| 摘要 |
PURPOSE:To decrease the amt. of regenerating agents for ion exchange resins to be used considerably by flowing the greater part of acidic soft water to an anion exchange resin tower, mixing this with the remaining part of the acidic soft water then treating the water with a reverse osmosis membrane and mixing the treated water with raw water. CONSTITUTION:Raw water 5 contg. >=60mg SiO2/l silica is flowed into a raw water storage tank 6, and non-permitted water 7 of a reverse osmosis device 4 is flowed into a storage tank 6, whereby mixed water 8 is obtained. The water 8 is flowed by a pump 9 into a cation exchange tower 1. Here, resins are imperfectly regenerated and are controlled in such a way that the leak amt. of the univalent cations of the acidic soft water 10 flowed out from the tower 1 attains 50-30mg CaCO3/l. After the water 10 is flowed into a decarbonation tower 2, treated water 11 is flowed in an anion exchange resin tower 3. Part of the water 11 is mixed with the water 13 treated therein to make treated water 14 which is supplied to a reverse osmosis device 4. |
