A new immobilization matrice for biological oxidation of ferrous iron in packed bed bioreactor

Abstract

Biooxidation of ferrous iron (Fe2+) by immobilized Thiobacillus ferrooxidans cells was investigated in continuous operation in a laboratory scale packed-bed bioreactor. Thiobacillus ferrooxidans was immobilized in modified polymeric material (sulfonated DVB co polymer with activated carbon coating). In the immobilized bioreactor system, modified polymeric material was tested with respect to the cell's immobilizing performance which determines the oxidation efficiency of ferrous iron and obtained the kinetic data necessary for industrial scale-up of the process. Biooxidation of ferrous iron was investigated as a function Fe2+ concentration (2.0-8.0 g 1 -1), water flowrate (139.8-900.6 ml h-1) and pH (1.8). In continuous operation in a packed-bed bioreactor, the cells-immobilized were stable and showed high constant ferrous iron-oxidizing activity. In this study, the fastest kinetic performance achieved was about 7.58 gFe+2l -1 h-1 at a true dilution rate of 4.94 h-1 corresponding to a hydraulic retention time of 12.16 min. in the bioreactor. © 2008 Elsevier B.V., All rights reserved.