Electroflocculation for the treatment of wastewater from dairy food industry: scale-up of a laboratory reactor to full-scale plant

Abstract

The aim of this work was to evaluate the scale-up of a laboratory reactor to full-scale plant for the electroflocculation of dairy food industry wastewater. The structural, operational and financial feasibilities were evaluated in reactors with either aluminum or iron electrodes. The laboratory reactor contained a beaker of 500.0 mL, two metal electrodes (thickness: 0.10 cm, length: 15.0 cm, width: 7.0 cm, distance between electrodes: 2.0 cm, total area for two electrodes in the laboratory reactor: 210.0 cm2), power source and magnetic stirring. The employed operational parameters included operation time of 1.0 h, applied potential intensity of 5.0 V, and electric currents of 0.94 A for aluminum electrodes and 0.71 A for iron electrodes. The scale-up was evaluated considering 110 m3 generated wastewater per day in a dairy food industry. The total applied electric power, electrode consumption, and final temperature after 1 h operation were 64.89 kWh, 1220 g m−3, and 32.19 °C using aluminum electrodes, whereas these values were 30.01 kWh, 1483 g m−3, and 25.64 °C using iron electrodes. Effective structural and operational costs higher than 65.0% in relation to the total costs of operation of the system were associated with the mass consumption of either aluminum or iron electrodes. In general, the scale-up of the laboratory reactor to full-scale plant was structurally, operationally and economically viable compared to the conventional wastewater treatment systems.