| 1. |
- Annaduzzaman, Md., et al.
(author)
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Tubewell platform color : A low-cost and rapid screening tool for arsenic and manganese in drinking water
- 2013
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Conference paper (other academic/artistic)abstract
- Presence of high level of geogenic arsenic (As) in groundwater is one of the major and adverse drinking water quality problem all over the world, especially in Southeast Asia, where groundwater is the prominent drinking water source. Bangladesh is already considered as one of the most As affected territories, where As contamination in the groundwater is key environmental disasters. Recently besides As, presence of high level of manganese (Mn) in drinking water has also got attention due to its neurological effect on children. It becomes very essential to formulate a reliable safe drinking water management policy to reduce the health threat caused by drinking As and Mn contained groundwater. The development of a simple low cost technique for the determination of As and Mn in drinking water wells is an important step to formulate this policy. The aim of this study was to evaluate the potentiality of tubewell platform color as low-cost, quick and convenient screening tool for As and Mn in drinking water wells (n=272) in a highly arsenic affected area on Matlab, Southeastern Bangladesh.The result shows strong correlation between the development of red color stain on tubewell platform and As enrichment in the corresponding tubewell water compared to WHO drinking water guideline (10 μg/L) as well as Bangladesh drinking water standard (BDWS) (50 μg/L), with certainty values of 98.7% and 98.3% respectively. The sensitivity and efficiency of red colored platforms to screen high As water in tubewells are 98% and 97% respectively at 10 μg/L, whereas at cut-off level of 50μg/L both sensitivity and efficiency values are 98%. This study suggests that red colored platform could be potentially used for primary identification of tubewells with elevated level of As and thus could prioritise sustainable As mitigation management in developing countries. Due to lack of tubewells with black colored platform in the study area, the use of platform color concept for screening of Mn enriched water in the wells have not been tested significantly, which requires further study.Acknowledgements: This study was carried out with support from the Liuuaeus-Palme Academic Exchange Programme supported by International Programs Office (IPK) and the KTH led joint collaborative action research project on Sustainable Arsenic Mitigation- SASMIT (Sid Contribution 750000854).
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| 2. |
- Aullón Alcaine, Anna, et al.
(author)
-
Geogenic arsenic and fluoride in shallow aquifers of northeastern La Pampa, Argentina : mobility constraints
- 2013
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Conference paper (other academic/artistic)abstract
- High concentrations of geogenic arsenic (As) and fluoride (F-) in groundwater have been reported at elevated concentrations in different parts of the Chaco-Pampean Plain, in Argentina, where more than 2 million people may be exposed to high levels of these toxic elements through drinking water. Groundwater from the shallow aquifer is far exceeding the permissible WHO Standard limits of 10 μg/L for As and 1.5 mg/L for fluoride, as well as the Argentinean Standard limit of 50 μg/L for As. Geogenic As results due to the weathering of ash originated by volcanic eruptions from the Andean Cordillera and transported by wind and deposited along with the sediments and also as discrete layers and lenses over large geographical area containing around 90% of rhyolitic glass. Groundwater is hosted in a sandy silty interconnected system of aquifers and aquitards within the The Pampean aquifer. A total of 44 groundwater samples were collected from the shallow aquifers in NE of La Pampa province. Two rural areas covering an area of 600km2 in Quemú Quemú (QQ) and 300km2 in Intendente Alvear (IA) were investigated in the present study. Groundwater was circum-neutral to alkaline (pH 7.43-9.18), predominantly oxidizing (Eh ~0.24 V) with widely variable EC range (456-11,400 μS/cm). The