Livestock wastewater containing high concentrations of ammonium and nitrate ions was
pretreated with microbubbles and an Fe/MgO catalyst prior to its application in microbial fuel
cells because high ion concentrations can interfere with current generation. Therefore, tests
were designed to ascertain the effect of pretreatment on current generation. In initial tests, the
optimal amount of catalyst was found to be 300 g/l. When 1,000 ml/min O2 was used as the
oxidant, the removal of ammonium- and nitrate-nitrogen was highest. After the operating
parameters were optimized, the removal of ammonium and nitrate ions was quantified. The
maximum ammonium removal was 32.8%, and nitrate was removed by up to 75.8% at a 500 g/l
catalyst concentration over the course of the 2 h reaction time. The current was about 0.5 mA
when livestock wastewater was used without pretreatment, whereas the current increased to
2.14 ± 0.08 mA when livestock wastewater was pretreated with the method described above.
This finding demonstrates that a 4-fold increase in the current can be achieved when using
pretreated livestock wastewater. The maximum power density and current density
performance were 10.3 W/m3 and 67.5 A/m3, respectively, during the evaluation of the
microbial fuel cells driven by pretreated livestock wastewater.

Keywords: Microbial fuel cell, Livestock wastewater, Electricity generation, Microbubble, Catalyst, Ammonium