on As mobilization and toxicity. In addition, high concentration of fluorescence materials in DOM of As contaminated groundwater of Bangladesh may pose a threat to public health.

  17. Multiple inorganic toxic substances contaminating the groundwater of Myingyan Township, Myanmar: Arsenic, manganese, fluoride, iron, and uranium

    Energy Technology Data Exchange (ETDEWEB)

    Bacquart, Thomas [Better Life Laboratories, Calais, VT (United States); Frisbie, Seth [Better Life Laboratories, Calais, VT (United States); Department of Chemistry and Biochemistry, Norwich University, Northfield, VT (United States); Mitchell, Erika [Better Life Laboratories, Calais, VT (United States); Grigg, Laurie [Department of Earth and Environmental Science, Norwich University, Northfield, VT (United States); Cole, Christopher [Department of Chemistry and Biochemistry, Norwich University, Northfield, VT (United States); Small, Colleen [Vermont Department of Health Laboratory, Burlington, VT (United States); Sarkar, Bibudhendra, E-mail: bsarkar@sickkids.ca [Department of Molecular Structure and Function, The Research Institute of The Hospital for Sick Children, University of Toronto, Toronto, Ontario (Canada); Department of Biochemistry, University of Toronto, Toronto, Ontario (Canada)

    2015-06-01

    In South Asia, the technological and societal shift from drinking surface water to groundwater has resulted in a great reduction of acute diseases due to water borne pathogens. However, arsenic and other naturally occurring inorganic toxic substances present in groundwater in the region have been linked to a variety of chronic diseases, including cancers, heart disease, and neurological problems. Due to the highly specific symptoms of chronic arsenic poisoning, arsenic was the first inorganic toxic substance to be noticed at unsafe levels in the groundwater of West Bengal, India and Bangladesh. Subsequently, other inorganic toxic substances, including manganese, uranium, and fluoride have been found at unsafe levels in groundwater in South Asia. While numerous drinking water wells throughout Myanmar have been tested for arsenic, relatively little is known about the concentrations of other inorganic toxic substances in Myanmar groundwater. In this study, we analyzed samples from 18 drinking water wells (12 in Myingyan City and 6 in nearby Tha Pyay Thar Village) and 2 locations in the Ayeyarwaddy River for arsenic, boron, barium, beryllium, cadmium, cobalt, chromium, copper, fluoride, iron, mercury, manganese, molybdenum, nickel, lead, antimony, selenium, thallium, uranium, vanadium, and zinc. Concentrations of arsenic, manganese, fluoride, iron, or uranium exceeded health-based reference values in most wells. In addition, any given well usually contained more than one toxic substance at unsafe concentrations. While water testing and well sharing could reduce health risks, none of the wells sampled provide water that is entirely safe with respect to inorganic toxic substances. It is imperative that users of these wells, and users of other wells that have not been tested for multiple inorganic toxic substances throughout the region, be informed of the need for drinking water testing and the health consequences of drinking water contaminated with inorganic toxic

  18. Prediction of contamination potential of groundwater arsenic in Cambodia, Laos, and Thailand using artificial neural network

    Science.gov (United States)

    The arsenic (As) contamination of groundwater has increasingly been recognized as a major global issue of concern. As groundwater resources are one of most important freshwater sources for water supplies in Southeast Asian countries, it is important to investigate the spatial distribution of As cont...

  19. Health risk assessment of groundwater arsenic pollution in southern Taiwan.

    Science.gov (United States)

    Liang, Ching-Ping; Wang, Sheng-Wei; Kao, Yu-Hsuan; Chen, Jui-Sheng

    2016-12-01

    Residents of the Pingtung Plain, Taiwan, use groundwater for drinking. However, monitoring results showed that a considerable portion of groundwater has an As concentration higher than the safe drinking water regulation of 10 μg/L. Considering residents of the Pingtung Plain continue to use groundwater for drinking, this study attempted to evaluate the exposure and health risk from drinking groundwater. The health risk from drinking groundwater was evaluated based on the hazard quotient (HQ) and target risk (TR) established by the US Environmental Protection Agency. The results showed that the 95th percentile of HQ exceeded 1 and TR was above the safe value of threshold value of 10(-6). To illustrate significant variability of the drinking water consumption rate and body weight of each individual, health risk assessments were also performed using a spectrum of daily water intake rate and body weight to reasonably and conservatively assess the exposure and health risk for the specific subgroups of population of the Pingtung Plain. The assessment results showed that 0.01-7.50 % of the population's HQ levels are higher than 1 and as much as 77.7-93.3 % of the population being in high cancer risk category and having a TR value >10(-6). The TR estimation results implied that groundwater use for drinking purpose places people at risk of As exposure. The government must make great efforts to provide safe drinking water for residents of the Pingtung Plain.

  20. Mathematical model to predict the transport of dissolved arsenic in groundwater influenced by seepage velocity

    Directory of Open Access Journals (Sweden)

    Solomon Ndubuisi Eluozo

    2012-11-01

    Full Text Available Development of mathematical model to predict the transport of dissolved arsenic in groundwater influenced by seepage velocity has been carried out. This model was developed to monitor the rate of concentration at different period and depths. High and low concentrations were observed at different periods and depth as presented in the figures. These conditions can be attributed to soil stratification deposition in the study location and the influence of man-made activities. Based on these facts, it is recommended that risk assessment should be thoroughly done for soil and water and the predicted model should be applied in design and construction of groundwater system in the study area. 

  1. Association between arsenic and different-sized dissolved organic matter in the groundwater of black-foot disease area, Taiwan.

    Science.gov (United States)

    Chen, Ting-Chien; Hseu, Zeng-Yei; Jean, Jiin-Shuh; Chou, Mon-Lin

    2016-09-01

    The formation of an arsenic (As)-dissolved organic matter (DOM) complex is important in driving the release of arsenic in groundwater. This study collected groundwater samples from a 20 m deep well throughout 2014 and separated each into three subsamples by ultrafiltration: high molecular weight-DOM (HDOM, 0.45 μm-10 kDa), medium molecular weight-DOM (MDOM, 10-1 kDa), and low molecular weight-DOM (LDOM, arsenic and the fractional DOM. Based on the EEM records, three fluorescence indicators were further calculated to characterize the DOM sources, including the fluorescence index (FI), the biological index (BI), and the humification index (HI). The experimental results indicated that arsenic in the groundwater was mainly partitioned into the MDOM and LDOM fractions. All fractional DOMs contained humic acid-like substances and were considered as microbial sources. LDOM had the highest humification degree and aromaticity, followed by MDOM and HDOM. The As and DOM association could be formed by a Fe-bridge, which was demonstrated by the Ks values and fourier transform infrared (FTIR) spectra of the DOM. The formation of AsFe-DOM complex was only significant in the MDOM and LDOM.

  2. OCCURRENCE OF ARSENIC, LEAD, THALLIUM AND BERYLLIUM IN GROUNDWATER

    Directory of Open Access Journals (Sweden)

    Abdul A.J. Mohamed

    2014-01-01

    Full Text Available The occurrence of carcinogenic and heavy metals in groundwater sources in Urban-west region of Zanzibar Island is an issue that is not very well known. This could be also coupled with the absence of drinking water treatment plants. This study for the first time reports on the occurrence and the levels of three carcinogenic metals-Arsenic (As, Beryllium (Be and lead (Pb in thirty groundwater samples collected from Zanzibar’s Urban/West region. The levels of alkalinity, Magnesium (Mg and Thallium (Tl were also determined. The concentrations of As, Be, TI and Pb in the water samples were determined by the Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES. Palintest photometry procedures were used to determine the levels of total alkalinity and magnesium. Be, As, Tl and Pb were not detected (nd in some water samples. The ranges of concentrations of Be, As, TI and Pb in the samples were; nd to 6100 ng L-1, nd to 6600 ng L-1, nd to 11600 ng L-1 and nd to 31400 ng L-1 respectively. The levels of total alkalinity varied from 38 to 380 (mg L-1 as CaCO3. The proportions of water samples contaminated with Be, Tl, As and Pb were 43.3, 66.7, 70 and 96.7% respectively. About 23% of the water samples had Pb concentrations beyond WHO limits for safe drinking water, while 30 and 56.67% of the samples had Be and Tl concentrations beyond the US EPA’s maximum limits. The concentration of arsenic in each water sample was within WHO limits. The occurrence and the levels of carcinogenic metals in water sources could be a potential cause of cancer cases in Zanzibar. Therefore, prompt action is required to control the levels of these hazardous metals, and other possible contaminants in Zanzibar’s domestic water systems.

  3. Can Homeopathic Arsenic Remedy Combat Arsenic Poisoning in Humans Exposed to Groundwater Arsenic Contamination?: A Preliminary Report on First Human Trial

    Directory of Open Access Journals (Sweden)

    Anisur Rahman Khuda-Bukhsh

    2005-01-01

    Full Text Available Groundwater arsenic (As has affected millions of people globally distributed over 20 countries. In parts of West Bengal (India and Bangladesh alone, over 100 million people are at risk, but supply of As-free water is grossly inadequate. Attempts to remove As by using orthodox medicines have mostly been unsuccessful. A potentized homeopathic remedy, Arsenicum Album-30, was administered to a group of As affected people and thereafter the As contents in their urine and blood were periodically determined. The activities of various toxicity marker enzymes and compounds in the blood, namely aspartate amino transferase, alanine amino transferase, acid phosphatase, alkaline phosphatase, lipid peroxidation and reduced glutathione, were also periodically monitored up to 3 months. The results are highly encouraging and suggest that the drug can alleviate As poisoning in humans.

  4. Effect of groundwater--lake interactions on arsenic enrichment in freshwater beach aquifers.

    Science.gov (United States)

    Lee, Jacky; Robinson, Clare; Couture, Raoul-Marie

    2014-09-02

    Field measurements combined with numerical simulations provide insight into the water exchange, groundwater flow, and geochemical processes controlling the mobility of arsenic (As) in freshwater beach aquifers. Elevated dissolved As (up to 56 μg/L) was observed 1-2 m below the shoreline at two sandy beaches on Lake Erie, Ontario, Canada. Water and solid-phase analyses suggest that Fe (hydr)oxides present below the shoreline accumulate As, creating a risk of high As in the beach aquifer. Groundwater flow simulations combined with vertical hydraulic gradient measurements indicate that wave-induced flow recirculations across the groundwater-lake interface are significant. These recirculations, which vary with wave intensity and lake water level fluctuations, set up redox and pH gradients, where Fe precipitates and subsequently sequesters As. The elevated As concentrations observed at both beaches, combined with the distribution of other dissolved species, suggest that the As enrichment may be naturally occurring. Regardless of the As source, the interacting hydrologic and geochemical processes revealed may have important implications for the flux of As and also other oxyanions, such as phosphate, across the groundwater-lake interface in nearshore areas of the Great Lakes.

  5. Removal of groundwater arsenic using a household filter with iron spikes and stainless steel.

    Science.gov (United States)

    Avilés, M; Garrido, S E; Esteller, M V; De la Paz, J S; Najera, C; Cortés, J

    2013-12-15

    Arsenic (As) in groundwater for domestic use poses a worldwide threat to public health, most notably in rural areas. The aims of this study were: first, determine groundwater composition in a mining area in central Mexico (Huautla); second, assess As exposure through human groundwater consumption and; third, develop and test a household filter to obtain drinking water for these rural communities. From the 17th century through the 1990s, mines in the area produced Ag-galena and sphalerite from volcanic rock. Groundwater flooded the mines when they were abandoned due to low silver prices. Local households now use the water to meet domestic needs. Water from the mines was found to have high As content (0.04-0.26 mg L(-1)) and Fe, Mn, Pb and Cd were also above Mexican drinking water standards and WHO guidelines. All the population in the Huautla community was exposed to the metalloid through water used in food preparation. The best As removal was obtained with a filter using oxidized commercial fiber (HCl 2N as oxidant). Concentrations in the effluent were below Mexican drinking water standards (0.025 mg As L(-1) water) during the 105-day (2520 h) filter operation, with a maximum As removal efficiency of 95.4%. The household filter was simple, low-cost and may be very attractive for As removal in rural areas in developing countries.

  6. Speciation and Source Identification for Arsenic in the Southern High Plains Aquifer

    Science.gov (United States)

    Venkataraman, K.; Rainwater, K.; Jackson, W. A.; Ridley, M. K.

    2009-12-01

    Significant levels of arsenic have been detected in the groundwater of the Southern High Plains. The potential sources include atmospheric deposition, the use of agricultural defoliants and natural subsurface geochemical interactions. To identify the source of arsenic, groundwater and soil samples were collected by the Texas Tech University Water Resources Center from sites spread over 18 counties in the West Texas region. Arsenic and its inorganic species were quantified along with commonly occurring and related cations and anions such as iron, manganese, copper and sulfate. Correlation studies were conducted to understand the variation of arsenical species with related parameters. A geochemical modeling tool, MINTEQ was used to predict the speciation of arsenic and compare these results with lab analyses. Sensitivity analysis was also conducted with MINTEQ to study the behavior of arsenical species with variations in total iron and field parameters such as pH, ORP, and DO. The distribution of arsenic and its species in the soil profiles tested indicated a positive correlation with depth. The highest concentrations were found close to the water table while the upper soil layers had low to non-detect concentrations. In the groundwater samples, arsenic concentration and speciation varied significantly between sites. As (III) was found to be the dominant species in the majority (>80%) of the samples. MINTEQ speciation forecasts compared favorably with a majority of the groundwater analyses. Sensitivity analyses indicated a negative correlation between As(III) and ORP, while increasing iron concentration increased the levels of As(III). Decreasing iron caused no significant change in the concentration of As(III). Low concentrations of arsenic in the shallow layers of the soil have led to the elimination of atmospheric deposition and the use of defoliants as potential sources of contamination. The combination of analytical results and the geochemical simulations

  7. Naturally occurring arsenic in groundwater and identification of the geochemical sources in the Duero Cenozoic Basin, Spain

    Science.gov (United States)

    Gómez, J. J.; Lillo, J.; Sahún, B.

    2006-09-01

    Arsenic concentrations surpassing potability limit of 10 μg/L in the groundwater supplies of an extensive area in the Duero Cenozoic Basin (central Spain) have been detected and the main sources of arsenic identified. Arsenic in 514 samples of groundwater, having mean values of 40.8 μg/L, is natural in origin. Geochemical analysis of 553 rock samples, assaying arsenic mean values of 23 mg/kg, was performed. Spatial coincidence between the arsenic anomaly in groundwater and the arsenic lithogeochemical distribution recorded in the Middle Miocene clayey organic-rich Zaratan facies illustrates that the rocks of this unit are the main source of arsenic in groundwater. The ferricretes associated to the Late Cretaceous-Middle Miocene siliciclastics also constitute a potential arsenic source. Mineralogical study has identified the presence of arsenic in iron oxides, authigenic pyrite, manganese oxides, inherited titanium-iron oxides, phyllosilicates and organomineral compounds. Arsenic mobilization to groundwater corresponds to arsenic desorption from iron and manganese oxides and from organic matter.

  8. Controls of paleochannels on groundwater arsenic distribution in shallow aquifers of alluvial plain in the Hetao Basin, China.

    Science.gov (United States)

    Cao, Wengeng; Guo, Huaming; Zhang, Yilong; Ma, Rong; Li, Yasong; Dong, Qiuyao; Li, Yuanjie; Zhao, Ruike

    2017-09-21

    Less is known about controls of sedimentary structures in groundwater As distributions in sedimentary aquifers, and quantitative description of relationship between sedimentary environment and high As groundwater (according to WHO, As>10μg/L) is a challenging issue. Three hundred and eighty-two hydrogeological borehole loggings (well depths of 50-300m) were collected and four hundred and ninety nine groundwater samples were taken to investigate controls of paleochannels on groundwater arsenic distribution in shallow aquifers of alluvial plain in the Hetao Basin. Results showed that the swing zone, formed by bursting, diversion and swing of ancient Yellow River course since the Late Pleistocene, has an obviously corresponding relationship with spatial variability of groundwater As in the Hetao Basin. "Swing Intensity Index" (S), which is firstly defined as the sum of clay-sand ratio (R) and the number of clay layers (N), can be used as the sedimentary facies symbol to establish the new recognition method for hosting high As groundwater. There is a positive correlation between the swing intensity index (S) of paleochannels and groundwater As concentrations. The swing zones of paleochannels with high S values represent hydrogeochemical characteristics of the strong reducing environment, serious evaporation, strong cation exchange, and the low infiltration recharge of surface water, which lead to enrichment of groundwater As in the shallow aquifers. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Comparison of the accuracy of kriging and IDW interpolations in estimating groundwater arsenic concentrations in Texas.

    Science.gov (United States)

    Gong, Gordon; Mattevada, Sravan; O'Bryant, Sid E

    2014-04-01

    Exposure to arsenic causes many diseases. Most Americans in rural areas use groundwater for drinking, which may contain arsenic above the currently allowable level, 10µg/L. It is cost-effective to estimate groundwater arsenic levels based on data from wells with known arsenic concentrations. We compared the accuracy of several commonly used interpolation methods in estimating arsenic concentrations in >8000 wells in Texas by the leave-one-out-cross-validation technique. Correlation coefficient between measured and estimated arsenic levels was greater with inverse distance weighted (IDW) than kriging Gaussian, kriging spherical or cokriging interpolations when analyzing data from wells in the entire Texas (p<0.0001). Correlation coefficient was significantly lower with cokriging than any other methods (p<0.006) for wells in Texas, east Texas or the Edwards aquifer. Correlation coefficient was significantly greater for wells in southwestern Texas Panhandle than in east Texas, and was higher for wells in Ogallala aquifer than in Edwards aquifer (p<0.0001) regardless of interpolation methods. In regression analysis, the best models are when well depth and/or elevation were entered into the model as covariates regardless of area/aquifer or interpolation methods, and models with IDW are better than kriging in any area/aquifer. In conclusion, the accuracy in estimating groundwater arsenic level depends on both interpolation methods and wells' geographic distributions and characteristics in Texas. Taking well depth and elevation into regression analysis as covariates significantly increases the accuracy in estimating groundwater arsenic level in Texas with IDW in particular.

  10. Risk assessment for arsenic-contaminated groundwater along River Indus in Pakistan.

    Science.gov (United States)

    Rabbani, Unaib; Mahar, Gohar; Siddique, Azhar; Fatmi, Zafar

    2017-02-01

    The study determined the risk zone and estimated the population at risk of adverse health effects for arsenic exposure along the bank of River Indus in Pakistan. A cross-sectional survey was conducted in 216 randomly selected villages of one of the districts along River Indus. Wells of ten households from each village were selected to measure arsenic levels. The location of wells was identified using global positioning system device, and spatial variations of the groundwater contamination were assessed using geographical information system tools. Using layers of contaminated drinking water wells according to arsenic levels and population with major landmarks, a risk zone and estimated population at risk were determined, which were exposed to arsenic level ≥10 µg/L. Drinking wells with arsenic levels of ≥10 µg/L were concentrated within 18 km near the river bank. Based on these estimates, a total of 13 million people were exposed to ≥10 µg/L arsenic concentration along the course of River Indus traversing through 27 districts in Pakistan. This information would help the researchers in designing health effect studies on arsenic and policy makers in allocating resources for designing focused interventions for arsenic mitigation in Pakistan. The study methods have implication on similar populations which are affected along rivers due to arsenic contamination.

  11. Ecosystem perspective of groundwater arsenic contamination in India and relevance in policy.

    Science.gov (United States)

    Sarkar, Atanu

    2010-08-01

    Millions of people living in India are at risk by consuming arsenic contaminated groundwater. Several technological solutions have failed to address the problem due to segmental approaches, resulting in human suffering for a period of three decades. The article is based on an analysis of arsenic-related health problems from an ecosystem perspective through a primary survey conducted in five arsenic affected villages in the state of West Bengal and review of existing research and policy documents. Although modern agricultural practices and drinking water policies have resulted in arsenic contamination of groundwater, current mitigation policy is essentially confined to biomedical approaches, which includes potable water supply and medical care. The study also shows that existing disparity, difficulty in coping, inaccessibility to health service and potable water supply and lack of participation in decision making have resulted in more suffering among the poor. On the other hand, spreading of arsenic contamination in the ecosystem remains unabated. Foods grown in the affected area have emerged as additional sources of exposure to humans. There is lack of evidence of any perceivable benefits due to sustainable agriculture, as present nature of agriculture practice is essentially driven by crop yield only. Further research is needed to generate credible evidence of alternative agriculture paradigms that may eventually reduce body burden of arsenic through reduced dependency on groundwater.

  12. Transformation and removal of arsenic in groundwater by sequential anodic oxidation and electrocoagulation

    Science.gov (United States)

    Zhang, Peng; Tong, Man; Yuan, Songhu; Liao, Peng

    2014-08-01

    Oxidation of As(III) to As(V) is generally essential for the efficient remediation of As(III)-contaminated groundwater. The performance and mechanisms of As(III) oxidation by an as-synthesized active anode, SnO2 loaded onto Ti-based TiO2 nanotubes (Ti/TiO2NTs/Sb-SnO2), were investigated. The subsequent removal of total arsenic by electrocoagulation (EC) was further tested. The Ti/TiO2NTs/Sb-SnO2 anode showed a high and lasting electrochemical activity for As(III) oxidation. 6.67 μM As(III) in synthetic groundwater was completely oxidized to As(V) within 60 min at 50 mA. Direct electron transfer was mainly responsible at the current below 30 mA, while hydroxyl radicals contributed increasingly with the increase in the current above 30 mA. As(III) oxidation was moderately inhibited by the presence of bicarbonate (20 mM), while was dramatically increased with increasing the concentration of chloride (0-10 mM). After the complete oxidation of As(III) to As(V), total arsenic was efficiently removed by EC in the same reactor by reversing electrode polarity. The removal efficiency increased with increasing the current but decreased by the presence of phosphate and silica. Anodic oxidation represents an effective pretreatment approach to increasing EC removal of As(III) in groundwater under O2-limited conditions.

  13. Vinegar-amended anaerobic biosand filter for the removal of arsenic and nitrate from groundwater.

    Science.gov (United States)

    Snyder, Kathryn V; Webster, Tara M; Upadhyaya, Giridhar; Hayes, Kim F; Raskin, Lutgarde

    2016-04-15

    The performance of a vinegar-amended anaerobic biosand filter was evaluated for future application as point-of-use water treatment in rural areas for the removal of arsenic and nitrate from groundwater containing common ions. Due to the importance of sulfate and iron in arsenic removal and their variable concentrations in groundwater, influent sulfate and iron concentrations were varied. Complete removal of influent nitrate (50 mg/L) and over 50% removal of influent arsenic (200 μg/L) occurred. Of all conditions tested, the lowest median effluent arsenic concentration was 88 μg/L. Iron removal occurred completely when 4 mg/L was added, and sulfate concentrations were lowered to a median concentration removal and the establishment of reducing conditions, arsenic concentrations remained above the World Health Organization's arsenic drinking water standard. Further research is necessary to determine if anaerobic biosand filters can be improved to meet the arsenic drinking water standard and to evaluate practical implementation challenges.

  14. Stratigraphic Evolution of the Ganges-Brahmaputra Lower Delta Plain and its Relation to Groundwater Arsenic Distributions

    Science.gov (United States)

    Patrick, M. G.; Goodbred, S. L., Jr.; Gilligan, J. M.; Tasich, C. M.; Hossain, S.; Ahmed, K. M.

    2015-12-01

    Bangladesh is plagued by high concentrations of naturally occurring arsenic (As) in the shallow groundwater of the Ganges-Brahmaputra-Meghna delta (GBMD), leading to widespread poisoning of people in the region. Most of the 156 million people in Bangladesh obtain their drinking water through hand-pumped tube wells that often draw arsenic-contaminated water from shallow, Holocene-age aquifers of the delta. The distribution of arsenic within these aquifers is heterogeneous and linked with the complex stratigraphy of the GBMD through its controls on hydrogeology and aquifer biogeochemistry. This research investigates differences in the fluvio-deltaic deposits formed by the Ganges and Brahmaputra rivers, as well as differences in the tectonic setting across the lower delta plain. Furthermore, we investigate how these overarching controls influence stratigraphic architecture and the resulting aquifer systems, and ultimately the distribution of As within the shallow aquifers of the lower delta plain. To accomplish this, a transect of 55 sediment cores spanning the entire lower delta plain of Bangladesh was drilled to a depth of 90 m. In addition to knowledge of the stratigraphic architecture gained from borehole lithologs, samples from these cores were analyzed for provenance and grain size to determine source of the sediments and the depositional history of the rivers. Relating delta stratigraphy to As distribution was accomplished by measuring groundwater As in 10-20 tubewells within a 1 km radius of each borehole. This data was combined with groundwater data from the Bangladesh Arsenic Mitigation Water Supply Project within 25 km of the transect. Statistical analysis of the groundwater data was then conducted using hierarchical regressions as well as a nearest neighbor algorithm. This study provides a better understanding of Holocene delta evolution and river behavior, as well as a more complete understanding of the geologic controls on As and the characteristics of

  15. Phosphate-Based Mineralization of Arsenic in Contaminated Soil: A Potential Remediation Method for Soil and Groundwater

    Science.gov (United States)

    Neupane, G.; Donahoe, R. J.

    2009-12-01

    Soil arsenic contamination resulting from the use of arsenical compounds is a widespread environmental problem. A phosphate-based remediation method which has the potential to immobilize arsenic in both oxidizing and reducing subsurface systems is under laboratory investigation. Although phosphate treatments have been reported to be effective in removal of arsenic from contaminated water, its use in contaminated soils has not been tested. This study aims to (1) determine the competitive adsorption/desorption of arsenate and phosphate at surfaces of ferric hydroxide coated sand in the absence or presence of calcium ions, and (2) develop a method of arsenic fixation which involves phosphoric acid flushing of arsenic from contaminated soil and precipitation of arsenic as apatite-like phases. Ferric hydroxide is a significant arsenic sequestering constituent in soil. Phosphate competes with arsenate for adsorption sites on the ferric hydroxide surface. Batch adsorption experiments conducted using ferric hydroxide coated sand have indicated similar pH-controlled adsorption mechanisms for both arsenate and phosphate. The data obtained from the adsorption experiments is being used to guide the development of a phosphate-based method for soil and groundwater arsenic remediation. Batch experiments were performed using 3g of contaminated soil in contact with 45 ml of treatment fluid (a dilute phosphoric acid and calcium hydroxide solution). Solution samples were collected at 24, 72, 144, 312, and 384 hours, with continuous agitation at 200 rpm. Solution concentrations of phosphorus and calcium generally decreased with time and were primarily controlled by pH. It has been experimentally demonstrated that solution arsenic concentrations can be lowered by maintaining high pH with adequate calcium supply. A batch experiment conducted at pH > 11, using 1 kg of soil in contact with 1 liter of 0.25% H3PO4, precipitated a white material giving an XRD signature indicative of brushite

  16. High fat diet aggravates arsenic induced oxidative stress in rat heart and liver.

    Science.gov (United States)

    Dutta, Mousumi; Ghosh, Debosree; Ghosh, Arnab Kumar; Bose, Gargi; Chattopadhyay, Aindrila; Rudra, Smita; Dey, Monalisa; Bandyopadhyay, Arkita; Pattari, Sanjib K; Mallick, Sanjaya; Bandyopadhyay, Debasish

    2014-04-01

    Arsenic is a well known global groundwater contaminant. Exposure of human body to arsenic causes various hazardous effects via oxidative stress. Nutrition is an important susceptible factor which can affect arsenic toxicity by several plausible mechanisms. Development of modern civilization led to alteration in the lifestyle as well as food habits of the people both in urban and rural areas which led to increased use of junk food containing high level of fat. The present study was aimed at investigating the effect of high fat diet on heart and liver tissues of rats when they were co-treated with arsenic. This study was established by elucidating heart weight to body weight ratio as well as analysis of the various functional markers, oxidative stress biomarkers and also the activity of the antioxidant enzymes. Histological analysis confirmed the biochemical investigations. From this study it can be concluded that high fat diet increased arsenic induced oxidative stress. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Abiotic and biotic factors influencing the mobility of arsenic in groundwater of a through-flow island in the Okavango Delta, Botswana

    Science.gov (United States)

    Mladenov, Natalie; Wolski, Piotr; Hettiarachchi, Ganga M.; Murray-Hudson, Michael; Enriquez, Hersy; Damaraju, Sivaramakrishna; Galkaduwa, Madhubhashini B.; McKnight, Diane M.; Masamba, Wellington

    2014-10-01

    The Okavango Delta of Botswana is a large arid-zone wetland comprising 20,000 km2 of permanent and seasonal floodplains and over 100,000 islands. It has been shown that island groundwater can have very high dissolved arsenic (As) concentration, but the abiotic and biotic controls on As mobility are not well understood in this setting. At New Island, an island located in the seasonal swamp, dissolved As concentration increased from below detection limits in the surface water to 180 μg/L in groundwater, present as As(III) species. We investigated the relative importance of hydrologic, geochemical, and geomicrobial processes, as well as influences of recent extreme flooding events, in mobilizing and sequestering As in the shallow groundwater system under this island. Our results suggest that evapotranspiration and through-flow conditions control the location of the high arsenic zone. A combination of processes is hypothesized to control elevated As in the concentration zone of New Island: high evapotranspiration rates concentrate As and other solutes, more alkaline pH leads to desorption of arsenic or dissolution of arsenic sulfides, and formation of thioarsenic complexes acts to keep arsenic in solution. Evidence from X-ray absorption near-edge structure spectroscopy (XANES) and sulfate reducing bacteria (SRB) measurements further suggests that SRBs influence arsenic sequestration as orpiment (As2S3). Although dissolved organic matter (DOM) was not significantly correlated to dissolved As in the groundwater, our results suggest that DOM may serve as an electron donor for sulfate reduction or other microbial reactions that influence redox state and As mobility. These results have important implications for water management in the region and in other large wetland environments. The processes evaluated in this study are also relevant for arsenic removal in subsurface constructed wetland systems that may exhibit rapidly changing processes over small spatial scales.

  18. Identifying sources and controlling factors of arsenic release in saline groundwater aquifers

    Directory of Open Access Journals (Sweden)

    C.-W. Liu

    2013-08-01

    Full Text Available An integrated hydrogeochemical study is carried out to realize the occurrence of arsenic (As in a saline aquifer. Saline groundwater was mostly concentrated in the uppermost aquifer and non-saline water was in the lower aquifer in the study area. High As concentrations were found in both uppermost and lower aquifers. No correlation among salination, well depth and As concentration was observed. Both reducing and oxidizing forms of Fe oxyhydroxides were identified in the magnetic fractions, which were concentrated by high gradient magnetic separation (HGMS technique, revealing that the redox cycling of Fe occurred in the subsurface. High levels of Fe, HCO3-, DOC and NH4+ concentrations accompanying alkaline pH in the As-rich groundwater were consistent with the mechanism triggered by the microbial-mediated reductive dissolution of Fe oxyhydroxides. A threshold value of 50 μg L−1. As concentration was used as an indicator for identification of active proceeding reductive dissolution of As-bearing Fe oxyhydroxides in the saline aquifer. Desorption behaviors of As were relevant to its valence in the sediments and the co-existence of anions. Experimental and numerical results showed that additions of Cl- and SO42-, which represented the main anions of saline water, had minor effect on leaching sedimentary As. Although bicarbonate addition resulted in less As desorption than that of phosphate on a molar basis, the contribution of bicarbonate to the total release of As was greater than phosphate due to the much higher concentration of bicarbonate in groundwater and the associated microbial mediation. Collectively, the chemical effect of saline water on the As-release to groundwater is mild in the coastal aquifer.

  19. Use of arsenic contaminated irrigation water for lettuce cropping: effects on soil, groundwater, and vegetal.

    Science.gov (United States)

    Beni, Claudio; Marconi, Simona; Boccia, Priscilla; Ciampa, Alessandra; Diana, Giampietro; Aromolo, Rita; Sturchio, Elena; Neri, Ulderico; Sequi, Paolo; Valentini, Massimiliano

    2011-10-01

    The present study investigated the effects of using arsenic (As) contaminated irrigation water in Lactuca sativa L. cropping. Two different arsenic concentrations, i.e., 25 and 85 μg L(-1) and two different soils, i.e., sandy and clay loam, were taken into account. We determined the arsenic mobility in the different soil fractions, its amount in groundwater, and the phytotoxicity and genotoxicity. Nuclear magnetic resonance (NMR) and inductively coupled plasma (ICP) were used to assess the lettuce metabolic profile changes and the arsenic uptake by the plant, respectively, as a function of the various conditions studied, i.e., As content and type of soil. Data indicated that at both concentrations in sandy soil, arsenic is in part quickly leached and thus present in groundwater and in part absorbed by the vegetable, being therefore readily available for assimilation by consumption. NMR results reported a large modification of the metabolic pattern, which was depending on the pollutant amount. In clay loam soil, the groundwater had a low As content with respect to sandy soil, and NMR and ICP performed on the lettuce did not reveal severe changes related to As, most likely because the metalloid is bound to the colloidal fraction.

  20. Occurrence and treatment of arsenic in groundwater and soil in northern Mexico and southwestern USA.

    Science.gov (United States)

    Camacho, Lucy Mar; Gutiérrez, Mélida; Alarcón-Herrera, Maria Teresa; Villalba, Maria de Lourdes; Deng, Shuguang

    2011-04-01

    This review focuses on the occurrence and treatment of arsenic (As) in the arid region of northern Mexico (states of Chihuahua and Coahuila) and bordering states of the southwestern US (New Mexico, Arizona, and Texas), an area known for having high As concentrations. Information assembled and assessed includes the content and probable source of As in water, soil, and sediments and treatment methods that have been applied in the area. High As concentrations were found mainly in groundwater, their source being mostly from natural origin related to volcanic processes with significant anthropogenic contributions near mining and smelting of ores containing arsenic. The affinity of As for solid phases in alkaline conditions common to arid areas precludes it from being present in surface waters, accumulating instead in sediments and shifting its threat to its potential remobilization in reservoir sediments and irrigation waterways. Factors such as oxidation and pH that affect the mobility of As in the subsurface environment are mentioned. Independent of socio-demographic variables, nutritional status, and levels of blood lead, cognitive development in children is being affected when exposed to As. Treatments known to effectively reduce As content to safe drinking water levels as well as those that are capable of reducing As content in soils are discussed. Besides conventional methods, emergent technologies, such as phytoremediation, offer a viable solution to As contamination in drinking water.

  1. Groundwater arsenic contamination on the Ganges Delta: biogeochemistry, hydrology, human perturbations, and human suffering on a large scale

    Science.gov (United States)

    Harvey, Charles F.; Swartz, Christopher H.; Badruzzaman, Abu Bohran M.; Keon-Blute, Nicole; Yu, Winston; Ali, M. Ashraf; Jay, Jenny; Beckie, Roger; Niedan, Volker; Brabander, Daniel; Oates, Peter M.; Ashfaque, Khandaker N.; Islam, Shafiqul; Hemond, Harold F.; Ahmed, M. Feroze

    2005-02-01

    Over the last several decades, much of population of Bangladesh and West Bengal switched their water supply from surface water to groundwater. Tragically, much of the region's groundwater is dangerously contaminated by arsenic, and consumption of this water has already created severe health effects. Here we consider how groundwater flow may affect arsenic biogeochemistry and we compare the vertical patterns of groundwater chemistry at our intensive study site with the average values across the country. Detailed hydraulic data are presented from our field site that begins to characterize the groundwater flow system. To cite this article: C.F. Harvey et al., C. R. Geoscience 337 (2005).

  2. Health burden of skin lesions at low arsenic exposure through groundwater in Pakistan. Is river the source?

    Science.gov (United States)

    Fatmi, Zafar; Azam, Iqbal; Ahmed, Faiza; Kazi, Ambreen; Gill, Albert Bruce; Kadir, Muhmmad Masood; Ahmed, Mubashir; Ara, Naseem; Janjua, Naveed Zafar

    2009-07-01

    A significant proportion of groundwater in south Asia is contaminated with arsenic. Pakistan has low levels of arsenic in groundwater compared with China, Bangladesh and India. A representative multi-stage cluster survey conducted among 3874 persons > or = 15 years of age to determine the prevalence of arsenic skin lesions, its relation with arsenic levels and cumulative arsenic dose in drinking water in a rural district (population: 1.82 million) in Pakistan. Spot-urine arsenic levels were compared among individuals with and without arsenic skin lesions. In addition, the relation of age, body mass index, smoking status with arsenic skin lesions was determined. The geographical distribution of the skin lesions and arsenic-contaminated wells in the district were ascertained using global positioning system. The total arsenic, inorganic and organic forms, in water and spot-urine samples were determined by atomic absorption spectrophotometry. The prevalence of skin lesions of arsenic was estimated for complex survey design, using surveyfreq and surveylogistic options of SAS 9.1 software.The prevalence of definitive cases i.e. hyperkeratosis of both palms and soles, was 3.4 per 1000 and suspected cases i.e. any sign of arsenic skin lesions (melanosis and/or keratosis), were 13.0 per 1000 among > or = 15-year-old persons in the district. Cumulative arsenic exposure (dose) was calculated from levels of arsenic in water and duration of use of current drinking water source. Prevalence of skin lesions increases with cumulative arsenic exposure (dose) in drinking water and arsenic levels in urine. Skin lesions were 2.5-fold among individuals with BMI Pakistan. Further investigations and focal mitigation measures for arsenic may be carried out alongside Indus River.

  3. Mobilization of arsenic and other naturally occurring contaminants in groundwater of the Main Ethiopian Rift aquifers.

    Science.gov (United States)

    Rango, Tewodros; Vengosh, Avner; Dwyer, Gary; Bianchini, Gianluca

    2013-10-01

    This study investigates the mechanisms of arsenic (As) and other naturally occurring contaminants (F(-), U, V, B, and Mo) mobilization from Quaternary sedimentary aquifers of the Main Ethiopian Rift (MER) and their enrichment in the local groundwater. The study is based on systematic measurements of major and trace elements as well as stable oxygen and hydrogen isotopes in groundwater, coupled with geochemical and mineralogical analyses of the aquifer rocks. The Rift Valley aquifer is composed of rhyolitic volcanics and Quaternary lacustrine sediments. X-ray fluorescence (XRF) results revealed that MER rhyolites (ash, tuff, pumice and ignimbrite) and sediments contain on average 72 wt. % and 65 wt. % SiO2, respectively. Petrographic studies of the rhyolites indicate predominance of volcanic glass, sanidine, pyroxene, Fe-oxides and plagioclase. The As content in the lacustrine sediments (mean = 6.6 mg/kg) was higher than that of the rhyolites (mean: 2.5 mg/kg). The lacustrine aquifers of the Ziway-Shala basin in the northern part of MER were identified as high As risk zones, where mean As concentration in groundwater was 22.4 ± 33.5 (range of 0.60-190 μg/L) and 54% of samples had As above the WHO drinking water guideline value of 10 μg/L. Field As speciation measurements showed that most of the groundwater samples contain predominantly (~80%) arsenate-As(V) over arsenite-As(III) species. The As speciation together with field data of redox potential (mean Eh = +73 ± 65 mV) and dissolved-O2 (6.6 ± 2.2 mg/L) suggest that the aquifer is predominantly oxidative. Water-rock interactions, including the dissolution of volcanic glass produces groundwater with near-neutral to alkaline pH (range 6.9-8.9), predominance of Na-HCO3 ions, and high concentration of SiO2 (mean: 85.8 ± 11.3 mg/L). The groundwater data show high positive correlation of As with Na, HCO3, U, B, V, and Mo (R(2) > 0.5; p ~8, reflecting the pH-dependence of their mobilization. Based on the

  4. Status of groundwater arsenic contamination in Bangladesh: a 14-year study report.

    Science.gov (United States)

    Chakraborti, Dipankar; Rahman, Mohammad Mahmudur; Das, Bhaskar; Murrill, Matthew; Dey, Sankar; Chandra Mukherjee, Subhas; Dhar, Ratan Kumar; Biswas, Bhajan Kumar; Chowdhury, Uttam Kumar; Roy, Shibtosh; Sorif, Shahariar; Selim, Mohammad; Rahman, Mahmuder; Quamruzzaman, Quazi

    2010-11-01

    Since 1996, 52,202 water samples from hand tubewells were analyzed for arsenic (As) by flow injection hydride generation atomic absorption spectrometry (FI-HG-AAS) from all 64 districts of Bangladesh; 27.2% and 42.1% of the tubewells had As above 50 and 10 μg/l, respectively; 7.5% contained As above 300 μg/l, the concentration predicting overt arsenical skin lesions. The groundwater of 50 districts contained As above the Bangladesh standard for As in drinking water (50 μg/l), and 59 districts had As above the WHO guideline value (10 μg/l). Water analyses from the four principal geomorphological regions of Bangladesh showed that hand tubewells of the Tableland and Hill tract regions are primarily free from As contamination, while the Flood plain and Deltaic region, including the Coastal region, are highly As-contaminated. Arsenic concentration was usually observed to decrease with increasing tubewell depth; however, 16% of tubewells deeper than 100 m, which is often considered to be a safe depth, contained As above 50 μg/l. In tubewells deeper than 350 m, As >50 μg/l has not been found. The estimated number of tubewells in 50 As-affected districts was 4.3 million. Based on the analysis of 52,202 hand tubewell water samples during the last 14 years, we estimate that around 36 million and 22 million people could be drinking As-contaminated water above 10 and 50 μg/l, respectively. However for roughly the last 5 years due to mitigation efforts by the government, non-governmental organizations and international aid agencies, many individuals living in these contaminated areas have been drinking As-safe water. From 50 contaminated districts with tubewell As concentrations >50 μg/l, 52% of sampled hand tubewells contained As poisoning and to prevent this disaster from continuing to plague individuals in the future.

  5. Influence Of Groundwater Discharge On Arsenic Contamination In Sediments

    Science.gov (United States)

    A field investigation was conducted to evaluate the impact of a discharging arsenic plume on sediment contaminant characteristics at a site adjacent to a landfill in northeastern Massachusetts. Site characterization included assessment of the hydrologic and chemical samples coll...

  6. Chronic arsenic poisoning from burning high-arsenic-containing coal in Guizhou, China

    Energy Technology Data Exchange (ETDEWEB)

    Liu, J.; Zheng, B.S.; Aposhian, H.V.; Zhou, Y.S.; Chen, M.L.; Zhang, A.H.; Waalkes, M.P. [NIEHS, Research Triangle Park, NC (USA)

    2002-07-01

    Arsenic is an environmental hazard and the reduction of drinking water arsenic levels is under consideration. People are exposed to arsenic not only through drinking water but also through arsenic-contaminated air and food. Here the health effects of arsenic exposure from burning high arsenic-containing coal in Guizhou, China was investigated. Coal is burned inside the home in open pits for daily cooking and crop drying, producing a high concentration of arsenic in indoor air. Arsenic in the air coats and permeates food being dried producing high concentrations in food; however, arsenic concentrations in the drinking water are in the normal range. The estimated sources of total arsenic exposure in this area are from arsenic-contaminated food (50-80%), air (10-20%), water (1-5%), and direct contact in coal-mining workers (1%). At least 3,000 patients with arsenic poisoning were found in the Southwest Prefecture of Guizhou, and approximately 200,000 people are at risk for such over exposures. Skin lesions are common, including keratosis of the hands and feet, pigmentation on the trunk, skin ulceration, and skin cancers. Toxicities to internal organs, including lung dysfunction, neuropathy, and nephrotoxicity, are clinically evident. The prevalence of hepatomegaly was 20%, and cirrhosis, ascites, and liver cancer are the most serious outcomes of arsenic poisoning. The Chinese government and international organizations are attempting to improve the house conditions and the coal source, and thereby protect human health in this area.

  7. Geochemical modeling and multivariate statistical evaluation of trace elements in arsenic contaminated groundwater systems of Viterbo Area, (Central Italy).

    Science.gov (United States)

    Sappa, Giuseppe; Ergul, Sibel; Ferranti, Flavia

    2014-01-01

    Contamination of groundwater by naturally occurring arsenic has recently become a disturbing environmental problem in Viterbo area, Central Italy. Arsenic concentrations in most of the public supply networks exceed the maximum allowable limit of 10 μg/l (WHO) for drinking water. The primary purpose of this paper is to obtain a better understanding of the factors contributing to the high levels of As in water supply networks. This study focuses on (a) the determination of basic hydrochemical characteristics of groundwater, (b) the identification of the major sources and processes controlling the As contamination in public supply networks, (c) to find out possible relationships among the As and other trace elements through principal component analysis (PCA). Groundwater samples from public water supply wells and springs were collected and analysed for physico-chemical parameters and trace elements. Springs and well water samples are predominantly of the Na-HCO3, Na -Ca-HCO3 and Ca-HCO3 types and the highest arsenic concentrations were observed in Na-HCO3 type water. Eh-pH diagrams reveal that H2AsO4 (-) and HAsO4 (2-), As(V) arsenate, are the dominating As species highlighting slightly to moderately oxidizing conditions. Geochemical modeling indicates that arsenic-bearing phases were undersaturated in the groundwater, however most of the samples were saturated with respect to Fe (i.e. magnetite, hematite and goethite) and Al (diaspore and boehmite) oxide and hydroxide minerals. Concentrations of As, Li, B, Co, Sr, Mo, U and Se are highly correlated (r > 0.7) with each other, however in some groundwater samples As show also good correlations (r > 0.5) with Fe and Mn elements reflecting the relationships among the trace elements result from different geochemical processes. Evaluation of the principal component (PCA) analysis and geochemical modeling suggest that the occurrence of As and other trace element concentrations in groundwater are probably derived

  8. Lead isotopic compositions of soil and near-surface till profiles from a watershed containing arsenic-enriched groundwater in coastal Maine

    Science.gov (United States)

    Ayuso, Robert; Foley, Nora; Wandless, Gregory; Dillingham, Jeremy; Colvin, Anna

    2005-01-01

    Lead isotope compositions of soils and near-surface tills from an area of coastal Maine known to have groundwater with anomalously high arsenic contents were measured in order to determine the source of the lead and, by inference, possible sources of arsenic. Five soil and till sites were selected for detailed chemical and isotopic analysis. To construct profiles of the soil and till horizons, five samples were collected at 10-cm intervals from the surface to the base of each horizon. Total lead and arsenic concentrations and lead isotopic compositions were measured for 48 leaches and bulk residues. The soils and tills are underlain by sulfidic schists of the Penobscot Formation. Several generations of minerals containing arsenic and lead exist in the regional bedrock, including rock-forming silicates (feldspar and micas), sulfide minerals formed during diagenesis (for example, arsenic-rich pyrite), and sulfide and oxide minerals that formed as a result of Silurian metamorphic and igneous events (for example, arsenopyrite, galena, iron-oxides, and arsenic-sulfides). A young group of secondary minerals (for example, iron-hydroxides, arsenic-hydroxides, lead-sulfate, and arsenic-jarosite) formed from recent weathering and pedogenic processes.

  9. Arsenic removal via electrocoagulation from heavy metal contaminated groundwater in La Comarca Lagunera Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Parga, Jose R. [Institute Technology of Saltillo, Department of Metallurgy and Materials Science, V. Carranza 2400, C.P. 25280, Saltillo, Coahuila, Mexico (Mexico)]. E-mail: drjrparga@hotmail.com; Cocke, David L. [Lamar University, Gill Chair of Chemistry and Chemical Engineering, Beaumont, TX 77710 (United States); Valenzuela, Jesus L. [University of Sonora, Hermosillo, Sonora, Mexico (Mexico); Gomes, Jewel A. [Lamar University, Gill Chair of Chemistry and Chemical Engineering, Beaumont, TX 77710 (United States); Kesmez, Mehmet [Lamar University, Gill Chair of Chemistry and Chemical Engineering, Beaumont, TX 77710 (United States); Irwin, George [Lamar University, Department of Chemistry and Physics, Beaumont, TX 77710 (United States); Moreno, Hector [Lamar University, Gill Chair of Chemistry and Chemical Engineering, Beaumont, TX 77710 (United States); Weir, Michael [Lamar University, Gill Chair of Chemistry and Chemical Engineering, Beaumont, TX 77710 (United States)

    2005-09-30

    Arsenic contamination is an enormous worldwide problem. A large number of people dwelling in Comarca Lagunera, situated in the central part of northern Mexico, use well water with arsenic in excess of the water standard regulated by the Secretary of Environment and Natural Resources of Mexico (SEMARNAT), to be suitable for human health. Individuals with lifetime exposure to arsenic develop the classic symptoms of arsenic poisoning. Among several options available for removal of arsenic from well water, electrocoagulation (EC) is a very promising electrochemical treatment technique that does not require the addition of chemicals or regeneration. First, this study will provide an introduction to the fundamental concepts of the EC method. In this study, powder X-ray diffraction, scanning electron microscopy, transmission Moessbauer spectroscopy and Fourier transform infrared spectroscopy were used to characterize the solid products formed at iron electrodes during the EC process. The results suggest that magnetite particles and amorphous iron oxyhydroxides present in the EC products remove arsenic(III) and arsenic(V) with an efficiency of more than 99% from groundwater in a field pilot scale study.

  10. Arsenic removal via electrocoagulation from heavy metal contaminated groundwater in La Comarca Lagunera México.

    Science.gov (United States)

    Parga, Jose R; Cocke, David L; Valenzuela, Jesus L; Gomes, Jewel A; Kesmez, Mehmet; Irwin, George; Moreno, Hector; Weir, Michael

    2005-09-30

    Arsenic contamination is an enormous worldwide problem. A large number of people dwelling in Comarca Lagunera, situated in the central part of northern México, use well water with arsenic in excess of the water standard regulated by the Secretary of Environment and Natural Resources of México (SEMARNAT), to be suitable for human health. Individuals with lifetime exposure to arsenic develop the classic symptoms of arsenic poisoning. Among several options available for removal of arsenic from well water, electrocoagulation (EC) is a very promising electrochemical treatment technique that does not require the addition of chemicals or regeneration. First, this study will provide an introduction to the fundamental concepts of the EC method. In this study, powder X-ray diffraction, scanning electron microscopy, transmission Mössbauer spectroscopy and Fourier transform infrared spectroscopy were used to characterize the solid products formed at iron electrodes during the EC process. The results suggest that magnetite particles and amorphous iron oxyhydroxides present in the EC products remove arsenic(III) and arsenic(V) with an efficiency of more than 99% from groundwater in a field pilot scale study.

