Investigation into effects of cathode aeration on output current characteristics in a tubular microbial fuel cell|
Amari, S.; Vahdati, M. & Ebadi, T.
This work is mainly focused on studying the
effects of cathode aeration in a tubular mediator-less
microbial fuel cell. COD removal efficiency and the effect
of closing the circuit are among other parameters investigated.
A new combination of electrodes, i.e., platinumcoated
titanium as the cathode and chrome-/vanadiumcoated
stainless steel as the anode, is used in this work.
Aeration of the cathode chamber is carried out by addition
of oxygen, which plays the role of final electron-acceptor
terminal. When the cathode chamber is aerated, the maximum
achievable voltage and current are 630 mV and
1.06 mA, respectively. When the cathode operates under
anaerobic conditions, COD reduced by only 40 % after
90 h, as opposed to 90 % achieved with cathode aeration,
in which case more than 36 % of COD is removed in the
first 8 h, while the rest of it is eliminated over a much
longer period of time (i.e., 82 h). The best curve fitting for
COD removal follows a logarithmic pattern, indicating
higher removal levels when more substrate is available.
Closing the circuit is followed by a plunge in voltage,
which is attributable to the ohmic resistance.
Artificial wastewater; Cathode aeration; Chemical oxygen demand; Microbial fuel cell