ABSTRACT: The purpose of this manuscript was to remove and decolorize vitamin B12 from an aqueous solution of drug tablets using ZrO2 as an environmentally friendly method via advanced oxidation processes. Some oxidant agents such as Fe2+, H2O2, K2S2O8 and their mixture of were performed, and the best adsorption sequences have occurred with increased adsorption capacity: q(K2S2O8 + H2O2)>q(H2O2) >q (K2S2O8) >q (Fe2+ + H2O2) >q (Fe2+)>q (without) Endothermic and physical adsorption occurred of this vitamin on the ZrO2 surface with and without the addition of K2S2O8 +H2O2. On the other side, the photoreaction for this vitamin with and without the addition of K2S2O8 +H2O2 was found to be quick, endothermic, less random, and spontaneous. At 15 min, 33.223 % and 98. 684% were calculated as the maximum percentage of removal in the dark reaction and the maximum decolorization in the photocatalytic reaction respectively