  11. Health burden of skin lesions at low arsenic exposure through groundwater in Pakistan. Is river the source?

    Energy Technology Data Exchange (ETDEWEB)

    Fatmi, Zafar, E-mail: zafar.fatmi@aku.edu [Department of Community Health Sciences, Aga Khan University, Stadium Road, P.O. Box 3500, Karachi (Pakistan); Azam, Iqbal; Ahmed, Faiza; Kazi, Ambreen; Gill, Albert Bruce; Kadir, Muhmmad Masood; Ahmed, Mubashir; Ara, Naseem; Janjua, Naveed Zafar [Department of Community Health Sciences, Aga Khan University, Stadium Road, P.O. Box 3500, Karachi (Pakistan)

    2009-07-15

    A significant proportion of groundwater in south Asia is contaminated with arsenic. Pakistan has low levels of arsenic in groundwater compared with China, Bangladesh and India. A representative multi-stage cluster survey conducted among 3874 persons {>=}15 years of age to determine the prevalence of arsenic skin lesions, its relation with arsenic levels and cumulative arsenic dose in drinking water in a rural district (population: 1.82 million) in Pakistan. Spot-urine arsenic levels were compared among individuals with and without arsenic skin lesions. In addition, the relation of age, body mass index, smoking status with arsenic skin lesions was determined. The geographical distribution of the skin lesions and arsenic-contaminated wells in the district were ascertained using global positioning system. The total arsenic, inorganic and organic forms, in water and spot-urine samples were determined by atomic absorption spectrophotometry. The prevalence of skin lesions of arsenic was estimated for complex survey design, using surveyfreq and surveylogistic options of SAS 9.1 software.The prevalence of definitive cases i.e. hyperkeratosis of both palms and soles, was 3.4 per 1000 and suspected cases i.e. any sign of arsenic skin lesions (melanosis and/or keratosis), were 13.0 per 1000 among {>=}15-year-old persons in the district. Cumulative arsenic exposure (dose) was calculated from levels of arsenic in water and duration of use of current drinking water source. Prevalence of skin lesions increases with cumulative arsenic exposure (dose) in drinking water and arsenic levels in urine. Skin lesions were 2.5-fold among individuals with BMI <18.5 kg/m{sup 2}. Geographically, more arsenic-contaminated wells and skin lesions were alongside Indus River, suggests a strong link between arsenic contamination of groundwater with proximity to river.This is the first reported epidemiological and clinical evidence of arsenic skin lesions due to groundwater in Pakistan. Further

  12. Geospatial modeling of widespread arsenic contamination in unconfined, high-pH aquifers in Pakistan

    Science.gov (United States)

    Podgorski, J. E.; Eqani, S. A. M. A. S.; Heqing, S.; Berg, M.

    2016-12-01

    Arsenic-contaminated aquifers are presently estimated to affect approximately 150 million people worldwide. However, the full extent of the problem remains unknown. This is the case also in Pakistan, where previously conducted studies have focused only on individual areas of limited extent. Using a new dataset of nearly 1,200 groundwater quality samples throughout Pakistan along with existing measurements, we have created statistically based hazard and risk models of arsenic contamination in groundwater for thresholds of 10 and 50 µg/L, corresponding to the WHO and local guidelines, respectively. Logistic regression analysis was conducted using a variety of environmental indicators selected for their potential association with arsenic release and accumulation. The best logistic regression was achieved using the predictor variables of slope, Holocene geology, fluvisols, soil pH and soil organic carbon. The resultant hazard model (attached figure) shows that much of the flat, arid Indus Plain has a high probability of elevated arsenic concentrations. Other indicators that are highly correlated with elevated arsenic are aridity and proportion of land under irrigation. Unlike other known arsenic-contaminated areas of Asia, the arsenic release process in the arid Indus Plain appears to be dominated by elevated-pH dissolution, which is a consequence of alkaline topsoil and unconfined aquifers. However, pockets of reductive dissolution may also occur, primarily as a result of local groundwater contamination from municipal and agricultural sewage. Although the average pH of surface soil in the Indus Plain generally ranges between 8.0-8.5, the average pH of groundwater samples with high arsenic from this area is only 7.6. A likely scenario is that pH-induced arsenic release is occurring in the surface sediments and migrating downward into the underlying unconfined aquifer. The role of irrigation in arsenic release is unclear, although it could have a significant influence

  13. Brahmaputra river basin groundwater: Solute distribution, chemical evolution and arsenic occurrences in different geomorphic settings

    Directory of Open Access Journals (Sweden)

    Swati Verma

    2015-09-01

    New hydrological insights for the region: Most groundwater solutes of RCD and YA terrains were derived from both silicate weathering and carbonate dissolution, while silicate weathering process dominates the solute contribution in OA groundwater. Groundwater samples from all terrains are postoxic with mean pe values between Fe(III and As(V–As(III reductive transition. While, reductive dissolution of (Fe–MnOOH is the dominant mechanism of As mobilization in RCD and YA aquifers, As in OA and PD aquifers could be mobilized by combined effect of pH dependent sorption and competitive ion exchange. The present study focuses on the major ion chemistry as well as the chemistry of the redox sensitive solutes of the groundwater in different geomorphic settings and their links to arsenic mobilization in groundwater.

  14. Preserving the distribution of inorganic arsenic species in groundwater and acid mine drainage samples

    Science.gov (United States)

    Bednar, A.J.; Garbarino, J.R.; Ranville, J.F.; Wildeman, T.R.

    2002-01-01

    The distribution of inorganic arsenic species must be preserved in the field to eliminate changes caused by metal oxyhydroxide precipitation, photochemical oxidation, and redox reactions. Arsenic species sorb to iron and manganese oxyhydroxide precipitates, and arsenite can be oxidized to arsenate by photolytically produced free radicals in many sample matrices. Several preservatives were evaluated to minimize metal oxyhydroxide precipitation, such as inorganic acids and ethylenediaminetetraacetic acid (EDTA). EDTA was found to work best for all sample matrices tested. Storing samples in opaque polyethylene bottles eliminated the effects of photochemical reactions. The preservation technique was tested on 71 groundwater and six acid mine drainage samples. Concentrations in groundwater samples reached 720 ??g-As/L for arsenite and 1080 ??g-As/L for arsenate, and acid mine drainage samples reached 13 000 ??g-As/L for arsenite and 3700 ??g-As/L for arsenate. The arsenic species distribution in the samples ranged from 0 to 90% arsenite. The stability of the preservation technique was established by comparing laboratory arsenic speciation results for samples preserved in the field to results for subsamples speciated onsite. Statistical analyses indicated that the difference between arsenite and arsenate concentrations for samples preserved with EDTA in opaque bottles and field speciation results were analytically insignificant. The percentage change in arsenite:arsenate ratios for a preserved acid mine drainage sample and groundwater sample during a 3-month period was -5 and +3%, respectively.

  15. Characterisation of organic matter associated with groundwater arsenic in reducing aquifers of southwestern Taiwan.

    Science.gov (United States)

    Al Lawati, Wafa M; Jean, Jiin-Shuh; Kulp, Thomas R; Lee, Ming-Kuo; Polya, David A; Liu, Chia-Chuan; van Dongen, Bart E

    2013-11-15

    Arsenic (As) in groundwaters extensively used by people across the world constitutes a serious public health threat. The importance of organic matter (OM) as an electron donor in microbially-mediated reduction of As(V) or Fe(III)-bearing As-host minerals leading to mobilisation of solid-phase arsenic is widely recognised. Notwithstanding this, there are few studies characterising OM in such aquifers and, in particular, there is a dearth of data from the classic arsenic bearing aquifers in southwestern Taiwan. Organic geochemical analyses of sediments from a known groundwater arsenic hot-spot in southwestern Taiwan revealed contributions of thermally mature and plant derived origin, consistent with OM sources in all other Asian groundwater aquifer sediments analysed to date, indicating comparable sources and routes of OM transfer. The combined results of amended As(V) reduction assays with the organic geochemical analysis revealed that the microbiological process of dissimilatory As(V) reduction is active in this aquifer, but it is not controlled by a specific source of analysed OM. These indicate that (i) part of the OM that was considered to be less bio-available could still be used as an electron donor or (ii) other electron donors, not analysed in present study, could be controlling the rate of As release.

  16. Assessment of the physical and chemical sustainability of deep, low-arsenic groundwater in the Bengal Basin: Regional- and local-scale considerations (Invited)

    Science.gov (United States)

    Michael, H. A.; Voss, C. I.; Radloff, K. A.; Zheng, Y.

    2010-12-01

    Millions of people in Bangladesh and West Bengal, India are drinking groundwater from Bengal Basin aquifers with unsafe levels of arsenic. A promising mitigation option is development of deep groundwater in areas where water quality at depth is high. Deep groundwater is already in use in many areas, but proper management is necessary to maintain a safe water supply for this and future generations. Pumping at depth may induce downward migration of arsenic from shallow, contaminated aquifer zones in areas where physical (groundwater flowpaths) and chemical (arsenic sorption or reaction) protection does not occur or is insufficient. Understanding these protection mechanisms and conditions in which they are undermined is critical to determining the sustainability of mitigation options. We use a basin-scale groundwater flow and solute transport model considering advective flowpaths and dispersive solute transport with sorption to investigate the sustainability of deep groundwater pumping options within the high-arsenic area of the Bengal Basin. On a large scale, distributed pumping for both domestic and irrigation use is considered, including future scenarios in which domestic use increases due to population growth or piped supply. Regional modeling indicates that limited pumping at depth (current domestic supply and future supply under sorbing conditions) is critical to sustainability of the deep groundwater resource. However, basin-scale modeling does not consider effects of point pumping from community or municipal wells, as may be installed for this mitigation option, or local geologic conditions. Small-scale models are developed to consider these effects, and recommendations for the future are made.

  17. Determinants of arsenicosis patients' perception and social implications of arsenic poisoning through groundwater in Bangladesh.

    Science.gov (United States)

    Sarker, M Mizanur Rahman

    2010-10-01

    Adverse human health effects ranging from skin lesions to internal cancers as well as widespread social and psychological problems caused by arsenic contaminated drinking water in Bangladesh may be the biggest arsenic calamity in the world. From an arsenicosis patients survey, this paper empirically analyzes the determinants of arsenicosis patients' perception about chronic arsenic poisoning and social and psychological implications of arsenicosis. In this study, cross-sectional data were collected from the Matlab and Hajiganj Upzillas of Chandpur district which are known to be highly contaminated with arsenic in their underground water. Respondents informed that arsenic poisoning causes a wide range of social and psychological problems. Female respondents were less vulnerable in the case of social problems (p arsenic exposure for abating the health burden as well as social and psychological problems.

  18. Removal of the arsenic from contaminated groundwater with use of the new generation of MicroDrop Aqua system

    DEFF Research Database (Denmark)

    Kowalski, Krzysztof; Søgaard, Erik Gydesen

    2012-01-01

    The results from a new pilot scale plant of the MicroDrop Aqua arsenic removal technology are introduced. The technology is based on the employing of electrochemical iron dissolution and efficient aeration prior to sand filtration. The pilot treatment was used to study effectiveness of iron relea...... addition and easily to remove arsenic from contaminated groundwater....

  19. Spatial relationship of groundwater arsenic distribution with regional topography and water-table fluctuations in the shallow aquifers in Bangladesh

    Science.gov (United States)

    Shamsudduha, M.; Marzen, L. J.; Uddin, A.; Lee, M.-K.; Saunders, J. A.

    2009-06-01

    The present study has examined the relationship of groundwater arsenic (As) levels in alluvial aquifers with topographic elevation, slope, and groundwater level on a large basinal-scale using high-resolution (90 m × 90 m) Shuttle Radar Topography Mission (SRTM) digital elevation model and water-table data in Bangladesh. Results show that high As (>50 μg/l) tubewells are located in low-lying areas, where mean surface elevation is approximately 10 m. Similarly, high As concentrations are found within extremely low slopes (Bangladesh Water Development Board) was mapped using water-table data from 950 shallow (depth Works Datum (PWD) level. Extremely low groundwater gradients (0.01-0.001 m/km) within the GBM delta complex hinder groundwater flow and cause slow flushing of aquifers. Low elevation and gentle slope favor accumulation of finer sediments, As-carrying iron-oxyhydroxide minerals, and abundant organic matter within floodplains and alluvial deposits. At low horizontal hydraulic gradients and under reducing conditions, As is released in groundwater by microbial activity, causing widespread contamination in the low-lying deltaic and floodplain areas, where As is being recycled with time due to complex biogeochemical processes.

  20. Natural contamination with arsenic and other trace elements in groundwater of the Central-West region of Chaco, Argentina.

    Science.gov (United States)

    Blanes, Patricia S; Buchhamer, Edgar E; Giménez, María C

    2011-01-01

    This study covered the central agricultural region of the Chaco province, which lacks a permanent river networks. However, during the rainy period there is localized groundwater recharge. About 84 groundwater samples were taken during the period April-December 2007. These groundwater samples were collected from two different depths: 62 samples from shallow wells (4 to 20 m) and 24 samples from deep wells (20 to 100 m). Chemical variables were determined: pH, specific conductance, total dissolved solid, hardness, alkalinity, HCO(3)-, CO(3)(2-), SO(4)(2-), Cl-, NO(3)-, NO(2) -, NH(4)+, F-, As((tot)), Na+, K+, Ca2+, Mg2+, Fe, Cu, Ni, Pb and Zn. The chemical composition of groundwater in the study area is dominantly sodium bicarbonate and sodium chloride bicarbonate, comprising more than 60% (52/86) of shallow and deep groundwater samples. Of the 86 analyzed groundwater samples, 88% exceeded the WHO (World Health Organization) and CAA (Código Alimentario Argentino) standards (10 μg/L) for As (arsenic) and 9% exceeded the WHO standard (1.5 mg/L) for F(-).Groundwater highly contaminated with As (max. 1,073 μg/L) and F- (max. 4.2 mg/L) was found in shallow aquifer. The contaminated groundwater is characterized by high pH (max. 8.9), alkalinity (max. HCO(3)- 1,932 mg/L), SO(4)(2-) (max. 11,862 mg/L), Na(+) (max. 3,158 mg/L), Cl(-) (max. 10,493 mg/L) and electric conductivity greater than 33.3 μS/cm. Other associated elements (Ni, Pb, Cu and Zn) are present in low concentrations, except for Fe that in 32% of samples exceeded the guideline value of 0.3 mg/L suggested by the CAA.

  1. Groundwater dynamics and arsenic mobilization in Bangladesh assessed using noble gases and tritium.

    Science.gov (United States)

    Klump, Stephan; Kipfer, Rolf; Cirpka, Olaf A; Harvey, Charles F; Brennwald, Matthias S; Ashfaque, Khandaker N; Badruzzaman, Abu Borhan M; Hug, Stephan J; Imboden, Dieter M

    2006-01-01

    The contamination of groundwater by geogenic arsenic is the cause of major health problems in south and southeast Asia. Various hypotheses proposing that As is mobilized by the reduction of iron (oxy)hydroxides are now under discussion. One important and controversial question concerns the possibility that As contamination might be related to the extraction of groundwater for irrigation purposes. If As were mobilized by the inflow of re-infiltrating irrigation water rich in labile organic carbon, As-contaminated groundwater would have been recharged after the introduction of groundwater irrigation 20-40 years ago. We used environmental tracer data and conceptual groundwater flow and transport modeling to study the effects of groundwater pumping and to assess the role of reinfiltrated irrigation water in the mobilization of As. Both the tracer data and the model results suggest that pumping induces convergent groundwater flow to the depth of extraction and causes shallow, young groundwater to mix with deep, old groundwater. The As concentrations are greatest at a depth of 30 m where these two groundwater bodies come into contact and mix. There, within the mixing zone, groundwater age significantly exceeds 30 years, indicating that recharge of most of the contaminated water occurred before groundwater irrigation became established in Bangladesh. Hence, at least at our study site, the results call into question the validity of the hypothesis that re-infiltrated irrigation water is the direct cause of As mobilization; however, the tracer data suggest that, at our site, hydraulic changes due to groundwater extraction for irrigation might be related to the mobilization of As.

  2. Adsorptive removal of manganese, arsenic and iron from groundwater

    NARCIS (Netherlands)

    Buamah, R.

    2009-01-01

    Arsenic, manganese and iron in drinking water at concentrations exceeding recommended guideline values pose health risks and aesthetic defects. Batch and pilot experiments on manganese adsorption equilibrium and kinetics using iron-oxide coated sand (IOCS), Aquamandix and other media have been

  3. Adsorptive removal of manganese, arsenic and iron from groundwater

    NARCIS (Netherlands)

    Buamah, R.

    2009-01-01

    Arsenic, manganese and iron in drinking water at concentrations exceeding recommended guideline values pose health risks and aesthetic defects. Batch and pilot experiments on manganese adsorption equilibrium and kinetics using iron-oxide coated sand (IOCS), Aquamandix and other media have been inve

  4. Prediction of contamination potential of groundwater arsenic in Cambodia, Laos, and Thailand using artificial neural network.

    Science.gov (United States)

    Cho, Kyung Hwa; Sthiannopkao, Suthipong; Pachepsky, Yakov A; Kim, Kyoung-Woong; Kim, Joon Ha

    2011-11-01

    The arsenic (As) contamination of groundwater has increasingly been recognized as a major global issue of concern. As groundwater resources are one of most important freshwater sources for water supplies in Southeast Asian countries, it is important to investigate the spatial distribution of As contamination and evaluate the health risk of As for these countries. The detection of As contamination in groundwater resources, however, can create a substantial labor and cost burden for Southeast Asian countries. Therefore, modeling approaches for As concentration using conventional on-site measurement data can be an alternative to quantify the As contamination. The objective of this study is to evaluate the predictive performance of four different models; specifically, multiple linear regression (MLR), principal component regression (PCR), artificial neural network (ANN), and the combination of principal components and an artificial neural network (PC-ANN) in the prediction of As concentration, and to provide assessment tools for Southeast Asian countries including Cambodia, Laos, and Thailand. The modeling results show that the prediction accuracy of PC-ANN (Nash-Sutcliffe model efficiency coefficients: 0.98 (traning step) and 0.71 (validation step)) is superior among the four different models. This finding can be explained by the fact that the PC-ANN not only solves the problem of collinearity of input variables, but also reflects the presence of high variability in observed As concentrations. We expect that the model developed in this work can be used to predict As concentrations using conventional water quality data obtained from on-site measurements, and can further provide reliable and predictive information for public health management policies. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. Hydrogeologic framework, arsenic distribution, and groundwater geochemistry of the glacial-sediment aquifer at the Auburn Road landfill superfund site, Londonderry, New Hampshire

    Science.gov (United States)

    Degnan, James R.; Harte, Philip T.

    2013-01-01

    Leachate continues to be generated from landfills at the Auburn Road Landfill Superfund Site in Londonderry, New Hampshire. Impermeable caps on the three landfills at the site inhibit direct infiltration of precipitation; however, high water-table conditions allow groundwater to interact with landfill materials from below, creating leachate and ultimately reducing conditions in downgradient groundwater. Reducing conditions can facilitate arsenic transport by allowing it to stay in solution or by liberating arsenic adsorbed to surfaces and from geologic sources, such as glacial sediments and bedrock. The site occupies a 180-acre parcel of land containing streams, ponds, wetlands, and former gravel pits located in glacial sediment. Four areas, totaling 14 acres, including three landfills and one septage lagoon, were used for waste disposal. The site was closed in 1980 after volatile organic compounds associated with industrial waste dumping were detected. The site was added to the U.S. Environmental Protection Agency National Priority List in 1982, and the landfills were capped in 1996. Although volatile organic compound concentrations in groundwater have declined substantially, some measurable concentrations remain. Temporally variable and persistent elevated arsenic concentrations have been measured in groundwater affected by the landfill leachate. Microbial consumption of carbon found in leachate is a driver of reducing conditions that liberate arsenic at the site. In addition to sources of carbon in landfill leachate, wetland areas throughout the site also could contribute carbon to groundwater, but it is currently unknown if any of the wetland areas have downward or reversing gradients that could allow the infiltration of surface water to groundwater. Red-stained sediments and water indicate iron-rich groundwater discharge to surface water and are also associated with elevated concentrations of arsenic in sediment and groundwater. Ironrich groundwater seeps have

  6. Extensive arsenic contamination in high-pH unconfined aquifers in the Indus Valley

    Science.gov (United States)

    Podgorski, Joel E.; Eqani, Syed Ali Musstjab Akber Shah; Khanam, Tasawar; Ullah, Rizwan; Shen, Heqing; Berg, Michael

    2017-01-01

    Arsenic-contaminated aquifers are currently estimated to affect ~150 million people around the world. However, the full extent of the problem remains elusive. This is also the case in Pakistan, where previous studies focused on isolated areas. Using a new data set of nearly 1200 groundwater quality samples throughout Pakistan, we have created state-of-the-art hazard and risk maps of arsenic-contaminated groundwater for thresholds of 10 and 50 μg/liter. Logistic regression analysis was used with 1000 iterations, where surface slope, geology, and soil parameters were major predictor variables. The hazard model indicates that much of the Indus Plain is likely to have elevated arsenic concentrations, although the rest of the country is mostly safe. Unlike other arsenic-contaminated areas of Asia, the arsenic release process in the arid Indus Plain appears to be dominated by elevated-pH dissolution, resulting from alkaline topsoil and extensive irrigation of unconfined aquifers, although pockets of reductive dissolution are also present. We estimate that approximately 50 million to 60 million people use groundwater within the area at risk, with hot spots around Lahore and Hyderabad. This number is alarmingly high and demonstrates the urgent need for verification and testing of all drinking water wells in the Indus Plain, followed by appropriate mitigation measures. PMID:28845451

  7. Blast furnace residues for arsenic removal from mining-contaminated groundwater.

    Science.gov (United States)

    Carrillo-Pedroza, Fco Raúl; Soria-Aguilar, Ma de Jesús; Martínez-Luevanos, Antonia; Narvaez-García, Víctor

    2014-01-01

    In this work, blast furnace (BF) residues were well characterized and then evaluated as an adsorbent material for arsenic removal from a mining-contaminated groundwater. The adsorption process was analysed using the theories of Freundlich and Langmuir. BF residues were found to be an effective sorbent for As (V) ions. The modelling of adsorption isotherms by empirical models shows that arsenate adsorption is fitted by the Langmuir model, suggesting a monolayer adsorption of arsenic onto adsorbents. Arsenate adsorption onto BF residue is explained by the charge density surface affinity and by the formation of Fe (II) and Fe (III) corrosion products onto BF residue particles. The results indicate that BF residues represent an attractive low-cost absorbent option for the removal of arsenic in wastewater treatment.

  8. Targeting low-arsenic groundwater with mobile-phone technology in Araihazar, Bangladesh.

    Science.gov (United States)

    van Geen, A; Trevisani, M; Immel, J; Jakariya, Md; Osman, N; Cheng, Z; Gelman, A; Ahmed, K M

    2006-09-01

    The Bangladesh Arsenic Mitigation and Water Supply Program (BAMWSP) has compiled field-kit measurements of the arsenic content of groundwater for nearly five million wells. By comparing the spatial distribution of arsenic inferred from these field-kit measurements with geo-referenced laboratory data in a portion of Araihazar upazila, it is shown here that the BAMWSP data could be used for targeting safe aquifers for the installation of community wells in many villages of Bangladesh. Recent experiences with mobile-phone technology to access and update the BAMWSP data in the field are also described. It is shown that the technology, without guaranteeing success, could optimize interventions by guiding the choice of the drilling method that is likely to reach a safe aquifer and identifying those villages where exploratory drilling is needed.

  9. Application of geostatistics with Indicator Kriging for analyzing spatial variability of groundwater arsenic concentrations in Southwest Bangladesh.

    Science.gov (United States)

    Hassan, M Manzurul; Atkins, Peter J

    2011-01-01

    This article seeks to explore the spatial variability of groundwater arsenic (As) concentrations in Southwestern Bangladesh. Facts about spatial pattern of As are important to understand the complex processes of As concentrations and its spatial predictions in the unsampled areas of the study site. The relevant As data for this study were collected from Southwest Bangladesh and were analyzed with Flow Injection Hydride Generation Atomic Absorption Spectrometry (FI-HG-AAS). A geostatistical analysis with Indicator Kriging (IK) was employed to investigate the regionalized variation of As concentration. The IK prediction map shows a highly uneven spatial pattern of arsenic concentrations. The safe zones are mainly concentrated in the north, central and south part of the study area in a scattered manner, while the contamination zones are found to be concentrated in the west and northeast parts of the study area. The southwest part of the study area is contaminated with a highly irregular pattern. A Generalized Linear Model (GLM) was also used to investigate the relationship between As concentrations and aquifer depths. A negligible negative correlation between aquifer depth and arsenic concentrations was found in the study area. The fitted value with 95 % confidence interval shows a decreasing tendency of arsenic concentrations with the increase of aquifer depth. The adjusted mean smoothed lowess curve with a bandwidth of 0.8 shows an increasing trend of arsenic concentration up to a depth of 75 m, with some erratic fluctuations and regional variations at the depth between 30 m and 60 m. The borehole lithology was considered to analyze and map the pattern of As variability with aquifer depths. The study has performed an investigation of spatial pattern and variation of As concentrations.

  10. Arsenic contamination of groundwater: a review of sources, prevalence, health risks, and strategies for mitigation.

    Science.gov (United States)

    Shankar, Shiv; Shanker, Uma; Shikha

    2014-01-01

    Arsenic contamination of groundwater in different parts of the world is an outcome of natural and/or anthropogenic sources, leading to adverse effects on human health and ecosystem. Millions of people from different countries are heavily dependent on groundwater containing elevated level of As for drinking purposes. As contamination of groundwater, poses a serious risk to human health. Excessive and prolonged exposure of inorganic As with drinking water is causing arsenicosis, a deteriorating and disabling disease characterized by skin lesions and pigmentation of the skin, patches on palm of the hands and soles of the feet. Arsenic poisoning culminates into potentially fatal diseases like skin and internal cancers. This paper reviews sources, speciation, and mobility of As and global overview of groundwater As contamination. The paper also critically reviews the As led human health risks, its uptake, metabolism, and toxicity mechanisms. The paper provides an overview of the state-of-the-art knowledge on the alternative As free drinking water and various technologies (oxidation, coagulation flocculation, adsorption, and microbial) for mitigation of the problem of As contamination of groundwater.

  11. Arsenic Contamination of Groundwater: A Review of Sources, Prevalence, Health Risks, and Strategies for Mitigation

    Directory of Open Access Journals (Sweden)

    Shiv Shankar

    2014-01-01

    Full Text Available Arsenic contamination of groundwater in different parts of the world is an outcome of natural and/or anthropogenic sources, leading to adverse effects on human health and ecosystem. Millions of people from different countries are heavily dependent on groundwater containing elevated level of As for drinking purposes. As contamination of groundwater, poses a serious risk to human health. Excessive and prolonged exposure of inorganic As with drinking water is causing arsenicosis, a deteriorating and disabling disease characterized by skin lesions and pigmentation of the skin, patches on palm of the hands and soles of the feet. Arsenic poisoning culminates into potentially fatal diseases like skin and internal cancers. This paper reviews sources, speciation, and mobility of As and global overview of groundwater As contamination. The paper also critically reviews the As led human health risks, its uptake, metabolism, and toxicity mechanisms. The paper provides an overview of the state-of-the-art knowledge on the alternative As free drinking water and various technologies (oxidation, coagulation flocculation, adsorption, and microbial for mitigation of the problem of As contamination of groundwater.

  12. Arsenic Contamination of Groundwater: A Review of Sources, Prevalence, Health Risks, and Strategies for Mitigation

    Science.gov (United States)

    Shikha

    2014-01-01

    Arsenic contamination of groundwater in different parts of the world is an outcome of natural and/or anthropogenic sources, leading to adverse effects on human health and ecosystem. Millions of people from different countries are heavily dependent on groundwater containing elevated level of As for drinking purposes. As contamination of groundwater, poses a serious risk to human health. Excessive and prolonged exposure of inorganic As with drinking water is causing arsenicosis, a deteriorating and disabling disease characterized by skin lesions and pigmentation of the skin, patches on palm of the hands and soles of the feet. Arsenic poisoning culminates into potentially fatal diseases like skin and internal cancers. This paper reviews sources, speciation, and mobility of As and global overview of groundwater As contamination. The paper also critically reviews the As led human health risks, its uptake, metabolism, and toxicity mechanisms. The paper provides an overview of the state-of-the-art knowledge on the alternative As free drinking water and various technologies (oxidation, coagulation flocculation, adsorption, and microbial) for mitigation of the problem of As contamination of groundwater. PMID:25374935

  13. High resolution profile of inorganic aqueous geochemistry and key redox zones in an arsenic bearing aquifer in Cambodia.

    Science.gov (United States)

    Richards, Laura A; Magnone, Daniel; Sovann, Chansopheaktra; Kong, Chivuth; Uhlemann, Sebastian; Kuras, Oliver; van Dongen, Bart E; Ballentine, Christopher J; Polya, David A

    2017-07-15

    Arsenic contamination of groundwaters in South and Southeast Asia is a major threat to public health. In order to better understand the geochemical controls on the mobility of arsenic in a heavily arsenic-affected aquifer in northern Kandal Province, Cambodia, key changes in inorganic aqueous geochemistry have been monitored at high vertical and lateral resolution along dominant groundwater flow paths along two distinct transects. The two transects are characterized by differing geochemical, hydrological and lithological conditions. Arsenic concentrations in groundwater are highly heterogenous, and are broadly positively associated with iron and negatively associated with sulfate and dissolved oxygen. The observed correlations are generally consistent with arsenic mobilization by reductive-dissolution of iron (hydr)oxides. Key redox zones, as identified using groupings of the PHREEQC model equilibrium electron activity of major redox couples (notably ammonium/nitrite; ammonium/nitrate; nitrite/nitrate; dissolved oxygen/water) have been identified and vary with depth, site and season. Mineral saturation is also characterized. Seasonal changes in groundwater chemistry were observed in areas which were (i) sandy and of high permeability; (ii) in close proximity to rivers; and/or (iii) in close proximity to ponds. Such changes are attributed to monsoonal-driven surface-groundwater interactions and are consistent with the separate provenance of recharge sources as identified using stable isotope mixing models. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  14. DETECTION OF GROUNDWATER AGES WITH 85 KR IN ARSENIC-BEARING, FRACTURED CRYSTALLINE BEDROCK OF THE GOOSE RIVER BASIN, MAINE

    Science.gov (United States)

    Young groundwater from various depths in crystalline bedrock of the Goose River basin, mid-coastal Maine, is documented from 85Kr isotope age analyses (1963 ? 1987) but not from 3H isotope age analyses. Elevated geogenic arsenic in drinking water from groundwater wells and sprin...

  15. Point bars as stratigraphic traps for arsenic contamination in groundwater: Case study of the Ganges River, Bihar, India (abstract)

    NARCIS (Netherlands)

    Donselaar, M.E.; Bhatt, A.G.; Bruining, J.; Bose, N.; Ghosh, A.K.

    2013-01-01

    Arsenic-contaminated groundwater causes a wide-spread, serious health risk affecting millions of people worldwide. Focus of the research is the floodplain of the Ganges River in the State of Bihar (India) where groundwater is the principal source of drinking water and irrigation, and where the

  16. Point bars as stratigraphic traps for arsenic contamination in groundwater: Case study of the Ganges River, Bihar, India (abstract)

    NARCIS (Netherlands)

    Donselaar, M.E.; Bhatt, A.G.; Bruining, J.; Bose, N.; Ghosh, A.K.

    2013-01-01

    Arsenic-contaminated groundwater causes a wide-spread, serious health risk affecting millions of people worldwide. Focus of the research is the floodplain of the Ganges River in the State of Bihar (India) where groundwater is the principal source of drinking water and irrigation, and where the level

  17. Arsenic contamination of groundwater in the Terai region of Nepal: an overview of health concerns and treatment options.

    Science.gov (United States)

    Pokhrel, D; Bhandari, B S; Viraraghavan, T

    2009-01-01

    A review of published information on the arsenic contamination of groundwater in the Terai regions of Nepal showed that the source was mainly geogenic due to the dissolution of the arsenic-bearing minerals. Clinical observations of patients in the arsenic affected districts revealed chronic arsenic poisoning from drinking water. Half a million people inhabiting the region are believed to have been exposed to arsenic levels greater than 50 microg/L in their drinking water. Thirty-one percent of the population (3.5 million) in the region are estimated to have been exposed to arsenic levels between 10 and 50 microg/L. Iron assisted biosand filters currently distributed and in operation are a suitable alternative to mitigate the interim arsenic standard of 50 microg/L, as set by the Nepal Government. Arsenic biosand filters were also effective in removing bacteria and viruses from drinking water in laboratory and field tests. However, groundwater treatment targeting cluster communities in the Terai region is the sustainable way of mitigating the arsenic problem.

  18. Inverse geochemical modeling of groundwater evolution with emphasis on arsenic in the Mississippi River Valley alluvial aquifer, Arkansas (USA)

    Science.gov (United States)

    Sharif, M.U.; Davis, R.K.; Steele, K.F.; Kim, B.; Kresse, T.M.; Fazio, J.A.

    2008-01-01

    Inverse geochemical modeling (PHREEQC) was used to identify the evolution of groundwater with emphasis on arsenic (As) release under reducing conditions in the shallow (25-30 m) Mississippi River Valley Alluvial aquifer, Arkansas, USA. The modeling was based on flow paths defined by high-precision (??2 cm) water level contour map; X-ray diffraction (XRD), scanning electron microscopic (SEM), and chemical analysis of boring-sediments for minerals; and detailed chemical analysis of groundwater along the flow paths. Potential phases were constrained using general trends in chemical analyses data of groundwater and sediments, and saturation indices data (MINTEQA2) of minerals in groundwater. Modeling results show that calcite, halite, fluorite, Fe oxyhydroxide, organic matter, H2S (gas) were dissolving with mole transfers of 1.40E - 03, 2.13E - 04, 4.15E - 06, 1.25E + 01, 3.11, and 9.34, respectively along the dominant flow line. Along the same flow line, FeS, siderite, and vivianite were precipitating with mole transfers of 9.34, 3.11, and 2.64E - 07, respectively. Cation exchange reactions of Ca2+ (4.93E - 04 mol) for Na+ (2.51E - 04 mol) on exchange sites occurred along the dominant flow line. Gypsum dissolution reactions were dominant over calcite dissolution in some of the flow lines due to the common ion effect. The concentration of As in groundwater ranged from modeling indicate that reductive dissolution of Fe oxyhydroxide is the dominant process of As release in the groundwater. The relative rate of reduction of Fe oxyhydroxide over SO42 - with co-precipitation of As into sulfide is the limiting factor controlling dissolved As in groundwater. ?? 2007 Elsevier B.V. All rights reserved.

  19. Contrasting distributions of groundwater arsenic and uranium in the western Hetao basin, Inner Mongolia: Implication for origins and fate controls

    Science.gov (United States)

    Guo, Huaming; Jia, Yongfeng; Wanty, Richard B.; Jiang, Yuxiao; Zhao, Weiguang; Xiu, Wei; Shen, Jiaxing; Li, Yuan; Cao, Yongsheng; Wu, Yang; Zhang, Di; Wei, Chao; Zhang, Yilong; Cao, Wengeng; Foster, Andrea L.

    2016-01-01

    Although As concentrations have been investigated in shallow groundwater from the Hetao basin, China, less is known about U and As distributions in deep groundwater, which would help to better understand their origins and fate controls. Two hundred and ninety-nine groundwater samples, 122 sediment samples, and 14 rock samples were taken from the northwest portion of the Hetao basin, and analyzed for geochemical parameters. Results showed contrasting distributions of groundwater U and As, with high U and low As concentrations in the alluvial fans along the basin margins, and low U and high As concentrations downgradient in the flat plain. The probable sources of both As and U in groundwater were ultimately traced to the bedrocks in the local mountains (the Langshan Mountains). Chemical weathering of U-bearing rocks (schist, phyllite, and carbonate veins) released and mobilized U as UO2(CO3)22 − and UO2(CO3)34 − species in the alluvial fans under oxic conditions and suboxic conditions where reductions of Mn and NO3− were favorable (OSO), resulting in high groundwater U concentrations. Conversely, the recent weathering of As-bearing rocks (schist, phyllite, and sulfides) led to the formation of As-bearing Fe(III) (hydr)oxides in sediments, resulting in low groundwater As concentrations. Arsenic mobilization and U immobilization occurred in suboxic conditions where reduction of Fe(III) oxides was favorable and reducing conditions (SOR). Reduction of As-bearing Fe(III) (hydr)oxides, which were formed during palaeo-weathering and transported and deposited as Quaternary aquifer sediments, was believed to release As into groundwater. Reduction of U(VI) to U(IV) would lead to the formation of uraninite, and therefore remove U from groundwater. We conclude that the contrasting distributions of groundwater As and U present a challenge to ensuring safe drinking water in analogous areas, especially with high background values of U and As.

  20. Vulnerability of deep groundwater in the Bengal Aquifer System to contamination by arsenic

    Science.gov (United States)

    Burgess, W.G.; Hoque, M.A.; Michael, H.A.; Voss, C.I.; Breit, G.N.; Ahmed, K.M.

    2010-01-01

    Shallow groundwater, the primary water source in the Bengal Basin, contains up to 100 times the World Health Organization (WHO) drinking-water guideline of 10g l 1 arsenic (As), threatening the health of 70 million people. Groundwater from a depth greater than 150m, which almost uniformly meets the WHO guideline, has become the preferred alternative source. The vulnerability of deep wells to contamination by As is governed by the geometry of induced groundwater flow paths and the geochemical conditions encountered between the shallow and deep regions of the aquifer. Stratification of flow separates deep groundwater from shallow sources of As in some areas. Oxidized sediments also protect deep groundwater through the ability of ferric oxyhydroxides to adsorb As. Basin-scale groundwater flow modelling suggests that, over large regions, deep hand-pumped wells for domestic supply may be secure against As invasion for hundreds of years. By contrast, widespread deep irrigation pumping might effectively eliminate deep groundwater as an As-free resource within decades. Finer-scale models, incorporating spatial heterogeneity, are needed to investigate the security of deep municipal abstraction at specific urban locations. ?? 2010 Macmillan Publishers Limited. All rights reserved.

  1. Reconnaissance Survey of Arsenic Concentration in Ground-water ...

    African Journals Online (AJOL)

    komla

    groundwater occurrence in this hydro-geological province is also controlled ..... near-neutral pH values make the ore reduced according to Eq. (2), and contribute to the release of the ... Therefore, if a particular brand of fertilizer or pesticide in.

  2. Humic substances and the biogeochemical arsenic cycle in groundwater of the Blackfoot Disease endemic area, southwestern Taiwan

    Science.gov (United States)

    Kulp, T. R.; Jean, J.

    2009-12-01

    Blackfoot Disease (BFD) is a peripheral vascular disease that is endemic to the Chianan Plain area on the southwestern coast of Taiwan. The disease has been linked to long term ingestion of arsenic-contaminated groundwater derived from deep (>100 m) wells that were drilled in the region during the early 1900’s. Victims of BFD typically exhibit symptoms that include ulceration and gangrene in the extremities, which are unique compared to cases of arsenic toxicosis arising in other As-impacted areas. While the exact etiology of BFD is still a subject of some debate, many workers suggest that elevated arsenic in combination with high concentrations of dissolved fluorescent humic compounds in the region’s groundwater are primary causative factors. Despite considerable research over the past 30 years into the occurrence and distribution of As in the region’s groundwater, few studies have been conducted to investigate the geochemical and microbiological processes that influence the element’s speciation and mobility in this aquifer. We measured the concentration and speciation of As associated with sediments and groundwater from wells drilled in the BFD endemic area and conducted sediment microcosm bioassays to investigate the potential for reductive desorption and mobilization of As from the aquifer sediments by endogenous populations of As(V)-reducing bacteria. Samples from 100 -120 m depth were characterized by the highest As concentrations in sediment (1.4 mg/kg) and water (175.4 μg/L). Sediment-adsorbed As was present primarily as As(V) (>87%), whereas ground water samples contained no measurable aqueous As(V). Instead, arsenic in the groundwater samples was present in organo-arsenic complexes and was detectable by hydride generation - atomic absorption spectrophotometry only after oxidative treatments to convert all As to As(V). Biological As(V) reduction was observed in live slurries of aquifer sediment from 120 and 140 m sediment depth. Microbial As

  3. Paper-Based Microfluidic Device with a Gold Nanosensor to Detect Arsenic Contamination of Groundwater in Bangladesh

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    Mosfera A. Chowdury

    2017-03-01

    Full Text Available In this paper, we present a microfluidic paper-based analytical device (μPAD with a gold nanosensor functionalized with α-lipoic acid and thioguanine (Au–TA–TG to detect whether the arsenic level of groundwater from hand tubewells in Bangladesh is above or below the World Health Organization (WHO guideline level of 10 μg/L. We analyzed the naturally occurring metals present in Bangladesh groundwater and assessed the interference with the gold nanosensor. A method was developed to prevent interference from alkaline metals found in Bangladesh groundwater (Ca, Mg, K and Na by increasing the pH level on the μPADs to 12.1. Most of the heavy metals present in the groundwater (Ni, Mn, Cd, Pb, and Fe II did not interfere with the μPAD arsenic tests; however, Fe III was found to interfere, which was also prevented by increasing the pH level on the μPADs to 12.1. The μPAD arsenic tests were tested with 24 groundwater samples collected from hand tubewells in three different districts in Bangladesh: Shirajganj, Manikganj, and Munshiganj, and the predictions for whether the arsenic levels were above or below the WHO guideline level agreed with the results obtained from laboratory testing. The μPAD arsenic test is the first paper-based test validated using Bangladesh groundwater samples and capable of detecting whether the arsenic level in groundwater is above or below the WHO guideline level of 10 μg/L, which is a step towards enabling the villagers who collect and consume the groundwater to test their own sources and make decisions about where to obtain the safest water.

  4. Pilot study on arsenic removal from groundwater using a small-scale reverse osmosis system-Towards sustainable drinking water production.

    Science.gov (United States)

    Schmidt, Stefan-André; Gukelberger, Ephraim; Hermann, Mario; Fiedler, Florian; Großmann, Benjamin; Hoinkis, Jan; Ghosh, Ashok; Chatterjee, Debashis; Bundschuh, Jochen

    2016-11-15

    Arsenic contamination of groundwater is posing a serious challenge to drinking water supplies on a global scale. In India and Bangladesh, arsenic has caused the most serious public health issue in the world for nearly two decades. The aim of this work was to study an arsenic removal system based on reverse osmosis at pilot scale treating two different water sources from two different locations in the State of Bihar, India. For this purpose two villages, Bind Toli and Ramnagar in the Patna District were selected, both located very close to the river Ganga. The trials were conducted with aerated and non-aerated groundwater. It is the first time that the arsenic removal efficiency for aerated and non-aerated groundwater by reverse osmosis technology in combination with an energy-saving recovery system have been studied. As the principle of reverse osmosis requires a relatively high pressure, its energy demand is naturally high. By using an energy recovery system, this demand can be lowered, leading to an energy demand per liter permeate of 3-4Wh/L only. Due to high iron levels in the groundwater and as a consequence the precipitation of ferric (hydr)oxides, it was necessary to develop a granular media filter for the trials under aeration in order to protect the membrane from clogging. Two different materials, first locally available sand, and second commercially available anthracite were tested in the granular media filter. For the trials with aerated groundwater, total arsenic removal efficiency at both locations was around 99% and the arsenic concentration in permeate was in compliance with the WHO and National Indian Standard of 10μg/L. However, trials under anoxic conditions with non-aerated groundwater could not comply with this standard. Additionally a possible safe discharge of the reverse osmosis concentrate into an abandoned well was studied. It was observed that re-injection of reject water underground may offer a safe disposal option. However, long

  5. Arsenic

    Science.gov (United States)

    Arsenic is a natural element found in soil and minerals. Arsenic compounds are used to preserve wood, as pesticides, and in some industries. Arsenic can get into air, water, and the ground from wind- ...

  6. Hydrogeochemistry of Groundwater and Arsenic Adsorption Characteristics of Subsurface Sediments in an Alluvial Plain, SW Taiwan

    Directory of Open Access Journals (Sweden)

    Libing Liao

    2016-12-01

    Full Text Available Many studies were conducted to investigate arsenic mobilization in different alluvial plains worldwide. However, due to the unique endemic disease associated with arsenic (As contamination in Taiwan, a recent research was re-initiated to understand the transport behavior of arsenic in a localized alluvial plain. A comprehensive approach towards arsenic mobility, binding, and chemical speciation was applied to correlate groundwater hydrogeochemistry with parameters of the sediments that affected the As fate and transport. The groundwater belongs to a Na-Ca-HCO3 type with moderate reducing to oxidizing conditions (redox potential = −192 to 8 mV. Groundwater As concentration in the region ranged from 8.89 to 1131 μg/L with a mean of 343 ± 297 μg/L, while the As content in the core sediments varied from 0.80 to 22.8 mg/kg with a mean of 9.9 ± 6.2 mg/kg. A significant correlation was found between As and Fe, Mn, or organic matter, as well as other elements such as Ni, Cu, Zn, and Co in the core sediments. Sequential extraction analysis indicated that the organic matter and Fe/Mn oxyhydroxides were the major binding pools of As. Batch adsorption experiments showed that the sediments had slightly higher affinity for As(III than for As(V under near neutral pH conditions and the As adsorption capacity increased as the contents of Fe oxyhydroxides as well as the organic matter increased.

  7. Groundwater arsenic removal using granular TiO2: integrated laboratory and field study.

    Science.gov (United States)

    Cui, Jinli; Du, Jingjing; Yu, Siwu; Jing, Chuanyong; Chan, Tingshan

    2015-06-01

    High concentrations of arsenic (As) in groundwater pose a great threat to human health. The motivation of this study was to provide a practical solution for As-safe water in As geogenic areas using granular TiO2 (GTiO2). The kinetics results indicated that the As (III/V) adsorption on GTiO2 conformed to the Weber-Morris (WM) intraparticle diffusion model. The Langmuir isotherm results suggested that the adsorption capacities for As (III) and As (V) were 106.4 and 38.3 mg/g, respectively. Ion effect study showed that cationic Ca and Mg substantially enhanced As (V) adsorption, whereas no significant impact was observed on As (III). Silicate substantially decreased As (V) adsorption by 57 % and As (III) by 50 %. HCO3 (-) remarkably inhibited As (V) adsorption by 52 %, whereas it slightly reduced As (III) adsorption by 8 %. Field column results demonstrated that ∼700 μg/L As was removed at an empty bed contact time (EBCT) of 1.08 min for 968 bed volumes before effluent As concentration exceeded 10 μg/L, corresponding to 0.96 mg As/g GTiO2. Two household filters loaded with 110 g GTiO2 in the on-off operational mode can provide 6-L/day As-safe drinking water up to 288 and 600 days from the groundwater containing ∼700 μg/L As and ∼217 μg/L As, respectively. Integration of batch experiments and column tests with systematic variation of EBCTs was successfully achieved using PHREEQC incorporating a charge distribution multisite complexation (CD-MUSIC) model and one-dimensional reactive transport block.

  8. Binational Arsenic Exposure Survey: Methodology and Estimated Arsenic Intake from Drinking Water and Urinary Arsenic Concentrations

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    Robin B. Harris

    2012-03-01

    Full Text Available The Binational Arsenic Exposure Survey (BAsES was designed to evaluate probable arsenic exposures in selected areas of southern Arizona and northern Mexico, two regions with known elevated levels of arsenic in groundwater reserves. This paper describes the methodology of BAsES and the relationship between estimated arsenic intake from beverages and arsenic output in urine. Households from eight communities were selected for their varying groundwater arsenic concentrations in Arizona, USA and Sonora, Mexico. Adults responded to questionnaires and provided dietary information. A first morning urine void and water from all household drinking sources were collected. Associations between urinary arsenic concentration (total, organic, inorganic and estimated level of arsenic consumed from water and other beverages were evaluated through crude associations and by random effects models. Median estimated total arsenic intake from beverages among participants from Arizona communities ranged from 1.7 to 14.1 µg/day compared to 0.6 to 3.4 µg/day among those from Mexico communities. In contrast, median urinary inorganic arsenic concentrations were greatest among participants from Hermosillo, Mexico (6.2 µg/L whereas a high of 2.0 µg/L was found among participants from Ajo, Arizona. Estimated arsenic intake from drinking water was associated with urinary total arsenic concentration (p < 0.001, urinary inorganic arsenic concentration (p < 0.001, and urinary sum of species (p < 0.001. Urinary arsenic concentrations increased between 7% and 12% for each one percent increase in arsenic consumed from drinking water. Variability in arsenic intake from beverages and urinary arsenic output yielded counter intuitive results. Estimated intake of arsenic from all beverages was greatest among Arizonans yet participants in Mexico had higher urinary total and inorganic arsenic concentrations. Other contributors to urinary arsenic concentrations should be evaluated.

  9. Binational arsenic exposure survey: methodology and estimated arsenic intake from drinking water and urinary arsenic concentrations.

    Science.gov (United States)

    Roberge, Jason; O'Rourke, Mary Kay; Meza-Montenegro, Maria Mercedes; Gutiérrez-Millán, Luis Enrique; Burgess, Jefferey L; Harris, Robin B

    2012-04-01

    The Binational Arsenic Exposure Survey (BAsES) was designed to evaluate probable arsenic exposures in selected areas of southern Arizona and northern Mexico, two regions with known elevated levels of arsenic in groundwater reserves. This paper describes the methodology of BAsES and the relationship between estimated arsenic intake from beverages and arsenic output in urine. Households from eight communities were selected for their varying groundwater arsenic concentrations in Arizona, USA and Sonora, Mexico. Adults responded to questionnaires and provided dietary information. A first morning urine void and water from all household drinking sources were collected. Associations between urinary arsenic concentration (total, organic, inorganic) and estimated level of arsenic consumed from water and other beverages were evaluated through crude associations and by random effects models. Median estimated total arsenic intake from beverages among participants from Arizona communities ranged from 1.7 to 14.1 µg/day compared to 0.6 to 3.4 µg/day among those from Mexico communities. In contrast, median urinary inorganic arsenic concentrations were greatest among participants from Hermosillo, Mexico (6.2 µg/L) whereas a high of 2.0 µg/L was found among participants from Ajo, Arizona. Estimated arsenic intake from drinking water was associated with urinary total arsenic concentration (p < 0.001), urinary inorganic arsenic concentration (p < 0.001), and urinary sum of species (p < 0.001). Urinary arsenic concentrations increased between 7% and 12% for each one percent increase in arsenic consumed from drinking water. Variability in arsenic intake from beverages and urinary arsenic output yielded counter intuitive results. Estimated intake of arsenic from all beverages was greatest among Arizonans yet participants in Mexico had higher urinary total and inorganic arsenic concentrations. Other contributors to urinary arsenic concentrations should be evaluated.

