Separation of Carboxylic Acids from Waste Water via Reactive Extraction

The separation (or removal) of organic residues from aqueous waste streams released from industries is important and essential from the points of view of pollution control and recovery of useful materials. The disposal of waste waters containing most widely-used industrial organic acids such as acetic acid, formic acid and propionic acid has been recognized as a significant expense to the industry and environment. This paper presents a state-of-the-art review on the development of techniques for the separation of carboxylic acids from waste water. Available conventional techniques including fractional distillation, liquid extraction, adsorption, precipitation, ion exchange, etc. have been discussed emphasizing the major drawbacks of these methods. A new method – reactive extraction for extracting carboxylic acids from dilute aqueous solutions using a chemical extractant is described and compared with the other conventional techniques. Reactive extraction is an efficient, economical, and environmental friendly method for separation of acids from waste water streams.