PĂTRUNDEREA ŞI TRANSFORMĂRILE CHIMICE ALE SUBSTANŢELOR ANTIBACTERIENE ÎN MEDIUL ÎNCONJURĂTOR

Abstract

Summary: Recently, pharmaceuticals and personal care products (PPCPs) with their metabolites have been detected as common contaminants in surface waters throughout the world. The most frequently detected compounds were hormones, antibiotics, analgesics, fragrances, disinfectants, diagnostic agents, sunscreen agents, tranquilizers. The major possible impact of antibiotics and other antibacterial products is development of resistant bacteria and potential to disturb environmental bacterial community and processes. One of the main physico-chemical processes of PPCPs degradation is considered photolysis. This work is dedicated to the photodegradation of the antibiotic oxytetracycline hydrochloride. The study has been performed with and without addition of the copper (II) ions which are main catalysts in natural redox processes. It has been found that the photodegradation rate of oxytetracycline hydrochloride for the model system with addition of Cu2+ is lower than for the system without addition of Cu2+. Moreover, there exists a qualitative difference between transformational products formed with and without addition of Cu2+. It is obvious that the formation of Cu-antibiotic complexes causes these differences in the rates and products. Obtained results emphasize the importance of identifying the transformation products and the degradation rates of PPCPs in the presence of natural transition ions (Cu2+, Fe3+, Mn4+) and other cations (Ca2+, Mg2+), which can form complexes with PPCPs, in order to obtain results closer to the real environmental conditions.