removal of lead(ii) from aqueous solution with ethylenediamine-modified yeast biomass coated with magnetic chitosan microparticles: kinetic and equilibrium modeling

the adsorption of pb(ii) ions from aqueous solution with ethylenediamine-modified yeast biomass coated with magnetic chitosan microparticles (eymc) was studied in batch adsorption system. the adsorption of pb(ii) ions increased with the rising ph and a higher adsorption capacity was achieved at the ph 4.0–6.0. the experiment data was well matched by langmuir model and freundlich model, while langmuir model showed the best description. the maximum adsorption capacities obtained by langmuir model were 121.26, 127.37 and 134.90 mg g⁻¹ at 20, 30 and 40 °c, respectively. kinetic studies indicated that the pseudo-second-order model was appropriate to describe the adsorption process and film diffusion maybe governed the rate of the adsorption. thermodynamic studies revealed that a spontaneous and endothermic adsorption process. the adsorbents, eymc can be well recovered by 0.1 m edta.