WorldWideScience

Sample records for groundwater arsenic pollution

  1. 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

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

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    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.

  3. 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

  4. 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

  5. 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.

  6. Groundwater arsenic contamination throughout China.

    Science.gov (United States)

    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.

  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. 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 Speciation in Groundwater: Role of Thioanions

    Science.gov (United States)

    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...

  10. 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.

  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. 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

  13. 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.

  14. Management of the Arsenic Groundwater System Lagunera - MEXICO

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

    2007-05-01

    Arsenic in drinking water is considered one of the most important environmental causes of cancer mortality in the world. Groundwater resources of the Comarca Lagunera region (Northern Mexico), which represents the main source of drinking water for more than 2 million people in the area, show arsenic concentrations ranging from 5 to 750 micro g/l. Large areas have concentrations quite above the Mexican standard of 25 micro g/l for human use and consumption. The aquifer is overexploited and the groundwater levels at the central part of the aquifer are drawn down more than 100 m in less than 50 years. The drawdown provoked the dissolution and migration of the geogenic existing arsenic within the aquifer. The presence of arsenic has been related to several potential sources. It was found out, that the main source is geothermal activity, less mining and the use of arsenical pesticides. The process of the geneses of the arsenic pollution implicates, that the highest content is on the bottom of the aquifer. Data analysis showed, that arsenic concentration is correlated to the age of the groundwater. "Older" water has higher arsenic content than "younger" water and the oldest water can be found at the bottom of the aquifer. Before 1950 the groundwater level in the Comarca Lagunera was close to the surface and there were only dug and shallow wells with low groundwater abstraction. The water was pumped from the upper parts of the aquifer and because this was "young" water it had low arsenic content. Then after 1950 a lot of wells, mainly for irrigation, were built and in 2002 there were 2350 active wells with an abstraction of about 1088 Mio cbm/year. In consequence to this the groundwater level decreased extraordinary. More and more "older" water was pumped and the arsenic content increased. Furthermore at the beginning of 1960 the river Nazas was canalized and lined, so that the natural groundwater recharge by infiltration from the river was stopped. By this way, the

  15. Tehran Groundwater Chemical Pollution

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    M- Shariatpanahi

    1990-06-01

    Full Text Available Seventy eight wells water sample of Tehran plain were examined to determine r its groundwaters chemical pollution. Tehran s groundwaters are slightly acidic and their total dissolved solids are high and are in the hard water category."nThe nitrate concentration of wells water of west region is less than per¬missible level of W.H.O. standard, whereas, the nitrate concentration of some of the other regions wells exceed W.H.O. standard which is indication of pollution"nwith municipal wastewaters. The concentration of toxic elements Cr, Cd, As, Hg and"ni Pb of some of the west, east and south regions wells of Tehran is more than per¬missible level of W.H.O. standard, whereas, the concentration of Cu, Zn,Mn and detergents is below W.H.O. standard."n1"nIn general, the amount of dissolved materials of Tehran s groundwaters and also"ni the potential of their contamination with nitrate is increased as Tehran s ground-"nwaters move further to the south, and even though, Tehran s groundwaters contamination with toxic elements is limited to the industrial west district, industrial-residential east and south districts, but»with regard to the disposal methods of"nt municipal and industrial wastewaters, if Tehran s groundwaters pollution continues,"nlocal contamination of groundwaters is likely to spread. So that finally their quality changes in such a way that this water source may become unfit for most domestic, industrial and agricultural uses. This survey shows the necessity of collection and treatment of Tehran s wastewaters and Prevention of the disposal of untreated wastewaters into the environment.

  16. 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.

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

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    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.

  18. 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.

  19. Arsenic Contaminated Groundwater and Its Treatment Options in Bangladesh

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    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.

  20. 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

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

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    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.

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

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    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.

  3. 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...

  4. 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...

  5. 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.

  6. 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.

  7. 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...

  8. Groundwater Pollution and Vulnerability Assessment.

    Science.gov (United States)

    Kurwadkar, Sudarshan

    2017-10-01

    Groundwater is a critical resource that serve as a source of drinking water to large human population and, provide long-term water for irrigation purposes. In recent years; however, this precious resource being increasingly threatened, due to natural and anthropogenic activities. A variety of contaminants of emerging concern such as pharmaceuticals and personal care products, perfluorinated compounds, endocrine disruptors, and biological agents detected in the groundwater sources of both developing and developed nations. In this review paper, various studies have been included that documented instances of groundwater pollution and vulnerability to emerging contaminants of concern, pesticides, heavy metals, and leaching potential of various organic and inorganic contaminants from poorly managed residual waste products (biosolids, landfills, latrines, and septic tanks etc.). Understanding vulnerability of groundwater to pollution is critical to maintain the integrity of groundwater. A section on managed artificial recharge studies is included to highlight the sustainable approaches to groundwater conservation, replenishment and sustainability. This review paper is the synthesis of studies published in last one year that either documented the pollution problems or evaluated the vulnerability of groundwater pollution.

  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. Arsenic and Associated Trace Metals in Texas Groundwater

    Science.gov (United States)

    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.

  11. 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

  12. Sedimentology and arsenic pollution in the Bengal Basin: insight into arsenic occurrence and subsurface geology.

    Science.gov (United States)

    Hills, Andrew; McArthur, John

    2014-05-01

    is more complex than previously thought. References 1. Goodbred, S. L. & Kuehl, S. A. 2000. Enormous Ganges-Brahmaputra sediment discharge during strengthened early Holocene monsoon. Geology, 28, 1083-1086. 2. Goodbred, S. L., Kuehl, S. A., Steckler, M. S., & Sarkar, M. H. 2003. Controls on facies distribution and stratigraphic preservation in the Ganges-Brahmaputra delta sequence. Sedimentary Geology, 155, 301-316. 3. Hoque, M. A., McArthur, J. M., & Sikdar, P. K. 2012. The palaeosol model of arsenic pollution of groundwater tested along a 32 km traverse across West Bengal, India. Science of the Total Environment, 431, 157-165. 4. McArthur, J. M., Ravenscroft, P., Banerjee, D. M., Milsom, J., Hudson-Edwards, K. A., Sengupta, S., Bristow, C., Sarkar, A., & Purohit, R. 2008. How palaeosols influence groundwater flow and arsenic pollution: A model from the Bengal Basin and its worldwide implication. Water Resources Research, 44, W11411, doi: 10.1029/2007WR0067552. 5. McArthur, J. M., Nath, B., Banerjee, D. M., Purohit, R., & Grassineau, N. 2011. Palaeosol control on groundwater flow and pollutant distribution: The example of arsenic. Environmental Science and Technology, 45, 1376-1383.

  13. 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.

  14. 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

  15. Groundwater pollution: are we monitoring appropriate parameters?

    CSIR Research Space (South Africa)

    Tredoux, G

    2004-01-01

    Full Text Available . In the literature, divergent approaches have identified various sets of pollutants and pollution indicators. This paper discusses international and local trends in groundwater monitoring for baseline studies and on-going pollution detection monitoring for a variety...

  16. 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.

  17. Detection and Remediation of Groundwater Pollution

    Institute of Scientific and Technical Information of China (English)

    王杰

    2016-01-01

    Groundwater is an important part of the water cycle and is also widely used as sources of drinking water. With the increasing de?velopment of groundwater exploitation, the pollution is becoming more and more serious. This paper talks about the main research direc?tions of groundwater pollution, the detection, the remediation and some conclusions.

  18. 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.

  19. Quality of our groundwater resources: arsenic and fluoride

    Science.gov (United States)

    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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. Arsenic Mobility and Groundwater Extraction in Bangladesh

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  6. 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

  7. 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

  8. Groundwater Pollution from Underground Coal Gasification

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In situ coal gasification poses a potential environmental risk to groundwater pollution although it depends mainly on local hydrogeological conditions.In our investigation, the possible processes of groundwater pollution originating from underground coal gasification (UCG) were analyzed.Typical pollutants were identified and pollution control measures are proposed.Groundwater pollution is caused by the diffusion and penetration of contaminants generated by underground gasification processes towards surrounding strata and the possible leaching of underground residue by natural groundwater flow after gasification.Typical organic pollutants include phenols, benzene, minor components such as PAHs and heterocyclics.Inorganic pollutants involve cations and anions.The natural groundwater flow after gasification through the seam is attributable to the migration of contaminants, which can be predicted by mathematical modeling.The extent and concentration of the groundwater pollution plume depend primarily on groundwater flow velocity, the degree of dispersion and the adsorption and reactions of the various contaminants.The adsorption function of coal and surrounding strata make a big contribution to the decrease of the contaminants over time and with the distance from the burn cavity.Possible pollution control measures regarding UCG include identifying a permanently, unsuitable zone, setting a hydraulic barrier and pumping contaminated water out for surface disposal.Mitigation measures during gasification processes and groundwater remediation after gasification are also proposed.

  9. 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.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  12. 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.

  13. 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.

  14. 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.

  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 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.

  17. 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.

  18. 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.

  19. Evaluation of Groundwater Pollution Nitrogen Fertilizer Using Expert System

    OpenAIRE

    Ta-oun, Mongkon; Daud, Mohamed; Bardaie, Mohd Zohadie

    2017-01-01

    An expert system was used to correlate the availability of nitrogen fertilizer with the vulnerability of groundwater to pollution in Peninsula Malaysia to identify potential groundwater quality problems. The expert system could predict the groundwater pollution potential under several conditions of agricultural activities and exiting environments. Four categories of groundwater pollution potential were identified base on an N-fertilizer groundwater pollution potential index. A groundwater pol...

  20. Groundwater contamination and pollution in micronesia

    Science.gov (United States)

    Detay, M.; Alessandrello, E.; Come, P.; Groom, I.

    1989-12-01

    This paper is an overview of groundwater contamination and pollution in th e main islands of the Federated States of Micronesia, the Republic of the Marshall Islands and the Republic of Belau (Palau). A strategy for the comprehensive protection of groundwater resources in the Trust Territory of the Pacific Islands is proposed.

  1. [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].

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

  4. Groundwater pollution: Are we monitoring appropriate parameters ...

    African Journals Online (AJOL)

    However, in practice groundwater quality monitoring is the main tool for timely ... quality is a specialised task for a hydrogeologist and a water quality monitoring expert. Although general prescriptions for waste management facilities exist these ... approaches have identified various sets of pollutants and pollution indicators.

  5. 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.

  6. 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.

  7. 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....

  8. 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...

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

    OpenAIRE

    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 ...

  10. 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.

  11. Modelling Urban diffuse pollution in groundwater

    Science.gov (United States)

    Jato, Musa; Smith, Martin; Cundy, Andrew

    2017-04-01

    Diffuse urban pollution of surface and ground waters is a growing concern in many cities and towns. Traffic-derived pollutants such as salts, heavy metals and polycyclic aromatic hydrocarbons (PAHs) may wash off road surfaces in soluble or particulate forms which later drain through soils and drainage systems into surface waters and groundwater. In Brighton, about 90% of drinking water supply comes from groundwater (derived from the Brighton Chalk block). In common with many groundwater sources the Chalk aquifer has been relatively extensively monitored and assessed for diffuse rural contaminants such as nitrate, but knowledge on the extent of contamination from road run-off is currently lacking. This project examines the transfer of traffic-derived contaminants from the road surface to the Chalk aquifer, via urban drainage systems. A transect of five boreholes have been sampled on a monthly basis and groundwater samples analysed to examine the concentrations of key, mainly road run-off derived, hydrocarbon and heavy metal contaminants in groundwater across the Brighton area. Trace concentrations of heavy metals and phenols have been observed in groundwater. Electrical conductivity changes in groundwater have also been used to assess local changes in ionic strength which may be associated with road-derived contaminants. This has been supplemented by systematic water and sediment sampling from urban gully pots, with further sampling planned from drainage and settlement ponds adjacent to major roads, to examine initial road to drainage system transport of major contaminants.

  12. 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

  13. Vulnerability to diffuse pollution of European soils and groundwater

    NARCIS (Netherlands)

    Meinardi CR; Beusen AHW; Bollen MJS; Klepper O; LBG; CWM

    1994-01-01

    From the Atlantic Ocean to the Ural Mountains, European soils and groundwater are threatened by diffuse pollution derived from various chemicals used in modern agriculture and by increased atmospheric deposition of pollutants. The investigated vulnerability of soils (including groundwater) to

  14. 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.

  15. Optimal dynamic management of groundwater pollutant sources.

    Science.gov (United States)

    Gorelick, S.M.; Remson, I.

    1982-01-01

    The linear programing-superposition method is presented for managing multiple sources of groundwater pollution over time. The method uses any linear solute transport simulation model to generate a unit source-concentration response matrix that is incorporated into a management model. -from Authors

  16. Integrating the Sciences to Investigate Groundwater Pollution

    Science.gov (United States)

    Grady, Julie R.; Madden, Andrew S.

    2010-01-01

    Investigations that integrate concepts from geological sciences with biology and chemistry are rare. The authors present an investigation that introduces high school students to microbe-mineral interactions by tying together anaerobic respiration, reduction reactions, metal ion solubility, and groundwater pollution. During the investigation,…

  17. Integrating the Sciences to Investigate Groundwater Pollution

    Science.gov (United States)

    Grady, Julie R.; Madden, Andrew S.

    2010-01-01

    Investigations that integrate concepts from geological sciences with biology and chemistry are rare. The authors present an investigation that introduces high school students to microbe-mineral interactions by tying together anaerobic respiration, reduction reactions, metal ion solubility, and groundwater pollution. During the investigation,…

  18. 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

  19. 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

  20. 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.

  1. 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 ...

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Reliability Analyses of Groundwater Pollutant Transport

    Energy Technology Data Exchange (ETDEWEB)

    Dimakis, Panagiotis

    1997-12-31

    This thesis develops a probabilistic finite element model for the analysis of groundwater pollution problems. Two computer codes were developed, (1) one using finite element technique to solve the two-dimensional steady state equations of groundwater flow and pollution transport, and (2) a first order reliability method code that can do a probabilistic analysis of any given analytical or numerical equation. The two codes were connected into one model, PAGAP (Probability Analysis of Groundwater And Pollution). PAGAP can be used to obtain (1) the probability that the concentration at a given point at a given time will exceed a specified value, (2) the probability that the maximum concentration at a given point will exceed a specified value and (3) the probability that the residence time at a given point will exceed a specified period. PAGAP could be used as a tool for assessment purposes and risk analyses, for instance the assessment of the efficiency of a proposed remediation technique or to study the effects of parameter distribution for a given problem (sensitivity study). The model has been applied to study the greatest self sustained, precipitation controlled aquifer in North Europe, which underlies Oslo`s new major airport. 92 refs., 187 figs., 26 tabs.

  7. 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

  8. 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.

  9. 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

  10. 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

  11. 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.

  12. The Mechanism of Nitrate Pollution in Soil and Groundwater

    Institute of Scientific and Technical Information of China (English)

    王志敏; 诸葛敏; 杨玉峥

    2013-01-01

    Soil and groundwater which are important natural resources are closely related with human health.It will be hard to recover,if it is polluted.Nitrate has become one of the most serious harmful substances contaminated in soil and groundwater.A large number of studies have shown that high fertilizer and irrigation was the main reason of soil and groundwater pollution.Pollution is mainly concentrated in agricultural developed area.

  13. 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.

  14. [Study on the risk assessment method of regional groundwater pollution].

    Science.gov (United States)

    Yang, Yan; Yu, Yun-Jiang; Wang, Zong-Qing; Li, Ding-Long; Sun, Hong-Wei

    2013-02-01

    Based on the boundary elements of system risk assessment, the regional groundwater pollution risk assessment index system was preliminarily established, which included: regional groundwater specific vulnerability assessment, the regional pollution sources characteristics assessment and the health risk assessment of regional featured pollutants. The three sub-evaluation systems were coupled with the multi-index comprehensive method, the risk was characterized with the Spatial Analysis of ArcMap, and a new method to evaluate regional groundwater pollution risk that suitable for different parts of natural conditions, different types of pollution was established. Take Changzhou as an example, the risk of shallow groundwater pollution was studied with the new method, and found that the vulnerability index of groundwater in Changzhou is high and distributes unevenly; The distribution of pollution sources is concentrated and has a great impact on groundwater pollution risks; Influenced by the pollutants and pollution sources, the values of health risks are high in the urban area of Changzhou. The pollution risk of shallow groundwater is high and distributes unevenly, and distributes in the north of the line of Anjia-Xuejia-Zhenglu, the center of the city and the southeast, where the human activities are more intense and the pollution sources are intensive.

  15. [Groundwater organic pollution source identification technology system research and application].

    Science.gov (United States)

    Wang, Xiao-Hong; Wei, Jia-Hua; Cheng, Zhi-Neng; Liu, Pei-Bin; Ji, Yi-Qun; Zhang, Gan

    2013-02-01

    Groundwater organic pollutions are found in large amount of locations, and the pollutions are widely spread once onset; which is hard to identify and control. The key process to control and govern groundwater pollution is how to control the sources of pollution and reduce the danger to groundwater. This paper introduced typical contaminated sites as an example; then carried out the source identification studies and established groundwater organic pollution source identification system, finally applied the system to the identification of typical contaminated sites. First, grasp the basis of the contaminated sites of geological and hydrogeological conditions; determine the contaminated sites characteristics of pollutants as carbon tetrachloride, from the large numbers of groundwater analysis and test data; then find the solute transport model of contaminated sites and compound-specific isotope techniques. At last, through groundwater solute transport model and compound-specific isotope technology, determine the distribution of the typical site of organic sources of pollution and pollution status; invest identified potential sources of pollution and sample the soil to analysis. It turns out that the results of two identified historical pollution sources and pollutant concentration distribution are reliable. The results provided the basis for treatment of groundwater pollution.

  16. 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.

  17. 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.

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

    Science.gov (United States)

    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.

  19. Biogeochemical dynamics of pollutants in Insitu groundwater remediation systems

    Science.gov (United States)

    Kumar, N.; Millot, R.; Rose, J.; Négrel, P.; Battaglia-Brunnet, F.; Diels, L.

    2010-12-01

    Insitu (bio) remediation of groundwater contaminants has been area of potential research interest in last few decades as the nature of contaminant encountered has also changed drastically. This gives tough challenge to researchers in finding a common solution for all contaminants together in one plume. Redox processes play significant role in pollutant dynamics and mobility in such systems. Arsenic particularly in reduced environments can get transformed into its reduced form (As3+), which is apparently more mobile and highly toxic. Also parallel sulfate reduction can lead to sulfide production and formation of thioarsenic species. On the other hand heavy metals (Zn, Fe, and Cd) in similar conditions will favour more stable metal sulfide precipitation. In the present work, we tested Zero Valent Iron (ZVI) in handling such issues and found promising results. Although it has been well known for contaminants like arsenic and chlorinated compounds but not much explored for heavy metals. Its high available surface area supports precipitation and co -precipitation of contaminants and its highly oxidizing nature and water born hydrogen production helps in stimulation of microbial activities in sediment and groundwater. These sulfate and Iron reducing bacteria can further fix heavy metals as stable metal sulfides by using hydrogen as potential electron donor. In the present study flow through columns (biotic and control) were set up in laboratory to understand the behaviour of contaminants in subsurface environments, also the impact of microbiology on performance of ZVI was studied. These glass columns (30 x 4cm) with intermediate sampling points were monitored over constant temperature (20°C) and continuous groundwater (up)flow at ~1ml/hr throughout the experiment. Simulated groundwater was prepared in laboratory containing sulfate, metals (Zn,Cd) and arsenic (AsV). While chemical and microbial parameters were followed regularly over time, solid phase has been

  20. 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

  1. 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...

  2. Strategies for the Engineered Phytoremediation of Mercury and Arsenic Pollution

    Energy Technology Data Exchange (ETDEWEB)

    Dhankher, Om Parkash; Meagher, Richard B.

    2003-03-26

    Phytoremediation is the use of plants to extract, transport, detoxify and/or sequester pollutants of the land, water or air. Mercury and arsenic are among the worst environmental pollutants, adversely affecting the health of hundreds of millions of people worldwide. We have demonstrated that plants can be engineered to take up and tolerate several times the levels of mercury and arsenic that would kill most plant species. Starting with methylmercury and/or ionic mercury contamination, mercury is detoxified, stored below or above ground, and even volatilized as part of the transpiration process and keeping it out of the food chain. Initial efforts with arsenate demonstrate that it can be taken up, transported aboveground, electrochemically reduced to arsenite in leaves and sequestered in thiol-rich peptide complexes. The transgenic mercury remediation strategies also worked in cultivated and wild plant species like canola, rice and cottonwood.

  3. Vulnerability to diffuse pollution of European soils and groundwater

    NARCIS (Netherlands)

    Meinardi CR; Beusen AHW; Bollen MJS; Klepper O; LBG; CWM

    1994-01-01

    From the Atlantic Ocean to the Ural Mountains, European soils and groundwater are threatened by diffuse pollution derived from various chemicals used in modern agriculture and by increased atmospheric deposition of pollutants. The investigated vulnerability of soils (including groundwater) to diffus

  4. 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

  5. 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

  6. 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).

  7. 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...

  8. 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.

  9. 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.

  10. 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.

  11. Groundwater vulnerability to pollution mapping of Ranchi district using GIS.

    Science.gov (United States)

    Krishna, R; Iqbal, J; Gorai, A K; Pathak, G; Tuluri, F; Tchounwou, P B

    2015-12-01

    Groundwater pollution due to anthropogenic activities is one of the major environmental problems in urban and industrial areas. The present study demonstrates the integrated approach with GIS and DRASTIC model to derive a groundwater vulnerability to pollution map. The model considers the seven hydrogeological factors [Depth to water table (D), net recharge (R), aquifer media (A), soil media (S), topography or slope (T), impact of vadose zone (I) and hydraulic Conductivity(C)] for generating the groundwater vulnerability to pollution map. The model was applied for assessing the groundwater vulnerability to pollution in Ranchi district, Jharkhand, India. The model was validated by comparing the model output (vulnerability indices) with the observed nitrate concentrations in groundwater in the study area. The reason behind the selection of nitrate is that the major sources of nitrate in groundwater are anthropogenic in nature. Groundwater samples were collected from 30 wells/tube wells distributed in the study area. The samples were analyzed in the laboratory for measuring the nitrate concentrations in groundwater. A sensitivity analysis of the integrated model was performed to evaluate the influence of single parameters on groundwater vulnerability index. New weights were computed for each input parameters to understand the influence of individual hydrogeological factors in vulnerability indices in the study area. Aquifer vulnerability maps generated in this study can be used for environmental planning and groundwater management.

  12. 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.

  13. 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

  14. 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 ...

  15. 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

  16. 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.

  17. Petroleum Pollution of Groundwater in Zibo and Its Prevention Measures

    Institute of Scientific and Technical Information of China (English)

    徐建芳; 武强; 李铎

    2003-01-01

    The source of ground water supply in Dawu is an extremely huge one in Shandong province. Now it is faced with serious pollution of petroleum in Hougao area. Aiming at this problem, the petroleum pollution in aeration zone and in groundwater was analyzed. The result shows that the contaminant of groundwater comes from the leaching of petroleum in the soil horizon of aeration zone through precipitation, and the quick flow of groundwater makes the convection dominate themigration of contaminant. So movement of groundwater controls the distribution of petroleum contaminant, which is consistent with the direction of ground flow. Building a groundwater closure zone in Hougao is an effective method to stop the contaminated groundwater flowing toward the water supply source of Dawu. The petroleum contaminant can be effectively reduced through using the aeration, biological and oxidation technologies.

  18. 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

  19. 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

  20. 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.

  1. Development of a decision support system for groundwater pollution assessment

    NARCIS (Netherlands)

    Kukuric, N.

