Applying potentials to conductive materials impairs High-loading anaerobic digestion performance by affecting direct interspecies electron transfer

摘要

In order to illustrate the impact that application of positive or negative potential to conducive materials can have on direct interspecies electron transfer (DIET) and reactor performance under high organic loading rates, three continuous laboratory-scale reactors with carbon-cloth electrodes poised at + 0.7 V, - 0.7 V (vs. Ag/AgCl) and no-potential were fed high concentrations of ethanol wastewater. While exoelectrogens and methanogens that are capable of DIET were significantly enriched in poised reactors, they performed worse than the noncurrent control. Volatile fatty acids (VFAs) accumulated more rapidly in the positively then negatively poised reactor, but neither could withstand high-loading rates. These results demonstrate that applying potential to conducive materials had a negative effect on anaerobic digestion under high-loading conditions.