Phenol removal from aqueous solution using advanced oxidation process enabled by a hybrid system: UV/H2O2/O3/TiO2

The need for healthy and pollution-free water is vital given the world's industrialization and population explosion. The removal of chemical pollutants, especially phenol and phenolic compounds, from urban and industrial wastewaters is of particular importance due to their high water solubility and toxicity. Previous physicochemical techniques for phenol removal are no longer cost-effective. Advanced oxidation processes (AOPs) using various oxidizing agents have been recently recognized as an effective method for removing organic compounds through mineralization. The present work evaluated the phenol (100 ppm) removal from aqueous solutions through photooxidation systems of UV exposure, UV/TiO2, O-3, O-3/TiO2, H2O2, H2O2/UV, H2O2/TiO2, H2O2/TiO2/O-3 and H2O2/TiO2/O-3/UV. The results showed a decrease in the phenol concentration by almost half using UV, UV/TiO2, O-3, O-3/TiO2, H2O2, H2O2/UV and H2O2/TiO2 within 50 min. The phenol concentration reached 50 and 71 ppm using H2O2/TiO2/O-3 system within 50 and 70 min, respectively. The UV/H2O2/O-3/TiO2 system reduced the phenol concentration to zero after 40 min. The findings revealed that the AOP enabled by the UV/H2O2/O-3/TiO2 combined system caused the complete removal of phenol, highlighting the capacity of the proposed system to remove toxic aromatic compounds such as phenol released during the wastewater treatment process.