espanolEste trabajo reporta la modificacion de la cascara de la yuca con acido fosforico para la remocion de azul de metileno de soluciones acuosas. Se utilizo una metodologia experimental con diseno compuesto central 3^2+estrella, variando la temperatura de modificacion de la cascara de yuca (113 °C a 127 °C), la relacion biomasa- acido fosforico (1:0.5 a 1:1.5) y la concentracion inicial del colorante (100 a 800 mg/L), utilizando como variables de respuesta el porcentaje de remocion y la capacidad de adsorcion. Se encontro que para el porcentaje de remocion del colorante, la variable mas importante es la temperatura y que la capacidad de adsorcion se favorece a concentraciones altas de colorante. La cascara de yuca modificada a la temperatura mas alta (127 °C) y relacion masica de biomasa- acido 1:1 presento mayores valores tanto para el porcentaje de remocion como para la capacidad de adsorcion, los cuales fueron de 99.984% y 79.975 mg/g respectivamente. La cinetica de adsorcion se ajusto al modelo de pseudo segundo orden lo cual sugiere que el proceso se realiza por quimisorcion, ademas, ajusto con las isotermas de Freundlich, lo que sugiere que la adsorcion se realiza en multiples capas. EnglishThis work reports the modification of cassava peel using phosphoric acid for the removal of methylene blue from aqueous solutions. A central composite design 3^2+star was employed using as manipulated variables the temperature of modification (113° C to 127° C), the biomass- phosphoric acid ratio (1:0.5 to 1:1,5) and the initial concentration of dye (100 to 800 mg/L); the response variables of the experiment were the percentage of removal and the adsorption capacity. It was found that for the percentage of removal of dye, the most important variable is the temperature, and that the adsorption capacity is favored at high concentrations of dye. The cassava peel modified at the highest temperature (127° C) and biomass:acid mass ratio 1:1 showed higher values for both the removal percentage and the adsorption capacity, which were 99.984% and 79.975 mg/g, respectively. The adsorption kinetics was best adjusted to a pseudo second order kinetic model, which indicates that the process is carried out by chemisorption, also, the process was adjusted to Freundlich isotherms, indicating that the adsorption is carried out in multiple layers.