  10. Geochemistry and mineralogy of arsenic in (natural) anaerobic groundwaters

    Energy Technology Data Exchange (ETDEWEB)

    Saunders, J.A. [Department of Geology and Geography, Auburn University, Auburn, AL (United States)], E-mail: saundja@auburn.edu; Lee, M.-K.; Shamsudduha, M.; Dhakal, P.; Uddin, A. [Department of Geology and Geography, Auburn University, Auburn, AL (United States); Chowdury, M.T.; Ahmed, K.M. [Department of Geology, University of Dhaka, Dhaka (Bangladesh)

    2008-11-15

    Here new data from field bioremediation experiments and geochemical modeling are reported to illustrate the principal geochemical behavior of As in anaerobic groundwaters. In the field bioremediation experiments, groundwater in Holocene alluvial aquifers in Bangladesh was amended with labile water-soluble organic C (molasses) and MgSO{sub 4} to stimulate metabolism of indigenous SO{sub 4}-reducing bacteria (SRB). In the USA, the groundwater was contaminated by Zn, Cd and SO{sub 4}, and contained <10 {mu}g/L As under oxidized conditions, and a mixture of sucrose and methanol were injected to stimulate SRB metabolism. In Bangladesh, groundwater was under moderately reducing conditions and contained {approx}10 mg/L Fe and {approx}100 {mu}g/L As. In the USA experiment, groundwater rapidly became anaerobic, and dissolved Fe and As increased dramatically (As > 1000 {mu}g/L) under geochemical conditions consistent with bacterial Fe-reducing conditions. With time, groundwater became more reducing and biogenic SO{sub 4} reduction began, and Cd and Zn were virtually completely removed due to precipitation of sphalerite (ZnS) and other metal sulfide mineral(s). Following precipitation of chalcophile elements Zn and Cd, the concentrations of Fe and As both began to decrease in groundwater, presumably due to formation of As-bearing FeS/FeS{sub 2}. By the end of the six-month experiment, dissolved As had returned to below background levels. In the initial Bangladesh experiment, As decreased to virtually zero once biogenic SO{sub 4} reduction commenced but increased to pre-experiment level once SO{sub 4} reduction ended. In the ongoing experiment, both SO{sub 4} and Fe(II) were amended to groundwater to evaluate if FeS/FeS{sub 2} formation causes longer-lived As removal. Because As-bearing pyrite is the common product of SRB metabolism in Holocene alluvial aquifers in both the USA and Southeast Asia, it was endeavored to derive thermodynamic data for arsenian pyrite to better

  11. Arsenic species in broiler (Gallus gallus domesticus) litter, soils, maize (Zea mays L.), and groundwater from litter-amended fields.

    Science.gov (United States)

    D'Angelo, Elisa; Zeigler, Georgia; Beck, E Glenn; Grove, John; Sikora, Frank

    2012-11-01

    Manure and bedding material (litter) generated by the broiler industry (Gallus gallus domesticus) often contain high levels of arsenic (As) when organoarsenical roxarsone and p-arsanilic acid are included in feed to combat disease and improve weight gain of the birds. This study was conducted to determine As levels and species in litter from three major broiler producing companies, and As levels in soils, corn tissue (Zea mays L.), and groundwater in fields where litter was applied. Total As in litter from the three different integrators ranged between bioavailable As (extractable with Mehlich 3 solution and taken up by corn leaves). Arsenic concentrations in plant tissue and groundwater, however, were below the World Health Organization thresholds, which was attributed to strong sorption/precipitation of arsenate in Fe- and Al-rich soils. Ecological impacts of amending soils with As-laden litter depend on the As species in the litter, and chemical and physical properties of soil that strongly affect As mobility and bioavailability in the environment. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Genetic integrity of the human Y chromosome exposed to groundwater arsenic

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    Ali Sher

    2010-08-01

    Full Text Available Abstract Background Arsenic is a known human carcinogen reported to cause chromosomal deletions and genetic anomalies in cultured cells. The vast human population inhabiting the Ganges delta in West Bengal, India and Bangladesh is exposed to critical levels of arsenic present in the groundwater. The genetic and physiological mechanism of arsenic toxicity in the human body is yet to be fully established. In addition, lack of animal models has made work on this line even more challenging. Methods Human male blood samples were collected with their informed consent from 5 districts in West Bengal having groundwater arsenic level more than 50 μg/L. Isolation of genomic DNA and preparation of metaphase chromosomes was done using standard protocols. End point PCR was performed for established sequence tagged sites to ascertain the status of recombination events. Single nucleotide variants of candidate genes and amplicons were carried out using appropriate restriction enzymes. The copy number of DYZ1 array per haploid genome was calculated using real time PCR and its chromosomal localization was done by fluorescence in-situ hybridization (FISH. Results We studied effects of arsenic exposure on the human Y chromosome in males from different areas of West Bengal focusing on known recombination events (P5-P1 proximal; P5-P1 distal; gr/gr; TSPY-TSPY, b1/b3 and b2/b3, single nucleotide variants (SNVs of a few candidate Y-linked genes (DAZ, TTY4, BPY2, GOLGA2LY and the amplicons of AZFc region. Also, possible chromosomal reorganization of DYZ1 repeat arrays was analyzed. Barring a few microdeletions, no major changes were detected in blood DNA samples. SNV analysis showed a difference in some alleles. Similarly, DYZ1 arrays signals detected by FISH were found to be affected in some males. Conclusions Our Y chromosome analysis suggests that the same is protected from the effects of arsenic by some unknown mechanisms maintaining its structural and functional

  13. Genesis of arsenic-rich groundwater and the search for alternative safe aquifers in the Gangetic Plain, India.

    Science.gov (United States)

    Saha, Dipankar; Shukla, R R

    2013-12-01

    Distribution and mobilization of groundwater arsenic from a 1580-km(2) area in the Gangetic Plain was studied. A two-tier aquifer system made up of Quaternary sand layers exists within 300 m below ground. Arsenic concentration exceeding >50 microg/L is confined within the active floodplain of the Ganga River, affecting the top aquitard and upper 5- to 20-m slice of the underlying shallow aquifer. The genesis of arsenic was investigated by principal component analyses involving total dissolved solids, Ca(+2), Mg(+2), Na(+), K(+), HCO3-, Cl(-1), SO4(-2), NO3-, Fetotal, and Astotal and analyzed for 57 groundwater samples, hydrochemical facies analyses, aquifer-aquitard configuration, and water-level behaviour. A 20- to 25-m thick deeper aquifer, appearing at 190 to 205 m below ground and separated from the shallow aquifer by a thick clay sequence, was low in arsenic load (aquifer can be used for community drinking in contaminated areas.

  14. Spatial Analysis of Human Health Risk Due to Arsenic Exposure through Drinking Groundwater in Taiwan’s Pingtung Plain

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    Ching-Ping Liang

    2017-01-01

    Full Text Available Chronic arsenic (As exposure continues to be a public health problem of major concern worldwide, affecting hundreds of millions of people. A long-term groundwater quality survey has revealed that 20% of the groundwater in southern Taiwan’s Pingtung Plain is clearly contaminated with a measured As concentration in excess of the maximum level of 10 µg/L recommended by the World Health Organization. The situation is further complicated by the fact that more than half of the inhabitants in this area continue to use groundwater for drinking. Efforts to assess the health risk associated with the ingestion of As from the contaminated drinking water are required in order to determine the priorities for health risk management. The conventional approach to conducting a human health risk assessment may be insufficient for this purpose, so this study adopts a geostatistical Kriging method to perform a spatial analysis of the health risk associated with ingesting As through drinking groundwater in the Pingtung Plain. The health risk is assessed based on the hazard quotient (HQ and target cancer risk (TR established by the U.S. Environmental Protection Agency. The results show that most areas where the HQ exceeds 1 are in the southwestern part of the study area. In addition, the high-population density townships of Daliao, Linyuan, Donggang, Linbian, Jiadong, and Fangliao presently have exceedingly high TR values that are two orders of magnitude higher than the acceptable standard. Thus, the use of groundwater for drinking in these townships should be strictly avoided. A map that delineates areas with high TR values and high population densities is provided. The findings broaden the scope of the spatial analysis of human health risk and provide a basis for improving the decision-making process.

  15. Spatial Analysis of Human Health Risk Due to Arsenic Exposure through Drinking Groundwater in Taiwan’s Pingtung Plain

    Science.gov (United States)

    Liang, Ching-Ping; Chien, Yi-Chi; Jang, Cheng-Shin; Chen, Ching-Fang; Chen, Jui-Sheng

    2017-01-01

    Chronic arsenic (As) exposure continues to be a public health problem of major concern worldwide, affecting hundreds of millions of people. A long-term groundwater quality survey has revealed that 20% of the groundwater in southern Taiwan’s Pingtung Plain is clearly contaminated with a measured As concentration in excess of the maximum level of 10 µg/L recommended by the World Health Organization. The situation is further complicated by the fact that more than half of the inhabitants in this area continue to use groundwater for drinking. Efforts to assess the health risk associated with the ingestion of As from the contaminated drinking water are required in order to determine the priorities for health risk management. The conventional approach to conducting a human health risk assessment may be insufficient for this purpose, so this study adopts a geostatistical Kriging method to perform a spatial analysis of the health risk associated with ingesting As through drinking groundwater in the Pingtung Plain. The health risk is assessed based on the hazard quotient (HQ) and target cancer risk (TR) established by the U.S. Environmental Protection Agency. The results show that most areas where the HQ exceeds 1 are in the southwestern part of the study area. In addition, the high-population density townships of Daliao, Linyuan, Donggang, Linbian, Jiadong, and Fangliao presently have exceedingly high TR values that are two orders of magnitude higher than the acceptable standard. Thus, the use of groundwater for drinking in these townships should be strictly avoided. A map that delineates areas with high TR values and high population densities is provided. The findings broaden the scope of the spatial analysis of human health risk and provide a basis for improving the decision-making process. PMID:28098817

  16. Spatial Analysis of Human Health Risk Due to Arsenic Exposure through Drinking Groundwater in Taiwan's Pingtung Plain.

    Science.gov (United States)

    Liang, Ching-Ping; Chien, Yi-Chi; Jang, Cheng-Shin; Chen, Ching-Fang; Chen, Jui-Sheng

    2017-01-14

    Chronic arsenic (As) exposure continues to be a public health problem of major concern worldwide, affecting hundreds of millions of people. A long-term groundwater quality survey has revealed that 20% of the groundwater in southern Taiwan's Pingtung Plain is clearly contaminated with a measured As concentration in excess of the maximum level of 10 µg/L recommended by the World Health Organization. The situation is further complicated by the fact that more than half of the inhabitants in this area continue to use groundwater for drinking. Efforts to assess the health risk associated with the ingestion of As from the contaminated drinking water are required in order to determine the priorities for health risk management. The conventional approach to conducting a human health risk assessment may be insufficient for this purpose, so this study adopts a geostatistical Kriging method to perform a spatial analysis of the health risk associated with ingesting As through drinking groundwater in the Pingtung Plain. The health risk is assessed based on the hazard quotient (HQ) and target cancer risk (TR) established by the U.S. Environmental Protection Agency. The results show that most areas where the HQ exceeds 1 are in the southwestern part of the study area. In addition, the high-population density townships of Daliao, Linyuan, Donggang, Linbian, Jiadong, and Fangliao presently have exceedingly high TR values that are two orders of magnitude higher than the acceptable standard. Thus, the use of groundwater for drinking in these townships should be strictly avoided. A map that delineates areas with high TR values and high population densities is provided. The findings broaden the scope of the spatial analysis of human health risk and provide a basis for improving the decision-making process.

  17. Arsenic removal from groundwater using iron electrocoagulation: effect of charge dosage rate.

    Science.gov (United States)

    Amrose, Susan; Gadgil, Ashok; Srinivasan, Venkat; Kowolik, Kristin; Muller, Marc; Huang, Jessica; Kostecki, Robert

    2013-01-01

    We demonstrate that electrocoagulation (EC) using iron electrodes can reduce arsenic below 10 μg/L in synthetic Bangladesh groundwater and in real groundwater from Bangladesh and Cambodia, while investigating the effect of operating parameters that are often overlooked, such as charge dosage rate. We measure arsenic removal performance over a larger range of current density than in any other single previous EC study (5000-fold: 0.02 - 100 mA/cm(2)) and over a wide range of charge dosage rates (0.060 - 18 Coulombs/L/min). We find that charge dosage rate has significant effects on both removal capacity (μg-As removed/Coulomb) and treatment time and is the appropriate parameter to maintain performance when scaling to different active areas and volumes. We estimate the operating costs of EC treatment in Bangladesh groundwater to be $0.22/m(3). Waste sludge (~80 - 120 mg/L), when tested with the Toxic Characteristic Leachate Protocol (TCLP), is characterized as non-hazardous. Although our focus is on developing a practical device, our results suggest that As[III] is mostly oxidized via a chemical pathway and does not rely on processes occurring at the anode. Supplementary materials are available for this article. Go to the publisher's online edition of Journal of Environmental Science and Health, Part A, to view the free supplemental file.

  18. Human exposure to arsenic in groundwater from Lahore district, Pakistan.

    Science.gov (United States)

    Bibi, Mehwish; Hashmi, Muhammad Zaffar; Malik, Riffat Naseem

    2015-01-01

    In the present study we determined As concentrations in healthy volunteers from three different age groups (children, adults and old age) residing in Lahore, Pakistan to gain insight into arsenic exposure to humans via drinking water. The results revealed that the concentrations of As were significantly (p<0.05) different among different sites, while non significant trends were observed among different age classes. As concentrations in blood and nails samples showed a significant (p<0.05) positive correlation. The mean concentrations of As were higher in nails samples (1.43μg/g) followed by blood samples (1.15μg/L); urine samples (0.82μg/l) and hair samples (0.74μg/g) based on all sites. The antioxidants enzyme activities in blood samples showed a significant (p<0.01) decrease with the increase in As concentrations. The result suggests that urgent action is needed to prevent further human exposure to As.

  19. Unraveling Health Risk and Speciation of Arsenic from Groundwater in Rural Areas of Punjab, Pakistan

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    Muhammad Bilal Shakoor

    2015-10-01

    Full Text Available This study determined the total and speciated arsenic (As concentrations and other health-related water quality parameters for unraveling the health risk of As from drinking water to humans. Groundwater samples (n = 62 were collected from three previously unexplored rural areas (Chichawatni, Vehari, Rahim Yar Khan of Punjab in Pakistan. The mean and median As concentrations in groundwater were 37.9 and 12.7 µg·L−1 (range = 1.5–201 µg·L−1. Fifty three percent groundwater samples showed higher As value than WHO safe limit of 10 µg·L−1. Speciation of As in groundwater samples (n = 13 showed the presence of inorganic As only; arsenite (As(III constituted 13%–67% of total As and arsenate (As(V ranged from 33% to 100%. For As health risk assessment, the hazard quotient and cancer risk values were 11–18 and 46–600 times higher than the recommended values of US-EPA (i.e., 1.00 and 10−6, respectively. In addition to As, various water quality parameters (e.g., electrical conductivity, Na, Ca, Cl−, NO3−, SO42−, Fe, Mn, Pb also enhanced the health risk. The results show that consumption of As-contaminated groundwater poses an emerging health threat to the communities in the study area, and hence needs urgent remedial and management measures.

  20. Unraveling Health Risk and Speciation of Arsenic from Groundwater in Rural Areas of Punjab, Pakistan

    Science.gov (United States)

    Shakoor, Muhammad Bilal; Niazi, Nabeel Khan; Bibi, Irshad; Rahman, Mohammad Mahmudur; Naidu, Ravi; Dong, Zhaomin; Shahid, Muhammad; Arshad, Muhammad

    2015-01-01

    This study determined the total and speciated arsenic (As) concentrations and other health-related water quality parameters for unraveling the health risk of As from drinking water to humans. Groundwater samples (n = 62) were collected from three previously unexplored rural areas (Chichawatni, Vehari, Rahim Yar Khan) of Punjab in Pakistan. The mean and median As concentrations in groundwater were 37.9 and 12.7 µg·L−1 (range = 1.5–201 µg·L−1). Fifty three percent groundwater samples showed higher As value than WHO safe limit of 10 µg·L−1. Speciation of As in groundwater samples (n = 13) showed the presence of inorganic As only; arsenite (As(III)) constituted 13%–67% of total As and arsenate (As(V)) ranged from 33% to 100%. For As health risk assessment, the hazard quotient and cancer risk values were 11–18 and 46–600 times higher than the recommended values of US-EPA (i.e., 1.00 and 10−6, respectively). In addition to As, various water quality parameters (e.g., electrical conductivity, Na, Ca, Cl−, NO3−, SO42−, Fe, Mn, Pb) also enhanced the health risk. The results show that consumption of As-contaminated groundwater poses an emerging health threat to the communities in the study area, and hence needs urgent remedial and management measures. PMID:26445051

  1. Ultra-high purity arsenic for MBE

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, R.G.L. (Johnson Matthey PLC, Royston (UK)); Emeny, M.T.; Whitehouse, C.R.; Lee, D. (Royal Signals and Radar Ets., Great Malvern (UK))

    1990-11-01

    A requirement for high purity elemental arsenic for use in compound semiconductors has become well established. The capabilities of molecular beam epitaxy as a fabrication technique are best exploited if the arsenic used has particular additional features. Prominent among these are a uniform distribution of impurities at levels down to 10 ppb, and a geometrically uniform distribution of material in the charge used. Once material such as this, of 7N purity or better, emerges from its processing, a major vulernability is from recontamination. Prevention of this is a further important requirement. Detailed examination of possible process strategies has led to an approach targeted on the manufacture of solid arsenic ''charges'' especially suited for MBE application. Factors involved are reviewed. An outline of the consequent production operation is described, based on vapour phase and laser processing. Continuous long-term reproducibility is achieved. Analysis of the product by glow discharge mass spectrometry with state-of-the-art sensitivity is used for qualification of the product and process. Results from this and supplementary techniques which have been used are presented. The utilisation of this material for GaAs has been widely tested successfully. The outcome of some of that work is shown. (orig.).

  2. Effect on Groundwater Quality from Proximal Surface Water Bodies and Effect on Arsenic Distribution in Bangladesh: Geochemical Controls

    Science.gov (United States)

    Barua, S.; Kulkarni, H.; Mladenov, N.; Khan, M. A.; Mahfuz, M.; Ahmed, K. M.; Datta, S.

    2014-12-01

    Matlab is one of the areas in SE Bangladesh highly affected with elevated concentrations of dissolved As in drinking waters. Matlab is stratigraphically composed of thick floodplain deposits of Holocene age overlying Plio-Pleistocene grey fine to coarse sands with considerable clay (Dupi Tila). The dissolved As concentrations in the studied area ranged from detection in shallow well waters (MPN= 3.6-74.1) was high as well as in ponds and canals (MPN= 8.5-433.4). Microbial activity in groundwater was lower than in unprotected surface waters. Freshness index (β:α), humification index (HIX), fluorescence source index (FI) values showed that DOM in shallow and surface water bodies was distinct from deep groundwater. Concurrent with the lower DOC in deeper wells, the overall fluorescence intensities decreased with depth. The results thus far point to more humic DOM in shallow groundwaters, which is not expected to be a labile carbon source for microorganisms, but which may be involved in complexation or other biogeochemical reactions that mobilize arsenic.

  3. Determinants of Arsenicosis Patients’ Perception and Social Implications of Arsenic Poisoning through Groundwater in Bangladesh

    Directory of Open Access Journals (Sweden)

    M. Mizanur Rahman Sarker

    2010-10-01

    Full Text Available Adverse human health effects ranging from skin lesions to internal cancers as well as widespread social and psychological problems caused by arsenic contaminated drinking water in Bangladesh may be the biggest arsenic calamity in the world. From an arsenicosis patients survey, this paper empirically analyzes the determinants of arsenicosis patients’ perception about chronic arsenic poisoning and social and psychological implications of arsenicosis. In this study, cross-sectional data were collected from the Matlab and Hajiganj Upzillas of Chandpur district which are known to be highly contaminated with arsenic in their underground water. Respondents informed that arsenic poisoning causes a wide range of social and psychological problems. Female respondents were less vulnerable in the case of social problems (p < 0.01 and more vulnerable for the psychological problems (p < 0.001 of arsenicosis than male respondents. The results based on logit analysis showed that education (p < 0.01 and household income (p < 0.05 were significantly correlated to respondents’ perception about arsenicosis. The arsenicosis related special program (s needs a clear understanding of people’s perception about arsenic exposure for abating the health burden as well as social and psychological problems.

  4. Sources and controls of Arsenic contamination in groundwater of Rajnandgaon and Kanker District, Chattisgarh Central India

    Science.gov (United States)

    Shukla, Dericks Praise; Dubey, C. S.; Singh, Ningthoujam P.; Tajbakhsh, M.; Chaudhry, M.

    2010-12-01

    SummaryA high concentration of Arsenic (As) contamination in ground water has been reported in the village of Kaudikasa in Rajnandgaon district, wherein around 10% of the population is suffering from As-borne diseases. The region does not share any demographic or geological similarity with the sedimentary aquifers of the Bengal Delta Plain in Eastern India, but represents an igneous terrain with elevated As concentrations in groundwater. There is limited information about the source of As in groundwater and its mobility constraints. In this area, almost all the wells are located in the granitic terrain with pegmatitic intrusions. Most of these wells are characterized by As concentration above the World Health Organization ( WHO, 1999) and the BIS (Bureau of Indian Standards) standards, with the highest being found in a well with more than 250 μg/L of As. Here we report petrographic studies of the granitic host rock and X-ray diffraction results that indicate that altered realgar (α-As 4S 4), para realgar (AsS), and/or tennantite (Cu 12As 4S 13), are the main mineral that contain As. This element is leached during the weathering and water-rock interactions. Microprobe analysis of the altered realgar grains of in pegmatitic intrusions of the host granite indicate 23-27 wt.% As. Remote sensing is useful to delineate the source of this contaminant, which appears to lie at the intersection of a mineralized NW-SE and N-S lineaments associated with the Kotri rift zone. These lineaments are structurally controlled as rifting followed by thrusting and other types of faulting caused left-lateral displacement of N-S Kotri lineament along a NW-SE fault plane showing sinistral shearing. This process caused water drainage in the areas to flow along these highly mineralized weak zones. Thus, the water becomes highly contaminated due to leaching of minerals at the intersection of these lineaments, clearly visible at two areas of high contamination that lie very near to this

  5. The iron, aluminate and jarosite deposits in Riazas area as potential source of arsenic in groundwater; Los yacimientos de hierro, alunita y jarosita de la zona de Riaza como posible origen del arsenico en las aguas subterraneas

    Energy Technology Data Exchange (ETDEWEB)

    Leal Meca, M.; Lilo Ramos, J.

    2009-07-01

    Arsenic in concentrations above the legal limit of 10 {mu}g/l has been detected in groundwaters of the Duero Cenozoic Basin. The origin of arsenic is related to sedimentary units with arsenic content above the background value of 28.5 mg/kg. Thus, iron-rich deposits located at the base of Cenozoic succession may constitute a potential source of arsenic in the groundwaters. Three outcrops of iron-rich conglomerates in the Riazas area of Segovia province (one in El Negredo and two in Madriguera) have been studied to determine the significance of these materials as a potential source of arsenic in groundwater. These outcrops occur above an unconformity separating them from strongly altered Paleozoic slates, rich in alunite and jarosite. The work is based in geochemical (trace elements detection by INAA) and mineralogical analyses (through XRD-EDAX and ESEM) of 18 samples of altered slates and materials of ferriferrous deposits. Besides, 3 water samples from springs have subjected to hydrochemical analysis to establish major ionic species and trace elements. Although mineralogical study reveals that arsenic occurs in iron oxides and high arsenic concentrations have been identified in rocks of El Negredo (up to 361 mg/kg, average 143.3 mg/kg), the arsenic concentrations in Ca-Mg-HCO{sub 3} - water type are always lower than 10 {mu}g/l. Therefore, it does not seem to be probable that these deposits act as arsenic source, at least at the present physic-chemical conditions.(Author) 37 refs.

  6. Simultaneous arsenic and fluoride removal from synthetic and real groundwater by electrocoagulation process: Parametric and cost evaluation.

    Science.gov (United States)

    Thakur, Lokendra Singh; Mondal, Prasenjit

    2017-04-01

    Co-existence of arsenic and fluoride in groundwater has raised severe health issues to living being. Thus, the present research has been conducted for simultaneous removal of arsenic and fluoride from synthetic groundwater by using electrocoagulation process with aluminum electrode. Effects of initial pH, current density, run time, inter electrode distance and NaCl concentration over percentage removal of arsenic and fluoride as well as operating cost have been studied. The optimum experimental conditions are found to be initial pH: 7, current density: 10 A/m(2), run time: 95 min, inter electrode distance: 1 cm, NaCl concentration: 0.71 g/l for removal of 98.51% arsenic (initial concentration: 550 μg/l) and 88.33% fluoride (initial concentration: 12 mg/l). The concentration of arsenic and fluoride in treated water are found to be 8.19 μg/l and 1.4 mg/l, respectively, with an operating cost of 0.357 USD/m(3) treated water. Pseudo first and second order kinetic model of individual and simultaneous arsenic and fluoride removal in electrocoagulation have also been studied. Produced sludge characterization studies also confirm the presence of arsenic in As(III) form, and fluoride in sludge. The present electrocoagulation process is able to reduce the arsenic and fluoride concentration of synthetic as well as real groundwater to below 10 μg/l and 1.5 mg/l, respectively, which are maximum contaminant level of these elements in drinking water according to WHO guidelines. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Source and distribution of naturally occurring arsenic in groundwater from Alberta’s Southern Oil Sands Regions

    Energy Technology Data Exchange (ETDEWEB)

    Moncur, Michael C.; Paktunc, Dogan; Birks, S. Jean; Ptacek, Carol J.; Welsh, Brent; Thibault, Yves (CanmetMINING); (AER); (Alberta Innov.); (Waterloo)

    2016-06-10

    Arsenic (As) concentrations as high as 179 μg/L have been observed in shallow groundwater in the Alberta’s Southern Oil Sand Regions. The geology of this area of Alberta includes a thick cover (up to 200 m) of unconsolidated glacial deposits, with a number of regional interglacial sand and gravel aquifers, underlain by marine shale. Arsenic concentrations observed in 216 unconsolidated sediment samples ranged from 1 and 17 ppm. A survey of over 800 water wells sampled for As in the area found that 50% of the wells contained As concentrations exceeding drinking water guidelines of 10 μg/L. Higher As concentrations in groundwater were associated with reducing conditions. Measurements of As speciation from 175 groundwater samples indicate that As(III) was the dominant species in 74% of the wells. Speciation model calculations showed that the majority of groundwater samples were undersaturated with respect to ferrihydrite, suggesting that reductive dissolution of Fe-oxyhydroxides may be the source of some As in groundwater. Detailed mineralogical characterization of sediment samples collected from two formations revealed the presence of fresh framboidal pyrite in the deeper unoxidized sediments. Electron microprobe analysis employing wavelength dispersive spectrometry indicated that the framboidal pyrite had variable As content with an average As concentration of 530 ppm, reaching up to 1840 ppm. In contrast, the oxidized sediments did not contain framboidal pyrite, but exhibited spheroidal Fe-oxyhydroxide grains with elevated As concentrations. The habit and composition suggest that these Fe-oxyhydroxide grains in the oxidized sediment were an alteration product of former framboidal pyrite grains. X-ray absorption near edge spectroscopy (XANES) indicated that the oxidized sediments are dominated by As(V) species having spectral features similar to those of goethite or ferrihydrite with adsorbed As, suggesting that Fe-oxyhydroxides are the dominant As carriers

  8. Quantitative assessment of possible human health risk associated with consumption of arsenic contaminated groundwater and wheat grains from Ropar Wetand and its environs.

    Science.gov (United States)

    Sharma, Sakshi; Kaur, Jagdeep; Nagpal, Avinash Kaur; Kaur, Inderpreet

    2016-09-01

    Arsenic (As) is a carcinogenic metalloid that enters food chain through food and water and poses health risk to living beings. It is important to assess the As status in the environment and risks associated with it. Hence, a risk assessment study was conducted across Ropar wetland, Punjab, India and its environs in pre-monsoon season of 2013, to estimate the risk posed to adults and children via daily consumption of As contaminated groundwater and wheat grains. Arsenic concentrations determined in groundwater, soil and wheat grain samples using atomic absorption spectrometer ranged from 2.90 to 10.56 μg L(-1), 0.06 to 0.12 mg kg(-1) and 0.03 to 0.21 mg kg(-1), respectively. Arsenic in wheat grains showed significant negative correlation with phosphate content in soil indicating a competitive uptake of arsenate and phosphate ions by plants. Principal component analysis and cluster analysis suggested that both natural and anthropogenic factors contribute to variation in As content and other variables studied in soil and groundwater samples. Total cancer risk and hazard index were higher than the USEPA safety limits of 1.00 × 10(-6) and 1, respectively, for both adults and children indicating a high risk of cancer and other health disorders. Consumption of As contaminated wheat grains was found to pose higher risk of cancer and non-cancer health disorders as compared to intake of As contaminated groundwater by both adults and children. Moreover, children were found to be more prone to cancer and other heath disorders due to As exposure via wheat grains and groundwater as compared to adults.

  9. Arsenic in groundwater in the North Carolina Eastern slate belt (Esb): Nash and halifax counties, north carolina

    Science.gov (United States)

    Reid, J.C.; Haven, W.T.; Eudy, D.D.; Milosh, R.M.; Stafford, E.G.

    2010-01-01

    Naturally occurring arsenic-contaminated groundwater is present within the Eastern Slate Belt (ESB) of North Carolina. Long-term, integrated geologic and geo-chemical investigations havedetermined the presence of arsenic by analyzing precipitates from first and second order streams under base flow conditions. When groundwater discharges into streams, arsenic and other metals are precipitated from solution, due to redox changes between the subsurface and surface environments. Analyses (As, base metals, Fe and Mn) were determined following chemical extraction ofnaturally occurring manganese-iron oxide-coatings, which had precipitated from solution onto stream-bed cobbles. Additionally, artificial redox fronts were produced by placing ceramic tilesin streambeds to collect and analyze oxide precipitates. Thermochemical plots from these data, as well as information from respective stream water measurements (pH and Eh), water sampling, and rock chemical analyses indicate mobile arsenic in predicted stability fields. Initial results show that naturally occurring arsenic-contaminated groundwater is present within the study area. However, the resulting oxidation and pre-cipitation within streams appreciably removes thiscontaminant from surface water solution.

  10. Arsenic removal from contaminated groundwater by membrane-integrated hybrid plant: optimization and control using Visual Basic platform.

    Science.gov (United States)

    Chakrabortty, S; Sen, M; Pal, P

    2014-03-01

    A simulation software (ARRPA) has been developed in Microsoft Visual Basic platform for optimization and control of a novel membrane-integrated arsenic separation plant in the backdrop of absence of such software. The user-friendly, menu-driven software is based on a dynamic linearized mathematical model, developed for the hybrid treatment scheme. The model captures the chemical kinetics in the pre-treating chemical reactor and the separation and transport phenomena involved in nanofiltration. The software has been validated through extensive experimental investigations. The agreement between the outputs from computer simulation program and the experimental findings are excellent and consistent under varying operating conditions reflecting high degree of accuracy and reliability of the software. High values of the overall correlation coefficient (R (2) = 0.989) and Willmott d-index (0.989) are indicators of the capability of the software in analyzing performance of the plant. The software permits pre-analysis, manipulation of input data, helps in optimization and exhibits performance of an integrated plant visually on a graphical platform. Performance analysis of the whole system as well as the individual units is possible using the tool. The software first of its kind in its domain and in the well-known Microsoft Excel environment is likely to be very useful in successful design, optimization and operation of an advanced hybrid treatment plant for removal of arsenic from contaminated groundwater.

  11. Groundwater pollution by arsenic and its effect on health. Present state of groundwater pollution by arsenic and its environmental quality standard; Hiso ni yoru chikasui osen to kenko eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Nakajima, N.

    1997-07-10

    Resorted the official data of groundwater inspections in Japan for fiscal 1995 in accordance with the new environmental quality standard (revised in 1997), the largest number of samples that exceeded the standard values among 23 inspection items of substances was of arsenic (As: standard 0.01mg/l). In this case, 49 samples out of total 2720 samples exceeded the standard values due to As (excess ratio 1.8%). The next substances having high excess ratio were four organic chlorine compounds which are widely used as detergent (excess ratio 0.6-0.1%), and next to these was lead (0.1%). About the other substances, excess was not found. The birthplaces of the above 48 samples were as follows: Fukuoka prefecture (12 samples), Chiba (19), Saitama (7), Gunma (4), Miyagi (4), Niigata (3), Hokkaido (2), Yamagata (1, the followings were also the same), Tokyo, Aichi, Osaka, Hyogo, Tottori. Recently, arsenic poisoning in Bangladesh has been reported, and the cause of it is estimated as excessive pumping up of irrigation water. In Japan, future strengthening of surveillance is expected. 2 figs., 5 tabs.

  12. 地下水砷污染研究进展%Research Progress of Arsenic Contamination in Groundwater

    Institute of Scientific and Technical Information of China (English)

    金阳; 姜月华; 李云

    2015-01-01

    Arsenic is a severely toxic substance resulting in cancer. Arsenic contamination of groundwater has had a sig-nificantly negative influence not only on human health, but also on ecological environment, and it has been a hot issue for a-broad and domestic scholars in recent years. This paper summarizes arsenic contamination in groundwater, introduces current status of the research focused on Arsenic in groundwater, meanwhile, it also simply depicts its source. In addition, this article shows several aspects of Arsenic contamination in details, including existence form, impact factors, and points out the instruc-tion for preventive control and remediation of arsenic contamination in groundwater.%砷是一种毒性很强的致癌物质,地下水的砷污染严重破坏生态环境,危害人类健康,已成为近年来国内外学者研究的热点问题。本文针对地下水的砷污染问题进行综述,介绍了地下水砷污染研究现状,并简单介绍了地下水中砷的来源。另外,还针对地下水中砷的存在形态及其影响因素等方面作了详细介绍,对砷污染的预防控制和修复治理起到指导作用。

  13. Adsorption/Oxidation of arsenic in groundwater by nanoscale Fe-Mn binary oxides loaded on zeolite.

    Science.gov (United States)

    Kong, Shuqiong; Wang, Yanxin; Zhan, Hongbin; Yuan, Songhu; Yu, Mei; Liu, Mingliang

    2014-02-01

    Nanoscale Fe-Mn binary oxides loaded on zeolite (NIMZ) is synthesized and characterized. The as-synthesized adsorbent is amorphous with 126 m2/g surface area; it is effective for the adsorption of both As(III) and As(V) in synthetic groundwater. It has high adsorption capacities of 296.23 and 201.10 mg/g for As(III) and As(V), respectively. For the adsorption of 2 mg/L arsenic, the aqueous concentration quickly decreases to less than 10 /microg/L within 30 min. During the adsorption of As(III), the in-aqueous measurement of As(V) shows a low concentration in the initial stage and disappears afterward. The fraction of As(V) on NIMZ gradually increases with time, proving the oxidation of As(III). The adsorption of As(III) and As(V) decreases with increasing pH. The anions of SiO3(2-), H2PO4(-), and HCO3(-) significantly compete with arsenic for the adsorption sites. The innersphere surface complexes are formed by As(III) or As(V) with the hydroxyl groups on the surface of NIMZ.

  14. Arsenic contamination of groundwater and its induced health effects in Shahpur block, Bhojpur district, Bihar state, India: risk evaluation.

    Science.gov (United States)

    Chakraborti, Dipankar; Rahman, Mohammad Mahmudur; Ahamed, Sad; Dutta, Rathindra Nath; Pati, Shyamapada; Mukherjee, Subhash Chandra

    2016-05-01

    The objective of this study was to determine the magnitude of groundwater arsenic contamination in Shahpur block of Bhojpur district, Bihar state, India and its health effects such as dermal, neurological, obstetric effects, and cancer risk. The School of Environmental Studies (SOES) collected 4704 tube-well water samples from all 88 villages of Shahpur, which were analyzed for arsenic. We found 40.3 and 21.1 % of the tube-wells had arsenic above 10 and 50 μg/l, respectively, with maximum concentration of 1805 μg/l. The study shows that 75,000, 39,000, and 10,000 people could be exposed to arsenic-contaminated water greater than 10, 50, and 300 μg/l, respectively. Our medical team examined 1422 villagers from Shahpur and registered 161 (prevalence rate, 11.3 %) with arsenical skin lesions. Arsenical skin lesions were also observed in 29 children of 525 screened. We analyzed 579 biological samples (hair, nail, and urine) from Shahpur and found that 82, 89, and 91 % of hair, nail, and urine, respectively, had arsenic above the normal levels, indicating many people in the study area are sub-clinically affected. Arsenical neuropathy was observed in 48 % of 102 arsenicosis patients. The study also found that arsenic exposed women with severe skin lesions had adversely affected their pregnancies. The carcinogenic and non-carcinogenic risks were also estimated based on the generated data. Safe drinking water supply is urgently required to combat arsenic situation in affected villages of Shahpur.

  15. Arsenic pollution sources.

    Science.gov (United States)

    Garelick, Hemda; Jones, Huw; Dybowska, Agnieszka; Valsami-Jones, Eugenia

    2008-01-01

    Arsenic is a widely dispersed element in the Earth's crust and exists at an average concentration of approximately 5 mg/kg. There are many possible routes of human exposure to arsenic from both natural and anthropogenic sources. Arsenic occurs as a constituent in more than 200 minerals, although it primarily exists as arsenopyrite and as a constituent in several other sulfide minerals. The introduction of arsenic into drinking water can occur as a result of its natural geological presence in local bedrock. Arsenic-containing bedrock formations of this sort are known in Bangladesh, West Bengal (India), and regions of China, and many cases of endemic contamination by arsenic with serious consequences to human health are known from these areas. Significant natural contamination of surface waters and soil can arise when arsenic-rich geothermal fluids come into contact with surface waters. When humans are implicated in causing or exacerbating arsenic pollution, the cause can almost always be traced to mining or mining-related activities. Arsenic exists in many oxidation states, with arsenic (III) and (V) being the most common forms. Similar to many metalloids, the prevalence of particular species of arsenic depends greatly on the pH and redox conditions of the matrix in which it exists. Speciation is also important in determining the toxicity of arsenic. Arsenic minerals exist in the environment principally as sulfides, oxides, and phosphates. In igneous rocks, only those of volcanic origin are implicated in high aqueous arsenic concentrations. Sedimentary rocks tend not to bear high arsenic loads, and common matrices such as sands and sandstones contain lower concentrations owing to the dominance of quartz and feldspars. Groundwater contamination by arsenic arises from sources of arsenopyrite, base metal sulfides, realgar and orpiment, arsenic-rich pyrite, and iron oxyhydroxide. Mechanisms by which arsenic is released from minerals are varied and are accounted for by

  16. Improved removal of arsenic from groundwater using pre-corroded steel and iron tailored granular activated carbon.

    Science.gov (United States)

    Zou, J; Cannon, F S; Chen, W; Dempsey, B A

    2010-01-01

    The authors have combined corrosion of steel fittings or perforated sheets with granular activated carbon (GAC) that had been pre-treated with Fe(III)-citrate, to produce an innovative and low-maintenance technique for removing arsenic from groundwater. Removal of arsenic was measured using two GAC column configurations: rapid small scale column tests (RSSCT's) and mini-column tests. Independent variables included pH, pre-corrosion procedure, and idling of the column (i.e. intentionally stopping flow for defined times in order to create reducing conditions). Use of corroded steel plus pre-treated GAC removed arsenic to below 10 microg/L for up to 248,000 bed volumes (BV) at pH 6, compared to 7,000 BVs for pre-treated GAC without pre-corroded steel. Performance was not as good at pH 6.5 or 7.5. Idling the system recovered the iron corrosion ability by reducing the passive Fe(III) layer on pre-corroded steel surface, as a result the BVs to arsenic breakthrough was doubled. But idling also caused brief periods of arsenic and iron release after restart, due to reductive dissolution of arsenic-containing ferric oxides. GAC was also effective as filtration media for removal of iron (hydr)oxide particles (and associated arsenic) that was released from the pre-corroded iron.

  17. Co-contamination of arsenic and fluoride in the groundwater of unconsolidated aquifers under reducing environments.

    Science.gov (United States)

    Kim, Seok-Hwi; Kim, Kangjoo; Ko, Kyung-Seok; Kim, Yeongkyoo; Lee, Kwang-Sik

    2012-05-01

    The co-contamination of arsenic (As) and fluoride (F(-)) in shallow aquifers is frequently observed worldwide, and the correlations between those contaminants are different according to the redox conditions. This study geochemically explores the reasons for the co-contamination and for the redox-dependent correlations by investigating the groundwater of an alluvial aquifer in Korea. Geochemical signatures of the groundwater in the study area show that the As concentrations are enriched by the reductive dissolution of Fe-(hydr)oxides, and the correlations between As and F(-) concentrations are poor comparatively to those observed in the oxidizing aquifers. However, F(-) concentrations are strongly dependent on pH. Desorption/adsorption experiments using raw soils and citrate-bicarbonate-dithionite treated soils indicated that Fe-(hydr)oxides are the important As and F(-) hosts causing the co-contamination phenomenon. The weaker correlation between F(-) and As in reducing aquifers is likely to be associated with sulfate reduction, which removes As from groundwater without changing the F(-) concentration. Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. Origin of high ammonium, arsenic and boron concentrations in the proximity of a mine: Natural vs. anthropogenic processes

    Energy Technology Data Exchange (ETDEWEB)

    Scheiber, Laura, E-mail: scheiber.ls@gmail.com [Institute of Environmental Assessment and Water Research, CSIC, Jordi Girona 18. E-08034 Barcelona (Spain); Ayora, Carlos; Vázquez-Suñé, Enric [Institute of Environmental Assessment and Water Research, CSIC, Jordi Girona 18. E-08034 Barcelona (Spain); Cendón, Dioni I. [Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232 (Australia); School of Biological, Earth and Environmental Sciences (BEES), University of New South Wales (UNSW), NSW 2052 (Australia); Soler, Albert [Departament de Cristallografia, Mineralogia i Dipòsits Minerals, Facultat de Geologia, Universitat de Barcelona, C/Martí Franquès, sn., Barcelona (Spain); Baquero, Juan Carlos [Cobre Las Cruces S.A., Carretera SE-3410 km 4, 41860 Gerena, Sevilla (Spain)

    2016-01-15

    High ammonium (NH{sub 4}), arsenic (As) and boron (B) concentrations are found in aquifers worldwide and are often related to human activities. However, natural processes can also lead to groundwater quality problems. High NH{sub 4}, As and B concentrations have been identified in the confined, deep portion of the Niebla-Posadas aquifer, which is near the Cobre Las Cruces (CLC) mining complex. The mine has implemented a Drainage and Reinjection System comprising two rings of wells around the open pit mine, were the internal ring drains and the external ring is used for water reinjection into the aquifer. Differentiating geogenic and anthropogenic sources and processes is therefore crucial to ensuring good management of groundwater in this sensitive area where groundwater is extensively used for agriculture, industry, mining and human supply. No NH{sub 4}, As and B are found in the recharge area, but their concentrations increase with depth, salinity and residence time of water in the aquifer. The increased salinity down-flow is interpreted as the result of natural mixing between infiltrated meteoric water and the remains of connate waters (up to 8%) trapped within the pores. Ammonium and boron are interpreted as the result of marine solid organic matter degradation by the sulfate dissolved in the recharge water. The light δ{sup 15}N{sub NH4} values confirm that its origin is linked to marine organic matter. High arsenic concentrations in groundwater are interpreted as being derived from reductive dissolution of As-bearing goethite by dissolved organic matter. The lack of correlation between dissolved Fe and As is explained by the massive precipitation of siderite, which is abundantly found in the mineralization. Therefore, the presence of high arsenic, ammonium and boron concentrations is attributed to natural processes. Ammonium, arsenic, boron and salinity define three zones of groundwater quality: the first zone is close to the recharge area and contains water

  19. 家庭饮用地下水的除砷装置实验研究%Experimental Study on Arsenic Removal Purification Device of Family Drinking Groundwater

    Institute of Scientific and Technical Information of China (English)

    张西珠; 赵彤璐

    2014-01-01

    According to the causes of endemic arsenic poisoning disease and the distribution of high-arsenic drinking water areas in Shanxi province ,an arsenic removal purification device of family drinking groundwater using new composite materials for removing arsenic was presented ,aiming at the situation that no low-arsenic shallow water ,deep groundwater ,spring water and river water can be drawn in those areas .Based on the pr-esented device ,the parameter was optimized and the structure was designed .Then the statistical data ob-tained from the experiment of removing arsenic from high-arsenic drinking water and the life expectancy test of the device was were analyzed .The experimental results illustrate that intermittent filtration is much better than continuous filtration .This device is proved to be of longer service life expectancy and with better filtering effect in practice .The problem of drinking water in endemic area can be effectively solved .%根据山西省地方性砷中毒病的形成原因和山西省饮用高砷水地区的分布情况,针对该地区内无低砷浅层水、深层地下水、泉水、河水可引的情况,提出了一种利用新型复合除砷材料的家庭饮用地下水的除砷净化装置,并对所提装置进行了参数优化和结构设计,分析了病区高含砷量饮用水处理试验以及装置寿命试验的统计数据。研究结果表明,间歇过滤比连续过滤除砷效果好,装置使用寿命更长,过滤效果更好,能有效地解决病区居民的饮用水问题。

  20. On mobilization of lead and arsenic in groundwater in response to CO2 leakage from deep geological storage

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, L.; Apps, J.A.; Zhang, Y.; Xu, T.; Birkholzer, J.T.

    2009-07-01

    If carbon dioxide stored in deep saline aquifers were to leak into an overlying aquifer containing potable groundwater, the intruding CO{sub 2} would change the geochemical conditions and cause secondary effects mainly induced by changes in pH In particular, hazardous trace elements such as lead and arsenic, which are present in the aquifer host rock, could be mobilized. In an effort to evaluate the potential risks to potable water quality, reactive transport simulations were conducted to evaluate to what extent and mechanisms through which lead and arsenic might be mobilized by intrusion of CO{sub 2}. An earlier geochemical evaluation of more than 38,000 groundwater quality analyses from aquifers throughout the United States and an associated literature review provided the basis for setting up a reactive transport model and examining its sensitivity to model variation. The evaluation included identification of potential mineral hosts containing hazardous trace elements, characterization of the modal bulk mineralogy for an arenaceous aquifer, and augmentation of the required thermodynamic data. The reactive transport simulations suggest that CO{sub 2} ingress into a shallow aquifer can mobilize significant lead and arsenic, contaminating the groundwater near the location of intrusion and further downstream. Although substantial increases in aqueous concentrations are predicted compared to the background values, the maximum permitted concentration for arsenic in drinking water was exceeded in only a few cases, whereas that for lead was never exceeded.

  1. Preliminary study on the mode of occurrence of arsenic in high arsenic coals from southwest Guizhou Province

    Institute of Scientific and Technical Information of China (English)

    丁振华; 郑宝山; 张杰; H.; E.; Belkin; R.; B.; Finkelman; 赵峰华; 周代兴; 周运书; 陈朝刚

    1999-01-01

    Coal samples from high arsenic coal areas have been analyzed by electron microprobe analyzer ( EMPA) , scanning electron microscopy with an energy dispersive X-ray analyzer (SEM-EDX) , X-ray diffraction analysis (XRD) , low temperature ashing (LTA) , transmission electron microscopy (TEM) , X-ray absorption fine structure (XAFS) , instrument neutron activation analysis (INAA) and wet chemical analysis. Although some As-bearing minerals such as pyrite, arsenopyrite, realgar (?), As-bearing sulfate, and As-bearing clays are found in the high arsenic coals, their contents do not account for the abundance of arsenic in the some coals. Analysis of the coal indicates that arsenic exists mainly in the form of As5+ and As3+ , combined with compounds in the organic matrix. The occurrence of such exceptionally high arsenic contents in coal and the fact that the arsenic is dominantly organically associated are unique observations. The modes of occurrence of arsenic in high As-coals are discussed.

  2. Arsenic and fluoride removal from groundwater by electrocoagulation using a continuous filter-press reactor.

    Science.gov (United States)

    Guzmán, Athziri; Nava, José L; Coreño, Oscar; Rodríguez, Israel; Gutiérrez, Silvia

    2016-02-01

    We investigated simultaneous arsenic and fluoride removal from ground water by electrocoagulation (EC) using aluminum as the sacrificial anode in a continuous filter-press reactor. The groundwater was collected at a depth of 320 m in the Bajío region in Guanajuato Mexico (arsenic 43 µg L(-1), fluoride 2.5 mg L(-1), sulfate 89.6 mg L(-1), phosphate 1.8 mg L(-1), hydrated silica 112.4 mg L(-1), hardness 9.8 mg L(-1), alkalinity 31.3 mg L(-1), pH 7.6 and conductivity 993 µS cm(-1)). EC was performed after arsenite was oxidized to arsenate by addition of 1 mg L(-1) hypochlorite. The EC tests revealed that at current densities of 4, 5 and 6 mA cm(-2) and flow velocities of 0.91 and 1.82 cm s(-1), arsenate was abated and residual fluoride concentration satisfies the WHO standard (CF < 1.5 mg L(-1)). Spectrometric analyses performed on aluminum flocs indicated that these are mainly composed of aluminum-silicates of calcium and magnesium. Arsenate removal by EC involves adsorption on aluminum flocs, while fluoride replaces a hydroxyl group from aluminum aggregates. The best EC was obtained at 4 mA cm(-2) and 1.82 cm s(-1) with electrolytic energy consumption of 0.34 KWh m(-3).

  3. A novel low-cost detection method for screening of arsenic in groundwater.

    Science.gov (United States)

    Fontàs, Clàudia; Vera, Ruben; Batalla, Anna; Kolev, Spas D; Anticó, Enriqueta

    2014-10-01

    In the present work, a novel and simple detection system for As inorganic species contained in groundwater is presented. To reach the required detection limit, the proposed methodology is based on two steps: first is the transport and preconcentration of the inorganic arsenic species using a polymer inclusion membrane (PIM) system and second is the formation of a coloured complex, the absorbance of which is measured. Different parameters related to the membrane composition and the transport kinetics have been studied, and it was found that membranes made of polyvinyl chloride (PVC) as a polymer, and Aliquat 336 as a carrier, ensured efficient arsenic transport when the carrier content was at least 31 % (w/w). The implementation of the designed PIM in a special device that contained only 5 mL of the stripping solution (0.1 M NaCl) allowed As preconcentration from a 100-mL water sample, thus facilitating its detection with the colorimetric method. The new method developed here was validated, and its analytical figures of merit were determined, i.e. limit of detection of 4.5 μg L(-1) at 820 nm and a relative standard deviation within the range 8-10 %. Finally, the method was successfully applied to the analysis of different water samples from Catalonia region with naturally occurring As.

