To provide a water making method for stably manufacturing fresh water from seawater in a higher recovery ratio, and a water making apparatus using the same.
In the water making method for supplying water permeated through the front stage membrane module unit among membrane module units, which are arranged in a multistage fashion, to the rear stage membrane module unit to obtain transmitted water, at least a part of raw water, which contains 3.0-4.8 wt.% of salt components in total, calcium ions in a concentration of 200-500 mg/l and sulfate ions in a concentration of 1,500-3,500 mg/l, is treated in the front stage membrane module unit and, after the total concentration of salt components in raw water is adjusted to 55-90% and the concentration of calcium ions in raw water is adjusted to 95% or less, the treated raw water is supplied to the rear stage membrane module unit to obtain permeated water.
NAKANISHI TAKAYUKI
KITADE TAMOTSU
Next Patent: WATER MAKING METHOD AND WATER MAKING APPARATUS