| 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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| 11. |
- Jones-Johansson, C., et al.
(författare)
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Assessment of environmental and health risks of arsenic in agricultural soils
- 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. 559-560
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Konferensbidrag (refereegranskat)abstract
- Within the framework of the AgriAs project, assessment of risks to health and the environment from arsenic in the agricultural soils and recipient water bodies is being carried out. Criteria for risk assessment from different organizations and countries have been collated, and an exposure model for arsenic in agricultural soils is being developed. The exposure model will be applied to assess the present-day situation at two test sites where elevated arsenic concentrations are found in agricultural soil. The model will also be used to assess the risk reduction achieved by proposed methods of amelioration and treatment.
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| 12. |
- Kasiuliene, Alfreda, et al.
(författare)
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Iron coated peat as a sorbent for the simultaneous removal of arsenic and metals from contaminated water
- 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. 439-440, s. 439-440
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Konferensbidrag (refereegranskat)abstract
- This study aimed at combining peat, an industrial residue, with Fe(II)-Fe(III) compound to produce a sorbent suitable for a simultaneous removal of arsenic (As) and metals (cadmium, copper, nickel, lead, zinc) from a contaminated water. Using a newly produced sorbent – iron-peat – the removal of As from contaminated water was almost 17 times higher than using an uncoated peat. On the other hand, the removal of metals by the iron-peat was slightly less efficient in comparison to the uncoated peat. Simultaneous removal of As and metals could be seen as an advantage over multiple-step treatment of contaminated groundwater.
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| 13. |
- Korevaar, M. W., et al.
(författare)
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Modeling arsenic removal by co-precipitation under variable redox conditions
- 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. 432-434
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Konferensbidrag (refereegranskat)abstract
- Drinking water companies in the Netherlands are actively investigating routes to reduce arsenic (As) to <1 µg L−1 in drinking water. Co-precipitation of As with iron during groundwater treatment is a promising method. When As(III) is present in raw water, permanganate (MnO4) can be dosed to oxidize As(III) to As(V) in order to improve As removal efficiency. The dosages of MnO4 and Fe(III) to achieve <1 µg L−1 As in the treatment effluents depend on the composition of raw water. The coprecipitation of As(III) and As(V) with ferrihydrite under variable raw water composition and redox environments, controlled by oxygen (O2) or MnO4 is modeled in this study by the generalized double layer model, and redox equilibrium reactions. Results show that the pH of the treatment process is critical to determine the As removal efficiency. At pH = 8 the highest As removal is obtained, followed by pH = 6 while pH = 7 gives the least removal. HCO3, PO4 and H4 SO4 hamper the adsorption of As(V). In future work, the model outcome will be assessed by experiments. Furthermore, the model will be extended with oxidation kinetics in case oxidation (by e.g. oxygen) occurs at a slower rate than the (mean) residence time of the water in the process.
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| 14. |
- Onabolu, B., et al.
(författare)
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Integrating policy, system strengthening, research and harmonized services delivery for scaling up drinking water safety 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. 535-537
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Konferensbidrag (refereegranskat)abstract
- The WASH Sector Development Plan (2011–2025) recognizes the absence of harmonized approaches as the root challenge to scaling up drinking water safety in Bangladesh. UNICEF is supporting the Government of Bangladesh (GoB) through the Department of Public Health Engineering (DPHE) and Policy Support Branch to re-engineer its approach to drinking water safety by integrating policy, systems strengthening & sustainable services delivery at national and sub-national levels. Some of the key contributions to the sector include the implementation of the UNICEF-DPHE Arsenic Safe Union model with the declaration of 106 Arsenic Safe Villages, reduction in arsenic contamination rates of new tubewells, a system for preventing elite capture of water points, and the adoption of the ASU model in a $240 million arsenic mitigation drinking water project using domestic resources. Relatedly, a Policy Support Branch has been established, the sector coordination mechanisms revised, WASH bottleneck analysis is ongoing & the National Implementation Plan on Arsenic has been reviewed: Next steps include the professionalisation of drilling by local drillers through a partnership with KTH, Sweden, the GoB and UNICEF.
