An expired ceftazidime antibiotic as an inhibitor for disintegration of copper metal in pickling HCl media
Medhat M. Kamel, Q. Mohsen, Zeinab M. Anwar, Mehmet A. Shérif
Abstract
The disintegration of Cu metal in 1 mol/L HCl and the mitigating effect of the expired Ceftazidime antibiotic were studied. The inhibition efficacy of Ceftazidime depends on its concentration in the medium. The mitigation efficacy increases from 77.7 to 94.2%, as the Ceftazidime concentration increases from 50 to 300 ppm in the corrosive medium. The polarization results confirmed that the antibiotic acts as a mixed-type inhibitor. The adsorption of the antibiotic on the Cu surface belongs to Timken's model. The adsorption constant, Kads, and the standard free energy change ΔGo were estimated. The adsorption of Ceftazidime drug follows a physical-type. Scanning microscopy (SEM) and energy dispersing X-ray (EDX) techniques demonstrated that the expired antibiotic molecules are firmly adsorbed at the copper surface. Electrochemical modulation (EFM), and polarization tests are in good agreement with the weight lack method.