major cation dissolved in groundwater was Na+, while the predominant anions were HCO3-, Cl- and SO42-, respectively. Water type in QQ was mostly Na-HCO3- while in IA, the composition differed between Na-HCO3- and Na-Cl-SO42- water types. Groundwater composition showed high degree of mineralization and high salinity evidenced by high EC. In discharge areas, high evaporation rates result in high salinity of shallow groundwater and visible salts incrustations on the surface of the lakes. Elevated concentrations of NO3- and PO43- observed in some wells indicated possible anthropogenic contamination. Total As concentration in groundwater from QQ ranged from 5.58 to 535 μg/L, where 94% of the wells exceeded the WHO standard limit for safe drinking water of 10 μg/L, and 56% of the wells exceeded the old Argentine standard limit of 50 μg/L. F- concentrations revealed heterogeneity and high concentrations in some wells (0.5-14.2 mg/L), 78% of samples in QQ study area exceeded the WHO standard limit of 1.5 mg/L. Under oxidizing conditions and neutral to alkaline pH, arsenate (AsV) species predominated, mainly in HAsO42- forms. As "hotspots" indicated locally contamination and correlated positively with F-, HCO3-, B and V and showed negative correlation with salinity, dissolved Fe, Al and Mn. The mechanisms involved in the mobilization of As in the shallow aquifers are controlled by the rise of pH, variations in Eh conditions and the presence of competitor ions (HCO3-, PO43-, Si, V oxyanions). Geochemical processes like adsorption/desorption, precipitation/dissolution and redox reactions may trigger to As mobilization in the shallow aquifers of La Pampa region.
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| 3. |
- Aullón Alcaine, Anna, et al.
(author)
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Hydrogeochemical controls on the mobility of arsenic, fluoride and other geogenic co-contaminants in the shallow aquifers of northeastern La Pampa Province in Argentina
- 2020
-
In: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 715
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Journal article (peer-reviewed)abstract
- Elevated Arsenic (As) and Fluoride (F) concentrations in groundwater have been studied in the shallow aquifers of northeastern of La Pampa province, in the Chaco-Pampean plain, Argentina. The source of As and co-contaminants is mainly geogenic, from the weathering of volcanic ash and loess (rhyolitic glass) that erupted from the Andean volcanic range. In this study we have assessed the groundwater quality in two semi-arid areas of La Pampa. We have also identified the spatial distribution of As and co-contaminants in groundwater and determined the major factors controlling the mobilization of As in the shallow aquifers. The groundwater samples were circum-neutral to alkaline (7.4 to 92), oxidizing (Eh similar to 0.24 V) and characterized by high salinity (EC = 456-11,400 mu S/cm) and Na+-HCO3- water types in recharge areas. Carbonate concretions ("tosca") were abundant in the upper layers of the shallow aquifer. The concentration of total As (5.6 to 535 mu g/L) and F (0.5 to 14.2 mg/L) were heterogeneous and exceeded the recommended WHO Guidelines and the Argentine Standards for drinking water. The predominant As species were arsenate As(V) oxyanions, determined by thermodynamic calculations. Arsenic was positively correlated with bicarbonate (HCO3-), fluoride (F), boron (B) and vanadium (V), but negatively correlated with iron (Fe), aluminium (Al), and manganese (Mn), which were present in low concentrations. The highest amount of As in sediments was from the surface of the dry lake. The mechanisms for As mobilization are associated with multiple factors: geochemical reactions, hydrogeological characteristics of the local aquifer and climatic factors. Desorption of As(V) at high pH, and ion competition for adsorption sites are considered the principal mechanisms for As mobilization in the shallow aquifers. In addition, the long-term consumption of the groundwater could pose a threat for the health of the local community and low cost remediation techniques are required to improve the drinking water quality.
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| 4. |
- Balfors, Berit, et al.
