Biosorption of Pb(II) Ions from Aqueous Solutions by Waste Biomass from Biotrickling Filters: Kinetics, Isotherms, and Thermodynamics

Abstract

A dried biomass wasted from biotrickling filters has been prepared for removing lead [Pb(II)] ions from aqueous solutions. The kinetics, isotherms, and thermodynamics of Pb(II) ion biosorption by the dried biomass were investigated. The results showed that the maximum Pb(II) ion biosorption capacity of a dried biomass was 160.0 mg/g at 25°C according to an evaluation using the Langmuir equation, which was fitted well to the adsorption data. The results of the kinetic studies revealed that the adsorption process followed the pseudo second-order model. The calculated thermodynamic parameters of ΔS°, ΔH°, and ΔG° suggested that the adsorption of Pb(II) ion was endothermic and spontaneous. Fourier transform infrared spectroscopy (FT-IR) analysis illustrated that the amide group and the hydroxide group affected Pb(II) ion removal significantly. This study demonstrated that a dried biomass wasted from biotrickling filters for the removal of n-hexane could be successfully used as adsorbent for the treatment of Pb(II) ion from aqueous solutions and had a higher adsorption capacity.