Bio-Electroreduction of Chromium (VI) using Immobilized Sulfate Reducing Bacteria on Conductive Microbial Cellulose Biocathode

Abstract

The present study evaluated effect of conductive microbial cellulose (MC) biocathode as a carbohyrate biopolymer in hexavalent chromium bio-electroreduction using immobilized sulfate reducing bacteria (SRB). The morphology studies using SEM shows that the biofilm of SRB was formed a good density on the conductive microbial cellulose biocathode. The Brunauer, Emmett and Teller (BET) analysis revealed that the particle-size distribution in the conductive biocathode was 0.9 nm. The kinetic studies shows that the Cr (VI) removal process fallow of pseudo-first-order kinetics with a constant rate was 0.6 h− 1. The energy consumption of the bio-electroreduction system was 2.7×10− 2 kWh/m3. The EDXA spectrum of sediments showed the presence of chromium peak, indicating that Cr (VI) was reduced on the bio-resuction system. The obtained results indicate that proposed bio-electroreduction system using immobilized sulfate reducing bacteria on the conductive microbial cellulose biocathode could be an efficient method for chromium bio-reduction from wastewaters.