Electrodialysis unit for water treatment

Abstract

An electrodialysis unit 8 comprises a cathode 68, an anode 70, a membrane 71 between the cathode 68 and the anode 70, a cathode flow path 72 for water flow along the membrane 71 on the cathode side, an anode flow path 74 for water flow along the membrane 71 on the anode side, and a reaction zone formed between the membrane 71 and the cathode 68 where the cathode 68 faces the anode 70, wherein the cathode flow path 72 is arranged for laminar flow in the reaction zone and wherein the electrodialysis unit 8 comprises flow conditioning elements 64 arranged to promote laminar flow in the incoming water flow to the cathode flow path 72.

Description

technical field

[0001] The present invention relates to the treatment of water by electrodialysis, such as treatment to kill microorganisms, preferably sea water, such as ballast water treatment. Background technique

[0002] Ballast water is water carried by a ship in ballast tanks or sometimes in other suitable spaces such as cargo or oil tanks. It is pumped into the tank at the water "donor" location to compensate for changes in the center of gravity as cargo and / or fuel is unloaded / consumed, and thus maintain stability. Proper ballasting is essential from a structural point of view and also for performance reasons in order to ensure proper propeller and rudder immersion, proper bridge considerations and to maintain desired vessel movement and handling characteristics. Ballast water is transported to a water "holding" location, typically where the vessel is loaded with cargo, potentially outside the biogeographical region of the ballast water source. Ballast water can b...

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