METHOD FOR REMOVING IONS IN LIQUID AND APPARATUS THEREFOR

摘要

PROBLEM TO BE SOLVED: To enhance the quality of treated water by precipitating phosphate ions as hardly soluble crystals and to achieve the miniaturization of a reactive crystallization apparatus and the cost reduction of chemicals. SOLUTION: In a method for removing ions in water by the reactive crystallization on the surfaces of solid particles fluidized in a reactive crystallization tank in the ascending flow type reactive crystallization apparatus, a polymeric flocculant is added to a part or whole of the treated water of which the ions are subjected to reactive crystallization by the contact with the solid particles and fine crystals are separated from the liquid to which the polymeric flocculant is added and an acid is added to the liquid containing the separated fin particles to dissolve the fine crystals and the liquid having the fine crystals dissolved therein is returned to the bottom part of the reactive crystallization tank.