The Efficiency of UV/S2O82- and UV/ ZnO Photo-Oxidation Process for the Removal of Acetominophen from Aqueous Solution: A Comparative Study

These days, water has a special importance in human life, and access to safe drinking water is essential to maintaining human health. The presence of residual pharmaceutical compounds as emerging contaminants (ECs) in wastewater deteriorates aquatic life and water quality due to the lack of effective treatment processes to remove them. This paper deals with the degradation and demineralization of acetaminophen (ACT) from its aqueous solution under UV-Vis irradiation using ZnO (UV/ZnO) and K2S2O8 (UV/PS). Detailed batch tests were evaluated to investigate the effect of different variables such as pH, catalyst dose, reaction time, drug concentration and mineralization rate. The results showed the higher performance of the UV/PS process and the UV/ZnO at acidic and natural conditions, respectively. The constant reaction rate for ACT removal in the UV/PS process is almost double that of the UV/ZnO process. The results of the remaining TOC tests show that the processes can convert the ACT in the solution into harmless minerals such as carbon dioxide after degradation. Increasing the dose of catalysts to an optimum amount led to an increase in elimination efficiency. The UV/PS process is able to degrade 20 mg/L of acetaminophen in 50 minutes, while the UV/ZnO process breaks down this amount of acetaminophen in 100 minutes. This work can be developed for the removal of ECs related to the pharmaceutical group from contaminated water.