Removal and Recovery of Chromium(III) from Aqueous Chromium(III) Using <i>Arthrobacter nicotianae</i> Cells

Abstract

The removal of Cr(III) from aqueous Cr(III) using Arthrobacter nicotianae cells was examined. Cr(III) removal was strongly affected by the pH of the solution and the amounts of Cr(III) removed increased as the pH (1 - 5) of the solution increased. The removal of Cr(III) using the cells was also strongly affected by the Cr(III) concentration of the solution, and obeyed the Langmuir isotherm. The percentage of Cr increased as the cell quantity increased, whereas the amount of Cr (μmol/g dry wt. cells) decreased. The removal of Cr(III) using the cells was very fast, and reached an equilibrium within 6 h from the supply of Cr(III) in the solution. A small amount of Cr(III) absorbed by immobilized cells was desorbed at 30 o C; however, most was desorbed at reflux temperature using diluted HCl. Cr(III) adsorption-desorption cycles can be repeated 5 times using immobilized cells. These results have practical implications for industrial wastewater management.