PRELIMINARY INVESTIGATION OF MANGANESE-CATALYZED OZONATION FOR THE DESTRUCTION OF ATRAZINE

A preliminary experimental study conducted with a conventional bubble ozonation contactor column has shown that small amounts of Mn(LI) grea tly enhanced the destruction of atrazine by ozone. There is an inverse ly linear relationship between the dosed Mn(II) concentration and the residual ozone concentration at a specific reaction time. The ozone tr ansfer efficiency into water is greater with the increase of Mn(II) do sage. Hydrous manganese dioxide prepared by reacting permanganate with manganese sulfate, also was shown to be effective in catalyzing the d estruction of atrazine by ozone. The efficiency of catalytic activity for the destruction of atrazine caused by preformed hydrous Mn(IV) is slightly lower than the case of Mn(II). A lower residual ozone value u sing manganese dioxide compared to the case of ozone alone suggests th at ozone also may be decomposed by hydrous Mn(IV). However, a commerci al MnO2 did not show any catalytic activity for atrazine destruction. The very much greater degree of atrazine oxidation by manganese-cataly zed ozonation compared to ozone alone is speculated to be the result o f the generation of highly oxidative intermediate species such as hydr oxyl radicals during the reaction between ozone and manganese species.