Feasibility of combined electrochemical and biological treatment for tylosin removal

Abstract

The purpose of this work was to examine biodegradability improvement of tylosin - containing solutions after an electrochemical pre-treatment, since about 70% of the applied drugs are not metabolized and hence can be found in wastewaters.  Cyclic voltammetry with nickel electrode revealed a significant electrochemical activity of tylosin, on nickel electrode. Electrochemical treatment was, therefore, performed in a home-made flow cell. Optimal conditions led to more than 95% conversion yield of tylosine, in oxidation, using alkaline media as supporting electrolyte. TOC analyses of the electrolyzed solution revealed that the level of mineralization remained low, underlying the interest of a combined electrochemical and biological treatment. The biodegradability, based on the BOD₅ on COD ratio, increased from 0, for untreated tylosin, to 0.43 for electrolyzed tylosin at 0.55 V/ESC.