Biosorption of acid dye on Pueraria lobata ohwi. Equilibrium and kinetic modelling

The applicability of the biomaterial kudzu (Pueraria lobata ohwi) for the removal of the acid dye Erionil Marine Blau (EMB) from aqueous medium was investigated. The equilibrium results were described by the Langmuir and Freundlich models and the isotherms parameters were calculated. The experimental data were correlated better by the Freundlich model (R-2 = 0.9029). The effect of the system variables, initial sorbate concentration, mass of biosorbent, agitation rate and particle size, were examined. It was established that the biosorption of EMB on kudzu followed pseudo second order kinetics. The intraparticle diffusion model was also applied to explain the mechanism of dye molecules diffusion through the non-living biomass. The comparative estimation of the results proved the feasibility of using kudzu as an effective biosorbent for the removal of the acid dye EMB from aqueous phase. The highest obtained percent uptake of dye was 93%.