An improvement of the sludge electrodewatering process is proposed: the anode flushing by filtrate recirculation. According to this technique, the mixture of filtrates obtained at cathode and anode sides, is used for continuous flushing of anode chamber of the filter press during electrodewatering. The anode flushing is aimed to eliminate essential problems of electrodewatering: ohmic heating, rise of electric energy consumption, electrodes corrosion, and filtrate contamination. This is

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... by better control of the filtrate pH, the filter cake temperature and the dryness at anode side, where the physicochemical conditions are most aggressive. The efficiency of the proposed technique is evaluated at lab scale on drilling sludge electrodewatering with and without anode flushing. In experiments without anode flushing, increasing of electric current density caused strong increase of anode temperature, desiccation of the filter cake at anode side, rise of voltage and significant alkaline contamination of filtrate. The application of anode flushing allowed controlling the electric field strength and the temperature. Thus, the dewatering of the sludge has been extended at high electric field without damaging the filter equipment by drastic