| abstract |
An apparatus has a platinum group metal carrying resin column provided in a supply line of ultrapure water, and has a pH adjuster injection device and a redox potential adjuster injection device provided in a later stage thereof. The apparatus has a membrane-type deaeration apparatus and a gas dissolving membrane apparatus sequentially provided in a later stage of the devices, and a discharge line communicates with the gas dissolving membrane apparatus. A pH meter and an ORP meter are each provided at some midpoint in the discharge line, and the pH meter and the ORP meter are connected to a control device. Then, the control device controls the amount of adjusters to be injected from the pH adjuster injection device and the redox potential adjuster injection device, on the basis of the measurement results of the pH meter and the ORP meter. |