| 摘要 |
PROBLEM TO BE SOLVED: To provide a flocculant which is obtained by developing an aqueous polymer having a more minute particle diameter than that of the currently-used aqueous polymer with the use of a (meth)acryl-based monomer generally used as a commercial product and by controlling a particle diameter of water-in-oil type emulsion when producing particles of a crosslinked or branched aqueous polymer in order to solve cost increase caused by increase of an addition amount range which can be treated, the cost increase being a problem of a water-swellable microgel and a crosslinked or branched aqueous polymer, and to provide a wastewater treatment method.SOLUTION: A flocculant is water-in-oil type emulsion of a cationic or amphoteric aqueous polymer which is obtained by emulsifying and polymerizing a monomer mixture aqueous solution using a surfactant in such a way that the monomer mixture aqueous solution has a dispersed phase and hydrocarbon nonmiscible with water has a continuous phase, wherein the monomer mixture contains a crosslinkable monomer having a mass of 20 to 300 ppm with respect to a specific monomer or the monomer mixture. A particle diameter of the flocculant measured by a scattering type particle size analyzer by laser diffraction is below 0.5 μm. A compound of two kinds of water-in-oil type emulsions can be similarly used. |
