Effect of the continuous and pulse in situ iron addition onto the performance of an integrated electrochemical–ozone reactor for wastewater treatment

The effectiveness of electrochemical, ozone and integrated electrochemical–ozone processes on industrial wastewater treatment was evaluated. The effect of continuous and pulsing addition of energy was studied. In the electrochemical treatment under pulsing operation, the chemical oxygen demand COD removal was found to be 28% at 60 min while pulsing ozonation led to obtain 48% COD removal after 36 min. In the integrated electrochemical–ozone process with energy pulses, the COD reduction was observed to be 80% after 44 min of treatment. Initial pH was 7.5 at all experiments. Finally, the sludge produced during integrated electrochemical–ozone process with energy pulses was quantified and the morphology was evaluated by scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDS). The amount of sludge produced and electrodes passivation after the integrated method was found to be lower than with the electrochemical method alone.