DRINKING WATER PURIFYING METHOD

摘要

PURPOSE: A drinking water purifying method is provided, in which membrane filtration processes are adopted to remove all of microorganisms including virus together with impurities of organic matter and to adjust the hardness to a suitable state, so that the method can produce safe drinking water suitable for human body. CONSTITUTION: The method comprises the steps of removing solid matter of large particle by sand filtering; adsorbing heavy metal and organic matter by activated carbon filtration; separating microorganism containing a part of solid matter and protoplasm by filtration membrane of 0.1 to 5 μm pore size; separating all microorganisms except virus by ultrafiltration membrane of 0.01 to 0.5 μm pore size; separating virus by nano filtration membrane of 0.1 to 5 nm pore size, followed by adjusting the hardness to 0 to 200 mg/L. One or all of ultraviolet ray sterilization and ozone sterilization is added to the prior steps of the above filtration processes.