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1. (WO2014209669) WATER DESALINATION/PURIFICATION AND BIO-AGENT PRECONCENTRATION

Pub. No.:    WO/2014/209669    International Application No.:    PCT/US2014/042655
Publication Date: Thu Jan 01 00:59:59 CET 2015 International Filing Date: Wed Jun 18 01:59:59 CEST 2014
IPC: B01D 61/44
B01D 61/46
B01D 61/54
C02F 1/42
C02F 1/46
C02F 1/469
Applicants: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
Inventors: KWAK, Rhokyun
HAN, Jongyoon
Title: WATER DESALINATION/PURIFICATION AND BIO-AGENT PRECONCENTRATION
Abstract:
Between two juxtaposed similar ion exchange membranes (AEMs or CEMs), an ion depletion zone (dde) and ion enrichment zone (den) are generated under an electric field. As cations are selectively transferred through the CEMs, for example, anions are relocated in order to achieve electro-neutrality, resulting in the concentration drop (increase) in ion depletion (enrichment) zone. The concentration drop (i.e. salt removal) is low and spatially gradual at relatively low voltage or current (i.e. Ohmic regime). However, at higher voltage or current (i.e. overlimiting regime), strong electroconvective vortex accelerates cation transport through CEMs, allowing us to "relocate" most salt ions. The flat depletion zone occurs with significantly low ion concentration, and corresponding strong electric field in the zone, and any charged agents cannot penetrate this flat zone. As a result, we can separate and collect the desalted/purified flow from brine flow by bifurcating the channel at the end of the CEMs.