Removal of Penicillin G by combination of sonolysis and Photocatalytic (sonophotocatalytic) process from aqueous solution: process optimization using RSM (Response Surface Methodology)

Abstract

IntroductionPenicillin G (PG) is used in a variety of infectious diseases, extensively. Generally, when antibiotics are introduced into the food chain, they pose a threat to the environment and can risk health outcomes. The aim of the present study was the removal of Penicillin G from an aqueous solution through an integrated system of UV/ZnO and UV/WO3 with Ultrasound pretreatment.MethodsIn this descriptive-analytical work dealing with the removal of Penicillin G from an aqueous solution, four significant variables, contact time (60–120 min), Penicillin G concentration (50–150 mg/L), ZnO dose (200–400 mg/L), and WO3 dose (100–200 mg/L) were investigated. Experiments were performed in a Pyrex reactor (batch, 1 Lit) with an artificial UV 100-Watt medium pressure mercury lamp, coupled with ultrasound (100 W, 40 KHz) for PG pre-treatment. Chemical Oxygen Demand (COD) was selected to follow the performance of the photo-catalytic process and sonolysis. The experiments were based on a Central Composite Design (CCD) and analyzed by Response Surface Methodology (RSM). A mathematical model of the process was designed according to the proposed degradation scheme.ResultsThe results showed that the maximum removal of PG occurred in ultrasonic/UV/WO3 in the presence of 50 mg/L WO3 and contact time of 120 minutes. In addition, an increase in the PG concentration caused a decrease in COD removal. As the initial concentration of the catalyst increased, the COD removal also increased. The maximum COD removal (91.3%) achieved by 200 mg/L WO3 and 400 mg/l ZnO, a contact time of 120 minutes, and an antibiotic concentration of 50 mg/L. All of the variables in the process efficiency were found to be significant (p < 0.05). Catalyst dose and contact time were shown to have a positive effect on the response (p < 0.05).ConclusionThe research data supported the conclusion that the combination of advanced oxidation process of sonolysis and photocatalytic (sonophotocatalytic) were applicable and environmentally friendly processes, which preferably can be applied extensively.