(author)
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Contamination of water resources in Takwa mining area of Ghana : Linking technical, social-economic and gender dimensions
- 2007
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Reports (other academic/artistic)abstract
- Ghana is Africa’s second largest producer of gold with gold deposits in western part of the country. There are seven large-scale mines and 168 small-scale mining concessions valid in the region. Wassa West District is an important mining area, with Tarkwa as administrative capital. In recent years, the area has been exposed to lead, cadmium, arsenic, mercury and cyanide. Both small and large-scale mining industries have reportedly contaminated rivers, streams, dug wells and boreholes with heavy metals such as lead, cadmium, arsenic, mercury and cyanide. There has been significant adverse impact upon health, economy, and social life that may be felt differently by women and men, raising the question of sustainable access to safe water as a millennium development goal (MDG) in the area. A multi-disciplinary approach was adopted in the project with distinct work components on the technical as well as on social, gender and policy aspects. It also aimed to suggest integrated strategies to address the problem so as to ensure achievement of the MDGs. Based upon a field study in 37 local communities coupled with water and sediment analysis from the area, the research indicated the existence of not only higher levels of metal contaminants in local water resources in Tarkwa area, particularlymanganese and iron, but also arsenic and aluminium in some wells. However, water resources, particularly groundwater is currently safe for human consumption but the spillages of cyanide and other effluents into surface streams have health and ecological implications. Levels of mercury in stream sediments are high with a clear risk of methylation of the mercury and transfer in the food chain via fish to humans. Regarding the impact of mining, it was found that for women who are the primary domestic water managers, contamination of local water sources has forced them to fetch water from greater distances, and livelihoods are hampered due to the fish loss through cyanide spillages in streams. Another finding was the lack of trust and rising water conflicts between mining authorities and the local communities. Regarding the policy aspects underlying the problem, it was found that there is a lack of coordination between the 3 policy areas, namely, rural water supply, mining, and environmental impact assessment (EIA) and environmental protection to the detriment of women as water users and domestic water managers. While impact of mining is increasingly seen as an issue of human rights violation, little is being done to strengthen participatory approaches especially involving women in rural water supply programs. The detailed analysis of the EIA regulations reveals that most mining have not undertaken any comprehensive EIA guiding their operations. A number of recommendations have emerged from the integrated perspective attempted to be developed through this research. These include a need for further in-depth explorations on the situation of contamination in groundwater and surface waters as well as stream sediments in the area; the need to resolve the situations of water conflicts between the local communities and the mining authorities by promoting greater public participation; and the need to minimize the gaps between the three related policy frameworks. Also, there is a necessity to strengthen environmental compliance on part of the mining companies so as to uphold the quality of water resources in the area.
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| 5. |
- Bhattacharya, Prosun, 1962-, et al.
(author)
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Arsenic in Groundwater of Bangladesh : Options for Safe Drinking Water
- 2010
-
Reports (other academic/artistic)abstract
- The study was undertaken in order to find and scientifically validate the options for arsenic safewater in Bangladesh. The study has been carried out in a geological province where most of theshallow wells have arsenic above the allowable limit for drinking water according to Bangladeshstandard. The original study plan has been modified as newer information on arsenic mobilisationand mitigation was available. Accordingly the emphasis on dug well and arsenic removal filter hadbeen shifted to other options such as geologically targeted aquifers. Also at the same time therehas been collaboration with number of other projects been carried out in and around the studyarea. Eventually the main focus of the research was shifted to capacity development in order toenhance the local capability for finding safer sources drinking water in the study area and othersimilar environments in the country.
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| 6. |
- Bhattacharya, Prosun, 1962-, et al.