  4. Hydrogeochemistry of co-occurring geogenic arsenic, fluoride and iodine in groundwater at Datong Basin, northern China

    Energy Technology Data Exchange (ETDEWEB)

    Pi, Kunfu; Wang, Yanxin, E-mail: yx.wang@cug.edu.cn; Xie, Xianjun, E-mail: xjxie@cug.edu.cn; Su, Chunli; Ma, Teng; Li, Junxia; Liu, Yaqing

    2015-12-30

    Highlights: • Co-mobilization of As, F and I was identified at Datong Basin. • Both As and I are released via reductive dissolution of Fe minerals. • Some amounts of As and I may be sequestered by FeS precipitates. • Intensive evaporation promotes retention of As but mobilization of F and I. - Abstract: Abnormal levels of co-occurring arsenic (As), fluorine (F) and iodine (I) in groundwater at Datong Basin, northern China are geochemically unique. Hydrochemical, {sup 18}O and {sup 2}H characteristics of groundwater were analyzed to elucidate their mobilization processes. Aqueous As, F and I ranged from 5.6 to 2680 μg/L, 0.40 to 3.32 mg/L and 10.1 to 186 μg/L, respectively. High As, F and I groundwater was characterized by moderately alkaline, high HCO{sub 3}{sup −}, Fe(II), HS{sup −} and DOC concentrations with H{sub 3}AsO{sub 3}, F{sup −} and I{sup −} as the dominant species. The plots of δ{sup 18}O values and Cl/Br ratios versus Cl{sup −} concentration demonstrate build-up of more oxidizing conditions and precipitation of carbonate minerals induced by vertical recharge and intensive evaporation facilitate As retention to Fe (hydr) oxides, but enhance F and I mobilization from host minerals. Under reducing conditions, As and I can be simultaneously released via reductive dissolution of Fe (hydr) oxides and reduction of As(V) and I(V) while F migration may be retarded due to effects of dissolution-precipitation equilibria between carbonate minerals and fluorite. With the prevalence of sulfate-reducing condition and lowering of HCO{sub 3}{sup −} concentration, As and I may be sequestered by Fe(II) sulfides and F is retained to fluorite and on clay mineral surfaces.

  5. Summary of four scientific studies on Arsenicum album high dilution effect against Arsenic intoxication in mice

    Directory of Open Access Journals (Sweden)

    Laurence Terzan

    2012-09-01

    Full Text Available Background: Groundwater arsenic affects millions of people in about 20 countries. In West Bengal (India and Bangladesh alone over 100 million people are exposed. The arsenic concentration in contaminated groundwater in Bangladesh was above the maximum permissible level of 0.05 mg/l as recommended by WHO for developing countries [1]. Drinking water is not the only source of poisoning. In arsenic contaminated areas, crops, vegetables, cereals, poultry, cattle, etc, also contain traces of arsenic. Chronic arsenic intoxication has been associated with several diseases such as melanosis, leuco-melanosis, hyperkeratosis, oedema, skin cancer… Cazin et al [2], have demonstrated the effect of high dilutions of arsenic compounds. They noted increased arsenic elimination from blood through urine and faeces in intoxicated rats. According to these research, the aim of Khuda Buksh studies [3-4-5] was to investigate whether high dilution Arsenicum album have any effect on arsenic accumulation in different tissues and to understand also how this high dilution could produce a protective effect on all the different organs. Methodology: Firstly, the effect of Arsenicum album 30 cH on the amount of arsenic accumulation was determined by spectrophotometric analysis in four tissues namely liver, kidney and testis in mice intoxicated by arsenic. The protective effect in chronic and acute arsenic intoxicated mice of Arsenicum Album 6cH, 30cH and 200cH has been evaluated using not only the activities of enzymatic and biomarker toxicity (aspartate amino transferase (AST, alanine amino transferase (ALT, acid phosphatase (AcP, alkaline phosphatase (AlkP, lipid peroxidation (LPO and reduced glutathione (GSH but also the cytogenetical parameters (chromosome aberrations (CA, mitotic index (MI, sperm head anomaly (SHA etc., . Because, it is well demonstrated that these enzymes biomarkers reflect the degree of hepatotoxicity and oxidative stress caused by

  6. Groundwater-soil-crop relationship with respect to arsenic contamination in farming villages of Bangladesh - A preliminary study

    Energy Technology Data Exchange (ETDEWEB)

    Kurosawa, Kiyoshi [Institute of Tropical Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi -Ku, Fukuoka 812 8581 (Japan)], E-mail: kurosawa@agr.kyushu-u.ac.jp; Egashira, Kazuhiko [Faculty of Agriculture, Kyushu University, Fukuoka 812 8581 (Japan); Tani, Masakazu [Faculty of Design, Kyushu University, Fukuoka 815 8540 (Japan); Jahiruddin, M.; Moslehuddin, Abu Zofar Md. [Department of Soil Science, Bangladesh Agricultural University, Mymensingh 2202 (Bangladesh); Rahman, Zulfikar Md. [Department of Agricultural Extension Education, Bangladesh Agricultural University, Mymensingh 2202 (Bangladesh)

    2008-11-15

    To clarify the groundwater-soil-crop relationship with respect to arsenic (As) contamination, As concentration was measured in tubewell (TW) water, surface soil from farmyards and paddy fields, and fresh taro (Colocasia esculenta) leaves from farmyards in the farming villages of Bangladesh. The As concentration in TW water from farmyards was at least four times higher than the Bangladesh drinking water standard, and the concentration in fresh taro leaves was equal to or higher than those reported previously for leafy vegetables in Bangladesh. As concentration of surface soils in both farmyards and paddy fields was positively correlated with that of the TW water. Further, the concentration in surface soil was positively correlated with levels in fresh taro leaves in the farmyard. This study, therefore, clarified the groundwater-soil-crop relationship in farmyards and the relationship between groundwater-soil in paddy fields to assess the extent of As contamination in Bangladeshi villages. - By extracting arsenic contaminated groundwater from a well, surface soil surrounding the well and crops planted in the surface soil became contaminated with arsenic.

  7. Arsenic

    Science.gov (United States)

    ... WHO Language عربي 中文 English Français Русский Español Media centre Menu Media centre News News releases Previous ... this water and eating food irrigated with arsenic-rich water, can lead to chronic arsenic poisoning. Skin ...

  8. Arsenic in groundwaters of rural India: its geochemistry and mitigation approaches

    Science.gov (United States)

    Chatterjee, Debashis; Majumder, Santanu; Kundu, Amit; Barman, Sandipan; Chatterjee, Debankur; Bhattacharya, Prosun

    2016-04-01

    During the last few decades, arsenic (As) has been recognized as the most threatening contaminant in natural waters (especially groundwater). It has become a menace to the health of millions of people worldwide. Many large and small communities experience As contamination in groundwater and/or drinking water supplies in south-east Asia and the problem is grave in West Bengal and Bangladesh (Bengal Delta Plain, BDP) both in terms of human exposure as well as spatial coverage. It is frequently observed that As concentration in contaminated wells exceeds both WHO guideline value (10 mg/l) and stipulated National standard (50 mg/l) for both Bangladesh and India. Dissolved forms of As in the BDP water include arsenite (~50-70%), arsenate (~30-50%) and ultra-trace amount of monomethylarsonic acid and dimethylarsinic acid. Arsenite and arsenate species can interchange depending on redox potential (Eh), pH and biological processes. The prevailing local geomorphological features (surface water, sanitation, agricultural activity) can also influence the mobilization of As in addition to the dominant geological factors. Therefore, the local sedimentology and hydrogeology should also be given importance prior to implement or consider any policy to mitigate the As contamination of groundwater. Conventional treatment techniques to remove As from groundwater are costly and difficult to practice in rural areas of the BDP. There are several techniques available for groundwater As removal. Iron and Alum coagulation, softening [mediated by calcite or Mg(OH)2 formation], by reverse osmosis, using zero-valent iron and nanoparticulate zero-valent iron, several natural/synthetic metal oxides, naturally found minerals like siderite, hematite, using iron doped activated carbons, development of bio-physicochemical techniques, using granular TiO2 adsorbent are some of the many proposed removal techniques investigated by various researchers. Instead of using hazardous chemicals (e.g. chlorine

  9. Correlation of Breastmilk Arsenic With Maternal, Infant Urinary Arsenic and Drinking Water Arsenic in an Arsenic Affected Area of Bangladesh

    Science.gov (United States)

    Alauddin, M.; Islam, M. R.; Milton, A. H.; Alauddin, S. T.; Mouly, T.; Behri, E.; Ayesha, A.; Akter, S.; Islam, M. M.

    2016-12-01

    About 97% of population in Bangladesh depend on groundwater as the principle source of drinking water and this water is highly contaminated with inorganic arsenic. Consumption of arsenic contaminated drinking water by pregnant women raises the prospect of early life exposure to inorganic arsenic for newborn which may be lead to adverse health effect in later life. This work was carried out in parts of Gopalganj district in Bangladesh, a region affected by arsenic contamination in groundwater. The objective of the work was to assess potential early life exposure to arsenic for infants through breastfeeding by mothers who were drinking water with arsenic levels ranging from 100 to 300 µg/l. A cohort of 30 mother-baby pairs were selected for the current study. Breastmilk samples from mothers, urine samples from each pair of subjects at 1, 6 and 9 month age of infant were collected and total arsenic were determined in these samples. In addition speciation of urinary arsenic and metabolites were carried out in 12 mother-baby pairs. Median level for breastmilk arsenic were 0.50 µg/l. Urinary arsenic of infants did not correlate with breastmilk arsenic with progressing age of infants. Maternal and infant urinary total arsenic at 1 month age of infant showed some positive correlation (r = 0.39). In infant urine major metabolite were dimethyl arsenic acid (DMA) (approximately 70%) indicating good methylating capacity for infants at 1 and 6 months of age. In conclusion, infants were not exposed to arsenic through breastfeeding even though mothers were exposed to significant levels of arsenic through drinking water.

  10. Flow and sorption controls of groundwater arsenic in individual boreholes from bedrock aquifers in central Maine, USA.

    Science.gov (United States)

    Yang, Qiang; Culbertson, Charles W; Nielsen, Martha G; Schalk, Charles W; Johnson, Carole D; Marvinney, Robert G; Stute, Martin; Zheng, Yan

    2015-02-01

    To understand the hydrogeochemical processes regulating well water arsenic (As) evolution in fractured bedrock aquifers, three domestic wells with [As] up to 478 μg/L are investigated in central Maine. Geophysical logging reveals that fractures near the borehole bottom contribute 70-100% of flow. Borehole and fracture water samples from various depths show significant proportions of As (up to 69%) and Fe (93-99%) in particulates (>0.45 μm). These particulates and those settled after a 16-day batch experiment contain 560-13,000 mg/kg of As and 14-35% weight/weight of Fe. As/Fe ratios (2.5-20 mmol/mol) and As partitioning ratios (adsorbed/dissolved [As], 20,000-100,000 L/kg) suggest that As is sorbed onto amorphous hydrous ferric oxides. Newly drilled cores also show enrichment of As (up to 1300 mg/kg) sorbed onto secondary iron minerals on the fracture surfaces. Pumping at high flow rates induces large decreases in particulate As and Fe, a moderate increase in dissolved [As] and As(III)/As ratio, while little change in major ion chemistry. The δD and δ(18)O are similar for the borehole and fracture waters, suggesting a same source of recharge from atmospheric precipitation. Results support a conceptual model invoking flow and sorption controls on groundwater [As] in fractured bedrock aquifers whereby oxygen infiltration promotes the oxidation of As-bearing sulfides at shallower depths in the oxic portion of the flow path releasing As and Fe; followed by Fe oxidation to form Fe oxyhydroxide particulates, which are transported in fractures and sorb As along the flow path until intercepted by boreholes. In the anoxic portions of the flow path, reductive dissolution of As-sorbed iron particulates could re-mobilize As. For exposure assessment, we recommend sampling of groundwater without filtration to obtain total As concentration in groundwater.

  11. Flow and sorption controls of groundwater arsenic in individual boreholes from bedrock aquifers in central Maine, USA

    Science.gov (United States)

    Yang, Qiang; Culbertson, Charles W.; Nielsen, Martha G.; Schalk, Charles W.; Johnson, Carole D.; Marvinney, Robert G.; Stute, Martin; Zheng, Yan

    2014-01-01

    To understand the hydrogeochemical processes regulating well water arsenic (As) evolution in fractured bedrock aquifers, three domestic wells with [As] up to 478 μg/L are investigated in central Maine. Geophysical logging reveals that fractures near the borehole bottom contribute 70-100% of flow. Borehole and fracture water samples from various depths show significant proportions of As (up to 69%) and Fe (93-99%) in particulates (>0.45 μm). These particulates and those settled after a 16-day batch experiment contain 560-13,000 g/kg of As and 14-35% weight/weight of Fe. As/Fe ratios (2.5-20 mmol/mol) and As partitioning ratios (adsorbed/dissolved [As], 20,000-100,000 L/kg) suggest that As is sorbed onto amorphous hydrous ferric oxides. Newly drilled cores also show enrichment of As (up to 1300 mg/kg) sorbed onto secondary iron minerals on the fracture surfaces. Pumping at high flow rates induces large decreases in particulate As and Fe, a moderate increase in dissolved [As] and As(III)/As ratio, while little change in major ion chemistry. The δD and δ18O are similar for the borehole and fracture waters, suggesting a same source of recharge from atmospheric precipitation. Results support a conceptual model invoking flow and sorption controls on groundwater [As] in fractured bedrock aquifers whereby oxygen infiltration promotes the oxidation of As-bearing sulfides at shallower depths in the oxic portion of the flow path releasing As and Fe; followed by Fe oxidation to form Fe oxyhydroxide particulates, which are transported in fractures and sorb As along the flow path until intercepted by boreholes. In the anoxic portions of the flow path, reductive dissolution of As-sorbed iron particulates could re-mobilize As. For exposure assessment, we recommend sampling of groundwater without filtration to obtain total As concentration in groundwater.

  12. Flow and sorption controls of groundwater arsenic in individual boreholes from bedrock aquifers in central Maine, USA

    Science.gov (United States)

    Yang, Qiang; Culbertson, Charles W.; Nielsen, Martha G.; Schalk, Charles W.; Johnson, Carole D.; Marvinney, Robert G.; Stute, Martin; Zheng, Yan

    2014-01-01

    To understand the hydrogeochemical processes regulating well water arsenic (As) evolution in fractured bedrock aquifers, three domestic wells with [As] up to 478 µg/L are investigated in central Maine. Geophysical logging reveals that fractures near the borehole bottom contribute 70–100% of flow. Borehole and fracture water samples from various depths show significant proportions of As (up to 69%) and Fe (93–99%) in particulates (>0.45 µm). These particulates and those settled after a 16-day batch experiment contain 560–13,000 mg/kg of As and 14–35% weight/weight of Fe. As/Fe ratios (2.5–20 mmole/mole) and As partitioning ratios (adsorbed/dissolved [As], 20,000–100,000 L/kg) suggest that As is sorbed onto amorphous hydrous ferric oxides. Newly drilled cores also show enrichment of As (up to 1,300 mg/kg) sorbed onto secondary iron minerals on the fracture surfaces. Pumping at high flow rates induces large decreases in particulate As and Fe, a moderate increase in dissolved [As] and As(III)/As ratio, while little change in major ion chemistry. The δD and δ18O are similar for the borehole and fracture waters, suggesting a same source of recharge from atmospheric precipitation. Results support a conceptual model invoking flow and sorption controls on groundwater [As] in fractured bedrock aquifers whereby oxygen infiltration promotes oxidation of As-bearing sulfides at shallower depths in the oxic portion of the flow path releasing As and Fe; followed by Fe oxidation to form Fe oxyhydroxide particulates, which are transported in fractures and sorb As along the flow path until intercepted by boreholes. In the anoxic portions of the flow path, reductive dissolution of As-sorbed iron particulates could re-mobilize As. For exposure assessment, we recommend sampling of groundwater without filtration to obtain total As concentration in groundwater. PMID:24842411

  13. Sediment biomarker, bacterial community characterization of high arsenic aquifers in Jianghan Plain, China

    Science.gov (United States)

    Ye, Hengpeng; Yang, Zeyu; Wu, Xiang; Wang, Jingwen; Du, Dongyun; Cai, Jian; Lv, Kangle; Chen, Huiyun; Mei, Jingkun; Chen, Mengqi; Du, Hong

    2017-01-01

    Representative biomarkers (e.g., n-alkanes), diversity and microbial community in the aquifers contaminated by high concentration of arsenic (As) in different sediment depth (0–30 m) in Jianghan Plain, Hubei, China, were analyzed to investigate the potential mechanism of As enrichment in groundwater. The concentration of As was abundant in top soil and sand, but not in clay. The analysis of the distribution of n-alkanes, CPI values, and wax to total n-alkane ratio (Wax(n)%) indicated that the organic matter (OM) from fresh terrestrial plants were abundant in the shallow sediment. However, n-alkanes have suffered from significant biodegradation from the depth of 16 m to 30 m. The deposition of fresh terrestrial derived organic matters may facilitate the release of As from sediment to groundwater in the sediment of 0–16 m. However, the petroleum derived organic matters may do the favor to the release of As in the deeper section of borehole (16 m to 30 m). The 16S rRNA gene sequences identification indicated that Acidobacteria, Actinomycetes and Hydrogenophaga are abundant in the sediments with high arsenic. Therefore, microbes and organic matters from different sources may play important roles in arsenic mobilization in the aquifers of the study area. PMID:28165031

  14. Hydrological and geochemical constraints on the mechanism of formation of arsenic contaminated groundwater in Sonargaon, Bangladesh

    Energy Technology Data Exchange (ETDEWEB)

    Itai, Takaaki [Institute for Study of the Earth' s Interior, Okayama University, Misasa, Tottori 682-0193 (Japan)], E-mail: itai-epss@hiroshima-u.ac.jp; Masuda, Harue [Department of Geosciences, Osaka-City University, Sugimoto-tyo, Sumiyoshi, Osaka 558-8585 (Japan); Seddique, Ashraf A. [Department of Geosciences, Osaka-City University, Sugimoto-tyo, Sumiyoshi, Osaka 558-8585 (Japan); Department of Geology, University of Dhaka, Dhaka 1000 (Bangladesh); Mitamura, Muneki [Department of Geosciences, Osaka-City University, Sugimoto-tyo, Sumiyoshi, Osaka 558-8585 (Japan); Maruoka, Teruyuki [Department of Integrative Environmental Science, University of Tsukuba, Tsukuba, Ibaraki 305-8572 (Japan); Li, Xiaodong [Department of Geosciences, Osaka-City University, Sugimoto-tyo, Sumiyoshi, Osaka 558-8585 (Japan); Kusakabe, Minoru [Institute for Study of the Earth' s Interior, Okayama University, Misasa, Tottori 682-0193 (Japan); Dipak, Biswas K. [Department of Geology, University of Dhaka, Dhaka 1000 (Bangladesh); Farooqi, Abida [Department of Geosciences, Osaka-City University, Sugimoto-tyo, Sumiyoshi, Osaka 558-8585 (Japan); Yamanaka, Toshiro [Department of Earth Systems Science, Okayama University, 3-1-1 Tsushima-naka Okayama 700-8530 (Japan); Nakaya, Shinji [Department of Civil Engineering, Shinshu University, Wakazato, Nagano 380-8553 (Japan); Matsuda, Jun-ichi [Department of Earth and Space Science, Osaka University, 1-1 Machikaneyama-tyo, Toyonaka-shi, Osaka 560-0043 (Japan); Ahmed, Kazi Matin [Department of Geology, University of Dhaka, Dhaka 1000 (Bangladesh)

    2008-11-15

    The geochemical characteristics and hydrological constraints of high As groundwater in Sonargaon, in mid-eastern Bangladesh were investigated in order to ascertain the mechanism of As release into the groundwaters from host sediments in the Ganges-Brahmaputra delta. Samples of groundwater were collected from ca. 230 tube wells in both the rainy and dry seasons. Similar to previous studies, high As groundwater was found in the Holocene unconfined aquifer but not in the Pleistocene aquifer. Groundwaters in the Holocene aquifer were of the Ca-Mg-HCO{sub 3} type with major solutes derived from chemical weathering of detrital minerals such as plagioclase and biotite. Groundwater with high As was generally characterized by high NH{sub 4}{sup +}, possibly derived from the agricultural application of fertilizer as suggested by the small variation of {delta}{sup 15}N{sub NH4} (mostly 2-4 per mille ). Concentrations of Fe changed between the rainy and dry seasons by precipitation/dissolution of Fe oxyhydroxide and siderite, whilst there was not an apparent concomitant change in As. Inhomogeneous spatial distribution of {delta}{sup 18}O in the Holocene unconfined aquifer indicates poor mixing of groundwater in the horizontal direction. Spatial variation of redox conditions is associated with localized variations in subsurface permeability and the recharge/discharge cycle of groundwater. Hydrogeochemical data presented in this paper suggest that reduction of Fe oxyhydroxide is not the only mechanism of As mobilization, and chemical weathering of biotite and/or other basic minerals in the Holocene aquifer could also be important as a primary cause of As mobilization.

  15. Origin of high ammonium, arsenic and boron concentrations in the proximity of a mine: Natural vs. anthropogenic processes.

    Science.gov (United States)

    Scheiber, Laura; Ayora, Carlos; Vázquez-Suñé, Enric; Cendón, Dioni I; Soler, Albert; Baquero, Juan Carlos

    2016-01-15

    High ammonium (NH4), arsenic (As) and boron (B) concentrations are found in aquifers worldwide and are often related to human activities. However, natural processes can also lead to groundwater quality problems. High NH4, As and B concentrations have been identified in the confined, deep portion of the Niebla-Posadas aquifer, which is near the Cobre Las Cruces (CLC) mining complex. The mine has implemented a Drainage and Reinjection System comprising two rings of wells around the open pit mine, were the internal ring drains and the external ring is used for water reinjection into the aquifer. Differentiating geogenic and anthropogenic sources and processes is therefore crucial to ensuring good management of groundwater in this sensitive area where groundwater is extensively used for agriculture, industry, mining and human supply. No NH4, As and B are found in the recharge area, but their concentrations increase with depth, salinity and residence time of water in the aquifer. The increased salinity down-flow is interpreted as the result of natural mixing between infiltrated meteoric water and the remains of connate waters (up to 8%) trapped within the pores. Ammonium and boron are interpreted as the result of marine solid organic matter degradation by the sulfate dissolved in the recharge water. The light δ(15)NNH4 values confirm that its origin is linked to marine organic matter. High arsenic concentrations in groundwater are interpreted as being derived from reductive dissolution of As-bearing goethite by dissolved organic matter. The lack of correlation between dissolved Fe and As is explained by the massive precipitation of siderite, which is abundantly found in the mineralization. Therefore, the presence of high arsenic, ammonium and boron concentrations is attributed to natural processes. Ammonium, arsenic, boron and salinity define three zones of groundwater quality: the first zone is close to the recharge area and contains water of sufficient quality for

  16. Arsenic methylation and skin lesions in migrant and native adult women with chronic exposure to arsenic from drinking groundwater.

    Science.gov (United States)

    Wei, Binggan; Yu, Jiangping; Yang, Linsheng; Li, Hairong; Chai, Yuanqing; Xia, Yajuan; Wu, Kegong; Gao, Jianwei; Guo, Zhiwei; Cui, Na

    2017-02-01

    In order to figure out the prevalence of skin lesions and methylation capacity for migrant and native adult women in an endemic area for arsenic poisoning in Inner Mongolia, China, 207 adult women were selected for study subjects. The results showed that the prevalence of skin lesions for the external group, provincial group and native group was 36.54, 26.15 and 35.56 %, respectively. The nail content of arsenic and urinary concentrations of dimethylarsenic (DMA), monomethylarsenic (MMA) and inorganic arsenic (iAs) were significantly higher in women with skin lesions than in those without skin lesions. The highest urinary concentrations of DMA, MMA and iAs were 213.93, 45.72 and 45.01 μg/L in the native group. The arsenic methylation capacity index revealed that the external group had the greatest capacity, while the native group had the lowest. The odds ratios of skin lesions in relation to arsenic metabolites and arsenic methylation capacity varied widely among the three groups. Urinary MMA and iAs concentrations were positively associated with risk of skin lesions in the three groups of adult women, while primary and secondary methylation capacities were negatively related to risk of skin lesions in native and provincial groups. The external group might be more susceptible to MMA and iAs, while the provincial and native groups were more tolerance to MMA and iAs. Lower primary and secondary arsenic methylation capacities increased the risk of skin lesions in native and provincial groups. Moreover, higher nail arsenic concentration increased the risk of skin lesions of adult women.

  17. A decade of investigations on groundwater arsenic contamination in Middle Ganga Plain, India.

    Science.gov (United States)

    Saha, Dipankar; Sahu, Sudarsan

    2016-04-01

    Groundwater arsenic (As) load in excess of drinking limit (50 µg L(-1)) in the Gangetic Plains was first detected in 2002. Though the menace was known since about two decades from the downstream part of the plains in the Bengal Basin, comprising of Lower Ganga Plain and deltaic plains of Ganga-Brahmaputra-Meghna River system, little thought was given to its possible threat in the upstream parts in the Gangetic Plains beyond Garo-Rajmahal Hills. The contamination in Bengal Basin has become one of the extensively studied issues in the world and regarded as the severest case of health hazard in the history of mankind. The researches and investigations in the Gangetic Plains during the last decade (2003-2013) revealed that the eastern half of the plains, also referred as Middle Ganga Plain (MGP), is particularly affected by contamination, jeopardising the shallow aquifer-based drinking water supply. The present paper reviews researches and investigations carried out so far in MGP by various research institutes and government departments on wide array of issues of groundwater As such as its spatio-temporal variation, mobilisation paths, water level behaviour and flow regime, configuration of contaminated and safe aquifers and their recharge mechanism. Elevated conc. of groundwater As has been observed in grey and dark grey sediments of Holocene age (Newer Alluvium) deposited in a fluvio-lacustrine environment in the floodplain of the Ganga and most of its northern tributaries from Himalayas. Older Alluvium, comprising Pleistocene brownish yellow sediment, extending as deeper aquifers in Newer Alluvium areas, is low in groundwater As. Similarities and differences on issues between the MGP and the Bengal Basin have been discussed. The researches point towards the mobilisation process as reductive dissolution of iron hydroxide coating, rich in adsorbed As, mediated by microbial processes. The area is marked with shallow water level (<8.0 m below ground) with ample

  18. Surface-enhanced raman spectroscopy substrate for arsenic sensing in groundwater

    Science.gov (United States)

    Yang, Peidong; Mulvihill, Martin; Tao, Andrea R.; Sinsermsuksakul, Prasert; Arnold, John

    2015-06-16

    A surface-enhanced Raman spectroscopy (SERS) substrate formed from a plurality of monolayers of polyhedral silver nanocrystals, wherein at least one of the monolayers has polyvinypyrrolidone (PVP) on its surface, and thereby configured for sensing arsenic is described. Highly active SERS substrates are formed by assembling high density monolayers of differently shaped silver nanocrystals onto a solid support. SERS detection is performed directly on this substrate by placing a droplet of the analyte solution onto the nanocrystal monolayer. Adsorbed polymer, polyvinypyrrolidone (PVP), on the surface of the nanoparticles facilitates the binding of both arsenate and arsenite near the silver surface, allowing for highly accurate and sensitive detection capabilities.

  19. Ranking traditional and nano-enabled sorbents for simultaneous removal of arsenic and chromium from simulated groundwater.

    Science.gov (United States)

    Gifford, Mac; Hristovski, Kiril; Westerhoff, Paul

    2017-12-01

    Water from many municipal and private wells are treated to meet arsenic (As(V)) regulations, and new regulations for hexavalent chromium (Cr(VI)) are soon possible. Rather than adding costly capital infrastructure, we explored many types of sorbents' ability to remove both oxygenated anions simultaneously. In laboratory pseudo-equilibrium tests, metal (hydr)oxide sorbents demonstrated high affinity for As(V) but exhibited 30 to 100-fold lower capacities to remove Cr(VI). WBAX resins had some ability to sorb both Cr(VI) and As(V), but competing anions lowered their sorption capacity for As(V) by >90% compared to in a deionized water matrix. Nano-enabled sorbents with iron or titanium nanoparticles embedded inside the porous structure of an anion exchange resin demonstrated high ability to remove both pollutants simultaneously despite competition, with the tested sorbents showing 11μmol/g capacity for Cr(VI) and 19μmol/g for As(V) in simulated groundwater on average. To quantitatively rank sorbents' ability to remove multiple pollutants, a Simultaneous Removal Capacity scoring tool is proposed. This index uses both absolute removal capacity for each contaminant and relative capacity for multiple contaminants, and may be applied to simultaneous removal of any set of aqueous or atmospheric contaminants. Here, the five nano-enabled sorbents ranked in the top seven out of twelve sorbents tested for simultaneous Cr(VI) and As(V) removal. This work demonstrated traditional and novel nano-enabled sorbents can reduce multiple contaminants of health concern, resulting in groundwater treated to drinking water standards. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Arsenic and other trace elements in groundwater and human urine in Ha Nam province, the Northern Vietnam: contamination characteristics and risk assessment.

    Science.gov (United States)

    Pham, Long Hai; Nguyen, Hue Thi; Van Tran, Cuong; Nguyen, Ha Manh; Nguyen, Tung Hoang; Tu, Minh Binh

    2017-06-01

    The contamination characteristics of arsenic and other trace elements in groundwater and the potential risks of arsenic from the groundwater were investigated. Elevated contamination of arsenic, barium and manganese was observed in tube-well water of two villages (Chuyen Ngoai and Chau Giang) in Ha Nam province in the Northern Vietnam. Concentrations of As in the groundwater ranged from 12.8 to 884 µg/L with mean values in Chuyen Ngoai and Chau Giang were 614.7 and 160.1 µg/L, respectively. About 83 % of these samples contained As concentrations exceeding WHO drinking water guideline of 10 μg/L. The mean values of Mn and Ba in groundwater from Chuyen Ngoai and Chau Giang were 300 and 657 μg/L and 650 and 468 μg/L, respectively. The mean value of Ba concentration in groundwater in both Chuyen Ngoai and Chau Giang was about 22 % of the samples exceeded the WHO guideline (700 µg/L). Arsenic concentrations in human urine of residents from Chuyen Ngoai and Chau Giang were the range from 8.6 to 458 µg/L. The mean values of Mn and Ba in human urine of local people from Chuyen Ngoai were 46.9 and 62.8 μg/L, respectively, while those in people from Chau Giang were 25.9 and 45.9 μg/L, respectively. The average daily dose from ingesting arsenic for consuming both untreated and treated groundwater is from 0.02 to 11.5 and 0.003 to 1.6 μg/kg day, respectively. Approximately, 57 % of the families using treated groundwater and 64 % of the families using untreated groundwater could be affected by elevated arsenic exposure.

  1. Bayesian modeling approach for characterizing groundwater arsenic contamination in the Mekong River basin.

    Science.gov (United States)

    Cha, YoonKyung; Kim, Young Mo; Choi, Jae-Woo; Sthiannopkao, Suthipong; Cho, Kyung Hwa

    2016-01-01

    In the Mekong River basin, groundwater from tube-wells is a major drinking water source. However, arsenic (As) contamination in groundwater resources has become a critical issue in the watershed. In this study, As species such as total As (AsTOT), As(III), and As(V), were monitored across the watershed to investigate their characteristics and inter-relationships with water quality parameters, including pH and redox potential (Eh). The data illustrated a dramatic change in the relationship between AsTOT and Eh over a specific Eh range, suggesting the importance of Eh in predicting AsTOT. Thus, a Bayesian change-point model was developed to predict AsTOT concentrations based on Eh and pH, to determine changes in the AsTOT-Eh relationship. The model captured the Eh change-point (∼-100±15mV), which was compatible with the data. Importantly, the inclusion of this change-point in the model resulted in improved model fit and prediction accuracy; AsTOT concentrations were strongly negatively related to Eh values higher than the change-point. The process underlying this relationship was subsequently posited to be the reductive dissolution of mineral oxides and As release. Overall, AsTOT showed a weak positive relationship with Eh at a lower range, similar to those commonly observed in the Mekong River basin delta. It is expected that these results would serve as a guide for establishing public health strategies in the Mekong River Basin. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Geochemical tracing of As pollution in the Orbiel Valley (southern France): 87Sr/86Sr as a tracer of the anthropogenic arsenic in surface and groundwater.

    Science.gov (United States)

    Khaska, Mahmoud; Le Gal La Salle, Corinnne; Lancelot, Joël; Verdoux, Patrick; Boutin, René

    2014-05-01

    The environmental impacts of arsenic mining activities and their effects on ecosystem and human health are observed in many stream waters and groundwater. The aim of this study is to identify the origin of As content in a mining environment using Sr isotopes. At the Salsigne gold mine, before the closure in 2004, high arsenic content has been observed in surface water and groundwater in the Orbiel valley. At the site, immobilization of As, in As rich leachate, is carried out by adding CaO. High contrast in 87Sr/86Sr between Arsenic rich minerals associated with Variscan metamorphic rocks (0.714888-0.718835), together with rich As waste water (0.713463-715477), and the CaO (0.707593) allows as to trace the origin of anthropogenic As. In 2012, Orbiel stream waters were sampled monthly upstream and downstream from the ancient ore processing site and once after an important rainy event (117mm). The upstream valley samples showed low and relatively constant As content with natural regional background of 3.6 and 5.6 μg/L. The rainy event induced only a slight increase in the As content up to 6.3 μg/L. High 87Sr/86Sr ratios suggested an influence of radiogenic Sr issued from the Variscan metamorphic basement. Downstream from the area, the As content was at least10 time as high. In the wet season, stream water As content clearly increased to 13.9-24 μg/L, reaching 120.5 μg/L during the rainy event. Associated 87Sr/86Sr ratio showed to be less radiogenic (0.712276-0.714002). The anti correlation observed between As and 87Sr/86Sr suggest that As issued from a natural origin is characterised by a high 87Sr/86Sr compared to As derived from the CaO treatement used on site and characterized by a low 87Sr/86Sr ratio. During the dry season, increase in As content was observed reaching 110 μg/L. These highlights the contribution of alluvial groundwater to base flow, probably associated with As reach leachate from the site. Contribution from the alluvial aquifer is confirmed by

  3. The distribution of arsenic in shallow alluvial groundwater under agricultural land in central Portugal: insights from multivariate geostatistical modeling.

    Science.gov (United States)

    Andrade, A I A S S; Stigter, T Y

    2013-04-01

    In this study multivariate and geostatistical methods are jointly applied to model the spatial and temporal distribution of arsenic (As) concentrations in shallow groundwater as a function of physicochemical, hydrogeological and land use parameters, as well as to assess the related uncertainty. The study site is located in the Mondego River alluvial body in Central Portugal, where maize, rice and some vegetable crops dominate. In a first analysis scatter plots are used, followed by the application of principal component analysis to two different data matrices, of 112 and 200 samples, with the aim of detecting associations between As levels and other quantitative parameters. In the following phase explanatory models of As are created through factorial regression based on correspondence analysis, integrating both quantitative and qualitative parameters. Finally, these are combined with indicator-geostatistical techniques to create maps indicating the predicted probability of As concentrations in groundwater exceeding the current global drinking water guideline of 10 μg/l. These maps further allow assessing the uncertainty and representativeness of the monitoring network. A clear effect of the redox state on the presence of As is observed, and together with significant correlations with dissolved oxygen, nitrate, sulfate, iron, manganese and alkalinity, points towards the reductive dissolution of Fe (hydr)oxides as the essential mechanism of As release. The association of high As values with rice crop, known to promote reduced environments due to ponding, further corroborates this hypothesis. An additional source of As from fertilizers cannot be excluded, as the correlation with As is higher where rice is associated with vegetables, normally associated with higher fertilization rates. The best explanatory model of As occurrence integrates the parameters season, crop type, well and water depth, nitrate and Eh, though a model without the last two parameters also gives

  4. Single and combined effects of phosphate, silicate, and natural organic matter on arsenic removal from soft and hard groundwater using ferric chloride

    Science.gov (United States)

    Chanpiwat, Penradee; Hanh, Hoang Thi; Bang, Sunbaek; Kim, Kyoung-Woong

    2017-01-01

    In order to assess the effects of phosphate, silicate and natural organic matter (NOM) on arsenic removal by ferric chloride, batch coprecipitation experiments were conducted over a wide pH range using synthetic hard and soft groundwaters, similar to those found in northern Vietnam. The efficiency of arsenic removal from synthetic groundwater by coprecipitation with FeCl3 was remarkably decreased by the effects of PO4 3-, SiO4 4- and NOM. The negative effects of SiO4 4- and NOM on arsenic removal were not as strong as that of PO4 3-. Combining PO4 3- and SiO4 4- increased the negative effects on both arsenite (As3+) and arsenate (As5+) removal. The introduction of NOM into the synthetic groundwater containing both PO4 3- and SiO4 4- markedly magnified the negative effects on arsenic removal. In contrast, both Ca2+ and Mg2+ substantially increased the removal of As3+ at pH 8-12 and the removal of As5+ over the entire pH range. In the presence of Ca2+ and Mg2+, the interaction of NOM with Fe was either removed or the arsenic binding to Fe-NOM colloidal associations and/or dissolved complexes were flocculated. Removal of arsenic using coprecipitation by FeCl3 could not sufficiently reduce arsenic contents in the groundwater (350 μg/L) to meet the WHO guideline for drinking water (10 μg/L), especially when the arsenic-rich groundwater also contains co-occurring solutes such as PO4 3-, SiO4 4- and NOM; therefore, other remediation processes, such as membrane technology, should be introduced or additionally applied after this coprecipitation process, to ensure the safety of drinking water.

  5. Single and combined effects of phosphate, silicate, and natural organic matter on arsenic removal from soft and hard groundwater using ferric chloride

    Science.gov (United States)

    Chanpiwat, Penradee; Hanh, Hoang Thi; Bang, Sunbaek; Kim, Kyoung-Woong

    2017-06-01

    In order to assess the effects of phosphate, silicate and natural organic matter (NOM) on arsenic removal by ferric chloride, batch coprecipitation experiments were conducted over a wide pH range using synthetic hard and soft groundwaters, similar to those found in northern Vietnam. The efficiency of arsenic removal from synthetic groundwater by coprecipitation with FeCl3 was remarkably decreased by the effects of PO4 3-, SiO4 4- and NOM. The negative effects of SiO4 4- and NOM on arsenic removal were not as strong as that of PO4 3-. Combining PO4 3- and SiO4 4- increased the negative effects on both arsenite (As3+) and arsenate (As5+) removal. The introduction of NOM into the synthetic groundwater containing both PO4 3- and SiO4 4- markedly magnified the negative effects on arsenic removal. In contrast, both Ca2+ and Mg2+ substantially increased the removal of As3+ at pH 8-12 and the removal of As5+ over the entire pH range. In the presence of Ca2+ and Mg2+, the interaction of NOM with Fe was either removed or the arsenic binding to Fe-NOM colloidal associations and/or dissolved complexes were flocculated. Removal of arsenic using coprecipitation by FeCl3 could not sufficiently reduce arsenic contents in the groundwater (350 μg/L) to meet the WHO guideline for drinking water (10 μg/L), especially when the arsenic-rich groundwater also contains co-occurring solutes such as PO4 3-, SiO4 4- and NOM; therefore, other remediation processes, such as membrane technology, should be introduced or additionally applied after this coprecipitation process, to ensure the safety of drinking water.

  6. Arsenic removal from groundwater of the Chaco-Pampean plain (Argentina) using natural geological materials as adsorbents.

    Science.gov (United States)

    Bundschuh, Jochen; Bhattacharya, Prosun; Sracek, Ondra; Mellano, M Fernanda; Ramírez, Antonio E; Storniolo, Angel del R; Martín, Raúl A; Cortés, Julia; Litter, Marta I; Jean, Jiin-Shuh

    2011-01-01

    Use of natural geological materials for arsenic (As) removal is an emerging solution at a household level for poor people in remote rural settlements, especially when the materials are locally available and can be collected by the local population. Their low or zero cost makes these materials very attractive compared with synthetic or commercial materials. Sometimes, this may be the only option to provide safe water to very poor settlements. Their suitability for As removal from water is mainly due to adsorption, co-precipitation and ion exchange processes involving Fe- and Al-rich minerals and clay minerals present in the soils or sediments. In the present study, various clay-rich soils from the Santiago del Estero province (SDE, NW Argentina) and, for comparison, a laterite from the Misiones province have been tested as adsorbents for As in shallow naturally contaminated groundwaters of the Río Dulce alluvial aquifer in SDE. Batch adsorption experiments showed higher As(V) removal for the Misiones laterite sample (99 %) as compared with the soils from SDE (40-53 %), which can be related to lower contents of water-soluble and oxalate extractable Al and Fe in the last samples. These results suggest the application of the Misiones laterite soil as an alternative for As removal. However, high transportation costs from Misiones to SDE can be an economical restriction for the low-income population of SDE.

  7. Analytical Investigation of Arsenic and Iron in hand pump and tube-well groundwater of Gambat, Sindh, Pakistan

    Directory of Open Access Journals (Sweden)

    *M. A. Jakhrani

    2011-09-01

    Full Text Available Contamination of drinking water especially with heavy metals is now a major issue from both the public health and the environmental health perspectives. In present work we are reporting a multivariate study for the concentrations of Arsenic and Iron in groundwater n=334 collected from Gambat, Khairpur, Sindh, Pakistan during year 2008. The analysis was performed using Hydride Generator Atomic Absorption Spectrometry (HG-ASS Perkin Elmer A-100 coupled with MHS-15. Arsenic and Iron were evaluated in hand pump and tube well water sample with detection limit 0.02µgL-1and 01µgL-1 respectively. The level of arsenic was found in hand pump and tube well water ranged from <0.01 to 126µgL-1 and <0.01-38 µgl-1 respectively. While level of Iron was found in the rage of <0.004-1.6mgL-1 and <0.004-1.5mgL-1 in hand pump and tube well groundwater respectively. It has observed that in most of the samples level of these both elements were above than the maximum permissible level of World Health Organization.

  8. Influence of geology on groundwater-sediment interactions in arsenic enriched tectono-morphic aquifers of the Himalayan Brahmaputra river basin

    Science.gov (United States)

    Verma, Swati; Mukherjee, Abhijit; Mahanta, Chandan; Choudhury, Runti; Mitra, Kaushik

    2016-09-01

    those being major constituents in a gabbroic complex (ophiolite) and basalt terrain in S-region. The aquifers of S-region are severely contaminated with dissolved As compared to NW and N regions. Almost more than 92% of groundwater samples in the southern part (maximum 5.53 μM or 415 μg/L) are enriched with As, which draws a distinct difference from the NW and N parts of BRB aquifers. The redox-sensitive solutes (i.e., Fe, Mn, HCO3- and TOC) are positively correlated with As in NW and N-parts; whereas EH shows negative to very weak positive correlation which suggests that a redox-dependent mobilization plays important role in As liberation in NW and N parts of the basin. However, As in southern aquifers is not showing any correlation or weak negative correlation with redox-sensitive solutes; suggesting that multiple reactions and hydrogeochemical processes and their interaction control As mobilization and fate in the S-region of BRB. The occurrence of high concentrations of arsenic in groundwater of Brahmaputra basin is described through a crustal recycling model and tectonic movement between the Indian-Eurasian plates and Burmese micro-continents. As-enriched groundwater in Himalayan foreland basin in the BRB is probably a result of crustal evolution through which As is subsequently mobilized from aquifer matrix to solution in groundwater by water-sediment reaction under favorable biogeochemical conditions. The results of the study indicate geological control (i.e. change in lithofacies, tectonic set-up) on groundwater chemistry and distribution of redox-sensitive solutes such as As.

  9. Characterization of Organic Carbon and Its Bioavailability in Recharge Waters and Aquifer Sediments: Implications for Groundwater Arsenic Contamination in Bangladesh

    Science.gov (United States)

    Pracht, L. E.; Ardissono, R. J.; Polizzotto, M.; Badruzzaman, A. B. M.; Ali, M. A.; Paša-Tolić, L.; Neumann, R. B.

    2014-12-01

    Arsenic contamination of groundwater in Bangladesh affects millions of people, as groundwater is the primary source of both drinking and irrigation water in the country. The arsenic is of geologic origin, naturally-occurring in the aquifer sediment. However, the source of organic carbon that fuels the microbial reactions responsible for mobilizing arsenic off the sediment and into the groundwater has been debated for over a decade. The outstanding question is whether this organic carbon is sedimentary carbon that was co-deposited when the aquifers were formed, or surface-derived organic carbon transported into the subsurface along with recharge water. The answer to this question has implications for managing the contamination problem. Here we present results of recent laboratory incubations of aquifer sediment with recharge waters collected from our field site in Bangladesh. The incubations revealed a hitherto undocumented pool of biodegradable sedimentary organic carbon. Despite the carbon being old (thousands of years), it was rapidly utilized by the native microbial population. The results imply that within the aquifer this pool of sedimentary organic carbon is largely unavailable to the microbial community, but that chemical and/or physical perturbations to the subsurface, induced, for example, by large-scale groundwater pumping or microbial activity, could mobilize this bioavailable organic carbon off the sediment. Currently, we are using Fourier Transform Ion Cyclotron Resonance Mass Spectrometry and spectroscopic techniques to understand the initial character of the mobilized organic carbon in our incubation experiments, and to track how its composition changes over time as it is degraded by microbes. These efforts will help clarify the in situ processes that could destabilize the sedimentary organic carbon and identify the components that make the carbon biologically available. Collectively, our data suggest a possible role for both surface-derived and

  10. Flow and sorption controls of groundwater arsenic in individual boreholes from bedrock aquifers in central Maine, USA

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Qiang [Lamont-Doherty Earth Observatory of Columbia University, 61 Route 9 W, Palisades, NY 10964 (United States); School of Earth and Environmental Sciences, Queens College and Graduate Center, City University of New York, 65-30 Kissena Blvd., Flushing, NY 11367 (United States); Culbertson, Charles W.; Nielsen, Martha G.; Schalk, Charles W. [U.S. Geological Survey, Maine Water Science Center, 196 Whitten Road, Augusta, ME 04330 (United States); Johnson, Carole D. [U.S. Geological Survey, Branch of Geophysics, 11 Sherman Place, Unit 5015, University of Connecticut, Storrs, CT 06269 (United States); Marvinney, Robert G. [Maine Geological Survey, 93 State House Station, Augusta, ME 04333 (United States); Stute, Martin [Lamont-Doherty Earth Observatory of Columbia University, 61 Route 9 W, Palisades, NY 10964 (United States); Zheng, Yan, E-mail: yan.zheng@qc.cuny.edu [Lamont-Doherty Earth Observatory of Columbia University, 61 Route 9 W, Palisades, NY 10964 (United States); School of Earth and Environmental Sciences, Queens College and Graduate Center, City University of New York, 65-30 Kissena Blvd., Flushing, NY 11367 (United States)

    2015-02-01

    To understand the hydrogeochemical processes regulating well water arsenic (As) evolution in fractured bedrock aquifers, three domestic wells with [As] up to 478 μg/L are investigated in central Maine. Geophysical logging reveals that fractures near the borehole bottom contribute 70–100% of flow. Borehole and fracture water samples from various depths show significant proportions of As (up to 69%) and Fe (93–99%) in particulates (> 0.45 μm). These particulates and those settled after a 16-day batch experiment contain 560–13,000 mg/kg of As and 14–35% weight/weight of Fe. As/Fe ratios (2.5–20 mmol/mol) and As partitioning ratios (adsorbed/dissolved [As], 20,000–100,000 L/kg) suggest that As is sorbed onto amorphous hydrous ferric oxides. Newly drilled cores also show enrichment of As (up to 1300 mg/kg) sorbed onto secondary iron minerals on the fracture surfaces. Pumping at high flow rates induces large decreases in particulate As and Fe, a moderate increase in dissolved [As] and As(III)/As ratio, while little change in major ion chemistry. The δD and δ{sup 18}O are similar for the borehole and fracture waters, suggesting a same source of recharge from atmospheric precipitation. Results support a conceptual model invoking flow and sorption controls on groundwater [As] in fractured bedrock aquifers whereby oxygen infiltration promotes the oxidation of As-bearing sulfides at shallower depths in the oxic portion of the flow path releasing As and Fe; followed by Fe oxidation to form Fe oxyhydroxide particulates, which are transported in fractures and sorb As along the flow path until intercepted by boreholes. In the anoxic portions of the flow path, reductive dissolution of As-sorbed iron particulates could re-mobilize As. For exposure assessment, we recommend sampling of groundwater without filtration to obtain total As concentration in groundwater. - Highlights: • Most Fe and some As exist as particulates in the tested borehole and fracture water.

  11. Synthesis and Characterization of Hybrid-Magnetic Nanoparticles and Their Application for Removal of Arsenic from Groundwater

    Directory of Open Access Journals (Sweden)

    Marta A. Bavio

    2013-01-01

    Full Text Available Multiwall carbon nanotubes (MWCNTs were oxidized with different agents and a characterization study was carried out. Then, hybrid-magnetic nanoparticles (HMNPs were synthesized as iron oxide supported on the selected multiwalled carbon nanotubes (MWCNTs-Fe3O4 obtained from MWCNTs oxidized with HNO3. The HMNPs characterization revealed the presence of iron oxide as magnetite onto the MWCNTs surfaces. These HMNPs were used for arsenic removal from groundwater. The adsorption process variables were optimized (concentration of NPs, contact time, and pH, and these systems could remove 39.93 mg As/g adsorbent. Therefore, these nanoparticles appear as a good alternative for removing arsenic from water samples.

  12. Groundwater Arsenic Contamination in the Bengal Delta Plain of Bangladesh : KTH Special Publication. Proceedings of the KTH-Dhaka University Seminar

    OpenAIRE

    2001-01-01

    The Bengal Delta Plain, like many deltas in Asia, is densely populated. Natural conditions are favourable in terms of soil fertility and abundance of water resources for cultivation. Groundwater is abundant and easily accessible by wells. However, the well drilling campaigns during the last few decades, intended to supply safe water to nearly 97% the population, have turned out to bring out water with toxic levels of arsenic over large areas of the country. The mechanisms of the arsenic mobil...

