Comparative Study of the Kinetics and Equilibrium of Nickel(Ⅱ) Biosorption from Aqueous Solutions by Free and Immobilized Biomass of Aspergillus awamori

摘要

In this research, the kinetics and equilibrium of nickel(Ⅱ) biosorption were studied in aqueous solutions using batch technique. The biosorption was carried on Ca-alginate beads, on nonliving mycelium of Aspergillus awamori immobilized on Ca-alginate, and on free fungal biomass. The biosorbents were characterized by FTIR and SEM analyses. The experimental data were analyzed in terms of pseudo-first-order, pseudo-second-order, and intraparticle diffusion kinetic models. It was observed that the biosorption process of Ni(Ⅱ) ions followed well pseudo-second-order model on all biosorbents. The experimental results showed that biosorption equilibrium on blank Ca-alginate, free biomass, and immobilized fungal biomass fit better to the Langmuir model when compared with the Freundlich model in concentration range studied (25-75mg L~(-1)). The results showed that the maximum monolayer biosorption capacity of the immobilized fungal biosorbent was 8.34 mg g~(-1) when compared with the blank Ca-alginate and free biomass with 4.63 and 7.13 mg g~(-1) respectively.