| 摘要 |
PURPOSE: Provided is a nanofiltration method which elevates the concentration of calcium and improves taste of water by circulating some discharged water from nanofiltration filter through existing purification method mixed with microfiltration, ultrafiltration and the membrane separation of nanofiltration. CONSTITUTION: The nanofiltration method comprises the steps of (i) the separation of microorganisms and solid substance with the membrane of which pore size is 0.1-5 μm, (ii) the separation of all microorganisms except virus with the membrane of which pore size is 0.01-0.5 μm, (iii) the control of hardness with 0-200 mg/l after separating virus with the membrane of which pore size is 0.1-5 nm, (iv) the elevation of hardness at the extent of 10-100 mg/l by circulating some discharged water from nanofiltration filter, (v) the ion exchange of circulated water for removing sulfate.
|
