Electrocoagulation of whey acids: anode and cathode materials, electroactive area and polarization curves

Anode (Al and Fe) and cathode (graphite and Ti/RuO2) materials have been tested for electrocoagulation (EC) and purification of the acid whey. The electroactive areas (EA) of electrodes were calculated by the double layer capacitance method. Experiments were performed by cyclic voltammetry, chronoamperometry and polarization experiments. Among cathodic materials, the Ti/RuO2 electrode showed higher EA (2167 cm2) than graphite (1560 cm2). The Fe anode was found more stable than Al with greater charge transfer carried out in less time. Correlation of these results with those obtained during preliminary tests confirmed high removals (79 %) in 8 h. For the Al electrode, 24 h were required to achieve efficiency of 49 %.