  13. The influence of groundwater chemistry on arsenic concentrations and speciation in a quartz sand and gravel aquifera

    Directory of Open Access Journals (Sweden)

    Fox Patricia M

    2004-04-01

    Full Text Available We examined the chemical reactions influencing dissolved concentrations, speciation, and transport of naturally occurring arsenic (As in a shallow, sand and gravel aquifer with distinct geochemical zones resulting from land disposal of dilute sewage effluent. The principal geochemical zones were: (1 the uncontaminated zone above the sewage plume [350 μM dissolved oxygen (DO, pH 5.9]; (2 the suboxic zone (5 μM DO, pH 6.2, elevated concentrations of sewage-derived phosphate and nitrate; and (3 the anoxic zone [dissolved iron(II 100–300 μM, pH 6.5–6.9, elevated concentrations of sewage-derived phosphate]. Sediments are comprised of greater than 90% quartz but the surfaces of quartz and other mineral grains are coated with nanometer-size iron (Fe and aluminum (Al oxides and/or silicates, which control the adsorption properties of the sediments. Uncontaminated groundwater with added phosphate (620 μM was pumped into the uncontaminated zone while samples were collected 0.3 m above the injection point. Concentrations of As(V increased from below detection (0.005 μM to a maximum of 0.07 μM during breakthrough of phosphate at the sampling port; As(III concentrations remained below detection. These results are consistent with the hypothesis that naturally occurring As(V adsorbed to constituents of the coatings on grain surfaces was desorbed by phosphate in the injected groundwater. Also consistent with this hypothesis, vertical profiles of groundwater chemistry measured prior to the tracer test showed that dissolved As(V concentrations increased along with dissolved phosphate from below detection in the uncontaminated zone to approximately 0.07 and 70 μM, respectively, in the suboxic zone. Concentrations of As(III were below detection in both zones. The anoxic zone had approximately 0.07 μM As(V but also had As(III concentrations of 0.07–0.14 μM, suggesting that release of As bound to sediment grains occurred by desorption by phosphate

  14. The influence of groundwater chemistry on arsenic concentrations and speciation in a quartz sand and gravel aquifer

    Science.gov (United States)

    Kent, D.B.; Fox, P.M.

    2004-01-01

    We examined the chemical reactions influencing dissolved concentrations, speciation, and transport of naturally occurring arsenic (As) in a shallow, sand and gravel aquifer with distinct geochemical zones resulting from land disposal of dilute sewage effluent. The principal geochemical zones were: (1) the uncontaminated zone above the sewage plume [350 ??M dissolved oxygen (DO), pH 5.9]; (2) the suboxic zone (5 ??M DO, pH 6.2, elevated concentrations of sewage-derived phosphate and nitrate); and (3) the anoxic zone [dissolved iron(II) 100-300 ??M, pH 6.5-6.9, elevated concentrations of sewage-derived phosphate]. Sediments are comprised of greater than 90% quartz but the surfaces of quartz and other mineral grains are coated with nanometer-size iron (Fe) and aluminum (Al) oxides and/or silicates, which control the adsorption properties of the sediments. Uncontaminated groundwater with added phosphate (620 ??M) was pumped into the uncontaminated zone while samples were collected 0.3 m above the injection point. Concentrations of As(V) increased from below detection (0.005 ??M) to a maximum of 0.07 ??M during breakthrough of phosphate at the sampling port; As(III) concentrations remained below detection. These results are consistent with the hypothesis that naturally occurring As(V) adsorbed to constituents of the coatings on grain surfaces was desorbed by phosphate in the injected groundwater. Also consistent with this hypothesis, vertical profiles of groundwater chemistry measured prior to the tracer test showed that dissolved As(V) concentrations increased along with dissolved phosphate from below detection in the uncontaminated zone to approximately 0.07 and 70 ??M, respectively, in the suboxic zone. Concentrations of As(III) were below detection in both zones. The anoxic zone had approximately 0.07 ??M As(V) but also had As(III) concentrations of 0.07-0.14 ??M, suggesting that release of As bound to sediment grains occurred by desorption by phosphate, reductive

  15. A survey of arsenic, manganese, boron, thorium, and other toxic metals in the groundwater of a West Bengal, India neighbourhood.

    Science.gov (United States)

    Bacquart, Thomas; Bradshaw, Kelly; Frisbie, Seth; Mitchell, Erika; Springston, George; Defelice, Jeffrey; Dustin, Hannah; Sarkar, Bibudhendra

    2012-07-01

    Around 150 million people are at risk from arsenic-contaminated groundwater in India and Bangladesh. Multiple metal analysis in Bangladesh has found other toxic elements above the World Health Organization (WHO) health-based drinking water guidelines which significantly increases the number of people at risk due to drinking groundwater. In this study, drinking water samples from the Bongaon area (North 24 Parganas district, West Bengal, India) were analyzed for multiple metal contamination in order to evaluate groundwater quality on the neighbourhood scale. Each sample was analyzed for arsenic (As), boron (B), barium (Ba), chromium (Cr), manganese (Mn), molybdenum (Mo), nickel (Ni), lead (Pb), and uranium (U). Arsenic was found above the WHO health-based drinking water guideline in 50% of these tubewells. Mn and B were found at significant concentrations in 19% and 6% of these tubewells, respectively. The maps of As, Mn, and B concentrations suggest that approximately 75% of this area has no safe tubewells. The concentrations of As, Mn, B, and many other toxic elements are independent of each other. The concentrations of Pb and U were not found above WHO health-based drinking water guidelines but they were statistically related to each other (p-value = 0.001). An analysis of selected isotopes in the Uranium, Actinium, and Thorium Radioactive Decay Series revealed the presence of thorium (Th) in 31% of these tubewells. This discovery of Th, which does not have a WHO health-based drinking water guideline, is a potential public health challenge. In sum, the widespread presence and independent distribution of other metals besides As must be taken into consideration for drinking water remediation strategies involving well switching or home-scale water treatment.

  16. Distribution of arsenic concentrations in groundwater of the Seymour Aquifer, Texas, USA.

    Science.gov (United States)

    Hudak, Paul F

    2008-02-01

    The purpose of this study was to investigate arsenic concentrations in the Seymour Aquifer. Discontinuous alluvium of the aquifer occupies a broad, semi-arid region of northern Texas, USA. Throughout the formation's outcrop, permeable deposits and unconfined conditions may facilitate downward travel of contaminants applied to the land surface. Past agricultural practices are a potential source of arsenic to the aquifer. However, of 64 water samples analyzed from 2001-2004, only one exceeded the maximum contaminant level (MCL) of 10 microg/l for arsenic in drinking water. The median arsenic concentration was 2.7 microg/l, and 34% of samples had arsenic concentrations less than 2 microg/l. No relationship between arsenic concentration and well depth was observed.

  17. Binational Arsenic Exposure Survey: Methodology and Estimated Arsenic Intake from Drinking Water and Urinary Arsenic Concentrations

    OpenAIRE

    Harris, Robin B.; Burgess, Jefferey L; Maria Mercedes Meza-Montenegro; Luis Enrique Gutiérrez-Millán; Mary Kay O’Rourke; Jason Roberge

    2012-01-01

    The Binational Arsenic Exposure Survey (BAsES) was designed to evaluate probable arsenic exposures in selected areas of southern Arizona and northern Mexico, two regions with known elevated levels of arsenic in groundwater reserves. This paper describes the methodology of BAsES and the relationship between estimated arsenic intake from beverages and arsenic output in urine. Households from eight communities were selected for their varying groundwater arsenic concentrations in Arizona, USA and...

  18. Arsenic groundwater contamination and its health effects in Patna district (capital of Bihar) in the middle Ganga plain, India.

    Science.gov (United States)

    Chakraborti, Dipankar; Rahman, Mohammad Mahmudur; Ahamed, Sad; Dutta, Rathindra Nath; Pati, Shyamapada; Mukherjee, Subhash Chandra

    2016-06-01

    We investigated the extent and severity of groundwater arsenic (As) contamination in five blocks in Patna district, Bihar, India along with As in biological samples and its health effects such as dermatological, neurological and obstetric outcome in some villages. We collected 1365 hand tube-well water samples and analyzed for As by the flow injection hydride generation atomic absorption spectrometer (FI-HG-AAS). We found 61% and 44% of the tube-wells had As above 10 and 50 μg/l, respectively, with maximum concentration of 1466 μg/l. Our medical team examined 712 villagers and registered 69 (9.7%) with arsenical skin lesions. Arsenical skin lesions were also observed in 9 children of 312 screened. We analyzed 176 biological samples (hair, nail and urine). Out of these, 69 people had arsenical skin lesions and rest without skin lesions. We found 100% of the biological samples had As above the normal levels (concentrations of As in hair, nail and urine of unexposed individuals usually ranges from 20 to 200 μg/kg, 20-500 μg/kg and Arsenical neuropathy was observed in 40.5% of 37 arsenicosis patients with 73.3% prevalence for predominant sensory neuropathy and 26.7% for sensor-motor. Among patients, different clinical and electrophysiological neurological features and abnormal quantitative sensory perception thresholds were also noted. The study also found that As exposed women with severe skin lesions had adversely affected their pregnancies. People including children in the affected areas are in danger. To combat As situation in affected areas, villagers urgently need (a) provision of As-safe water for drinking and cooking, (b) awareness about the danger of As toxicity, and (c) nutritious food. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Determinants of Arsenicosis Patients’ Perception and Social Implications of Arsenic Poisoning through Groundwater in Bangladesh

    OpenAIRE

    M. Mizanur Rahman Sarker

    2010-01-01

    Adverse human health effects ranging from skin lesions to internal cancers as well as widespread social and psychological problems caused by arsenic contaminated drinking water in Bangladesh may be the biggest arsenic calamity in the world. From an arsenicosis patients survey, this paper empirically analyzes the determinants of arsenicosis patients’ perception about chronic arsenic poisoning and social and psychological implications of arsenicosis. In this study, cross-sectional data were col...

  20. Distribution and hosts of arsenic in a sediment core from the Chianan Plain in SW Taiwan: Implications on arsenic primary source and release mechanisms.

    Science.gov (United States)

    Yang, Huai-Jen; Lee, Chi-Yu; Chiang, Yu-Ju; Jean, Jiin-Shuh; Shau, Yen-Hong; Takazawa, Eiichi; Jiang, Wei-Teh

    2016-11-01

    High arsenic abundance of 50-700μg/L in the groundwater from the Chianan Plain in southwestern Taiwan is a well-known environmental hazard. The groundwater-associated sediments, however, have not been geochemically characterized, thus hindering a comprehensive understanding of arsenic cycling in this region. In this study, samples collected from a 250m sediment core at the centre of the Chianan Plain were analyzed for arsenic and TOC concentrations (N=158), constituent minerals (N=25), major element abundances (N=105), and sequential arsenic extraction (N=23). The arsenic data show a prevalence of >10mg/kg with higher concentrations of 20-50mg/kg concentrated at 60-80 and 195-210m. Arsenic was extracted mainly as an adsorbate on clay minerals, as a co-precipitate in amorphous iron oxyhydroxide, and as a structural component in clay minerals. Since the sediments consist mainly of quartz, chlorite, and illite, the correlations between arsenic concentration and abundances of K2O and MgO pinpoint illite and chlorite as the major arsenic hosts. The arsenic-total iron correlation reflects the role of chlorite along with the contribution from amorphous iron oxyhydroxide as indicated by arsenic extraction data. Organic matter is not the dominant arsenic host for low TOC content, low arsenic abundance extracted from it, and a relatively low R(2) of the arsenic-TOC correlation. The major constituent minerals in the sediments are the same as those of the upriver metapelites, establishing a sink-source relationship. Composition data from two deep groundwater samples near the sediment core show Eh values and As(V)/As(III) ratios of reducing environments and high arsenic, K, Mg, and Fe contents necessary for deriving arsenic from sediments by desorption from clay and dissolution of iron oxyhydroxide. Therefore, groundwater arsenic was mainly derived from groundwater-associated sediments with limited contributions from other sources, such as mud volcanoes.

  1. Treating chronic arsenic toxicity with high selenium lentil diets

    Energy Technology Data Exchange (ETDEWEB)

    Sah, Shweta [Department of Ecosystem and Public Health, Faculty of Medicine, University of Calgary, Calgary, AB T2N 4Z6 (Canada); Vandenberg, Albert [Department of Plant Sciences, University of Saskatchewan, Saskatoon, SK S7N 5A8 (Canada); Smits, Judit, E-mail: judit.smits@ucalgary.ca [Department of Ecosystem and Public Health, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB T2N 4Z6 (Canada)

    2013-10-01

    Arsenic (As) toxicity causes serious health problems in humans, especially in the Indo-Gangetic plains and mountainous areas of China. Selenium (Se), an essential micronutrient is a potential mitigator of As toxicity due to its antioxidant and antagonistic properties. Selenium is seriously deficient in soils world-wide but is present at high, yet non-toxic levels in the great plains of North America. We evaluate the potential of dietary Se in counteracting chronic As toxicity in rats through serum biochemistry, blood glutathione levels, immunotoxicity (antibody response), liver peroxidative stress, thyroid response and As levels in tissues and excreta. To achieve this, we compare diets based on high-Se Saskatchewan (SK) lentils versus low-Se lentils from United States. Rats drank control (0 ppm As) or As (40 ppm As) water while consuming SK lentils (0.3 ppm Se) or northwestern USA lentils (< 0.01 ppm Se) diets for 14 weeks. Rats on high Se diets had higher glutathione levels regardless of As exposure, recovered antibody responses in As-exposed group, higher fecal and urinary As excretion and lower renal As residues. Selenium deficiency caused greater hepatic peroxidative damage in the As exposed animals. Thyroid hormones, triiodothyronine (T3) and thyroxine (T4), were not different. After 14 weeks of As exposure, health indicators in rats improved in response to the high Se lentil diets. Our results indicate that high Se lentils have a potential to mitigate As toxicity in laboratory mammals, which we hope will translate into benefits for As exposed humans. - Highlights: • We reduce chronic arsenic toxicity in rats with a whole food solution. • High selenium lentils decrease liver damage and increase blood glutathione levels. • High selenium lentil diets increase urinary and fecal arsenic excretion. • High selenium lentil diets decrease arsenic levels in kidney, the storage organ. • High selenium lentil diets reverse arsenic suppression of the B cell

  2. Carbon, metals and grain size correlate with bacterial community composition in sediments of a high arsenic aquifer

    Directory of Open Access Journals (Sweden)

    Teresa eLegg

    2012-03-01

    Full Text Available Bacterial communities can exert significant influence on the biogeochemical cycling of arsenic (As. This has globally important implications since As toxicity in drinking water affects the health of millions of people worldwide, including in the Ganges-Brahmaputra Delta region of Bangladesh where geogenic groundwater arsenic concentrations can be more than 10 times the World Health Organization’s limit. Thus, the goal of this research was to investigate patterns in bacterial community composition across environmental gradients in an aquifer with elevated groundwater As concentrations in Araihazar, Bangladesh. We characterized the bacterial community by pyrosequencing 16S rRNA genes from aquifer sediment samples collected at three locations along a groundwater flowpath, at a range of depths between 1.5 and 15 m. We identified significant shifts in bacterial community composition along the groundwater flowpath in the aquifer. In addition, we found that bacterial community structure was significantly related to sediment grain size, and sediment carbon (C, manganese (Mn, and iron (Fe concentrations. Deltaproteobacteria and Chloroflexi were more abundant in silty sediments with higher concentrations of C, Fe, and Mn. By contrast, Alphaproteobacteria and Betaproteobacteria were more abundant in sediments with higher concentrations of sand and Si, and lower concentrations of C and metals. Based on the phylogenetic affiliations of these taxa, these results may indicate a shift to more Fe-, Mn-, and humic substance- reducers in the high C and metal sediments. It is well-documented that C, Mn and Fe may influence the mobility of groundwater arsenic, and it is intriguing that these constituents may also structure the bacterial community.

  3. Recent flow regime and sedimentological evolution of a fluvial system as the main factors controlling spatial distribution of arsenic in groundwater (Red River, Vietnam)

    DEFF Research Database (Denmark)

    Kazmierczak, J.; Larsen, F.; Jakobsen, R.

    2016-01-01

    We investigate a relationship between geological history, groundwater flow paths and the spatial distribution of arsenic in aquifers of the upper part of the Red River delta in Vietnam. Hydrogeological conditions in the research area are complex. The fining upward sequence of Pleistocene alluvial...... sediments was partially eroded during the Holocene and covered by sand and clay deposited in fluvial environments. Sedimentary processes lead to the development of two flow systems. Shallow groundwater discharges either to the local surface water bodies or, in the areas where low permeable sediments...... isolating Pleistocene and Holocene aquifers were eroded, to the deep groundwater flow system discharging to Red River. Previously reported pattern of arsenic groundwater concentrations decreasing with an increasing sediment age is modified by the observed flow regime. Connection of the younger and older...

  4. Detection of trace amount of arsenic in groundwater by laser-induced breakdown spectroscopy and adsorption

    Science.gov (United States)

    Haider, A. F. M. Y.; Hedayet Ullah, M.; Khan, Z. H.; Kabir, Firoza; Abedin, K. M.

    2014-03-01

    LIBS technique coupled with adsorption has been applied for the efficient detection of arsenic in liquid. Several adsorbents like tea leaves, bamboo slice, charcoal and zinc oxide have been used to enable sensitive detection of arsenic presence in water using LIBS. Among these, zinc oxide and charcoal show the better results. The detection limits for arsenic in water were 1 ppm and 8 ppm, respectively, when ZnO and charcoal were used as adsorbents of arsenic. To date, the determination of 1 ppm of As in water is the lowest concentration of detected arsenic in water by the LIBS technique. The detection limit of As was lowered to even less than 100 ppb by a combination of LIBS technique, adsorption by ZnO and concentration enhancement technique. Using the combination of these three techniques the ultimate concentration of arsenic was found to be 0.083 ppm (83 ppb) for arsenic polluted water collected from a tube-well of Farajikandi union (longitude 90.64°, latitude 23.338° north) of Matlab Upozila of Chandpur district in Bangladesh. This result compares fairly well with the finding of arsenic concentration of 0.078 ppm in the sample by the AAS technique at the Bangladesh Council of Scientific and Industrial Research (BCSIR) lab. Such a low detection limit (1 ppm) of trace elements in liquid matrix has significantly enhanced the scope of LIBS as an analytical tool.

  5. Arsenic removal from groundwater by MnO{sub 2}-modified natural clinoptilolite zeolite: Effects of pH and initial feed concentration

    Energy Technology Data Exchange (ETDEWEB)

    Camacho, Lucy M. [Chemical Engineering Department, New Mexico State University, P.O. Box 30001, MSC 3805, 1040 S. Horseshoe St, Las Cruces, NM 88003 (United States); Parra, Ramona R. [Physical Science Laboratory, New Mexico State University, P.O. Box 30001, MSC 3805, Las Cruces, NM 88003 (United States); Deng, Shuguang, E-mail: sdeng@nmsu.edu [Chemical Engineering Department, New Mexico State University, P.O. Box 30001, MSC 3805, 1040 S. Horseshoe St, Las Cruces, NM 88003 (United States)

    2011-05-15

    Adsorption of arsenic (As{sup 5+}) on natural and MnO{sub 2}-modified clinoptilolite-Ca zeolite adsorbents was investigated to explore the feasibility of removing arsenic from groundwater using natural zeolite adsorbents. The natural and MnO{sub 2}-modified clinoptilolite-Ca zeolite adsorbents were characterized with nitrogen adsorption at 77 K for pore textural properties, scanning electron microscopy with energy dispersive X-ray spectroscopy and X-ray fluorescence for morphology, elemental composition and distribution. Batch adsorption equilibrium experiments were conducted to study the effects of pH and initial feed concentration on arsenic removal efficiency. It was found that the amphoteric properties and arsenic removal efficiency of the natural clinoptilolite-Ca zeolite were significantly improved after modification with MnO{sub 2}. The MnO{sub 2}-modified zeolite could effectively remove arsenic from water at a wide pH range, and the arsenic removal efficiency that is basically independent of the pH of feed solutions varies slightly with the initial arsenic concentration in the feed solutions. The removal efficiency obtained on the modified zeolite was doubled as compared to that obtained on the unmodified zeolite. The MnO{sub 2}-modified clinoptilolite-Ca zeolite appears to be a promising adsorbent for removing trace arsenic amounts from water.

  6. Arsenic removal from groundwater by MnO2-modified natural clinoptilolite zeolite: effects of pH and initial feed concentration.

    Science.gov (United States)

    Camacho, Lucy M; Parra, Ramona R; Deng, Shuguang

    2011-05-15

    Adsorption of arsenic (As(5+)) on natural and MnO(2)-modified clinoptilolite-Ca zeolite adsorbents was investigated to explore the feasibility of removing arsenic from groundwater using natural zeolite adsorbents. The natural and MnO(2)-modified clinoptilolite-Ca zeolite adsorbents were characterized with nitrogen adsorption at 77K for pore textural properties, scanning electron microscopy with energy dispersive X-ray spectroscopy and X-ray fluorescence for morphology, elemental composition and distribution. Batch adsorption equilibrium experiments were conducted to study the effects of pH and initial feed concentration on arsenic removal efficiency. It was found that the amphoteric properties and arsenic removal efficiency of the natural clinoptilolite-Ca zeolite were significantly improved after modification with MnO(2). The MnO(2)-modified zeolite could effectively remove arsenic from water at a wide pH range, and the arsenic removal efficiency that is basically independent of the pH of feed solutions varies slightly with the initial arsenic concentration in the feed solutions. The removal efficiency obtained on the modified zeolite was doubled as compared to that obtained on the unmodified zeolite. The MnO(2)-modified clinoptilolite-Ca zeolite appears to be a promising adsorbent for removing trace arsenic amounts from water.

  7. Fact Sheet on Arsenic

    Science.gov (United States)

    Arsenic is a naturally occurring element that is found in combination with either inorganic or organic substances to form many different compounds. Inorganic arsenic compounds are found in soils, sediments, and groundwater.

  8. Study on the variation of arsenic concentration in groundwater and chemical characteristics of arsenic in sediment cores at the areas with endemic arsenic poison disease in Jianghan Plain%江汉平原地方性砷中毒病区地下水砷含量变化及沉积物砷化学特征研究

    Institute of Scientific and Technical Information of China (English)

    周素华; 叶恒朋; 李明健; 熊培生; 杜冬云; 王靖文

    2015-01-01

    目的 了解江汉平原地方性砷中毒(地砷病)病区地下水砷含量变化,探讨该区域高砷水赋存环境、地下水系统砷的来源.方法 在湖北省仙桃市和洪湖市分别以地砷病患者家为中心点,在3km半径内各采集30份地下水样品和3个地质钻孔沉积物样芯;水砷含量比较采用配对t检验或配对符号秩和检验进行分析.结果 仙桃市南洪村2011-2012年水砷浓度低于2006-2007年(t=4.645 3,P<0.000 1),洪湖市姚河村2011-2012年水砷浓度高于2006-2007年(S=-150,P<0.000 1);高砷水呈弱酸、弱氧化性,水砷浓度与水样C1-、HCO3-、Fe、Mn浓度正相关,与水样SO42-、NO3-浓度负相关;研究区沉积物中砷浓度为1.500~ 17.289mg/kg,砷含量最大值均出现在泥土层,最小值均出现在沙层.结论 江汉平原地砷病病区高砷水砷含量的时空间变化程度较大,与中国山西大同盆地、山阴地区、内蒙古河套平原等原生高砷水地区有明显差异,为典型的高砷水赋存环境;研究区沉积物样品中砷含量与岩性结构有密切关系.%Objective To understand the variation of arsenic concentration in underground water at the endemic arsenic poison disease area of Jianghan Plain so as to better understand the spatial distribution of high arsenic groundwater,hydro-chemical evolution and source of arsenic in this region.Methods Thirty underground water samples were collected respectively around 3 km radius of the two houses where arsenic poisoning patients lived,in Xiantao and Honghu.Sediment cores of three drillings were collected as well.Both paired t-test or paired Wilcoxon Signed Ranking Test were used to compare the arsenic concentration of water.Results The arsenic concentration in 2011-2012 appeared lower than that in 2006-2007 at the Nanhong village of Xiantao (t=4.645 3,P<0.000 1),but was higher(S=-150,P<0.000 1) in the Yaohe village of Honghu.The pH value showed weak acidity with Eh as weak oxidated

  9. Co-occurrence perspective of arsenic and fluoride in the groundwater of Diphu, Assam, Northeastern India.

    Science.gov (United States)

    Kumar, Manish; Das, Aparna; Das, Nilotpal; Goswami, Ritusmita; Singh, Umesh Kumar

    2016-05-01

    Considerable lacunae exists in As and F(-) co-contamination investigation in the Brahmaputra and Gangetic floodplains. Therefore we selected Diphu a township in the Karbi Plateau rising from the Brahmaputra floodplains for evaluation of As and F co-occurrence, correlation with coexisting ions of the aquifer system and elucidation of potential processes for releasing As and F(-) in the groundwater. Our initial appraisal used generic plots for identification of hydro geochemical processes and major water types. Subsequently, As and F(-) co-occurrence with pH, depth, HCO3(-), SO4(2-), Ca(2+) and Fe were probed for possible correlation followed by hierarchical cluster analyses to identify key processes for co-occurrence. Finally, saturation indices of groundwater minerals were calculated using MINTEQA2 to elucidate prospective As and F(-) release into groundwater. Results indicate F(-) and As presence in Ca-HCO3 rich water along with positive correlation between Ca(2+) and F(-) possibly due to limestone reserves in adjoining areas. Multivariate analyses suggest the presence of high concentrations of PO4(3-), and H4SiO4 either individually or in combination can enhance the mobility of both As and F(-) and possibly abet conditions conducive for co-contamination of aquifers. Initial release of As and F(-) from the parent rock seems driven by the anthropogenic activities while mobilization depends on chemical interactions and individual affinities of the elements. The results of speciation highlight further mobilization of As and F(-) into the groundwater which in turn require regular attention for sustainable management of scarce water resource present in the area.

  10. Influences on domestic well water testing behavior in a Central Maine area with frequent groundwater arsenic occurrence

    Science.gov (United States)

    Flanagan, Sara V.; Marvinney, Robert G.; Zheng, Yan

    2014-01-01

    In 2001 the Environmental Protection Agency (EPA) adopted a new standard for arsenic (As) in drinking water of 10 μg/L, replacing the old standard of 50 μg/L. However, for the 12% of the U.S. population relying on unregulated domestic well water, including half of the population of Maine, it is solely the well owner’s responsibility to test and treat the water. A mailed household survey was implemented January 2013 in 13 towns of central Maine with the goal of understanding the population’s testing and treatment practices and the key behavior influencing factors in an area with high well-water dependency and frequent natural groundwater As. The response rate was 58.3%; 525 of 900 likely-delivered surveys to randomly selected addresses were completed. Although 78% of the households reported their well has been tested, for half it was more than 5 years ago. Among the 58.7% who believe they have tested for As, most do not remember results. Better educated, higher income homeowners who more recently purchased their homes are most likely to have included As when last testing. While households agree water and As-related health risks can be severe, they feel low personal vulnerability and there are low testing norms overall. Significant predictors of including As when last testing include: having knowledge that years of exposure increases As-related health risks (risk knowledge), knowing who to contact to test well water (action knowledge), believing regularly testing does not take too much time (instrumental attitude), and having neighbors who regularly test their water (descriptive norm). Homeowners in As-affected communities have the tendency to underestimate their As risks compared to their neighbors. The reasons for this optimistic bias require further study, but low testing behaviors in this area may be due to the influence of a combination of norm, ability, and attitude factors and barriers. PMID:24875279

  11. Options of sustainable groundwater supply from safe aquifers in areas with elevated arsenic - a case study from Bangladesh

    Science.gov (United States)

    Jakariya, M.; Bhattacharya, P.; Bromssen, M. V.

    2008-05-01

    Access to safe drinking water is a basic human right. Several millions of people, mainly in developing countries are affected by arsenic in drinking water and the global impact now makes it a top priority water quality issue. A wide gap between the number of exposed people and the pace of mitigation programmes in rural areas of developing countries is the main problem in providing safe drinking water. The main challenge is to develop a sustainable mitigation option that rural and disadvantaged people can adopt and implement themselves to overcome possible public heath hazards. During the recent years, new approaches have emerged in Bangladesh, primarily emerging out of people's own initiative. The local drillers target presumed safe aquifers on the basis of colour and texture of the sediments. A recent study by our research group revealed a distinct correlation between the colour characteristics of the sediments and the groundwater redox conditions. The coupling between the colour of sediments and the redox characteristics of groundwater may thus be used as a tool to assess the risk for As mobilization from the aquifers. The study showed that it is possible to assess the relative risk of high concentrations of As in aquifers if the colour characteristics of the sediments are known and thus, local drillers may target safe aquifers. For validating the sustainability of this mitigation option geological, hydrogeological and microbiological investigations are needed. The sustainability of the aquifers needs to be assessed by combining results from various field and laboratory investigations and by running predictive models. There is also a need to raise the awareness and thereby create a platform for motivating the local drillers to be educated in installing safe tubewells. Awareness raising and community mobilisation are two top priorities for implementing a sustainable safe water project in rural village areas. Significant preparation, attention, and focus must be

  12. Effects of hardness and alkalinity on the removal of arsenic(V) from humic acid-deficient and humic acid-rich groundwater by zero-valent iron.

    Science.gov (United States)

    Mak, Mark S H; Rao, Pinhua; Lo, Irene M C

    2009-09-01

    The effects of hardness (Ca(2+)) and alkalinity (HCO(3)(-)) on arsenic(V) removal from humic acid (HA)-deficient and HA-rich groundwater by zero-valent iron (Fe(0)) were investigated using batch experiments. Arsenic, in general, is removed from groundwater possibly by adsorption and co-precipitation with the iron corrosion products. However, in the co-presence of HCO(3)(-) and Ca(2+), the removal rate of arsenic increased with increasing concentrations of either Ca(2+) or HCO(3)(-). It was observed that the removal of arsenic was significantly enhanced by the formation of CaCO(3) as a nucleation seed for the growth of large iron (hydr)oxide particles. In the co-existence of Ca(2+), HCO(3)(-) and HA, the presence of HA diminished the positive role of Ca(2+) due to the formation of Fe-humate complexes in solution and delaying of the formation of CaCO(3). As a result, the formation of the large iron (hydr)oxide particles was inhibited in the earlier stage which, in turn, affected the removal of arsenic. However, after the formation of CaCO(3) and the subsequent growth of such particles, the presence of large iron (hydr)oxide particles resulted in the rapid removing of arsenic and Fe-humate by adsorption and/or co-precipitation.

  13. Determining the Influence of Groundwater Composition on the Performance of Arsenic Adsorption Columns Using Rapid Small-Scale Column Tests

    Science.gov (United States)

    Aragon, A. R.; Siegel, M.

    2004-12-01

    The USEPA has established a more stringent drinking water standard for arsenic, reducing the maximum contaminant level (MCL) from 50 μ g/L to 10 μ g/L. This will affect many small communities in the US that lack the appropriate treatment infrastructure and funding to reduce arsenic to such levels. For such communities, adsorption systems are the preferred technology based on ease of operation and relatively lower costs. The performance of adsorption media for the removal of arsenic from drinking water is dependent on site-specific water quality. At certain concentrations, co-occurring solutes will compete effectively with arsenic for sorption sites, potentially reducing the sorption capacity of the media. Due to the site-specific nature of water quality and variations in media properties, pilot scale studies are typically carried out to ensure that a proposed treatment technique is cost effective before installation of a full-scale system. Sandia National Laboratories is currently developing an approach to utilize rapid small-scale columns in lieu of pilot columns to test innovative technologies that could significantly reduce the cost of treatment in small communities. Rapid small-scale column tests (RSSCTs) were developed to predict full-scale treatment of organic contaminants by adsorption onto granular activated carbon (GAC). This process greatly reduced the time and costs required to verify performance of GAC adsorption columns. In this study, the RSSCT methodology is used to predict the removal of inorganic arsenic using mixed metal oxyhydroxide adsorption media. The media are engineered and synthesized from materials that control arsenic behavior in natural and disturbed systems. We describe the underlying theory and application of RSSCTs for the performance evaluation of novel media in several groundwater compositions. Results of small-scale laboratory columns are being used to predict the performance of pilot-scale systems and ultimately to design full

  14. Size-fractionation of groundwater arsenic in alluvial aquifers of West Bengal, India: the role of organic and inorganic colloids.

    Science.gov (United States)

    Majumder, Santanu; Nath, Bibhash; Sarkar, Simita; Chatterjee, Debashis; Roman-Ross, Gabriela; Hidalgo, Manuela

    2014-01-15

    Dissolved organic carbon (DOC) and Fe mineral phases are known to influence the mobility of arsenic (As) in groundwater. Arsenic can be associated with colloidal particles containing organic matter and Fe. Currently, no data is available on the dissolved phase/colloidal association of As in groundwater of alluvial aquifers in West Bengal, India. This study investigated the fractional distribution of As (and other metals/metalloids) among the particulate, colloidal and dissolved phases in groundwater to decipher controlling behavior of organic and inorganic colloids on As mobility. The result shows that 83-94% of As remained in the 'truly dissolved' phases (i.e., 0.05 μm size) colloidal particles, which indicates the close association of As with larger Fe-rich inorganic colloids. In smaller (i.e., <0.05 μm size) colloidal particles strong positive correlation is observed between As and DOC (r(2)=0.85), which highlights the close association of As with smaller organic colloids. As(III) is mainly associated with larger inorganic colloids, whereas, As(V) is associated with smaller organic/organometallic colloids. Scanning Electron Microscopy and Energy Dispersive X-ray spectroscopy confirm the association of As with DOC and Fe mineral phases suggesting the formation of dissolved organo-Fe complexes and colloidal organo-Fe oxide phases. Attenuated total reflectance-Fourier transform infrared spectroscopy further confirms the formation of As-Fe-NOM organometallic colloids, however, a detailed study of these types of colloids in natural waters is necessary to underpin their controlling behavior.

  15. Characterization of the extremely arsenic-resistant Brevibacterium linens strain AE038-8 isolated from contaminated groundwater in Tucumán, Argentina

    Science.gov (United States)

    Maizel, Daniela; Blum, Jodi S.; Ferrero, Marcela A.; Utturkar, Sagar M.; Brown, Steven D.; Rosen, Barry P.; Oremland, Ronald S.

    2015-01-01

    Brevibacterium linens AE038-8, isolated from As-contaminated groundwater in Tucumán (Argentina), is highly resistant to arsenic oxyanions, being able to tolerate up to 1 M As(V) and 75 mM As(III) in a complex medium. Strain AE038-8 was also able to reduce As(V) to As(III) when grown in complex medium but paradoxically it could not do this in a defined minimal medium with sodium acetate and ammonium sulfate as carbon and nitrogen sources, respectively. No oxidation of As(III) to As(V) was observed under any conditions. Three copies of the ars operon comprising arsenic resistance genes were found on B. linens AE038-8 genome. In addition to the well known arsC, ACR3 andarsR, two copies of the arsO gene of unknown function were detected.

  16. Arsenic inertization through alunite-type phases: Application to copper pyrometallurgy

    OpenAIRE

    2013-01-01

    [eng] Nowadays, arsenic is an important problem in water pollution. Non-ferrous metallurgical industries generate arsenic residues because the ores contain this mineral. The high technology improvement is increasing the demand of some metals such as copper. This increasing demand and the scarce of copper ores with low arsenic content is generating a problem with arsenic wastes in lots of countries, but especially in Asia and in South and Central America. In these countries, groundwater is pol...

  17. Arsenic contamination in food chain: Thread to food security

    Science.gov (United States)

    Shekhar Azad Kashyap, Chandra; Singh, Swati

    2017-04-01

    The supply of good quality food is a necessity for economic and social health welfare of urban and rural population. Over the last several decades groundwater contamination in developing countries has assumed dangerous levels as a result millions of people are at risk. This is so particularly with respect to arsenic that has registered high concentration in groundwater in countries like India and Bangladesh. The arsenic content in groundwater varies from 10 to 780 µg/L, which is far above the levels for drinking water standards prescribed by World Health Organization (WHO). Currently arsenic has entered in food chain due to irrigation with arsenic contaminated water. In the present study reports the arsenic contamination in groundwater that is being used for irrigating paddy in Manipur and West Bengal. The arsenic content in irrigation water is 475 µg/L and 780 µg/L in Manipur and West Bengal, respectively. In order to assess the effect of such waters on the rice crop, we collected rice plant from Manipur and determined the arsenic content in roots, stem, and grain. The arsenic content in grain varies from 110 to 190 mg/kg while the limit of arsenic intake by humans is 10 mg/kg (WHO). This problem is not confine to the area, it spread global level, and rice being cultivated in these regions is export to the other countries like USA, Middle East and Europe and will be thread to global food security.

  18. Arsenic contamination in food chain: Thread to global food security

    Science.gov (United States)

    Kashyap, C. A.

    2016-12-01

    The supply of good quality food is a necessity for economic and social health of urban and rural population. Over the last several decades groundwater contamination in developing countries has assumed dangerous levels as a result millions of people are at risk. This is so particularly with respect to arsenic that has registered high concentration in groundwater in countries like India and Bangladesh. The arsenic content in groundwater varies from 10 to 780 µg/L, which is far above the levels for drinking water standards prescribed by World Health Organization (WHO). Currently arsenic has entered in food chain due to irrigation with arsenic contaminated water. In the present study reports the arsenic contamination in groundwater that is being used for irrigating paddy in Manipur and West Bengal. The arsenic content in irrigation water is 475 µg/L and 780 µg/L in Manipur and West Bengal, respectively. In order to assess the effect of such waters on the rice crop, we collected rice plant from Manipur and determined the arsenic content in roots, stem, and grain. The arsenic content in grain varies from 110 to 190 mg/kg while the limit of arsenic intake by humans is 10 mg/kg (WHO). This problem is not confine to the area, it spread global level, and rice being cultivated in these regions is export to the other countries like USA, Middle East and Europe and will be thread to global food security.

  19. Effects of redox conditions on the control of arsenic mobility in shallow alluvial aquifers on the Venetian Plain (Italy).

    Science.gov (United States)

    Carraro, A; Fabbri, P; Giaretta, A; Peruzzo, L; Tateo, F; Tellini, F

    2015-11-01

    The Venetian Plain is known for the occurrence of areas with high concentrations of arsenic in groundwater (greater than 400 μg/L). The study area represents the typical residential, industrial and agricultural features of most Western countries and is devoid of hydrothermal, volcanic or anthropogenic sources of arsenic. The aim of the study is to model the arsenic mobilization and the water-rock interaction by a complete hydrogeochemical investigation (analyses of filtered and unfiltered groundwater sediment mineralogy and geochemistry). The groundwater arsenic contamination and redox conditions are highly variable. Groundwaters with oxidizing and strongly reducing potentials have much lower arsenic concentrations than do mildly reducing waters. The grain size of the aquifer sediments includes gravels, sands and silty-clays. A continuous range of organic material concentrations is observed (from zero to 40%). The amount of sedimentary organic matter is highly correlated with the arsenic content of the sediments (up to 300 mg/kg), whereas no relationships are detectable between arsenic and other chemical parameters. The occurrence of arsenic minerals was observed as a peculiar feature under the scanning electron microscope. Arsenic and sulfur are the sole constituents of small tufts or thin crystals concentrated in small masses. These arsenic minerals were clearly observed in the peat sediments, in agreement with the geochemical modeling that requires very reducing conditions for their precipitation from the groundwater. The modeling suggests that, under oxidizing conditions, arsenic is adsorbed; moreover, a continuous decrease in the redox potential causes increasing desorption of arsenic. If the reducing conditions become more intense, the formation of As-S minerals would explain the lower concentration of arsenic measured in the strongly reducing groundwater. Even if As-sulfides are rare under low-temperature conditions, the anomalous abundance of reductants

  20. Spatial Variation of Arsenic in Soil, Irrigation Water, and Plant Parts: A Microlevel Study

    Science.gov (United States)

    Kabir, M. S.; Salam, M. A.; Paul, D. N. R.; Hossain, M. I.; Rahman, N. M. F.; Aziz, Abdullah

    2016-01-01

    Arsenic pollution became a great problem in the recent past in different countries including Bangladesh. The microlevel studies were conducted to see the spatial variation of arsenic in soils and plant parts contaminated through ground water irrigation. The study was performed in shallow tube well command areas in Sadar Upazila (subdistrict), Faridpur, Bangladesh, where both soil and irrigation water arsenic are high. Semivariogram models were computed to determine the spatial dependency of soil, water, grain, straw, and husk arsenic (As). An arsenic concentration surface was created spatially to describe the distribution of arsenic in soil, water, grain, straw, and husk. Command area map was digitized using Arcview GIS from the “mouza” map. Both arsenic contaminated irrigation water and the soils were responsible for accumulation of arsenic in rice straw, husk, and grain. The accumulation of arsenic was higher in water followed by soil, straw, husk, and grain. Arsenic concentration varied widely within command areas. The extent and propensity of arsenic concentration were higher in areas where high concentration of arsenic existed in groundwater and soils. Spherical model was a relatively better and appropriate model. Kriging method appeared to be more suitable in creating interpolated surface. The average arsenic content in grain was 0.08–0.45 mg/kg while in groundwater arsenic level it ranged from 138.0 to 191.3 ppb.

  1. [The establishment of the arsenic poisoning rats model caused by corn flour baked by high-arsenic coal].

    Science.gov (United States)

    Yao, Mao-lin; Zhang, Ai-hua; Yu, Chun; Xu, Yu-yan; Hu, Yong; Xiao, Ting-ting; Wang, Lei

    2013-09-01

    To establish coal arsenic poisoning rat model by feeding the rats with the corn powder baked by high arsenic coal as the main raw material. Fifty Wistar rats, healthy, were randomly divided into 5 groups according to the figures of their weights, including control group, drinking arsenic poisoning water group, low, medium and high arsenic contaminated grain group, 10 rats for each.Rats in control group and drinking arsenic poisoning water group were fed with standard feed without any arsenic containing. Rats in water group would drink 100 mg/L As2O3 solution and the rats in arsenic grain groups would be fed with the arsenic contaminated grain at the dose of 25, 50 and 100 mg/kg, respectively. The duration would last for 3 months.General situation and weight were observed. At the same time, the arsenic contents of urine, hair, liver and kidney of the rats in each group were detected, as well as the histopathology changes of liver and kidney, and the ultra structure of liver was observed. The arsenic contents of urine (median(min-max)) of the rats in the arsenic water group, low, medium and high arsenic grain groups were separately 3055.59 (722.43-6389.05), 635.96(367.85-1551.31), 1453.84 (593.27-5302.94) and 3101.11 (666.64-6858.61) µg/g Cr; while the arsenic contents of hair of the rats in the above groups were separately (23.07 ± 10.38), (8.87 ± 3.31), (12.43 ± 6.65) and (25.68 ± 7.16) µg/g; the arsenic contents of liver of the rats in the above groups were separately (5.68 ± 3.13), (2.64 ± 1.52), (3.89 ± 1.76) and (5.34 ± 2.78) µg/g; and the arsenic contents of kidney were separately (6.90 ± 1.94), (3.48 ± 1.96), (5.03 ± 2.08) and (7.02 ± 1.62) µg/g; which were all significantly higher than those in the control group (86.70 (49.71-106.104) µg/g Cr,(1.28 ± 0.37) µg/g, (1.01 ± 0.34) µg/g and (1.82 ± 1.09) µg/g, respectively). The difference showed significance (P arsenic contaminated grain group. The contents of aspartate transaminase (AST

  2. Geochemistry of aquifer sediments and arsenic-rich groundwaters from Kandal Province, Cambodia

    Energy Technology Data Exchange (ETDEWEB)

    Rowland, Helen A.L.; Gault, Andrew G.; Lythgoe, Paul [School of Earth, Atmospheric and Environmental Sciences and Williamson Research Centre for Molecular Environmental Science, University of Manchester, Manchester M13 9PL (United Kingdom); Polya, David A. [School of Earth, Atmospheric and Environmental Sciences and Williamson Research Centre for Molecular Environmental Science, University of Manchester, Manchester M13 9PL (United Kingdom)], E-mail: david.polya@manchester.ac.uk

    2008-11-15

    Elevated As is well known to be present in aquifers utilised for drinking water and irrigation in West Bengal and Bangladesh. This problem has also more recently been discovered in other parts of Asia, including Vietnam, Cambodia, Inner Mongolia and the Middle Ganges Plain. Analysis of groundwaters in Kandal Province of Cambodia found waters with comparable geochemistry to the As-rich groundwaters of the West Bengali Delta. Similarities included high but heterogeneous As distributions, predominantly in the form As(III), high Fe, moderate to high HCO{sub 3}{sup -}, circumneutral pH, low SO{sub 4}{sup 2-} and geochemical components indicative of reducing conditions. Good positive correlations between As, Fe, HCO{sub 3}{sup -} and NH{sub 4}{sup +}, and dissolved organic C is consistent with As release predominantly via microbially mediated reductive dissolution of As bearing Fe(III) oxides. Further evidence for such a process is found from correlations between As, Fe and organic matter from analysis of aquifer sediments, by the presence of goethite in the finer fractions and from the association of As with amorphous, poorly crystalline and well crystallised hydrous Fe oxides. The presence of several high As, but low Fe, wells implies that microbes could have a more direct role in mediating As release via the direct utilisation of Fe(III) or As(V) as electron acceptors. The presence of elevated As in waters with short aquifer residence times (as indicated by their geochemical signature) highlights the possible vulnerability of these aquifers to the influx of surface derived waters, providing an additional source of labile organic C that could exacerbate As release by stimulating microbial activity.

  3. Reverse Osmosis Filter Use and High Arsenic Levels in Private Well Water

    Science.gov (United States)

    George, Christine M.; Smith, Allan H.; Kalman, David A.; Steinmaus, Craig M.

    2013-01-01

    Inorganic arsenic causes cancer, and millions of people worldwide are exposed to arsenic-contaminated water. Regulatory standards for arsenic levels in drinking water generally do not apply to private domestic wells. Reverse osmosis (RO) units commonly are used by well owners to reduce arsenic concentrations, but may not always be effective. In a survey of 102 homes in Nevada, 19 used RO devices. Pre- and post-RO filtration arsenic concentrations averaged 443 μg/l and 87 μg/l, respectively. The average absolute and percent reductions in arsenic concentrations after filtration were 356 μg/l and 79%, respectively. Postfiltration concentrations were higher than 10 μg/l in 10 homes and higher than 100 μg/l in 4 homes. These findings provide evidence that RO filters do not guarantee safe drinking water and, despite regulatory standards, some people continue to be exposed to very high arsenic concentrations. PMID:17867571

  4. Effects of redox conditions on the control of arsenic mobility in shallow alluvial aquifers on the Venetian Plain (Italy)

    Energy Technology Data Exchange (ETDEWEB)

    Carraro, A. [Institute of Geosciences and Earth Resources, National Research Council (CNR) of Italy, Padova, Italy c/o Department of Geosciences, University of Padova, 35131 Padova (Italy); Fabbri, P. [Institute of Geosciences and Earth Resources, National Research Council (CNR) of Italy, Padova, Italy c/o Department of Geosciences, University of Padova, 35131 Padova (Italy); Department of Geosciences, University of Padova, 35131 Padova (Italy); Giaretta, A.; Peruzzo, L.; Tateo, F.; Tellini, F. [Institute of Geosciences and Earth Resources, National Research Council (CNR) of Italy, Padova, Italy c/o Department of Geosciences, University of Padova, 35131 Padova (Italy)

    2015-11-01

    The Venetian Plain is known for the occurrence of areas with high concentrations of arsenic in groundwater (greater than 400 μg/L). The study area represents the typical residential, industrial and agricultural features of most Western countries and is devoid of hydrothermal, volcanic or anthropogenic sources of arsenic. The aim of the study is to model the arsenic mobilization and the water–rock interaction by a complete hydrogeochemical investigation (analyses of filtered and unfiltered groundwater sediment mineralogy and geochemistry). The groundwater arsenic contamination and redox conditions are highly variable. Groundwaters with oxidizing and strongly reducing potentials have much lower arsenic concentrations than do mildly reducing waters. The grain size of the aquifer sediments includes gravels, sands and silty-clays. A continuous range of organic material concentrations is observed (from zero to 40%). The amount of sedimentary organic matter is highly correlated with the arsenic content of the sediments (up to 300 mg/kg), whereas no relationships are detectable between arsenic and other chemical parameters. The occurrence of arsenic minerals was observed as a peculiar feature under the scanning electron microscope. Arsenic and sulfur are the sole constituents of small tufts or thin crystals concentrated in small masses. These arsenic minerals were clearly observed in the peat sediments, in agreement with the geochemical modeling that requires very reducing conditions for their precipitation from the groundwater. The modeling suggests that, under oxidizing conditions, arsenic is adsorbed; moreover, a continuous decrease in the redox potential causes increasing desorption of arsenic. If the reducing conditions become more intense, the formation of As-S minerals would explain the lower concentration of arsenic measured in the strongly reducing groundwater. Even if As-sulfides are rare under low-temperature conditions, the anomalous abundance of reductants

  5. Do arsenic concentrations in groundwater change over time? A fourteen-year follow-up study of 760 tubewells in Bangladesh

    Science.gov (United States)

    Mailloux, B. J.; Chen, T. L.; van Geen, A.; Bostick, B. C.; Ellis, T.; Ahmed, E. B.; Ahmed, K. M.

    2014-12-01

    Naturally occurring arsenic (As) contamination of shallow groundwater affects numerous tubewells utilized for drinking water in Bangladesh. Long-term exposure to As contaminated water increases the risk of skin lesions and internal cancers. In 2000-2001, water samples from 61 villages distributed within a 25 km area of Araihazar, Bangladesh were collected and tested for As to better understand the spatial distribution of arsenic in groundwater. In 2012, village health workers returned to the same area and performed field kit tests for arsenic and resurveyed well owners. Of the 9,000 tubewells originally sampled in 2000-01, 760 of them have been identified as potentially still in existence by matching GPS coordinates, well depth, and well age information. The goal of this work is to determine whether arsenic concentrations along with groundwater chemistry have changed over the past 14 years in these tubewells. Archived water samples from the 2000-2001 sampling campaign are being assessed for sample storage integrity and village health workers are currently resampling these 760 tubewells. In 2000-2001, these samples were initially analyzed for As using Graphite Furnace Atomic Absorption (GFAA). The 2000-2001 archived water samples are currently being reanalyzed with Inductively Coupled Plasma Mass Spectrometry (ICP-MS) to improve sensitivity, accuracy and precision of arsenic detection. ICP-MS will also be used to analyze for 13 other elements. Comparing ICP-MS with the GFAA As demonstrated that the long-term storage of these samples did not alter the water chemistry. Analysis of the samples currently being collected in Bangladesh will enable us to determine the stability of groundwater chemistry over time.

  6. Comparative survey of bacterial and archaeal communities in high arsenic shallow aquifers using 454 pyrosequencing and traditional methods.

