Comparison of o-toluidine degradation by Fenton, electro-Fenton and photoelectro-Fenton processes

► Box-Behnken design (BBD) finds the optimal conditions of o-toluidine degradation. ► Various Fenton processes for o-toluidine degradation. ► The o-toluidine and COD removal in the electro-Fenton process and the photoelectro-Fenton process were more than 91% and 43%, respectively.