Destruction of analgesic and anti-inflammatory pharmaceuticals in water by catalytic and advanced oxidation processes

Abstract

The present study aims to emphasize the occurrence of pharmaceutical residues in water and their treatability in homogeneous and heterogeneous solutions by advanced oxidation processes utilizing ultrasound and a variety of solid catalysts. Hence, an important part of the study is the synthesis of metallic nanoparticles/nanocomposites and the assessment of their catalytic activity in the destruction of pharmaceuticals in water. One of the main highlights of the study is the higher efficiency of heterogeneous processes that were assisted by ultrasound than homogeneous systems due to the properties of ultrasound accelerating the transfer of organic solutes to the solid surfaces, where they adsorbed and reacted with many different reactive species. A second highlight of the research is the utility of ultrasound in modification of conventional catalysts such as titanium dioxide and alumina to enable the synthesis of platinum, gold and palladium-supported nanocomposites. The method was demonstrated to enhance the catalytic activity of the catalysts via the electron-trapping ability of the co-catalyst, the massive surface area, increased number of adsorption sites and e- transfer from co-catalyst for enhanced rate of OH production. Finally, hybrid processes (e.g. sono-ozonation, sono-photolysis, sono-photo-ozonation) was more efficient than singles leading to the generation of excess radical species.