| 摘要 |
PURPOSE:To produce mineral water having an optimum content of Ca<2+> by introducing the water injected with gaseous CO2 into a Ca carbonate-packed tower, measuring the Ca<2+> in the water, and controlling the amt. of gaseous CO2 to be injected so that the measured value becomes the desired value. CONSTITUTION:Gaseous CO2 is injected into pure water, and the obtained water contg. gaseous CO2 is sent into a Ca dissolving tower 2 having a packed bed consisting essentially of Ca carbonate granules to sufficiently elute Ca<2+>. After the treatment in the tower 2 is finished, the Ca<2+> in the treated water is measured, for example, by an ion electrode method using a Ca<2+> liq. membrane ion electrode, and the amt. of gaseous CO2 to be injected is controlled so that the measured value becomes the desired value. In this case, when Lm<3>/hr or water contg. bkg/m<3> of CO2 is used for 1m<3> of granules having a m<2> surface area per m<3> packed bed and consisting essentially of CaCO3, the value bL/a is controlled to <=20g/m<2>hr. As a result, mineral water having an optimum content of Ca<2+> can be produced. |
