Patent ID: 8480906
Filing Date: 2013-07-09
Classification: C02F

Abstract:
1. A pure water manufacturing method, comprising: a first ultraviolet (UV) oxidation step of irradiating primary pure water containing an organic material at a concentration of 5 to 50 μg/L with ultraviolet rays to oxidize and decompose the organic material in the primary pure water, thereby obtaining a first UV oxidized water; a first deionization step of contacting the first UV oxidized water with a first ion exchange resin to deionize the first UV oxidized water, thereby producing secondary pure water, and sending a part of the secondary pure water to the first UV oxidation step; a second ultraviolet (UV) oxidation step of irradiating the secondary pure water passed through the first deionization step with ultraviolet rays to oxidize and decompose the organic material in the secondary pure water, thereby obtaining a second UV oxidized water; and a second deionization step of contacting the second UV oxidized water with a second ion exchange resin to deionize the second UV oxidized water, thereby producing tertiary pure water, and sending a part of the tertiary pure water to the second UV oxidation step; wherein the first ultraviolet oxidation step includes measuring a total organic carbon (TOC) concentration of the first UV oxidized water to obtain a first TOC concentration, and applying the ultraviolet rays at a radiation intensity at which the first TOC concentration of the first UV oxidized water treated in the first ultraviolet oxidation step results in 1 to 10 μg/L, and the second ultraviolet oxidation step includes measuring a TOC concentration of the second UV oxidized water to obtain a second TOC concentration, and applying the ultraviolet rays at a radiation intensity at which the second TOC concentration of the second UV oxidized water treated in the second ultraviolet oxidation step results in 0.1 to 5 μg/L.