Methylene Blue and Remazol Red Removal by Biosorption on Corn Grain Pericarp

This work investigated the potential of corn grain pericarp as a biosorbent for the removal of Methylene Blue and Remazol Red synthetic dyes. The characteristics of the material and the favorable conditions for the adsorption process were studied, besides its kinetic and equilibrium operation. The best conditions for the adsorption process were determined through a factorial design 24 in which the most favorable factors were: 0.050 g of biosorbent, temperature of 50 degrees C for the adsorption of Methylene Blue and 25 degrees C for the adsorption of Remazol Red, pH 10 for the Methylene Blue solution and pH 3 for the Remazol Red solution, without addition of sodium chloride to the solution. In the biosorption of Methylene Blue, the kinetic mechanism fitted the pseudo-first order model with a determination coefficient (R2) equal to 0.9948, and the equilibrium data fitted the Langmuir (R2 = 0.99931) and Sips isotherms (R2 = 0.99952). In the biosorption of Remazol Red, the kinetic mechanism fitted the pseudo-second order model (R2 = 0.9987) and the equilibrium data fitted the Freundlich isotherm (R2 = 0.97000). The corn kernel pericarp, in addition to being low cost, has shown efficiency in the removal of Methylene Blue and Remazol Red dyes.