(Fig. 4b). On 15th day of operation higher current of 6.5 mA was
observed initially that showed a drastic drop for a few seconds
and then stabilized near 2.5 mA after 250 s. The differential behavior
of CA pattern indicated effective performance of SBES from 10th
day to 20th day of operation where e_ generated constantly facilitated
power generation. This behavior of SBES might be due to the
efficient metabolic function of electrochemically active biocatalyst
around electrode (anode) surface. Observed negligible electrochemical
activity shown by the biocatalyst on 30th day of operation
might be due to the less availability of simple substrate.
Charge (Q) represents the number of e_ present at particular
instance on the electrode (anode) surface throughout oxidation.
Charge distribution was observed to vary with time and metabolic
functions of the biocatalyst used. Voltammetric profiles showed
higher charge on the 20th day (125 mC) followed by 10th day
(102 mC), 0th day (79 mC) and 30th day (54 mC) of SBES operation.
The trend indicated higher availability of e_ on the anode surface
resulting in higher power output. Charge separation can also be
represented by capacitance and the complexity of charge transfer
by its resistance. Capacitance is the capability of a cell to hold an
electrical charge and is a measure of the sum of electrical energy
stored at an applied electric potential given by