ULTRAPURE WATER PRODUCTION METHOD AND SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide an ultrapure water production method and system that can obtain ultrapure water with very low TOC concentration by improving the removal ratio of urea in a reverse osmosis membrane device.SOLUTION: An ultrapure water production method includes: a pressurizing step of pressurizing water to be treated having a urea concentration of 10-100 μg/L to 2.0-4.0 MPa; and a first reverse osmosis membrane treatment step of treating the pressurized water to be treated with a reverse osmosis membrane. An ultrapure water production system includes: a pump that pressurizes water to be treated having a urea concentration of 10-100 μg/L to 2.0-4.0 MPa; and a first reverse osmosis membrane device that treats the pressurized water to be treated with a reverse osmosis membrane.