Batch and continuous packed column studies of chromium (III) biosorption by olive stone

In this work, the biosorption properties of olive stone for removal of trivalent chromium were investigated in batch and continuous systems. First, batch isotherm studies were carried out on laboratory scale to evaluate the Cr (III) biosorption capacity of olive stone. Equilibrium uptake of Cr (III) ions from aqueous solutions by olive stone was fitted to Langmuir, Freundlich, and Redlich-Peterson isotherms. These studies showed that the adsorption data can be described by these isotherms and the maximum sorption capacity of olive stone for Cr (III) by Langmuir model was 5.19 mg g-1 at 25 degrees C and at pH 4. Then, continuous packed bed column configuration was examined as a function of inlet chromium concentration and bed height. Also, the well-established design model, Bed Depth Service Time (BDST) model was used to analyze the continuous sorption data. Finally, the continuous packed bed column data were compared with those of the batch system. (c) 2010 American Institute of Chemical Engineers Environ Prog, 2010