Author, as appears in the article.: A. Dafinov; V. Pinos; F. Medina; J. Sueiras
Department: Enginyeria Química
URV's Author/s: DAFINOV, ANTON IVANOV; V. Pinos; MEDINA CABELLO, FRANCISCO; SUEIRAS ROMERO, JESÚS EDUARDO
Keywords: Chromate reduction Catalytic membrane reactor Pd and Pd/CeO2/Fe2O3 active phases
Abstract: A novel method for catalytic reduction of chromium(VI) to chromium(III) in model and real water is proposed in this work. Hydrogen was used as a reducer. Three different catalytic membrane reactors were prepared and employed in the studied reaction. The catalytic membrane reactors were prepared using commercial corundum hollow fiber membranes. The active phases, palladium, cerium oxide, iron oxide or combinations of them, were incorporated by incipient wetness impregnation of the corresponding water-soluble salts followed by calcination and reduction. The catalytic tests were performed in semi-batch mode at ambient conditions. A mass flow controller was used to supply hydrogen to one end of the membrane whilst the other end was kept closed. The reactors were submerged into a vessel containing the chromate solution. The concentration of the chromate was continuously monitored following a standard analytical method. The initial chromate concentration was varied between 0.5 and 18 mg L-1. In order to completely reduce the Cr(VI) to Cr(III), it was necessary to decrease the pH of the solution to 3. In the end of the tests the final solutions were neutralized to pH 8 and filtered. The content of chromium in the final solutions and in the precipitates was determined by inductively coupled plasma (ICP) technique. It was demonstrated that for the studied reaction the presence of palladium is essential. In all experiments, with synthetic and real water adjusted to pH 3, the catalytic membrane reactors containing palladium (0.3-0.9 w/w%) effectively reduced the chromium to levels below 0.03 mg L-1 without losing activity in repetitive runs. The results from ICP analyses demonstrated that the chromium can be completely eliminated from the water after neutralization and filtration.
Research group: Catàlisi heterogènia
Thematic Areas: Enginyeria química Ingeniería química Chemical engineering
licence for use: https://creativecommons.org/licenses/by/3.0/es/
ISSN: 2213-3437
Author identifier: n/a; n/a; 0000-0002-3111-1542*; 0000-0002-4059-0506
Record's date: 2016-04-13
Last page: 1889
Journal volume: 4
Papper version: info:eu-repo/semantics/acceptedVersion
Link to the original source: https://www.sciencedirect.com/science/article/abs/pii/S2213343716300872?via%3Dihub
Licence document URL: https://repositori.urv.cat/ca/proteccio-de-dades/
Article's DOI: 10.1016/j.jece.2016.03.008
Entity: Universitat Rovira i Virgili
Journal publication year: 2016
First page: 1880
Publication Type: Article Artículo Article