Electrical energy per order (EE/O) values provide a basis for comparing
the cost efficiency of photochemically based processes. It is
defined as the electrical energy in kWh required to reduce the concentration
of a pollutant by one order of magnitude in 1000 L of
water. In this study, colour was targeted as the pollutant and was
to be reduced to 20 Pt-Co to fulfil the requirement for this particular
recycled water.