Ammonium perfluorooctanate wastewater treatment method

Abstract

The invention provides a method for treating ammonium perfluorooctanoate wastewater. Pump the clear and transparent wastewater containing ammonium perfluorooctanoate into the foam separation tower for foam separation. After defoaming the foam at the top of the wastewater tower, a high-concentration ammonium perfluorooctanoate aqueous solution can be obtained, which can be reused; the aqueous solution of ammonium perfluorooctanoate with a lower concentration is obtained at the bottom of the tower; the foam is separated The ammonium perfluorooctanoate aqueous solution discharged from the bottom of the tower is filtered by the first-stage nanofiltration membrane, the nanofiltration retentate is concentrated, and returned to the foam separation tower for foam separation; the permeate of the first-stage nanofiltration membrane enters the second-stage nanofiltration membrane; the permeate of the second-stage nanofiltration membrane has reached the national wastewater discharge standard; the concentrated solution of the second-stage nanofiltration membrane is returned to the first-stage nanofiltration membrane; the recycling of useful substances in wastewater and waste water cleaning treatment. The invention does not add any chemical agent in the treatment process, does not produce new pollution, achieves zero discharge, and recovers useful substances, and the treatment process is at normal temperature, and the energy consumption is low.

Description

technical field [0001] The invention relates to the treatment of wastewater containing surfactants, in particular to a method for treating wastewater containing low-concentration perfluorooctanoic acid ammonium. Background technique [0002] When the dispersion method is used to produce PTFE resin, a certain amount of dispersant ammonium perfluorooctanoate (PFOA) must be added, and finally the wastewater with low concentration of ammonium perfluorooctanoate is discharged out of the system. Ammonium perfluorooctanoate is an expensive and efficient surfactant, which is difficult to biodegrade and has great harm to the environment. Therefore, it is both economically and socially meaningful to treat wastewater to recover ammonium perfluorooctanoate. Existing processing method has: distillation recovery method, its shortcoming is that energy consumption is high, uneconomical; of waste solids. Contents of the invention [0003] In order to treat waste water economically and e...

AI Technical Summary

Problems solved by technology

Existing processing method has: distillation recovery method, its shortcoming is that energy consumption is high, uneconomical; waste solids