PURE WATER PRODUCTION AND DEVICE THEREFOR

PROBLEM TO BE SOLVED: To provide a pure water production device for efficiently removing a carbonic acid component and greatly reducing a discharge quantity of regeneration waste water, though a 2B3T type ion exchange device is eliminated from an equipment. SOLUTION: In the pure water production device for separating and removing ions and organic matters contained in city water, or the like, a pH adjusting tank 5 for adjusting pH of water to an acidic region is provided in a raw water inflow line, and the following devices are successively installed: a gaseous nitrogen bubbling tower 1 for bringing water into contact with gaseous nitrogen to aerate in or a vacuum de-aeration tower, and an activated carbon tower 2 in the front stage of the de-aeration tower or in its back stage, and furthermore, a reverse osmosis device 3 and an ion exchange device 4. Pure water is produced by successively passing water through the above devices.