Patent Number: 6,254,779

Title: Treatment of effluent streams containing organic acids

Abstract: An acidic organics-containing waste water stream (12) derived from for example plant for the production of an aromatic carboxylic acid such as terephthalic acid is treated to allow recovery of alkali and water for recycle to the production process. The treatment comprises adjusting the pH of the waste water stream using an alakaline medium, oxidising (10) the organics content of the stream to convert the same to water, carbon dioxide and (bi)carbonate ions, and supplying the treated stream to a reverse osmosis membrane (28, 30) to produce a retentate containing (bi)carbonate ions and cations derived from the alkaline medium and a permeate which is substantially free of those components. The retentate (46) is recycled for use in adjustment of the pH of the waste water stream and, if desired, water-consuming facilities which can tolerate less pure water. The permeate (44) may also be recycled, with or without further treatment, for use in water-consuming facilities within and/or associated with the production plant.

Inventors: Jeffery; Ian Charles (Cleveland, GB), Jackson; Christopher Howard (Cleveland, GB)

Assignee: E. I. du Pont de Nemours and Company

International Classification: B01D 61/02 (20060101); B01D 61/04 (20060101); C02F 9/00 (20060101); C02F 1/44 (20060101); C02F 3/28 (20060101); C07C 51/487 (20060101); C02F 1/04 (20060101); C02F 3/02 (20060101); C07C 51/42 (20060101); C02F 1/66 (20060101); C02F 1/72 (20060101); C02F 1/00 (20060101); C02F 1/78 (20060101); C02F 003/02 (); C02F 001/58 (); C07C 051/16 (); C07C 051/42 ()

Expiration Date: 07/03/2018