EXTRACTION MECHANISM OF PHENOL BY SULFURIC ACID SALTS OF TRIOCTYLAMINE

In the present study, the extraction mechanism of phenol from an aqueous solution by sulfuric acid salts of trioctylamine (TOA salts) was investigated. Based on the experimental evidence that the affinity of sulfuric acid and amine is greater than that of phenol and amine, the procedure of the extraction mechanism is assumed to involve two independent steps, i.e., trioctylamine (TOA) is first reacted with sulfuric acid to form TOA salts and phenol is extracted from the aqueous phase by TOA salts. The Wilson model, which accounts for the reaction of trioctylamine and sulfuric acid to form different kinds of TOA-salts, is employed to predict the extraction of phenol in the present study. The number of water molecules in the neighborhood of the different TOA-salts, which directly reflects the extraction capability of phenol, was determined. This prediction from the Wilson model is fairly consistent with the experimental data.