In situ bioreduction of hexavalent chromium-contaminated water using a microbial culture barrier

Abstract

Chromium (Cr) has been extensively used in many industrial applications. Inappropriate disposal of effluent has led to increased Cr concentrations in the environment. As a result, Cr(VI) has been classified under strict control measures by most national and international lists of highly toxic materials. Bioremediation of Cr(VI)-contaminated effluents appears to be a more economical and environment- friendly treatment method. This study investigates Cr(VI) removal in a bench-scale bioreactor using municipal dried sludge as a permeable bioreactive barrier. The 20-cm-thick permeable bioreactive barrier with 30% sludge and 70% sand was able to achieve 95% Cr(VI) removal during 90 operational days, demonstrating the effectiveness of the biological permeable reactive barrier system in treating Cr(VI)-containing process effluent streams.