Performance evaluation of PdO/ CuO TiO2 photocatalytic membrane on ceramic support for removing pharmaceutical compounds from water

Abstract

This study investigated photocatalytic degradation of pharmaceutical compound using CuO or PdO–TiO₂ membrane. The synthesized membranes were characterized by some techniques including X-ray powder diffraction (XRD), dynamic light scattering (DLS), scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FT-IR). The structural properties confirmed that the photocatalytic membranes were successfully prepared on ceramic supports. The PdO-TiO₂ and CuO-TiO₂ membranes were employed as photocatalytic membranes to degrade metronidazole (MNZ) and diphenhydramine (DPH) in aqueous solutions, respectively. Some parameters affecting the photocatalytic reaction such as pH, initial concentration, and light source were also investigated. The maximum degradation for both pharmaceutical compounds was obtained at basic pH (pH = 10), low initial concentration (C₀ = 10 ppm) under UV irradiation. At high transmembrane pressure (ΔP = 3 bar), the flow rate across the membrane increased up 0.0078 and 0.0082 cc/s.cm² for CuO-TiO₂ and PdO-TiO₂ photocatalytic membrane respectively while not affected on degradation efficiency (DE). At the same condition operation (C₀ = 10 ppm, pH = 10, ΔP = 2 bar under UV irradiation), the MNZ and DPH degradation of the PdO-TiO₂ membrane was 94 and 95% respectively that relatively higher than the CuO-TiO₂ membrane. It is probably due to the lower energy band gap of PdO-TiO₂ (2.5 eV) than CuO-TiO₂ (2.7 eV). The membrane stability tests confirmed the high performance of the prepared membranes.