The extraction of acetic acid from an aqueous solution into solutions of quaternary amine

Aliquat 336

in different diluent

n-octanol

chloroform and kerosene

was investigated under various pH

concentration of Aliquat 336 and solute.The style of complex formation was discussed

and a model describing the equilibrium was proposed.The distribution coefficient

D

fitted the simple additive property of Aliquat 336 and the diluent.Diluent affected the D apparently; the D in chloroform and kerosene increased quicker than that in n-octanol with the Aliquat 336 concentration in organic phase.There was a maximum value for D against pH

which depended on the Aliquat 336 concentration only

and the pH value responding to the maximum D was 4.0～4.3 and 3.7～4.2 for 25% Aliquat and 50% Aliquat system

respectively.Acetic acid was bonded to Aliquat 336 by both ion exchange and chemical association

and diluent affected their parameters obviously.The apparent constant of ion exchange

K 1

increased in diluent

especially in chloroform.The apparent constant of association

K 2

increased in chloroform also

decreased in n-octanol

and kerosene affected K 2 not apparently.