EXTRACTION OF AMMONIA FROM A DILUTE AQUEOUS-SOLUTION BY EMULSION LIQUID MEMBRANES .2. THEORY AND MASS-TRANSFER MODEL

A mass-transfer model built with an immobilized hollow spherical globule configuration and gross film theory is being proposed to interpret the laboratory data of ammonia extraction from a dilute aqueous solution by emulsion liquid membrane (ELM) technology. The model assumes acid-base reaction equilibrium to exist in both internal droplet and external aqueous phases. The effect of solute leakage due to membrane rupture (in terms of a time-varying leakage function) has been considered to account for the reverse transport of ammonia back into the external phase (Figure 3), which adversely affects the extraction efficiency. The theory and model computations can predict fairly well the general trends of extraction phenomena in the batch system operations described in part 1. © 1990, American Chemical Society. All rights reserved.