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 conditions. 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.