Influence of Fe²⁺ and Fe³⁺ on the Performance and Microbial Community Composition of a MFC Inoculated with Sulfate-Reducing Sludge and Acetate as Electron Donor

Table 2

Operation conditions for the MFC that served as controls in order to evaluate the cyclic voltammetry (CV) determinations of each MFC.

Parameter	MFC acetate	MFC sulfate	MFC medium	MFC Fe^2+	MFC Fe^3+
Mineral medium	No	No	Yes	No	No
Working volume	130 mL	130 mL	130 mL	130 mL	130 mL
Sulfate (SO4^-2)	No	6000 mg/L	No	No	No
Acetate	4000 mg/L	No	No	No	No
Iron concentration	No	No	No	10 mM	10 mM
pH	4.5	4.5	7	4.5	7
Temperature (°C)	25	25	25	25	25
Time	—	—	—	—	—
Inoculum (sludge)	No	No	No	No	No
Graphite cloth area: 16 cm^2	No biofilm	No biofilm	No biofilm	No biofilm	No biofilm

In the case of “no,” the mineral medium was replaced with distilled water; 10 mM (0.56 g/L).