Photocatalytic decomposition of metronidazole by zinc hexaferrite coated with bismuth oxyiodide magnetic nanocomposite: Advanced modelling and optimization with artificial neural network.

The objective of the present study was to employ a green synthesis method to produce a sustainable ZnFe12O19/BiOI nanocomposite and evaluate its efficacy in the photocatalytic degradation of metronidazole (MNZ) from aqueous media. An artificial neural network (ANN) model was developed to predict the performance of the photocatalytic degradation process using experimental data. More importantly, sensitivity analysis was conducted to explore the relationship between MNZ degradation and various experimental parameters. The elimination of MNZ was assessed under different operational parameters, including pH, contaminant concentration, nanocomposite dosage, and retention time. The outcomes exhibited high a desirability performance of the ANN model with a coefficient correlation (R2) of 0.99. Under optimized circumstances, the MNZ elimination efficiency, as well as the reduction in chemical oxygen demand (COD) and total organic carbon (TOC), reached 92.71%, 70.23%, and 55.08%, respectively. The catalyst showed the ability to be regenerated 8 times with only a slight decrease in its photocatalytic activity. Furthermore, the experimental data obtained demonstrated a good agreement with the predictions of the ANN model. As a result, this study fabricated the ZnFe12O19/BiOI nanocomposite, which gave potential implication value in the effective decontamination of pharmaceutical compounds.

Adsorption-photocatalytic processes for removal of pentachlorophenol contaminant using FeNi3/SiO2/ZnO magnetic nanocomposite under simulated solar light irradiation.

The adsorption followed by photocatalytic degradation process was examined for the pentachlorophenol (PCP) removal from aqueous solution. These processes were accomplished by using FeNi3/SiO2/ZnO magnetic nanocomposite as an adsorbent-photocatalytic agent and under the irradiation of solar light. The magnetic nanocomposite used was first synthesized and then was characterized using transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), vibrating-sample magnetometer (VSM), and X-ray diffraction (XRD) spectroscopy. The PCP removal efficiency was tested for various factors, including pH, PCP concentration, and nanocomposite dose at different contact times. The characterization results of TEM, FE-SEM, and VSM analysis showed that the synthesized nanoparticles are amorphous and tend to agglomerate due to their high super-paramagnetic property. In addition, the EDX technique showed that the Zn and O elements had the highest weight percent in the synthesized nanocomposite, respectively. On the other hand, XRD analysis revealed that the crystalline size of the nanoparticles was about 42 nm. The kinetic of PCP degradation followed the pseudo-first-order model with R2 = 0.978. According to the results of the isotherm study, the adsorption of PCP onto the nanoparticles followed the Freundlich model. The results of adsorption-photocatalytic degradation experiments showed that 100% removal of PCP was obtained at optimum conditions of pH = 3, nanocomposite dose = 0.5 g/L, contact time = 180 min, and initial PCP concentration of 10 mg/L. Through the results obtained from this study, the adsorption process followed by solar light photocatalytic degradation process using FeNi3/SiO2/ZnO magnetic nanocomposite is found to be an efficacious treatment method for the removal of PCP contaminant from water and wastewater.