Extraction of lactic acid by means of a mixed extractant

Equilibrium studies on the extraction of lactic acid by means of a mixed extractant (a mixture of tri-n-octylamine and Aliquat 336 in decanol) are carried out. Different ratios between the two extractants are investigated, and the obtained results are compared with those using the individual extractants. The effect of the initial pH of the aqueous solution on the extraction extent is. followed in a large interval. The equilibrium pH values are also measured. The obtained results give grounds to conclude that the mixture of a tertiary amine and a quaternary ammonium salt is more efficient than the individual extractants. This makes it particularly appropriate for the recovery of lactic acid from fermentation broth.