    Science.gov (United States)

    Li, Ping; Jiang, Dawei; Li, Bing; Dai, Xinyue; Wang, Yanhong; Jiang, Zhou; Wang, Yanxin

    2014-12-01

    A survey of bacterial and archaeal community structure was carried out in 10 shallow tube wells in a high arsenic groundwater system located in Hetao Basin, Inner Mongolia by 16S rRNA gene based two-step nested PCR-DGGE, clone libraries and 454 pyrosequencing. 12 bacterial and 18 archaeal DGGE bands and 26-136 species-level OTUs were detected for all the samples. 299 bacterial and 283 archaeal 16S rRNA gene clones for two typical samples were identified by phylogenetic analysis. Most of the results from these different methods were consistent with the dominant bacterial populations. But the proportions of the microbial populations were mostly different and the bacterial communities in most of these samples from pyrosequencing were both more abundant and more diverse than those from the traditional methods. Even after quality filtering, pyrosequencing revealed some populations including Alishewanella, Sulfuricurvum, Arthrobacter, Sporosarcina and Algoriphagus which were not detected with traditional techniques. The most dominant bacterial populations in these samples identified as some arsenic, iron, nitrogen and sulfur reducing and oxidizing related populations including Acinetobacter, Pseudomonas, Flavobacterium, Brevundimonas, Massilia, Planococcus, and Aquabacterium and archaeal communities Nitrosophaera and Methanosaeta. Acinetobacter and Pseudomonas were distinctly abundant in most of these samples. Methanogens were found as the dominant archeal population with three methods. From the results of traditional methods, the dominant archaeal populations apparently changed from phylum Thaumarchaeota to Euryarchaeota with the arsenic concentrations increasing. But this structure dynamic change was not revealed with pyrosequencing. Our results imply that an integrated approach combining the traditional methods and next generation sequencing approaches to characterize the microbial communities in high arsenic groundwater is recommended.

  7. Arsenic levels in immigrant children from countries at risk of consuming arsenic polluted water compared to children from Barcelona.

    Science.gov (United States)

    Piñol, S; Sala, A; Guzman, C; Marcos, S; Joya, X; Puig, C; Velasco, M; Velez, D; Vall, O; Garcia-Algar, O

    2015-11-01

    Arsenic is a highly toxic element that pollutes groundwater, being a major environmental problem worldwide, especially in the Bengal Basin. About 40% of patients in our outpatient clinics come from those countries, and there is no published data about their arsenic exposure. This study compares arsenic exposure between immigrant and native children. A total of 114 children (57 natives, 57 immigrants), aged 2 months to 16 years, were recruited and sociodemographic and environmental exposure data were recorded. Total arsenic in urine, hair, and nails and arsenic-speciated compounds in urine were determined. We did not find significant differences in total and inorganic arsenic levels in urine and hair, but in organic arsenic monomethylarsenic acid (MMA) and dimethylarsinous acid (DMA) in urine and in total arsenic in nails. However, these values were not in the toxic range. There were significant differences between longer than 5 years exposure and less than 5 years exposure (consumption of water from tube wells), with respect to inorganic and organic MMA arsenic in urine and total arsenic in nails. There was partial correlation between the duration of exposure and inorganic arsenic levels in urine. Immigrant children have higher arsenic levels than native children, but they are not toxic. At present, there is no need for specific arsenic screening or follow-up in immigrant children recently arrived in Spain from exposure high-risk countries.

  8. Solar light induced removal of arsenic from contaminated groundwater: the interplay of solar energy and chemical variables

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, M.G.; D' Hiriart, J.; Giullitti, J.; Hidalgo, M. del V. [Universidad Nacional de Tucaman (Argentina). Centro de Investigaciones y Transferencia en Quimica Aplicada; Lin, H.; Custo, G.; Litter, M.I. [Comision Nacional de Energia Atomica, Buenos Aires (Argentina). Unidad de Actividad Quimica; Blesa, M.A. [Comision Nacional de Energia Atomica, Buenos Aires (Argentina). Unidad de Actividad Quimica; Universidad Nacional de General San Martin (Argentina)

    2004-11-01

    The removal of arsenic by solar oxidation in individual units (SORAS) is currently being explored as a possible economic and simple technology to treat groundwater in Bangladesh and India. Hydroarsenicism affects also large regions of America, especially Argentina, Chile, Mexico and Peru. In this paper, the efficiency of arsenic removal by solar oxidation coupled with precipitation of iron (hydr)oxide, was assessed under various experimental conditions, both on samples of synthetic water and of groundwater of the province of Tucuman (Argentina). The results demonstrate that the underlying chemistry is very complex, and the efficiency is affected often in unpredictable ways by changes in the chemical matrix, or by changes in the operative conditions. Oxides generated from ferrous salts are more efficient than solids formed by hydrolysis of Fe(III); alkalinity contents (bicarbonate) is also important to permit the adequate precipitation. Addition of small amounts of citric acid (lemon juice) is beneficial, but at larger concentrations the effect is negative, probably because of interference in the formation of the solid. The effect of solar irradiation is variable, depending on the other experimental conditions. Although it is possible to remove As partially without solar irradiation under certain special conditions, a procedure versatile enough to cope with waters of different compositions must be based in the use of solar energy. Light plays the role of accelerating the oxidation of As(III) to As(V), and also affects the nature of the solid and, hence, its sorptive properties. The rationale of the effect of light is therefore appreciably more complex than in the case of heterogeneous photocatalysis with TiO{sub 2}. (Author)

  9. Removal of arsenic from contaminated groundwater with application of iron electrodissolution, aeration and sand filtration

    DEFF Research Database (Denmark)

    Kowalski, Krysztof; Arturi, Kasia; Søgaard, Erik Gydesen

    2014-01-01

    The results from a new water treatment system for arsenic removal are presented. The technology is based on the employment of an electrolytic iron dissolution and efficient aeration procedure prior to sand filtration. The treatment was introduced and investigated in a pilot scale plant and full...... scale waterworks. The pilot scale results showed a possibility for an efficient arsenic removal from spiked solutions (with As in the range of 50–85 μg/L) depending on the process conditions (flow and applied current). In the waterworks where the system was implemented for a period of 14 months...

  10. Arsenic species in drinking water wells in the USA with high arsenic concentrations.

    Science.gov (United States)

    Sorg, Thomas J; Chen, Abraham S C; Wang, Lili

    2014-01-01

    Arsenic exists in ground water as oxyanions having two oxidation states, As(III) and As(V), and its concentrations vary widely and regionally across the United States (USA). Because of the difference in toxicity and removability of As(III) and As(V), arsenic speciation is important in the selection and design of an arsenic treatment systems. Identifying the arsenic species is also helpful in explaining and understanding the behavior and characteristics of arsenic in the environment. Although laboratory methods exist for speciating arsenic in water samples, the lack of a universal preservation method has led to the predominant use of field separation methods that are somewhat complex and costly. Thus, very few studies have incorporated arsenic speciation. A U.S. Environmental protection Agency (EPA) arsenic treatment research program provided a unique opportunity to speciate the naturally occurring arsenic in 65 well waters scattered across the USA with many of them being speciated monthly for up to three years. Speciation test data showed that 31 wells had predominantly As(V), 29 had predominantly As(III) and five had a mixture of both. A general pattern was found where As(III) was the dominant species in midwest ground waters where anoxic conditions and elevated iron concentrations prevailed and the well waters in the east, west and farwest had either As(III) or As(V) as the dominant species. The monthly (12-36) speciation tests results at many of these sites also found no major changes in arsenic species over time.

  11. Arsenic ototoxicity

    Institute of Scientific and Technical Information of China (English)

    Gulin Gokçen Kesici

    2016-01-01

    High levels of arsenic are found in many parts of the world and more than 100 million people may have been exposed to it. There is growing evidence to indicate that arsenic has a deleterious effect on the auditory system. This paper provides the general information of arsenic and its ototoxic effects.

  12. Earth Abides Arsenic Biotransformations

    Science.gov (United States)

    Zhu, Yong-Guan; Yoshinaga, Masafumi; Zhao, Fang-Jie; Rosen, Barry P.

    2014-05-01

    Arsenic is the most prevalent environmental toxic element and causes health problems throughout the world. The toxicity, mobility, and fate of arsenic in the environment are largely determined by its speciation, and arsenic speciation changes are driven, at least to some extent, by biological processes. In this article, biotransformation of arsenic is reviewed from the perspective of the formation of Earth and the evolution of life, and the connection between arsenic geochemistry and biology is described. The article provides a comprehensive overview of molecular mechanisms of arsenic redox and methylation cycles as well as other arsenic biotransformations. It also discusses the implications of arsenic biotransformation in environmental remediation and food safety, with particular emphasis on groundwater arsenic contamination and arsenic accumulation in rice.

  13. Earth Abides Arsenic Biotransformations

    Science.gov (United States)

    Zhu, Yong-Guan; Yoshinaga, Masafumi; Zhao, Fang-Jie; Rosen, Barry P.

    2015-01-01

    Arsenic is the most prevalent environmental toxic element and causes health problems throughout the world. The toxicity, mobility, and fate of arsenic in the environment are largely determined by its speciation, and arsenic speciation changes are driven, at least to some extent, by biological processes. In this article, biotransformation of arsenic is reviewed from the perspective of the formation of Earth and the evolution of life, and the connection between arsenic geochemistry and biology is described. The article provides a comprehensive overview of molecular mechanisms of arsenic redox and methylation cycles as well as other arsenic biotransformations. It also discusses the implications of arsenic biotransformation in environmental remediation and food safety, with particular emphasis on groundwater arsenic contamination and arsenic accumulation in rice. PMID:26778863

  14. Status of groundwater arsenic contamination in all 17 blocks of Nadia district in the state of West Bengal, India: A 23-year study report

    Science.gov (United States)

    Rahman, Mohammad Mahmudur; Mondal, Debapriya; Das, Bhaskar; Sengupta, Mrinal Kumar; Ahamed, Sad; Hossain, M. Amir; Samal, Alok Chandra; Saha, Kshitish Chandra; Mukherjee, Subhash Chandra; Dutta, Rathindra Nath; Chakraborti, Dipankar

    2014-10-01

    A comprehensive study was conducted in Nadia, one of the nine arsenic (As) affected districts in West Bengal, India to determine the extent and severity of groundwater As contamination and its health effects in particular, dermatological effects and neurological complications. We collected 28,947 hand tube-well water samples from all 17 blocks of Nadia district and analyzed for As by the flow injection-hydride generation atomic absorption spectrometer (FI-HG-AAS). We found 51.4% and 17.3% of the tube-wells had As above 10 and 50 μg/L, respectively and observed that groundwater of all 17 blocks contained As above 50 μg/L with maximum observed level of 3200 μg/L. We estimated that about 2.1 million and 0.6 million people could be drinking As contaminated water above 10 and 50 μg/L, respectively, while 0.048 million could be at risk of drinking As-contaminated water above 300 μg/L, the concentration predicted to cause overt arsenical skin lesions. We screened 15,153 villagers from 50 villages and registered 1077 with arsenical skin lesions resulting in a prevalence rate of 7.1%. Analyzing 2671 biological samples (hair, nail and urine), from people with and without arsenical skin symptoms we found 95% of the samples had As above the normal level, indicating many people in Nadia district are sub-clinically affected. Arsenical neuropathy was observed in 33% of 255 arsenicosis patients with 28.2% prevalence for predominant sensory neuropathy and 4.7% for sensorimotor. As groundwater is still the main source of drinking water, targeting low-As aquifers and switching tube-well from unsafe to nearby safe sources are two visible options to obtain safe drinking water.

  15. Method development for arsenic analysis by modification in spectrophotometric technique

    Directory of Open Access Journals (Sweden)

    M. A. Tahir

    2012-01-01

    Full Text Available Arsenic is a non-metallic constituent, present naturally in groundwater due to some minerals and rocks. Arsenic is not geologically uncommon and occurs in natural water as arsenate and arsenite. Additionally, arsenic may occur from industrial discharges or insecticide application. World Health Organization (WHO and Pakistan Standard Quality Control Authority have recommended a permissible limit of 10 ppb for arsenic in drinking water. Arsenic at lower concentrations can be determined in water by using high tech instruments like the Atomic Absorption Spectrometer (hydride generation. Because arsenic concentration at low limits of 1 ppb can not be determined easily with simple spectrophotometric technique, the spectrophotometric technique using silver diethyldithiocarbamate was modified to achieve better results, up to the extent of 1 ppb arsenic concentration.

  16. Evolution of households’ responses to the groundwater arsenic crisis in Bangladesh: information on environmental health risks can have increasing behavioral impact over time

    Science.gov (United States)

    Balasubramanya, Soumya; Pfaff, Alexander; Bennear, Lori; Tarozzi, Alessandro; Ahmed, Kazi Matin; Schoenfeld, Amy; van Geen, Alexander

    2014-01-01

    A national campaign of well testing through 2003 enabled households in rural Bangladesh to switch, at least for drinking, from high-arsenic wells to neighboring lower-arsenic wells. We study the well-switching dynamics over time by re-interviewing, in 2008, a randomly selected subset of households in the Araihazar region who had been interviewed in 2005. Contrary to concerns that the impact of arsenic information on switching behavior would erode over time, we find that not only was 2003–2005 switching highly persistent but also new switching by 2008 doubled the share of households at unsafe wells who had switched. The passage of time also had a cost: 22% of households did not recall test results by 2008. The loss of arsenic knowledge led to staying at unsafe wells and switching from safe wells. Our results support ongoing well testing for arsenic to reinforce this beneficial information. PMID:25383015

  17. Groundwater.

    Science.gov (United States)

    Braids, Olin C.; Gillies, Nola P.

    1978-01-01

    Presents a literature review of groundwater quality covering publications of 1977. This review includes: (1) sources of groundwater contamination; and (2) management of groundwater. A list of 59 references is also presented. (HM)

  18. Culturable associated-bacteria of the sponge Theonella swinhoei show tolerance to high arsenic concentrations

    Directory of Open Access Journals (Sweden)

    Ray eKeren

    2015-02-01

    Full Text Available Sponges are potent filter feeders and as such are exposed to high fluxes of toxic trace elements, which can accumulate in their body over time. Such is the case of the Red Sea sponge Theonella swinhoei, which has been shown to accumulate up to 8500 mg/Kg of the highly toxic element arsenic. T. swinhoei is known to harbor a multitude of sponge-associated bacteria, so it is hypothesized that the associated-bacteria will be tolerant to high arsenic concentration. This study also investigates the fate of the arsenic accumulated in the sponge to test if the associated-bacteria have an important role in the arsenic accumulation process of their host, since bacteria are key players in the natural arsenic cycle. Separation of the sponge to sponge cells and bacteria enriched fractions showed that arsenic is accumulated by the bacteria. Sponge-associated, arsenic-tolerant bacteria were cultured in the presence of 5 mM of either arsenate or arsenite (equivalent to 6150 mg/Kg arsenic, dry weight. The 54 isolated bacteria were grouped to 15 OTUs and isolates belonging to 12 OTUs were assessed for tolerance to arsenate at increased concentrations up to 100 mM. Eight of the 12 OTUs tolerated an order of magnitude increase in the concentration of arsenate, and some exhibited external biomineralization of arsenic-magnesium salts. The biomineralization of this unique mineral was directly observed in bacteria for the first time. These results may provide an explanation for the ability of the sponge to accumulate considerable amounts of arsenic. Furthermore arsenic-mineralizing bacteria can potentially be used for the study of bioremediation, as arsenic toxicity affects millions of people worldwide.

  19. Arsenic methylation patterns before and after changing from high to lower concentrations of arsenic in drinking water.

    Science.gov (United States)

    Hopenhayn-Rich, C; Biggs, M L; Kalman, D A; Moore, L E; Smith, A H

    1996-01-01

    Inorganic arsenic (In-As), an occupational and environmental human carcinogen, undergoes biomethylation to monomethylarsonate (MMA) and dimethylarsinate (DMA). It has been proposed that saturation of methylation capacity at high exposure levels may lead to a threshold for the carcinogenicity of In-As. The relative distribution of urinary In-As, MMA, and DMA is used as a measure of human methylation capacity. The most common pathway for elevated environmental exposure to In-As worldwide is through drinking water. We conducted a biomarker study in northern Chile of a population chronically exposed to water naturally contaminated with high arsenic content (600 micrograms/l). In this paper we present the results of a prospective follow-up of 73 exposed individuals, who were provided with water of lower arsenic content (45 micrograms/l) for 2 months. The proportions of In-As, MMA, and DMA in urine were compared before and after intervention, and the effect of other factors on the distribution of arsenic metabolites was also analyzed. The findings of this study indicate that the decrease in arsenic exposure was associated with a small decrease in the percent In-As in urine (from 17.8% to 14.6%) and in the MMA/DMA ratio (from 0.23 to 0.18). Other factors such as smoking, gender, age, years of residence, and ethnicity were associated mainly with changes in the MMA/DMA ratio, with smoking having the strongest effect. Nevertheless, the factors investigated accounted for only about 20% of the large interindividual variability observed. Genetic polymorphisms in As-methylating enzymes and other co-factors are likely to contribute to some of the unexplained variation. The changes observed in the percent In-As and in the MMA/DMA ratio do not support an exposure-based threshold for arsenic methylation in humans. Images Figure 1. A Figure 1. B Figure 2. A Figure 2. B PMID:8959409

  20. Chronic subhepatotoxic exposure to arsenic enhances hepatic injury caused by high fat diet in mice

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Min; Schmidt, Robin H.; Beier, Juliane I. [Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, KY 40292 (United States); Department of Medicine, University of Louisville Health Sciences Center, Louisville, KY 40292 (United States); Watson, Walter H. [Department of Medicine, University of Louisville Health Sciences Center, Louisville, KY 40292 (United States); University of Louisville Alcohol Research Center, University of Louisville Health Sciences Center, Louisville, KY 40292 (United States); Zhong, Hai [Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, KY 40292 (United States); University of Louisville Alcohol Research Center, University of Louisville Health Sciences Center, Louisville, KY 40292 (United States); States, J. Christopher [Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, KY 40292 (United States); Arteel, Gavin E., E-mail: gavin.arteel@louisville.edu [Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, KY 40292 (United States); University of Louisville Alcohol Research Center, University of Louisville Health Sciences Center, Louisville, KY 40292 (United States)

    2011-12-15

    Arsenic is a ubiquitous contaminant in drinking water. Whereas arsenic can be directly hepatotoxic, the concentrations/doses required are generally higher than present in the US water supply. However, physiological/biochemical changes that are alone pathologically inert can enhance the hepatotoxic response to a subsequent stimulus. Such a '2-hit' paradigm is best exemplified in chronic fatty liver diseases. Here, the hypothesis that low arsenic exposure sensitizes liver to hepatotoxicity in a mouse model of non-alcoholic fatty liver disease was tested. Accordingly, male C57Bl/6J mice were exposed to low fat diet (LFD; 13% calories as fat) or high fat diet (HFD; 42% calories as fat) and tap water or arsenic (4.9 ppm as sodium arsenite) for ten weeks. Biochemical and histologic indices of liver damage were determined. High fat diet ({+-} arsenic) significantly increased body weight gain in mice compared with low-fat controls. HFD significantly increased liver to body weight ratios; this variable was unaffected by arsenic exposure. HFD caused steatohepatitis, as indicated by histological assessment and by increases in plasma ALT and AST. Although arsenic exposure had no effect on indices of liver damage in LFD-fed animals, it significantly increased the liver damage caused by HFD. This effect of arsenic correlated with enhanced inflammation and fibrin extracellular matrix (ECM) deposition. These data indicate that subhepatotoxic arsenic exposure enhances the toxicity of HFD. These results also suggest that arsenic exposure might be a risk factor for the development of fatty liver disease in human populations. -- Highlights: Black-Right-Pointing-Pointer Characterizes a mouse model of arsenic enhanced NAFLD. Black-Right-Pointing-Pointer Arsenic synergistically enhances experimental fatty liver disease at concentrations that cause no overt hepatotoxicity alone. Black-Right-Pointing-Pointer This effect is associated with increased inflammation.

  1. A study of lipid- and water-soluble arsenic species in liver of Northeast Arctic cod (Gadus morhua) containing high levels of total arsenic

    DEFF Research Database (Denmark)

    Sele, Veronika; Sloth, Jens Jørgen; Julshamn, Kale;

    2015-01-01

    In the present study liver samples (n = 26) of Northeast Arctic cod (Gadus morhua), ranging in total arsenic concentrations from 2.1 to 240 mg/kg liver wet weight (ww), were analysed for their content of total arsenic and arsenic species in the lipid-soluble and water-soluble fractions. The arsenic...... concentrations in the lipid fractions ranged from 1.8 to 16.4 mg As/kg oil of liver, and a linear correlation (r(2) = 0.80, p arsenic concentrations in liver and the total arsenic concentrations in the respective lipid fractions of the same livers. The relative proportion...... of arsenolipids was considerably lower in liver samples with high total arsenic levels (33-240 mg/kg ww), which contained from 3 to 7% of the total arsenic in the lipid-soluble fraction. In contrast liver samples with low arsenic concentrations (2.1-33 mg/kg ww) contained up to 50% of the total arsenic as lipid...

  2. Arsenic in Groundwater: The Deep Late Pleistocene Aquifers of the Western Bengal Basin.

    Science.gov (United States)

    McArthur, J M; Ghosal, U; Sikdar, P K; Ball, J D

    2016-04-05

    in groundwaters from 145 wells across central West Bengal, India, those from Pleistocene aquifers at depths >70 m beneath paleo-interfluves contain aquifers beneath deep paleo-channels typically host groundwaters containing 10-100 μg/L As at depths between 120 and 180 m. The depth profiles of As and SO4 and the conservative tracers Cl/Br, δ(18)O, and δ(2)H show that the As in Pleistocene groundwater beneath deep paleo-channels is relict and does not arise from migration downward of As-polluted groundwater in overlying aquifers. We postulate that the As was liberated in situ by reduction of minimal iron oxyhydroxides in the gray Pleistocene sands by organic matter infiltrating from riverbeds during late Pleistocene or earliest Holocene times. Mitigation of the widespread As-pollution in shallow aquifers through exploitation of deep Pleistocene aquifers would improve if guided by an understanding of the distribution of buried paleo-channels and paleo-interfluves and the knowledge that As may be present naturally in groundwater at depths >150 m beneath deep paleo-channels.

  3. The origin of groundwater arsenic and fluorine in a volcanic sedimentary basin in central Mexico: a hydrochemistry hypothesis

    Science.gov (United States)

    Morales-Arredondo, Iván; Rodríguez, Ramiro; Armienta, Maria Aurora; Villanueva-Estrada, Ruth Esther

    2016-06-01

    A groundwater sampling campaign was carried out in the summer of 2013 in a low-temperature geothermal system located in Juventino Rosas (JR) municipality, Guanajuato State, Mexico. This groundwater presents high concentrations of As and F- and high Rn counts, mainly in wells with relatively higher temperature. The chemistry of major elements was interpreted with different methods, like Piper and D'Amore diagrams. These diagrams allowed for classification of four groundwater types located in three hydrogeological environments. The aquifers are hosted mainly in alluvial-lacustrine sediments and volcanic rocks in interaction with fault and fracture systems. The subsidence, faults and fractures observed in the study area can act as preferential channels for recharge and also for the transport of deep fluids to the surface, especially in the basin plain. The formation of a piezometric dome and the observed hydrochemical behavior of groundwater suggest a possible origin of the As and F-. Geochemical processes occurring during water-rock interaction are related to high concentrations of As and F-. High temperatures and alteration processes (like rock weathering) induce dissolution of As and F--bearing minerals, increasing the content of these elements in groundwater.

  4. Total coliforms, arsenic and cadmium exposure through drinking water in the Western Region of Ghana: application of multivariate statistical technique to groundwater quality.

    Science.gov (United States)

    Affum, Andrews Obeng; Osae, Shiloh Dede; Nyarko, Benjamin Jabez Botwe; Afful, Samuel; Fianko, Joseph Richmond; Akiti, Tetteh Thomas; Adomako, Dickson; Acquaah, Samuel Osafo; Dorleku, Micheal; Antoh, Emmanuel; Barnes, Felix; Affum, Enoch Acheampong

    2015-02-01

    In recent times, surface water resource in the Western Region of Ghana has been found to be inadequate in supply and polluted by various anthropogenic activities. As a result of these problems, the demand for groundwater by the human populations in the peri-urban communities for domestic, municipal and irrigation purposes has increased without prior knowledge of its water quality. Water samples were collected from 14 public hand-dug wells during the rainy season in 2013 and investigated for total coliforms, Escherichia coli, mercury (Hg), arsenic (As), cadmium (Cd) and physicochemical parameters. Multivariate statistical analysis of the dataset and a linear stoichiometric plot of major ions were applied to group the water samples and to identify the main factors and sources of contamination. Hierarchal cluster analysis revealed four clusters from the hydrochemical variables (R-mode) and three clusters in the case of water samples (Q-mode) after z score standardization. Principal component analysis after a varimax rotation of the dataset indicated that the four factors extracted explained 93.3 % of the total variance, which highlighted salinity, toxic elements and hardness pollution as the dominant factors affecting groundwater quality. Cation exchange, mineral dissolution and silicate weathering influenced groundwater quality. The ranking order of major ions was Na(+) > Ca(2+) > K(+) > Mg(2+) and Cl(-) > SO4 (2-) > HCO3 (-). Based on piper plot and the hydrogeology of the study area, sodium chloride (86 %), sodium hydrogen carbonate and sodium carbonate (14 %) water types were identified. Although E. coli were absent in the water samples, 36 % of the wells contained total coliforms (Enterobacter species) which exceeded the WHO guidelines limit of zero colony-forming unit (CFU)/100 mL of drinking water. With the exception of Hg, the concentration of As and Cd in 79 and 43 % of the water samples exceeded the WHO guideline limits of 10 and 3

  5. Arsenic content in groundwater from the southern part of the San Antonio-El Triunfo mining district, Baja California Sur, Mexico

    Science.gov (United States)

    Wurl, Jobst; Mendez-Rodriguez, Lía; Acosta-Vargas, Baudilio

    2014-10-01

    The San Antonio-El Triunfo mining district is located in a mountain region 60 km southeast of La Paz, the capital of the Mexican state of Baja California Sur. Mining activities, focused on gold and silver extraction, which began in the second half of the 18th century; the main activity took place between 1878 and 1911. The minerals were treated through the cyanide method, burned, and smelted. In effect between 800,000 and 1 million tons of mine waste materials were scattered in an area of approximately 350-400 km2. This area contains today several byproducts as a result from arsenopyrite oxidation, such as arsenolite (As2O3). The aim of this study was to analyze groundwater composition in order to define the actual concentrations of relevant parameters to detect ore mining contaminations, especially in respect to arsenic. In the autumn of 2010, 29 groundwater samples were obtained using flow-through bailer or down-hole pump methods, and a total of 37 variables were measured in each sample. Arsenic (dissolved) exceeded the values established by the World Health Organization (WHO, 2011) (0.01 mg/L) in 41% of the monitored sites. The maximum concentration of arsenic found in one observation well was 0.45 mg/L. Four water samples, which were characterized by elevated concentration of boron (max. conc. 9.5 mg/L), fluoride (max. conc. 3.25 mg/L) and alkaline pH values (>9), showed a composition typical for hydrothermal water. Because all four samples had arsenic concentration under 0.008 mg/L, we conclude that no significant impact of arsenic from hydrothermal fluids is found in the study area.

  6. Vulsino volcanic aquifer in Umbria Region : Hydrogeological survey for the characterization of the presence of arsenic and aluminium and the correct use of groundwater

    Directory of Open Access Journals (Sweden)

    Stefano Fratini

    2013-12-01

    Full Text Available In December 2009 and the first months of 2010, a large water crisis took place in the Orvieto area, because of sudden high concentration of aluminum (Al in the groundwater of the vulsino aquifer. This represents a supply for Orvieto’s population and other near municipalities (about 20,000 people. The contamination had reached values of about 3000 μg/l. Water crisis was made worse because of the expiring, in the same period, as expected, of the derogation of European Commission that allowed Arsenic concentrations above 10 μg/l (up to 50 μg/l. The contamination by Al occurred after intense and persistent rains, that mobilized a large amount of aluminum hydroxides in perched water table, in the form of colloidal particles. The field analysis showed that the potable water catchments are not interested in the same way by the contamination, i.e. the vulsino aquifer was not wholly conditioned by the presence of Al; in addition, in the same period in which the Al contamination occurred, there were no changes in the levels of As in groundwater. This paper shows the study of the complex hydrogeological Vulsino system; the aim is to identify technical solutions for realizing new catchments in order to manage the resource, in qualitative and quantitative terms, replacing/integrating the current equipments, which represent a risk because of the presence of Al and, secondly, As. A numerical flow and transport model was implemented to support the hydrogeological study, that has allowed us to formulate reliable predictions regarding the risk of Al contamination of future new wells.

  7. Occurrence and geochemical behavior of arsenic in a coastal aquifer-aquitard system of the Pearl River Delta, China

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ya [Department of Earth Sciences, The University of Hong Kong, Hong Kong (China); Jiao, Jiu Jimmy, E-mail: jjiao@hku.hk [Department of Earth Sciences, The University of Hong Kong, Hong Kong (China); Cherry, John A. [School of Engineering, University of Guelph, Guelph, ON, Canada N1G 2W1 (Canada)

    2012-06-15

    Elevated concentrations of arsenic, up to 161 {mu}g/L, have been identified in groundwater samples from the confined basal aquifer underlying the aquitard of the Pearl River Delta (PRD). Both aquatic arsenic in pore water and solid arsenic in the sediments in the basal aquifer and aquitard were identified. Arsenic speciation of groundwater in the basal aquifer was elucidated on a pH-Eh diagram. In the PRD, arsenic is enriched in groundwater having both low and high salinity, and arsenic enriched groundwater is devoid of dissolved oxygen, has negative Eh values, is slightly alkaline, and has abnormally high concentrations of ammonium and dissolved organic carbon, but low concentrations of nitrate and nitrite. Results of geochemical and hydrochemical analyses and sequential extraction analysis suggest that reductive dissolution of iron oxyhydroxide could be one of the important processes that mobilized solid arsenic. We speculate that mineralization of sedimentary organic matter could also contribute to aquatic arsenic. Scanning electron microscope analysis confirms that abundant authigenic pyrite is present in the sediments. Sulphate derived from paleo-seawater served as the important sulfur source for authigenic pyrite formation. Co-precipitation of arsenic with authigenic pyrite significantly controlled concentrations of aquatic arsenic in the coastal aquifer-aquitard system. - Highlights: Black-Right-Pointing-Pointer Coastal aquifer and aquitard are treated as an integrate system. Black-Right-Pointing-Pointer Both aquatic arsenic and solid arsenic are observed. Black-Right-Pointing-Pointer Aquatic arsenic is derived from reductive dissolution of iron oxyhydroxide. Black-Right-Pointing-Pointer Aquatic arsenic can also derived from mineralization of sedimentary organic matter. Black-Right-Pointing-Pointer Co-precipitation of arsenic with authigenic pyrite is significant in such a system.

  8. A cross sectional study of anemia and iron deficiency as risk factors for arsenic-induced skin lesions in Bangladeshi women

    OpenAIRE

    Kile, Molly L.; Faraj, Joycelyn M.; Ronnenberg, Alayne G.; Quamruzzaman, Quazi; Rahman, Mahmudar; Mostofa, Golam; Afroz, Sakila; Christiani, David C.

    2016-01-01

    Background In the Ganges Delta, chronic arsenic poisoning is a health concern affecting millions of people who rely on groundwater as their potable water source. The prevalence of anemia is also high in this region, particularly among women. Moreover, arsenic is known to affect heme synthesis and erythrocytes and the risk of arsenic-induced skin lesions appears to differ by sex. Methods We conducted a case-control study in 147 arsenic-exposed Bangladeshi women to assess the association betwee...

  9. A cross sectional study of anemia and iron deficiency as risk factors for arsenic-induced skin lesions in Bangladeshi women

    OpenAIRE

    Kile, Molly L; Faraj, Joycelyn M.; Ronnenberg, Alayne G; Quamruzzaman, Quazi; Rahman, Mahmudar; Mostofa, Golam; Afroz, Sakila; Christiani, David C.

    2016-01-01

    Background: In the Ganges Delta, chronic arsenic poisoning is a health concern affecting millions of people who rely on groundwater as their potable water source. The prevalence of anemia is also high in this region, particularly among women. Moreover, arsenic is known to affect heme synthesis and erythrocytes and the risk of arsenic-induced skin lesions appears to differ by sex. Methods: We conducted a case-control study in 147 arsenic-exposed Bangladeshi women to assess the association betw...

  10. Speciation of arsenic using chelation solvent extraction and high performance liquid chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Cathum, Shamil J.; Obenauf, Alison; Punt, Monique [SAIC Canada, Ottawa, Ontario (Canada); Brown, Carl E. [Emergencies Engineering Technology Office, Environmental Technology Centre, Environment Canada, Ottawa, Ontario (Canada)

    2007-02-15

    Research interest in speciation of arsenic stems from its species dependent behavior in the environment and in living organisms. The complexity of the matrix to be analyzed and low concentrations of target arsenic species that may be labile or difficult to chromatogram, indicate that a suitable pre-treatment methodology is required. This study investigated the usefulness of chelation solvent extraction - high performance liquid chromatography (CSE-HPLC) for the speciation of arsenic in water. It involved reacting arsenic with the chelant known for its affinity towards arsenic, followed by extraction, separation, and identification of the arsenic-chelant-arsenic complex. Arsenic species having different physicochemical properties were investigated. Species, such as, As{sub 2}O{sub 3}, As{sub 3}O{sub 5}, KH{sub 2}AsO{sub 4}, Na{sub 2}HAsO{sub 4}, and NaAsO{sub 2}were detected as a group of closely eluted peaks with different retention times and spectral properties, whereas, the organic arsenic species CH {sub 3}Na {sub 2}AsO {sub 3}, o-arsanilic acid, roxarson and triphenyl arsine separated quite well on the EnviroseP-CM HPLC column. Key method parameters, such as, type of HPLC column, composition of mobile phase and organic solvents affecting peak resolution and sensitivity were optimized. Real environmental matrices contaminated with arsenic were analyzed under varying wavelengths ({lambda}{sub max} = 190, 210, 220, 234, 244, and 282 nm), with good precision. Different arsenic species were detected in these samples with excellent background and signal-to-noise ratios demonstrating the robustness of the method. The detection limit, reproducibility, selectivity, accuracy, and dynamic range of the calibration curves were evaluated. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  11. Adsorptive properties of alluvial soil for arsenic(V) and its potential for protection of the shallow groundwater among Changsha, Zhuzhou, and Xiangtan cities, China.

    Science.gov (United States)

    Chen, Hongwei; Mei, Jinhua; Luo, Yueping; Qiu, Anni; Wang, Huan

    2017-02-01

    The study area is among Changsha, Zhuzhou, and Xiangtan cities, which was under agricultural use and natural conditions about 10 years ago and now is becoming part of the metropolis because of the urban expansion. This study aims to investigate the mechanisms and capabilities of the local alluvial soil layer for protecting the local shallow groundwater from arsenic pollution by field surveys and batch experiments. The field surveys showed that there was an acidic tendency of the groundwater, and phosphate, nitrate, and arsenic in the groundwater significantly increased comparing to their reference values. It indicates that the disturbance of the former agricultural land due to the change of land use may be responsible for these changes. From the experimental results, the maximum adsorption capacity of the soil for As(V) was as low as 0.334 mg/g, and lower As(V) adsorption capacities were obtained at higher As(V) concentration, higher pH, and lower temperature. The presence of H2PO4(-) and SiO3(2-) posed negative, while HCO3(-) slight positive, and SO4(2-), NO3(-) and Cl(-) negligible influences on the As(V) adsorption. The surface-derived organic matter played a negative role in the adsorption process, and low specific surface area influenced adsorption capacity of the soil. The study reveals that the local soil layer shows poor potential for protection of the local shallow groundwater from As(V) pollution, and the change trends of the groundwater environments due to more intensive anthropogenic activities will further weaken this potential and increase the risk of the groundwater contamination.

  12. Arsenic contamination in the Kanker district of central-east India: geology and health effects.

    Science.gov (United States)

    Pandey, P K; Sharma, R; Roy, M; Roy, S; Pandey, M

    2006-10-01

    This paper identifies newer areas of arsenic contamination in the District Kanker, which adjoins the District Rajnandgaon where high contamination has been reported earlier. A correlation with the mobile phase episodes of arsenic contamination has been identified, which further hinges on the complex geology of the area. Arsenic concentrations in both surface and groundwater, aquatic organisms (snail and water weeds) soil and vegetation of Kanker district and its adjoining area have been reported here. The region has been found to contain an elevated level of arsenic. All segments of the ecoysystem are contaminated with arsenic at varying degrees. The levels of arsenic vary constantly depending on the season and location. An analysis of groundwater from 89 locations in the Kanker district has shown high values of arsenic, iron and manganese (mean: 144, 914 and 371 microg L(-1), respectively). The surface water of the region shows elevated levels of arsenic, which is influenced by the geological mineralised zonation. The most prevalent species in the groundwater is As(III), whereas the surface water of the rivers shows a significant contamination with the As(V) species. The analysis shows a bio-concentration of the toxic metals arsenic, nickel, copper and chromium. Higher arsenic concentrations (groundwater concentrations greater than 50 microg L(-1)) are associated with sedimentary deposits derived from volcanic rocks, hence mineral leaching appears to be the source of arsenic contamination. Higher levels of arsenic and manganese in the Kanker district have been found to cause impacts on the flora and fauna. A case study of episodic arsenical diarrhoea is presented.

  13. Survey of total and inorganic arsenic content in blue mussels (Mytilus edulis L.) from Norwegian fiords: Revelation of unusual high levels of inorganic arsenic

    DEFF Research Database (Denmark)

    Sloth, Jens Jørgen; Julshamn, Kåre

    2008-01-01

    The present study reports the findings of unusual high levels of inorganic arsenic in samples of blue mussels (Mytilus edulis L.). A total of 175 pooled samples of blue mussels from various locations along the Norwegian coastline were analyzed for their content of total arsenic and inorganic...

  14. Family aggregation in a population of chronic arsenic poisoning associated with high arsenic coal burning

    Institute of Scientific and Technical Information of China (English)

    LinGF; ChenJG

    2002-01-01

    About 2600 cases of chronic arsenic poisoning (CAP) in Southwest China-Guizhou Povince represent a unique case of CAP in the world associated with indoor high As coal burning.An epidemiological investigation in 4 clans (694 subjects,male 299,female 395) was launched in one Cun(village) in JL area(21000 residents,about 2000 CAP cases).(1)Clan G(possible Hanized Yi origin).The ancestors,a couple settled here in Qing dynasty.CAP prevalence was 43.3%(93/215).It was found that in 9 of 25 brotherhood groups all the members suffered with CAP.(2) An non-consanguinous branch of family G.The ancestor,a boy was adopted by family G in 1890s.The incidence rate was 20.8%(11/53) which was lower than that in clan G(consanguineous)(P=0.00261,r=0.344),though both clans have been living in the same family for 4 generations.(3)Clan B(Han origin).The ancestor moved the family from Nanjing in Ming dynasty.The CAP prevalence is 45.5%(75/165).(4)Clan P(ethnic Miao).The CAP prevalence is 3.9(9/232),far less than other ethnic clans,for example,less than clan G (consanguineous)(P=3.706E=23,r=0.052944).The observation suggests possible family aggregation of CAP in high As coal using area.further work is required.

  15. Arsenic and iron removal from groundwater by oxidation–coagulation at optimized pH: Laboratory and field studies

    Energy Technology Data Exchange (ETDEWEB)

    Bordoloi, Shreemoyee; Nath, Suresh K.; Gogoi, Sweety; Dutta, Robin K., E-mail: robind@tezu.ernet.in

    2013-09-15

    Highlights: • Arsenic and iron removed by a systematic oxidation–coagulation at optimized pH. • Used KMnO{sub 4} as oxidant and FeCl{sub 3} as coagulant in presence of NaHCO{sub 3}. • Field trial results are highly encouraging. • The method is efficient, safe, simple and low-cost. • The method is suitable for rural application in developing countries. -- Abstract: A three-step treatment process involving (i) mild alkaline pH-conditioning by NaHCO{sub 3}; (ii) oxidation of arsenite and ferrous ions by KMnO{sub 4}, itself precipitating as insoluble MnO{sub 2} under the pH condition; and (iii) coagulation by FeCl{sub 3} has been used for simultaneous removal of arsenic and iron ions from water. The treated water is filtered after a residence time of 1–2 h. Laboratory batch experiments were performed to optimize the doses. A field trial was performed with an optimized recipe at 30 households and 5 schools at some highly arsenic affected villages in Assam, India. Simultaneous removals of arsenic from initial 0.1–0.5 mg/L to about 5 μg/L and iron from initial 0.3–5.0 mg/L to less than 0.1 mg/L have been achieved along with final pH between 7.0 and 7.5 after residence time of 1 h. The process also removes other heavy elements, if present, without leaving any additional toxic residue. The small quantity of solid sludge containing mainly ferrihydrite with adsorbed arsenate passes the toxicity characteristic leaching procedure (TCLP) test. The estimated recurring cost is approximately USD 0.16 per/m{sup 3} of purified water. A high efficiency, an extremely low cost, safety, non-requirement of power and simplicity of operation make the technique potential for rural application.

  16. Estimating the effectiveness of health-risk communications with propensity-score matching: application to arsenic groundwater contamination in four US locations.

    Science.gov (United States)

    Leidner, Andrew J

    2014-01-01

    This paper provides a demonstration of propensity-score matching estimation methods to evaluate the effectiveness of health-risk communication efforts. This study develops a two-stage regression model to investigate household and respondent characteristics as they contribute to aversion behavior to reduce exposure to arsenic-contaminated groundwater. The aversion activity under study is a household-level point-of-use filtration device. Since the acquisition of arsenic contamination information and the engagement in an aversion activity may be codetermined, a two-stage propensity-score model is developed. In the first stage, the propensity for households to acquire arsenic contamination information is estimated. Then, the propensity scores are used to weight observations in a probit regression on the decision to avert the arsenic-related health risk. Of four potential sources of information, utility, media, friend, or others, information received from a friend appears to be the source of information most associated with aversion behavior. Other statistically significant covariates in the household's decision to avert contamination include reported household income, the presence of children in household, and region-level indicator variables. These findings are primarily illustrative and demonstrate the usefulness of propensity-score methods to estimate health-risk communication effectiveness. They may also be suggestive of areas for future research.

  17. Estimating the Effectiveness of Health-Risk Communications with Propensity-Score Matching: Application to Arsenic Groundwater Contamination in Four US Locations

    Directory of Open Access Journals (Sweden)

    Andrew J. Leidner

    2014-01-01

    Full Text Available This paper provides a demonstration of propensity-score matching estimation methods to evaluate the effectiveness of health-risk communication efforts. This study develops a two-stage regression model to investigate household and respondent characteristics as they contribute to aversion behavior to reduce exposure to arsenic-contaminated groundwater. The aversion activity under study is a household-level point-of-use filtration device. Since the acquisition of arsenic contamination information and the engagement in an aversion activity may be codetermined, a two-stage propensity-score model is developed. In the first stage, the propensity for households to acquire arsenic contamination information is estimated. Then, the propensity scores are used to weight observations in a probit regression on the decision to avert the arsenic-related health risk. Of four potential sources of information, utility, media, friend, or others, information received from a friend appears to be the source of information most associated with aversion behavior. Other statistically significant covariates in the household’s decision to avert contamination include reported household income, the presence of children in household, and region-level indicator variables. These findings are primarily illustrative and demonstrate the usefulness of propensity-score methods to estimate health-risk communication effectiveness. They may also be suggestive of areas for future research.

  18. ARSENIC CONTAMINATION IN DRINKING WATER: AN ASSESSMENT FOR TURKEY

    Directory of Open Access Journals (Sweden)

    Meltem BİLİCİ ÇALIŞKAN

    2009-01-01

    Full Text Available Arsenic is one of the most abundant elements in the earth's crust and classified as a non-metal or a metalloid. Arsenic is toxic and carcinogen and in the environment occurs from both natural and anthropogenic sources. In the aqueous environment inorganic arsenic appears commonly in forms of arsenite (As(III and arsenate (As(V. pH, redox potential, and the presence of complexing ions such as ions of sulfur, iron, and calcium determine the arsenic valence and speciation. Because of the naturally occurring arsenic contamination in groundwater in many parts of the world many people have faced with risk of arsenic poisoning. In Turkey especially in the west regions, natural water sources contained much higher levels of arsenic than maximum contaminated level (MCL set (10 ?g/L were determined. In this study, arsenic problem and its reasons in Turkey were investigated. For this purpose, arsenic analyses were carried out and higher levels of arsenic than MCL was detected in some regions of Izmir. High levels of arsenic in these natural waters were considered to be associated with the dissolution of some minerals and rock formation.

  19. Arsenic Species in Drinking Water Wells in the USA with High Arsenic Concentrations

    Science.gov (United States)

    As part of the United States Environmental Protection Agency (USEPA) arsenic treatment demonstration program, 65 five well waters scattered across the US were speciated for As(III) and As(V). The speciation test data showed that most (60) well waters had one dominant species, but...

  20. Arsenic Species in Drinking Water Wells in the USA with High Arsenic Concentrations

    Science.gov (United States)

    As part of the United States Environmental Protection Agency (USEPA) arsenic treatment demonstration program, 65 five well waters scattered across the US were speciated for As(III) and As(V). The speciation test data showed that most (60) well waters had one dominant species, but...

  1. Current developments in toxicological research on arsenic.

    Science.gov (United States)

    Bolt, Hermann M

    2013-01-01

    There is a plethora of recent publications on all aspects relevant to the toxicology of arsenic (As). Over centuries exposures to arsenic continue to be a major public health problem in many countries. In particular, the occurrence of high As concentrations in groundwater of Southeast Asia receives now much attention. Therefore, arsenic is a high-priority matter for toxicological research. Key exposure to As are (traditional) medicines, combustion of As-rich coal, presence of As in groundwater, and pollution due to mining activities. As-induced cardiovascular disorders and carcinogenesis present themselves as a major research focus. The high priority of this issue is now recognized politically in a number of countries, research funds have been made available. Also experimental research on toxicokinetics and toxicodynamics and on modes of toxic action is moving very rapidly. The matter is of high regulatory concern, and effective preventive measures are required in a number of countries.

  2. Monsoonal influence on variation of hydrochemistry and isotopic signatures: Implications for associated arsenic release in groundwater

    Science.gov (United States)

    Majumder, Santanu; Datta, Saugata; Nath, Bibhash; Neidhardt, Harald; Sarkar, Simita; Roman-Ross, Gabriela; Berner, Zsolt; Hidalgo, Manuela; Chatterjee, Debankur; Chatterjee, Debashis

    2016-04-01

    The present study examines the groundwater and surface water geochemistry of two different geomorphic domains within the Chakdaha block, West Bengal, in an attempt to decipher potential influences of groundwater abstraction on the hydrochemical evolution of the aquifer, the effect of different water inputs (monsoon rain, irrigation and downward percolation from surface water impoundments) to the groundwater system and concomitant As release. A low-land flood plain and a natural levee have been selected for this purpose. Although the stable isotopic signatures of oxygen (δ18O) and hydrogen (δ2H) are largely controlled by local precipitation, the isotopic composition falls sub-parallel to the Global Meteoric Water Line (GMWL). The Cl/Br molar ratio indicates vertical recharge into the wells within the flood plain area, especially during the post-monsoon season, while influences of both evaporation and vertical mixing are visible within the natural levee wells. Increase in mean DOC concentrations (from 1.33 to 6.29 mg/L), from pre- to post-monsoon season, indicates possible inflow of organic carbon to the aquifer during the monsoonal recharge. Concomitant increase in AsT, Fe(II) and HCO3- highlights a possible initial episode of reductive dissolution of As-rich Fe-oxyhydroxides. The subsequent sharp increase in the mean As(III) proportions (by 223%), particularly in the flood plain samples during the post-monsoon season, which is accompanied by a slight increase in mean AsT (7%) may refer to anaerobic microbial degradation of DOC coupled with the reduction of As(V) to As(III) without triggering additional As release from the aquifer sediments.

  3. Arsenic contamination in surface drainage and groundwater in part of the southeast Asian tin belt, Nakhon Si Thammarat Province, southern Thailand

    Science.gov (United States)

    Williams, M.; Fordyce, F.; Paijitprapapon, A.; Charoenchaisri, P.

    1996-02-01

    The occurrence of human health problems resulting from arsenic contamination of domestic water supplies in Ron Phibun District, Nakhon Si Thammarat Province, southern Thailand was first recognized in 1987. The area has an extensive history of bedrock and alluvial mining, the waste from which is typically rich in arsenopyrite and related alteration products. In 1994 a collaborative study was instigated involving Thai and British government authorities to establish the distribution and geochemical form of As in surface drainage and aquifer systems in the affected area, the probable sources of As contamination, and the potential for problem alleviation. Hydrochemical analyses of surface- and groundwaters have confirmed the presence of dissolved As at concentrations exceeding WHO potable water guidelines by up to a factor of 500. Contamination of the shallow alluvial aquifer system is systematically more severe than the underlying carbonate-hosted aquifer. Deep boreholes may therefore provide the best available potable water source for the local population. The presence of up to 39% of total As as arsenite (H3AsO3) within the carbonate aquifer may, however, constitute a ‘hidden’ toxicological risk, not evident in the shallow groundwater (in which arsenate species account for > 95% of total As). Mineralogical investigations of As-rich tailings and flotation wastes were undertaken to evaluate their likely impact on water quality. The results indicate that although some flotation wastes contain up to 30% As, the rate of leaching is extremely low. Consequently the As loading of drainage emanating from such waste is below the subregional average. Analyses of the silty alluvium that covers much of the central sector of the study area have highlighted As concentrations of up to 5000 mg kg-1, probably carried by disseminated arsenopyrite. Following sulfide dissolution, the mobility of As in this material may be high (with resultant contamination of shallow groundwater) due

  4. The High Plains Aquifer, USA: Groundwater development and sustainability

    Science.gov (United States)

    Dennehy, K.F.; Litke, D.W.; McMahon, P.B.

