The　adsorption　and　catalytic　ozonation　of　Acid　Red　3R　by　the　granular　activated　carbon　modified　with　nitric　acid　oxidation　and　Fe　oxides　loaded　were　investigated　in　this　study.　The　variation　of　surface　functional　groups　of　treated　activated　carbon　samples　was　determined.　The　influences　of　pH　and　·OH　scavenger　on　catalytic　ozonation　were　discussed.　The　results　showed　that　the　total　surface　functional　groups　of　activated　carbon,　including　carboxyl　group,　lactone　group　and　phenolic　hydroxyl　group,　increased　significantly　after　nitric　acid　modification,　especially　for　carboxyl　group.　However,　the　amount　of　surface　functional　groups　of　activated　carbon　was　reduced　after　Fe　oxides　loaded.　The　larger　amount　of　surface　functional　groups　could　improve　the　adsorption　capacity　of　activated　carbon　samples.　The　catalytic　ozonation　of　Acid　Red　3R　by　activated　carbon　samples　was　more　efficient　than　ozonation　alone.　An　increase　in　the　surface　functional　groups　of　activated　carbon　could　accelerate　catalytic　ozonation,　but　consumption　of　the　surface　functional　groups　during　catalytic　ozonation　resulted　in　reduced　reaction　rate.　Comparatively,　the　Fe　oxides　loaded　activated　carbon　showed　more　stable　and　effective　catalytic　ozonation　activity.　The　catalytic　ozonation　seemed　more　efficient　under　alkaline　condition　rather　than　acidic　condition,　and　higher　pH　value　was　favorable　for　catalytic　ozonation.　The　performance　of　catalytic　ozonation　by　activated　carbon　samples　decreased　significantly　in　the　presence　of　·OH　scavenger　(Na2CO3),　due　to　·OH　consumption　by　Na2CO3.　©,　2014,　Science　Press.　All　right　reserved.