Effect of pH and temperature on Hg2+ water decontamination using ETS-4 titanosilicate

Batch stirred tank experiments were carried out to study the effect of pH (range 2-10, at 294 K) and temperature (277, 294 and 313 K, at pH 5) on the uptake of Hg(2+) ions by ETS-4 microporous titanosilicate. Changes in the pH have a significant effect on the ETS-4 uptake efficiency, the optimal range being 4-6. Due to competition effects, the chemical used to adjust the pH of the Hg(2+) solution also influences the uptake efficiency. Thermodynamic parameters for the uptake of Hg(2+) ions were calculated. For the temperature range studied, the Hg(2+) sorption increased with decreasing temperature.