OXIDAREA FOTOCATALITICĂ A AMOXICILINEI CU OXID DE TITAN (IV) ȘI PEROXID DE HIDROGEN

Larisa MOCANU, Maria GONȚA, Vera MATVEEVICI, Veronica PORUBIN-SCHIBĂTOR Universitatea de Stat din Moldova

Аннотация

PHOTOCATALYTIC DEGRADATION OF AMOXICILLIN FROM AQUEOUS SOLUTION BY TITANIUM DIOXIDE (IV) AND HYDROGEN PEROXIDE 

This paper describes a study of photocatalytic oxidation of AMX by titanium dioxide from synthetic solutions in an open photochemical reactor with titanium oxide (IV) and hydrogen peroxide under UV irradiation (254 nm) in a weakly acidic medium. The photochemical oxidation process was carried out in order to optimize the physicochemical conditions for the degradation and efficient oxidation/mineralization of the antibiotic (AMX). Thus, at pH value 3.8, a 200 mg/L dose of TiO2 photo catalyst, and 34 mg/L oxidant concentration (H2O2) lead to AMX degradation rate of 1-2% and an oxidation/mineralization degree, on average, of 92% at a substrate concentration of 100 mg/L. At concen-trations 200 and 300 mg/L of antibiotic, the degradation rate is 55% after 300 seconds and 65% after 180 seconds, respectively. The oxidation/mineralization degree averages 97-98% and increases insignificantly when increasing the oxidation time from 60 seconds to 1200 seconds. Although the treatment process occurs up to 98%, the concentration of the remaining compounds is high (10-12 mgO/L), which indicates the presence of stable organic compounds that are difficult to oxidize under the above conditions. 

Keywords: amoxicillin, photocatalytic oxidation, titanium dioxide, degradation, oxidation/mineralization, synthetic systems.