(author)
-
Arsenic in Swedish groundwater Mobility and risk for naturally elevated concentrations : Final Report
- 2010
-
Reports (other academic/artistic)abstract
- Arsenic (As) in groundwater has become a serious global problem during the last few decades forseveral reasons. The chronic toxicity from drinking water has motivated the lowering of thehealth limit from 50 μg/L to 10 μg/L. Due to the rather complicated analytical chemistry of As ithas seldom been analysed in groundwater. Once the common occurrence of excess As ingroundwater has been discovered like in Bangladesh it has become evident that As in concentrationswell above the health limit can be easily mobilized from very moderate amounts in the aquifermaterial under specific conditions. There are essentially three mechanisms of mobilization: 1)oxidation of sulphides containing As; 2) reduction of ferric compounds releasing adsorbed Asand 3) high pH conditions leading to lowered adsorption capacity of ferric and aluminium compounds. This study has aimed at investigating the mobilization of As under the conditions existing in Precambrianrocks and the overlying tills in Sweden. As study area the north-eastern part of theVästerbotten county was chosen. The occurrence of sulphides both in mineralisations and insome of the country rocks may infer that the risk of elevated As concentrations in groundwatermay be a bit higher there than elsewhere in Sweden. The hypothesis was that the two firstmechanisms mentioned above would be responsible for any elevated groundwater As in groundwater,thus either oxidation of sulphides or reducing conditions leading the reduction of ferrichydroxides. Samples were collected from drilled wells, dug wells and springs. pH, Eh and temperature weremeasured in the field and the samples were filtered through 0.20 m filters in the field. As(II) wasseparated from As(V) in the field by ion-exchangers. As redox conditions are the determinantsfor the mobilization of As the groundwaters have been classified into five redox classes followinga classification developed by the Swedish Environmental Protection Agency. Dug wells with elevatedAs turned out to be in the oxidizing part of the classification while drilled wells were foundin all classes. This is reasonable as drilled wells often collect water from different environmentsthrough the different fracture systems the drilled wells contact. Wetland springs are found tohave moderately reducing water high in iron. While drilled wells and dug wells show a wide spectrumof As(III)/As(tot) ratios the As(III) is clearly dominant in wetland springs. Drilled wellsshowed the highest concentrations of As up to 300 μg/L and wells drilled in alkaline volcanicrocks had the highest median concentrations of As. Arsenic in wetland springs were strongly correlatedto iron. Another clear relationship was that groundwater with even low concentrations ofnitrate was low in As. Obviously the presence of nitrate indicates an oxidizing environmentwhere As is firmly adsorbed onto ferric hydroxides. There was no clear relationship with sulphateindicating that the drilled wells which made up the majority of the groundwaters often had waterof a mixed origin coming to the well via different fracture systems. The results indicate that As should in general be analysed in household wells as it is difficult topredict the presence of elevated concentrations from the major ion chemistry. High iron concentrationis a factor that indicates an elevated risk of As above the health limit. Nitrate on the otherhand indicates a low risk for elevated As concentration.
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| 7. |
- Bhattacharya, Prosun, 1962-, et al.
(author)
-
Editors’ foreword
- 2016
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In: Arsenic Research and Global Sustainability. - London : CRC Press. - 9781315629438 ; , s. xlv-xlvi, s. xlvii-xlviii
-
Conference paper (peer-reviewed)
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| 8. |
- Bhattacharya, Prosun, 1962-, et al.
(author)
-
Hydrogeochemical contrasts across the multi-level aquifers of Bengal basin in Matlab, Bangladesh : Implications for arsenic free and low-manganese drinking water sources
- 2016
-
In: Arsenic Research and Global Sustainability - Proceedings of the 6th International Congress on Arsenic in the Environment, AS 2016. - : CRC Press/Balkema. ; , s. 45-46
-
Conference paper (peer-reviewed)abstract
- Targeting shallow, intermediate-deep and deep aquifers, piezometers nests were installed at 15 locations in the Matlab region, an As hotspot in southeastern Bangladesh. Groundwater levels and water quality were monitored for over a three years period. Stable isotopic composition was used to identify the hydrogeological characteristics of different aquifers, hydraulic connectivity between the contaminated and safe aquifers. Within the shallow depth (up to 100m), two aquifers (Aquifer-1 and Aquifer-2) were identified, and groundwater from Aquifer-1 indicated consistently high As concentration was found to be As-enriched (median As levels upto 714 μg/L). Considerable variability in As concentrations were observed in Aquifer-2 wells (6–30 μg/L) comprising relatively oxidized or less reduced red and off-white sands. The intermediate-deep and deep aquifers were found to contain very low As concentration and these aquifers are hydraulically separated from the shallow aquifers. Groundwater depth and elevation and stable isotope signatures also reflect that intermediate-deep and deep aquifers, in most places belong to the same hydrostratigraphic unit (Aquifer-3).
