METHOD AND APPARATUS FOR TREATING WASTE WATER CONTAINING ACETIC ACID

PURPOSE:To carry out separation and recovery of acetic acid in waste water in good efficiency by a method wherein a permeate obtained after the waste water containing acetic acid is subjected to reverse osmosis treatment is contacted with a non-polar molecular adsorbing agent as well as a regenerated liquid of the adsorbing agent is returned to a reverse osmosis treatment process. CONSTITUTION:An alkali liquid is introduced into waste water containing acetic acid stored in a raw water tank 1 from an alkali tank 5 to adjust pH thereof to 6 or more. The waste water after pH adjustment is introduced into a reverse osmosis module 2 through a pump to be separated into a concentrated liquid and a permeate. The concentrated liquid is sent to a recovery tower 3 and acetic acid therein is recovered herein. Acetic acid present in the permeate is present almost in a form of CH3COOH and said permeate is introduced into an adsorbing tower 4. In the acetic acid adsorbing tower 4, an adsorbing agent adsorbing non-polar molecule is packed and acetic acid in an aqueous solution is adsorbed thereto. A regenerating liquid of the tower 4 is returned to the alkali tank 5 for pH adjustment through a line 9.