Iron-based subsurface arsenic removal (SAR): Results of a long-term pilot-scale test in Vietnam
| Autor: | Vu T. Luong, Edgardo E. Cañas Kurz, U. Hellriegel, Felix Leidinger, Jochen Bundschuh, Jan Hoinkis, Tran Le Luu |
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| Rok vydání: | 2019 |
| Předmět: |
Environmental Engineering
Iron 0208 environmental biotechnology Zero waste chemistry.chemical_element Aquifer 02 engineering and technology Manganese 010501 environmental sciences 01 natural sciences law.invention Arsenic Water Purification Adsorption law Waste Management and Disposal Groundwater Filtration 0105 earth and related environmental sciences Water Science and Technology Civil and Structural Engineering geography geography.geographical_feature_category Ecological Modeling Pollution Anoxic waters 020801 environmental engineering chemistry Vietnam Environmental chemistry Environmental science Water Pollutants Chemical |
| Zdroj: | Water research. 181 |
| ISSN: | 1879-2448 |
| Popis: | The principle of subsurface arsenic removal (SAR) from groundwater is based on oxidation and adsorption reactions by infiltrating oxygen into the anoxic aquifer and the immobilization of arsenic (As) onto freshly formed iron (Fe)-(hydr)oxides. In this study, a pilot-scale plant for SAR has been subject to long term testing in the Mekong Delta, Vietnam. Initial concentrations of Fe (8.4 ± 1.3 mg L−1) and As (81 ± 8 μg L−1) in the exploited groundwater were successfully lowered to below the WHO guideline value limits for drinking water of 0.3 mg L−1 and 10 μg L−1, respectively. Adsorption and co-precipitation of As with Fe-(hydr)oxides could be identified as the principal mechanism responsible for the As removal from groundwater, demonstrating the feasibility of SAR as a low-cost and zero-waste solution over a period of two years. However, naturally occurring geochemical reducing conditions and high ammonium levels in the groundwater delayed the removal of manganese (Mn). An additional post-treatment filtration for Mn-removal was temporarily used to comply with the Vietnamese drinking water standard until a Mn-mitigation was achieved by the SAR process. In contrast to most As-remediation technologies, SAR appears to be a long-term, sustainable treatment option with the salient advantage of negligible production of toxic waste, which with ex-situ processes require additionally management costs. |
| Databáze: | OpenAIRE |
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