Degradation of methyl violet by Fenton’s reagent: kinetic modeling and effects of parameters

ABSTRACT The degradation of methyl violet by Fenton treatment was modeled. A mathematical model was tested by fitting experimental data and was compared with first-order and second-order models. The results indicated that this mathematical model could better describe the kinetics of methyl violet degradation by Fenton in the experimental research scope. In addition, the effects of initial molar ratios of the Fenton reagents ([Fe(II)]0:[H2O2]0), pH, and some anions (e.g. Cl−, , and ) on the Fenton degradation of methyl violet were discussed. The results implicated that the greatest decolorization rate of methyl violet could be obtained when the initial molar ratios of [Fe(II)]0 and [H2O2]0 was 1:3 and the optimum pH was 3.0. The degradation of methyl violet was inhibited in the presence of anions, which can be attributed to the fact that they were scavengers of . And the negative impact of these anions on the degradation rate followed the order  > Cl− >  .