    1999-01-01

    Computers have become the main tooi used in groundwater management. Computer software has been developed for storage, processing and presentation of information on groundwater pollution problems. Continuing demands for more efficiënt handling of information have resulted in increasing integration of

  2. LINEAR MODELS FOR MANAGING SOURCES OF GROUNDWATER POLLUTION.

    Science.gov (United States)

    Gorelick, Steven M.; Gustafson, Sven-Ake; ,

    1984-01-01

    Mathematical models for the problem of maintaining a specified groundwater quality while permitting solute waste disposal at various facilities distributed over space are discussed. The pollutants are assumed to be chemically inert and their concentrations in the groundwater are governed by linear equations for advection and diffusion. The aim is to determine a disposal policy which maximises the total amount of pollutants released during a fixed time T while meeting the condition that the concentration everywhere is below prescribed levels.

  3. Emerging policies to control nonpoint source pollution of groundwater

    Science.gov (United States)

    Harter, T.

    2014-12-01

    Water quality impairment is among the highest ranking public issues of concern in the developed world. While, in Europe and North America, many water quality programs have been put in place over the past half century, regulators difficulties tackling the geographically most widespread water quality degradation in these regions: pollution of groundwater (as opposed to surface water) from diffuse sources (as opposed to point sources), including contamination with nitrate (affecting drinking water supplies in rural areas and at the rural-urban interface) and salinity (affecting irrigation water quality). Other diffuse pollution contaminants include pesticides and emerging contaminants (e.g., antibiotics and pathogens from animal farming). The geographic and hydrologic characteristics of nonpoint source pollution of groundwater are distinctly different from other types of water pollution: individually liable sources are contiguous across the landscape, and internally heterogeneous in space and time. On annually aggregated time scales (most relevant to groundwater), sources are continuously emitting pollution, while pollution levels typically do not exceed MCLs by less than a factor 2. An analysis of key elements of existing water pollution policies to control groundwater pollution from diffuse sources demonstrates the lack of both, science and institutional capacity, while existing point-source approaches cannot be applied toward the control of diffuse pollution to groundwater. For the latter, a key to a successful policy is a tiered, three-way monitoring program based on proxy compliance metrics instead of direct measurement of pollutant discharge, research linking actual pollutant discharges to proxy metrics, and long-term regional groundwater monitoring to establish large scale, long-term trends. Several examples of emerging regulations from California and the EU are given to demonstrate these principles.

  4. 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.

  5. Stabilization of arsenic and chromium polluted soils using water treatment residues

    DEFF Research Database (Denmark)

    Nielsen, Sanne Skov

    Chromated Copper Arsenate (CCA) is a mixture of arsenic, chromium and copper salts which have widely been used for impregnation of wood. World-wide many contaminated sites and brownfields exist, where wood impregnation with CCA has taken place, resulting in soil contamination and leaching...... or other sorbents. Iron water treatment residues mainly consist of ferrihydrite, an oxidized iron oxy-hydroxide with a high reactivity and a large specific surface area with a high capacity for adsorption. Iron water treatment residues (Fe-WTR) are a by-product from treatment of groundwater to drinking...... water and can be used as a soil amendment to decrease the mobility of CCA in contaminated soil. Stabilization with Fe-WTR was tested at the Collstrop site in Hillerød, Denmark. The site has been polluted with a wide range of wood impregnation agents including CCA during 40 years of wood impregnating...

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Evaluation of Groundwater Pollution with Heavy Metals at the Oblogo No.1 Dumpsite in Accra, Ghana

    Directory of Open Access Journals (Sweden)

    Kodwo Beedu Keelson

    2014-07-01

    Full Text Available The aim of this research study was to evaluate the groundwater pollution risks from heavy metal contaminants near the de-commissioned Oblogo No.1 dumpsite using a combination of USEPA leachate estimation and migration models. The Hydraulic Evaluation of Landfill Performance (HELP model was used to determine leachate volumes from the base of the dumpsite whereas the Industrial Waste Evaluation Model (IWEM was used to determine contaminant concentrations at groundwater wells located at various distances from the dumpsite. It was observed that there is a wide variation in the concentration of the contaminants measured at different sampling periods between 2004 and 2011. Pollution risks from chromium, lead, manganese, cobalt and zinc were determined to be very low since the simulated contaminant concentrations in the wells were less than the reference ground water concentrations. However, the concentrations of cadmium, copper and arsenic were determined to be high enough to constitute a potential risk to groundwater wells which are down-gradient of the dumpsite. It was also determined that the minimum buffer distance of 360 m specified in the Ghana Landfill Guidelines may not ensure adequate protection for groundwater wells located down-gradient of the Oblogo No.1 dumpsite.

  14. 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.

  15. [Pollution of the groundwater in the city of Niamey, Niger].

    Science.gov (United States)

    Chippaux, J P; Houssier, S; Gross, P; Bouvier, C; Brissaud, F

    2002-06-01

    We conducted a study on chemical and bacteriological groundwater pollution in Niamey, a Sahelian city of some 700,000 inhabitants. A total of 22 wells and 24 bore-holes were selected on a geological and socio-economic basis. The superficial aquifers, located on each bank of the River Niger and connected to the wells, presented high levels of oxidizable nitrogen and bacteriological pollution (coliform and faecal Streptococcus) which make the water unfit for human consumption. The deep aquifer, which supplies pumps, was also polluted but to a lesser degree. Faecal pollution increased after the rainy season. The lack of sanitation in Niamey and the seepage of polluted matters from the superficial layers could explain this pollution. Eventually, the use of the groundwater could increase and constitute a major health risk for the majority of the inhabitants of Niamey.

  16. 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 ...

  17. 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.

  18. Arsenic pesticides and environmental pollution: exposure, poisoning, hazards and recommendations.

    Science.gov (United States)

    El-Bahnasawy, Mamdouh M; Mohammad, Amina El-Hosini; Morsy, Tosson A

    2013-08-01

    Arsenic is a metalloid element. Acute high-dose exposure to arsenic can cause severe systemic toxicity and death. Lower dose chronic arsenic exposure can result in subacute toxicity that can include peripheral sensorimotor neuropathy, skin eruptions, and hepatotoxicity. Long-term effects of arsenic exposure include an in Due to the physiologic effects of the arsenic on all body systems, thus, chronic arsenic-poisoned patient is a major nursing challenge. The critical care nurse provides valuable assessment and interventions that prevent major multisystem complications from arsenic toxicity.

  19. Nitrate pollution of groundwater; all right…, but nothing else?

    Science.gov (United States)

    Menció, Anna; Mas-Pla, Josep; Otero, Neus; Regàs, Oriol; Boy-Roura, Mercè; Puig, Roger; Bach, Joan; Domènech, Cristina; Zamorano, Manel; Brusi, David; Folch, Albert

    2016-01-01

    Contamination from agricultural sources and, in particular, nitrate pollution, is one of the main concerns in groundwater management. However, this type of pollution entails the entrance of other substances into the aquifer, as well as it may promote other processes. In this study, we deal with hydrochemical and isotopic analysis of groundwater samples from four distinct zones in Catalonia (NE Spain), which include 5 different aquifer types, to investigate the influence of fertilization on the overall hydrochemical composition of groundwater. Results indicate that intense fertilizer application, causing high nitrate pollution in aquifers, also homogenize the contents of the major dissolved ions (i.e.; Cl(-), SO4(2-), Ca(2+), Na(+), K(+), and Mg(2+)). Thus, when groundwater in igneous and sedimentary aquifers is compared, significant differences are observed under natural conditions for Cl(-), Na(+) and Ca(2+) (with p-values ranging from groundwater hydrochemistry (with R(2) values of 0.490, 0.609 and 0.470, for SO4(2-), Ca(2+) and Cl(-), respectively). Nevertheless, the increasing concentration of specific ions is not only attributed to agricultural pollution, but to their enhancing effect upon the biogeochemical processes that control water-rock interactions. Such results raise awareness that these processes should be evaluated in advance in order to assess an adequate groundwater resources management. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. 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).

  1. 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

  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. Potential Health Effects from Groundwater Pollution.

    Science.gov (United States)

    Goyer, Robert A.

    1985-01-01

    Discusses the growing awareness of potential toxicological effects of synthetic organic chemicals contaminating groundwater. Problems concerning pesticides, chlorination, epidemiologic studies, cancer, nephrotoxicity, and considerations of risk are addressed. Additional research in this area is advocated. (DH)

  4. 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...

  5. Survey of groundwater chemical pollution in the Borazjan plain

    OpenAIRE

    Jaber Mozafarizadeh; Zahra Sajadi

    2014-01-01

    Background: Nitrate due to its high water solubility, poor absorption and having stable composition in the water, has been studied as the best index to indicate groundwater contamination. Borazjan, located in the north of Bushehr province, is one of fertile plains which nitrate contamination of groundwater has occurred in the most parts of it. Detecting the source of pollution and the most vulnerable areas were the aims of this study. Material and Methods: In this study, hydrochemical quality...

  6. [Quantitative method of representative contaminants in groundwater pollution risk assessment].

    Science.gov (United States)

    Wang, Jun-Jie; He, Jiang-Tao; Lu, Yan; Liu, Li-Ya; Zhang, Xiao-Liang

    2012-03-01

    In the light of the problem that stress vulnerability assessment in groundwater pollution risk assessment is lack of an effective quantitative system, a new system was proposed based on representative contaminants and corresponding emission quantities through the analysis of groundwater pollution sources. And quantitative method of the representative contaminants in this system was established by analyzing the three properties of representative contaminants and determining the research emphasis using analytic hierarchy process. The method had been applied to the assessment of Beijing groundwater pollution risk. The results demonstrated that the representative contaminants hazards greatly depended on different research emphasizes. There were also differences between the sequence of three representative contaminants hazards and their corresponding properties. It suggested that subjective tendency of the research emphasis had a decisive impact on calculation results. In addition, by the means of sequence to normalize the three properties and to unify the quantified properties results would zoom in or out of the relative properties characteristic of different representative contaminants.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  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. 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.

  13. Spatial assessment of animal manure spreading and groundwater nitrate pollution

    Directory of Open Access Journals (Sweden)

    Roberta Infascelli

    2009-11-01

    Full Text Available Nitrate concentration in groundwater has frequently been linked to non-point pollution. At the same time the existence of intensive agriculture and extremely intensive livestock activity increases the potential for nitrate pollution in shallow groundwater. Nitrate used in agriculture could cause adverse effects on human and animal health. In order to evaluate the groundwater nitrate pollution, and how it might evolve in time, it is essential to develop control systems and to improve policies and incentives aimed at controlling the amount of nitrate entering downstream water systems. The province of Caserta in southern Italy is characterized by high levels of animal manure loading. A comparison between manure nitrogen production and nitrate concentration in groundwater was carried out in this area, using geostatistical tools and spatial statistics. The results show a discrepancy between modelling of nitrate leaching and monitoring of the groundwater and, moreover, no spatial correlation between nitrogen production in livestock farms and nitrate concentration in groundwater, suggesting that producers are not following the regulatory procedures for the agronomic use of manure. The methodology developed in this paper could be applied also in other regions in which European Union fertilization plans are not adequately followed.

  14. Arsenic pollution and fractionation in sediments and mine waste samples from different mine sites.

    Science.gov (United States)

    Larios, Raquel; Fernández-Martínez, Rodolfo; Álvarez, Rodrigo; Rucandio, Isabel

    2012-08-01

    A characterization of arsenic pollution and its associations with solid mineral phases in sediments and spoil heap samples from four different abandoned mines in Spain is performed. Three of them were mercury mines located in the same mining district, in the province of Asturias, and the other one, devoted to arsenic mining, is in the province of León. A sequential extraction procedure, especially developed for arsenic, was applied for the study of arsenic partitioning. Very high total arsenic concentrations ranging 300-67,000 mg·kg(-1) were found. Arsenic fractionation in each mine is broadly in accordance with the mineralogy of the area and the extent of the mine workings. In almost all the studied samples, arsenic appeared predominantly associated with iron oxyhydroxides, especially in the amorphous form. Sediments from cinnabar roasted piles showed a higher arsenic mobility as a consequence of an intense ore treatment, posing an evident risk of arsenic spread to the surroundings. Samples belonging to waste piles where the mining activity was less intense presented a higher proportion of arsenic associated with structural minerals. Nevertheless, it represents a long-term source of arsenic to the environment. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. A model for managing sources of groundwater pollution.

    Science.gov (United States)

    Gorelick, S.M.

    1982-01-01

    The waste disposal capacity of a groundwater system can be maximized while maintaining water quality at specified locations by using a groundwater pollutant source management model that is based upon linear programing and numerical simulation. The decision variables of the management model are solute waste disposal rates at various facilities distributed over space. A concentration response matrix is used in the management model to describe transient solute transport and is developed using the US Geological Survey solute transport simulation model. The management model was applied to a complex hypothetical groundwater system. -from Author

  16. 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.

  17. A molecular topology approach to predicting pesticide pollution of groundwater

    Science.gov (United States)

    Worrall , Fred

    2001-01-01

    Various models have proposed methods for the discrimination of polluting and nonpolluting compounds on the basis of simple parameters, typically adsorption and degradation constants. However, such attempts are prone to site variability and measurement error to the extent that compounds cannot be reliably classified nor the chemistry of pollution extrapolated from them. Using observations of pesticide occurrence in U.S. groundwater it is possible to show that polluting from nonpolluting compounds can be distinguished purely on the basis of molecular topology. Topological parameters can be derived without measurement error or site-specific variability. A logistic regression model has been developed which explains 97% of the variation in the data, with 86% of the variation being explained by the rule that a compound will be found in groundwater if 6 pollution at the molecular level and their application to agrochemical development and risk assessment is discussed.

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  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. 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.

  5. 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.

  6. 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....

  7. Review of emerging organic pollutants in groundwater in Slovenia

    Directory of Open Access Journals (Sweden)

    Anja Koroša

    2012-12-01

    Full Text Available Emerging organic compounds EOC are substances which have been only recently determined as pollutants,and substances which have been newly developed or discovered in the environment. EOC in groundwater cancause adverse effects on the environment and human health. They enter into the natural environment as a resultof various anthropogenic activities. The article provides an overview of emerging organic pollutants that occur ingroundwater. These compounds are drug residues, substances originating from personal care products, pesticides,veterinary products, food additives, nanomaterials, industrial and other compounds found in wastewater. Thearticle describes the main sources and the presence of EOC in groundwater, pathways and potential impacts(risks. An overview of EOC detection research in the world is presented. Within the review of Slovenian studiesthe investigations dealing with the determination of wide spectrum of EOC presence in groundwater, with drugresidues in groundwater and waste water, or with the development of analytical methods for these substanceswere analyzed. From the entire analysis we inferred that we must be aware of the possible presence of EOC riskin groundwatereven in small concentrations. To reduce the yet extent unknown risks, it is necessary to determineEOC threshold values in groundwater and their impact. In the future it will be necessary to identify new pollutants,to develop new analytical methods to determine their sources and routes, and in particular, to establishmonitoring for these substances.

  8. [Physical process based risk assessment of groundwater pollution in the mining area].

    Science.gov (United States)

    Sun, Fa-Sheng; Cheng, Pin; Zhang, Bo

    2014-04-01

    Case studies of groundwater pollution risk assessment at home and abroad generally start from groundwater vulnerability, without considering the influence of characteristic pollutants on the consequences of pollution too much. Vulnerability is the natural sensitivity of the environment to pollutants. Risk assessment of groundwater pollution should reflect the movement and distribution of pollutants in groundwater. In order to improve the risk assessment theory and method of groundwater pollution, a physical process based risk assessment methodology for groundwater pollution was proposed in a mining area. According to the sensitivity of the economic and social conditions and the possible distribution of pollutants in the future, the spatial distribution of risk levels in aquifer was ranged before hand, and the pollutant source intensity corresponding to each risk level was deduced accordingly. By taking it as the criterion for the classification of groundwater pollution risk assessment, the groundwater pollution risk in the mining area was evaluated by simulating the migration of pollutants in the vadose zone and aquifer. The result show that the risk assessment method of groundwater pollution based on physical process can give the concentration distribution of pollutants and the risk level in the spatial and temporal. For single punctuate polluted area, it gives detailed risk characterization, which is better than the risk assessment method that based on aquifer intrinsic vulnerability index, and it is applicable to the risk assessment of existing polluted sites, optimizing the future sites and providing design parameters for the site construction.

  9. Nitrate pollution of groundwater; all right…, but nothing else?

    Energy Technology Data Exchange (ETDEWEB)

    Menció, Anna, E-mail: anna.mencio@udg.edu [Grup de Geologia Aplicada i Ambiental (GAiA), Centre de Recerca en Geologia i Cartografia Ambiental (Geocamb), Deptartament de Ciències Ambientals, Facultat de Ciències, Universitat de Girona, 17071 Girona (Spain); Mas-Pla, Josep, E-mail: jmas@icra.cat [Grup de Geologia Aplicada i Ambiental (GAiA), Centre de Recerca en Geologia i Cartografia Ambiental (Geocamb), Deptartament de Ciències Ambientals, Facultat de Ciències, Universitat de Girona, 17071 Girona (Spain); Institut Català de Recerca de l’Aigua (ICRA) (Spain); Otero, Neus, E-mail: notero@ub.edu [Grup de Mineralogia Aplicada i Geoquímica de Fluids, Departament de Cristallografia, Mineralogia i Dipòsits Minerals, Facultat de Geologia, Universitat de Barcelona (UB), C/ Martí i Franquès, s/n – 08028 Barcelona (Spain); Regàs, Oriol [Grup de Geologia Aplicada i Ambiental (GAiA), Centre de Recerca en Geologia i Cartografia Ambiental (Geocamb), Deptartament de Ciències Ambientals, Facultat de Ciències, Universitat de Girona, 17071 Girona (Spain); Boy-Roura, Mercè [Institut Català de Recerca de l’Aigua (ICRA) (Spain); and others

    2016-01-01

    Contamination from agricultural sources and, in particular, nitrate pollution, is one of the main concerns in groundwater management. However, this type of pollution entails the entrance of other substances into the aquifer, as well as it may promote other processes. In this study, we deal with hydrochemical and isotopic analysis of groundwater samples from four distinct zones in Catalonia (NE Spain), which include 5 different aquifer types, to investigate the influence of fertilization on the overall hydrochemical composition of groundwater. Results indicate that intense fertilizer application, causing high nitrate pollution in aquifers, also homogenize the contents of the major dissolved ions (i.e.; Cl{sup -}, SO{sub 4}{sup 2-}, Ca{sup 2+}, Na{sup +}, K{sup +}, and Mg{sup 2+}). Thus, when groundwater in igneous and sedimentary aquifers is compared, significant differences are observed under natural conditions for Cl{sup -}, Na{sup +} and Ca{sup 2+} (with p-values ranging from < 0.001 to 0.038), and when high nitrate concentrations occur, these differences are reduced (most p-values ranged between 0.054 and 0.978). Moreover, positive linear relationships between nitrate and some ions are found indicating the magnitude of the fertilization impact on groundwater hydrochemistry (with R{sup 2} values of 0.490, 0.609 and 0.470, for SO{sub 4}{sup 2-}, Ca{sup 2+} and Cl{sup -}, respectively). Nevertheless, the increasing concentration of specific ions is not only attributed to agricultural pollution, but to their enhancing effect upon the biogeochemical processes that control water-rock interactions. Such results raise awareness that these processes should be evaluated in advance in order to assess an adequate groundwater resources management. - Highlights: • The effects of nitrate pollution have been evaluated in five different aquifer types • Statistical and multivariate analyses are used to identify groundwater changes • Agricultural pollution modifies

  10. Feasibility of phyto remediation of common soil and groundwater pollutants

    DEFF Research Database (Denmark)

    Trapp, Stefan; Rein, Arno; Clausen, Lauge Peter Westergaard

    his report is the D eliverable D 4.3 and was done within the Timbre project WP4. It introduces into the various clean - up techniques that apply plants, evaluates the feasibility of phytoremediation of common soil and groundwater pollutants, and the knowle dge collected for this purpose was applied...

  11. Feasibility of phytoremediation of common soil and groundwater pollutants

    DEFF Research Database (Denmark)

    Trapp, Stefan; Rein, Arno; Clause, Lauge

    2014-01-01

    This report is the D eliverable D 4.3 and was done within the Timbre project WP4. It introduces into the various clean - up techniques that apply plants, evaluates the feasibility of phytoremediation of common soil and groundwater pollutants, and the knowle dge collected for this purpose...

  12. 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.

  13. 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

  14. 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

  15. Groundwater Pollution Source Characterization of an Old Landfill

    DEFF Research Database (Denmark)

    Kjeldsen, Peter

    1993-01-01

    Only a few landfill investigations have focused on both the quantity and the quality of leachate as a source of groundwater pollution. The investigation of Vejen Landfill in Denmark included an introductionary historical survey (old maps, aerial photographs, interviews, etc.), leachate quality...... analysis, potential mapping of the groundwater surface below the landfill and leachate flow to surface waters and groundwater. The historical investigation showed that the original soil surface beneath the waste was a relatively heterogeneous mixture of boggy ground and sand soil areas. This indicated...... ditch and a southerly leach to the secondary aquifer were taking place. To evaluate the proportion of leachate discharging to the drainage ditch, piezometers were installed in the shallow leachate-affected aquifer. On the basis of several soundings, the groundwater surface was mapped and the expected...

  16. Groundwater Pollution Source Characterization of an Old Landfill

    DEFF Research Database (Denmark)

    Kjeldsen, Peter

    1993-01-01

    Only a few landfill investigations have focused on both the quantity and the quality of leachate as a source of groundwater pollution. The investigation of Vejen Landfill in Denmark included an introductionary historical survey (old maps, aerial photographs, interviews, etc.), leachate quality...... analysis, potential mapping of the groundwater surface below the landfill and leachate flow to surface waters and groundwater. The historical investigation showed that the original soil surface beneath the waste was a relatively heterogeneous mixture of boggy ground and sand soil areas. This indicated...... groundwater divides were located. These measurements indicated that approximately 50% of the leachate from the mixed waste discharged to the drainage ditch. This was supported by directly measuring the flux of leachate (as kilograms chloride per year) carried out by continuous gauging of water flow...

  17. Arsenic pollution and fractionation in sediments and mine waste samples from different mine sites

    Energy Technology Data Exchange (ETDEWEB)

    Larios, Raquel; Fernandez-Martinez, Rodolfo [Unidad de Espectroscopia, Division de Quimica, Departamento de Tecnologia, CIEMAT. Av. Complutense, 40, E-28040 Madrid (Spain); Alvarez, Rodrigo [Dpto. de Explotacion y Prospeccion de Minas, Universidad de Oviedo, ETS de Ingenieros de Minas, C/Independencia, 13, E-33004 Oviedo (Spain); Rucandio, Isabel, E-mail: isabel.rucandio@ciemat.es [Unidad de Espectroscopia, Division de Quimica, Departamento de Tecnologia, CIEMAT. Av. Complutense, 40, E-28040 Madrid (Spain)

    2012-08-01

    A characterization of arsenic pollution and its associations with solid mineral phases in sediments and spoil heap samples from four different abandoned mines in Spain is performed. Three of them were mercury mines located in the same mining district, in the province of Asturias, and the other one, devoted to arsenic mining, is in the province of Leon. A sequential extraction procedure, especially developed for arsenic, was applied for the study of arsenic partitioning. Very high total arsenic concentrations ranging 300-67,000 mg{center_dot}kg{sup -1} were found. Arsenic fractionation in each mine is broadly in accordance with the mineralogy of the area and the extent of the mine workings. In almost all the studied samples, arsenic appeared predominantly associated with iron oxyhydroxides, especially in the amorphous form. Sediments from cinnabar roasted piles showed a higher arsenic mobility as a consequence of an intense ore treatment, posing an evident risk of arsenic spread to the surroundings. Samples belonging to waste piles where the mining activity was less intense presented a higher proportion of arsenic associated with structural minerals. Nevertheless, it represents a long-term source of arsenic to the environment. - Highlights: Black-Right-Pointing-Pointer Arsenic fractionation in sediments from different mining areas is evaluated. Black-Right-Pointing-Pointer A sequential extraction scheme especially designed for arsenic partitioning is applied. Black-Right-Pointing-Pointer As associations with mineral pools is in accordance to the mineralogy of each area. Black-Right-Pointing-Pointer As distribution and mobility in each area depends on the extent of mining activity. Black-Right-Pointing-Pointer As occurs mainly associated with amorphous iron oxyhydroxides in all samples.

