Removal of penicillin group antibiotics azlocillin, cloxacillin, methicillin from wastewater by DFT method

Abstract

Antibiotics administered to living things are excreted either unchanged or with little transformation in living metabolism. Discarded antibiotic residues should not be treated in conventional wastewater treatment plants and may enter the receiver directly. Low temperatures of antibiotic residues in the recipient environment may cause increased resistance of microorganisms, while high amounts may cause them to remain toxic. For this reason, wastewater containing antibiotic residues must be treated. Possible reactions of the penicillin group antibiotics were investigated using the DFT method, which is a molecular modeling method. The penicillin group antibiotic molecules examined are azlocillin, cloxacillin and methicillin. No previous studies have been conducted on the molecules examined. The optimized geometries were drawn with Gauss View 5.0 and then calculated with the Gaussian 09W program using functional density theory (DFT). The geometric structure (bond angles and bond lengths) and possible degradation products of all three molecules were calculated with the DFT method and the 6-31G(d) basis set. Thus, the possible degradation type of these three antibiotic molecules in water was determined. These results will guide experimental workers. © 2025 Elsevier B.V., All rights reserved.