Recovery of Picolinic Acid from Aqueous Streams Using a Tertiary Amine Extractant

Abstract

Solvent extraction using an extractant/diluent system was determined for the recovery of picolinic acid. Trioctylamine (TOA) was used as the extractant and alcohols (isoamyl alcohol and 1-hexanol), esters (ethyl acetate and propyl acetate), and hydrocarbons (n-heptane and toluene) as the diluents. TOA gives a complex with the acid resulting in an acid-amine complex which is solvated by the diluents. On the basis of results from batch extraction experiments, a mass-action analysis was introduced for modeling extraction. The experimental results of batch extraction experiments are reported as distribution coefficients, (K(D) = (C*(PA)/C(PA))), loading factors, Z, and extraction efficiency, E. The highest synergistic extraction efficiency was found to be 96.620 for the TOA + isoamyl alcohol extractant system with a K(D) value of 28.587 and Z value of 0.588.