Removal of chromium (VI) and cadmium (II) from aqueous solution by a bacterial biofilm supported on granular activated carbon

Abstract

A biofilm of Arthrobacter viscosus, supported on granular activated carbon, removed between 100% and 50% of Cr(VI) and between 100% and 20% of Cd(II) from solutions with initial concentrations between 4–11 mgmetal Lˉ¹ and a flow residence time of 1.2 min. For experiments of lower initial concentrations, a steady-state removal of 50% was reached after 71 bed volumes of Cr solution passed through the biosorbent bed and a steady-state removal of 30% was reached after 47 bed volumes of Cd solution passed through a similar bed. Final uptakes of 8.5 mgCr gˉ¹ carbon and 4.2 mgCd gˉ¹ carbon were determined for initial concentrations of 10 mgCr Lˉ¹ and 11 mgCd Lˉ¹, respectively. The influence on the overall process of two different surface treatments of the support was evaluated and compared with the behavior of a support not treated.