REMOVAL DEVICE OF FINE PARTICLES IN WATER AND ULTRAPURE WATER PRODUCTION/SUPPLY SYSTEM

摘要

In a subsystem and water supply path before a use point in an ultrapure water production/supply process, fine particles having a particle diameter of at most 50 nm-in particular, extremely fine particles having a particle diameter of at most 10 nm-are highly removed from the water. A removal device of fine particles in water according to the present invention comprises a membrane filtration means comprising a microfiltration membrane or an ultrafiltration membrane having a weak cationic functional group. As the microfiltration membrane or the ultrafiltration membrane having a weak cationic functional group, it is preferred to have a polyketone film with the weak cationic functional group. Negatively-charged particles in water are adsorbed by the weak cationic functional group and can thus be removed.