The potential of waste residue obtained from alum manufacturing process tornremove problematic reactive azo dye (Cibacron brilliant red 3B-A) wasrninvestigated. Batch adsorption experiments were carried out to find out the effectsrnof contact times, adsorbent doses, initial dye concentrations, and final pH on thernadsorption of the dye by both unmodified and neutralized adsorbents. The resultsrnof the experiment showed that from initial dye concentration of 50 mg/L, thernadsorption of dye was rapid in the first 15 and 30 minutes of contact time andrnequilibrium is reached in about 90 and 120 minutes for both unmodified andrnneutralized adsorbents, respectively. About 92% the dye was removed byrnunmodified adsorbent at its equilibrium contact time and optimum dose of 12 g/L,rnhowever, only 68% removal efficiency was obtained for neutralized adsorbent at itsrnequilibrium contact time and optimum dose of 15 g/L. The time required to reachrnequilibrium is independent of initial dye concentrations in the working range of thisrnexperiment. For the neutralized adsorbent, the percentage of dye removal is nearlyrnconstant in the initial pH range of 4-9, and the maximum removal of the dye wasrnobtained at initial pH of 3. In the case of unmodified adsorbent, maximum removalrnof the dye was obtained at initial pH of 2. The equilibrium adsorption isothermsrnhave been examined by applying the Langmuir, Freundlich, Dubinin-rnRasdushkevich (D-R), and Temkin models. The experimental results can be bestrndescribed by the D-R isotherm. Adsorption kinetics of was analyzed using thernpseudo first and second order models and the regression results showed that thernadsorption kinetics were more accurately described by a pseudo second-orderrnmodel, moreover, the intra-particle diffusion was not the only rate limiting factor ofrnadsorption of the dye.rnKey words: Cibacron brilliant red 3B-A, unmodified and neutralized adsorbentsrnadsorption isotherm, adsorption kinetics, and intra-particle diffusion.