Process for the recovery of carboxylic acid, in particular acetic acid containing carboxylic anhydride in particularacetic anhydride and other impurities, which comprises: (a) treating a fraction, in particular a fraction originating from a wood treatment process, containing carboxylic acid and impurities with a metal salt in the presence of water, (b) treating at least part of the fraction obtained from step (a) to remove metal salt and, (c) treating at least part of the fraction obtained from step (b) by distillation, stripping or membrane separation to recover at least a purified carboxylic acid fraction.