Hybrid system to upgrade conventional Fenton's process by incorporating photo-Fenton as a successive treatment process: Degradation of monuron

The degradation of monuron in different remediation processes including UV, UV/H 2O 2, Fenton's process (FP), and photo-Fenton's process (UV/FP) was investigated, and then a hybrid system was proposed based on the results. The processes of UV and UV/H 2O 2 were found to completely remove the monuron, but a longer irradiation time was required. For the FP, a rapid decay of monuron was observed at the beginning of the process but a complete removal was difficult unless very high doses of reagents were used, and negative effects from overdose could be observed. For the UV/FP, both the rapid decay and complete removal of monuron were observed. However, it may not be as cost-effective as the UV irradiation because higher energy consumption was involved. Thus, a new approach on upgrading conventional FP by incorporating UV/FP as a successive treatment process was proposed in this work. This hybrid system could improve the initial decay rate and performance of FP and reduce the power consumption compared to that in the original UV/FP. A hybrid model equation was developed and found to be very useful for predicting the degradation of monuron in the hybrid system.