Removal of Mercury from Wastewater of a Chlor-Alkali Unit by Foam Fractionation

An experimental investigation is presented on batch foam fractionation of mercury ion from acidic dilute aqueous solutions with various types of surfactants. The employed surfactants are cationic (cetyl trimethyl ammonium bromide), anionic (sodium lauryl sulfate) and nonionic (Triton x-100). The experimental evidences show that Triton x-100 is less effective for separation of mercury ions than the others. The effects of different parameters like: surfactants concentration, initial concentration of mercury ions, gas flow rate, pH and sodium ion concentration on the removal of mercury ions have been studied. The obtained results indicate that higher surfactant concentration; lower initial mercury ion concentration and higher gas flow rate will increase the rate of separating of mercury ions. The optimum pH for the removal of mercury ions was found to be 1.8. The presence of sodium ions will interfere in the adsorption of mercury ions on the bubble surface and causes the mercury removal efficiency to be decreased.

Keywords:

Mercury , Foam , Wastewater , Fractionation , Chlor-Alkali