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| 9. |
- Bhattacharya, Prosun, 1962-, et al.
(author)
-
Natural Arsenic in Coastal Groundwaters in the Bengal Delta Region in West Bengal, India
- 2010
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In: Management and Sustainable Development of Coastal Zone Environments. - Dordrecht : Springer Netherlands. - 9789048130672 ; , s. 146-160
-
Book chapter (peer-reviewed)abstract
- Bengal Delta region is currently confronted with largest groundwater arsenic calamity in history of human kind (BGS-DPHE, 2001; Mukherjee and Bhattacharya, 2001; Bhattacharya et al., 2002a; McArthur et al., 2001; Smedley and Kinniburgh, 2002; Mukherjee et al., 2006; Nath et al., 2005, 2007, 2008). Concentrations of arsenic in drinking water wells in the region often exceed the WHO drinking water guideline value (10 μg L-1) and the national safe limit of both India and Bangladesh for arsenic in drinking water (Smedley and Kinniburgh, 2002; RGNDWM, 2002; CGWB, 1999; Bhattacharya et al., 2002a). About one third (35 million) population inhabiting in this region (West Bengal and Bangladesh), currently at risk of long-term arsenic exposure (Bhattacharya et al., 2001; RGNDWM, 2002; Chakraborti et al., 2004; Kapaj et al., 2006), are being diagnosed with a wide spectrum of adverse health impacts including skin disorders such as hyper/hypo-pigmentation, keratosis and melanosis and are also in hot-spot areas of BDP which is reflected in a rise in the number of cancer cases (Guha Mazumdar et al., 1988). The distribution pattern of arsenic occurrence in BDP is patchy and there are numerous hotspots of arsenic contamination in the semi-confined shallow Holocene aquifer (Bhattacharya et al., 1997; Smedley and Kinniburgh, 2002). The scale of the problem is serious both in terms of hotspots and geographic area coverage (173 × 10 3 km2, eastern part of Hoogly-Bhagirathi/Western part of Ganga-Padma-lower Meghna flood plains).
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| 10. |
- Bhattacharya, Prosun, 1962-, et al.
(author)
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Occurrence of arsenic-contaminated groundwater in alluvial aquifers from delta plains, eastern India: Options for safe drinking water supply
- 1997
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In: International Journal of Water Resources Development. - London, UK : Routledge. - 0790-0627 .- 1360-0648. ; 13:1, s. 79-92
-
Journal article (peer-reviewed)abstract
- Arsenic contamination in groundwater used for drinking purposes has been envisaged as a problem of global concern. Exploitation of groundwater contaminated with arsenic within the delta plains in West Bengal has caused adverse health effects among the population within a span of 8-10 years. The sources of arsenic in natural water are a function of the local geology, hydrology and geochemical characteristics of the aquifers. The retention and mobility of different arsenic species are sensitive to varying redox conditions. The delta plains in West Bengal are characterized by a series of meander belts formed by the fluvial processes comprising different cycles of complete or truncated fining upward sequences (sand-silt-clay). The arseniferous groundwater belts are mainly located in the upper delta plain and in abandoned meander channels. Mineralogical investigations have established that arsenic in the silty day as well as in the sandy layers occurs as coatings on mineral grains. Clayey sediments intercalated with sandy aquifers at depths between 20 and 80 m are reported as a major source of arsenic in groundwater. Integrated knowledge on geological, hydrological and geochemical characteristics of the multi-level aquifer system of the upper delta plain is therefore necessary in predicting the origin, occurrence and mobility of arsenic in groundwater in West Bengal. This would also provide a basis for developing suitable low-cost techniques for safe drinking water supply in the region.
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