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. 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.

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

    Science.gov (United States)

    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.

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. 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,...

  11. Survey of groundwater chemical pollution in the Borazjan plain

    Directory of Open Access Journals (Sweden)

    Jaber Mozafarizadeh

    2014-11-01

    Full Text Available Background: Nitrate due to its high water solubility, poor absorption and having stable composition in the water, has been studied as the best index to indicate groundwater contamination. Borazjan, located in the north of Bushehr province, is one of fertile plains which nitrate contamination of groundwater has occurred in the most parts of it. Detecting the source of pollution and the most vulnerable areas were the aims of this study. Material and Methods: In this study, hydrochemical quality, especially in terms of nitrate, sulfate, chloride sodium, spatial and temporal variations and the origin of them in the groundwater of Borazjan plain, are studied. Groundwater samples from 12 wells were collected in April and August 2012 and assessed to determine the parameters of hydrochemistry and pollution. Results: Based on these results, severe nitrate contamination of groundwater, especially in the southern part of the plain, by agricultural activities, cesspool wells, domestic sewage and livestock and poultry wastewater the influence of the effluent from the aviculture, were occurred. Also, the quality of groundwater resources showed that concentration of Cl- , Na+, SO42- , and NO3- are more than standard limit and only in some areas of plain, concentration of ions such as NO3- and Na+ is less than the standard limit. Conclusion: According to the results of this study, using chemical fertilizers in terms of time period and amount of consumption should be properly managed. Furthermore, domestic wastewater, livestock and poultry wastewater should be controlled and the monitoring system for measuring the exact quantity and quality of groundwater resources must be completed.

  12. 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...

  13. 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

  14. 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

  15. 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

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

    Directory of Open Access Journals (Sweden)

    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. 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. 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

  19. 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

  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. Exophiala sideris, a novel black yeast isolated from environments polluted with toxic alkyl benzenes and arsenic.

    Science.gov (United States)

    Seyedmousavi, Seyedmojtaba; Badali, Hamid; Chlebicki, Andrzej; Zhao, Jingjun; Prenafeta-Boldú, Francesc Xavier; De Hoog, G Sybren

    2011-10-01

    A novel species of the black yeast genus Exophiala (order Chaetothyriales) is described. Strains were repeatedly obtained by enriching samples of wild berries from different plants, guano-rich soil and from oak railway ties treated with arsenic creosote under a toluene-rich atmosphere. An identical strain was encountered in a closed arsenic mine polluted by alkyl benzenes. Its potential use for purposes of bioremediation is discussed.

  2. Biological removal of arsenic pollution by soil fungi.

    Science.gov (United States)

    Srivastava, Pankaj Kumar; Vaish, Aradhana; Dwivedi, Sanjay; Chakrabarty, Debasis; Singh, Nandita; Tripathi, Rudra Deo

    2011-05-15

    Fifteen fungal strains were isolated from arsenic contaminated (range 9.45-15.63 mg kg(-1)) agricultural soils from the state of West Bengal, India. Five fungal strains were belonged to the Aspergillus and Trichoderma group each, however, remaining five were identified as the Neocosmospora, Sordaria, Rhizopus, Penicillium and sterile mycelial strain. All these fungal strains were cultivated on medium supplemented with 100, 500, 1000, 5000 and 10,000 mg l(-1) of sodium arsenate. After 30-day cultivation under laboratory conditions, radial growth of these strains was determined and compared with control. Toxicity and tolerance of these strains to arsenate were evaluated on the basis of tolerance index. Out of fifteen, only five fungal strains were found resistant and survived with tolerance index pattern as 0.956 (sterile mycelial strain)>0.311 (Rhizopus sp.)>0.306 (Neocosmospora sp.)>0.212 (Penicillium sp.)>0.189 (Aspergillus sp.) at 10,000 mg l(-1) of arsenate. The arsenic removal efficacy of ten fungal strains, tolerant to 5000 mg l(-1) arsenate, was also assayed under laboratory conditions for 21 days. All these strains were cultivated individually on mycological broth enriched with 10 mg l(-1) of arsenic. The initial and final pH of cultivating medium, fungal biomass and removal of arsenic by each fungal strain were evaluated. Fungal biomass of ten strains removed arsenic biologically from the medium which were ranged from 10.92 to 65.81% depending on fungal species. The flux of biovolatilized arsenic was determined indirectly by estimating the sum of arsenic content in fungal biomass and medium. The mean percent removal as flux of biovolatilized arsenic ranged from 3.71 to 29.86%. The most effective removal of arsenic was observed in the Trichoderma sp., sterile mycelial strain, Neocosmospora sp. and Rhizopus sp. fungal strains. These fungal strains can be effectively used for the bioremediation of arsenic-contaminated agricultural soils.

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

    Directory of Open Access Journals (Sweden)

    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. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  6. 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- ...

  7. ~(15)N Isotope Used for Study of Groundwater Nitrogen Pollution in Shijiazhuang City, China

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    Shijiazhuang City is the capital of Hebei province, China. Groundwater is the major water supply source for living and industry need of the city. Due to a rapid increase of population and development of industry and agriculture, a series of groundwater environmental problems are created. In the paper, the situation of groundwater pollution in Shijiazhuang city is reported. Based on the groundwater chemical data and ~(15)N measurement results both on groundwater and soils, the reason of groundwater nitra...

  8. 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.

  9. 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.

  10. A study of Heavy Metal Pollution in Groundwater of Malwa Region of Punjab, India: Current Status, Pollution and its Potential Health Risk

    Directory of Open Access Journals (Sweden)

    Rajni Sharma

    2017-03-01

    Full Text Available Among the different types of pollution, heavy metal pollution has become one of the major environmental issues in India. A number of studies show that high level of heavy metal exposure is a frequent cause of permanent intellectual and developmental disabilities. In this present study, the AAS method is used to determine the various heavy metal concentrations for 240 samples of Groundwater distributed in eight districts in Malwa Region of Punjab. The concentration values were compared with Standard Values given by BIS. The results showed that the maximum percentage of groundwater samples of Malwa region is beyond the permissible limits and that’s why not fit for drinking purposes and other domestic activities due to the presence of various heavy metals . The overall groundwater quality of Punjab for Arsenic, lead, Iron, Cobalt, Chromium, zinc and Mercury can also be detected and compared with BIS standards. The aim of this particular study was to investigate the distribution of Heavy metals in groundwater of Malwa Region of Punjab and its greater risks to public health. The results were compared with the recommended standards for drinking water of BIS to know the existing status and trend. Overall, water quality was found as unsatisfactory for drinking purposes in all the samples

  11. 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.

  12. 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

  13. 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

  14. Case reports: arsenic pollution in Thailand, Bangladesh, and Hungary.

    Science.gov (United States)

    Jones, Huw; Visoottiviseth, Pornsawan; Bux, M Khoda; Födényi, Rita; Kováts, Nora; Borbély, Gábor; Galbács, Zoltán

    2008-01-01

    Although arsenic contamination in the three countries described herein differs, a number of common themes emerge. In each country, the presence of arsenic is both long term and of geological origin. Moreover, in each of these countries, arsenic was only recently discovered to be a potential public health problem, having been first formally recognized in the 1980s or 1990s. In Bangledesh, exposure of the public to arsenic arose as a result of the search for microbially safe drinking water; this search resulted in the sinking of tube wells into aquifers. In Hungary, the natural bedrock geology was responsible for contamination of aquifer water. The genesis of arsenic contamination in Thailand arose primarily from small-scale alluvial mining activities, which mobilized geologically bound arsenic. Because of the complex chemistry of arsenic, and variability in where it is found and how it is bound, multiple mitigation methods must be considered for mitigating episodes of environmental contamination. The Ron Phibun region of Thailand has a 100-yr history of tin mining. A geological survey of the region was conducted in the mid-1990s by the Department of Mineral Resources and Department of Industry of Thailand, and was supported by the British Geological Society. Skin cancer in Thailand was first reported in 1987, in the southern part of the country; among other symptoms observed, there was evidence of IQ diminutions among the population. Arsenic water levels to 9,000 pg/L were reported; such levels are substantially above any guideline levels. A long-term plan to mitigate arsenic contamination was devised in 1998-2000. The plan involved removal of arsenic-contaminated land and improved management of mining wastes. However, at $22 million, the cost was deemed prohibitive for the regional Thai economy. An alternative solution of providing pipeline drinking water to the exposed population was also unsuccessful, either because arsenic contamination levels did not fall

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

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    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.

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

    Directory of Open Access Journals (Sweden)

    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

  17. Assessment of groundwater vulnerability and risk to pollution in Kathmandu Valley, Nepal.

    Science.gov (United States)

    Shrestha, Sangam; Semkuyu, Dickson John; Pandey, Vishnu P

    2016-06-15

    Groundwater vulnerability and risk assessment is a useful tool for groundwater pollution prevention and control. In this study, GIS based DRASTIC model have been used to assess intrinsic aquifer vulnerability to pollution whereas Groundwater Risk Assessment Model (GRAM) was used to assess the risk to groundwater pollution in the groundwater basin of Kathmandu Valley. Seven hydrogeological factors were used in DRASTIC model to produce DRASTIC Index (DI) map which represent intrinsic groundwater vulnerability to pollution of the area. The seven hydrogeological factors used were depth to water, net recharge, aquifer media, soil media, topography, impact of vadose zone, and hydraulic conductivity of aquifer. GIS based GRAM was used to produce likelihood of release of hazards, likelihood of detection of hazards, consequence of hazards and residual risk of groundwater contamination in terms of nitrate in the groundwater basin. It was found that more than 50% of the groundwater basin area in the valley is susceptible to groundwater pollution and these areas are mostly in Northern groundwater district Low and very low vulnerable areas account for only 13% and are located in Central and Southern groundwater districts. However after taking into account the barriers to groundwater pollution and likelihood of hazards release and detection, it was observed that most areas i.e. about 87% of the groundwater basin are at moderate residual risk to groundwater pollution. The resultant groundwater vulnerability and risk map provides a basis for policy makers and planner's ability to use information effectively for decision making at protecting the groundwater from pollutants. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Groundwater quality in Maharashtra, India: focus on nitrate pollution.

    Science.gov (United States)

    Gupta, Indrani; Salunkhe, Abhaysinh; Rohra, Nanda; Kumar, Rakesh

    2011-10-01

    Groundwater Survey and Development Agency (GSDA), Central Ground Water Board (CGWB) and Maharashtra Pollution Control Board (MPCB) have been carrying out groundwater quality monitoring at about 1407 monitoring locations in various districts of Maharashtra state in India. The groundwater quality data for pH, TDS, total hardness, sulphate, flouride and nitrate were compared with BIS: 10500:2004-2005 standards for drinking purpose. The results show that nitrate pollution is becoming more prevalent in groundwater of Maharashtra. Water quality data during the period 2007-2009 show that 544 locations out of 1407 locations exceeded 45 mgl(-1), the allowable NO3 level for drinking water. About 227 locations exceeded nitrate level beyond 100 mgl(-1). At 87 talukas in 23 districts of Maharashtra the NO3 levels exceeded the standard in all samples monitored during 2007-2009. The Buldana district with highest locations (27) had nitrate above 100 mgl(-1) followed by Amravati (24) and Akola (20) districts. At 7 talukas in 4 districts, fluoride was found above permissible limit of 1.5 mgl(-1), 100% of the time. 2 talukas in 2 districts of Maharashtra showed 100% non compliance of pH as per BIS standard of 6.5-8.5 mgl(-1). The districts having good to excellent quality of groundwater were Bhandara, Gondia, Kolhapur, Mumbai city, Mumbai Suburban, Nandurbar, Raigad, Ratnagiri, Satara, Sindhudurg, Thane and Washim. Vaijapur taluka in Aurangabad, Sinnar in Nashik and Kalambh taluka in Osmanabad have very poor water quality. Paithan taluka in Aurangabad, Shegaon taluka at Buldhana district, Amolner taluka at Jalgaon district and Jafrabad in Jalna district have water unsuitable for drinking.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Arsenic: it's extent of pollution and toxicosis: An animal perspective

    Directory of Open Access Journals (Sweden)

    Tapan Kumar Das

    2013-02-01

    Full Text Available Arsenic poisoning is now considered as one of the biggest environmental disaster and a major public health issue. Incidence of arsenicpoisoning has been reported from many parts of the world. While Bangladesh and West Bengal (India account for the most of the incidence, occasional reports from Mexico, Taiwan and mainland China have also appeared.It is a natural metalloid found in low concentrations in virtually every part of the environment as it is used in a wide variety of industrial applications, from computers to fireworks. Ground water arsenic is the major source of poisoning in animals and human. About 80% of ingested arsenic is absorbed and metabolized in liver and then excreted through urine and faeces while upon chronic exposure, it is deposited in liver, kidney and skin. Human populations are also being exposed to this poison by consuming the milk of affected animal.Inorganic forms of arsenic are more toxic compared to organic forms. Acute toxicity is rare in nature in comparison to chronic toxicity, which is prevalent in contaminated areas. Most non-ruminants are more susceptible to intoxication than ruminants. Chronic exposure of arsenic in animals and human beings causes severe adverse effects in the form of lowered immunity, diseases and production performances. [Vet World 2013; 6(1.000: 53-58

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

    Directory of Open Access Journals (Sweden)

    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.

  5. 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

  6. 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

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

    Science.gov (United States)

    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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. State of nitrate pollution in groundwater in South Africa

    CSIR Research Space (South Africa)

    Maherry, A

    2010-09-01

    Full Text Available source of drinking water; and 4. Identify areas for priority research and nitrate remediation. As is customary in South Africa, all nitrate and nitrite concentrations in this paper are expressed as an equivalent quantity of nitrogen (N) except where...: Groundwater Pollution in Africa, edited by Y. Xu and B. Usher, Taylor and Francis plc, London, UK. Van den Berg, E.C., Plarre, C., Van den Berg, H.M. and Thompson, M.W. 2008. The South African National Land Cover 2000. Agricultural Research Council...

  13. 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. 

  14. Mapping the groundwater vulnerability for pollution at the pan African scale.

    Science.gov (United States)

    Ouedraogo, Issoufou; Defourny, Pierre; Vanclooster, Marnik

    2016-02-15

    We estimated vulnerability and pollution risk of groundwater at the pan-African scale. We therefore compiled the most recent continental scale information on soil, land use, geology, hydrogeology and climate in a Geographical Information System (GIS) at a resolution of 15 km × 15 km and at the scale of 1:60,000,000. The groundwater vulnerability map was constructed by means of the DRASTIC method. The map reveals that groundwater is highly vulnerable in Central and West Africa, where the watertable is very low. In addition, very low vulnerability is found in the large sedimentary basins of the African deserts where groundwater is situated in very deep aquifers. The groundwater pollution risk map is obtained by overlaying the DRASTIC vulnerability map with land use. The northern, central and western part of the African continent is dominated by high pollution risk classes and this is very strongly related to shallow groundwater systems and the development of agricultural activities. Subsequently, we performed a sensitivity analysis to evaluate the relative importance of each parameter on groundwater vulnerability and pollution risk. The sensitivity analysis indicated that the removal of the impact of vadose zone, the depth of the groundwater, the hydraulic conductivity and the net recharge causes a large variation in the mapped vulnerability and pollution risk. The mapping model was validated using nitrate concentration data of groundwater as a proxy of pollution risk. Pan-African concentration data were inferred from a meta-analysis of literature data. Results shows a good match between nitrate concentration and the groundwater pollution risk classes. The pan African assessment of groundwater vulnerability and pollution risk is expected to be of particular value for water policy and for designing groundwater resources management programs. We expect, however, that this assessment can be strongly improved when better pan African monitoring data related to groundwater

  15. 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.

  16. 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

  17. Investigations of air and groundwater pollution of the rural environment

    Energy Technology Data Exchange (ETDEWEB)

    Kerenyi, Attila; Csorba, Peter (Institute of Applied Landscape Geography, Kossuth L. University, Debrecen (Hungary))

    1993-12-01

    Within the framework of landscape investigations in the environment of Cserepfalu-Bogacs, air and groundwater pollution was regularly monitored. Automatic instruments were used to measure SO[sub 2] content of the air for one day, and NO[sub x] content for the following day. Characteristic periods of the year were selected for air pollution, so that several weeks of continuous measurements in each season were obtained. The air pollution data measured in Cserepfalu are nearly always characteristic of the wider environment (background values). In the centre of Bogacs, SO[sub 2] pollution as a result of winter heating can be well observed; the amount of NO[sub x] is mostly determined by the increased traffic in summer. During a windless and very cold November, SO[sub 2] contamination in Bogacs greatly exceeded the permissible level. Groundwater examinations were carried out in the village of Cserepfalu between 1989 and 1990. The first measurements in Cserepfalu, between May and September 1988, showed little contamination, and the nitrate content was practically constant at 30 mg dm[sup -3] in the four main wells. In June 1989 the nitrate content of the water in these wells rose 4-7-fold by the end of the month. The characteristic nitrate concentration was found to be 80-150 mg dm[sup -3] and 150-250 mg dm[sup -3], but there were some places with values above 400 mg dm[sup -3]. These high values were found on the outskirts of the village, in an intensively cultivated agricultural area; thus the agricultural origin of the contamination is probable

  18. Effectiveness of amendments on the spread and phytotoxicity of contaminants in metal-arsenic polluted soil

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, V., E-mail: vga220@ual.es [Departamento de Edafologia y Quimica Agricola, ESI CITE IIB, Universidad de Almeria, Carretera de Sacramento s/n, 04129 Almeria (Spain); Garcia, I.; Del Moral, F.; Simon, M. [Departamento de Edafologia y Quimica Agricola, ESI CITE IIB, Universidad de Almeria, Carretera de Sacramento s/n, 04129 Almeria (Spain)

    2012-02-29

    Highlights: Black-Right-Pointing-Pointer The effectiveness of soil amendments was studied in lixiviates and in pore water. Black-Right-Pointing-Pointer Heavy metals and arsenic showed different partitioning. Black-Right-Pointing-Pointer The amendment which was effective against arsenic was not effective against metals. Black-Right-Pointing-Pointer The amendment that fixed metals increased the arsenic concentration in lixiviates. Black-Right-Pointing-Pointer Using amendments in combination did not improve the effectiveness. - Abstract: A metal-arsenic polluted soil from sulphide-mine waste was treated, in all possible combinations, with two different amounts of marble sludge (98% CaCO{sub 3}), compost (41% organic carbon), and Byferrox (70% Fe). Lixiviate and pore water from each treated and untreated soil were analysed, and lettuce-seed bioassays were performed. None of the treatments decreased the electrical conductivity of lixiviates or the concentrations of all pollutants found in both solutions. Marble sludge and compost increased the pH values and decreased the zinc, cadmium, copper, and lead concentrations in both solutions while increasing the arsenic concentrations in the lixiviates. Byferrox did not alter the physicochemical parameters or the concentrations of zinc, cadmium, copper, or lead in either solution but significantly decreased the arsenic concentrations in pore water. Compared with the Byferrox treatment, the mixture of marble sludge and Byferrox decreased redox potential values, increasing the arsenic concentrations in both solutions and the electrical conductivity of the pore water. All lixiviates were highly phytotoxic and seeds did not germinate. Pore-water phytotoxicity was related to electrical conductivity values and heavy-metal concentrations. The combination of marble sludge and compost was most effective at diminishing toxicity in lettuce. The soils treated with Byferrox, alone or mixed with marble sludge or compost, were the most

  19. 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.

  20. 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.

  1. 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.

  2. [Research of early-warning method for regional groundwater pollution based on risk management].

    Science.gov (United States)

    Bai, Li-Ping; Wang, Ye-Yao; Guo, Yong-Li; Zhou, You-Ya; Liu, Li; Yan, Zeng-Guang; Li, Fa-Sheng

    2014-08-01

    Groundwater is the main source of water supply in China, and China's overall situation of groundwater pollution is not optimistic at present. Groundwater pollution risk evaluation and early-warning are the effective measures to prevent groundwater pollution. At present, research of groundwater early-warning method at home and abroad is still at the exploratory stage, and the sophisticated technology has not been developed for reference. This paper briefly described the data and technological demand of the early-warning method in different scales, and the main factors influencing the early-warning results of groundwater pollution were classified as protection performance of geological medium, characteristics of pollution sources, groundwater dynamics and groundwater value. Then the main early-warning indexes of groundwater pollution were screened to establish the early-warning model of regional or watershed scale by the index overlay method. At last, the established early-warning model was used in Baotou plain, and the different early-warning grades were zoned by the model. The research results could provide scientific support for the local management department to protect the groundwater resources.

  3. Arsenic: it's extent of pollution and toxicosis: An animal perspective

    OpenAIRE

    Tapan Kumar Das; Debashis Roy; Shalini Vaswani

    2013-01-01

    Arsenic poisoning is now considered as one of the biggest environmental disaster and a major public health issue. Incidence of arsenicpoisoning has been reported from many parts of the world. While Bangladesh and West Bengal (India) account for the most of the incidence, occasional reports from Mexico, Taiwan and mainland China have also appeared.It is a natural metalloid found in low concentrations in virtually every part of the environment as it is used in a wide variety of industrial appli...

  4. 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

  5. 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.

  6. 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。

  7. 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.

  8. 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.

  9. Arsenic pollution and its treatment in Yangzonghai lake in China: In situ remediation.

    Science.gov (United States)

    Chen, Jing; Wang, Shixiong; Zhang, Shu; Yang, Xiangjun; Huang, Zhangjie; Wang, Chong; Wei, Qunyan; Zhang, Genlin; Xiao, Jun; Jiang, Fengzhi; Chang, Jun; Xiang, Xing; Wang, Juan

    2015-12-01

    In this study, the effect of direct atomization and spraying a ferric chloride (FeCl3) solution to decrease the arsenic concentration and its pollution in Yangzonghai Lake, China, was investigated. Ten ships were used for spraying 6-8t of FeCl3 in the lake every day since October 2009. After spraying, the average concentration of arsenic in Yangzonghai Lake, which has an area of 31 km(2), an average depth of 20 m, and a water storage capacity of 604 million m(3), started to decrease from 0.117 mg L(-1). On 20 September 2010, the lowest arsenic level of 0.021 mg L(-1) was attained, with an arsenic removal rate as high as 82.0%. However, the source of pollution was not eliminated, and local rainfall mainly occurred in September; hence, arsenic concentration from October to December increased to 0.078 mg L(-1). At the beginning of 2011, the As concentration decreased and remained at 0.025-0.028 mg L(-1) from May to September. During the 2 years of FeCl3 treatment, the water quality improved from V Class to II-III Class of the Chinese standards, which remained consistent for 12 months. The total cost for this in situ water treatment was 29 million RMB, which was less than a hundredth of the expected expenditure of 4-7 billion RMB. The treatment method achieved goals such as high arsenic removal rate, easy operation, low cost, and ecological security. In this study, the changing patterns of the concentration of arsenic in Yangzonghai Lake from June 2008 to December 2014 were analyzed, and the following problems were discussed: the stability of iron-arsenic precipitates in the lake, the concentrations of ferric and chloride ions in the lake, the pH of the lake during treatment, the stability of iron-arsenic precipitates in the lakebed sediments, and the variation of phytoplankton species in the lake.

