Basic blue 41 dye removal from aqueous solution using lignocellulosic material: kinetics, equilibrium and statistical design optimization

The purpose of this paper is to investigate the adsorption capacity of alfa stems (Stipa tenacissima) to remove the basic blue 41 from aqueous solutions using experimental design technique. The batch kinetic study was essentially based on the variation of initial dye concentration, contact time, adsorbent dose, solution pH and ionic strength. The adsorption equilibrium and kinetic data were fitted with the Temkin isotherm and pseudo-second-order kinetic model. In addition, the exothermic, feasible and non-spontaneous nature of the reaction was confirmed by the thermodynamic study. The use of the factorial experimental design technique allowed the optimization of operational parameters on adsorption process. However, the novelty of this research is the exclusivity of use the downward step-wise regression technique to choose the best-fit model. The maximum adsorption capacity on alfa (300 +/- 12 mg/g) was achieved at 100 mg/L of dye concentration, 0.25 g/L of adsorbent dose, pH 10, with 200 rpm of stirring velocity.

Automated summary

The purpose of this paper is to investigate the adsorption capacity of alfa stems to remove basic blue 41 from aqueous solutions using experimental design technique. The study focused on the variation of initial dye concentration, contact time, adsorbent dose, solution pH and ionic strength. The adsorption equilibrium and kinetic data were analyzed using the Temkin isotherm and pseudo-second-order kinetic model. The thermodynamic study confirmed the exothermic, feasible and non-spontaneous nature of the reaction. The factorial experimental design technique was used to optimize operational parameters on the adsorption process. The novelty of this research lies in the exclusive use of the downward step-wise regression technique to choose the best-fit model. The maximum adsorption capacity on alfa was achieved at specific conditions.