title: Effect of aging on phosphorus speciation in surface deposit of a vertical flow constructed wetland.
abstract: This study was conducted to determine phosphorus (P) species captured in a vertical-flow constructed wetland (VFCW) system combining a trickling filter followed by FeCl3 injection for phosphate coagulation. Suspended solids (SS) thus formed accumulated over time at the VFCW surface and transformed into a sludge deposit layer, which was shown to concentrate most of the P captured in the system. In order to investigate the effect of aging on P species, representative SS and sludge samples were taken from a wastewater treatment plant that had been in operation for 8 years and analyzed using P fractionation, solution (31)P NMR spectroscopy, and P and Fe K-edge XANES spectroscopy. A partial mineralization of organic matter was shown by comparing organic carbon contents of SS and sludge materials. Chemical fractionations combined with P and Fe K-edge XANES spectroscopy showed that P was predominantly bound to iron within both samples in the form of ferric phosphate, rather than adsorbed onto ferric oxyhydroxide. Calcium-bound P was more significantly observed in sludge than in SS, suggesting that aging induced the recombination of part of the organic and iron-bound P species into calcium-bound forms, as a possible consequence of the partial mineralization of organic matter.
authors.affiliation: †INSA Lyon, University of Lyon, LGCIE-DEEP, 20 av. A. Einstein, 69621 Villeurbanne cedex, France.|‡SCIRPE, 5 Allée Alban Vistel, 69110 Sainte-Foy-Lès-Lyon, France.
authors.forename: Boram
authors.initials: B
authors.lastname: Kim
authors.affiliation: †INSA Lyon, University of Lyon, LGCIE-DEEP, 20 av. A. Einstein, 69621 Villeurbanne cedex, France.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Gautier
authors.affiliation: §ESRF, European Synchrotron Radiation Facility, 38000 Grenoble, France.
authors.forename: Camille
authors.initials: C
authors.lastname: Rivard
authors.affiliation: ∥Université de Lyon, CNRS, Institut des Sciences Analytiques, 5 rue de la Doua, 69100 Villeurbanne, France.
authors.forename: Corinne
authors.initials: C
authors.lastname: Sanglar
authors.affiliation: ‡SCIRPE, 5 Allée Alban Vistel, 69110 Sainte-Foy-Lès-Lyon, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Michel
authors.affiliation: †INSA Lyon, University of Lyon, LGCIE-DEEP, 20 av. A. Einstein, 69621 Villeurbanne cedex, France.
authors.forename: Rémy
authors.initials: R
authors.lastname: Gourdon
mesh_terms: D000327:Adsorption; D002118:Calcium / Q000737:chemistry; D005591:Chemical Fractionation; D004867:Equipment Design; D005374:Filtration / Q000295:instrumentation; D007501:Iron / Q000737:chemistry; D010710:Phosphates / Q000737:chemistry; D010758:Phosphorus / Q000032:analysis* / Q000737:chemistry*; D012722:Sewage / Q000737:chemistry; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater; D053833:Wetlands; D056928:X-Ray Absorption Spectroscopy
chemical_list: D002118:Calcium; D007501:Iron; D010710:Phosphates; D010758:Phosphorus; D012722:Sewage; D062065:Wastewater