Nitrate reduction by mixed iron(II-III) hydroxycarbonate green rust in the presence of phosphate anions: the key parameters influencing the ammonium selectivity
| Autor: | Brian Grégoire, Asfaw Zegeye, Marjorie Etique, Cédric Carteret, Christian Ruby |
|---|---|
| Přispěvatelé: | Laboratoire de Chimie Physique et Microbiologie pour l'Environnement (LCPME), Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL), Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC), Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Terre et Environnement de Lorraine (OTELo), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC) |
| Rok vydání: | 2014 |
| Předmět: |
inorganic chemicals
Anions Environmental Engineering Denitrification Iron Kinetics Inorganic chemistry Carbonates Fraction (chemistry) Phosphates chemistry.chemical_compound Nitrate Ammonium Compounds Ammonium [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment Waste Management and Disposal ComputingMilieux_MISCELLANEOUS Water Science and Technology Civil and Structural Engineering Nitrates Ecological Modeling Phosphate Pollution [SDE.ES]Environmental Sciences/Environmental and Society 6. Clean water chemistry [SDE]Environmental Sciences Selectivity Saturation (chemistry) Oxidation-Reduction |
| Zdroj: | Water Research Water Research, IWA Publishing, 2014, 62, pp.29-39. ⟨10.1016/j.watres.2014.05.028⟩ |
| ISSN: | 1879-2448 0043-1354 |
| DOI: | 10.1016/j.watres.2014.05.028⟩ |
| Popis: | International audience; The reduction of nitrate anions by a mixed Fe-II-Fe-III carbonated green rust (GR) in aqueous medium is studied as a function of the initial pH and the initial concentrations of iron, phosphate and nitrate. The influence of these parameters on the fraction of nitrate removed and the production of ammonium is investigated by the help of statistical experimental designs. The goal is to determine experimental conditions that maximize the fraction of NO3- removed and concomitantly minimize the production of NH4+. Increasing the phosphate concentration relatively to the initial Fe-II concentration inhibits the reduction of nitrate probably due to a surface saturation of the lateral sites of the GR crystals. The kinetics of the reaction is greatly enhanced by increasing the initial pH at 10.5, however it leads to a global increase of the NH4+ production. A partial saturation of the surface sites by phosphate leads to a global decrease of selectivity of the reaction towards ammonium. The evolution of the ratio of the NH4+ concentration to the Fe-II concentration confirms that the NO3- species are only partially transformed into ammonium. Interestingly at an initial pH of 7.5, the selectivity of the reaction towards NH4+ is often lower than similar to 30%. The reduction of nitrate by carbonated GR differs from the behavior of other GRs incorporating Cl-, F- and SO42- anions that fully transform nitrate into ammonium. Finally, if GR is intended to be used during a passive water denitrification process, complementary dephosphatation and ammonium treatments should be considered. (C) 2014 Elsevier Ltd. All rights reserved. |
| Databáze: | OpenAIRE |
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