Comparative Study of Kinetics of Catalytic Oxidation Process With Fenton's Reagent of Anionic (2-EHS) and Cationic (CTAB) Surfactants

Abstract

In this chapter, a comparative degradation/mineralization study of two surfactants—the anionic surfactant 2-ethyl-hexyl Sodium Sulfate (2-EHS) and the cationic surfactant Cetyltrimethyl Ammonium Bromide (CTAB)— was performed using a combination of AOPs: Fe(II)/H2O2. From experimental studies, it has been established that the optimal pH for the oxidation of surfactants (CTAB and 2-EHS) is the same, and is 2.5. And the optimal concentrations of Fenton reagent for the model system containing cationic surfactant [CTAB]=20 mg/L are [Fe2+]=1*10-3 M, [H2O2]=1*10-3 M and for the model system that contains anionic surfactant [2-EHS]=20 mg/L are [Fe2+]=8*10-4 M, [H2O2]=1*10-3 M. The degradation kinetics of 2-EHS was much faster compared to that of CTAB. As a result of experimental research, it was found that the degradation and mineralization process of anionic surfactant (2-EHS) is highly efficient, and the degree of oxidation/mineralization is 90% compared to cationic surfactant (CTAB), which has an efficiency equal to 50%.