  10. 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...

  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

    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.

  12. 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.

  13. 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.

  14. [Geographic information system based spatial analysis on chronic arsenic poisoning in a tin mining area, Thailand].

    Science.gov (United States)

    Zhang, Jianjun; Wu, Liping; Lin, Kun

    2007-05-01

    To explore the spatial features of arsenic contamination and its association with chronic arsenic poisoning in a tin mining area of Thailand. Geographic information system(GIS) was built up with integration of arsenic concentration in varied environmental media and occurring location data of chronic arsenism patients. Then, the spatial interpolation (IDW), buffer zoning, query and rank correlation analysis were applied. Groundwater and surface farming land were classified according to local environmental arsenic standards; the relative risk areas were identified. The incidence of chronic arsenic poisoning was significantly correlated with arsenic level in groundwater and soil type (P water soluble arsenic in soil (P > 0.05). The arsenic content in drinking water could be critical to chronic arsenic poisoning. The soil type could be an important factor affecting such poisoning. Trend analysis in GIS could provide a valuable tool for understanding the pollution situation and disease surveillance.

  15. Levels of toxic arsenic species in native terrestrial plants from soils polluted by former mining activities.

    Science.gov (United States)

    García-Salgado, Sara; Quijano, M Ángeles

    2014-03-01

    Ten native terrestrial plants from soils polluted by former mining activities (Mónica mine, NW Madrid, Spain), with high total arsenic concentration levels (up to 3500 μg g(-1)), have been studied to determine the fraction of arsenic present as toxic forms (inorganic and methylated species), which present a higher mobility and therefore the potential risk associated with their reintegration into the environment is high. Roots and aboveground parts were analyzed separately to assess possible transformations from translocation processes. Extractions were carried out with deionized water by microwave-assisted extraction at a temperature of 90 °C and three extraction steps of 7.5 min each. Total extracted arsenic concentrations were determined by inductively coupled plasma atomic emission spectrometry, showing extraction percentages from 9 to 39% (calculated as the ratio between total extracted arsenic (Asext) and total arsenic (AsT) concentrations in plants). Speciation studies, performed by high performance liquid chromatography-photo-oxidation-hydride generation-atomic fluorescence spectrometry, showed the main presence of arsenate (As(v)) (up to 350 μg g(-1)), followed by arsenite (As(iii)), in both plant parts. Monomethylarsonic acid (MMA) and trimethylarsine oxide (TMAO) were also found only in some plants. On the other hand, the use of 0.5 mol L(-1) acetic acid as an extractant led to higher extraction percentages (33-87%), but lower column recoveries, probably due to the extraction of arsenic compounds different to the toxic free ions studied, which may come from biotransformation mechanisms carried out by plants to reduce arsenic toxicity. However, As(v) concentrations increased up to 800 μg g(-1) in acid medium, indicating the probable release of As(v) from organoarsenic compounds and therefore a higher potential risk for the environment.

  16. 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

  17. Effectiveness of amendments on the spread and phytotoxicity of contaminants in metal-arsenic polluted soil.

    Science.gov (United States)

    González, V; García, I; Del Moral, F; Simón, M

    2012-02-29

    A metal-arsenic polluted soil from sulphide-mine waste was treated, in all possible combinations, with two different amounts of marble sludge (98% CaCO3), compost (41% organic carbon), and Byferrox (70% Fe). Lixiviate and pore water from each treated and untreated soil were analysed, and lettuce-seed bioassays were performed. None of the treatments decreased the electrical conductivity of lixiviates or the concentrations of all pollutants found in both solutions. Marble sludge and compost increased the pH values and decreased the zinc, cadmium, copper, and lead concentrations in both solutions while increasing the arsenic concentrations in the lixiviates. Byferrox did not alter the physicochemical parameters or the concentrations of zinc, cadmium, copper, or lead in either solution but significantly decreased the arsenic concentrations in pore water. Compared with the Byferrox treatment, the mixture of marble sludge and Byferrox decreased redox potential values, increasing the arsenic concentrations in both solutions and the electrical conductivity of the pore water. All lixiviates were highly phytotoxic and seeds did not germinate. Pore-water phytotoxicity was related to electrical conductivity values and heavy-metal concentrations. The combination of marble sludge and compost was most effective at diminishing toxicity in lettuce. The soils treated with Byferrox, alone or mixed with marble sludge or compost, were the most phytotoxic.

  18. 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.

  19. 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.

  20. 环境中砷污染治理的研究现状%Research Status of Arsenic Pollution Treatment

    Institute of Scientific and Technical Information of China (English)

    邹小丽; 杨智末; 林鹏; 黄叔贤

    2014-01-01

    环境中的砷污染给人类造成了很大的危害。本文阐述了国内外砷污染的状况,总结了水体和土壤的砷污染治理的研究现状。%Arsenic pollution has caused great damage to human. In this article, the situation of arsenic pollution is expounded, the research status on treatment of water and soil which has arsenic contaminant is summarized.

  1. The Effect of Flow on Pollution and Remediation in Groundwater

    Institute of Scientific and Technical Information of China (English)

    Moiwo J. Paul

    2003-01-01

    Flow, solute transport and pollution remediation through attenuation in unconsolidated porous media were investigated in this study. The variables used in the investigation include soil texture, porosity, topography and hydraulic conductivity. The study revealed that hydraulic conductivity is highly dependent on soil texture, porosity and topography.Hydraulic conductivity was noted to have a controlling influence on groundwater flow and residence time, and the degree of natural attenuation in hydrogeologic systems. Contaminant transport simulated with the MODFLOW Model revealed dominance of advective transport of contaminants in unconsolidated porous media. However, attenuation through sorption (linear isotherm equilibrium controlled) and reaction (first-order irreversible decay) also retarded contaminant plume migration. Thus natural attenuation was found to be highly feasible in clay formations due to low hydraulic conductivity and long groundwater residence times. Though natural attenuation processes including dispersion, diffusion, dilution, mixing, volatilization and biodegradation were not investigated for in this paper, it is shown to be a sound remediation technique of contaminated ground water due to its capacity to destroy or transform contaminants or at least retard their flow.

  2. 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.

  3. 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.

  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. Aluminum and iron doped graphene for adsorption of methylated arsenic pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Cortés-Arriagada, Diego, E-mail: dcarriagada@gmail.com; Toro-Labbé, Alejandro

    2016-11-15

    Graphical abstract: Quantum chemistry calculations show the ability of aluminum and iron doped graphene for the removal of methylated arsenicals in their trivalent and pentavalent states, with adsorption energies on the range of 1.5–4.2 eV, and high stability in a water environment. Display Omitted - Highlights: • Al and Fe-doped graphene serve as superior materials for adsorption of methylated arsenicals, including thioarsenicals. • Pentavalent arsenicals are adsorbed with higher adsorption energies (up to 4.2 eV) than trivalent arsenicals (up to 1.7 eV). • The adsorption strength is determined by the weakening of the interacting σAs−O bond in the pollutant. • The adsorption stability was studied in a water environment and molecular dynamics calculations were performed at 300 K. • Trivalent and petavalent forms are mainly adsorbed at neutral pH in their neutral and anionic forms, respectively. - Abstract: The ability of Al and Fe-doped graphene for the adsorption of trivalent and pentavalent methylated arsenic compounds was studied by quantum chemistry computations. The adsorption of trivalent methylarsenicals is reached with adsorption energies of 1.5–1.7 eV at neutral conditions; while, adsorption of pentavalent methylarsenicals reaches adsorption energies of 3.3–4.2 eV and 1.2–2.4 eV from neutral to low pH conditions, respectively. Moreover, the weakening of the interacting σAs−O bond in the pollutant structure played an important role in the stability of the adsorbent–adsorbate systems, determining the adsorption strength. In addition, the pollutant adsorption appears to be efficient in aqueous environments, with even high stability at ambient temperature; in this regard, it was determined that the trivalent and petavalent forms are mainly adsorbed in their neutral and anionic forms at neutral pH, respectively. Therefore, Al and Fe-doped graphene are considered as potential future materials for the removal of methylated arsenic

  6. 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.

  7. 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.

  8. 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).

  9. 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.

  10. ASPECTS CONCERNING NITRATE AND NITRITE POLLUTION OF GROUNDWATERS

    Directory of Open Access Journals (Sweden)

    A. UNGUREANU

    2011-03-01

    Full Text Available Aspects concerning nitrate and nitrite pollution of groundwaters. Water is a basic natural resource for the good functioning of all thebiological processes in nature. It is very important for life and for the developmentof human activities. The quality of the ground water has begun to degrade moreand more, as a result of the physical, chemical and bacteriological changes.Nitrogen compounds pollution of the underground has increased lately. This hasbeen caused by the excessive and irrational use of nitrogen derived fertilizers, bythe wrong storage of the dejections resulted from zootechnical processes and byother chemical substances discharged into water. Samples were collected fromdifferent wells in order to check whether the well water was drinkable. The resultof the test revealed the existence of high concentrations of nitrates as well asvalues exceeding normal microbiological parameters. The value recorded in thetown of Segarcea, the county of Dolj, showed extremely high concentrations ofnitrates of the drinking water in the wells. Thus, Segarcea is the town with thegreatest number of contaminated wells in the country.

  11. 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

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

    Science.gov (United States)

    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

  13. Using GA-Ridge regression to select hydro-geological parameters influencing groundwater pollution vulnerability.

    Science.gov (United States)

    Ahn, Jae Joon; Kim, Young Min; Yoo, Keunje; Park, Joonhong; Oh, Kyong Joo

    2012-11-01

    For groundwater conservation and management, it is important to accurately assess groundwater pollution vulnerability. This study proposed an integrated model using ridge regression and a genetic algorithm (GA) to effectively select the major hydro-geological parameters influencing groundwater pollution vulnerability in an aquifer. The GA-Ridge regression method determined that depth to water, net recharge, topography, and the impact of vadose zone media were the hydro-geological parameters that influenced trichloroethene pollution vulnerability in a Korean aquifer. When using these selected hydro-geological parameters, the accuracy was improved for various statistical nonlinear and artificial intelligence (AI) techniques, such as multinomial logistic regression, decision trees, artificial neural networks, and case-based reasoning. These results provide a proof of concept that the GA-Ridge regression is effective at determining influential hydro-geological parameters for the pollution vulnerability of an aquifer, and in turn, improves the AI performance in assessing groundwater pollution vulnerability.

  14. 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.

  15. 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 ...

  16. 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

  17. Retting of jute grown in arsenic contaminated area and consequent arsenic pollution in surface water bodies.

    Science.gov (United States)

    Majumder, Aparajita; Bairagya, M D; Basu, B; Gupta, P C; Sarkar, S

    2013-01-01

    Arsenic (As) toxicity of ground water in Bengal delta is a major environmental catastrophe. Cultivation of jute, a non edible crop after summer rice usually reduces arsenic load of the soil. However, during retting of jute As is present in the crop and thus increase its amount in surface water bodies. To test this hypothesis, a study was carried out in ten farmers' field located in As affected areas of West Bengal, India. As content of soil and variou the jute plant were recorded on 35 and 70 days after sowing (DAS) as well as on harvest date (110 DAS). During the study period, due to the influence of rainfall, As content of surface (0-150 mm) soil fluctuates in a narrow range. As content of jute root was in the range of 1.13 to 9.36 mg kg(-1). As content of both root and leaf attained highest concentration on 35 DAS and continuously decreased with the increase in crop age. However, in case of shoot, the As content initially decreased by 16 to 50% during 35 to 70 DAS and on 110 DAS the value slightly increased over 70 DAS. Retting of jute in pond water increased the water As content by 0.2 to 2.0 mg L(-1). The increment was 1.1 to 4 times higher over the WHO safe limit (0.05 mg L(-1)) for India and Bangladesh. Microbiological assessment in this study reveals the total bacterial population of pre and post retting pond water. Bacterial strains capable in transforming more toxic As-III to less toxic AS-V were screened and six of them were selected based on their As tolerance capacity. Importantly, identified bacterial strain Bacterium C-TJ19 (HQ834294) has As transforming ability as well as pectinolytic activity, which improves fibre quality of jute. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. A STUDY ON THE EVOLUTION OF GROUNDWATER POLLUTANTS AND CAUSES OF FORMATION IN MANZHOULI

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Studying the evolution of groundwater pollutants and the causes of formation in Manzhouli is important and necessitous as the present water source of the production and living in Manzhouli is just groundwater and the water crisis is staring Manzhouli people in the face. The evolution of pollutants in groundwater in Manzhouli was derived based on the continuously monitoring between 1989 and 1999. In total, the quality of groundwater in Manzhouli is good except that the content of F is exceeding the standard. The quality of groundwater varies seasonally. The content of pollutants in high water is higher than in the low water except pH and As. The yearly evolution shows the regime like the damp surge. The evolution of pH is inverse to NO3-N and F after 1999. The courses of formation of the evolution of the content of the pollutants in groundwater in Manzhouli are the supply of runoff, the feature of rock, the time the water being stayed in the layers and the chemical field. Being affected by the supply of ground surface and hydrogeology condition, the contents of pollutant are higher in the May than in September and the yearly evolution is undulance. In total, the pollutants in the deeper layers are less than in the upper layers. Explosion water in the deeper layers, using the techniques of cutting F and minifying the pollutants caused by human being are the sound countermeasures in Manzhouli.

  19. Strategies for the engineered phytoremediation of toxic element pollution: mercury and arsenic.

    Science.gov (United States)

    Meagher, Richard B; Heaton, Andrew C P

    2005-12-01

    Plants have many natural properties that make them ideally suited to clean up polluted soil, water, and air, in a process called phytoremediation. We are in the early stages of testing genetic engineering-based phytoremediation strategies for elemental pollutants like mercury and arsenic using the model plant Arabidopsis. The long-term goal is to develop and test vigorous, field-adapted plant species that can prevent elemental pollutants from entering the food-chain by extracting them to aboveground tissues, where they can be managed. To achieve this goal for arsenic and mercury, and pave the way for the remediation of other challenging elemental pollutants like lead or radionucleides, research and development on native hyperaccumulators and engineered model plants needs to proceed in at least eight focus areas: (1) Plant tolerance to toxic elementals is essential if plant roots are to penetrate and extract pollutants efficiently from heterogeneous contaminated soils. Only the roots of mercury- and arsenic-tolerant plants efficiently contact substrates heavily contaminated with these elements. (2) Plants alter their rhizosphere by secreting various enzymes and small molecules, and by adjusting pH in order to enhance extraction of both essential nutrients and toxic elements. Acidification favors greater mobility and uptake of mercury and arsenic. (3) Short distance transport systems for nutrients in roots and root hairs requires numerous endogenous transporters. It is likely that root plasma membrane transporters for iron, copper, zinc, and phosphate take up ionic mercuric ions and arsenate. (4) The electrochemical state and chemical speciation of elemental pollutants can enhance their mobility from roots up to shoots. Initial data suggest that elemental and ionic mercury and the oxyanion arsenate will be the most mobile species of these two toxic elements. (5) The long-distance transport of nutrients requires efficient xylem loading in roots, movement through the

  20. 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.

  1. 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.

  2. Optimising a monitoring network for groundwater pollution using stochastic simulation and a cost model

    NARCIS (Netherlands)

    Bierkens, M.F.P.

    2002-01-01

    The goal is to detect pollution at industrial sites at some distance from the site's boundary so that it can be cleaned up or hydrologically contained before contaminating groundwater outside the site

  3. 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

  4. Solubility enhancement effect of cyclodexin on groundwater pollutants.

    Science.gov (United States)

    Gao, Heng; Blanford, William J; Gao, Aifang

    2013-03-01

    Cyclodextrin (CD) molecules are polycyclic glucose oligomers that have a hydrophilic exterior and a hydrophobic cavity. This structure provides CD the characteristic of enhancing the solubility of groundwater pollutants. The degree to which CD increases the apparent aqueous solubility of certain chemicals has been defined as the solubility enhancement factor (SEF). In this study, a novel and experimentally simple method has been developed to determine the SEF, which can be mathematically obtained by ratio of apparent and traditional Henry's law constants. The effects of temperature and CD concentration on the SEFs and CD cavity occupation have been investigated. Our results show that SEF values are inversely related to temperature for most examined chemicals, which is consistent with the assertion that the CD-chemical complexes are less stable at higher temperatures. The exception is toluene that shows the least SEF fluctuation within the temperature range studied (5 to 65 °C). This may indicate that the toluene-CD complex is particularly stable. As the definition of SEF predicted, linear relationships were found between the SEFs and CD concentrations for all the subject chemicals. The CD cavity occupation fraction at 5 °C were 3.14, 2.55, 2.04, 1.60, and 1.67 times greater than the values at 65 °C for of trichloroethylene, perchloroethylene, bezene, ethylbenze, and o-xylene, respectively. The fraction of CD cavities occupied was found to be inversely related to the CD concentration for all tested chemicals when pollutant mass are held constant. This study provides important information to accurately evaluate the performance of CD when used for aquifer remediation.

  5. 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

  6. Evaluation of pollution status of heavy metals in the groundwater ...

    African Journals Online (AJOL)

    IKENNA

    manganese (Mn), lead (pb) and arsenic (As) as major contaminants in the Abakaliki dumpsites has been established in ... reduce the aesthetic values of the environment, cause nuisance and ... of the toxic compounds into surface water and.

  7. Characterization of an old municipal landfill (Grindsted, Denmark) as a groundwater pollution source

    DEFF Research Database (Denmark)

    Kjeldsen, Peter; Grundtvig, Aase; Winther, Pia

    1998-01-01

    Investigations into the pollution of groundwater from old landfill have, in most cases, focused on delineating the pollution plume rather than on the landfill as a source of groundwater pollution. Landfills often cover large areas and spatial variations in leachate composition within the landfill...... variations in leachate composition are very important for locating the main source of the groundwater pollution and for selection of cost-effective remedial action activities....... may have great impact on the location of the main pollution plume in the downstream aquifer. The history of the Grindsted Landfill in Denmark was investigated using aerial photographs and interviews. On the basis of the aerial photographs, waste volume and age of the different areas of the landfill...

  8. Changes of Groundwater Quality in the Sorrounding Pollution Sources Due to Earthquake Dissaster

    Directory of Open Access Journals (Sweden)

    Sudarmadji Sudarmadji

    2016-05-01

    Full Text Available Groundwater is the main domestic water supply of the population of the Yogyakarta Special Region, both in the urban and as well as in the rural area due to its quantity and quality advantages. The rapid population growth has caused an increase of groundwater demand, consequently it is facing some problems to the sustainability of groundwater supply. Lowering of groundwater level has been observed in some places, as well as the degradation of groundwater quality. Earthquake which stroke Yogyakarta on 27 May 2006, damaged buildings and other infrastructures in the area, including roads and bridges. It might also damage the underground structures such as septic tanks, and pipes underneath the earth surface. It might cause cracking of the geologic structures. Furthermore, the damage of underneath infrastructures might create groundwater quality changes in the area. Some complains of local community on lowering and increasing groundwater level and groundwater quality changes were noted. Field observation and investigation were conducted, including collection of groundwater samples close to (the pollution sources. Laboratory analyses indicated that some parameters increased to exceed the drinking water quality standards. The high content of Coli form bacteria possibly was caused by contamination of nearby septic tanks or other pollution sources to the observed groundwater in the dug well.

  9. Aluminum and iron doped graphene for adsorption of methylated arsenic pollutants

    Science.gov (United States)

    Cortés-Arriagada, Diego; Toro-Labbé, Alejandro

    2016-11-01

    The ability of Al and Fe-doped graphene for the adsorption of trivalent and pentavalent methylated arsenic compounds was studied by quantum chemistry computations. The adsorption of trivalent methylarsenicals is reached with adsorption energies of 1.5-1.7 eV at neutral conditions; while, adsorption of pentavalent methylarsenicals reaches adsorption energies of 3.3-4.2 eV and 1.2-2.4 eV from neutral to low pH conditions, respectively. Moreover, the weakening of the interacting σAssbnd O bond in the pollutant structure played an important role in the stability of the adsorbent-adsorbate systems, determining the adsorption strength. In addition, the pollutant adsorption appears to be efficient in aqueous environments, with even high stability at ambient temperature; in this regard, it was determined that the trivalent and petavalent forms are mainly adsorbed in their neutral and anionic forms at neutral pH, respectively. Therefore, Al and Fe-doped graphene are considered as potential future materials for the removal of methylated arsenic pollutants.

  10. 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.

  11. 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

  12. Spatial analysis of health risk assessment with arsenic intake of drinking water in the LanYang plain

    Science.gov (United States)

    Chen, C. F.; Liang, C. P.; Jang, C. S.; Chen, J. S.

    2016-12-01

    Groundwater is one of the most component water resources in Lanyang plain. The groundwater of the Lanyang Plain contains arsenic levels that exceed the current Taiwan Environmental Protection Administration (Taiwan EPA) limit of 10 μg/L. The arsenic of groundwater in some areas of the Lanyang Plain pose great menace for the safe use of groundwater resources. Therefore, poor water quality can adversely impact drinking water uses, leading to human health risks. This study analyzed the potential health risk associated with the ingestion of arsenic-affected groundwater in the arseniasis-endemic Lanyang plain. Geostatistical approach is widely used in spatial variability analysis and distributions of field data with uncertainty. The estimation of spatial distribution of the arsenic contaminant in groundwater is very important in the health risk assessment. This study used indicator kriging (IK) and ordinary kriging (OK) methods to explore the spatial variability of arsenic-polluted parameters. The estimated difference between IK and OK estimates was compared. The extent of arsenic pollution was spatially determined and the Target cancer risk (TR) and dose response were explored when the ingestion of arsenic in groundwater. Thus, a zonal management plan based on safe groundwater use is formulated. The research findings can provide a plan reference of regional water resources supplies for local government administrators and developing groundwater resources in the Lanyang Plain.

  13. Explaining nitrate pollution pressure on the groundwater resource in Kinshasa using a multivariate statistical modelling approach

    Science.gov (United States)

    Mfumu Kihumba, Antoine; Vanclooster, Marnik

    2013-04-01

    Drinking water in Kinshasa, the capital of the Democratic Republic of Congo, is provided by extracting groundwater from the local aquifer, particularly in peripheral areas. The exploited groundwater body is mainly unconfined and located within a continuous detrital aquifer, primarily composed of sedimentary formations. However, the aquifer is subjected to an increasing threat of anthropogenic pollution pressure. Understanding the detailed origin of this pollution pressure is important for sustainable drinking water management in Kinshasa. The present study aims to explain the observed nitrate pollution problem, nitrate being considered as a good tracer for other pollution threats. The analysis is made in terms of physical attributes that are readily available using a statistical modelling approach. For the nitrate data, use was made of a historical groundwater quality assessment study, for which the data were re-analysed. The physical attributes are related to the topography, land use, geology and hydrogeology of the region. Prior to the statistical modelling, intrinsic and specific vulnerability for nitrate pollution was assessed. This vulnerability assessment showed that the alluvium area in the northern part of the region is the most vulnerable area. This area consists of urban land use with poor sanitation. Re-analysis of the nitrate pollution data demonstrated that the spatial variability of nitrate concentrations in the groundwater body is high, and coherent with the fragmented land use of the region and the intrinsic and specific vulnerability maps. For the statistical modeling use was made of multiple regression and regression tree analysis. The results demonstrated the significant impact of land use variables on the Kinshasa groundwater nitrate pollution and the need for a detailed delineation of groundwater capture zones around the monitoring stations. Key words: Groundwater , Isotopic, Kinshasa, Modelling, Pollution, Physico-chemical.

