| 1. |
- Ahmad, A., et al.
(författare)
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Arsenic removal to <1 µg l−1 by coprecipitation with in-situ generated Fe(III) precipitates with and without advanced pre-oxidation
- 2018
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Ingår i: Environmental Arsenic in a ChangingWorld - 7th International Congress and Exhibition Arsenic in the Environment, 2018. - London : CRC Press/Balkema. - 9781138486096 ; , s. 591-592
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Konferensbidrag (refereegranskat)abstract
- The aim of this study is to investigate removal of low As concentrations from groundwater at a Drinking Water Treatment Plant (DWTP) in The Netherlands in order to achieve <1 µg L−1 As in produced drinking water. Two iron based emerging technologies, both relying on in-situ generated Fe(III) precipitates for As adsorption, were investigated. These include: 1) Advanced Oxidation-Coprecipitation-Filtration (AOCF) and 2) Coprecipitation prior to ultrafiltration (C-UF). We show that most of the As removal occurs in the top half of a Rapid Sand Filter (RSF) bed. In this part we also observe the conversion of As(III) into As(V). The mechanism of As(III) oxidation to As(V) in the RSF is still not understood, however we hypothesize that either the manganese oxides or the biological activity in the filter bed may be responsible for this conversion. In agreement with this observation, we also notice that drinking water only contains As(V) and that the levels of As(III) are negligible. The experiments have shown that both AOCF and C-UF are promising emerging technologies to reduce arsenic levels to below 1 µg L−1 which is the agreed target in The Netherlands between the Dutch water companies.
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| 2. |
- Ahmed, K. M., et al.
(författare)
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Implementation of arsenic mitigation : Insights from Araihazar and Matlab – two extensively studied areas in Bangladesh
- 2018
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Ingår i: Environmental Arsenic in a ChangingWorld - 7th International Congress and Exhibition Arsenic in the Environment, 2018. - London : CRC Press/Balkema. - 9781138486096 ; , s. 565-566
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Konferensbidrag (refereegranskat)abstract
- Despite many efforts over the last 25 years, millions of people are still drinking groundwater having arsenic above Bangladesh and World Health Organization limits. This can be linked, to some extent, to a lack of pragmatic policies and implementation strategies. Important lessons have been learned from extensive studies in Araihazar and Matlab in Bangladesh. Also better mitigation strategies for reducing arsenic exposure have been demonstrated at both locations. New policy and mitigation strategies should focus on mapping using mobile technology for village scale mapping. Dissemination of test result is extremely important in increasing awareness of the users and a new three-color scheme (Blue, Green, Red corresponding to <10, 10–50, and >50 µg L−1) instead of existing Red-Green color scheme should be adopted to lower arsenic intake. Safe wells can be installed at appropriate locations and depth by combining hydrogeological and social criteria aided by applications-based score ranking.
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| 3. |
- Battaglia-Brunet, F., et al.
(författare)
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Characterization of an agricultural site historically polluted by the destruction of arsenic-containing chemical weapons
- 2018
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Ingår i: Environmental Arsenic in a ChangingWorld - 7th International Congress and Exhibition Arsenic in the Environment, 2018. - London : CRC Press/Balkema. - 9781138486096 ; , s. 241-242
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Konferensbidrag (refereegranskat)abstract
- Arsenic in agricultural soils may represent a risk for crop quality and surrounding water resources. In the frame of AgriAs project, “Evaluation and management of Arsenic contamination in agricultural soil and water”, a former chemical weapons destruction site converted into agricultural land was characterized. The objective of this study was to identify possible links between arsenic concentration and speciation and bioindicators informing about the bioavailability of the toxic element. Plants lipidic bio-indicator Omega-3 Index showed that toxicity of the soil was not directly correlated with arsenic concentration. Conversely, arsenic level in the soil samples seemed to influence the density of microbes transforming As species.
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| 4. |
- Chakraborty, M., et al.
