Screening anodic inoculums for microbial fuel cells by quantifying bioelectrogenic activity using tungsten trioxide quantum rods

The aim of this research was to develop a procedure for rapid detection of electrogenic activity of the inoculums using electrochromic tungsten trioxide (WO3) quantum rods, which display blue colouration under an electric field. Optimum dosage of WO3 and sludge concentration to be used for absorbance measurement were determined to estimate electrogenic activity based on blue colouration. Performance of seven MFCs was evaluated using different volumetric ratios of mixed anaerobic sewage sludge and Shewanella putrefaciens as inoculums. Absorbance of inoculums used in MFCs was measured after addition of optimum dosage of WO3 and a correlation is established between this absorbance and respective current densities/CE, obtained in MFCs during steady state operation. This correlation of current densities/CE with absorbance of inoculum can be used to select proper inoculum having highest electrogenic activity, and to predict possible current generation of MFCs, even before start- up, based on the electrogenic activity of inoculum used.