Photocatalytic degradation of ciprofloxacin antibiotic by TiO2 nanoparticles immobilized on a glass plate

This research investigated the photocatalytic degradation of ciprofloxacin by titanium dioxide nanoparticles immobilized on a glass plate in an aqueous solution. The important point about this process is immobilization on glass plate, which resolves difficulties related to separation of catalysts from the solution in the application of sole nanoparticles as well as reusability of nanoparticles. Application of nanoparticles without immobilization on a support medium causes toxic effects in aqueous solutions, which was fixed through immobilization on a glass plate in this study. In this research, 1 gL�1 of TiO2 was immobilized on a glass plate. XRD and SEM indicated that the TiO2 immobilized on the glass plate was highly pure and uniform in size (39.2�74.9 nm). The maximum ciprofloxacin removal efficiency from the synthetic aqueous solution was obtained at the optimal pH of 5, contact time of 105 min, and ciprofloxacin initial concentration of 3 mgL�1. The extent of ciprofloxacin removed under optimal conditions was obtained as 92.81 and 86.57 from the synthetic and real samples, respectively. Evaluation of linear models of kinetics and adsorption isotherms indicated that the data followed pseudo-first-order kinetics as well as Langmuir�Hinshelwood and Freundlich isotherms. Thermodynamic studies revealed that the adsorption of ciprofloxacin on TiO2 nanoparticles immobilized on glass plate is an endothermic and physical process. Considering the high efficiency of this process under real conditions, it can be used for the removal of resistant pollutants from industrial wastewater. © 2019, © 2019 Taylor & Francis Group, LLC

A study on the photocatalytic degradation of p-Nitroaniline on glass plates by Thermo-Immobilized ZnO nanoparticle

ZnO nanoparticles have been synthesized via a hydrothermal technique has been utilized for synthesizing ZnO nanoparticles, which had been immobilized on glass plates for the purpose of settling the portion of p-nitroaniline (PNA) removal that can be attained by performing a photocatalytic degradation process (UV/ZnO). In order to evaluate the structural properties of nanoparticles, we have exerted the SEM, TEM, PL, DRS, and XRD analyzes. The highest efficiency for elimination of p-nitroaniline (94/4) was achieved via the utilization of a photocatalytic degradation procedure (UV/ZnO) at the optimal pH of 7, 105 min contact time, at concentration of p-nitroaniline 10 mg/L, with an immobilized dose of 1 g/L for ZnO. The total organic carbon (TOC) removal has been ascertained under the optimal conditions (maximum 72.2). Thus, the photocatalytic degradation procedure (UV/ZnO) is apparently a viable proposal for degrading the organic compounds from aqueous solution. © 2019, © 2019 Taylor & Francis Group, LLC

Synthesis, characteristics, and photocatalytic activity of zinc oxide nanoparticles stabilized on the stone surface for degradation of metronidazole from aqueous solution

Background: The presence of antibiotics such as metronidazole in wastewater even at low concentrations requires searching for a suitable process such as advanced oxidation process (AOP) to reduce the level of pollutants to a standard level in water. Methods: In this study, zinc oxide (ZnO) nanoparticles were synthesized by thermal method using zinc sulfate (ZnSO4 ) as a precursor, then, stabilized on stone and was used as a catalyst, in order to degrade metronidazole by photocalytic process. Effective factors on the removal efficiency of metronidazole including the initial metronidazole concentration, contact time, pH, and 0.9 gL-1 ZnO stabilized on the stone surface were investigated. Results: The X-ray diffraction (XRD) studies showed that the synthesized nanomaterials have hexagonal Wurtzite structure. Also, scanning electron microscopy (SEM) analysis revealed that the average crystalline size of the synthesized ZnO particles was in the range of 1.9-3.2 nm. The spectra represented a sharp absorption edge at 390 nm for ZnO nanoparticles corresponding to band gap of 3.168 eV. The BET-BJH specific surface area of the synthesized ZnO nanoparticles was 25.504 m2/g. The EDS spectrum of ZnO nanoparticles showed four peaks, which were identified as Zn and O. The maximum removal efficiency was 98.36 for the synthetic solution under a specific condition (pH = 11, reaction time = 90 minutes, ZnO concentration = 0.9 gL-1, and the initial concentration of metronidazole = 10 mgL-1). The photocatalytic degradation was found to follow pseudo-first-order degradation kinetics. Conclusion: Therefore, the ZnO nanoparticles synthesized by thermal decomposition are suitable and effective photocatalytic materials for degradation of pharmaceutical contaminants. © 2021 The Author(s). Published by Kerman University of Medical Sciences