Electrochemical incineration of the antibiotic ciprofloxacin in sulfate medium and synthetic urine matrix

Author(s)

Antonin, Vanessa S. ^[1] ; Santos, Mauro C. ^[1] ; Garcia-Segura, Sergi ^[2] ; Brillas, Enric ^[2]

Affiliation

^[1] Univ Fed ABC UFABC, Ctr Ciencias Nat & Humanas CCNH, Lab Eletroquim & Mat Nanoestruturados LEMN, BR-09210170 Santo Andre, SP - Brazil

^[2] Univ Barcelona, Fac Quim, Dept Quim Fis, Lab Electroquim Mat & Medi Ambient, E-08028 Barcelona - Spain

• Document type: Journal article
• Source: WATER RESEARCH; v. 83, p. 31-41, OCT 15 2015.
• Web of Science Citations: 77

Abstract

The degradation of 100 mL of 0.245 mM of the antibiotic ciprofloxacin in 0.05 M Na2SO4 at pH 3.0 has been studied by electrochemical oxidation with electrogenerated H2O2 (EO-H2O2), electro-Fenton (EF), UVA photoelectro-Fenton (PEF) and solar PEF (SPEF). Electrolyses were performed with a stirred tank reactor using either a boron-doped diamond (BDD) or Pt anode and an air-diffusion cathode. In EF, PEF and SPEF, ciprofloxacin was rapidly removed due to its oxidation with (OH)-O-center dot formed from Fenton's reaction between added Fe2+ and H2O2 generated at the cathode. The larger electrochemical incineration of the antibiotic was achieved by SPEF with BDD with 95% mineralization thanks to the additional attack by hydroxyl radicals formed from water oxidation at the BUD anode surface and the photolysis of final Fe(III)-oxalate and Fe(III)-oxamate species from sunlight. Up to 10 primary intermediates and 11 hydroxylated derivatives were identified by LC-MS, allowing the proposal of a reaction sequence for ciprofloxacin mineralization. A different behavior was found when the same antibiotic concentration was oxidized in a synthetic urine matrix with high urea content and a mixture of PO43-, SO42- and Cl- ions. Since Fenton's reaction was inhibited in this medium, only EO and EO-H2O2 processes were useful for mineralization, being the organics mainly degraded by HClO formed from Cl- oxidation. The EO process with a BDD/stainless steel cell was found to be the most powerful treatment for the urine solution, yielding 96% ciprofloxacin removal and 98% mineralization after 360 min of electrolysis at optimum values of pH 3.0 and current density of 66.6 mA cm(-2). The evolution of released inorganic ions was followed by ion chromatography. (C) 2015 Elsevier Ltd. All rights reserved. (AU)

• FAPESP's process: 11/21656-6 - Binary nanostructured materials based on metals in electrogeration of hydrogen peroxide for ciprofloxacin degradation
• Grantee: Vanessa da Silva Antonin
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 14/04218-3 - Mineralization of ciprofloxacin in synthetic urine by solar photoelectron-Fenton process using a flow plant with a Pt/air-diffusion and/or BDD/air diffusion cell coupled with a compound parabolic collector
• Grantee: Vanessa da Silva Antonin
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate