Residual biomass of chia seeds (Salvia hispanica) oil extraction as low cost and eco-friendly biosorbent for effective reactive yellow B2R textile dye removal: Characterization, kinetic, thermodynamic and isotherm studies

Abstract

Residual chia-seed-oil-extraction biomass was studied as a biosorbent for removal of Reactive Yellow B2R textile dye from aqueous solutions in batch system to suggest an appropriate and eco-friendly application, other than incineration or landfill. This residue does not require previous treatment, biosorption process responded very well at temperature of 303 K and time up to 60 min, characterizing a highly practical application in textile wastewater treatments. Biosorption process was concluded effective by kinetic, thermodynamic and equilibrium studies. Efficiency was maximum at pH 2 and 150 rpm of agitation speed. Kinetic studies presented equilibrium time of and approximately 92% of dye removal from aqueous solution, and pseudo-second order was the best fit. Toth adsorption isotherm indicated the maximum biosorption capacity of 70.95 mg g1 and the heterogeneity parameter of 1.2785, both suggesting good pollutant removal ability by biosorbent and a slight degree of heterogeneity of biosorbent surface, respectively, indicated also by the evaluation of the SEM images of the unloaded and dye-loaded biosorbent surface. Biosorption process occurs favorably, spontaneously and possibly through physical adsorption, indicating possible dye recovery and reuse of the biosorbent, as concluded by thermodynamic studies.