Removal of mercury from aqueous solutions by adsorption on a new ultra stable mesoporous adsorbent and on a commercial ion exchange resin

Background: The performance of two adsorbents, i.e. a new ultra stable adsorbent SH-ePMO and a commercial ion exchange resin TP-214, for the removal of mercury from aqueous solutions was investigated. The operating variables studied were initial mercury concentration and contact time. Results: The adsorption isotherms showed favourable adsorption. The adsorption isotherms were analysed using Langmuir and Freundlich models. The Langmuir model yielded the best fit for the SH-ePMO, whereas the Freundlich model fitted best the adsorption on TP-214. The maximum adsorption capacities were 66 and 456 mg/g for SH-ePMO and TP-214, respectively. TP-214 is capable of purifying water to parts per trillion levels. The adsorption kinetics showed a fast adsorption for both adsorbents. The kinetics was analysed using Lagergren s pseudo-first-order and pseudo-second-order kinetic models. The pseudo-first-order kinetic model showed a good description of the experimental data of both adsorbents. Conclusions: This study clearly shows the potential of the ultra stable SH-ePMO for removing mercury from aqueous solutions and confirms the performance of the ion exchanger resin TP-214.