Adsorption of Iron(III) and Copper(II) by Bacterial Cellulose from Rhodococcus sp. MI 2

Abstract

Modified cellulose from the pellicle produced by Rhodococcus sp. MI 2 was more efficient at removing Fe(III) and Cu(II) from aqueous solution than similarly modified cellulose from Komagataeibar xylinus TISTR 998. This study first describes the modification of the cellulose to produce mercerized bacterial cellulose (MBC), phosphorylated bacterial cellulose (PBC), acid–base cellulose and diethylenetriamine bacterial cellulose (EABC). Their efficacy as adsorbents to adsorb Fe(III) and Cu(II) was then determined. In aqueous solution at pH 4 at initial Fe(III) concentration of 20 mg/L, PBC reached adsorption equilibrium within 195 min. At pH 5 in an initial Cu(II) concentration of 75 mg/L, EABC reached adsorption equilibrium within 210 min. Molecular structures and chemical bonds were examined by Fourier transform infrared spectroscopy (FT-IR) and physical morphologies by scanning electron microscopy. The adsorption kinetics of MBC, PBC and EABC showed good agreement with the proposed pseudo-second order model and the adsorption isotherm was best described by the Freundlich model. Our study determined optimal conditions, molecular structures, physical morphologies and adsorption kinetics. The cellulose produced by the new strain Rhodococcus sp. MI 2 was highly efficient at adsorbing and removing metal ions from aqueous solution.