Patent ID: 8512570

Claim:
A wastewater treatment method, comprising: mixing primary aggregates and a dispersion medium to make a suspension, the primary aggregates comprising a magnetic substance, a binder resin connecting the magnetic substance, and pores among the magnetic substance, the pores having openings on a surface of the primary aggregate; passing the suspension through a filter to allow the primary aggregates to remain on the filter and to form a secondary aggregate comprising the primary aggregates and gaps among the primary aggregates; passing wastewater through the secondary aggregate to remove suspended solids and emulsified oil in the wastewater by adsorbing the suspended solids on surfaces of the primary aggregates and by adsorbing the emulsified oil into the pores; dispersing the secondary aggregate in a dispersion medium to decompose the secondary aggregate into the primary aggregates and to wash the primary aggregates; and collecting the primary aggregates with magnetic separation, wherein an average diameter of the primary aggregates is not less than 10 micrometer and not more than 1 mm, an average diameter of the pores is not less than 0.01 micrometer and not more than 1 micrometer, and an average diameter of the gaps is not less than 0.05 micrometer and not more than 10 micrometer, and wherein the binder resin contains at least one resin selected from a group consisting of a styrene resin, a hydrogenated styrene resin, a butadiene resin, an isoprene resin, an acrylonitrile resin, a cycloolefin resin, an alkylacrylate resin, a phenolic resin, and an alkylmethaacrylate resin.