Abstract

GIRALDO AGUIRRE, A. L et al. Electrochemical Treatment of Water Polluted with β-Lactam Antibiotics. Ciencia en Desarrollo [online]. 2016, vol.7, n.1, pp.21-29. ISSN 0121-7488.

Abstract Oxacillin (OXA), cloxacillin (CLX) and Dicloxacillin (DCX) are β-lactam antibiotics, used to treat infections caused by gram-positive and gram-negative microorganisms, which can reach aquatic systems due to improper disposal or deficient water system treatments, thus representing a risk to the environment. With this work, the degradation of these β-lactam antibiotics was investigated by anodic oxidation using a DSA anode Ti/IrO₂. An experimental design with variables assessing current density, supporting electrolyte, and the concentration of substance, allowed to evaluate the most favorable conditions for the degradation of the β-lactams tested. The best efficiencies in terms of pollutant and antibiotic activity removals, were obtained at high current level (121 mA) and average concentration of NaCl (0.225 mol L⁻¹) as supporting electrolyte; while the concentration of the antibiotic did not exert a significant effect on the system performance. Under these conditions, the antibiotics OXA, CLX and DCX (203 μmol L⁻¹), independently experienced a complete removal after 5 min of treatment, by a degradation pathway, mediated by the action of reactive chlorine species, electrogenerated on the anode surface. Relevant is, that a complete loss of antimicrobial activity was observed, as soon as the parent compound disappeared, indicating that the degradation products do not have an antibiotic potency. Even some by-products were also eliminated by the electrochemical action. The electrochemical oxidation is a technology that has great projection for the treatment of water containing β-lactam antibiotics, due to its high efficiency for both the removal of antibiotics and their antimicrobial activity in short periods of time.

Keywords : Isoxazolyl Penicillins; Anodic Oxidation; Antimicrobial Activity; Anode Type-DSA.

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