Print Email Facebook Twitter Identification of iron and sulfate release processes during riverbank filtration using chemical mass balance modeling Title Identification of iron and sulfate release processes during riverbank filtration using chemical mass balance modeling Author An, Seongnam (Korea Institute of Science and Technology; Korea University) Kang, Peter K. (University of Minnesota Twin Cities) Stuyfzand, Pieter Jan (TU Delft Geo-engineering; KWR Water Cycle Research Institute) Lee, Woonghee (University of Minnesota Twin Cities) Park, Saerom (Korea Institute of Civil Engineering and Building Technology (KICT)) Yun, Seong Taek (Korea University) Lee, Seunghak (Korea Institute of Science and Technology; Korea University) Date 2021 Abstract Various hydrogeochemical processes can modify the quality of river water during riverbank filtration (RBF). Identifying the subsurface processes responsible for the bank-filtered water quality is challenging, but essential for predicting water quality changes and determining the necessity of post-treatment. However, no systematic approach for this has been proposed yet. In this study, the subsurface hydrogeochemical processes that caused the high concentrations of total iron (Fe) and sulfate (SO42−) in the bank-filtered water were investigated at a pilot-scale RBF site in South Korea. For this purpose, water quality variations were monitored in both the extraction well and the adjacent river over five months. The volumetric mixing ratio between the river water and the native groundwater in the RBF well was calculated to understand the effect of mixing on the quality of water from the well and to assess the potential contribution of subsurface reactions to water quality changes. To identify the subsurface processes responsible for the evolution of Fe and SO42− during RBF, an inverse modeling based on the chemical mass balance was conducted using the water quality data and the calculated volumetric mixing ratio. The modeling results suggest that pyrite oxidation by abundant O2 present in an unsaturated zone could be a primary process explaining the evolution of total Fe and SO42− during RBF at the study site. The presence of pyrite in the aquifer was indirectly supported by iron sulfate hydroxide (Fe(SO4)(OH)) detected in oxidized aquifer sediments. Subject Chemical mass balanceInverse modelingIronRiverbank filtrationSulfate To reference this document use: http://resolver.tudelft.nl/uuid:baa06bd2-08e1-4bb4-a591-6d8c9cf02aee DOI https://doi.org/10.1007/s10653-021-00850-0 Embargo date 2022-02-13 ISSN 0269-4042 Source Environmental Geochemistry and Health: official journal of the Society for Environmental Geochemistry and Health, 43 (9), 3583-3596 Bibliographical note Accepted author manuscript Part of collection Institutional Repository Document type journal article Rights © 2021 Seongnam An, Peter K. Kang, Pieter Jan Stuyfzand, Woonghee Lee, Saerom Park, Seong Taek Yun, Seunghak Lee Files PDF EGAH_pre_publication_ver.pdf 683.5 KB Close viewer /islandora/object/uuid:baa06bd2-08e1-4bb4-a591-6d8c9cf02aee/datastream/OBJ/view