In comparison, particulates introduction to the anode together
with the domestic wastewater (Run 7) can stimulate the
syntrophic interactions (fermenters, H2 consumers, and ARB)
[7,13], which can efficiently provide substrate available for ARB
(e.g., acetate and H2). The current density of 0.5 A/m2 at Run 7,
which is 0.2 A/m2 higher than that at Run 3 and 4, supports the
importance of the syntrophy, since the number of non-ARB would
be trivial in the anode for Run 3 and 4 (filtrated wastewater).
Hence, stimulation of the syntrophic interactions seems very
critical for improving current density in MXCs treating domestic
wastewater.