Light-driven advanced oxidation processes in the disposal of emerging pharmaceutical contaminants in aqueous media: A brief review

People typically discard pharmaceutical products into the trash, or garbage or sewage systems to ultimately ending up in municipal wastewater treatment plants, which traditionally use non-photochemical ozonation to decompose contaminants, but often failing to completely eliminate them. Accordingly, photochemical advanced oxidation processes (AOPs) have been developed to remedy such situations. Unfortunately, these remain at the developmental stages and have yet to be implemented in practical applications. This review describes UV/ozonation, UV/peroxidation, UV/ozonation/peroxidation, photo-Fenton processes, and photo-catalytic oxidation processes (e.g. UV/TiO2) all of which depend on generating highly reactive oxygen species (e.g., center dot OH radicals, hydroperoxy radicals, superoxide anion radicals) to dispose of emerging aquatic contaminants. Albeit non-exhaustive, the review explores the progress made in the last 2-3 years by focusing on light-driven degradation processes to eliminate such pharmaceutical contaminants as non-steroidal anti-inflammatory drugs (NSAIDs), antibiotics and hormones, many of which have been detected in aqueous ecosystems.