A method for removing calcium from water containing a high concentration of calcium
bicarbonate, permitting a reduction of the calcium bicarbonate equivalent to 200-500
ppm calcium to the level in accordance with the water quality standards for industrial
use, not by a method using a large amount of heat and power as heating and deairing,
but by a simple chemical treatment. Calcium hydroxide is added to waste water containing
a high concentration of calcium in a form of calcium bicarbonate for making them
react with each other, and removing calcium by fixing it to calcium bicarbonate.