  14. 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.

  15. 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.

  16. Use of the landfill water pollution index (LWPI) for groundwater quality assessment near the landfill sites.

    Science.gov (United States)

    Talalaj, Izabela A; Biedka, Pawel

    2016-12-01

    The purpose of the paper is to assess the groundwater quality near the landfill sites using landfill water pollution index (LWPI). In order to investigate the scale of groundwater contamination, three landfills (E, H and S) in different stages of their operation were taken into analysis. Samples of groundwater in the vicinity of studied landfills were collected four times each year in the period from 2004 to 2014. A total of over 300 groundwater samples were analysed for pH, EC, PAH, TOC, Cr, Hg, Zn, Pb, Cd, Cu, as required by the UE legal acts for landfill monitoring system. The calculated values of the LWPI allowed the quantification of the overall water quality near the landfill sites. The obtained results indicated that the most negative impact on groundwater quality is observed near the old Landfill H. Improper location of piezometer at the Landfill S favoured infiltration of run-off from road pavement into the soil-water environment. Deep deposition of the groundwater level at Landfill S area reduced the landfill impact on the water quality. Conducted analyses revealed that the LWPI can be used for evaluation of water pollution near a landfill, for assessment of the variability of water pollution with time and for comparison of water quality from different piezometers, landfills or time periods. The applied WQI (Water Quality Index) can also be an important information tool for landfill policy makers and the public about the groundwater pollution threat from landfill.

  17. 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.

  18. 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

  19. 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

  20. Characterization of DOM in landfill leachate polluted groundwater with electrospary LC-MS

    DEFF Research Database (Denmark)

    Persson, L.; Alsberg, T.; Odham, G.

    2001-01-01

    Dissolved organic matter in leachate polluted groundwater, downgradient a landfill, was analysed with electrospray mass spectrometry. The results indicate that the DOM change qualitatively in the gradient, becoming more uniform in functional groups and hydrofobicity. Those changes may affect...... the DOM facilitated transport of pollutants....

  1. Sequential Optimal Monitoring Network Design using Iterative Kriging for Identification of Unknown Groundwater Pollution Sources Location

    Science.gov (United States)

    Prakash, O.; Datta, B.

    2011-12-01

    Identification of unknown groundwater pollution source characteristics, in terms of location, magnitude and activity duration is important for designing an effective pollution remediation strategy. Precise source characterization also becomes very important to ascertain liability, and to recover the cost of remediation from parties responsible for the groundwater pollution. Due to the uncertainties in accurately predicting the aquifer response to source flux injection, generally encountered sparsity of concentration observation data in the field, and the non uniqueness in the aquifer response to the subjected hydraulic and chemical stresses, groundwater pollution source characterization remains a challenging task. A scientifically designed pollutant concentration monitoring network becomes imperative for accurate pollutant source characterization. The efficiency of the unknown source locations identification process is largely determined by locations of monitoring wells where the pollutant concentration is observed. The proposed method combines spatial interpolation of concentration measurements and Simulated Annealing as optimization algorithm to find the optimum locations for monitoring wells. Initially, the observed concentration data at few sparsely and arbitrarily distributed wells are used to interpolate the concentration data for the aquifer study area. The concentration information is passed to the optimization algorithm (decision model) as concentration gradient which in turn finds the optimum locations for implementing the next sequence of monitoring wells. Concentration measurement data from these designed monitoring wells and already implemented monitoring network are iteratively used as feedback information for potential groundwater pollution source locations identification. The potential applicability of the developed methodology is demonstrated for an illustrative study area.

  2. 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.

  3. 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.

  4. 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

  5. Bacterial communities in tetrachloroethene-polluted groundwaters: a case study.

    Science.gov (United States)

    Kotik, Michael; Davidová, Anna; Voříšková, Jana; Baldrian, Petr

    2013-06-01

    The compositions of bacterial groundwater communities of three sites contaminated with chlorinated ethenes were analyzed by pyrosequencing their 16S rRNA genes. For each location, the entire and the active bacterial populations were characterized by independent molecular analysis of the community DNA and RNA. The sites were selected to cover a broad range of different environmental conditions and contamination levels, with tetrachloroethene (PCE) and trichloroethene (TCE) being the primary contaminants. Before sampling the biomass, a long-term monitoring of the polluted locations revealed high concentrations of cis-1,2-dichloroethene (cDCE) and vinyl chloride (VC), which are toxic by-products of the incomplete bacterial degradation of PCE and TCE. The applied pyrosequencing technique enabled known dechlorinators to be identified at a very low detection level (study revealed that only a few species dominated the bacterial communities, with Albidiferax ferrireducens being the only highly prominent member found at all three sites. Only a limited number of OTUs with abundances of up to 1% and high sequence identities to known dechlorinating microorganisms were retrieved from the RNA pools of the two highly contaminated sites. The dechlorinating consortium was likely to be comprised of cDCE-assimilating bacteria (Polaromonas spp.), anaerobic organohalide respirers (mainly Geobacter spp.), and Burkholderia spp. involved in cometabolic dechlorination processes, together with methylotrophs (Methylobacter spp.). The deep sequencing results suggest that the indigenous dechlorinating consortia present at the investigated sites can be used as a starting point for future bioremediation activities by stimulating their anaerobic and aerobic chloroethene degradation capacities (i.e. reductive dechlorination, and metabolic and cometabolic oxidation).

  6. 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.

  7. 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.

  8. An almost-parameter-free harmony search algorithm for groundwater pollution source identification.

    Science.gov (United States)

    Jiang, Simin; Zhang, Yali; Wang, Pei; Zheng, Maohui

    2013-01-01

    The spatiotemporal characterization of unknown sources of groundwater pollution is frequently encountered in environmental problems. This study adopts a simulation-optimization approach that combines a contaminant transport simulation model with a heuristic harmony search algorithm to identify unknown pollution sources. In the proposed methodology, an almost-parameter-free harmony search algorithm is developed. The performance of this methodology is evaluated on an illustrative groundwater pollution source identification problem, and the identified results indicate that the proposed almost-parameter-free harmony search algorithm-based optimization model can give satisfactory estimations, even when the irregular geometry, erroneous monitoring data, and prior information shortage of potential locations are considered.

  9. Influence of combined pollution of antimony and arsenic on culturable soil microbial populations and enzyme activities.

    Science.gov (United States)

    Wang, Qiongshan; He, Mengchang; Wang, Ying

    2011-01-01

    The effects of both combined and single pollution of antimony (Sb) and arsenic (As) in different concentrations on culturable soil microbial populations and enzyme activities were studied under laboratory conditions. Joint effects of both Sb and As were different from that of Sb or As alone. The inhibition rate of culturable soil microbial populations under Sb and As pollution followed the order: bacterial > fungi > actinomycetes. There existed antagonistic inhibiting effect on urease and acid phophatase and synergistic inhibiting effect on protease under the combined pollution of Sb (III) and As (III). Only urease appeared to be the most sensitive indicator under Sb (V) and As (V) pollution, and there existed antagonistic inhibiting effect on acid phophatase and synergistic inhibiting effect on urease and protease under Sb (V) and As (V) combined pollution at most time. In this study, we also confirmed that the trivalent states of Sb and As were more toxic to all the microbes tested and more inhibitory on microbial enzyme activities then their pentavalent counterparts. The results also suggest that not only the application rate of the two metalloids but also the chemical form of metalloids should be considered while assessing the effect of metalloid on culturable microbial populations and enzyme activities. Urease and acid phosphatase can be used as potential biomarkers to evaluate the intensity of Sb (III) and As (III) stress.

  10. 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.

  11. Arsenic-resistant bacteria associated with roots of the wild Cirsium arvense (L.) plant from an arsenic polluted soil, and screening of potential plant growth-promoting characteristics.

    Science.gov (United States)

    Cavalca, Lucia; Zanchi, Raffaella; Corsini, Anna; Colombo, Milena; Romagnoli, Cristina; Canzi, Enrica; Andreoni, Vincenza

    2010-04-01

    A rhizobacterial community, associated with the roots of wild thistle Cirsium arvense (L.) growing in an arsenic polluted soil, was studied by fluorescence in situ hybridization (FISH) analysis in conjunction with cultivation-based methods. In the bulk, rhizosphere, and rhizoplane fractions of the soil, the qualitative picture obtained by FISH analysis of the main phylogenetic bacterial groups was similar and was predominantly comprised of Alphaproteobacteria, Betaproteobacteria, and Gammaproteobacteria. The arsenic-resistant isolates belonged to 13 genera, the most abundant being those of Bacillus, Achromobacter, Brevundimonas, Microbacterium, and Ochrobactrum. Most bacteria grew in the presence of high arsenic concentrations (over 100mM arsenate and 10mM arsenite). Most strains possessed the ArsC, ArsB and ACR3 genes homologous to arsenate reductase and to the two classes of arsenite efflux pumps, respectively, peculiar to the ars operon of the arsenic detoxification system. ArsB and ACR3 were present simultaneously in highly resistant strains. An inconsistency between 16S rRNA phylogenetic affiliations and the arsenate reductase sequences of the strains was observed, indicating possible horizontal transfer of arsenic resistance genes in the soil bacterial community. Several isolates were able to reduce arsenate and to oxidise arsenite. In particular, Ancylobacter dichloromethanicum strain As3-1b possessed both characteristics, and arsenite oxidation occurred in the strain also under chemoautotrophic conditions. Some rhizobacteria produced siderophores, indole acetic acid and 1-amino-cyclopropane-1-carboxylic acid deaminase, thus possessing potential plant growth-promoting traits.

  12. 砷的污染状况及其治理对策%Pollution Status and Treatment Measures of Arsenic

    Institute of Scientific and Technical Information of China (English)

    刘宏

    2012-01-01

    To provide a theoretical basis for integrated pollution control of arsenic in the environment, an overview of arsenic toxicity, pollution status and the pollution control measures including physical , chemical and biological methods. Especially biological methods, including microbial treatment methods and plant management methods and their effective combination of joint repair is one of the arsenic pollution prevention and control countermeasures in the most effective way, microbes and plants joint repair method has good prospects and play an important role in the future arsenic pollution control.%为了对综合治理环境中砷的污染提供理论依据,从砷的毒性,砷在环境中的污染状况,砷污染治理的物理法、化学法和生物法等方面进行了概述.强调生物法,包括微生物治理方法和植物治理方法以及两者有效结合的联合修复方法是目前砷污染防治对策中最有效的方法之一,且微生物与植物的联合修复法具有很好的发展前景,对未来砷污染治理将发挥重要作用.

  13. 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.

  14. Groundwater Pollution Arising From The Disposal Of Creosote Waste

    DEFF Research Database (Denmark)

    Arvin, Erik; Flyvbjerg, J.

    1992-01-01

    Creosote-contaminated groundwater contains a complex mixture of phenols, aromatic hydrocarbons and nitrogen-, sulphur- or oxygen-containing heterocyclic, aromatic compounds. One of the most important factors that limits the spreading of these contaminants in groundwater aquifers is degradation by...

  15. On the use of coprostanol to identify source of nitrate pollution in groundwater

    Science.gov (United States)

    Nakagawa, Kei; Amano, Hiroki; Takao, Yuji; Hosono, Takahiro; Berndtsson, Ronny

    2017-07-01

    Investigation of contaminant sources is indispensable for developing effective countermeasures against nitrate (NO3-) pollution in groundwater. Known major nitrogen (N) sources are chemical fertilizers, livestock waste, and domestic wastewater. In general, scatter diagrams of δ18O and δ15N from NO3- can be used to identify these pollution sources. However, this method can be difficult to use for chemical fertilizers and livestock waste sources due to the overlap of δ18O and δ15N ranges. In this study, we propose to use coprostanol as an indicator for the source of pollution. Coprostanol can be used as a fecal contamination indicator because it is a major fecal sterol formed by the conversion of cholesterol by intestinal bacteria in the gut of higher animals. The proposed method was applied to investigate NO3- pollution sources for groundwater in Shimabara, Nagasaki, Japan. Groundwater samples were collected at 33 locations from March 2013 to November 2015. These data were used to quantify relationships between NO3-N, δ15N-NO3-, δ18O-NO3-, and coprostanol. The results show that coprostanol has a potential for source identification of nitrate pollution. For lower coprostanol concentrations (polluted group, fertilizer is likely to be the predominant source of NO3-. However, higher concentration coprostanol samples in the nitrate-polluted group can be related to pollution from livestock waste. Thus, when conventional diagrams of isotopic ratios cannot distinguish pollution sources, coprostanol may be a useful tool.

  16. Metal pollution of groundwater in the vicinity of Valiathura Sewage Farm in Kerala, south India.

    Science.gov (United States)

    Varghese, J; Jaya, D S

    2014-12-01

    A comprehensive study was conducted to evaluate metal pollution of groundwater in the vicinity of Valiathura Sewage Farm in Thiruvananthapuram district, Kerala using the Heavy Metal Pollution Index (HPI). Forty two groundwater samples were collected during the summer season (April 2010) and the concentration of metals Fe, Cu, Zn, Cd and Pb were analyzed. Results showed that groundwater was contaminated mainly with Fe, Cu and Pb. Correlation analysis revealed that the sources of metals in groundwater in the study area are the same, and it may be due to the leachates from the nearby Sewage Farm, Parvathy Puthanar canal and solid wastes dumped in the residential area. Of the groundwater samples studied, 47.62 % were medium and 2.68 % were classified in HPI high category. HPI was highest (41.79) in DW29, which was adjacent to the polluted Parvathy Puthanar canal and Sewage Farm. The present study points out that the metal pollution causes the degradation of groundwater quality around the Sewage Farm during the study period.

  17. 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

  18. Elimination de l'Arsenic pour la production d'eau potable :
    oxydation chimique et adsorption sur des substrats solides innovants

    OpenAIRE

    Lenoble, Véronique

    2003-01-01

    Arsenic is a toxic trace element occurring in natural waters in a variety of forms including soluble, particulate and organicbound,but mainly as inorganic trivalent As(III) and pentavalent As(V) oxidation states. In many parts of the world,groundwater is polluted with arsenic. This pollution can be caused by human activities (mining, pesticides...) but usually, themain source of arsenic is geogenic. Epidemiological studies have demonstrated a significant increase in the risks of cancersassoci...

  19. 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.

  20. 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...

  1. 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.

  2. Risk assessment on mixture toxicity of arsenic, zinc and copper intake from consumption of milkfish, Chanos chanos (Forsskål), cultured using contaminated groundwater in Southwest Taiwan.

    Science.gov (United States)

    Lin, Ming-Chao

    2009-07-01

    Studies on bioaccumulation of arsenic, zinc, and copper in freshwater-cultured milkfish were carried out to assess the risks on human health. The arsenic, zinc, and copper levels in milkfish showed significant positive correlations to the arsenic, zinc, and copper concentrations in pond water. The hazard index of arsenic, zinc, and copper mixture for intake of milkfish (1.75 +/- 0.65) demonstrated that intake of in this way contaminated milkfish will result in non-carcinogenic risk. The target cancer risk of arsenic for intake of the milkfish (2.74 x 10(-4) +/- 1.18 x 10(-4)) indicated that the inhabitants were exposed to arsenic pollution with carcinogenic risk.

  3. Groundwater pollution of post-mined phosphate rock in Tuojiang watershed (Sichuan, China)

    Science.gov (United States)

    changwen, ye

    2014-05-01

    Phosphate rock is the source of phosphorus used to make phosphatic fertilizers, essential for growing the food needed by humans in the world today and in the future. The erosion and eluviation on exposed phosphrite layer and overburden in the phosphate rock areas result in the releasing of fluoride and phosphorus and groundwater polluting. Meanwhile, the waste water and untreated mineral waste residue in the beneficiation and mining operations are also main source of pollution. The un-restored post-mined phosphate rock areas in Tuojiang watershed is large scale. The investigation of the amounts of pollutants releasing from mined lands and transporting by runoffs was conducted. The releasing and transporting amounts of pollutants were calculated according to the results of column leaching studies and acreages of exposed phosphrite layers and overburdens. In conclusion, phosphorus mining activity is an important non-point source of groundwater contamination of Tuojiang watershed.Study about the management and engineering measurement can be carried out according to the non-point source: agriculture, Pollution, Phosphorous mine and chemical plant. The study can provide the practical consultation and help making the decision about the management and treatment of groundwater resource in Tuojiang watershed. Keywords: Tuojiang watershed; Groundwater pollution; Losing process; Fluorine; Phosphorus

  4. On the scope and management of pesticide pollution of Swedish groundwater resources: The Scanian example.

    Science.gov (United States)

    Åkesson, Maria; Sparrenbom, Charlotte J; Dahlqvist, Peter; Fraser, Stephen J

    2015-04-01

    Twenty-three south-Swedish public supply wells were studied to assess pesticide pollution of regional groundwater resources. Relations between pesticide occurrence, hydrogeology, and land use were analyzed using Kohonen's Self-Organizing Maps approach. Pesticides are demonstrated to be substantially present in regional groundwater, with detections in 18 wells. Concentrations above the drinking water threshold are confirmed for nine wells. Observations indicate considerable urban influence, and lagged effects of past, less restricted use. Modern, oxic waters from shallow, unconfined, unconsolidated or fracture-type bedrock aquifers appear particularly vulnerable. Least affected waters appear primarily associated with deeper wells, anoxic conditions, and more confined sediment aquifers lacking urban influence. Comprehensive, standardized monitoring of pesticides in groundwater need to be implemented nationwide to enable sound assessments of pollution status and trends, and to develop sound groundwater management plans in accordance with the Water Framework Directive. Further, existing water protection areas and associated regulations need to be reassessed.

  5. 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.

  6. 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.

  7. Evaluation of Groundwater Pollution with Heavy Metals at the Oblogo No.1 Dumpsite in Accra, Ghana

    OpenAIRE

    Kodwo Beedu Keelson

    2014-01-01

    The aim of this research study was to evaluate the groundwater pollution risks from heavy metal contaminants near the de-commissioned Oblogo No.1 dumpsite using a combination of USEPA leachate estimation and migration models. The Hydraulic Evaluation of Landfill Performance (HELP) model was used to determine leachate volumes from the base of the dumpsite whereas the Industrial Waste Evaluation Model (IWEM) was used to determine contaminant concentrations at groundwater wells locat...

  8. Are Agricultural Measures for Groundwater Protection Beneficial When Compared to Purification of Polluted Groundwater?

    OpenAIRE

    Hasler, Berit; Lundhede, Thomas

    2005-01-01

    The groundwater resource, the drinking water areas and the surface water quality can be protected by measures, e.g. by reductions of pesticide and nutrient applications, conversion of arable land to grasslands or forests etc. The objective of the paper is to estimate the benefits of groundwater protection by the valuation method choice experiments. This method allows for separate estimation and comparison of the different attributes connected to groundwater protection i.e. the effects on drin...

  9. 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.

  10. 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.

  11. 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...

  12. 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

  13. 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.

  14. 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.

  15. 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...

  16. Groundwater quality assessment and pollution source apportionment in an intensely exploited region of northern China.

    Science.gov (United States)

    Zhang, Qianqian; Wang, Huiwei; Wang, Yanchao; Yang, Mingnan; Zhu, Liang

    2017-07-01

    Deterioration in groundwater quality has attracted wide social interest in China. In this study, groundwater quality was monitored during December 2014 at 115 sites in the Hutuo River alluvial-pluvial fan region of northern China. Results showed that 21.7% of NO3(-) and 51.3% of total hardness samples exceeded grade III of the national quality standards for Chinese groundwater. In addition, results of gray relationship analysis (GRA) show that 64.3, 10.4, 21.7, and 3.6% of samples were within the I, II, IV, and V grades of groundwater in the Hutuo River region, respectively. The poor water quality in the study region is due to intense anthropogenic activities as well as aquifer vulnerability to contamination. Results of principal component analysis (PCA) revealed three major factors: (1) domestic wastewater and agricultural runoff pollution (anthropogenic activities), (2) water-rock interactions (natural processes), and (3) industrial wastewater pollution (anthropogenic activities). Using PCA and absolute principal component scores-multivariate linear regression (APCS-MLR), results show that domestic wastewater and agricultural runoff are the main sources of groundwater pollution in the Hutuo River alluvial-pluvial fan area. Thus, the most appropriate methods to prevent groundwater quality degradation are to improve capacities for wastewater treatment and to optimize fertilization strategies.

  17. 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.

  18. 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

  19. 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

  20. 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.

  1. 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...

  2. Microbial leaching of toxic metals and arsenic from a heap consisting of heavily polluted soil

    Science.gov (United States)

    Groudev, Stoyan; Georgiev, Plamen; Spasova, Irena; Nicolova, Marina

    2014-05-01

    Soil heavily polluted with toxic heavy metals (mainly Cu, Zn, Cd) and arsenic was subjected to microbial cleanup in a heap specially constructed for this purpose. The heap was located on an impermeable geomembrane, had the shape of a truncated pyramid and contained about 240 tons of soil collected mainly from the horizon A. The soil was highly acidic (with an initial pH of about 3.2) and was preliminarily crushed to minus 2.5 cm particle size. The pollutants were present mainly as the relevant sulphide minerals and the soil was inhabited by different microorganisms, including some acidophilic chemolithotrophic bacteria able to oxidize sulphides and to solubilize the relevant toxic elements. The heap possessed systems for irrigation and aeration and was surrounded by ditches to collect the drainage heap effluents containing the dissolved pollutants. The treatment of the soil was carried out by means of interrupted irrigation with leach solutions containing diluted sulphuric acid (to maintain pH in the heap within the range of about 2.5 - 2.8) and ammonium and phosphate ions to maintain the microbial growth. The treatment was carried out for a period of about two years during different climatic seasons. After the end of leaching the soil was subjected to some conventional melioration procedures such as liming, grassing, moulching, addition of fertilizers and animal manure and periodic ploughing and irrigation to increase its quality to levels suitable for agricultural utilization.

  3. May arsenic pollution contribute to limiting Artemia franciscana invasion in southern Spain?

    Directory of Open Access Journals (Sweden)

    Marta I. Sánchez

    2016-02-01

    Full Text Available Limited information exists regarding the complex interactions between biological invasions, pollution, and climate change. Most studies indicate that pollution tends to favor invasive species. Here, we provide evidence that arsenic (As pollution may have a role in limiting the invasion of the exotic brine shrimp Artemia franciscana. We tested As toxicity in natural populations of Artemia parthenogenetica (a native taxon and A. franciscana from localities in southern Spain with differing degrees of As contamination. Tests were conducted both under current mean temperature conditions (25 °C, and as per a future climate scenario (i.e., an increase in mean temperature of 4 °C. Acute toxicity was estimated on the basis of the median lethal concentration (at 24 h, and chronic toxicity was evaluated by measuring Artemia survival and growth under sublethal exposures (after 26 days. At 25 °C, native A. parthenogenetica from the highly polluted Odiel and Tinto estuary was much more resistant to acute As stress (LC50-24 h, 24.67 mg L−1 than A. franciscana (15.78 mg L−1 and A. parthenogenetica from unpolluted sites (12.04 mg L−1–suggesting that local adaptation to polluted conditions may occur. At 29 °C, resistance of A. parthenogenetica from Odiel decreased significantly, and there were no statistical differences in sensitivity between the three species/populations, suggesting that climate change may enhance the probability of invasion. Resistance increased with developmental stage from nauplii to adults, and was extremely high in cysts which still hatched at As concentrations of up to 6400 mg L−1. Under sublethal chronic exposure A. franciscana performed better (survival and growth than A. parthenogenetica, and both species experienced a faster growth when exposed to As, compared with unexposed (control individuals, probably due to the hormesis. We discuss the ecological implications of our results.

