Treatment of wastewaters from the green table olive packaging industry using electro-coagulation

The application of electro-coagulation technology for the pre-treatment (or partial-depuration) of the wastewaters from the green table olive packaging industry was investigated. Different electrode materials and operational conditions were examined. The highest depuration rate was obtained using aluminum in the anode and iron in the cathode, current density of 25 mA cm−2 and distance between electrodes of 0.6 cm. In this case, after 50 min of treatment, chemical oxygen demand (COD) elimination reached 40% and most of the initially present phenols and color of the solutions were removed; the pH was also neutralized. Per cubic meter of wastewater, the total consumption of electricity was 0.76 kWh and the aluminum loss in sacrificial electrode 2.15 g. The treated liquid consisted almost entirely of a solution of lactic and acetic acids, which could be reused in packing or treated by conventional depuration plants.