Abstract: An electrodialysis unit 8 comprises a plurality of cathodes 68, a plurality of anodes 70 and a plurality of membranes 71; wherein the cathodes 68 and anodes 70 are arranged alternately in an electrode stack, with membranes 71 in between each cathode 68 and anode 70; and wherein the cathode 68 and the anode 70 are each formed of a single conductive plate such that both surfaces of the cathode plates and anode plates enclosed within the electrode stack are, in use, in conductive contact with the water being treated.

Abstract: An electrodialysis unit comprises a plurality of cathodes, a plurality of anodes and a plurality of membranes; the cathodes and anodes being arranged alternately in an electrode stack, with membranes in between each cathode and anode, anode flow paths formed between the membranes and anodes and cathode flow paths formed between the membranes and cathodes; the electrodialysis unit further comprising: an inlet manifold for distributing water to the anode flow paths or to the cathode flow paths, wherein the inlet manifold comprises a first tube provided with holes along its length, the holes being connected to the flow paths, and a second tube located within and enclosed by the first tube, the second tube having an inlet at one end and being closed at its second end and the second tube being provided with holes along its length that open into the first tube.

Abstract: A liquid or water treatment apparatus comprising one or both of an electrodialysis cell and a cavitation unit. The cavitation unit generates cavitation in the liquid by flow of the liquid into a constriction where cavitation bubbles are formed and then to an outlet where cavitation bubbles implode, and the constriction includes an aperture formed by walls which are long and narrowly spaced in a plane normal to the flow direction. The electrodialysis cell is arranged with an inlet flow path for directing only part of a quantity of water to be treated through the electrodialysis cell, and an outlet flow path for returning a product of the electrodialysis cell to the remainder of the water.

Abstract: A liquid or water treatment apparatus comprising one or both of an electrodialysis cell and a cavitation unit. The cavitation unit generates cavitation in the liquid by flow of the liquid into a constriction where cavitation bubbles are formed and then to an outlet where cavitation bubbles implode, and the constriction includes an aperture formed by walls which are long and narrowly spaced in a plane normal to the flow direction. The electrodialysis cell is arranged with an inlet flow path for directing only part of a quantity of water to be treated through the electrodialysis cell, and an outlet flow path for returning a product of the electrodialysis cell to the remainder of the water.