Pretreatment device and the pretreatment method of the water treatment system

A A pre-processing device and the pretreatment method used in a water treatment system or the like using a reverse osmosis membrane, does not require a large installation area, sufficient turbidity by pretreatment without requiring the addition of flocculant You can achieve the quality removal and processing flow rate per unit membrane area (flux) to provide a pretreatment apparatus and pre-processing method can provide a high water treatment system. A 1μm or more, and having a second membrane filtration unit using the first membrane filtration unit and the microfiltration or ultrafiltration membrane with a filtration membrane having an average pore size of less than 10μm pretreatment system for water treatment systems, and pre-processing method can be performed by the pretreatment device. .FIELD 1