Of the several electrochemical methods
for pollutant degradation,
the mediated electrooxidation (MEO) process is widely used. However,
the MEO process utilizes only one (anodic) compartment toward pollutant
degradation. To effectively utilize the full electrochemical cell,
an improved electrolytic cell producing both oxidant and reductant
mediators at their respective half-cells, which can be employed for
treating two pollutants simultaneously, was investigated. The cathodic
half-cell was studied first toward maximum [Co
I
(CN)
5
]
4–
(Co
+
) generation (21%) from
a [Co
II
(CN)
6
]
3–
precursor
by optimizing several experimental factors such as the electrolyte,
cathode material, and orientation of the Nafion324 membrane. The anodic
half-cell was optimized similarly for higher Co
3
(SO
4
)
2
(Co
3+
) yields (41%) from a Co
II
SO
4
precursor. The practical utility of the newly
developed full cell setup, combining the optimized cathodic half-cell
and optimized anodic half-cell, was demonstrated by electroscrubbing
experiments with simultaneous dichloromethane removal by Co
+
via the mediated electroreduction process and phenol removal by
Co
3+
via the MEO process, showing not only utilization
of the full electrochemical cell, but also degradation of two different
pollutants by the same applied current that was used in the conventional
cell to remove only one pollutant.