Patent ID: 6780328
Filing Date: 2004-08-24
Classification: B01D,B01J,C02F

Abstract:
A method for purifying water, wherein the water contains both (i) ionizable and/or ionized organic carbon compounds and (ii) non-ionized and/or non-ionizable organic carbon compounds, such method comprising the steps of:(a) processing a first stream of the water with a deionization apparatus to remove from the water ionized organic carbon compounds and certain organic compounds that are ionizable in said deionization apparatus, wherein at least some of such ionized and/or the certain ionizable organic carbon compounds are susceptible to conversion to non-ionized and/or non-ionizable organic carbon compounds by an agent intended for converting non-ionized and/or non-ionizable organic compounds into ionized and/or ionizable organic compounds, thereby producing a first product stream containing a smaller concentration of ionized and/or ionizable organic carbon compounds including the certain organic compounds, than the first stream; (b) immediately following step (a), contacting the first product stream with said agent for converting non-ionized and/or non-ionizable organic carbon compounds into ionized and/or ionizable organic carbon compounds at a time and a temperature sufficient to form a second product stream containing a smaller concentration of non-ionized and/or non-ionizable organic carbon compounds than the first stream and a larger concentration of ionized and/or ionizable organic carbon compounds than the first product stream; (c) processing the second product stream with a second deionization apparatus, which differs from said first deionization apparatus, for removing ionized and/or ionizable organic carbon compounds from the water to form a third product stream containing a smaller concentration of ionized and/or ionizable organic carbon compounds and of non-ionized and/or non-ionizable organic carbon compounds than the first stream; and (d) recovering the third product stream from step (c), wherein each of said first deionization apparatus and said second deionization apparatus is selected from the group consisting of electrodeionization apparatus, electrodialysis apparatus, filled cell electrodialysis apparatus and electrodiaresis apparatus.