    2002-01-01

    The High Plains Aquifer, located in the United States, is one of the largest freshwater aquifers in the world and is threatened by continued decline in water levels and deteriorating water quality. Understanding the physical and cultural features of this area is essential to assessing the factors that affect this groundwater resource. About 27% of the irrigated land in the United States overlies this aquifer, which yields about 30% of the nation's groundwater used for irrigation of crops including wheat, corn, sorghum, cotton and alfalfa. In addition, the aquifer provides drinking water to 82% of the 2.3 million people who live within the aquifer boundary. The High Plains Aquifer has been significantly impacted by human activities. Groundwater withdrawals from the aquifer exceed recharge in many areas, resulting in substantial declines in groundwater level. Residents once believed that the aquifer was an unlimited resource of high-quality water, but they now face the prospect that much of the water may be gone in the near future. Also, agricultural chemicals are affecting the groundwater quality. Increasing concentrations of nitrate and salinity can first impair the use of the water for public supply and then affect its suitability for irrigation. A variety of technical and institutional measures are currently being planned and implemented across the aquifer area in an attempt to sustain this groundwater resource for future generations. However, because groundwater withdrawals remain high and water quality impairments are becoming more commonplace, the sustainability of the High Plains Aquifer is uncertain.

  5. Can arsenic occurrence rates in bedrock aquifers be predicted?

    Science.gov (United States)

    Yang, Qiang; Jung, Hun Bok; Marvinney, Robert G.; Culbertson, Charles W.; Zheng, Yan

    2012-01-01

    A high percentage (31%) of groundwater samples from bedrock aquifers in the greater Augusta area, Maine was found to contain greater than 10 µg L−1 of arsenic. Elevated arsenic concentrations are associated with bedrock geology, and more frequently observed in samples with high pH, low dissolved oxygen, and low nitrate. These associations were quantitatively compared by statistical analysis. Stepwise logistic regression models using bedrock geology and/or water chemistry parameters are developed and tested with external data sets to explore the feasibility of predicting groundwater arsenic occurrence rates (the percentages of arsenic concentrations higher than 10 µg L−1) in bedrock aquifers. Despite the under-prediction of high arsenic occurrence rates, models including groundwater geochemistry parameters predict arsenic occurrence rates better than those with bedrock geology only. Such simple models with very few parameters can be applied to obtain a preliminary arsenic risk assessment in bedrock aquifers at local to intermediate scales at other localities with similar geology. PMID:22260208

  6. Arsenic in drinking water wells on the Bolivian high plain: Field monitoring and effect of salinity on removal efficiency of iron-oxides-containing filters.

    Science.gov (United States)

    Van Den Bergh, K; Du Laing, G; Montoya, Juan Carlos; De Deckere, E; Tack, F M G

    2010-11-01

    In the rural areas around Oruro (Bolivia), untreated groundwater is used directly as drinking water. This research aimed to evaluate the general drinking water quality, with focus on arsenic (As) concentrations, based on analysis of 67 samples from about 16 communities of the Oruro district. Subsequently a filter using Iron Oxide Coated Sand (IOCS) and a filter using a Composite Iron Matrix (CIM) were tested for their arsenic removal capacity using synthetic water mimicking real groundwater. Heavy metal concentrations in the sampled drinking water barely exceeded WHO guidelines. Arsenic concentrations reached values up to 964 μ g L⁻¹ and exceeded the current WHO provisional guideline value of 10 μ g L⁻¹ in more than 50% of the sampled wells. The WHO guideline of 250 mg L⁻¹ for chloride and sulphate was also exceeded in more than a third of the samples, indicating high salinity in the drinking waters. Synthetic drinking water could be treated effectively by the IOCS- and CIM-based filters reducing As to concentrations lower than 10 μ g L⁻¹. High levels of chloride and sulphate did not influence As removal efficiency. However, phosphate concentrations in the range from 4 to 24 mg L⁻¹ drastically decreased removal efficiency of the IOCS-based filter but had no effects on removal efficiency of the CIM-based filter. Results of this study can be used as a base for further testing and practical implementation of drinking water purification in the Oruro region.

  7. Sources and controls for the mobility of arsenic in oxidizing groundwaters from loess-type sediments in arid/semi-arid dry climates - evidence from the Chaco-Pampean plain (Argentina).

    Science.gov (United States)

    Nicolli, Hugo B; Bundschuh, Jochen; García, Jorge W; Falcón, Carlos M; Jean, Jiin-Shuh

    2010-11-01

    In oxidizing aquifers, arsenic (As) mobilization from sediments into groundwater is controlled by pH-dependent As desorption from and dissolution of mineral phases. If climate is dry, then the process of evaporative concentration contributes further to the total concentration of dissolved As. In this paper the principal As mobility controls under these conditions have been demonstrated for Salí River alluvial basin in NW Argentina (Tucumán Province; 7000 km(2)), which is representative for other basins or areas of the predominantly semi-arid Chaco-Pampean plain (1,000,000 km(2)) which is one of the world's largest regions affected by high As concentrations in groundwater. Detailed hydrogeochemical studies have been performed in the Salí River basin where 85 groundwater samples from shallow aquifers (42 samples), deep samples (26 samples) and artesian aquifers (17 samples) have been collected. Arsenic concentrations range from 11.4 to 1660 μg L(-1) leaving 100% of the investigated waters above the provisional WHO guideline value of 10 μg L(-1). A strong positive correlation among As, F, and V in shallow groundwaters was found. The correlations among those trace elements and U, B and Mo have less significance. High pH (up to 9.2) and high bicarbonate (HCO(3)) concentrations favour leaching from pyroclastic materials, including volcanic glass which is present to 20-25% in the loess-type aquifer sediments and yield higher trace element concentrations in groundwater from shallow aquifers compared to deep and artesian aquifers. The significant increase in minor and trace element concentrations and salinity in shallow aquifers is related to strong evaporation under semi-arid climatic conditions. Sorption of As and associated minor and trace elements (F, U, B, Mo and V) onto the surface of Fe-, Al- and Mn-oxides and oxi-hydroxides, restricts the mobilization of these elements into groundwater. Nevertheless, this does not hold in the case of the shallow unconfined

  8. Arsenic removal by perilla leaf biochar in aqueous solutions and groundwater: An integrated spectroscopic and microscopic examination.

    Science.gov (United States)

    Niazi, Nabeel Khan; Bibi, Irshad; Shahid, Muhammad; Ok, Yong Sik; Burton, Edward D; Wang, Hailong; Shaheen, Sabry M; Rinklebe, Jörg; Lüttge, Andreas

    2017-09-28

    In this study, we examined the removal of arsenite (As(III)) and arsenate (As(V)) by perilla leaf-derived biochars produced at 300 and 700 °C (referred as BC300 and BC700) in aqueous environments. Results revealed that the Langmuir isotherm model provided the best fit for As(III) and As(V) sorption, with the sorption affinity following the order: BC700-As(III) > BC700-As(V) > BC300-As(III) > BC300-As(V) (QL = 3.85-11.01 mg g(-1)). In general, As removal decreased (76-60%) with increasing pH from 7 to 10 except for the BC700-As(III) system, where notably higher As removal (88-90%) occurred at pH from 7 to 9. Surface functional moieties contributed to As sequestration by the biochars examined here. However, significantly higher surface area and aromaticity of BC700 favored a greater As removal compared to BC300, suggesting that surface complexation/precipitation dominated As removal by BC700. Arsenic K-edge X-ray absorption near edge structure (XANES) spectroscopy demonstrated that up to 64% of the added As(V) was reduced to As(III) in BC700- and BC300-As(V) sorption experiments, and in As(III) sorption experiments, partial oxidation of As(III) to As(V) occurred (37-39%). However, XANES spectroscopy was limited to precisely quantify As binding with sulfur species as As2S3-like phase. Both biochars efficiently removed As from natural As-contaminated groundwater (As: 23-190 μg L(-1); n = 12) despite in the presence of co-occurring anions (e.g., CO3(2-), PO4(3-), SO4(2-)) with the highest levels of As removal observed for BC700 (97-100%). Overall, this study highlights that perilla leaf biochars, notably BC700, possessed the greatest ability to remove As from solution and groundwater (drinking water). Significantly, the integrated spectroscopic techniques advanced our understanding to examine complex redox transformation of As(III)/As(V) with biochar, which are crucial to determine fate of As on biochar in aquatic environments. Copyright © 2017

  9. Evaluating the spatial distribution of quantitative risk and hazard level of arsenic exposure in groundwater, case study of Qorveh County, Kurdistan Iran.

    Science.gov (United States)

    Nasrabadi, Touraj; Bidabadi, Niloufar Shirani

    2013-01-01

    Regional distribution of quantitative risk and hazard levels due to arsenic poisoning in some parts of Iran's Kurdistan province is considered. To investigate the potential risk and hazard level regarding arsenic-contaminated drinking water and further carcinogenic and non-carcinogenic effects on villagers, thirteen wells in rural areas of Qorveh County were considered for evaluation of arsenic concentration in water. Sampling campaign was performed in August 2010 and arsenic concentration was measured via the Silver Diethyldithiocarbamate method. The highest and lowest arsenic concentration are reported in Guilaklu and Qezeljakand villages with 420 and 67 μg/L, respectively. None of thirteen water samples met the maximum contaminant level issued by USEPA and Institute of Standards and Industrial Research of Iran (10 ppb). The highest arsenic concentration and consequently risk and hazard levels belong to villages situated alongside the eastern frontiers of the county. Existence of volcanic activities within the upper Miocene and Pleistocene in this part of the study area may be addressed as the main geopogenic source of arsenic pollution. Quantitative risk values are varying from 1.49E-03 in Qezeljakand to 8.92E-03 in Guilaklu and may be interpreted as very high when compared by similar studies in Iran. Regarding non-carcinogenic effects, all thirteen water samples are considered hazardous while all calculated chronic daily intakes are greater than arsenic reference dose. Such drinking water source has the potential to impose adverse carcinogenic and non-carcinogenic effects on villagers. Accordingly, an urgent decision must be made to substitute the current drinking water source with a safer one.

  10. Evaluating the Spatial Distribution of Quantitative Risk and Hazard Level of Arsenic Exposure in Groundwater, case Study of Qorveh County, Kurdistan Iran

    Directory of Open Access Journals (Sweden)

    Touraj Nasrabadi

    2013-04-01

    Full Text Available Regional distribution of quantitative risk and hazard levels due to arsenic poisoning in some parts of Iran’s Kurdistan province is considered. To investigate the potential risk and hazard level regarding arsenic-contaminated drinking water and further carcinogenic and non-carcinogenic effects on villagers, thirteen wells in rural areas of Qorveh County were considered for evaluation of arsenic concentration in water. Sampling campaign was performed in August 2010 and arsenic concentration was measured via the Silver Diethyldithiocarbamate method. The highest and lowest arsenic concentration are reported in Guilaklu and Qezeljakand villages with 420 and 67 μg/L, respectively. None of thirteen water samples met the maximum contaminant level issued by USEPA and Institute of Standards and Industrial Research of Iran (10 ppb. The highest arsenic concentration and consequently risk and hazard levels belong to villages situated alongside the eastern frontiers of the county. Existence of volcanic activities within the upper Miocene and Pleistocene in this part of the study area may be addressed as the main geopogenic source of arsenic pollution. Quantitative risk values are varying from 1.49E-03 in Qezeljakand to 8.92E-03 in Guilaklu and may be interpreted as very high when compared by similar studies in Iran. Regarding non-carcinogenic effects, all thirteen water samples are considered hazardous while all calculated chronic daily intakes are greater than arsenic reference dose. Such drinking water source has the potential to impose adverse carcinogenic and non-carcinogenic effects on villagers. Accordingly, an urgent decision must be made to substitute the current drinking water source with a safer one.

  11. Arsenic in New Jersey Coastal Plain streams, sediments, and shallow groundwater: effects from different geologic sources and anthropogenic inputs on biogeochemical and physical mobilization processes

    Science.gov (United States)

    Barringer, Julia L.; Reilly, Pamela A.; Eberl, Dennis D.; Mumford, Adam C.; Benzel, William M.; Szabo, Zoltan; Shourds, Jennifer L.; Young, Lily Y.

    2013-01-01

    Arsenic (As) concentrations in New Jersey Coastal Plain streams generally exceed the State Surface Water Quality Standard (0.017 micrograms per liter (µg/L)), but concentrations seldom exceed 1 µg/L in filtered stream-water samples, regardless of geologic contributions or anthropogenic inputs. Nevertheless, As concentrations in unfiltered stream water indicate substantial variation because of particle inputs from soils and sediments with differing As contents, and because of discharges from groundwater of widely varying chemistry.

  12. Highly selective and rapid arsenic removal by metabolically engineered Escherichia coli cells expressing Fucus vesiculosus metallothionein.

    Science.gov (United States)

    Singh, Shailendra; Mulchandani, Ashok; Chen, Wilfred

    2008-05-01

    An arsenic-chelating metallothionein (fMT) from the arsenic-tolerant marine alga Fucus vesiculosus was expressed in Escherichia coli, resulting in 30- and 26-fold-higher As(III) and As(V) binding, respectively. Coexpression of the As(III)-specific transporter GlpF with fMT further improved arsenic accumulation and offered high selectivity toward As. Resting E. coli cells coexpressing fMT and GlpF completely removed trace amounts (35 ppb) of As(III) within 20 min, providing a promising technology for compliance with the As limit of 10 ppb newly recommended by the U.S. EPA.

  13. Highly Selective and Rapid Arsenic Removal by Metabolically Engineered Escherichia coli Cells Expressing Fucus vesiculosus Metallothionein▿

    Science.gov (United States)

    Singh, Shailendra; Mulchandani, Ashok; Chen, Wilfred

    2008-01-01

    An arsenic-chelating metallothionein (fMT) from the arsenic-tolerant marine alga Fucus vesiculosus was expressed in Escherichia coli, resulting in 30- and 26-fold-higher As(III) and As(V) binding, respectively. Coexpression of the As(III)-specific transporter GlpF with fMT further improved arsenic accumulation and offered high selectivity toward As. Resting E. coli cells coexpressing fMT and GlpF completely removed trace amounts (35 ppb) of As(III) within 20 min, providing a promising technology for compliance with the As limit of 10 ppb newly recommended by the U.S. EPA. PMID:18326684

  14. High exposure to inorganic arsenic by food: the need for risk reduction.

    Science.gov (United States)

    Gundert-Remy, Ursula; Damm, Georg; Foth, Heidi; Freyberger, Alexius; Gebel, Thomas; Golka, Klaus; Röhl, Claudia; Schupp, Thomas; Wollin, Klaus-Michael; Hengstler, Jan Georg

    2015-12-01

    Arsenic is a human carcinogen that occurs ubiquitously in soil and water. Based on epidemiological studies, a benchmark dose (lower/higher bound estimate) between 0.3 and 8 μg/kg bw/day was estimated to cause a 1 % increased risk of lung, skin and bladder cancer. A recently published study by EFSA on dietary exposure to inorganic arsenic in the European population reported 95th percentiles (lower bound min to upper bound max) for different age groups in the same range as the benchmark dose. For toddlers, a highly exposed group, the highest values ranged between 0.61 and 2.09 µg arsenic/kg bw/day. For all other age classes, the margin of exposure is also small. This scenario calls for regulatory action to reduce arsenic exposure. One priority measure should be to reduce arsenic in food categories that contribute most to exposure. In the EFSA study the food categories 'milk and dairy products,' 'drinking water' and 'food for infants' represent major sources of inorganic arsenic for infants and also rice is an important source. Long-term strategies are required to reduce inorganic arsenic in these food groups. The reduced consumption of rice and rice products which has been recommended may be helpful for a minority of individuals consuming unusually high amounts of rice. However, it is only of limited value for the general European population, because the food categories 'grain-based processed products (non rice-based)' or 'milk and dairy products' contribute more to the exposure with inorganic arsenic than the food category 'rice.' A balanced regulatory activity focusing on the most relevant food categories is required. In conclusion, exposure to inorganic arsenic represents a risk to the health of the European population, particularly to young children. Regulatory measures to reduce exposure are urgently required.

  15. Determination of multiple human arsenic metabolites employing high performance liquid chromatography inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Stice, Szabina; Liu, Guangliang; Matulis, Shannon; Boise, Lawrence H.; Cai, Yong

    2016-01-01

    During the metabolism of different arsenic-containing compounds in human, a variety of metabolites are produced with significantly varying toxicities. Currently available analytical methods can only detect a limited number of human metabolites in biological samples during one run due to their diverse characteristics. In addition, co-elution of species is often unnoticeable with most detection techniques leading to inaccurate metabolic profiles and assessment of toxicity. A high performance liquid chromatography inductively coupled mass spectrometry (HPLC-ICP-MS) method was developed that can identify thirteen common arsenic metabolites possibly present in human with special attention dedicated to thiolated or thiol conjugated arsenicals. The thirteen species included in this study are arsenite (AsIII), arsino-glutathione (As(GS)3), arsenate (AsV), monomethylarsonous acid (MMAIII), monomethylarsino-glutathione (MMAIII(GS)2), monomethylarsonic acid (MMAV), dimethylarsinous acid (DMAIII (from DMAIIII)), S-(dimethylarsinic)cysteine (DMAIII(Cys)), dimethylarsino-glutathione (DMAIII(GS)), dimethylarsinic acid (DMAV), dimethylmonothioarsinic acid (DMMTAV), dimethyldithioarsinic acid (DMDTAV), dimethylarsinothioyl glutathione (DMMTAV(GS)). The developed method was applied for the analysis of cancer cells that were incubated with Darinaparsin (DMAIII(GS)), a novel chemotherapeutic agent for refractory malignancies, and the arsenic metabolic profile obtained was compared to results using a previously developed method. This method provides a useful analytical tool which is much needed in unequivocally identifying the arsenicals formed during the metabolism of environmental arsenic exposure or therapeutic arsenic administration. PMID:26708625

  16. RESEARCH ON STEEL SLAG USED FOR REMEDIATION OF ARSENIC CONTAMINATED GROUNDWATER AS THE PRB FILLING%钢渣用作砷污染地下水修复PRB介质的研究

    Institute of Scientific and Technical Information of China (English)

    江愍格; 廖国权; 李华; 程芳琴; 史永林

    2012-01-01

    Based on analyzing the utilization characteristics and the contamination risk of steel slag, the remediation of arsenic contaminated groundwater with steel slag of PRB was simulated, and the influence of initial arsenic concentration, raw water flow rate to the performance of arsenic removal were studied, to explore the feasibility that the steel slag was used for remediation of the arsenic contaminated groundwater as the PRB filling. The results showed that the main elements of steel slag are Ca, Fe, Si, Mg, and Al, the main minerals as Ca2SiO4 and Ca3Mg(SiO4)2, because of the steel slag basicity and high mechanical strength also the porous structure, it can be used as a good filter performance and the adsorption material; The pH, heavy metals and fluorine content of the steel slag leaching solution were lower than China's hazardous waste leaching toxic identification standard, the risk of environmental pollution was relative small; In the same flow rate, arsenic removal of steel slag PRB in the initial arsenic 0.1 mg/L concentration was the biggest, when the flow rate was 0.5 mL/min, the influence of the initial concentration of arsenic removal rate was not obviously, the removal rate were above 96%; In the same initial concentration of arsenic, the arsenic removal of steel slag PRB decreased with increasing flow rate; Overall the steel slag PRB to the removal rate of arsenic with processing of increasing water drop, but processing water quantity to be 3 L, the lowest removal still can reach above 90%. Steel slag as PRB materials to handle high-arsenic groundwater was low cost, stable, reliable and high removal efficiency, and it was a broad prospect for the development and application of PRB materials.%在分析钢渣的资源利用特性与污染风险的基础上,模拟研究钢渣作为可渗透反应墙(PRB)介质对砷污染地下水的去除性能,分析初始砷浓度、原水流速等对除砷性能的影响,并对钢渣用作砷污染地下水原位修

  17. Treating chronic arsenic toxicity with high selenium lentil diets.

    Science.gov (United States)

    Sah, Shweta; Vandenberg, Albert; Smits, Judit

    2013-10-01

    Arsenic (As) toxicity causes serious health problems in humans, especially in the Indo-Gangetic plains and mountainous areas of China. Selenium (Se), an essential micronutrient is a potential mitigator of As toxicity due to its antioxidant and antagonistic properties. Selenium is seriously deficient in soils world-wide but is present at high, yet non-toxic levels in the great plains of North America. We evaluate the potential of dietary Se in counteracting chronic As toxicity in rats through serum biochemistry, blood glutathione levels, immunotoxicity (antibody response), liver peroxidative stress, thyroid response and As levels in tissues and excreta. To achieve this, we compare diets based on high-Se Saskatchewan (SK) lentils versus low-Se lentils from United States. Rats drank control (0ppm As) or As (40ppm As) water while consuming SK lentils (0.3ppm Se) or northwestern USA lentils (mitigate As toxicity in laboratory mammals, which we hope will translate into benefits for As exposed humans.

  18. Hydrogeochemical comparison and effects of overlapping redox zones on groundwater arsenic near the Western (Bhagirathi sub-basin, India) and Eastern (Meghna sub-basin, Bangladesh) margins of the Bengal Basin

    Science.gov (United States)

    Mukherjee, Abhijit; von Brömssen, Mattias; Scanlon, Bridget R.; Bhattacharya, Prosun; Fryar, Alan E.; Hasan, Md. Aziz; Ahmed, Kazi Matin; Chatterjee, Debashis; Jacks, Gunnar; Sracek, Ondra

    2008-07-01

    Although arsenic (As) contamination of groundwater in the Bengal Basin has received wide attention over the past decade, comparative studies of hydrogeochemistry in geologically different sub-basins within the basin have been lacking. Groundwater samples were collected from sub-basins in the western margin (River Bhagirathi sub-basin, Nadia, India; 90 samples) and eastern margin (River Meghna sub-basin; Brahmanbaria, Bangladesh; 35 samples) of the Bengal Basin. Groundwater in the western site (Nadia) has mostly Ca-HCO3 water while that in the eastern site (Brahmanbaria) is much more variable consisting of at least six different facies. The two sites show differences in major and minor solute trends indicating varying pathways of hydrogeochemical evolution However, both sites have similar reducing, postoxic environments (pe: + 5 to - 2) with high concentrations of dissolved organic carbon, indicating dominantly metal-reducing processes and similarity in As mobilization mechanism. The trends of various redox-sensitive solutes (e.g. As, CH4, Fe, Mn, NO3-, NH4+, SO42-) indicate overlapping redox zones, leading to partial redox equilibrium conditions where As, once liberated from source minerals, would tend to remain in solution because of the complex interplay among the electron acceptors.

  19. Arsenic removal from groundwater using low-cost carbon composite electrodes for capacitive deionization.

    Science.gov (United States)

    Lee, Ju-Young; Chaimongkalayon, Nantanee; Lim, Jinho; Ha, Heung Yong; Moon, Seung-Hyeon

    2016-01-01

    Affordable carbon composite electrodes were developed to treat low-concentrated groundwater using capacitive deionization (CDI). A carbon slurry prepared using activated carbon powder (ACP), poly(vinylidene fluoride), and N-methyl-2-pyrrolidone was employed as a casting solution to soak in a low-cost porous substrate. The surface morphology of the carbon composite electrodes was investigated using a video microscope and scanning electron microscopy. The capacitance and electrical conductivity of the carbon composite electrodes were then examined using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), respectively. According to the CV and EIS measurements, the capacitances and electrical conductivities of the carbon composite electrodes were in the range of 8.35-63.41 F g(-1) and 0.298-0.401 S cm(-1), respectively, depending on ACP contents. A CDI cell was assembled with the carbon composite electrodes instead of with electrodes and current collectors. The arsenate removal test included an investigation of the optimization of several important operating parameters, such as applied voltage and solution pH, and it achieved 98.8% removal efficiency using a 1 mg L(-1) arsenate solution at a voltage of 2 V and under a pH 9 condition.

  20. Removal of Arsenic from Drinking Water by Adsorption and Coagulation

    Science.gov (United States)

    Zhang, M.; Sugita, H.; Hara, J.; Takahashi, S.

    2013-12-01

    Removal of arsenic from drinking water has been an important issue worldwide, which has attracted greater attentions in recent years especially for supplying safe drinking water in developing countries. Although many kinds of treatment approaches that are available or applicable both in principle and practice, such as adsorption, coagulation, membrane filtration, ion exchange, biological process, electrocoagulation and so on, the first 2 approaches (i.e., adsorption and coagulation) are most promising due to the low-cost, high-efficiency, simplicity of treating systems, and thus can be practically used in developing countries. In this study, a literature survey on water quality in Bangladesh was performed to understand the ranges of arsenic concentration and pH of groundwater in Bangladesh. A series of tests were then organized and performed to investigate the effects of arsenic concentration, arsenic forms, pH, chemical compositions of the materials used for adsorption and coagulation, particle size distribution and treatment time on quality of treated water. The experimental results obtained in the study illustrated that both adsorption and coagulation can be used to effectively reduce the concentrations of either arsenic (V) or arsenic (III) from the contaminated water. Coagulation of arsenic with a magnesium-based material developed in this study can be very effective to remove arsenic, especially arsenic (V), from contaminated water with a concentration of 10 ppm to an undetectable level of 0.002 ppm by ICP analyses. Compared to arsenic (III), arsenic (V) is easier to be removed. The materials used for adsorption and coagulation in this study can remove arsenic (V) up to 9 mg/g and 6 mg/g, and arsenic (III) up to 4 mg/g and 3 mg/g, respectively, depending on test conditions and compositions of the materials being used. The control of pH during treatment can be a challenging technical issue for developing both adsorbent and coagulant. Keywords: Water Treatment

  1. Geochemical processes underlying a sharp contrast in groundwater arsenic concentrations in a village on the Red River delta, Vietnam

    Energy Technology Data Exchange (ETDEWEB)

    Eiche, Elisabeth [Institute of Mineralogy and Geochemistry, Universitaet Karlsruhe - TH, 76131 Karlsruhe (Germany)], E-mail: elisabeth.eiche@img.uni-karlsruhe.de; Neumann, Thomas [Institute of Mineralogy and Geochemistry, Universitaet Karlsruhe - TH, 76131 Karlsruhe (Germany); Berg, Michael [Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Duebendorf (Switzerland); Weinman, Beth [Earth and Environmental Sciences, Vanderbilt University, Nashville, TN 37240 (United States); Geen, Alexander van [Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964 (United States); Norra, Stefan; Berner, Zsolt [Institute of Mineralogy and Geochemistry, Universitaet Karlsruhe - TH, 76131 Karlsruhe (Germany); Pham Thi Kim Trang; Pham Hung Viet [Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, Hanoi (Viet Nam); Stueben, Doris [Institute of Mineralogy and Geochemistry, Universitaet Karlsruhe - TH, 76131 Karlsruhe (Germany)

    2008-11-15

    The spatial variability of As concentrations in aquifers of the Red River Delta, Vietnam, was studied in the vicinity of Hanoi. Two sites, only 700 m apart but with very different As concentrations in groundwater (site L: <10 {mu}g/L vs. site H: 170-600 {mu}g/L) in the 20-50 m depth range, were characterized with respect to sediment geochemistry and mineralogy as well as hydrochemistry. Sequential extractions of the sediment were carried out in order to understand why As is released to groundwater at one site and not the other. No major differences were observed in the bulk mineralogy and geochemistry of the sediment, with the exception of the redox state of Fe oxyhydroxides inferred from sediment colour and diffuse spectral reflectance. At site H most of the As in the sediment was adsorbed to grey sands of mixed Fe(II/III) valence whereas at site L As was more strongly bound to orange-brown Fe(III) oxides. Higher dissolved Fe and low dissolved S concentrations in groundwater at site H ({approx}14 mg Fe/L, <0.3 mg S/L) suggest more strongly reducing conditions compared to site L (1-2 mg Fe/L, <3.8 mg S/L). High concentrations of NH{sub 4}{sup +} ({approx}10 mg/L), HCO{sub 3}{sup -} (500 mg/L) and dissolved P (600 mg/L), in addition to elevated As at site H are consistent with a release coupled to microbially induced reductive dissolution of Fe oxyhydroxides. Other processes such as precipitation of siderite and vivianite, which are strongly supersaturated at site H, or the formation of amorphous Fe(II)/As(III) phases and Fe sulfides, may also influence the partitioning of As between groundwater and aquifer sands. The origin of the redox contrast between the two sites is presently unclear. Peat was observed at site L, but it was embedded within a thick clayey silt layer. At site H, instead, organic rich layers were only separated from the underlying aquifer by thin silt layers. Leaching of organic matter from this source could cause reducing conditions and therefore

  2. Arsenic species extraction of biological marine samples (Periwinkles, Littorina littorea) from a highly contaminated site.

    Science.gov (United States)

    Whaley-Martin, K J; Koch, I; Reimer, K J

    2012-01-15

    Arsenic is ubiquitous in the tissues of marine organisms and in uncontaminated environments it is dominantly present as the highly soluble and easily extractable non-toxic arsenical, arsenobetaine. However in contaminated environments, higher proportions of inorganic arsenic, which is much less soluble, are accumulated into the tissues of marine organisms, resulting in lower extraction efficiencies (defined as the percent extracted arsenic of the total arsenic). This study carried out a comparative analysis between three different two-step arsenic extraction methods based on Foster et al. [27] from highly contaminated tissue of the marine periwinkle, Littorina littorea. The first extraction step used 100% water, 1:1 methanol-water, or a 9:1 methanol-water as the extraction solvent and the second step consisted of a gently heated dilute nitric acid extraction. The optimized two step extraction method was 1:1 methanol-water extraction followed by a 2% HNO(3) extraction, based on maximum amounts of extracted species, including organoarsenic species.

  3. Protective Effects of B Vitamins and Antioxidants on the Risk of Arsenic-Related Skin Lesions in Bangladesh

    OpenAIRE

    2008-01-01

    Background An estimated 25–40 million of the 127 million people of Bangladesh have been exposed to high levels of naturally occurring arsenic from drinking groundwater. The mitigating effects of diet on arsenic-related premalignant skin lesions are largely unknown. Objectives The purpose of this study was to clarify the effects of the vitamin B group (thiamin, riboflavin, niacin, pyridoxine, and cobalamin) and antioxidants (vitamins A, C, and E) on arsenic-related skin lesions. Methods We per...

  4. Elevated naturally occurring arsenic in a semiarid oxidizing system, Southern High Plains aquifer, Texas, USA

    Science.gov (United States)

    Scanlon, B.R.; Nicot, J.-P.; Reedy, R.C.; Kurtzman, D.; Mukherjee, A.; Nordstrom, D.K.

    2009-01-01

    High groundwater As concentrations in oxidizing systems are generally associated with As adsorption onto hydrous metal (Al, Fe or Mn) oxides and mobilization with increased pH. The objective of this study was to evaluate the distribution, sources and mobilization mechanisms of As in the Southern High Plains (SHP) aquifer, Texas, relative to those in other semiarid, oxidizing systems. Elevated groundwater As levels are widespread in the southern part of the SHP (SHP-S) aquifer, with 47% of wells exceeding the current EPA maximum contaminant level (MCL) of 10 μg/L (range 0.3–164 μg/L), whereas As levels are much lower in the north (SHP-N: 9% ⩾ As MCL of 10 μg/L; range 0.2–43 μg/L). The sharp contrast in As levels between the north and south coincides with a change in total dissolved solids (TDS) from 395 mg/L (median north) to 885 mg/L (median south). Arsenic is present as arsenate (As V) in this oxidizing system and is correlated with groundwater TDS (Spearman’s ρ = 0.57). The most likely current source of As is sorbed As onto hydrous metal oxides based on correlations between As and other oxyanion-forming elements (V, ρ = 0.88; Se, ρ = 0.54; B, ρ = 0.51 and Mo, ρ = 0.46). This source is similar to that in other oxidizing systems and constitutes a secondary source; the most likely primary source being volcanic ashes in the SHP aquifer or original source rocks in the Rockies, based on co-occurrence of As and F (ρ = 0.56), oxyanion-forming elements and SiO2 (ρ = 0.41), which are found in volcanic ashes. High groundwater As concentrations in some semiarid oxidizing systems are related to high evaporation. Although correlation of As with TDS in the SHP aquifer may suggest evaporative concentration, unenriched stable isotopes (δ2H: −65 to −27; δ18O: −9.1 to −4.2) in the SHP aquifer do not support evaporation. High TDS in the SHP aquifer is most likely related to upward movement of saline water from the underlying

  5. Mechanism of Arsenic Sequestration in High-Iron Sediments

    Science.gov (United States)

    Root, R. A.; Campbell, K. M.; Hering, J. G.; O'Day, P. A.

    2005-12-01

    Naturally occurring elevated concentrations of arsenic in the runoff of the eastern Sierra Nevada and feed waters of the Los Angeles Aqueduct are remediated by the Los Angeles Department of Power and Water (LADPW) up stream of the Haiwee Reservoir (Olancha, CA). To reduce total arsenic in drinking water supplies, the LADPW adds ferric chloride and a cationic polymer coagulant to the aqueduct. The treatment precipitates as an amorphous iron oxide, spectrally similar to 6-line ferrihydrite, that adsorbs and sequesters arsenic as arsenate. As the channeled flow enters North Haiwee Reservoir, the As(V)-enriched iron floc settles as sediments in the inlet channel. Buried As(V) is reduced to As(III) near the sediment-water interface (0-10cm), and only As(III) is observed at depths below the steep (1-2cm) near-surface redox gradient. Sediment samples from 30-cm push cores were collected from the edge of the reservoir along the inlet channel in tandem with in situ porewater measurements using an inert polyacrylamide gel probe sampler. Sediments were analyzed to characterize the redox gradient, host mineralogy, and variation in bulk elemental composition with depth. X-ray absorption spectroscopy (XAS) was used to determine the depth of the microbially driven redox boundary where As (V) is reduced to As (III) and to investigate the molecular bonding of arsenic adsorbed to iron hydroxide surfaces. Specific and characteristic iron and arsenic phases were isolated by sequential extraction; extracted and bulk concentrations were determined by ICP-MS. Splits of specific extraction steps were analyzed by synchrotron EXAFS and XRD to determine the identity of separated phases. The primary mineralogy of sediments along the inlet channel is detrital quartz, plagioclase feldspar, and phyllosilicates weathered from the Sierra Nevada granitic batholith. Notably, crystalline magnetite, hematite, and goethite, phases that would indicate transformation of hydrous iron phases to more stable

  6. Simulating Groundwater Recharge Across the Southern High Plains

    Science.gov (United States)

    Smidt, S. J.; Haacker, E. M.; Kendall, A. D.; Hyndman, D. W.

    2015-12-01

    Quantifying recharge and water availability across the Southern High Plains is a difficult, but necessary, challenge for future groundwater and agricultural projections. Overland flow is not common due to limited precipitation, dry soils, and high evapotranspiration. The majority of runoff is temporarily stored in playa lakes, leading to the bulk of recharge across the region occurring in localized infiltration zones beneath these lakes. Despite the importance of regional recharge estimates, limited information exists that integrates complex characteristics of the land, climate, and hydrology in order to quantify recharge across the entire Southern High Plains aquifer. This study applies the Landscape Hydrology Model (LHM) to capture these characteristics and simulate surface water flow and groundwater recharge. This model simulates the complete water cycle across large regions, including irrigation estimates, establishing a framework to estimate recharge and groundwater availability in the Southern High Plains region. Results from this study can be used to predict the likely impacts of climate change and improve water management strategies.

  7. Assessment of toxic metals in groundwater and saliva in an arsenic affected area of West Bengal, India: A pilot scale study.

    Science.gov (United States)

    Bhowmick, Subhamoy; Kundu, Amit Kumar; Adhikari, Jishnu; Chatterjee, Debankur; Iglesias, Monica; Nriagu, Jerome; Guha Mazumder, Debendra Nath; Shomar, Basem; Chatterjee, Debashis

    2015-10-01

    Communities in many parts of the world are unintentionally exposed to arsenic (As) and other toxic metals through ingestion of local drinking water and foods. The concentrations of individual toxic metals often exceed their guidelines in drinking water but the health risks associated with such multiple-metal exposures have yet to receive much attention. This study examines the co-occurrence of toxic metals in groundwater samples collected from As-rich areas of Nadia district, West Bengal, India. Arsenic in groundwater (range: 12-1064 µg L(-1); mean ± S.D: 329±294 µg L(-1)) was the most important contaminant with concentrations well above the WHO guideline of 10 µg L(-1). Another important toxic metal in the study area was manganese (Mn) with average concentration of 202±153 µg L(-1), range of 18-604 µg L(-1). The average concentrations (µg L(-1)) of other elements in groundwater were: Cr (5.6±5.9), Mo (3.5±2.1), Ni (8.3±8.7), Pb (2.9±1.3), Ba (119±43), Zn (56±40), Se (0.60±0.33), U (0.50±0.74). Saliva collected from the male participants of the area had mean concentrations of 6.3±7.0 µg As L(-1) (0.70-29 µg L(-1)), 5.4±5.5 µg Mn L(-1) (0.69-22 µg L(-1)), 2.6±3.1 µg Ni L(-1) (0.15-13 µg L(-1)), 0.78±1.0µg Cr L(-1) (metals beside As must be monitored in drinking water before implementation of any policies to provide safe water to the affected communities. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Hydrologically Controlled Arsenic Release in Deltaic Wetlands and Coastal Riparian Zones

    Science.gov (United States)

    Stuckey, J.; LeMonte, J. J.; Yu, X.; Schaefer, M.; Kocar, B. D.; Benner, S. G.; Rinklebe, J.; Tappero, R.; Michael, H. A.; Fendorf, S. E.; Sparks, D. L.

    2016-12-01

    Wetland and riparian zone hydrology exerts critical controls on the biogeochemical cycling of metal contaminants including arsenic. The role of wetlands in driving geogenic arsenic release to groundwater has been debated in the deltas of South and Southeast Asia where the largest impacted human population resides. In addition, groundwater in coastal areas worldwide, such as those in South and Southeast Asia and the Mid-Atlantic of the U.S., is at risk to largely unexplored biogeochemical and hydrologic impacts of projected sea level rise. First, we present data from fresh-sediment incubations, in situ model sediment incubations and a controlled field experiment with manipulated wetland hydrology and organic carbon inputs in the minimally disturbed upper Mekong Delta. Here we show that arsenic release is limited to near-surface sediments of permanently saturated wetlands where both organic carbon and arsenic-bearing solids are sufficiently reactive for microbial oxidation of organic carbon and reduction of arsenic-bearing iron oxides. In contrast, within the deeper aquifer or seasonally saturated sediments, reductive dissolution of iron oxides is observed only when either more reactive exogenous forms of iron oxides or organic carbon are added, revealing a potential thermodynamic restriction to microbial metabolism. Second, in order to assess the potential impacts of sea level rise on arsenic release to groundwater, we determined the changes in arsenic speciation and partitioning in sediment collected from an anthropogenically contaminated coastal riparian zone under controlled Eh regimes in both seawater and freshwater systems. Here we show greater arsenic release under anoxic/suboxic conditions in the freshwater system than in the seawater system, potentially due to high salinity induced microbial inhibition. Collectively, our work shows that shifting hydrologic conditions in deltaic wetlands and tidally influenced zones impacts the extent of arsenic release to

  9. Arsenic in tree rings at a highly contaminated site.

    Science.gov (United States)

    Cheng, Zhongqi; Buckley, Brendan M; Katz, Beth; Wright, William; Bailey, Richard; Smith, Kevin T; Li, Jingbo; Curtis, Ashley; Geen, Alexander van

    2007-04-15

    Arsenic concentrations were measured in annual rings, pith, bark, and leaves of five tree species (four genera) from a site highly contaminated with As in Vineland, New Jersey, and two nearby uncontaminated areas. The highest As concentrations were found in bark (0.68+/-0.89 mg/kg, n=16) and leaves (1.9+/-1.8 mg/kg, n=4) from the contaminated area. Tree-ring As levels from the contaminated area (0.28+/-0.15 mg/kg, n=32) were low but still considerably higher than those from the control areas (0.06+/-0.06 mg/kg, n=30). There is a generally positive relationship between soil and tree-ring As levels. The overall low uptake of As by trees contrasts with that of P, a chemical analog for As(V) in aerated soils. Much higher P concentration in sapwood than in heartwood indicates that P is exported into more recently formed wood during the conversion from sapwood to heartwood; this again is drastically different than the behavior of As which is present in sapwood and heartwood at comparable levels. Variable sapwood As concentrations observed in detailed radial profiles of tree-ring chemistry of a pine and an oak from the contaminated site suggest that As is most likely transported among multiple rings within the sapwood. Therefore, tree species for which sapwood is thin (e.g., oak as in this study) should be preferred for reconstructing the history of contamination of a site. Due to the possibility of lateral translocation between growth rings, further studies are necessary to understand within-tree As transport and storage before dendrochemistry can be confidently accepted for such applications.

  10. Metagenomic analysis revealed highly diverse microbial arsenic metabolism genes in paddy soils with low-arsenic contents.

    Science.gov (United States)

    Xiao, Ke-Qing; Li, Li-Guan; Ma, Li-Ping; Zhang, Si-Yu; Bao, Peng; Zhang, Tong; Zhu, Yong-Guan

    2016-04-01

    Microbe-mediated arsenic (As) metabolism plays a critical role in global As cycle, and As metabolism involves different types of genes encoding proteins facilitating its biotransformation and transportation processes. Here, we used metagenomic analysis based on high-throughput sequencing and constructed As metabolism protein databases to analyze As metabolism genes in five paddy soils with low-As contents. The results showed that highly diverse As metabolism genes were present in these paddy soils, with varied abundances and distribution for different types and subtypes of these genes. Arsenate reduction genes (ars) dominated in all soil samples, and significant correlation existed between the abundance of arr (arsenate respiration), aio (arsenite oxidation), and arsM (arsenite methylation) genes, indicating the co-existence and close-relation of different As resistance systems of microbes in wetland environments similar to these paddy soils after long-term evolution. Among all soil parameters, pH was an important factor controlling the distribution of As metabolism gene in five paddy soils (p = 0.018). To the best of our knowledge, this is the first study using high-throughput sequencing and metagenomics approach in characterizing As metabolism genes in the five paddy soil, showing their great potential in As biotransformation, and therefore in mitigating arsenic risk to humans.

  11. The character of organic carbon in recharge water and arsenic mobilization in Bangladesh aquifers

    Science.gov (United States)

    Pracht, L. E.; Fussell, A. H.; Polizzotto, M.; Badruzzaman, A. M.; Ali, M. A.; Neumann, R. B.

    2012-12-01

    In Bangladesh, arsenic-contaminated groundwater, used for both drinking and irrigation supplies, negatively affects the health of millions of people. Past work at our site in Munshiganj suggests that current patterns of arsenic concentration in the aquifer are related to groundwater flow and recharge chemistry. Constructed ponds and groundwater-irrigated rice fields serve as the primary aquifer recharge sources, with pond recharge evolving into high-arsenic groundwater and rice field recharge evolving into low-arsenic groundwater. The composition of these water types vary in concentrations and character of dissolved organic carbon, a presumed key component in the mechanism of arsenic release from sediments. Here we present results from an experiment-based laboratory study that directly tests the role of organic carbon character and bioavailability on arsenic mobilization. Incubation experiments using sediment samples collected from Bangladesh and waters with different carbon sources (e.g., pond and rice field recharge water and artificial water with model carbon compounds) were conducted to show the phase transformations carbon undergoes during arsenic mobilization processes, to isolate the carbon components and characteristics most responsible for mobilization reactions, and to investigate the importance of secondary chemical constituents for completion of these physiochemical reactions. Water, gas, and sediment samples collected from the incubations were analyzed for nutrient, metal, anion, and carbon concentrations, as well as carbon character. The results clarify the chemical components most critical in arsenic mobilization and provide insight into the in situ chemical reactions occurring in the aquifer. Moreover, this better chemical understanding helps elucidate the potential impact of altered recharge patterns and recharge chemistry on arsenic concentrations of Bangladeshi groundwater supplies.

  12. Metabolism of inorganic arsenic in children with chronic high arsenic exposure in northern Argentina.

    Science.gov (United States)

    Concha, G; Nermell, B; Vahter, M V

    1998-01-01

    This study concerns the metabolism of inorganic arsenic (As) in children in three villages in northern Argentina: San Antonio de los Cobres and Taco Pozo, each with about 200 microg As/l in the drinking water, and Rosario de Lerma, with 0.65 microg As/l. Findings show that the concentrations of As in the blood and urine of the children in the two As-rich villages were on average 9 and 380 microg/l, respectively, the highest ever recorded for children. The concentrations were about 10 and 30 times higher for blood and urine, respectively, than in Rosario de Lerma. Total As in urine was only slightly higher than the sum of metabolites of inorganic As (U-Asmet), i.e., inorganic As, methylarsonic acid (MMA), and dimethylarsinic acid (DMA); this shows that inorganic As was the main form of As ingested. In contrast to previous studies on urinary metabolites of inorganic As in various population groups, the children and women in the present study excreted very little MMA. Thus, there seems to be a polymorphism for the enzymes (methyltransferases) involved in the methylation of As. Interestingly, the children had a significantly higher percentage of inorganic As in urine than the women, about 50% versus 32%. Also, the percentage of inorganic As in the children is considerably higher than in previous studies on children (about 13% in the two studies available) and adults (about 15-25%) in other population groups. This may indicate that children are more sensitive to As-induced toxicity than adults, as the methylated metabolites bind less to tissue constituents than inorganic As. In the children, the percentage inorganic arsenic in urine decreased, and the percentage of DMA increased with increasing U-Asmet, indicating an induction of As methylation with increasing exposure. Images Figure 1 Figure 2 Figure 3 PMID:9618352

  13. Understanding arsenic mobilization using reactive transport modeling of groundwater hydrochemistry in the Datong basin study plot, China.

    Science.gov (United States)

    Mapoma, Harold Wilson Tumwitike; Xie, Xianjun; Pi, Kunfu; Liu, Yaqing; Zhu, Yapeng

    2016-03-01

    This paper discusses the reactive transport and evolution of arsenic along a selected flow path in a study plot within the central part of Datong basin. The simulation used the TOUGHREACT code. The spatial and temporal trends in hydrochemistry and mineral volume fraction along a flow path were observed. Furthermore, initial simulation of major ions and pH fits closely to the measured data. The study shows that equilibrium conditions may be attained at different stress periods for each parameter simulated. It is noted that the variations in ionic chemistry have a greater impact on arsenic distribution while reducing conditions drive the mobilization of arsenic. The study concluded that the reduction of Fe(iii) and As(v) and probably SO4/HS cycling are significant factors affecting localized mobilization of arsenic. Besides cation exchange and water-rock interaction, incongruent dissolution of silicates is also a significant control mechanism of general chemistry of the Datong basin aquifer.

  14. Arsenic contamination in sesame and possible mitigation through organic interventions in the lower Gangetic Plain of West Bengal, India.

    Science.gov (United States)

    Sinha, Bishwajit; Bhattacharyya, Kallol; Giri, Pradip K; Sarkar, Supradip

    2011-12-01

    The widespread geogenic arsenic contamination of groundwater in the Gangetic Delta of West Bengal, leading to toxicities through the food chain-principally through irrigated rice-drew due attention from researchers. Oilseeds such as sesame might be a remunerative alternative to rice and can be grown with small quantities of contaminated groundwater. The present study was conducted to explore the efficiency of organic matter in reducing arsenic accumulation in sesame. Accumulation of total arsenic in sesame seed and available arsenic in post-harvest soils varied from 0.08 to 0.58 mg kg(-1) and from 3.87 to 8.89 kg ha(-1) , respectively. The organic manures added as soil amendment significantly reduced the accumulation (concentration) of arsenic in sesame seed to a maximum extent of 65.5% (vermicompost), 50% (phosphocompost), 42% (mustard cake) and 40% (farmyard manure (FYM)) compared with the control counterpart. The risk associated with dietary exposure to arsenic-contaminated sesame oil reached a value of 15.55% of provisional tolerable weekly intake for arsenic at the maximum accumulation of arsenic in sesame oil. Substantial accumulation of arsenic in the soil-plant system was found. Risks of exposure to arsenic-contaminated oil remained considerably high. Irrigation through surface water and organic amendments both significantly reduced arsenic accumulation in sesame. Copyright © 2011 Society of Chemical Industry.

  15. Assessment of processes controlling the regional distribution of fluoride and arsenic in groundwater of the Pampeano Aquifer in the Del Azul Creek basin (Argentina)

    Science.gov (United States)

    Zabala, M. E.; Manzano, M.; Vives, L.

    2016-10-01

    Groundwater in the upper 50 m of the Pampeano Aquifer in the Del Azul Creek basin (Argentina) has F and As contents above the WHO safe drinking levels. This basin is situated to the SE of the Chaco-Pampean plain, in Buenos Aires Province. The Pampeano Aquifer is a major water source for all uses. The aim of the study is to assess the primary processes controlling the regional distribution of F and As in the most exploited part of the aquifer. The study involved sampling for chemical and isotopic analyses, interpretation of data with different methods (diagrams, bivariate analyses, mineral saturation states, Principal Component Analysis) and deduction of leading processes. Information about aquifer mineralogy and hydrogeochemical processes involved in F and As solubilization in the aquifer has been taken from previous works of the same and other authors. Groundwater salinity increases to the NE, in the direction of the regional groundwater flow. Chemical types evolve from Ca/Mg-HCO3 in the upper part of the basin, to Na-HCO3 in the middle part and to Na-ClSO4 and Na-Cl in the lower part. The regional distribution of F is controlled by hydrogeochemical processes. The distribution of As is controlled by two types of processes dominating in different areas: hydrogeochemical controls prevail in the low to moderately mineralized groundwater of the middle and lower parts of the basin; hydrogeological controls lead to the NE of the lower basin and beyond it. In the last zone there are abundant lagoons and seasonal flooding is frequent, making evapoconcentration an important process for groundwater mineralization. The main hydrogeochemical processes involved in both F and As distribution are cation exchange, with Na release and Ca uptake, carbonate dissolution and pH increase. Arsenic release induced by redox processes may play to the NE, but its results would be masked by the effect of evaporation.

