Figure 6. HPLC chromatograms for oxidation products atrazine with at sampling times with approximately 90% atrazine degradation: (a) electrolysis at 10mA/cm2, (b) ozonation, (c) combined ozonation/electrolysis at 10mA/cm2, and (d) combined ozonation/electrolysis + 10 mg/L of MnO2 all conducted at pH=7 with 5 mM phosphate buffer, 28 mM Na2SO4 + 10mg/L atrazine. Retention times zero to time 1.2 minutes were omitted for sulfate electrolyte to maximize resolution of oxidation products. Summary. Atrazine degradation was optimal at a current density of 10.0mA/cm2 with a pseudo-zero order reaction rate of, with respect to atrazine. At current densities >20.0mA/cm2, the ozonation/electrolysis synergism was less favored due to ozone stripping and current-limited mass transport. The application of MnO2 as a suspended solid and as an anode and cathode, demonstrated limited to no improvement to the adsorption of and, subsequent, oxidation of atrazine by ozone. These findings are supported with featureless voltammograms of MnO2-coated electrodes and chromatographic analysis, as well as normalized degradation of atrazine over time and residual ozone concentration. While studies have suggested higher oxides influence the ozonation pathway of ozonation/electrolysis synergism, this report uncovers
Figure 6. HPLC chromatograms for oxidation products atrazine with at sampling times with approximately 90% atrazine degradation: (a) electrolysis at 10mA/cm2, (b) ozonation, (c) combined ozonation/electrolysis at 10mA/cm2, and (d) combined ozonation/electrolysis + 10 mg/L of MnO2 all conducted at pH=7 with 5 mM phosphate buffer, 28 mM Na2SO4 + 10mg/L atrazine. Retention times zero to time 1.2 minutes were omitted for sulfate electrolyte to maximize resolution of oxidation products. Summary. Atrazine degradation was optimal at a current density of 10.0mA/cm2 with a pseudo-zero order reaction rate of, with respect to atrazine. At current densities >20.0mA/cm2, the ozonation/electrolysis synergism was less favored due to ozone stripping and current-limited mass transport. The application of MnO2 as a suspended solid and as an anode and cathode, demonstrated limited to no improvement to the adsorption of and, subsequent, oxidation of atrazine by ozone. These findings are supported with featureless voltammograms of MnO2-coated electrodes and chromatographic analysis, as well as normalized degradation of atrazine over time and residual ozone concentration. While studies have suggested higher oxides influence the ozonation pathway of ozonation/electrolysis synergism, this report uncovers
RET%202015%20Grp1%20Report%20-%207.27.15%20-%20Final.docx