WATER TREATMENT METHOD, AND WATER TREATMENT SYSTEM

摘要

Provided are a water treatment system and a water treatment method with which salt-containing water can be recycled with a high water recovery rate. This water treatment system (100) is provided with: second desalination units (210a, 210b) for separating water to be treated including Ca ions, SO4 ions, and carbonate ions, into treated water and concentrated water in which the Ca ions and SO4 ions are concentrated; crystallization units which are provided to downstream sides of the second desalination units (210a, 210b), and which are provided with second crystallization tanks (221a, 221b) for inducing crystallization of gypsum from the concentrated water, and seed-crystal supply units for supplying gypsum seed crystals to the second crystallization tanks (221a, 221b); and separation units which separate gypsum from the concentrated water at downstream sides of the crystallization units.