Abstract: A water treatment system 100 includes: a filtration device 16 that includes an RO membrane element 12 and an NF membrane element 14, and treats raw water containing sodium chloride by the RO membrane element 12 and the NF membrane element 14 to generate concentrated raw water; and an electrolytic device 18 that is disposed downstream of the filtration device 16 and electrolyzes the concentrated raw water to generate water containing sodium hypochlorite.

Abstract: A production method for preparing a porous film of a poly(vinylidene fluoride) based resin which has a microstructure providing a satisfactory mechanical strength and permeation performance and is improved in hydrophilic property, without the precise control of temperature before cooling, as well as a porous film prepared by the above method is provided. The above method for producing a porous film wherein a porous film of a poly(vinylidene fluoride) based resin is prepared by dissolving the poly(vinylidene fluoride) based resin in a poor solvent through heating to form a liquid raw material for a film, and then cooling the liquid raw material to bring about a phase separation is characterized in that an organized clay being organized by a hydrophilic compound is dispersed in said liquid raw material for a film in an amount of 1 to 25 parts by weight relative to 100 parts by weight of the poly(vinylidene fluoride) based resin.