| 1. |
- Maity, J. P., et al.
(författare)
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Advanced application of nano-technological and biological processes as well as mitigation options for arsenic removal
- 2021
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Ingår i: Journal of Hazardous Materials. - : Elsevier BV. - 0304-3894 .- 1873-3336. ; 405
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Tidskriftsartikel (refereegranskat)abstract
- Arsenic (As) removal is a huge challenge, since several million people are potentially exposed (>10 μg/L World Health Organization guideline limit) through As contaminated drinking water worldwide. Review attempts to address the present situation of As removal, considering key topics on nano-technological and biological process and current progress and future perspectives of possible mitigation options have been evaluated. Different physical, chemical and biological methods are available to remove As from contaminated water/soil/wastes, where removal efficiency mainly depends on absorbent type, initial adsorbate concentration, speciation and interfering species. Oxidation is an important pretreatment step in As removal, which is generally achieved by several media such as O2/O3, HClO, KMnO4 and H2O2. The Fe-based-nanomaterials (α/β/γ-FeOOH, Fe2O3/Fe3O4–γ-Fe2O3), Fe-based-composite-compounds, activated-Al2O3, HFO, Fe-Al2O3, Fe2O3-impregnated-graphene-aerogel, iron-doped-TiO2, aerogel-based- CeTiO2, and iron-oxide-coated-manganese are effective to remove As from contaminated water. Biological processes (phytoremediation/microbiological) are effective and ecofriendly for As removal from water and/or soil environment. Microorganisms remove As from water, sediments and soil by metabolism, detoxification, oxidation-reduction, bio-adsorption, bio-precipitation, and volatilization processes. Ecofriendly As mitigation options can be achieved by utilizing an alternative As-safe-aquifer, surface-water or rainwater-harvesting. Application of hybrid (biological with chemical and physical process) and Best-Available-Technologies (BAT) can be the most effective As removal strategy to remediate As contaminated environments.
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| 2. |
- Maity, J. P., et al.
(författare)
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Hydrogeochemical reconnaissance of arsenic cycling and possible environmental risk in hydrothermal systems of Taiwan
- 2017
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Ingår i: Groundwater for Sustainable Development. - : Elsevier. - 2352-801X. ; 5, s. 1-13
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Tidskriftsartikel (refereegranskat)abstract
- Hydrothermal activity creates geo-hydro-chemical interactions between hot water/fluid and the host rocks, which changes the hydro-chemical composition of the geothermal water/fluid and enriches trace elements. Existence of arsenic (As) is reported from different hydrothermal systems as well as several region in groundwater system at elevated concentration globally, compared to 10 μg/L WHO (World health Organization) guideline. The distribution of dissolved major and minor elements, including arsenic (As) was studied in hydrothermal systems of Taiwan. For the first time in Taiwan As(V) and As(III) species were researched from the three principal geological settings of Taiwan. Aim was to understand the cycling, fate and transport and potential impact of As on the surficial hydrological systems. Water samples were collected from sixteen hydrothermal springs of 3 different geological settings. Three groups of hydrothermal spring water samples could be distinguished: (i) strongly acidic (pH<3), sulfate-enriched waters of H-SO4-type (Yangmingshan, and Taipu, Beitou), (ii) slightly alkaline waters (pH: 8–8.95) (Jiben, Antung and Kung-Tzu-Ling), and (iii) circum-neutral waters (pH 6.47–7.41) of Na-HCO3/Na-Cl-HCO3-type (Wulai, Hongye, Rueisuei, Chung-Lun and Biolai). The waters are enriched with alkali and alkali earth metals compared to drinking water. Similarly, the water of most of the geothermal springs were found to be enriched with As (highest concentration at Beitou: 1.456 mg/L) with As(III) being the principal As species. Arsenic concentrations of hydrothermal spring waters in igneous rock terrains exhibit highest concentrations (0.69±0.71 mg/L) followed by those of sedimentary (0.16±0.14 mg/L) and metamorphic (0.06±0.02 mg/L) terrains. The discharged geothermal springs water contaminate the surface and groundwater (including drinking and irrigation water resources), where significant levels of arsenic and other toxic element have detected and hence being a significant risk for human health and environmental.
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| 3. |
- Maity, J. P., et al.
(författare)
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Investigation of arsenic contamination from geothermal water in different geological settings of Taiwan : Hydrogeochemical and microbial signatures
- 2016
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Ingår i: Arsenic Research and Global Sustainability - Proceedings of the 6th International Congress on Arsenic in the Environment, AS 2016. - : CRC Press/Balkema. - 9781138029415 ; , s. 84-85
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Konferensbidrag (refereegranskat)abstract
- The dissemination of dissolved elements, including arsenic (As(V)/As(III)) and microbial diversity was studied in hydrothermal systems of Taiwan considering three different principal geological settings such as Igneous rock terrains, Metamorphic terrains and Sedimentary terrains to understand the cycling, fate and transport and potential impact of As on hydrological systems. The results were indicated as strongly acidic (pH< 3), sulfate-enriched waters of H-SO4-type in igneous-sedimentary rock terrains, slightly alkaline waters (pH: 8–8.95) in metamorphic terrains, and circum-neutral waters (pH 6.47–7.41) of Na-HCO3/Na-Cl-HCO3-type in metamorphic-sedimentary terrains. The geothermal waters were enriched with As in igneous terrains (Beitou: 1.46 mg/L) as compared to sedimentary (0.16 ± 0.14 mg/L) or metamorphic (0.06 ± 0.02 mg/L) terrains. The 16S rRNA gene sequence of bacterial diversity indicates prevalence of mesophilic sulfur- and thiosulfate-oxidizing bacterium in Taipu (igneous rock terrains). The discharge from geothermal springs with significant levels of As and other toxic element contaminate the surface and groundwater of environment.
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