Please use this identifier to cite or link to this item:
https://hdl.handle.net/10216/106023
Author(s): | Belisa A. Marinho Raquel O. Cristóvão José M. Loureiro Rui A. R. Boaventura Vítor J. P. Vilar |
Title: | Solar photocatalytic reduction of Cr(VI) over Fe(III) in the presence of organic sacrificial agents |
Issue Date: | 2016 |
Abstract: | Toxic hexavalent chromium reduction to less toxic trivalent chromium was evaluated using a solar driven photocatalytic system, Fe(III)/UV, in the presence of organic sacrificial agents. The photocatalytic reduction experiments were conducted in a lab-scale tubular photoreactor with compound parabolic collectors under simulated solar radiation. The effect of parameters such as iron (1-12 mg L-1) and citric acid (0.058-3.840 mM) concentrations, pH value (3.0-8.0), temperature (15-40 degrees C), UVA irradiation source and initial Cr(VI) concentration (1, 10, 20, 40 mg L-1) on the process efficiency was analyzed, and also the addition of other organic ligands like oxalic acid, maleic acid and EDTA. The presence of citric acid proved to enhance the Cr(VI) reduction by Fe(III)/UV due to the formation of Fe(III)-Citrate complexes, providing a quicker pathway for ferric iron regeneration in the presence of UV-vis light. The organic ligands proved to act also as sacrificial agents of reactive oxygen species formed, avoiding the Cr(III) re-oxidation. The catalytic activity of the organic ligands in the Cr(VI) reduction by Fe(III)/UV followed this order: citric acid > oxalic acid > EDTA > maleic acid. The best Cr(VI) reduction (99% in 15 min) was achieved with citric acid in a Cr(VI):Citric acid molar ratio of 1:3 at pH 5 and 25 degrees C. Finally, the photocatalytic reduction of Cr(VI) present in a real effluent was achieved after 30 min, demonstrating the potential of the Fe(III)/UVA-vis/citric acid system for the treatment of Cr(VI) containing wastewaters. |
Subject: | Engenharia química, Engenharia do ambiente Chemical engineering, Environmental engineering |
Scientific areas: | Ciências da engenharia e tecnologias::Engenharia do ambiente Engineering and technology::Environmental engineering |
URI: | https://hdl.handle.net/10216/106023 |
Related Information: | info:eu-repo/grantAgreement/FCT - Fundação para a Ciência e a Tecnologia/Projetos Estratégicos/UID/EQU/50020/2013- POCI-01-0145-FEDER-006984/Laboratório de Processos de Separação e Reação - Laboratório de Catálise e Materiais/LSRE-LCM |
Document Type: | Artigo em Revista Científica Internacional |
Rights: | restrictedAccess |
Appears in Collections: | FEUP - Artigo em Revista Científica Internacional |
Files in This Item:
File | Description | Size | Format | |
---|---|---|---|---|
130549.pdf Restricted Access | 888.26 kB | Adobe PDF | Request a copy from the Author(s) |
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.