This study evaluates the UV/H 2 O 2 and UV/S 2 O 8 2− (UV/PS) processes as alternative methods for the removal of ibuprofen (IBF) from wastewater destined for treatment and reuse. The second-order rate constants of IBF with HO and SO 4 − were determined as kHO/IBF=5.57×109M-1s-1 and kSO4-/IBF=1.32×109M-1s-1. The IBF removal rate was higher in the UV/PS process than in the UV/H 2 O 2 process for deionized water, while a higher IBF removal rate was seen with the UV/H 2 O 2 process than with the UV/PS process for wastewater effluent. The suppression of IBF removal in wastewater effluent was verified by investigating the effects of background water quality using synthetic solutions (HCO 3 − , Cl − , NO 3 − , SO 4 2− , humic acid, and fulvic acid); HCO 3 − and organic compounds showed stronger inhibitory effects on the UV/PS process than on the UV/H 2 O 2 process. A mineralization test on the effluent organic matter (EfOM) revealed a higher efficiency for the UV/PS process than the UV/H 2 O 2 process. A toxic by-product test showed a notably higher production yield of 4-isobutylacetophenone (4-IBAP) with the UV/PS process ηUV/PSIBF→IBAP=0.23 than with the UV/H 2 O 2 process ηUV/H2O2IBF→IBAP=0.019, even though 4-IBAP was removed by both processes.