  16. Arsenic contamination of drinking water in Ireland: A spatial analysis of occurrence and potential risk.

    Science.gov (United States)

    McGrory, Ellen R; Brown, Colin; Bargary, Norma; Williams, Natalya Hunter; Mannix, Anthony; Zhang, Chaosheng; Henry, Tiernan; Daly, Eve; Nicholas, Sarah; Petrunic, Barbara M; Lee, Monica; Morrison, Liam

    2017-02-01

    The presence of arsenic in groundwater has become a global concern due to the health risks from drinking water with elevated concentrations. The Water Framework Directive (WFD) of the European Union calls for drinking water risk assessment for member states. The present study amalgamates readily available national and sub-national scale datasets on arsenic in groundwater in the Republic of Ireland. However, due to the presence of high levels of left censoring (i.e. arsenic values below an analytical detection limit) and changes in detection limits over time, the application of conventional statistical methods would inhibit the generation of meaningful results. In order to handle these issues several arsenic databases were integrated and the data modelled using statistical methods appropriate for non-detect data. In addition, geostatistical methods were used to assess principal risk components of elevated arsenic related to lithology, aquifer type and groundwater vulnerability. Geographic statistical methods were used to overcome some of the geographical limitations of the Irish Environmental Protection Agency (EPA) sample database. Nearest-neighbour inverse distance weighting (IDW) and local indicator of spatial association (LISA) methods were used to estimate risk in non-sampled areas. Significant differences were also noted between different aquifer lithologies, indicating that Rhyolite, Sandstone and Shale (Greywackes), and Impure Limestone potentially presented a greater risk of elevated arsenic in groundwaters. Significant differences also occurred among aquifer types with poorly productive aquifers, locally important fractured bedrock aquifers and regionally important fissured bedrock aquifers presenting the highest potential risk of elevated arsenic. No significant differences were detected among different groundwater vulnerability groups as defined by the Geological Survey of Ireland. This research will assist management and future policy directions of

  17. Contrasting influence of geology on E. coli and arsenic in aquifers of Bangladesh.

    Science.gov (United States)

    Leber, Jessica; Rahman, M Moshiur; Ahmed, Kazi M; Mailloux, Brian; van Geen, Alexander

    2011-01-01

    Arsenic in groundwater has been a concern in South and Southeast Asia for more than a decade. We explore here the possibility that hydrogeologic factors recently shown to influence the distribution of arsenic might also affect the level of contamination of shallow (Bangladesh were surveyed during the wet and dry seasons, along with 55 deeper wells in neighboring villages. One of the two villages is located in a particularly sandy environment where recharge is rapid and shallow wells contain little arsenic. Shallow aquifers in the other village are capped with an impermeable clay layer, recharge is an order of magnitude slower, and arsenic levels are high. The fecal indicator E. coli was detected in 43% of shallow wells, compared with 12% of deeper wells. More shallow wells contained E. coli during the wet season (61%) than during the dry season (9%). In the wet season, a higher proportion of shallow wells in the village with low arsenic levels (72%) contained E. coli compared with the village having high arsenic levels (43%). Differences in arsenic and E. coli distributions between the two sites are likely due to the differences in permeability of near-surface sediments although differences in average well-depth between the two villages (9 ± 4 vs. 15 ± 3 m) may play a role as well. Hydrogeologic conditions that favor high levels of fecal contamination but low levels of arsenic in shallow groundwater should be taken into account during arsenic mitigation throughout South and Southeast Asia.

  18. Heavy metals, arsenic, and pesticide contamination in an area with high incidence of chronic kidney disease of non-traditional causes in El Salvador

    Science.gov (United States)

    Lopez, D. A.; Ribó, A.; Quinteros, E.; Mejia, R.; Jovel, R.; VanDervort, D.; Orantes, C. M.

    2013-12-01

    Chronic kidney disease of non-traditional causes is epidemic in Central America, Southern Mexico and other regions of the world such as Sri Lanka, where the origin of the illness is attributed to exposure to agrochemicals and arsenic in soils and groundwater. In Central America, several causes have been suggested for this illness including: high ambient temperatures and chronic dehydration, and toxic effects of agrochemicals. Previous research using step-wise multivariate regression in El Salvador found statistically significant correlation between the spatial distribution of the number of sick people per thousand inhabitants and the percent area cultivated with sugar cane, cotton, and beans, and maximum ambient temperature, with sugar cane cultivation as the most significant factor. This study aims to investigate the possible effects of agricultural activities in the occurrence of this illness looking at heavy metal, arsenic and pesticide contamination in soil, water and sediments of a community located in Bajo Lempa region (Ciudad Romero, El Salvador) and heavily affected by this illness. The Bajo Lempa region is close to Lempa River delta, in the Pacific coast. Ground and surface water, sediment and soil samples were collected in the village where the patients live and in the agricultural areas where they work. With respect to the heavy metals, lead and cadmium where detected in the soils but below the standards for cultivated soils, however, they were not detected in the majority of surface and groundwater. Of the inorganic contaminants, arsenic was present in most soil, sediments, and water samples with some concentrations considerable higher than the standards for cultivated lands and drinking water. Statistically different concentrations in soils were found for the village soils and the cultivated soils, with arsenic higher in the cultivated soils. For the pesticides, results show a significant pollution of soil and groundwater of organochlorine pesticides

  19. A novel method to remove arsenic from water

    Science.gov (United States)

    McDonald, Kyle J.

    occurring arsenic in water from West Bengal, India. This is, to our knowledge, the first time CuO nanoparticles have been used to treat groundwater from West Bengal which has been recognized for greater than two decades as some of the most significantly arsenic affected regions in the world. Our results show that CuO nanoparticles can remove arsenic from water under a wide range of geochemistries without pretreatments. In addition, CuO nanoparticles can be regenerated by desorbing arsenic using NaOH and are effective in removing arsenic following the regeneration. Further, field demonstration of a point-of-use flow through adsorption column was successful in removing arsenic from a variety of waters that contain naturally high concentrations of arsenic. This research suggests that CuO nanoparticles show promise as a viable treatment technology for removing arsenic from water.

  20. Toxic elements in soil and groundwater: short-time study on electrokinetic removal of arsenic in the presence of other ions.

    Science.gov (United States)

    Leszczynska, Danuta; Ahmad, Hafiz

    2006-06-01

    The electrokinetic technique is an emerging technology presently tested in situ to remove dissolved heavy metals from contaminated groundwater. There is a growing interest for using this system to cleanse clayey soil contaminated by toxic metallic ions. Currently, there are very few available non-destructive treatment methods that could be successfully applied in situ on low permeable type of soil matrix. The main objective of presented study was to validate and possibly enhance the overall efficiency of decontamination by the electrokinetic technique of the low permeable soil polluted by the arsenic in combination with chromium and copper ions. The chosen mixture of ions was imitating leak of pesticide well known as chromate copper arsenate (CCA). The chosen technique is showing a big promise to be used in the future as a portable, easy to install and run on sites with spills or leaks hard to reach otherwise; such as in the dense populated and urbanized areas. Laboratory electrokinetic experiments were designed to understand and possibly manipulate main mechanisms involved during forced migration of ions. All tests were conducted on artificially contaminated kaolinite (low permeable clay soil). Electrokinetic migration was inducted by the low voltage dc current applied through soil column. Series of experiments were designed to assess the efficiency of arsenic-chromium-copper remediation by applying (1) only dc current; and (2) by altering the soil environment. Obtained results showed that arsenic could be successfully removed from the soil in one day (25 hours) span. It was significant time reduction, very important during emergency response. Mass recovered at the end of each test depended on initial condition of soil and type of flushing solution. The best results were obtained, when soil was flushed with either NaOH or NaOCl (total removal efficiency 74.4% and 78.1%, respectively). Direct analysis of remained arsenic in soil after these tests confirmed

  1. Toxic Elements in Soil and Groundwater: Short-Time Study on Electrokinetic Removal of Arsenic in the Presence of other Ions

    Directory of Open Access Journals (Sweden)

    Hafiz Ahmad

    2006-06-01

    Full Text Available The electrokinetic technique is an emerging technology presently tested in situ to remove dissolved heavy metals from contaminated groundwater. There is a growing interest for using this system to cleanse clayey soil contaminated by toxic metallic ions. Currently, there are very few available non-destructive treatment methods that could be successfully applied in situ on low permeable type of soil matrix. The main objective of presented study was to validate and possibly enhance the overall efficiency of decontamination by the electrokinetic technique of the low permeable soil polluted by the arsenic in combination with chromium and copper ions. The chosen mixture of ions was imitating leak of pesticide well known as chromate copper arsenate (CCA. The chosen technique is showing a big promise to be used in the future as a portable, easy to install and run on sites with spills or leaks hard to reach otherwise; such as in the dense populated and urbanized areas. Laboratory electrokinetic experiments were designed to understand and possibly manipulate main mechanisms involved during forced migration of ions. All tests were conducted on artificially contaminated kaolinite (low permeable clay soil. Electrokinetic migration was inducted by the low voltage dc current applied through soil column. Series of experiments were designed to assess the efficiency of arsenic-chromium-copper remediation by applying (1 only dc current; and (2 by altering the soil environment. Obtained results showed that arsenic could be successfully removed from the soil in one day (25 hours span. It was significant time reduction, very important during emergency response. Mass recovered at the end of each test depended on initial condition of soil and type of flushing solution. The best results were obtained, when soil was flushed with either NaOH or NaOCl (total removal efficiency 74.4% and 78.1%, respectively. Direct analysis of remained arsenic in soil after these tests

  2. Targeting Safer Aquifer At A Highly Arsenic Contaminated Community; South-Western Bangladesh

    Science.gov (United States)

    Tauhid-Ur-Rahman, Md.

    2010-05-01

    The depositional pattern, geochemistry and mineralogy of the Arsenic (As) contaminated sediments along with the chemistry of groundwaters extracted from the Holocene deposit of an As hotspot, Kalaroa, Southwestern Bangladesh have been investigated in this study. These were done to elucidate a unified view that could explain the accumulation and distribution of As on the sediment surface and its subsequent release into the groundwater. Such view of As distribution mainly helped to find out eventually the possible existence of any safer aquifer that could provide adequate potable water to that targeted community. Two key geochemical parameters, the reaction rate Kr and the partition coefficient, Kd were found to be very promising in explaining the As release mechanism. Showing the realistic natural biotite dissolution process, the in-situ Kr that was derived by applying inverse mass balance model (2.72 × 10-16 /sec), was found to be slower by only three orders of magnitude than that was determined with the laboratory study (3.19×10-13 /sec). A parametric predictor equation, that can calculate the partition coefficient Kd based on the aquifer sediment's minerals such as Fe and Al contents along with pore-water pH was developed in this study. Another Kd model based on the diffuse double layer surface complexation theory has also been developed to compare the appropriateness of the parametric Kd model. These two models were compared with the in-situ based field Kd data and were found in a good agreement. Integrating those two essential geochemical parameters (Kd and Kr), a 1D-Finite Difference numerical model was applied to observe and evaluate the As pollution scenario for the studied Holocene aquifer. The simulation showed very promising results introducing the idea that the deeper aquifer's groundwaters would be remained safe against being contaminated with high As in future, due to the presence of a number of encouraging factors. The most significant among such

  3. On the arsenic source mobilisation and its natural enrichment in the sediments of a high mountain cirque in the Pyrenees.

    Science.gov (United States)

    Zaharescu, Dragos George; Hooda, Peter S; Fernandez, Javier; Soler, Antonio Palanca; Burghelea, Carmen Ionela

    2009-11-01

    Recently arsenic contamination and its environmental and human health problems have been raising concerns worldwide. The occurrence of natural high levels of arsenic contamination has generally been reported for low altitude environments. Here we report a study conducted to assess the extent of arsenic mobilisation/transportation from previously identified arsenic source areas in a high altitude cirque of the Pyrenees as well as the potential contribution of As by snow. The concentration of arsenic in sediments of several tributaries was enriched up to about ten folds due to mobilisation of arsenic from the source areas within the catchment. The highest arsenic enrichments were found in an area dominated by quartzite and slate formation in the southern side of the basin, and it generally diminished towards the major lake downstream, possible due to mixing with sediments from non-source areas. At these sites arsenic exceeded the hazard quotient (HQ) limits for the protection of aquatic life. The potential hazard of the As-enriched sediments may be further enhanced outside the catchment as samples collected downstream the cirque have also shown arsenic concentration exceeding HQ unity. The arsenic concentrations in the water collected at a number of sites exceeded its guide value for the protection of aquatic life. The potential As contribution by snow in the area was low and was largely of lithospheric origin. The PCA analysis showed strong association of arsenic in sediments with the sediment mineralogical composition (Fe2O3, TiO2 and Mn). Arsenic in water was positively correlated with its concentration in the sediments and could potentially increase if the environmental/climate conditions change.

  4. A comparison of batch and single wafer high dose arsenic ion implantation techniques

    Energy Technology Data Exchange (ETDEWEB)

    Irwin, R.B.; Filo, A.J.; Kannan, V.C.; Feygenson, A.; Prematta, R.J.

    1989-04-01

    High dose, low energy (4x10/sup 15/ cm/sup -2/ at 15 keV) arsenic ion implantation into silicon was performed in batch and single wafer mode using medium and high current ion implanters. An investigation of implanted and annealed samples by Rutherford backscattering (RBS), transmission electron microscopy (TEM), thermal wave technique, and sheet resistance mapping showed little to no difference of arsenic profiles and residual damage between batch and single wafer implantation conditions when the sample temperature during implantation was kept below 120/sup 0/C. (orig.).

  5. A comparison of batch and single wafer high dose arsenic ion implantation techniques

    Science.gov (United States)

    Irwin, R. B.; Filo, A. J.; Kannan, V. C.; Feygenson, A.; Prematta, R. J.

    1989-04-01

    High dose, low energy (4×10 15 cm -2 at 15 keV) arsenic ion implantation into silicon was performed in batch and single wafer mode using medium and high current ion implanters. An investigation of implanted and annealed samples by Rutherford backscattering (RBS), transmission electron microscopy (TEM), thermal wave technique, and sheet resistance mapping showed little to no difference of arsenic profiles and residual damage between batch and single wafer implantation conditions when the sample temperature during implantation was kept below 120° C.

  6. Phytoremediation assessment of Gomphrena globosa and Zinnia elegans grown in arsenic-contaminated hydroponic conditions as a safe and feasible alternative to be applied in arsenic-contaminated soils of the Bengal Delta.

    Science.gov (United States)

    Signes-Pastor, A J; Munera-Picazo, S; Burló, F; Cano-Lamadrid, M; Carbonell-Barrachina, A A

    2015-06-01

    Several agricultural fields show high contents of arsenic because of irrigation with arsenic-contaminated groundwater. Vegetables accumulate arsenic in their edible parts when grown in contaminated soils. Polluted vegetables are one of the main sources of arsenic in the food chain, especially for people living in rural arsenic endemic villages of India and Bangladesh. The aim of this study was to assess the feasibility of floriculture in the crop rotation system of arsenic endemic areas of the Bengal Delta. The effects of different arsenic concentrations (0, 0.5, 1.0, and 2.0 mg As L(-1)) and types of flowering plant (Gomphrena globosa and Zinnia elegans) on plant growth and arsenic accumulation were studied under hydroponic conditions. Total arsenic was quantified using atomic absorption spectrometer with hydride generation (HG-AAS). Arsenic was mainly accumulated in the roots (72 %), followed by leaves (12 %), stems (10 %), and flowers (<1 %). The flowering plants studied did not show as high phytoremediation capacities as other wild species, such as ferns. However, they behaved as arsenic tolerant plants and grew and bloomed well, without showing any phytotoxic signs. This study proves that floriculture could be included within the crop rotation system in arsenic-contaminated agricultural soils, in order to improve food safety and also food security by increasing farmer's revenue.

  7. Waste-water impacts on groundwater: Cl/Br ratios and implications for arsenic pollution of groundwater in the Bengal Basin and Red River Basin, Vietnam.

    Science.gov (United States)

    McArthur, J M; Sikdar, P K; Hoque, M A; Ghosal, U

    2012-10-15

    Across West Bengal and Bangladesh, concentrations of Cl in much groundwater exceed the natural, upper limit of 10 mg/L. The Cl/Br mass ratios in groundwaters range up to 2500 and scatter along mixing lines between waste-water and dilute groundwater, with many falling near the mean end-member value for waste-water of 1561 at 126 mg/L Cl. Values of Cl/Br exceed the seawater ratio of 288 in uncommon NO(3)-bearing groundwaters, and in those containing measurable amounts of salt-corrected SO(4) (SO(4) corrected for marine salt). The data show that shallow groundwater tapped by tube-wells in the Bengal Basin has been widely contaminated by waste-water derived from pit latrines, septic tanks, and other methods of sanitary disposal, although reducing conditions in the aquifers have removed most evidence of NO(3) additions from these sources, and much evidence of their additions of SO(4). In groundwaters from wells in palaeo-channel settings, end-member modelling shows that >25% of wells yield water that comprises ≥10% of waste-water. In palaeo-interfluvial settings, only wells at the margins of the palaeo-interfluvial sequence contain detectable waste water. Settings are identifiable by well-colour survey, owner information, water composition, and drilling. Values of Cl/Br and faecal coliform counts are both inversely related to concentrations of pollutant As in groundwater, suggesting that waste-water contributions to groundwater in the near-field of septic-tanks and pit-latrines (within 30 m) suppress the mechanism of As-pollution and lessen the prevalence and severity of As pollution. In the far-field of such sources, organic matter in waste-water may increase groundwater pollution by As. Copyright © 2012. Published by Elsevier B.V.

  8. Arsenic, barium, strontium and uranium geochemistry and their utility as tracers to characterize groundwaters from the Espadán–Calderona Triassic Domain, Spain

    Energy Technology Data Exchange (ETDEWEB)

    Giménez-Forcada, Elena, E-mail: e.gimenez@igme.es [Instituto Geológico y Minero de España — IGME, Unidad de Salamanca, Azafranal 48, 37001 Salamanca (Spain); Vega-Alegre, Marisol [University of Valladolid — UVA, Department of Analytical Chemistry, Campus Miguel Delibes, Paseo Belén 7, 47011 Valladolid (Spain)

    2015-04-15

    A set of analytical data from the Espadán–Calderona Triassic Domain aquifers was processed using hierarchical agglomerative cluster analysis (HCA) and principal component analysis (PCA), to achieve a quantitative and independent approach to investigate the characteristics of groundwater composition and possible differences between groundwater flows from Triassic aquifers from the Espadán–Calderona Triassic Domain (Spain). Mineralization in the Triassic series has led to the presence of several metals and metalloids in groundwater, including As, Mn, Fe and U. These are associated with fresher bicarbonate groundwaters, characterized by lower Sr/Ba ratios. Levels containing sulfate evaporitic salt, which are interbedded through the Triassic series, seem to exert a strong influence on the chemistry of several groundwaters, characterized by calcium sulfate facies with high Sr concentration and high Sr/Ba ratios. The application of multivariate statistical techniques to the interpretation of analytical results allows the differentiation of groundwater types occurring in the Triassic aquifers and identification of the role of a number of minor or trace elements and their ratios that can be treated as hydrogeochemical tracers. With them it was possible to correlate the different recharge waters with the tectonic morphology of the Espadán–Calderona Triassic Domain. - Highlights: • Groundwater hydrochemistry of Espadán–Calderona Triassic Domain was investigated. • Multivariate statistical analysis and metal tracers differentiated groundwater types. • The Sr/Ba ratio and As and U concentrations are good indicators of groundwater flows. • The chemistry of groundwater flows correlates with structural morphology of recharge areas.

  9. Anaerobic arsenite oxidation with an electrode serving as the sole electron acceptor: A novel approach to the bioremediation of arsenic-polluted groundwater

    Energy Technology Data Exchange (ETDEWEB)

    Pous, Narcis [Laboratory of Chemical and Environmental Engineering (LEQUiA), Institute of the Environment, University of Girona, C/Maria Aurèlia Capmany, 69 E-17071 Girona (Spain); Casentini, Barbara; Rossetti, Simona; Fazi, Stefano [Water Research Institute (IRSA-CNR), National Research Council, Via Salaria Km 29.300, 00015 Monterotondo (Italy); Puig, Sebastià [Laboratory of Chemical and Environmental Engineering (LEQUiA), Institute of the Environment, University of Girona, C/Maria Aurèlia Capmany, 69 E-17071 Girona (Spain); Aulenta, Federico, E-mail: aulenta@irsa.cnr.it [Water Research Institute (IRSA-CNR), National Research Council, Via Salaria Km 29.300, 00015 Monterotondo (Italy)

    2015-02-11

    Highlights: • As(III) was oxidized to As(V) in a bioelectrochemical system. • A polarized graphite electrode served as electron acceptor. • Gammaproteobacteria were the dominating organisms at the electrode. - Abstract: Arsenic contamination of soil and groundwater is a serious problem worldwide. Here we show that anaerobic oxidation of As(III) to As(V), a form which is more extensively and stably adsorbed onto metal-oxides, can be achieved by using a polarized (+497 mV vs. SHE) graphite anode serving as terminal electron acceptor in the microbial metabolism. The characterization of the microbial populations at the electrode, by using in situ detection methods, revealed the predominance of gammaproteobacteria. In principle, the proposed bioelectrochemical oxidation process would make it possible to provide As(III)-oxidizing microorganisms with a virtually unlimited, low-cost and low-maintenance electron acceptor as well as with a physical support for microbial attachment.

  10. Groundwater Modeling of the Texas High Plains using Modflow

    Science.gov (United States)

    Hernandez, J. E.; Gowda, P. H.; Misra, D.; Marek, T.; Howell, T. A.

    2008-12-01

    The objective of this study was to develop and calibrate a groundwater model for a 4-county area in the Texas High Plains of the Ogallala Aquifer Region. This study is a major component of a comprehensive regional analysis of groundwater depletion in the Ogallala Aquifer Region with the purpose of understanding short- and long-term effects of existing and alternative land use scenarios on groundwater changes. A comprehensive geographic information system (GIS) database was developed for this purpose that included a recent land cover map. This 2008 land cover map was developed using Landsat satellite imagery with ground-truth points for Dallam, Sherman, Hartley, and Moore Counties in Texas. Other GIS layers included aquifer elevation contours, surficial geology, hydraulic conductivity contours, saturated thickness areas, well locations and piezometric heads, aquifer discharge and recharge areas, topography, hydrographic data, ecological regions, and soil type data. The hydrologic simulations were done using MODFLOW. Anticipated outcomes from this modeling effort include the effect of change in land use/land cover on sustainability of the aquifer life in the study region. Our results will be used to develop strategies to conserve groundwater in the Ogallala Aquifer beneath Central High Plains and improve regional water planning.

  11. Isotopic Abundances and Ratios in Arsenic Irradiated by High-Energy Neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Parker, W. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hall, J. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2010-06-07

    This document provides derivations of the 73As, 74As and 75As isotopic abundances and ratios in an arsenic sample irradiated by high-energy (14 MeV) neutrons for 0 ≤ t ≤ T, where T is short compared to the natural decay times of the reaction products (t1/2 (73As) ~ 80.3 d, t1/2 (74As) ~ 17.8 d). The document also outlines the historic approach used to analyze arsenic data from experiments.

  12. Seasonal Variation of Arsenic Concentration in Ground Water of Nawalparasi District of Nepal

    Directory of Open Access Journals (Sweden)

    Rajib Kumar Shrestha

    2014-03-01

    Full Text Available Ground water of southern part of Nepal, also known as Terai region where population density is relatively very high, has been contaminated with poisonous element Arsenic. This study has been carried out to determine variability of the level of arsenic contamination in groundwater with seasons of Pathkhauli village of Devgaun VDC and Mahuwa village of Manari VDC in Nawalparasi district, the western Terai district. Hydride Generation Atomic Absorption Spectrophotometer (HG-AAS and UV-visible Spectrophotometry was used for analysis. Total 55 groundwater samples in post-monsoon season and 45 groundwater samples in pre-monsoon season were collected. The level of arsenic contamination in groundwater was found above the Nepal interim standard of 50 ppb. Of the total 42 water samples from each pre- and post- monsoon seasons analyzed, 28 water samples (67.67% showed higher As-concentration in pre-monsoon season.

  13. The palaeosol model of arsenic pollution of groundwater tested along a 32 km traverse across West Bengal, India.

    Science.gov (United States)

    Hoque, M A; McArthur, J M; Sikdar, P K

    2012-08-01

    The distribution of As-pollution in groundwater of the deltaic aquifers of south-eastern Asia may be controlled by the subsurface distribution of palaeo-channel sediments (As-polluted groundwaters) and palaeo-interfluvial sediments (As-free groundwaters). To test this idea, termed the palaeosol model of As-pollution, we drilled 10 sites, analysed groundwater from 249 shallow wells (screened pollution in a further 531 wells. Our work was conducted along a 32-km traverse running W to E across southern West Bengal, India. At seven drill sites we logged a palaeo-interfluvial sequence, which occurs as three distinct units that together occupy 20 km of the traverse. These palaeo-interfluvial sequences yield As-free groundwaters from brown sands at depthpolluted groundwater in grey sands. Our findings confirm the predictions of the palaeosol model of As-pollution. We show again that well-colour can be used both to successfully predict the degree of As-pollution in groundwater, and to locate regions of buried palaeo-interfluve that will yield As-free groundwater for the foreseeable future. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. Sequencing and expression of two arsenic resistance operons with different functions in the highly arsenic-resistant strain Ochrobactrum tritici SCII24T

    Directory of Open Access Journals (Sweden)

    Chung Ana-Paula

    2008-06-01

    Full Text Available Abstract Background Arsenic (As is a natural metalloid, widely used in anthropogenic activities, that can exist in different oxidation states. Throughout the world, there are several environments contaminated with high amounts of arsenic where many organisms can survive. The most stable arsenical species are arsenate and arsenite that can be subject to chemically and microbiologically oxidation, reduction and methylation reactions. Organisms surviving in arsenic contaminated environments can have a diversity of mechanisms to resist to the harmful effects of arsenical compounds. Results The highly metal resistant Ochrobactrum tritici SCII24 was able to grow in media with arsenite (50 mM, arsenate (up to 200 mM and antimonite (10 mM. This strain contains two arsenic and antimony resistance operons (ars1 and ars2, which were cloned and sequenced. Sequence analysis indicated that ars1 operon contains five genes encoding the following proteins: ArsR, ArsD, ArsA, CBS-domain-containing protein and ArsB. The ars2 operon is composed of six genes that encode two other ArsR, two ArsC (belonging to different families of arsenate reductases, one ACR3 and one ArsH-like protein. The involvement of ars operons in arsenic resistance was confirmed by cloning both of them in an Escherichia coli ars-mutant. The ars1 operon conferred resistance to arsenite and antimonite on E. coli cells, whereas the ars2 operon was also responsible for resistance to arsenite and arsenate. Although arsH was not required for arsenate resistance, this gene seems to be important to confer high levels of arsenite resistance. None of ars1 genes were detected in the other type strains of genus Ochrobactrum, but sequences homologous with ars2 operon were identified in some strains. Conclusion A new strategy for bacterial arsenic resistance is described in this work. Two operons involved in arsenic resistance, one giving resistance to arsenite and antimonite and the other giving resistance

  15. Subchronic Arsenic Exposure Through Drinking Water Alters Lipid Profile and Electrolyte Status in Rats.

    Science.gov (United States)

    Waghe, Prashantkumar; Sarkar, Souvendra Nath; Sarath, Thengumpallil Sasindran; Kandasamy, Kannan; Choudhury, Soumen; Gupta, Priyanka; Harikumar, Sankarankutty; Mishra, Santosh Kumar

    2017-04-01

    Arsenic is a groundwater pollutant and can cause various cardiovascular disorders in the exposed population. The aim of the present study was to assess whether subchronic arsenic exposure through drinking water can induce vascular dysfunction associated with alteration in plasma electrolytes and lipid profile. Rats were exposed to arsenic as 25, 50, and 100 ppm of sodium arsenite through drinking water for 90 consecutive days. On the 91st day, rats were sacrificed and blood was collected. Lipid profile and the levels of electrolytes (sodium, potassium, and chloride) were assessed in plasma. Arsenic reduced high-density lipoprotein cholesterol (HDL-C) and HDL-C/LDL-C ratio, but increased the levels of triglycerides, total cholesterol, low-density lipoprotein cholesterol (LDL-C), and electrolytes. The results suggest that the arsenic-mediated dyslipidemia and electrolyte retention could be important mechanisms in the arsenic-induced vascular disorder.

  16. Impacts of physical and chemical aquifer heterogeneity on basin-scale solute transport: Vulnerability of deep groundwater to arsenic contamination in Bangladesh

    Science.gov (United States)

    Michael, Holly A.; Khan, Mahfuzur R.

    2016-12-01

    Aquifer heterogeneity presents a primary challenge in predicting the movement of solutes in groundwater systems. The problem is particularly difficult on very large scales, across which permeability, chemical properties, and pumping rates may vary by many orders of magnitude and data are often sparse. An example is the fluvio-deltaic aquifer system of Bangladesh, where naturally-occurring arsenic (As) exists over tens of thousands of square kilometers in shallow groundwater. Millions of people in As-affected regions rely on deep (≥150 m) groundwater as a safe source of drinking water. The sustainability of this resource has been evaluated with models using effective properties appropriate for a basin-scale contamination problem, but the extent to which preferential flow affects the timescale of downward migration of As-contaminated shallow groundwater is unknown. Here we embed detailed, heterogeneous representations of hydraulic conductivity (K), pumping rates, and sorptive properties (Kd) within a basin-scale numerical groundwater flow and solute transport model to evaluate their effects on vulnerability and deviations from simulations with homogeneous representations in two areas with different flow systems. Advective particle tracking shows that heterogeneity in K does not affect average travel times from shallow zones to 150 m depth, but the travel times of the fastest 10% of particles decreases by a factor of ∼2. Pumping distributions do not strongly affect travel times if irrigation remains shallow, but increases in the deep pumping rate substantially reduce travel times. Simulation of advective-dispersive transport with sorption shows that deep groundwater is protected from contamination over a sustainable timeframe (>1000 y) if the spatial distribution of Kd is uniform. However, if only low-K sediments sorb As, 30% of the aquifer is not protected. Results indicate that sustainable management strategies in the Bengal Basin should consider impacts of both

  17. Assessing the mechanisms controlling the mobilization of arsenic in the arsenic contaminated shallow alluvial aquifer in the blackfoot disease endemic area.

    Science.gov (United States)

    Liao, Vivian Hsiu-Chuan; Chu, Yu-Ju; Su, Yu-Chen; Lin, Po-Cheng; Hwang, Yaw-Huei; Liu, Chen-Wuing; Liao, Chung-Min; Chang, Fi-John; Yu, Chan-Wei

    2011-12-15

    High levels of arsenic in groundwater and drinking water represent a major health problem worldwide. Drinking arsenic-contaminated groundwater is a likely cause of blackfoot disease (BFD) in Taiwan, but mechanisms controlling the mobilization of arsenic present at elevated concentrations within aquifers remain understudied. Microcosm experiments using sediments from arsenic contaminated shallow alluvial aquifers in the blackfoot disease endemic area showed simultaneous microbial reduction of Fe(III) and As(V). Significant soluble Fe(II) (0.23±0.03 mM) in pore waters and mobilization of As(III) (206.7±21.2 nM) occurred during the first week. Aqueous Fe(II) and As(III) respectively reached concentrations of 0.27±0.01 mM and 571.4±63.3 nM after 8 weeks. We also showed that the addition of acetate caused a further increase in aqueous Fe(II) but the dissolved arsenic did not increase. We further isolated an As(V)-reducing bacterium native to aquifer sediments which showed that the direct enzymatic reduction of As(V) to the potentially more-soluble As(III) in pore water is possible in this aquifer. Our results provide evidence that microorganisms can mediate the release of sedimentary arsenic to groundwater in this region and the capacity for arsenic release was not limited by the availability of electron donors in the sediments.

  18. Analysis of geological structure and anthropological factors affecting arsenic distribution in the Lahore aquifer, Pakistan

    Science.gov (United States)

    Muhammad, Akhtar Malik; Zhonghua, Tang; Sissou, Zakari; Mohamadi, Bahaa; Ehsan, Muhsan

    2016-11-01

    This study investigated the potential factors affecting arsenic concentration in the groundwater system of Lahore, Pakistan. The effects of several factors such as population density (PD), pumping rate (PR), impermeable land use (LU), surface elevation (SE), and water-table elevation (WL) on arsenic concentration were studied in 101 union councils of Lahore. Forty single and multi-factor models were established using geographic information system (GIS) techniques to develop an arsenic contamination map and to investigate the most effective combinations among factors. Additionally, statistical tests were used to evaluate arsenic concentration between classes of the same single factor. The arsenic concentration in the Lahore aquifer varied from 0.001 to 0.143 mg L-1. The highest arsenic concentrations were detected in the Walled City and the town of Shahdara. Among the 40 raster models, groundwater arsenic concentration showed the best matching frequency with single-factor models for PD (50.70 %) and SE (47 %). Thus, PD and SE were used to develop an arsenic distribution raster map, and they were also used to study the effect of aquifer depth on arsenic concentration. PD was found to have hidden latent variables such as PR and LU. The shallow aquifer depth was negatively correlated with arsenic concentration ( r = -0.23) and positively with PR ( r = 0.15). Therefore, when there was high PR in wells with smaller aquifer depth, the arsenic concentration was high. The existing water treatment and alternative water resources are good options, which should be developed to deal with Lahore wells contaminated with arsenic at high concentrations.

  19. Magnitude of arsenic pollution in the Mekong and Red River Deltas - Cambodia and Vietnam

    Energy Technology Data Exchange (ETDEWEB)

    Berg, Michael [Swiss Federal Institute of Aquatic Science and Technology (Eawag), CH-8600 Dubendorf (Switzerland)]. E-mail: michael.berg@eawag.ch; Stengel, Caroline [Swiss Federal Institute of Aquatic Science and Technology (Eawag), CH-8600 Dubendorf (Switzerland); Trang, Pham Thi Kim [Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, Hanoi (Viet Nam); Hung Viet, Pham [Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, Hanoi (Viet Nam); Sampson, Mickey L. [Resource Development International-Cambodia (RDIC), P.O. Box 494, Phnom Penh (Cambodia); Leng, Moniphea [Resource Development International-Cambodia (RDIC), P.O. Box 494, Phnom Penh (Cambodia); Samreth, Sopheap [Resource Development International-Cambodia (RDIC), P.O. Box 494, Phnom Penh (Cambodia); Fredericks, David [Phnom Penh (Cambodia)

    2007-01-01

    Large alluvial deltas of the Mekong River in southern Vietnam and Cambodia and the Red River in northern Vietnam have groundwaters that are exploited for drinking water by private tube-wells, which are of increasing demand since the mid-1990s. This paper presents an overview of groundwater arsenic pollution in the Mekong delta: arsenic concentrations ranged from 1-1610 {mu}g/L in Cambodia (average 217 {mu}g/L) and 1-845 {mu}g/L in southern Vietnam (average 39 {mu}g/L), respectively. It also evaluates the situation in Red River delta where groundwater arsenic concentrations vary from 1-3050 {mu}g/L (average 159 {mu}g/L). In addition to rural areas, the drinking water supply of the city of Hanoi has elevated arsenic concentrations. The sediments of 12-40 m deep cores from the Red River delta contain arsenic levels of 2-33 {mu}g/g (average 7 {mu}g/g, dry weight) and show a remarkable correlation with sediment-bound iron. In all three areas, the groundwater arsenic pollution seem to be of natural origin and caused by reductive dissolution of arsenic-bearing iron phases buried in aquifers. The population at risk of chronic arsenic poisoning is estimated to be 10 million in the Red River delta and 0.5-1 million in the Mekong delta. A subset of hair samples collected in Vietnam and Cambodia from residents drinking groundwater with arsenic levels > 50 {mu}g/L have a significantly higher arsenic content than control groups (< 50 {mu}g/L). Few cases of arsenic related health problems are recognized in the study areas compared to Bangladesh and West Bengal. This difference probably relates to arsenic contaminated tube-well water only being used substantially over the past 7 to 10 years in Vietnam and Cambodia. Because symptoms of chronic arsenic poisoning usually take more than 10 years to develop, the number of future arsenic related ailments in Cambodia and Vietnam is likely to increase. Early mitigation measures should be a high priority.

  20. Determining the solid phases hosting arsenic in Mekong Delta sediments

    Science.gov (United States)

    Wucher, M.; Stuckey, J. W.; McCurdy, S.; Fendorf, S.

    2011-12-01

    The major river systems originating from the Himalaya deposit arsenic bearing sediment into the deltas of South and Southeast Asia. High rates of sediment and organic carbon deposition combined with frequent flooding leads to anaerobic processes that release arsenic into the pore-water. Arsenic concentrations in the groundwater of these sedimentary basins are often above the World Health Organization drinking water standard of 10 μg As L-1. As a result, 150 million people are at risk of chronic arsenic poisoning through water and rice consumption. The composition of the iron bearing phases hosting the arsenic in these deltaic sediments is poorly understood. Here we implemented a suite of selective chemical extractions to help constrain the types of arsenic bearing solid phases, which were complimented with synchrotron-based X-ray absorption spectroscopy and X-ray diffraction analyses to define the arsenic and iron mineralogy of the system. Sediment cores were collected in triplicate from a seasonally-inundated wetland in Cambodia at depths of 10, 50, 100, and 150 centimeters. We hypothesize that (i) arsenic will be predominantly associated with iron oxides, and (ii) the ratio of crystalline to amorphous iron oxides will increase with sediment depth (and age). We performed four selective extractions in parallel to quantify the various pools of arsenic. First, 1 M MgCl2 was used to extract electrostatically-bound arsenic (labile forms) from the sediment. Second, 1 M NaH2PO4 targeted strongly adsorbed arsenic. Third, 1 M HCl was used to liberated arsenic coprecipitated with amorphous Fe/Mn oxides, carbonates, and acid-volatile sulfides. Finally, a dithionite extraction was used to account for arsenic associated with reducible Fe/Mn oxides. Through this work, we identified the composition of the phases hosting arsenic at various depths through the soil profile, improving our understanding of how arsenic persists in the aquifer. In addition, defining the arsenic and

  1. Urinary arsenic metabolism in a Western Chinese population exposed to high-dose inorganic arsenic in drinking water: Influence of ethnicity and genetic polymorphisms

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Songbo [Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Key Lab of Etiology and Epidemiology, Education Bureau of Hei Long Jiang Province and Ministry of Health (23618104), Harbin 150081 (China); Wu, Jie [Laboratory of Medical Genetics, Harbin Medical University, Harbin 150081 (China); Li, Yuanyuan [Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Key Lab of Etiology and Epidemiology, Education Bureau of Hei Long Jiang Province and Ministry of Health (23618104), Harbin 150081 (China); Liu, Yan [Department of Health Statistics, Harbin Medical University, Harbin 150081 (China); Gao, Yanhui; Yao, Feifei [Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Key Lab of Etiology and Epidemiology, Education Bureau of Hei Long Jiang Province and Ministry of Health (23618104), Harbin 150081 (China); Qiu, Chuanying [Dongcheng District Center for Disease Control and Prevention, Beijing 100009 (China); Song, Li; Wu, Yu [Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Key Lab of Etiology and Epidemiology, Education Bureau of Hei Long Jiang Province and Ministry of Health (23618104), Harbin 150081 (China); Liao, Yongjian [Gansu Center for Disease Control and Prevention, 730020 (China); Sun, Dianjun, E-mail: hrbmusdj@163.com [Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Key Lab of Etiology and Epidemiology, Education Bureau of Hei Long Jiang Province and Ministry of Health (23618104), Harbin 150081 (China)

    2014-01-01

    To investigate the differences in urinary arsenic metabolism patterns of individuals exposed to a high concentration of inorganic arsenic (iAs) in drinking water, an epidemiological investigation was conducted with 155 individuals living in a village where the arsenic concentration in the drinking water was 969 μg/L. Blood and urine samples were collected from 66 individuals including 51 cases with skin lesions and 15 controls without skin lesions. The results showed that monomethylated arsenic (MMA), the percentage of MMA (%MMA) and the ratio of MMA to iAs (MMA/iAs) were significantly increased in patients with skin lesions as compared to controls, while dimethylated arsenic (DMA), the percentage of DMA (%DMA) and the ratio of DMA to MMA (DMA/MMA) were significantly reduced. The percent DMA of individuals with the Ala/Asp genotype of glutathione S-transferase omega 1 (GSTO1) was significantly lower than those with Ala/Ala. The percent MMA of individuals with the A2B/A2B genotype of arsenic (+ 3 oxidation state) methyltransferase (AS3MT) was significantly lower than those with AB/A2B. The iAs and total arsenic (tAs) content in the urine of a Tibetan population were significantly higher than that of Han and Hui ethnicities, whereas MMA/iAs was significantly lower than that of Han and Hui ethnicities. Our results showed that when exposed to the same arsenic environment, different individuals exhibited different urinary arsenic metabolism patterns. Gender and ethnicity affect these differences and above polymorphisms may be effectors too. - Highlights: • We first survey a village with high iAs content in the drinking water (969 μg/L). • 90 villagers suffered typical skin lesions with a morbidity rate of 58%. • Cases exhibited higher %MMA and MMA/iAs, and lower %DMA and DMA/MMA than controls. • Gender and ethnicity affect the differences of iAs methylation metabolism levels. • GSTO1 and AS3MT gene polymorphisms may be factors too.

  2. Quantifying Volume of Groundwater in High Elevation Meadows

    Science.gov (United States)

    Ciruzzi, D.; Lowry, C.

    2013-12-01

    Assessing the current and future water needs of high elevation meadows is dependent on quantifying the volume of groundwater stored within the meadow sediment. As groundwater dependent ecosystems, these meadows rely on their ability to capture and store water in order to support ecologic function and base flow to streams. Previous research of these meadows simplified storage by assuming a homogenous reservoir of constant thickness. These previous storage models were able to close the water mass balance, but it is unclear if these assumptions will be successful under future anthropogenic impacts, such as increased air temperature resulting in dryer and longer growing seasons. Applying a geophysical approach, ground-penetrating radar was used at Tuolumne Meadows, CA to qualitatively and quantitatively identify the controls on volume of groundwater storage. From the geophysical results, a three-dimensional model of Tuolumne Meadows was created, which identified meadow thickness and bedrock geometry. This physical model was used in a suite of numerical models simulating high elevation meadows in order to quantify volume of groundwater stored with temporal and spatial variability. Modeling efforts tested both wet and dry water years in order to quantify the variability in the volume of groundwater storage for a range of aquifer properties. Each model was evaluated based on the seasonal depth to water in order to evaluate a particular scenario's ability to support ecological function and base flow. Depending on the simulated meadows ability or inability to support its ecosystem, each representative meadow was categorized as successful or unsuccessful. Restoration techniques to increase active storage volume were suggested at unsuccessful meadows.

  3. Arsenic-doped high-resistivity-silicon epitaxial layers for integrating low-capacitance diodes

    NARCIS (Netherlands)

    Sakic, A.; Scholtes, T.L.M.; De Boer, W.B.; Golshani, N.; Derakhshandeh, J.; Nanver, L.K.

    2011-01-01

    An arsenic doping technique for depositing up to 40-μm-thick high-resistivity layers is presented for fabricating diodes with low RC constants that can be integrated in closely-packed configurations. The doping of the as-grown epi-layers is controlled down to 5 × 1011 cm−3, a value that is solely li

  4. Mode of occurrence of arsenic in high-As coals from endemic arsenosis areas in southwestern Guizhou Province, China

    Institute of Scientific and Technical Information of China (English)

    DING Zhen-hua; ZHENG Bao-shao; ZHUANG Min; HU Tian-dou

    2007-01-01

    The use of high As-bearing coals has caused more than 3,000 cases of arsenosis patients in southwest Guizhou Province, China. The mode of occurrence of arsenic in coal is an important key role in understanding its behavior during usage and damage pathway to human health. Coal samples from endemic arsenosis areas were analyzed with INAA, EMPA, SEM-EDX, LTA, XRD, XAFS, and sequential leaching experiment. Arsenic in pyrite is from under the limit of EMPA to 1.75%, and in most cases, the content of arsenic is lower than 0.5%. Besides pyrite and arsenopyrite, SEM-EDX combined with LTA and XRD find that sulfates, clay and phosphates also contain arsenic. XAFS shows that arsenic mainly exists in the form of As5+. More than 50% of arsenic stayes in residual solid and combined with organic matrix in two samples, but most arsenic is leached out in other samples. The occurrence of such exceptionally high As contents in coal and the fact that the arsenic is dominantly organically associated are unique observations.

  5. Associations of arsenic metabolites, methylation capacity, and skin lesions caused by chronic exposure to high arsenic in tube well water.

    Science.gov (United States)

    Yang, Linsheng; Chai, Yuanqing; Yu, Jiangping; Wei, Binggan; Xia, Yajuan; Wu, Kegong; Gao, Jianwei; Guo, Zhiwei; Cui, Na

    2017-01-01

    To investigate the interaction between skin lesion status and arsenic methylation profiles, the concentrations and proportions of arsenic metabolites in urine and arsenic methylation capacities of study subjects were determined. The results showed that the mean urinary concentrations of iAs (inorganic arsenic), MMA (monomethylarsonic acid), DMA (dimethylarsinic acid), and TAs (total arsenic) were 75.65, 68.78, 265.81, and 410.24 μg/L, respectively, in the skin lesions subjects. The highest values were observed in the multiple skin lesions subjects. Higher %iAs and %MMA, and lower %DMA, PMI (primary methylation index), and SMI (secondary methylation index) were found in skin lesions subjects. The multiple skin lesions subjects had highest %iAs and %MMA, and lowest %DMA, PMI, and SMI. The prevalence of skin lesions strongly, positively correlated with arsenic levels in drinking water. The elder persons also had higher frequency of skin lesions compared with younger persons. It can be concluded that arsenic levels in drinking water significantly affected the prevalence of skin lesions. Male subjects usually had higher proportions of skin lesions when compared with female subjects. Moreover, it may be concluded that MMA was significantly related to single skin lesion, whereas DMA and iAs were associated with multiple skin lesions. It seemed that MMA had greater toxicity to hyperkeratosis, whereas DMA and iAs had higher toxicity to depigmentation or pigmentation. © 2015 Wiley Periodicals, Inc. Environ Toxicol 32: 28-36, 2017.

  6. High Arsenic contamination in drinking water Hand-Pumps in Khap Tola, West Champaran, Bihar, India

    Directory of Open Access Journals (Sweden)

    Siddharth eBhatia

    2014-11-01

    Full Text Available This study tests the drinking water supply of a marginalized village community of Khap Tola in the state of Bihar, a state in Northern India. Based on hand pump drinking water sample testing and analysis, we found that there was high levels of arsenic (maximum value being 397 ppb , in excess of the WHO limits of 10ppb. Analysis showed 57% of the samples from private hand-pumps in the shallow aquifer zone of 15-35m have arsenic greater than 200 ppb. Using GIS overlay analysis technique it was calculated that 25% of the residential area in the village is under high risk of arsenic contamination. Further using USEPA guidelines, it was calculated that children age group 5-10 years are under high risk of getting cancer. The Hazard Quotient calculated for 21 children taken for study, indicated that children may have adverse non-carcinogenic health impacts, in the future, with continued exposure. Since the area adds a new arsenic contaminated place in India, further geochemical analysis and health assessment needs to be done in this district of West Champaran in, Bihar.

  7. Numerical modelling of groundwater flow to understand the impacts of pumping on arsenic migration in the aquifer of North Bengal Plain

    Science.gov (United States)

    Sikdar, P. K.; Chakraborty, Surajit

    2017-03-01

    In this paper, numerical simulations of regional-scale groundwater flow of North Bengal Plain have been carried out with special emphasis on the arsenic (As)-rich alluvium filled gap between the Rajmahal hills on the west and the Garo hills on the east. The proposed concern of this modelling arose from development that has led to large water table declines in the urban area of English Bazar block, Malda district, West Bengal and possible transport of As in the near future from the adjacent As-polluted aquifer. Groundwater occurs under unconfined condition in a thick zone of saturation within the Quaternary alluvial sediments. Modelling indicates that current pumping has significantly changed the groundwater flowpaths from pre-development condition. At the present pumping rate, the pumping wells of the urban area may remain uncontaminated till the next 25 yrs, considering only pure advection of water but some water from the As-polluted zone may enter wells by 50 yrs. But geochemical and other processes such as adsorption, precipitation, redox reaction and microbial activity may significantly retard the predicted rate by advective transport. In the rural areas, majority of the water pumped from the aquifer is for irrigation, which is continuously re-applied on the surface. The near-vertical nature of the flowpaths indicates that, where As is present or released at shallow depths, it will continue to occur in pumping wells. Modelling also indicates that placing all the pumping wells at depths below 100 m may not provide As-free water permanently.

  8. Numerical modelling of groundwater flow to understand the impacts of pumping on arsenic migration in the aquifer of North Bengal Plain

    Indian Academy of Sciences (India)

    P K Sikdar; Surajit Chakraborty

    2017-03-01

    In this paper, numerical simulations of regional-scale groundwater flow of North Bengal Plain have been carried out with special emphasis on the arsenic (As)-rich alluvium filled gap between the Rajmahal hills on the west and the Garo hills on the east. The proposed concern of this modelling arose from development that has led to large water table declines in the urban area of English Bazar block, Malda district, West Bengal and possible transport of As in the near future from the adjacent As-polluted aquifer. Groundwater occurs under unconfined condition in a thick zone of saturation within the Quaternaryalluvial sediments. Modelling indicates that current pumping has significantly changed the groundwater flowpaths from pre-development condition. At the present pumping rate, the pumping wells of the urban area may remain uncontaminated till the next 25 yrs, considering only pure advection of water but some water from the As-polluted zone may enter wells by 50 yrs. But geochemical and other processes such as adsorption, precipitation, redox reaction and microbial activity may significantly retard the predicted rate by advective transport. In the rural areas, majority of the water pumped from the aquifer is forirrigation, which is continuously re-applied on the surface. The near-vertical nature of the flowpaths indicates that, where As is present or released at shallow depths, it will continue to occur in pumping wells. Modelling also indicates that placing all the pumping wells at depths below 100 m may not provideAs-free water permanently.

  9. Microbial transformations of arsenic: Mobilization from glauconitic sediments to water

    Science.gov (United States)

    Mumford, Adam C.; Barringer, Julia L.; Benzel, William M.; Reilly, Pamela A.; Young, L.Y.

    2012-01-01

    In the Inner Coastal Plain of New Jersey, arsenic (As) is released from glauconitic sediment to carbon- and nutrient-rich shallow groundwater. This As-rich groundwater discharges to a major area stream. We hypothesize that microbes play an active role in the mobilization of As from glauconitic subsurface sediments into groundwater in the Inner Coastal Plain of New Jersey. We have examined the potential impact of microbial activity on the mobilization of arsenic from subsurface sediments into the groundwater at a site on Crosswicks Creek in southern New Jersey. The As contents of sediments 33–90 cm below the streambed were found to range from 15 to 26.4 mg/kg, with siderite forming at depth. Groundwater beneath the streambed contains As at concentrations up to 89 μg/L. Microcosms developed from site sediments released 23 μg/L of As, and active microbial reduction of As(V) was observed in microcosms developed from site groundwater. DNA extracted from site sediments was amplified with primers for the 16S rRNA gene and the arsenate respiratory reductase gene, arrA, and indicated the presence of a diverse anaerobic microbial community, as well as the presence of potential arsenic-reducing bacteria. In addition, high iron (Fe) concentrations in groundwater and the presence of iron-reducing microbial genera suggests that Fe reduction in minerals may provide an additional mechanism for release of associated As, while arsenic-reducing microorganisms may serve to enhance the mobility of As in groundwater at this site.