(författare)
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Identifying the arsenic-safe aquifers of the Ganges Delta : Some insights into sustainable aquifer management
- 2018
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Ingår i: Environmental Arsenic in a ChangingWorld - 7th International Congress and Exhibition Arsenic in the Environment, 2018. - London : CRC Press/Balkema. - 9781138486096 ; , s. 627-628
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Konferensbidrag (refereegranskat)abstract
- The widespread health impacts on millions of people from consumption of arsenic (As) contaminated groundwater of the Ganges delta necessitate an effort to locate As-safe aquifer zones and to develop a sustainable aquifer management policy. We look into the aquifer geometries, sediment characteristics and groundwater As concentrations to develop an understanding of the factors that inhibit As invasion/mobilization within the As-safe aquifers. However, the sustainability of the present-day safe aquifer is at risk due to the heavy groundwater pumping for irrigation and thus, promoting water conserving agricultural practices is extremely vital. We suggest that, formulating a sustainable As mitigation plan should also involve the non-scientific communities such as the local tubewell drillers and farmers for widespread implementation of the plan.
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| 5. |
- Ghosh, D., et al.
(författare)
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Translocation of arsenic in food chain: A case study from villages in Gangetic basin, India
- 2018
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Ingår i: ENVIRONMENTAL ARSENIC IN A CHANGING WORLD (AS2018). - : CRC PRESS-BALKEMA. - 9781351046633 - 9781138486096 ; , s. 303-304
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Konferensbidrag (refereegranskat)abstract
- Arsenic (As) contamination of groundwater is a worldwide concern and West Bengal in India is affected by this problem. Different food crops may accumulate As differently, and studies often show conflicting results. A previous study from Karimpur block, Nadia district, West Bengal indicated high concentration of As in two tube wells. Groundwater from these wells is used for irrigating nearby agricultural fields. The aim of this study was therefore to analyze As and other metals concentration in different vegetables and rice growing in these fields. In addition, animal fodder plants and cow milk was also analyzed to investigate the possibility of transfer of arsenic through food chain. The samples were analyzed using a microwave digestion procedure followed by inductively coupled plasma mass spectrometry. Animal fodder roots showed high concentration of As compared to other samples. The results also showed possible translocation of Cd along with As from root to shoot, in animal fodder. The milk samples showed high concentrations of As and Pb.
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| 6. |
- Herath, I., et al.
(författare)
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Sulfur-arsenic interactions and formation of thioarsenic complexes in the environment
- 2018
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Ingår i: Environmental Arsenic in a ChangingWorld - 7th International Congress and Exhibition Arsenic in the Environment, 2018. - London : CRC Press/Balkema. - 9781138486096 ; , s. 210-211
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Konferensbidrag (refereegranskat)abstract
- Thiolated arsenic compounds are the sulfur analogous substructures of oxo-arsenicals as the arsinoyl (As=O) is substituted by an arsinothioyl (As=S) group. Relatively brief history of thioarsenic research, mostly in the current decade has endeavored to understand their consequences in the natural environment. However, thioarsenic related aspects have by far not attached much research concern on global scale compared to other arsenic species. This paper provides a critical overview on formation mechanisms of thioarsenicals and their chemistry aiming to direct future research towards thioasenic mitigation strategies. Sulfur-arsenite/arsenate interactions and dissolution of arsenic sulfide minerals are the main mechanisms that involve in the formation of different thioarsenic species in the natural environment. The formation and chemical analysis of thioarsenicals in soil and sediments are highly unknown. Future research needs to be more inclined towards in determining the molecular structure of unknown thioarsenic complexes in various environmental suites.
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| 7. |
- Ijumulana, Julian, et al.
