| abstract |
An object of the present invention is to efficiently treat wastewater containing solids discharged from a manufacturing process of an aqueous dispersion in an electrophotographic toner manufacturing plant and reduce the amount of coagulant used and the amount of sludge generated. In an agglomeration reaction process of wastewater containing solids discharged from a production process of an aqueous dispersion containing a surfactant, a colorant and silica in a production plant for water-based paints, electrophotographic toners and the like. By making the pH of the waste water in the range of 4 to 6 and the silica surface potential in the range of +20 mV to -20 mV, the treatment can be performed efficiently, and the amount of flocculant used and the amount of sludge generated are reduced. be able to. [Selection] Figure 1 |