Influence of oxalic acid formed on the degradation of phenol by Fenton reagent

► The yield of oxalic acid is dependent on the amount of ferrous ion dosed. ► Oxalic acid formed significantly suppresses the reduction of ferric ion. ► Stagnation of the mineralization is assumed to be due to two mechanisms. ► Mineralization can be enhanced by the intermittent dosing of ferrous ions.