PURIFICATION OF WASTEWATER CONTAINING ACETIC ACID BY USING ICE PLATE CRYSTALLIZER

摘要

A method for refining wastewater containing acetic acid is provided to separate and recover acetic acid from wastewater containing low-concentration acetic acid simply and efficiently, by using a plate type ice crystallizer. Wastewater containing 0.01-10 wt% of low-concentration acetic acid is cooled to a temperature of -10-0°C at a cooling rate of 0.01-10 K/min within a plate ice crystallizer, thereby forming ice crystallizations and enriched acetic acid. The ice crystallizations and the enriched acetic acid are separated from a residual solution. The ice crystallization and enriched acetic acid are heated to a temperature of -5-10°C at a heating rate of 0.01-10 K/min or maintained within the heating temperature, thereby melting the ice crystallizations to separate water and the enriched acetic acid. DI water is sprayed on a surface of the ice crystallizations while the ice crystallizations are melted, thereby separately recovering refined discharge water and the enriched acetic acids. Further, the ice crystallizations have needle-shape.