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| 15. |
- Quino Lima, Israel, Doctoral student, 1980-, et al.
(författare)
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Spatial variability of trace elements with Moran’s i analysis for shallow groundwater quality in the Lower Katari Basin, Bolivian Altiplano
- 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. 64-65
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Konferensbidrag (refereegranskat)abstract
- The southeastern part of the Titicaca Lake near the Cohana Bay in the Bolivian Altiplano, has environmental problems caused mainly by urban and industrial wastes upstream of the Katari Basin and by natural geological conditions. This environmental condition has generated an increase in the concentrations of some trace elements in the groundwater. The Moran’s I statistic was used with LISA (Local Indicators of Spatial Association) method to know the spatial autocorrelation and the spatial variability of As, Sb, B, Al, Mn and F. Arsenic and antimony are the main pollutants due to natural geological conditions and boron due to the anthropogenic activities. Almost half of all the shallow groundwater samples exceeded the WHO and NB-512 guideline values mainly for antimony, boron and arsenic, whereby the spatial distribution of these trace elements in groundwater raises a significant concern about drinking water quality.
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| 16. |
- Sharma, S., et al.
(författare)
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ASMITAS – A novel application for digitalizing the SASMIT Sediment Color Tool to identify arsenic safe aquifers for drinking water supplies
- 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. 629-632
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Konferensbidrag (refereegranskat)abstract
- Arsenic (As) contamination in groundwater is an environmental health hazard in several part of the world and a large number of population has affected due to its toxic nature. In Bangladesh, a comprehensive research was accomplished which established a very strong correlation between the aquifer sediments and As concentration in the groundwater. The local drillers practice this knowledge over a time. Based on an action research conducted by the SASMIT project team from KTH Royal Institute of Technology, Sweden in collaboration with the local drillers in Bangladesh and a novel handheld sediment color tool was produced to facilitate the local drillers to target safe aquifers for safe tube-well installation. This study was made to advance this tool to be developed as a fully artificial intelligence (AI) based digital ASMITAS (Arsenic Mitigation at Source) tool based on spectral scanning of the sediment color. An HSI camera enables us to capture continuous spectral channels from a given object ranging from IR bands, through VR to UV ranges and hence scores comprehensive imaging output over traditional RGB data based color cameras, thus increase the perception of the color with more accuracy and precision. This new tool can be scalable to cover large geographical area and hence can be very useful tool for local drillers and other stakeholders for smart decision making for installation of safe tube-wells for mitigating As at source level.
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| 17. |
- van der Wens, P., et al.
(författare)
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Integrating arsenic in water safety planning in the Netherlands
- 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. 618-619
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Konferensbidrag (refereegranskat)abstract
- The Dutch drinking water sector complies with the most restrictive guidelines in the world and has a long-standing history of striving for excellence in water quality standards. The Dutch Association of Drinking Water Companies (Vewin) concluded in 2015 to lower the standard on arsenic in drinking water to 1 µg L−1. Following the new recommendation Brabant Water, a major water supply company in The Netherlands developed its masterplan on arsenic reduction by analysing the presence of arsenic in the systems from source to tap. Several measures were put in place to integrate arsenic into water safety planning in order to manage the risks. The underlying cost-benefit study and its implication on water safety planning at Brabant Water is discussed in this presentation.
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| 18. |
- van Halem, D., et al.
(författare)
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Small-scale piped water supply : End-user inclusive water research in arsenic affected areas in India and Bangladesh (DELTAP)
- 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. 636-637
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Konferensbidrag (refereegranskat)abstract
- DELTAP is a multi-disciplinary research project, where geologists, water treatment scientists and industrial design engineers join forces to develop an integrated approach towards small-scale piped water supply (SPWS) systems in the arsenic-affected Ganges-Brahmaputra-Meghna Delta. The project has started in 2016 with a field study in Bihar (India) with a focus on water quality mapping with mobile crowd participation. The coming years the research will continue with 3 PhD candidates, both in India and Bangladesh, with the ultimate aim to develop blueprints for end-user inclusive SPWS systems.
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