Comparative study on UV-AOPs for efficient continuous flow removal of 4-tert-butylphenol

In the present study, UV-light-driven advanced oxidation processes (AOPs) have been employed for the degradation of 4-tert-Butylphenol (4-t-BP) in water under continuous flow condi-tions. The effects of varying space time (10, 20, 40, 60 and 120 min) and oxidant dosage (88.3 mg/L, 176.6 mg/L and 264 mg/L) were examined. 4-t-BP degradation efficiency in the UV-induced AOPs followed the order of UV/H₂O₂ (264.9 mg/L) ≈ UV/Fe²⁺/H₂O₂ > UV/Fe³⁺/H₂O₂ > UV/H₂O₂ (176.6 mg/L) > UV/H₂O₂ (88.3 mg/L) > UV/Fe-TiO₂ > UV/TiO₂ > UV, while UV/Fe³⁺/H₂O₂ was the most efficient process in terms of Total Organic Carbon (TOC) removal (at the space time of 60 min) among those tested. The combination of UV with 88.3 mg/L H₂O₂ enhanced pollutant removal from 51.29% to 93.34% after 10 min of irradiation. The presence of H₂O₂ contributed to the highest 4-t-BP and TOC removal values. Interestingly, the increase in space time from 20 to 60 min resulted in surpassing of the activity of the Fe-TiO₂ over commercial TiO₂, although it had an almost negligible positive impact on the performance of the UV/H₂O₂ system as well as H₂O₂ concentration. The results obtained showed that more than 80% of 4-t-BP could be successfully degraded by both heterogeneous and homogeneous AOPs after 60 min.