Degradation of trimethoprim antibiotic by UVA photoelectro-Fenton process mediated by Fe(III)-carboxylate complexes

• Type: Article in International Scientific Journal
• Date: 2015

Authors

Francisca C. Moreira (Author) FEUP; Rui A. R. Boaventura (Author) FEUP; Enric Brillas (Author) Other; Vítor J. P. Vilar (Author) FEUP

Journal

Title: Applied Catalysis B: Environmental

Vol. 162

Pages: 34-44

ISSN: 0926-3373

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 40 Citations

ISI Web of Science

Scopus - 66 Citations

Scientific classification

FOS: Engineering and technology > Environmental engineering

CORDIS: Technological sciences > Technology > Environmental technology

Associated Projects

LA 20 - PROJECTO ESTRATÉGICO - LA 20 - 2013-2014

Other information

Authenticus ID: P-009-TP7

DOI: 10.1016/j.apcatb.2014.06.008

Abstract (EN): A UVA photo electro-Fenton (PEF) process mediated by Fe(III)-carboxylate complexes was applied to the removal of trimethoprim (TMP) antibiotic from water using a 2.2 L lab-scale flow plant equipped with a double compound parabolic collector (CPC) and an electrochemical cell composed of a boron-doped diamond (BDD) anode and a carbon-PTFE air-diffusion cathode. The presence of Fe(III)-carboxylate complexes enhances the regeneration of Fe3+ to Fe2+, allows to maintain iron in solution at higher pH values and can decrease the formation of Fe(III)-sulfate, Fe(III)-chloride and some Fe(III)-pollutants complexes. First, the efficiency of different carboxylate ligands like oxalate, citrate, tartrate and malate was assessed, followed by the application of various initial Fe(III)-to-carboxylate molar ratios and pH values. The PEF process with Fe(III)-oxalate, Fe(III)-citrate and Fe(III)-tartrate complexes revealed similar ability to degrade the antibiotic solution with the employment of 1:3, 1:1 and 1:1 Fe(III)-to-carboxylate molar ratios, respectively, and using pH of 4.5, Fe3+ concentration of 2.0 mg L-1 (total iron emission limit for the discharge of treated effluents according to the Portuguese legislation), current density of 5 mA cm(-2) and 20 degrees C. The PEF process mediated by Fe(III)-malate complexes was much less effective. 1:6 and 1:9 Fe(III)-to-oxalate molar ratios were required to yield similar TMP removal kinetics at pH 5.0 and 5.5 compared to pH 4.5, respectively. Additionally, the influence of initial TMP content and solution temperature on the PEF process with Fe(III)-carboxylate complexes was assessed and the role of the different reactive oxidizing species was clarified by the addition of scavenging agents. Generated low-molecular-weight carboxylic acids were monitored by ion-exclusion HPLC.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 11