  4. Comparative Analysis for Polluted Agricultural Soils with Arsenic, Lead, and Mercury in Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Yarto-Ramirez, Mario; Santos-Santos, Elvira; Gavilan-Garcia, Arturo; Castro-Diaz, Jose; Gavilan-Garcia, Irma Cruz; Rosiles, Rene; Suarez, Sara

    2004-03-31

    The use of mercury in Mexico has been associated with the mining industry of Zacatecas. This activity has polluted several areas currently used for agriculture. The main objective of this study was to investigate the heavy metal concentration (Hg, As and Pb) in soil of Guadalupe Zacatecas in order to justify a further environmental risk assessment in the site. A 2X3 km grid was used for the sampling process and 20 soil samples were taken. The analysis was developed using EPA SW 846: 3050B/6010B method for arsenic and metals and EPA SW 846: 7471A for total mercury. It was concluded that there are heavy metals in agricultural soils used for corn and bean farming. For this it is required to make an environmental risk assessment and a bioavailability study in order to determine if there's a risk for heavy metals bioaccumulation in animals or human beings or metal lixiviation to aquifers.

  5. Risk-based prioritization method for the classification of groundwater pesticide pollution from agricultural regions.

    Science.gov (United States)

    Yang, Yu; Lian, Xin-Ying; Jiang, Yong-Hai; Xi, Bei-Dou; He, Xiao-Song

    2017-06-03

    Agricultural regions are a significant source of groundwater pesticide pollution. To ensure that agricultural regions with a significantly high risk of groundwater pesticide contamination are properly managed, a risk-based ranking method related to groundwater pesticide contamination is needed. In the present paper, a risk-based prioritization method for the classification of groundwater pesticide pollution from agricultural regions was established. The method encompasses 3 phases, including indicator selection, characterization, and classification. In the risk ranking index system employed here, 17 indicators involving the physicochemical properties, environmental behavior characteristics, pesticide application methods, and inherent vulnerability of groundwater in the agricultural region were selected. The boundary of each indicator was determined using K-means cluster analysis based on a survey of a typical agricultural region and the physical and chemical properties of 300 typical pesticides. The total risk characterization was calculated by multiplying the risk value of each indicator, which could effectively avoid the subjectivity of index weight calculation and identify the main factors associated with the risk. The results indicated that the risk for groundwater pesticide contamination from agriculture in a region could be ranked into 4 classes from low to high risk. This method was applied to an agricultural region in Jiangsu Province, China, and it showed that this region had a relatively high risk for groundwater contamination from pesticides, and that the pesticide application method was the primary factor contributing to the relatively high risk. The risk ranking method was determined to be feasible, valid, and able to provide reference data related to the risk management of groundwater pesticide pollution from agricultural regions. Integr Environ Assess Manag 2017;00:000-000. © 2017 SETAC. © 2017 SETAC.

  6. 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.

  7. 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.

  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. 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.

  10. 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.

  11. Long-Term Oil Pollution and In Situ Microbial Response of Groundwater in Northwest China.

    Science.gov (United States)

    Sun, Yujiao; Lu, Sidan; Zhao, Xiaohui; Ding, Aizhong; Wang, Lei

    2017-05-01

    Potential threats exist where groundwater is polluted by high concentrations of oil compounds (980.20 mg L(-1) the highest TPHs). An abandoned petrochemical plant in Lanzhou City, where long-term petrochemical products leakage contaminated the groundwater, was used as a field site in this study. To determine the extent of pollution and find an effective solution, chemical techniques combined with molecular biological techniques were used to survey the migration and decomposition of pollutants. Moreover, Illumina Sequencing was employed to reveal the microbial changes of different sites. Light-chain alkanes (mostly C6-C9), most benzene compounds, and some polycyclic aromatic hydrocarbons (naphthalene, 2-methylnaphthalene) mainly polluted the source. C29 to C36 and chlorobenzenes (hexachlorocyclohexane) polluted the secondary polluted sites. Moreover, chloralkane (trichloroethane and dichloroethane), benzene derivatives (trimethylbenzene and butylbenzene), and PAHs (fluorene and phenanthrene) were present in the other longtime-contaminated water. The bacterial genera are closely related with the chemical matters, and different groups of microorganisms gather in the sample sites that are polluted with different kinds of oil. The biodiversity and abundance of observed species change with pollution conditions. The dominant phyla (81%) of the bacterial community structure are Proteobacteria (62.2% of the total microbes), Bacteroidetes (8.85%), Actinobacteria (6.70%), and Choloroflexi (3.03%). Pseudomonadaceae is significant in the oil-polluted source and Comamonadaceae is significant in the secondary polluted (migrated oil) sample; these two genera are natural decomposers of refractory matters. Amycolatopsis, Rhodocyclaceae, Sulfurimonas, and Sulfuricurvum are the dominant genera in the long-migrated oil-polluted samples. Bioavailability of the oil-contaminated place differs with levels of pollution and cleaning the worse-polluted sites by microbes is more difficult.

  12. Groundwater Pollution Arising From The Disposal Of Creosote Waste

    DEFF Research Database (Denmark)

    Arvin, Erik; Flyvbjerg, J.

    1992-01-01

    by subsurface micro-organisms. This paper gives an overview of the present knowledge about microbial degradation of creosote contaminants under aerobic and anaerobic conditions. Furthermore, various techniques for biological remediation of creosote-contaminated groundwater are outlined. These techniques include...

  13. Vadose Zone Monitoring as a Key to Groundwater Protection from Pollution Hazard

    Science.gov (United States)

    Dahan, Ofer

    2016-04-01

    Minimization subsurface pollution is much dependent on the capability to provide real-time information on the chemical and hydrological properties of the percolating water. Today, most monitoring programs are based on observation wells that enable data acquisitions from the saturated part of the subsurface. Unfortunately, identification of pollutants in well water is clear evidence that the contaminants already crossed the entire vadose-zone and accumulated in the aquifer water to detectable concentration. Therefore, effective monitoring programs that aim at protecting groundwater from pollution hazard should include vadose zone monitoring technologies that are capable to provide real-time information on the chemical composition of the percolating water. Obviously, identification of pollution process in the vadose zone may provide an early warning on potential risk to groundwater quality, long before contaminates reach the water-table and accumulate in the aquifers. Since productive agriculture must inherently include down leaching of excess lower quality water, understanding the mechanisms controlling transport and degradation of pollutants in the unsaturated is crucial for water resources management. A vadose-zone monitoring system (VMS), which was specially developed to enable continuous measurements of the hydrological and chemical properties of percolating water, was used to assess the impact of various agricultural setups on groundwater quality, including: (a) intensive organic and conventional greenhouses, (b) citrus orchard and open field crops , and (c) dairy farms. In these applications frequent sampling of vadose zone water for chemical and isotopic analysis along with continuous measurement of water content was used to assess the link between agricultural setups and groundwater pollution potential. Transient data on variation in water content along with solute breakthrough at multiple depths were used to calibrate flow and transport models. These models

  14. 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.

  15. Hydrochemical characterization and pollution sources identification of groundwater in Salawusu aquifer system of Ordos Basin, China.

    Science.gov (United States)

    Yang, Qingchun; Wang, Luchen; Ma, Hongyun; Yu, Kun; Martín, Jordi Delgado

    2016-09-01

    Ordos Basin is located in an arid and semi-arid region of northwestern China, which is the most important energy source bases in China. Salawusu Formation (Q3 s) is one of the most important aquifer systems of Ordos Basin, which is adjacent to Jurassic coalfield areas. A large-scale exploitation of Jurassic coal resources over ten years results in series of influences to the coal minerals, such as exposed to the oxidation process and dissolution into the groundwater due to the precipitation infiltration. Therefore, how these processes impact groundwater quality is of great concerns. In this paper, the descriptive statistical method, Piper trilinear diagram, ratios of major ions and canonical correspondence analysis are employed to investigate the hydrochemical evolution, determine the possible sources of pollution processes, and assess the controls on groundwater compositions using the monitored data in 2004 and 2014 (before and after large-scale coal mining). Results showed that long-term exploration of coal resources do not result in serious groundwater pollution. The hydrochemical types changed from HCO3(-)-CO3(2-) facies to SO4(2-)-Cl facies during 10 years. Groundwater hardness, nitrate and sulfate pollution were identified in 2014, which was most likely caused by agricultural activities. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Method for screening prevention and control measures and technologies based on groundwater pollution intensity assessment

    Energy Technology Data Exchange (ETDEWEB)

    Li, Juan, E-mail: lijuan@craes.org.cn [College of Water Sciences, Beijing Normal University, Beijing 100875 (China); Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Beijing, 100012 (China); Yang, Yang [College of Environment, Beijing Normal University, Beijing 100875 (China); Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Beijing, 100012 (China); Huan, Huan; Li, Mingxiao [Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Beijing, 100012 (China); Xi, Beidou, E-mail: xibd413@yeah.net [Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Beijing, 100012 (China); Lanzhou Jiaotong University, Lanzhou 730070 (China); Lv, Ningqing [Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Beijing, 100012 (China); Wu, Yi [Guizhou Academy of Environmental Science and Designing, Guizhou 550000 (China); Xie, Yiwen, E-mail: qin3201@126.com [School of Chemical and Environmental Engineering, Dongguan University of Technology, Dongguan, 523808 (China); Li, Xiang; Yang, Jinjin [Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Beijing, 100012 (China)

    2016-05-01

    This paper presents a system for determining the evaluation and gradation indices of groundwater pollution intensity (GPI). Considering the characteristics of the vadose zone and pollution sources, the system decides which anti-seepage measures should be implemented at the contaminated site. The pollution sources hazards (PSH) and groundwater intrinsic vulnerability (GIV) are graded by the revised Nemerow Pollution Index and an improved DRTAS model, respectively. GPI is evaluated and graded by a double-sided multi-factor coupling model, which is constructed by the matrix method. The contaminated sites are categorized as prior, ordinary, or common sites. From the GPI results, we develop guiding principles for preventing and removing pollution sources, procedural interruption and remediation, and end treatment and monitoring. Thus, we can select appropriate prevention and control technologies (PCT). To screen the technological schemes and optimize the traditional analytical hierarchy process (AHP), we adopt the technique for order preference by the similarity to ideal solution (TOPSIS) method. Our GPI approach and PCT screening are applied to three types of pollution sites: the refuse dump of a rare earth mine development project (a potential pollution source), a chromium slag dump, and a landfill (existing pollution sources). These three sites are identified as ordinary, prior, and ordinary sites, respectively. The anti-seepage materials at the refuse dump should perform as effectively as a 1.5-m-thick clay bed. The chromium slag dump should be preferentially treated by soil flushing and in situ chemical remediation. The landfill should be treated by natural attenuation technology. The proposed PCT screening approach was compared with conventional screening methods results at the three sites and proved feasible and effective. The proposed method can provide technical support for the monitoring and management of groundwater pollution in China. - Highlights: • An

  17. Risk-Based Prioritization Method for the Classification of Groundwater Pollution from Hazardous Waste Landfills.

    Science.gov (United States)

    Yang, Yu; Jiang, Yong-Hai; Lian, Xin-Ying; Xi, Bei-Dou; Ma, Zhi-Fei; Xu, Xiang-Jian; An, Da

    2016-12-01

    Hazardous waste landfill sites are a significant source of groundwater pollution. To ensure that these landfills with a significantly high risk of groundwater contamination are properly managed, a risk-based ranking method related to groundwater contamination is needed. In this research, a risk-based prioritization method for the classification of groundwater pollution from hazardous waste landfills was established. The method encompasses five phases, including risk pre-screening, indicator selection, characterization, classification and, lastly, validation. In the risk ranking index system employed here, 14 indicators involving hazardous waste landfills and migration in the vadose zone as well as aquifer were selected. The boundary of each indicator was determined by K-means cluster analysis and the weight of each indicator was calculated by principal component analysis. These methods were applied to 37 hazardous waste landfills in China. The result showed that the risk for groundwater contamination from hazardous waste landfills could be ranked into three classes from low to high risk. In all, 62.2 % of the hazardous waste landfill sites were classified in the low and medium risk classes. The process simulation method and standardized anomalies were used to validate the result of risk ranking; the results were consistent with the simulated results related to the characteristics of contamination. The risk ranking method was feasible, valid and can provide reference data related to risk management for groundwater contamination at hazardous waste landfill sites.

  18. Risk-Based Prioritization Method for the Classification of Groundwater Pollution from Hazardous Waste Landfills

    Science.gov (United States)

    Yang, Yu; Jiang, Yong-Hai; lian, Xin-Ying; Xi, Bei-Dou; Ma, Zhi-fei; Xu, Xiang-Jian; An, Da

    2016-12-01

    Hazardous waste landfill sites are a significant source of groundwater pollution. To ensure that these landfills with a significantly high risk of groundwater contamination are properly managed, a risk-based ranking method related to groundwater contamination is needed. In this research, a risk-based prioritization method for the classification of groundwater pollution from hazardous waste landfills was established. The method encompasses five phases, including risk pre-screening, indicator selection, characterization, classification and, lastly, validation. In the risk ranking index system employed here, 14 indicators involving hazardous waste landfills and migration in the vadose zone as well as aquifer were selected. The boundary of each indicator was determined by K-means cluster analysis and the weight of each indicator was calculated by principal component analysis. These methods were applied to 37 hazardous waste landfills in China. The result showed that the risk for groundwater contamination from hazardous waste landfills could be ranked into three classes from low to high risk. In all, 62.2 % of the hazardous waste landfill sites were classified in the low and medium risk classes. The process simulation method and standardized anomalies were used to validate the result of risk ranking; the results were consistent with the simulated results related to the characteristics of contamination. The risk ranking method was feasible, valid and can provide reference data related to risk management for groundwater contamination at hazardous waste landfill sites.

  19. Trace metals pollution in seawater and groundwater in the ship breaking area of Sitakund Upazilla, Chittagong, Bangladesh.

    Science.gov (United States)

    Hasan, Asma Binta; Kabir, Sohail; Selim Reza, A H M; Zaman, Mohammad Nazim; Ahsan, Mohammad Aminul; Akbor, Mohammad Ahedul; Rashid, Mohammad Mamunur

    2013-06-15

    This study reveals potential accumulation of trace metals in the sea and groundwater due to ship breaking activities which take place along the Bay of Bengal in Sitakund Upazilla, Chittagong, Bangladesh. When compared with WHO and Bangladesh domestic standards for water quality, it is revealed that seawater was strongly polluted by Fe and Hg, moderately by Mn and Al, and slightly by Pb and Cd. Groundwater was strongly polluted by Fe, Pb and Hg, moderately by Mn and Al, and slightly by As. Trace element concentrations of all seawater samples exceeded the average concentration of elements in the Earth's seawater. The application of Principal Components Analysis identified two sources of pollution-marine and ship breaking. The mechanism of groundwater pollution inferred that if seawater is polluted, nearby groundwater is also polluted with trace metals due to the influence of seawater intrusion. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. 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.

  1. Groundwater pollution potential and greenhouse gas emission from soils amended with different swine biochars

    Science.gov (United States)

    Although there exist numerous research studies in the literature on greenhouse gas emission and groundwater pollution potentials of soils amended with plant-based biochar made from traditional dry pyrolysis (hereafter referred as pyrochar), a very few such studies exist for hydrochar made from hydro...

  2. Greenhouse gas emission and groundwater pollution potentials of soils amended with different swine biochars

    Science.gov (United States)

    The objective of this research was to study the greenhouse gas emission and groundwater pollution potentials of the soils amended with various biochars using different biomass feedstocks and thermal processing conditions. Triplicate sets of small pots were designed; control soil consisting of Histi...

  3. Greenhouse gas emission and groundwater pollution potentials of soils amended with raw and carbonized swine solids

    Science.gov (United States)

    The objective of this research is to study the greenhouse gas emission and groundwater pollution potentials of the soils amended with raw swine solids and swine biochars made from different thermochemical conditions. Triplicate sets of small pots were designed: 1) control soil with a 50/50 mixture o...

  4. ELECTROCHEMICAL DEGRADATION OF PERSISTANCE POLLUTANTS IN GROUNDWATER AND SEDIMENTS

    Science.gov (United States)

    Electrochemical Degradation (ECD) utilizes redox potential at the anode and the cathode to oxidize and/or reduce organic contaminants. ECD of environmentally persistence pollutants such chlorinate solvents, PCBs, and PAHs, although theoretically possible, has not been experimenta...

  5. 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.

  6. Method for screening prevention and control measures and technologies based on groundwater pollution intensity assessment.

    Science.gov (United States)

    Li, Juan; Yang, Yang; Huan, Huan; Li, Mingxiao; Xi, Beidou; Lv, Ningqing; Wu, Yi; Xie, Yiwen; Li, Xiang; Yang, Jinjin

    2016-05-01

    This paper presents a system for determining the evaluation and gradation indices of groundwater pollution intensity (GPI). Considering the characteristics of the vadose zone and pollution sources, the system decides which anti-seepage measures should be implemented at the contaminated site. The pollution sources hazards (PSH) and groundwater intrinsic vulnerability (GIV) are graded by the revised Nemerow Pollution Index and an improved DRTAS model, respectively. GPI is evaluated and graded by a double-sided multi-factor coupling model, which is constructed by the matrix method. The contaminated sites are categorized as prior, ordinary, or common sites. From the GPI results, we develop guiding principles for preventing and removing pollution sources, procedural interruption and remediation, and end treatment and monitoring. Thus, we can select appropriate prevention and control technologies (PCT). To screen the technological schemes and optimize the traditional analytical hierarchy process (AHP), we adopt the technique for order preference by the similarity to ideal solution (TOPSIS) method. Our GPI approach and PCT screening are applied to three types of pollution sites: the refuse dump of a rare earth mine development project (a potential pollution source), a chromium slag dump, and a landfill (existing pollution sources). These three sites are identified as ordinary, prior, and ordinary sites, respectively. The anti-seepage materials at the refuse dump should perform as effectively as a 1.5-m-thick clay bed. The chromium slag dump should be preferentially treated by soil flushing and in situ chemical remediation. The landfill should be treated by natural attenuation technology. The proposed PCT screening approach was compared with conventional screening methods results at the three sites and proved feasible and effective. The proposed method can provide technical support for the monitoring and management of groundwater pollution in China. Copyright © 2015

  7. 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

  8. Assessing the pollution risk of a groundwater source field at western Laizhou Bay under seawater intrusion.

    Science.gov (United States)

    Zeng, Xiankui; Wu, Jichun; Wang, Dong; Zhu, Xiaobin

    2016-07-01

    Coastal areas have great significance for human living, economy and society development in the world. With the rapid increase of pressures from human activities and climate change, the safety of groundwater resource is under the threat of seawater intrusion in coastal areas. The area of Laizhou Bay is one of the most serious seawater intruded areas in China, since seawater intrusion phenomenon was firstly recognized in the middle of 1970s. This study assessed the pollution risk of a groundwater source filed of western Laizhou Bay area by inferring the probability distribution of groundwater Cl(-) concentration. The numerical model of seawater intrusion process is built by using SEAWAT4. The parameter uncertainty of this model is evaluated by Markov Chain Monte Carlo (MCMC) simulation, and DREAM(ZS) is used as sampling algorithm. Then, the predictive distribution of Cl(-) concentration at groundwater source field is inferred by using the samples of model parameters obtained from MCMC. After that, the pollution risk of groundwater source filed is assessed by the predictive quantiles of Cl(-) concentration. The results of model calibration and verification demonstrate that the DREAM(ZS) based MCMC is efficient and reliable to estimate model parameters under current observation. Under the condition of 95% confidence level, the groundwater source point will not be polluted by seawater intrusion in future five years (2015-2019). In addition, the 2.5% and 97.5% predictive quantiles show that the Cl(-) concentration of groundwater source field always vary between 175mg/l and 200mg/l. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. 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.

  10. 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.

  11. Multimedia Environmental Pollutant Assessment System (MEPAS{reg_sign}): Groundwater pathway formulations

    Energy Technology Data Exchange (ETDEWEB)

    Whelan, G.; McDonald, J.P. [Pacific Northwest National Lab., Richland, WA (United States); Sato, C. [Idaho State Univ., Pocatello, ID (United States)

    1996-06-01

    This report describes the mathematical formulations used for contaminant fate and transport in the groundwater pathway of the Multimedia Environmental Pollutant Assessment System (MEPAS). It is one in a series of reports that collectively describe the components of MEPAS. The groundwater component of the MEPAS methodology models solute transport through the groundwater environment (i.e., partially saturated and saturated zones). Specifically, this component provides estimates of groundwater contaminant fluxes at various transporting medium interfaces (e.g., water table or aquifer/river interface) and contaminant concentrations at withdrawal wells. Contaminant fluxes at transporting medium interfaces represent boundary conditions for the next medium in which contaminant migration and fate is to be simulated (e.g., groundwater contamination entering a surface-water environment). Contaminant concentrations at withdrawal wells provide contaminant levels for the exposure assessment component of MEPAS. A schematic diagram illustrating the groundwater environment is presented. The migration and fate of contaminants through the groundwater environment are described by the three-dimensional, advective-dispersive equation for solute transport. The results are based on semianalytical solutions (i.e., solutions that require numerical integration) that are well established in the scientific literature. To increase computational efficiency, limits of integration are also identified.

  12. Saline water pollution in groundwater: issues and its control

    Directory of Open Access Journals (Sweden)

    Setyawan Purnama

    2012-10-01

    Full Text Available Nowadays, saline water pollution has been gaining its importance as the major issue around the world, especially in the urban coastal area. Saline water pollution has major impact on human life and livelihood. It´s mainly a result from static fossil water and the dynamics of sea water intrusion.. The problem of saline water pollution caused by seawater intrusion has been increasing since the beginning of urban population. The problem of sea water intrusion in the urban coastal area must be anticipated as soon as possible especially in the urban areas developed in coastal zones,. This review article aims to; (i analyze the distribution of saline water pollution on urban coastal area in Indonesia and (ii analyze some methods in controlling saline water pollution, especially due to seawater intrusion in urban coastal area. The strength and weakness of each method have been compared, including (a applying different pumping patterns, (b artificial recharge, (c extraction barrier, (d injection barrier and (e subsurface barrier. The best method has been selected considering its possible development in coastal areas of developing countries. The review is based considering the location of Semarang coastal area, Indonesia. The results have shown that artificial recharge and extraction barrier are the most suitable methods to be applied in the area.

  13. Assessment of Heavy Metal Pollution in the Groundwater of the Northern Develi Closed Basin, Kayseri, Turkey.

    Science.gov (United States)

    Arslan, Şebnem; Yücel, Çiğdem; Çallı, Süleyman Selim; Çelik, Mehmet

    2017-08-01

    This study was carried out to assess the groundwater pollution in the northern Develi Closed Basin by using the heavy metal pollution index (HPI). Samples from 10 wells and 5 springs were collected in dry and wet seasons and concentrations of Pb, Zn, Cr, Mn, Fe, Cu, Cd, As and B were determined. In both seasons, for more than half of the samples, As, B and Fe concentrations exceeded the Turkish drinking water guideline values. Due to the occurrence of these metals in high concentrations in some samples HPI values are up to 1740. The source of these metals is geogenic and attributed to the interaction of these waters with highly altered volcanic and pyroclastic rocks. The overall HPI for wet and dry periods are reported as 360 and 440, respectively. Accordingly, the pollution level in the groundwater of this area is unacceptable.

