This work reports the adsorption potential of sludge from biological treatment in the removal of methylene blue (MB) dye, comparing the removal rates of BM using two techniques, activated carbon and sludge. The results show that the sludge has a high adsorption capacity and achieved a removal rate greater than 85% in aqueous solutions.100% removal rates were obtained after 24 hours of treatment for both methods applied.Finally, using the experimental designs, we developed mathematical models for each response after 1 hour and 24 hours to improve optimization and use for predictions.