Impact of current density on the function and microbial community structure in electro-bioreactors

The assessment of bacterial communities in wastewater electro-bioreactors has garnered attention to improve efficiency of wastewater treatment plant (WWTP) processes. This study evaluated the effects of applying different current densities on the function and microbial community structure of an electro-bioreactor by measuring nutrient removal efficiency and analyzing 16S rRNA gene high-throughput sequencing. The electrobioreactors at current density of 3, 5 and 7 A/m(2) resulted in an enrichment of operational taxonomic units belonging to distinct functional bacterial families such as (Nitrospiraceae: 8.5, 12.5 and 12.6% relative abundance, respectively) and (Rhodocyclaceae: 8.1, 8.8 and 9.7% relative abundance, respectively), leading to efficient N-removal ( > 98%) and P-removal (> 98%) higher than the control bioreactor (9.6 and 5.0%, respectively). Applying different electric currents proved to affect microbial community composition in electrobioreactors. The results reported here could prove to be valuable for process control, optimization and improving WWTPs design and operation.