  14. Groundwater pollution risk mapping for the Eocene aquifer of the Oum Er-Rabia basin, Morocco

    Science.gov (United States)

    Ettazarini, Said

    2006-11-01

    Sustainable development requires the management and preservation of water resources indispensable for all human activities. When groundwater constitutes the main water resource, vulnerability maps therefore are an important tool for identifying zones of high pollution risk and taking preventive measures in potential pollution sites. The vulnerability assessment for the Eocene aquifer in the Moroccan basin of Oum Er-Rabia is based on the DRASTIC method that uses seven parameters summarizing climatic, geological, and hydrogeological conditions controlling the seepage of pollutant substances to groundwater. Vulnerability maps were produced by using GIS techniques and applying the “generic” and “agricultural” models according to the DRASTIC charter. Resulting maps revealed that the aquifer is highly vulnerable in the western part of the basin and areas being under high contamination risk are more extensive when the “agricultural” model was applied.

  15. Assessing the vulnerability of groundwater to pollution in Ireland based on the COST-620 Pan-European approach.

    Science.gov (United States)

    Pavlis, Michail; Cummins, Enda

    2014-01-15

    The aim of the analysis was to assess the intrinsic and specific vulnerability of groundwater to pollution from pesticides in Ireland at the national scale. A methodology to incorporate the effect of groundwater recharge in vulnerability assessment is described which can be particularly useful for the evaluation of dilution of groundwater pollutants. A sensitivity analysis using Monte-Carlo simulation revealed that the most important parameters of the model were subsoil (ρ = 0.79) and topsoil (ρ = 0.72), which is in agreement with the current knowledge of the parameters that have a significant effect on groundwater vulnerability in Ireland. The intrinsic vulnerability assessment was verified using total organic carbon (TOC) concentration in groundwater, a novel approach for the validation of groundwater vulnerability methods at regional scales. A statistical analysis showed that TOC concentration was significantly different (p groundwater vulnerability. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Efficient artificial mineralization route to decontaminate Arsenic(III) polluted water - the Tooeleite Way

    Science.gov (United States)

    Malakar, Arindam; Das, Bidisa; Islam, Samirul; Meneghini, Carlo; de Giudici, Giovanni; Merlini, Marco; Kolen'Ko, Yury V.; Iadecola, Antonella; Aquilanti, Giuliana; Acharya, Somobrata; Ray, Sugata

    2016-05-01

    Increasing exposure to arsenic (As) contaminated ground water is a great threat to humanity. Suitable technology for As immobilization and removal from water, especially for As(III) than As(V), is not available yet. However, it is known that As(III) is more toxic than As(V) and most groundwater aquifers, particularly the Gangetic basin in India, is alarmingly contaminated with it. In search of a viable solution here, we took a cue from the natural mineralization of Tooeleite, a mineral containing Fe(III) and As(III)ions, grown under acidic condition, in presence of SO42- ions. Complying to this natural process, we could grow and separate Tooeleite-like templates from Fe(III) and As(III) containing water at overall circumneutral pH and in absence of SO42- ions by using highly polar Zn-only ends of wurtzite ZnS nanorods as insoluble nano-acidic-surfaces. The central idea here is to exploit these insoluble nano-acidic-surfaces (called as INAS in the manuscript) as nucleation centres for Tooeleite growth while keeping the overall pH of the aqueous media neutral. Therefore, we propose a novel method of artificial mineralization of As(III) by mimicking a natural process at nanoscale.

  17. Efficient artificial mineralization route to decontaminate Arsenic(III) polluted water - the Tooeleite Way.

    Science.gov (United States)

    Malakar, Arindam; Das, Bidisa; Islam, Samirul; Meneghini, Carlo; De Giudici, Giovanni; Merlini, Marco; Kolen'ko, Yury V; Iadecola, Antonella; Aquilanti, Giuliana; Acharya, Somobrata; Ray, Sugata

    2016-05-18

    Increasing exposure to arsenic (As) contaminated ground water is a great threat to humanity. Suitable technology for As immobilization and removal from water, especially for As(III) than As(V), is not available yet. However, it is known that As(III) is more toxic than As(V) and most groundwater aquifers, particularly the Gangetic basin in India, is alarmingly contaminated with it. In search of a viable solution here, we took a cue from the natural mineralization of Tooeleite, a mineral containing Fe(III) and As(III)ions, grown under acidic condition, in presence of SO4(2-) ions. Complying to this natural process, we could grow and separate Tooeleite-like templates from Fe(III) and As(III) containing water at overall circumneutral pH and in absence of SO4(2-) ions by using highly polar Zn-only ends of wurtzite ZnS nanorods as insoluble nano-acidic-surfaces. The central idea here is to exploit these insoluble nano-acidic-surfaces (called as INAS in the manuscript) as nucleation centres for Tooeleite growth while keeping the overall pH of the aqueous media neutral. Therefore, we propose a novel method of artificial mineralization of As(III) by mimicking a natural process at nanoscale.

  18. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  20. 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

  1. 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.

  2. 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

  3. 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

  4. Evaluation of groundwater pollution risk (GPR) from agricultural activities using DRASTIC model and GIS

    Science.gov (United States)

    Mohd Ariffin, Sabrina; Zawawi, Mohamed Azwan Mohamed; Che Man, Hasfalina

    2016-06-01

    Groundwater Pollution risk (GPR) map which utilized groundwater quality is important in order to prevent the groundwater contaminant concentration due to the agricultural activities. DRASTIC model and GIS application are two important tools that had been used for accessing and predicting the quality of groundwater. These supplementary tools are calculating, visualizing, and presenting the GPR by using DRASTIC index for each hydrogeologic factor through ArcGIS software. This study was covered approximately Selangor basin area where the GPR has been defined. There are four categories of agricultural activities in the Selangor basin which are animal husbandary areas, horticultural lands, short term crops and tree, palm and other permanent crops. The map showed that the “low” zones of GPR occupied 56% of the east side of the Selangor basin, 34% of the west side of the Selangor basin exposed to “medium” zones of GPR and the “high” zones of GPR covered 10% at the north side and the south to the west side of the Selangor basin. As a particular, for agricultural activities which is 52% of Selangor basin area, the “low”, ‘’medium” and “high” zones of GPR was occupied as 42%, 43% and 15% respectively. Based on four categories of agricultural landuse, GPR map validated by nitrate distribution map, shows that the 99% of the variation in nitrate distribution zones are explained by GPR zones. In conclusion, groundwater pollution risk was affected by agricultural activities.

  5. 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.

  6. Multi-Scale Monitoring and Assessment of Nonpoint Source Pollution in Groundwater

    Science.gov (United States)

    Harter, T.; Vanderschans, M.; Leijnse, A.; Mathews, M. C.; Meyer, R. D.

    2003-04-01

    The California dairy industry produces 20% of US milk and is the largest animal industry in the state. Many of the dairy facilities are located in low-relief valleys and basins with vulnerable groundwater resources. The continued influx of dairies into California's Central Valley has raised critical questions regarding their environmental performance, in particular with respect to groundwater quality impacts. While animal farming systems are considered among the leading sources of groundwater nitrate,little is known about the actual impact of dairy farming practices on groundwater quality in the extensive alluvial aquifers underlying the Central Valley. With our work we attempt to characterize and assess shallow groundwater underneath dairies in a relatively vulnerable hydrogeologic region and to discern the impact from various individual sources and management practices within dairies. An extensive shallow groundwater monitoring network was installed on five representative dairy operations in the northeastern San Joaquin Valley, California. The monitoring network spans all dairy management units: manure water lagoons, corrals, storage areas, and manure treated forage fields under various management practices. We recently also surveyed production well water quality. Water quality is found to be highly variable, both in time and space. We propose that a meaningful interpretation of these (nonpoint source pollution) data is only possible by explicitly considering the various scales affiliated with groundwater measurement, pollution source management, regulatory control, and beneficial use. Using statistical analysis and innovative modeling tools, we provide an interpretation of the observed data that is meaningful at the field scale (the scale unit of management decisions), the farm scale (considered to be a regulatory and planning unit), and the regional scale (considered to be a planning unit).

  7. Got Milk? Got Water? Innovative Approach to Evaluating Groundwater Nitrate Nonpoint Source Pollution from Animal Farming

    Science.gov (United States)

    Harter, T.; Vanderschans, M.; Leijnse, A.; Meyer, R. D.; Mathews, M. C.

    2002-12-01

    The California dairy industry produces 20% of US milk and is the largest animal industry in the state. Many of the dairy facilities are located in low-relief valleys and basins with vulnerable groundwater resources. The continued influx of dairies into California's Central Valley has raised critical questions regarding their environmental performance, in particular with respect to groundwater quality impacts. While animal farming systems are considered among the leading sources of groundwater nitrate,little is known about the actual impact of dairy farming practices on groundwater quality in the extensive alluvial aquifers underlying the Central Valley. With our work we attempt to characterize and assess shallow groundwater underneath dairies in a relatively vulnerable hydrogeologic region and to discern the impact from various individual sources and management practices within dairies. An extensive shallow groundwater monitoring network was installed on five representative dairy operations in the northeastern San Joaquin Valley, California. The monitoring network spans all dairy management units: manure water lagoons, corrals, storage areas, and manure treated forage fields under various management practices. We recently also surveyed production well water quality. Water quality is found to be highly variable, both in time and space. We propose that a meaningful interpretation of these (nonpoint source pollution) data is only possible by explicitly considering the various scales affiliated with groundwater measurement, pollution source management, regulatory control, and beneficial use. Using statistical analysis and innovative modeling tools, we provide an interpretation of the observed data that is meaningful at the field scale (the scale unit of management decisions), the farm scale (considered to be a regulatory and planning unit), and the regional scale (considered to be a planning unit).

  8. The Impact of Some Economic Factors Affecting Groundwater Pollution in Both Developed and Developing Countries

    Directory of Open Access Journals (Sweden)

    H. Biabi

    2016-03-01

    Full Text Available Introduction: The role of economic factors in pollution and environmental degradation is one of the major Issues in economic and environmental studies that many researchers have addressed in their studies. One of the issues in the field of environment to which less attention has been paid is the effect of economic factors such as the openness of the economy on water resource pollution. In this paper we investigate the relation between water pollution and economic factors such as economic size, capital to labor ratio and economic openness in two groups of developed and developing countries with paned data method. In fact we investigate the two hypothesis of Environmental Kuznets curve and pollution havens in two groups of countries. To prevent the pollution of groundwater resources in the process of economic growth, policies must be coordinated by responsible organizations. Changing crop patterns and moving toward the production of organic products to reduce the use of polluting substances in the production of agricultural products is one of these solutions. Materials and Methods: In the present study, using panel data methods, the correlation between some independent economic factors such as per capita GDP, Squared per capita GDP that both indicate Scale effect and capital to labor index with Squared capital to labor index both indicating comparative advantage effect and openness of trade and some composite indices on dependent variables, groundwater pollution, in the two groups of countries both developed and developing countries has been investigated. For this purpose, using the biological oxygen demand index (BOD as an indicator of pollution of groundwater resources and sum of exports and imports divided by GDP as an indicator of economic openness and GDP per capita as an indicator of the economy in the period of 1995 to 2006, the Environmental Kuznets curve and pollution havens hypothesis have been tested. Results Discussion: The issue of

  9. [Distribution Characteristics and Influencing Factors of Nitrate Pollution in Shallow Groundwater of Liujiang Basin].

    Science.gov (United States)

    Wang, He; Gu, Hong-biao; Chi, Bao-ming; Li, Hai-jun; Jiang, Hai-ning

    2016-05-15

    Taking the nitrate in shallow groundwater of Liujiang basin as the research object, a total of 215 groups of shallow groundwater samples were collected during the wet period in July 2014 and the drought period in April 2015 on the basis of groundwater pollution investigation. The characteristics of spatial and temporal variability and the account of nitrate pollution were analyzed based on the model of semivariogram, the geostatistics of ArcGIS and factor analysis, respectively. The results showed that the study region in the southeast was the main nitrate-polluted area, with concentrations of up to 30-120 mg · L⁻¹, in both wet and drought periods, while the nitrate-contaminated area in drought period was about 1. 4 times higher than that in wet period. The spatial distribution of nitrate was primarily influenced by human activities and the geological conditions, and secondarily by Eh, DO, pH and landform conditions. The nitrate concentration was less than 20 mg · L⁻¹ in north. Pollution in local middle area was rather serious, due to human activities and the loss of nitrogen fertilizer in agricultural cultivation; the area to the south, which was confined by impervious boundary, was seriously contaminated, as indicated by the nitrate accumulation effects.

  10. Effects of soil arsenic pollution on arsenic content and distribution in soybean%土壤砷污染对大豆砷含量与分布的影响

    Institute of Scientific and Technical Information of China (English)

    杨兰芳; 何婷; 赵莉

    2011-01-01

    通过土壤加砷盆栽大豆实验,利用氢化物发生-分光光度法测定大豆和土壤的砷含量,以研究土壤砷污染对大豆砷含量及其分布的影响.结果表明,大豆根、茎和籽粒砷含量均与土壤加砷水平呈极显著的线性相关,并呈根>茎>籽粒的规律.大豆收获后,土壤砷含量与土壤加砷水平呈极显著的线性相关,土壤砷的残留率在82%以上,与土壤加砷水平呈极显著的对数相关.大豆根、茎和籽粒的富砷量均与土壤加砷呈极显著的二次函数相关关系,大豆茎的富砷量是根富砷量的3.4~8.1倍,是籽粒富砷量的2.8~4.6倍.大豆吸收的砷有82%以上存在于地上部分,但大豆对土壤加砷的利用率只在万分之几.大豆富砷量和大豆对土壤砷的利用率均以茎最高,而富集系数则为根>茎>籽粒.总之,大豆砷含量受土壤砷水平决定,籽粒含砷量最低有利于砷污染土壤的利用,土壤砷污染具有长效性.%A soil pot experiment was conducted to investigate the effects of soil arsenic pollution on arsenic content and distribution in soybean and arsenic contents in soybean and soil were determined by the method of hydride generation spectrophotometry. The results showed that arsenic content in soybean roots, stalks and grains were significant linearly correlative to soil arsenic additions and took on an order of roots> stalks> grains. The arsenic contents in soybean-harvested soils were significant linearly correlative to soil arsenic additions,but the residual rates of arsenic in soil were more than 82% and significant exponentially correlative to soil arsenic additions. There was a significant quadratic function relationship between the arsenic accumulations in soybean roots, stalks and grains and soil arsenic additions, but the soybean arsenic accumulations in stalks were 3. 4-8.1 times as high as those in roots and 2. 8-4. 6 times as high as those in grains. Arsenic accumulations in

  11. Groundwater Resources Pollution Risk: Application of the Holman Method

    Directory of Open Access Journals (Sweden)

    M. D. Maio

    2009-01-01

    Full Text Available Problem statement: The aim of this study is to make an attempt to assess, through the application of the Holman Method, the effects that a careless management of human induced activities could have on aquifers and in particular on tapping wells used for human supply. Approach: The study had been applied to two different territories, as far as both the geomorphological and human induced aspects are concerned: the city of Aosta, the capital city of the Autonomous Aosta Valley region and three municipalities located in the centre of the Veneto region. Results: Thanks to the first results that had been obtained from the application of this method and other ones, it is hoped that a strategic territorial management approach will be adopted in the future so that the Groundwater Resources (GWR can coexist with the economic and urban developments. Conclusion: All the analysis had been implemented utilizing a Geographical Information System (GIS.

  12. Tracing nitrate pollution sources and transformation in surface- and ground-waters using environmental isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yan [Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Li, Fadong, E-mail: lifadong@igsnrr.ac.cn [Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101 (China); Zhang, Qiuying [Center for Agricultural Resources Research, Chinese Academy of Sciences, Shijiazhuang 050021 (China); Li, Jing [Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101 (China); Liu, Qiang [Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101 (China); University of Chinese Academy of Sciences, Beijing 100049 (China)

    2014-08-15

    Water pollution in the form of nitrate nitrogen (NO{sub 3}{sup −}–N) contamination is a major concern in most agricultural areas in the world. Concentrations and nitrogen and oxygen isotopic compositions of nitrate, as well as oxygen and deuterium isotopic compositions of surface and groundwater from a typical irrigated region in the North China Plain (NCP) collected from May to October in 2012 were analyzed to examine the major nitrate sources and transformations. Concentrations of NO{sub 3}{sup −}–N ranged from 0.2 to 29.6 mg/L (mean of 11.2 mg/L) in surface water, and from 0.1 to 19.4 mg/L (mean of 2.8 mg/L) in groundwater. Approximately 46.7% of the surface water samples and 10% of the groundwater samples exceeded the World Health Organization (WHO) drinking water standard for NO{sub 3}{sup −}–N. Surface water samples that exceeded the standard were collected mainly in the dry season (May and October), while groundwater samples that exceeded the standard were collected in the wet season (June). Overall, the highest nitrate levels were observed in surface water in May and in groundwater in June, indicating that fertilizer application, precipitation, and irrigation strongly influence the NO{sub 3}{sup −}–N concentrations. Analyses of isotopic compositions suggest that the main sources of nitrate are nitrification of fertilizer and sewage in surface water, in contrast, mineralization of soil organic N and sewage is the groundwater sources during the dry season. When fertilizers are applied, nitrate will be transported by precipitation through the soil layers to the groundwater in the wet season (June). Denitrification only occurred in surface water in the wet season. Attempts should be made to minimize overuse of nitrogen fertilizers and to improve nitrogen use efficiency in irrigated agricultural regions. - Highlights: • Nitrate sources in surface and groundwater were identified by multiple isotopes. • Nitrate pollution displayed obvious

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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)

  18. 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...

  19. The Characteristics of Leachate and Groundwater Pollution at Municipal Solid Waste Landfill of Ibb City, Yemen

    Directory of Open Access Journals (Sweden)

    Esmail A. Sabahi

    2009-01-01

    Full Text Available Problem statement: Yemen one of the developing country suffering from water pollution. Landfill is one of the source of water pollution. There are several boreholes located close to Ibb landfill used for drinking water. A study of composition of landfill leachate and groundwater pollution was conducted at Ibb landfill, which is located at Al-Sahool area, north of Ibb City, Yemen. Approach: The leachate was sampled at three different locations of the landfill, at the landfill itself and 15 and 20 m downstream of this landfill. Groundwater samples collected from 5 boreholes to study possible impact of leachate percolation into groundwater. Leachate and groundwater samples were collected during dry season only, due to the excessive generation of leachate during this season. Objective of this study was significant to assess degree of groundwater pollution due to Ibb landfill leachate at Al-Sahool area. The leachate and groundwater were physically and chemically characterized by using spectrophotometer HACH, BOD Trak HACH, flame photometer (PFP 7 and Inductively Coupled Plasma of Optical Emission Spectrometry (ICP-OES model Vista MPX. Parameters measured were pH, temperature, Electrical Conductivity (EC, Total Dissolved Solids (TDS, Dissolved Oxygen (DO, Fluoride (F, Chloride (Cl, Sulphate (SO4, Nitrites (NO2, Nitrates (NO3, ammonia-N (NH3-N, heavy metals (Pb, Zn, Ni, Cr, Cd, Cu, major cations (Na, Mg, Ca, K, Fe and biological parameters (COD, BOD5 and coliform group bacteria. Results: The results showed that, leachate at landfill most likely in methanogenic phase, based on the alkaline pH value recorded (pH = 8.46. The results also showed that 4 out of 5 boreholes were contaminated, where concentration of physico-chemical parameters are above the standard acceptable levels which required for drinking water adapted by Yemen's ministry of water and environment and by word standard. Conclusion: Therefore, landfill is dangerous for environment so

  20. Groundwater pollution with heavy metals in the Ibar alluvium near Raška (Serbia

    Directory of Open Access Journals (Sweden)

    Miladinović Branko

    2012-01-01

    Full Text Available As a result of the operation of an ore flotation facility at Donja Rudnica near Raška, Serbia, during the period from 1972 to 2002, flotation tailings and wastewater of highly complex chemical compositions were deposited in the alluvial plain of the Ibar River. Due to the excellent groundwater flow characteristics of the alluvial formations underlying the tailings dump, the groundwater and soil over an extended area were continually polluted. High concentrations of heavy metals (Fe = 7.38 mg/L. Zn = 4.04 mg/L, Pb = 2.17 mg/L in the soil and concentrations of sulfate as high as 3709 mg/L, and pH levels of 4.2 in the groundwater have been recorded at some locations. This paper draws attention to the potential risk this site poses for the conservation of biodiversity over the extended area.

  1. Multiobjective optimization for Groundwater Nitrate Pollution Control. Application to El Salobral-Los Llanos aquifer (Spain).

    Science.gov (United States)

    Llopis-Albert, C.; Peña-Haro, S.; Pulido-Velazquez, M.; Molina, J.

    2012-04-01

    Water quality management is complex due to the inter-relations between socio-political, environmental and economic constraints and objectives. In order to choose an appropriate policy to reduce nitrate pollution in groundwater it is necessary to consider different objectives, often in conflict. In this paper, a hydro-economic modeling framework, based on a non-linear optimization(CONOPT) technique, which embeds simulation of groundwater mass transport through concentration response matrices, is used to study optimal policies for groundwater nitrate pollution control under different objectives and constraints. Three objectives were considered: recovery time (for meeting the environmental standards, as required by the EU Water Framework Directive and Groundwater Directive), maximum nitrate concentration in groundwater, and net benefits in agriculture. Another criterion was added: the reliability of meeting the nitrate concentration standards. The approach allows deriving the trade-offs between the reliability of meeting the standard, the net benefits from agricultural production and the recovery time. Two different policies were considered: spatially distributed fertilizer standards or quotas (obtained through multi-objective optimization) and fertilizer prices. The multi-objective analysis allows to compare the achievement of the different policies, Pareto fronts (or efficiency frontiers) and tradeoffs for the set of mutually conflicting objectives. The constraint method is applied to generate the set of non-dominated solutions. The multi-objective framework can be used to design groundwater management policies taking into consideration different stakeholders' interests (e.g., policy makers, agricultures or environmental groups). The methodology was applied to the El Salobral-Los Llanos aquifer in Spain. Over the past 30 years the area has undertaken a significant socioeconomic development, mainly due to the intensive groundwater use for irrigated crops, which has

  2. 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

  3. Determination of Organic Pollutants in Small Samples of Groundwaters by Liquid-Liquid Extraction and Capillary Gas Chromatography

    DEFF Research Database (Denmark)

    Harrison, I.; Leader, R.U.; Higgo, J.J.W.

    1994-01-01

    A method is presented for the determination of 22 organic compounds in polluted groundwaters. The method includes liquid-liquid extraction of the base/neutral organics from small, alkaline groundwater samples, followed by derivatisation and liquid-liquid extraction of phenolic compounds after...

  4. 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

  5. Research on mechanism of groundwater pollution from mine water in abandoned mines

    Institute of Scientific and Technical Information of China (English)

    WANG Lai-gui; LI Xi-lin; LIU Ling; HAN Liang

    2008-01-01

    In order to understand the mechanism and regularity of the groundwater contamination from mine water of abandoned mines, experiments were conducted on an abandoned coal mine in Fuxin, a representative city with lots of mine water in northeast China. The groundwater pollution from different contaminants of coal-mining voids (total hardness, SO2-4, Cl and total Fe) and pollution factors transportation situation in the coal rock were simulated by soil column experiment under the conditions of mine water leaching and main water leaching (similar to rainwater leaching), and the water-rock interaction mechanism was discussed during mine water infiltration through saturated coal rock by application of principle of mass conservation, based on physical properties of coal rock, as well as monitored chemical composition. The results show that, compared with the clear water leaching process, trends of change in pollutant concentrations presented different characteristics in the mine water leaching process. Groundwater is contaminated by the water rock interactions such as migration & accumulation, adsorption & transformation,dissolution & desorption and ion exchange during the mine water permeation. The experiments also suggest that at first dissolution rate of some kinds of dissoluble salts is high,but it decreases with leaching time, even to zero during both the mine water leaching and main water leaching.

