Mass-transfer model of mercury removal from water via microemulsion liquid membranes

Mercury extraction in a stirred tank reactor was modelled using experimentally determined equilibrium extraction, stripping and reaction kinetics. The microemulsion employed was obtained by equilibrating tetradecane containing oleic acid and a surfactant with the sulphuric acid stripping reagent phase, to form droplets having a mean Sauter diameter of 0.014-0.017 mm, as compared with 0.5-1 mm for coarse emulsion systems. Model simulations suggested that as the pH of the feed solution containing the mercury(II) increased, the final equilibrium mercury concentration decreased, although the initial extraction rate was not affected by the pH. There are 31 references.