Homogeneous, heterogeneous and biological oxidation of iron(II) in rapid sand filtration

Abstract

Research Article| February 01 2012 Homogeneous, heterogeneous and biological oxidation of iron(II) in rapid sand filtration C. G. E. M. van Beek; C. G. E. M. van Beek 1KWR Watercycle Research Institute, PO Box 1072, 3430 BB Nieuwegein, The Netherlands E-mail: Kees.van.Beek@kwrwater.nl Search for other works by this author on: This Site PubMed Google Scholar T. Hiemstra; T. Hiemstra 2Wageningen University, Department of Soil Quality, PO Box 47, 6700 AA Wageningen, The Netherlands Search for other works by this author on: This Site PubMed Google Scholar B. Hofs; B. Hofs 1KWR Watercycle Research Institute, PO Box 1072, 3430 BB Nieuwegein, The Netherlands Search for other works by this author on: This Site PubMed Google Scholar M. M. Nederlof; M. M. Nederlof 1KWR Watercycle Research Institute, PO Box 1072, 3430 BB Nieuwegein, The Netherlands Search for other works by this author on: This Site PubMed Google Scholar J. A. M. van Paassen; J. A. M. van Paassen 3Water utility Vitens, PO Box 1090, 8200 BB Lelystad, The Netherlands Search for other works by this author on: This Site PubMed Google Scholar G. K. Reijnen G. K. Reijnen 4Water utility WML, PO Box 1060, 6201 BB Maastricht, The Netherlands Search for other works by this author on: This Site PubMed Google Scholar Journal of Water Supply: Research and Technology-Aqua (2012) 61 (1): 1–13. https://doi.org/10.2166/aqua.2012.033 Article history Received: May 03 2011 Accepted: November 15 2011 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Cite Icon Cite Permissions Search Site Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsThis Journal Search Advanced Search Citation C. G. E. M. van Beek, T. Hiemstra, B. Hofs, M. M. Nederlof, J. A. M. van Paassen, G. K. Reijnen; Homogeneous, heterogeneous and biological oxidation of iron(II) in rapid sand filtration. Journal of Water Supply: Research and Technology-Aqua 1 February 2012; 61 (1): 1–13. doi: https://doi.org/10.2166/aqua.2012.033 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Homogeneous, heterogeneous and biological oxidation may precipitate iron(II) as iron(III) hydroxides. In this paper we evaluate the conditions under which each of these processes is dominant in rapid sand filtration (RSF). It is demonstrated that in the presence of iron(III) hydroxide precipitates homogeneous oxidation is negligible compared with heterogeneous oxidation. As soon as iron oxidizing bacteria (IOB) are present, biological oxidation may contribute substantially, in particular under conditions of slight acidity and low oxygen concentration. As the oxidation step is preceded by an adsorption/uptake step, the competition between heterogeneous and biological oxidation is not determined by the oxidation rate, but by the adsorption or uptake rate. Extracellular polymeric substance (EPS), excreted by all kinds of bacteria, may serve as an initial adsorbent for dissolved iron(II) and iron(III) hydroxides. Because adsorption and oxidation of iron (II) either on biofilms (or EPS) or on mineral surfaces, are chemical processes, ‘EPS iron oxidation’ is not considered as a biological process. The so-called ‘biological iron oxidation’ actually refers to a treatment method characterized by high filtration rates and limited oxygen supply, where iron(II) is removed mainly by heterogeneous oxidation. The contribution of oxidation of iron(II) by IOB in this method is variable and may even be absent. drinking water, groundwater, hydrous ferric oxides, iron(II) oxidation, iron removal, rapid sand filtration This content is only available as a PDF. © IWA Publishing 2012 You do not currently have access to this content.