Separation of Hg(II) by foam fractionation in the acidic range: Effect of complexation

Experimental results indicated that the efficiency of mercury removal closely correlates with pH as well as the concentration of positively charged mercury-containing species. They also indicated that this efficiency is higher at lower Hg concentrations. A removal efficiency of ∼80% was resulted for solutions containing 2.5 × 10−5 M Hg in highly acidic media. It was noticed that this efficiency would drop almost to zero as pH was raised to around 5.5. The theoretical findings were in close agreement with the experimental results.