Ultrapure water production apparatus and ultrapure water production method

An ultrapure water production apparatus that sequentially treats water to be treated to produce ultrapure water, comprising:

• a receiving unit that accepts the water to be treated;
• a first pump connected to an outlet of the receiving unit to feed the water to be treated;
• an ultraviolet irradiation device that is installed at a secondary side of the first pump, and irradiates the water to be treated with ultraviolet light to perform ultraviolet oxidation treatment;
• an oxidizing substance removal device that is installed at a subsequent stage of the ultraviolet irradiation device and removes at least oxidizing substances contained in the water to be treated;
• and
• a second pump installed at a subsequent stage of the oxidizing substance removal device to feed outlet water of the oxidizing substance removal device,
• wherein at least a portion of ultrapure water produced is circulated to the receiving unit,
• wherein the oxidizing substance removal device comprises:
• an anode and a cathode;
• a dissolved oxygen removal chamber which is positioned between the anode and the cathode, and filled with an ion exchanger, and through which the water to be treated passes;
• and
• a power supply unit that applies a DC current between the anode and the cathode, and
• wherein at least a portion of the ion exchanger filled in the dissolved oxygen removal chamber is an ion exchanger on which a metal catalyst is supported.