The　presence　of　sulfonamides　(SAs)　in　water　has　received　increasing　attention　due　to　the　risk　to　ecosystems.　The　adsorption　and　photocatalysis　performance　for　sulfamerazine　(SMZ)　of　Bi2O3-TiO(2)supported　on　powdered　activated　carbon　(Bi2O3-TiO2/PAC)　nanoparticles　was　evaluated.　The　amount　of　doped　Bi(2)O(3)not　only　influenced　the　photocatalytic　performance　but　also　impacted　the　adsorption　capacity.　The　adsorption　mass　transfer　mechanism　of　Bi2O3-TiO2/PAC　was　elucidated　and　is　further　discussed　in　combination　with　the　photocatalytic　mechanism.　It　was　indicated　that　Bi2O3-TiO2/PAC(10%-700　degrees　C)　performed　best,　and　the　SMZ　removal　by　the　adsorption-photocatalysis　of　Bi2O3-TiO2/PAC(10%-700　degrees　C)　reached　95.5%.　Adsorption　onto　active　sites　was　a　major　adsorption　step,　and　external　diffusion　was　assisted.　Superoxide　radical　(O-BLACK　CIRCLE(2)-)　and　hole　(h(+))　were　identified　as　the　major　reactive　oxygen　species　(ROS)　for　SMZ　removal.　Benzene　ring　fracture,　SO(2)extrusion　and　nitrogenated　SMZ　were　proposed　as　the　main　pathways　for　photocatalysis.　Meanwhile,　alkaline　conditions　enhanced　photocatalytic　performance,　while　contrary　effects　were　observed　for　adsorption.　The　adsorption-photocatalysis　removal　performance　for　SMZ　in　lake　water　was　better　than　that　for　river　water.　It　can　be　generalized　for　the　potential　application　of　photocatalysis　coupling　with　adsorption　to　remove　refractory　antibiotics　in　water.