(författare)
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Potential arsenic contamination in drinking water sources of Tanzania and its link with local geology
- 2018
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Ingår i: Environmental Arsenic in a ChangingWorld - 7th International Congress and Exhibition Arsenic in the Environment, 2018. - London : CRC Press/Balkema. - 9781138486096 ; , s. 62-63
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Konferensbidrag (refereegranskat)abstract
- Recent studies on arsenic (As) occurrence particularly inAfrican waters show that several sources of drinking water have elevated concentrations above national and international guidelines. In Tanzania, elevated concentrations of As above the WHO guideline (10 µg L−1) in Lake Victoria Gold fields is emerging as a threat to public health depending on groundwater and surface water as drinking water sources. In this study, spatial statistics and GIS tools have been used to delineate the relationship between As occurrence and local geological settings. Among the 12 mapped local geological units, the most targeted aquifers for potable water are characterized by granitoids, migmatite, mafic and ultramafic meta-sediments (~50% of water points). The probability of having As levels above the WHO guideline was 0.71 and 0.33 for surface water and groundwater systems respectively.
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| 8. |
- Irunde, Regina, et al.
(författare)
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Visual MINTEQ simulation for prediction of the adsorption of arsenic on ferrihydrite
- 2018
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Ingår i: Environmental Arsenic in a ChangingWorld - 7th International Congress and Exhibition Arsenic in the Environment, 2018. - London : CRC Press/Balkema. - 9781138486096 ; , s. 435-436
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Konferensbidrag (refereegranskat)abstract
- The surface of ferrihydrite adsorbs arsenic (As) effectively. In this investigation, the As laced water samples collected from Geita and Mara regions within the Lake Victoria Basin (LVB) under DAFWAT project were simulated onVisual MINTEQ 3.1 software to determine the amount of ferrihydrite required to adsorb a given amount of As from water. Model simulations show that As concentration of ≤1 mM can be completely adsorbed by 4 g L−1 ferrihydrite. Previous studies show that the lower pH 4 to 4.5 influences adsorption, while it decreases as pH increases as well as when As concentration increases. The increase of adsorbent dose to 4 g L−1 has shown to improve As(V) adsorption on pH 5 to 8 at 100%. The amount of adsorbent can now be used for laboratory adsorption experiments by using iron-based materials or commercial ferrihydrite.
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| 9. |
- Jacks, G., et al.
(författare)
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Arsenic and trace metal mobility in alum shale areas in Sweden
- 2018
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Ingår i: Environmental Arsenic in a ChangingWorld - 7th International Congress and Exhibition Arsenic in the Environment, 2018. - London : CRC Press/Balkema. - 9781138486096 ; , s. 196-197
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Konferensbidrag (refereegranskat)abstract
- Alum shales found in Sweden are enriched in As and trace metals like Mo, Zn, Cd, Ni and U with the redox conditions being crucial for the mobilization of those elements. The shales have been mined, e.g. for uranium. Uranium is mobilized under oxidizing conditions, while arsenic is mobilized under reducing conditions. This plays a role under natural conditions in the alum shale but more so in the tailings after mining. An investigation of a natural area indicates small environmental risks while the utilization of the shales has left tailings that tend to leak into the environment.
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| 10. |
- Jeworrek, A., et al.
(författare)
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Reduction of low arsenic concentrations in drinking water to below 1 µg L−1 by adsorption onto granular iron (Hydr)oxides
- 2018
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Ingår i: Environmental Arsenic in a ChangingWorld - 7th International Congress and Exhibition Arsenic in the Environment, 2018. - London : CRC Press/Balkema. - 9781138486096 ; , s. 593-594
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Konferensbidrag (refereegranskat)abstract
- Arsenic in drinking water should be reduced as much as possible, because it is amongst carcinogenic substances. FerroSorp® Plus, Huijbergen and Spannenburg GIH could reduce As(V) levels in Ouddorp water below the desired 1 µg L−1. Particularly Huijbergen GIH had according to non-linear Freundlich modeling the higher KF value, translating into a potentially higher effective adsorption capacity. One of the characteristics that probably determines the success of a GIH is its physical properties. Since the effective adsorption capacity increases with higher initial As(V) concentrations, Huijbergen GIH is a promising adsorbent to reduce a wide range of arsenic concentrations from drinking water. Therefore, this affordable technology is not only reducing ultra-low arsenic concentrations to even lower concentrations in Ouddorp water but is also promising for developing countries that are seriously affected by high concentrations of arsenic in their drinking water.
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