  6. Integrated techniques to identify groundwater vulnerability to pollution in a highly industrialized terrain, Tamilnadu, India.

    Science.gov (United States)

    Srinivasamoorthy, Krishnaraj; Vijayaraghavan, K; Vasanthavigar, Murugesan; Rajivgandhi, R; Sarma, V S

    2011-11-01

    Investigation has been made to identify groundwater vulnerability to pollution by using geoelectric and hydrochemical investigations in an important industrial town Mettur located in Tamilnadu state of India. Schlumberger vertical electric soundings were carried out in 23 locations and groundwater samples collected from bore wells in the same locations. The resistivity value with groundwater in areas influenced by sewages from industries, domestic and agricultural practices in the central and southern part of the study area. The calculated specific conductance was noted higher than EC in central and southern part of the study area with low resistivity indicating the contaminated nature of groundwater. Concentrations of Ca, Na, Mg and K along with Cl, HCO(3), SO(4) and NO(3) were higher in certain locations when compared with WHO and ISI standards. The facies concept demarcated four groups based on the nature of groundwater contamination. The trace elements Fe and Pb were higher in locations confined to industrial zones and Zn and Cu were within the prescribed limit in all the samples.

  7. 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.

  8. Evaluation of the relation between groundwater pollution and the pollutant load on surface waters

    NARCIS (Netherlands)

    Groenendijk, P.; Roest, C.W.J.

    1996-01-01

    The importance of the relation between groundwater and surface water is demonstrated by the impact of water quality standards on permissible nitrogen losses at farm level. The effects of the intended fertilization reduction measures on agricultural production justify a thorough examination of the

  9. Sequential optimal monitoring network design and iterative spatial estimation of pollutant concentration for identification of unknown groundwater pollution source locations.

    Science.gov (United States)

    Prakash, Om; Datta, Bithin

    2013-07-01

    One of the difficulties in accurate characterization of unknown groundwater pollution sources is the uncertainty regarding the number and the location of such sources. Only when the number of source locations is estimated with some degree of certainty that the characterization of the sources in terms of location, magnitude, and activity duration can be meaningful. A fairly good knowledge of source locations can substantially decrease the degree of nonuniqueness in the set of possible aquifer responses to subjected geochemical stresses. A methodology is developed to use a sequence of dedicated monitoring network design and implementation and to screen and identify the possible source locations. The proposed methodology utilizes a combination of spatial interpolation of concentration measurements and simulated annealing as optimization algorithm for optimal design of the monitoring network. These monitoring networks are to be designed and implemented sequentially. The sequential design is based on iterative pollutant concentration measurement information from the sequentially designed monitoring networks. The optimal monitoring network design utilizes concentration gradient information from the monitoring network at previous iteration to define the objective function. The capability of the feedback information based iterative methodology is shown to be effective in estimating the source locations when no such information is initially available. This unknown pollution source locations identification methodology should be very useful as a screening model for subsequent accurate estimation of the unknown pollution sources in terms of location, magnitude, and activity duration.

  10. 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.

  11. 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

  12. 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.

  13. 砷的地球化学习性及尾矿源砷污染防治%Arsenic Geochemical Behaviour and Prevention of Arsenic Pollution from Sulfide Tailings

    Institute of Scientific and Technical Information of China (English)

    徐沛斌; 雷良奇; 莫斌吉; 罗远红

    2012-01-01

    Arsenic is carcinogenic and teratogenic and toxic elements and the arsenic pollution exists generally in the metal sulfide mining. When the physical-chemical environment being changed,the different morphology and valence state of arsenic also can be transformed,and it can gather in soil and water and lead to arsenic pollution . The common arsenide ar-senopyrite can generate scorodite in the effect of oxygen and water. Under acidic conditions hydrolyze into arsenic acid,thus it can leaching and migration by wastewater. According to mechanism of arsenic contamination,demonstration that from mine tailings and source control and prevention of arsenic pollution and the importance of feasibility. In the arsenic pollution prevention and control,new mine tailings under water storage,acid neutralization and surface sealing technology,existing pollution tailings permeable reactive barrier technology and bioremediation technology,they are more mature,practical arsenic pollution control technology.%致癌和致畸有毒元素砷的污染普遍存在于金属硫化物矿山开采中.当物理化学条件发生变化时,不同形态和价态的砷可发生转化,并在土壤和水体中富集而造成砷污染,常见砷化物毒砂在O2和H2O的作用下生成臭葱石,并在酸性条件下水解成砷酸,从而被废水淋滤迁移.根据砷污染机理,论证了从矿山尾矿的源头控制和预防砷污染的重要性及可行性;在砷污染防治方面,新矿山尾矿的水下存储、酸性中和及表面封存技术,已存在污染的尾矿的渗透反应栅技术和生物修复技术均较为成熟、切实可行.

  14. Characterization and mobility of arsenic and heavy metals in soils polluted by the destruction of arsenic-containing shells from the Great War.

    Science.gov (United States)

    Thouin, Hugues; Le Forestier, Lydie; Gautret, Pascale; Hube, Daniel; Laperche, Valérie; Dupraz, Sebastien; Battaglia-Brunet, Fabienne

    2016-04-15

    Destruction of chemical munitions from World War I has caused extensive local top soil contamination by arsenic and heavy metals. The biogeochemical behavior of toxic elements is poorly documented in this type of environment. Four soils were sampled presenting different levels of contamination. The range of As concentrations in the samples was 1937-72,820mg/kg. Concentrations of Zn, Cu and Pb reached 90,190mg/kg, 9113mg/kg and 5777mg/kg, respectively. The high clay content of the subsoil and large amounts of charcoal from the use of firewood during the burning process constitute an ample reservoir of metals and As-binding materials. However, SEM-EDS observations showed different forms of association for metals and As. In metal-rich grains, several phases were identified: crystalline phases, where arsenate secondary minerals were detected, and an amorphous phase rich in Fe, Zn, Cu, and As. The secondary arsenate minerals, identified by XRD, were adamite and olivenite (zinc and copper arsenates, respectively) and two pharmacosiderites. The amorphous material was the principal carrier of As and metals in the central part of the site. This singular mineral assemblage probably resulted from the heat treatment of arsenic-containing shells. Microbial characterization included total cell counts, respiration, and determination of As(III)-oxidizing activities. Results showed the presence of microorganisms actively contributing to metabolism of carbon and arsenic, even in the most polluted soil, thereby influencing the fate of bioavailable As on the site. However, the mobility of As correlated mainly with the availability of iron sinks.

  15. Assessing groundwater pollution hazard changes under different socio-economic and environmental scenarios in an agricultural watershed

    Energy Technology Data Exchange (ETDEWEB)

    Lima, M. Lourdes, E-mail: mlima@mdp.edu.ar [Instituto de Geología de Costas y del Cuaternario, FCEyN, Universidad Nacional de Mar del Plata, Funes 3350, Nivel 1, 7600 Mar del Plata (Argentina); Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) (Argentina); Romanelli, Asunción, E-mail: aromanel@mdp.edu.ar [Instituto de Geología de Costas y del Cuaternario, FCEyN, Universidad Nacional de Mar del Plata, Funes 3350, Nivel 1, 7600 Mar del Plata (Argentina); Instituto de Investigaciones Marinas y Costeras (IIMyC), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) (Argentina); Massone, Héctor E., E-mail: hmassone@mdp.edu.ar [Instituto de Geología de Costas y del Cuaternario, FCEyN, Universidad Nacional de Mar del Plata, Funes 3350, Nivel 1, 7600 Mar del Plata (Argentina)

    2015-10-15

    This paper proposes a modeling approach for assessing changes in groundwater pollution hazard under two different socio-economic and environmental scenarios: The first one considers an exponential growth of agriculture land-use (Relegated Sustainability), while the other deals with regional economic growth, taking into account, the restrictions put on natural resources use (Sustainability Reforms). The recent (2011) and forecasted (2030) groundwater pollution hazard is evaluated based on hydrogeological parameters and, the impact of land-use changes in the groundwater system, coupling together a land-use change model (Dyna-CLUE) with a groundwater flow model (MODFLOW), as inputs to a decision system support (EMDS). The Dulce Stream Watershed (Pampa Plain, Argentina) was chosen to test the usefulness and utility of this proposed method. It includes a high level of agricultural activities, significant local extraction of groundwater resources for drinking water and irrigation and extensive available data regarding aquifer features. The Relegated Sustainability Scenario showed a negative change in the aquifer system, increasing (+ 20%; high–very high classes) the contribution to groundwater pollution hazard throughout the watershed. On the other hand, the Sustainability Reforms Scenario displayed more balanced land-use changes with a trend towards sustainability, therefore proposing a more acceptable change in the aquifer system for 2030 with a possible 2% increase (high–very high classes) in groundwater pollution hazard. Results in the recent scenario (2011) showed that 54% of Dulce Stream Watershed still shows a moderate to a very low contribution to groundwater pollution hazard (mainly in the lower area). Therefore, from the point of view of natural resource management, this is a positive aspect, offering possibilities for intervention in order to prevent deterioration and protect this aquifer system. However, since it is quite possible that this aquifer status

  16. Assessment of groundwater vulnerability to pollution using the Kherici’s method in the Talezza plain, Collo region (NE Algeria

    Directory of Open Access Journals (Sweden)

    Attoui Badra

    2017-06-01

    Full Text Available The intrinsic vulnerability of groundwater aquifers refers to their sensitivity to all contamination coming from soil surface irrespective of the nature of the polluting. In order to improve the protection of groundwater, there must be a reduction in the infiltration of contaminants towards the reservoir through the impacting factors determination of this phenomenon by means of research. There are collected models that include particular number of factors which allow the determination of a sign of groundwater vulnerability of all superficial pollutions.

  17. 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.

  18. Sensitivity analysis of geostatistical approach to recover pollution source release history in groundwater

    Science.gov (United States)

    Long, Y. Q.; Cui, T. T.; Li, W.; Yang, Z. P.; Gai, Y. W.

    2017-08-01

    The geostatistical approach has been studied for many year to identify the pollution source re-lease history in groundwater. We focus on the influence of observation error and hydraulic parameters on the groundwater pollution identification (PSI) result in the paper. Numerical experiment and sensitivity analysis are carried out to find the influence of observation point configuration, error and hydraulic parameters on the PSI result in a 1D homogeneous aquifer. It has been found out that if concentration observation data could accurately describe the characteristics of the real concentration plume at the observed time point, a nice identification of the pollution release process could be obtained. If the calculated pollution discharge process has good similarity with the real discharge process, the order of the observation error fell within 10-6 and 10-3.5, the dispersion coefficient varies fells within -10% and 5%, and the actual mean velocity fell within ±2%. The actual mean velocity is the most sensitive parameter of the geostatistical approach in this case.

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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)

  5. Derivation of Threshold Values for Groundwater in Romania, in order to distinguish Point & Diffuse pollution from natural background levels

    NARCIS (Netherlands)

    Schipper, P.N.M.; Radu, E.; Vliegenthart, F.; Balaet, R.

    2010-01-01

    Romania aims to adopt and implement the European Union's legislation, also including that for the field of water management. Like other countries, groundwater in Romania is locally polluted from point sources, such as leaking landfills, as well as from diffuse pollution sources, include fertilizers,

  6. Assessing groundwater pollution hazard changes under different socio-economic and environmental scenarios in an agricultural watershed.

    Science.gov (United States)

    Lima, M Lourdes; Romanelli, Asunción; Massone, Héctor E

    2015-10-15

    This paper proposes a modeling approach for assessing changes in groundwater pollution hazard under two different socio-economic and environmental scenarios: The first one considers an exponential growth of agriculture land-use (Relegated Sustainability), while the other deals with regional economic growth, taking into account, the restrictions put on natural resources use (Sustainability Reforms). The recent (2011) and forecasted (2030) groundwater pollution hazard is evaluated based on hydrogeological parameters and, the impact of land-use changes in the groundwater system, coupling together a land-use change model (Dyna-CLUE) with a groundwater flow model (MODFLOW), as inputs to a decision system support (EMDS). The Dulce Stream Watershed (Pampa Plain, Argentina) was chosen to test the usefulness and utility of this proposed method. It includes a high level of agricultural activities, significant local extraction of groundwater resources for drinking water and irrigation and extensive available data regarding aquifer features. The Relegated Sustainability Scenario showed a negative change in the aquifer system, increasing (+20%; high-very high classes) the contribution to groundwater pollution hazard throughout the watershed. On the other hand, the Sustainability Reforms Scenario displayed more balanced land-use changes with a trend towards sustainability, therefore proposing a more acceptable change in the aquifer system for 2030 with a possible 2% increase (high-very high classes) in groundwater pollution hazard. Results in the recent scenario (2011) showed that 54% of Dulce Stream Watershed still shows a moderate to a very low contribution to groundwater pollution hazard (mainly in the lower area). Therefore, from the point of view of natural resource management, this is a positive aspect, offering possibilities for intervention in order to prevent deterioration and protect this aquifer system. However, since it is quite possible that this aquifer status (i

  7. Assessment of groundwater pollution in Tokyo using PPCPs as sewage markers.

    Science.gov (United States)

    Kuroda, Keisuke; Murakami, Michio; Oguma, Kumiko; Muramatsu, Yuki; Takada, Hideshige; Takizawa, Satoshi

    2012-02-07

    While the occurrence of pharmaceuticals and personal care products (PPCPs) in groundwater has typically been reported in bank filtration sites, irrigated fields, septic tanks, and sewage disposal practices, fewer studies have been conducted in highly urbanized areas, where infiltration of treated or untreated sewage is not supposed to be a source of groundwater recharge. Furthermore, little is known about the occurrence of various kinds of PPCPs in relation to microbial indicators in groundwater from different types of aquifers. Thus, we examined the city-wide occurrence of selected PPCPs (diethyltoluamide, crotamiton, ethenzamide, propyphenazone, carbamazepine, and caffeine) and E. coli in 50 groundwaters from unconfined aquifers (groundwater contamination could take place due to decrepit sewer networks. PPCPs were detected in unconfined aquifers and springs (23/34 samples, 68%), and in confined aquifers (7/16 samples, 44%). Compared with published results for sewage influents, concentrations of PPCPs, excluding caffeine, were generally 1-2 orders of magnitude lower, while in some samples concentrations were quite comparable. The high occurrence rate of PPCPs, even in confined aquifers, indicated that such aquifers are not always protected from pollution by sewage near the land surface. Among the PPCPs analyzed, carbamazepine and crotamiton were most frequently detected, which would appear to be owing to their high persistence, combined with the high concentration of crotamiton in sewage. Crotamiton was detected in all four E. coli-positive groundwaters, and thus may potentially serve as a precautionary indicator of E. coli contamination. Using carbamazepine as a sewage marker, we estimated that 0.8%-1.7% of the dry-weather flow of sewage was leaking out into the unconfined aquifers.

  8. Source apportionment of fluorine pollution in regional shallow groundwater at You'xi County southeast China.

    Science.gov (United States)

    Lü, Jian; Qiu, Haiyuan; Lin, Huangbin; Yuan, Yuan; Chen, Zhi; Zhao, Rurong

    2016-09-01

    Source apportionment of fluorine pollution in the regional shallow groundwater at You'xi County, southeast China, has been analyzed by means of monitoring F(-) ion change characteristics in this area. Meanwhile, pollution sources and influencing factors of the shallow groundwater have been uncovered by studying the correlation between F(-) and other related ions such as Na(+), Ca(2+), Cl(-), NO3(-), HCO3(-), as well as (K(+) + Na(+))/Ca(2+) ratio (R) and pH effect. The results show that F(-) ions in shallow groundwater at the study area come mainly from the dissolution of fluorinated minerals in a form of fluorite (CaF2), the so-called water-rock interaction, and there is a higher possibility for the occurrence of fluorine water where the ratio of (K(+) + Na(+))/Ca(2+) exceeds a value of 2.1. Moreover, the release and migration of F(-) ions have been favored by the alkaline environment in this study area. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. - On Investigating Pollution of Groundwater from Atenda Abattoir Wastes, Ogbomoso, Nigeria

    Directory of Open Access Journals (Sweden)

    Adewoye, Abosede Olufunmilayo

    2012-09-01

    Full Text Available The incidence of waterborne diseases arising from pollution of shallow wells in abattoir environment has been on the increase in Ogbomoso community. This project work was carried out in order to examine the geochemical constituents of water samples taken from selected wells in Atenda abattoir environment, Ogbomoso, Oyo State, Nigeria. The effect of abattoir wastes on the groundwater samples and geotechnical analyses of soil samples taken from two points around the abattoir waste dump, and another sample from a control point free from pollution and far away from where the first two samples were taken, were also carried out. Geophysical investigation of the Atenda area was carried out using Vertical Electrical Sounding (VES of Electrical Resistivity Method (ERM, Electrical Resistivity Tomography (ERT, and also, Very Low Frequency (VLF electromagnetic method. The geophysical investigation was carried out to determine the lithology of the study area, track the contaminant plume view and compute the depth to bedrock in the study area. It was observed that a strong correlation exist between leachates from the Atenda abattoir location and sampled wells in the immediate environment. A groundwater monitoring programme to determine groundwater quality status of wells in the neighbourhood of abattoirs is recommended for implementation to safeguard the health of innocent residents in the vicinity.

  10. Intrinsic and specific vulnerability of groundwater in central Spain: the risk of nitrate pollution

    Science.gov (United States)

    Martínez-Bastida, Juan J.; Arauzo, Mercedes; Valladolid, Maria

    2010-05-01

    The intrinsic vulnerability of groundwater in the Comunidad de Madrid (central Spain) was evaluated using the DRASTIC and GOD indexes. Groundwater vulnerability to nitrate pollution was also assessed using the composite DRASTIC (CD) and nitrate vulnerability (NV) indexes. The utility of these methods was tested by analyzing the spatial distribution of nitrate concentrations in the different aquifers located in the study area: the Tertiary Detrital Aquifer, the Moor Limestone Aquifer, the Cretaceous Limestone Aquifer and the Quaternary Aquifer. Vulnerability maps based on these four indexes showed very similar results, identifying the Quaternary Aquifer and the lower sub-unit of the Moor Limestone Aquifer as deposits subjected to a high risk of nitrate pollution due to intensive agriculture. As far as the spatial distribution of groundwater nitrate concentrations is concerned, the NV index showed the greatest statistical significance ( p real impact of each type of land use. The results of this study provide a basis on which to guide the designation of nitrate vulnerable zones in the Comunidad de Madrid, in line with European Union Directive 91/676/EEC.

  11. Overview of groundwater sources and water-supply systems, and associated microbial pollution, in Finland, Norway and Iceland

    Science.gov (United States)

    Kløve, Bjørn; Kvitsand, Hanne Margrethe Lund; Pitkänen, Tarja; Gunnarsdottir, Maria J.; Gaut, Sylvi; Gardarsson, Sigurdur M.; Rossi, Pekka M.; Miettinen, Ilkka

    2017-06-01

    The characteristics of groundwater systems and groundwater contamination in Finland, Norway and Iceland are presented, as they relate to outbreaks of disease. Disparities among the Nordic countries in the approach to providing safe drinking water from groundwater are discussed, and recommendations are given for the future. Groundwater recharge is typically high in autumn or winter months or after snowmelt in the coldest regions. Most inland aquifers are unconfined and therefore vulnerable to pollution, but they are often without much anthropogenic influence and the water quality is good. In coastal zones, previously emplaced marine sediments may confine and protect aquifers to some extent. However, the water quality in these aquifers is highly variable, as the coastal regions are also most influenced by agriculture, sea-water intrusion and urban settlements resulting in challenging conditions for water abstraction and supply. Groundwater is typically extracted from Quaternary deposits for small and medium municipalities, from bedrock for single households, and from surface water for the largest cities, except for Iceland, which relies almost entirely on groundwater for public supply. Managed aquifer recharge, with or without prior water treatment, is widely used in Finland to extend present groundwater resources. Especially at small utilities, groundwater is often supplied without treatment. Despite generally good water quality, microbial contamination has occurred, principally by norovirus and Campylobacter, with larger outbreaks resulting from sewage contamination, cross-connections into drinking water supplies, heavy rainfall events, and ingress of polluted surface water to groundwater.

  12. Overview of groundwater sources and water-supply systems, and associated microbial pollution, in Finland, Norway and Iceland

    Science.gov (United States)

    Kløve, Bjørn; Kvitsand, Hanne Margrethe Lund; Pitkänen, Tarja; Gunnarsdottir, Maria J.; Gaut, Sylvi; Gardarsson, Sigurdur M.; Rossi, Pekka M.; Miettinen, Ilkka

    2017-03-01

    The characteristics of groundwater systems and groundwater contamination in Finland, Norway and Iceland are presented, as they relate to outbreaks of disease. Disparities among the Nordic countries in the approach to providing safe drinking water from groundwater are discussed, and recommendations are given for the future. Groundwater recharge is typically high in autumn or winter months or after snowmelt in the coldest regions. Most inland aquifers are unconfined and therefore vulnerable to pollution, but they are often without much anthropogenic influence and the water quality is good. In coastal zones, previously emplaced marine sediments may confine and protect aquifers to some extent. However, the water quality in these aquifers is highly variable, as the coastal regions are also most influenced by agriculture, sea-water intrusion and urban settlements resulting in challenging conditions for water abstraction and supply. Groundwater is typically extracted from Quaternary deposits for small and medium municipalities, from bedrock for single households, and from surface water for the largest cities, except for Iceland, which relies almost entirely on groundwater for public supply. Managed aquifer recharge, with or without prior water treatment, is widely used in Finland to extend present groundwater resources. Especially at small utilities, groundwater is often supplied without treatment. Despite generally good water quality, microbial contamination has occurred, principally by norovirus and Campylobacter, with larger outbreaks resulting from sewage contamination, cross-connections into drinking water supplies, heavy rainfall events, and ingress of polluted surface water to groundwater.

  13. 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.

  14. 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.

  15. Chromium speciation in groundwater of a tannery polluted area of Chennai City, India.

    Science.gov (United States)

    Kumar, A Ramesh; Riyazuddin, P

    2010-01-01

    Chromium speciation in groundwater of a tannery polluted area was investigated for the distribution of chromium species and the influence of redox couples such as Fe(III)/Fe(II) and Mn(IV)/Mn(II). Speciation analysis was carried out by ammonium pyrolidinedithiocarbamate (APDC)-methylisobutylketone (MIBK) procedure. The groundwater samples were analyzed for Cr(III), Cr(VI), and Cr(III)-organic complexes. The APDC could not extract the Cr(III)-organic complexes, but HNO3 digestion of the groundwater samples released the Cr(III)-organic complexes. The groundwater of the area is relatively oxidizing with redox potential (Eh) and dissolved oxygen (DO) ranged between 65 and 299 mV and 0.25 and 4.65 mg L(-1), respectively. The Fe(II) reduction of Cr(VI) was observed in some wells, but several wells that had Fe(II)/Cr(VI) concentrations more than the stoichiometric ratio (3:1) of the reduction reaction also had appreciable concentration of Cr(VI). This could partly be due to the oxidation of Fe(II) to Fe(III) by DO. It appears that the occurrence of Mn more than the Fe(II) concentration was also responsible for the presence of Cr(VI). Other reasons could be the Fe(II) complexation by organic ligands and the loss of reducing capacity of Fe(II) due to aquifer materials, but could not be established in this study.

  16. Quantitative assessment of possible human health risk associated with consumption of