Metal-organic framework DUT-67 (Zr) for adsorptive removal of trace Hg2+ and CH3Hg+ in water

Abstract

A Zr-based stable metal-organic frameworks DUT-67 (Zr) was successfully synthesized as an adsorbent to remove trace mercury and methylmercury ions in aqueous solution. The removal efficiency of 90% and 55% of Hg2+ and CH3Hg+ was respectively achieved at pH 6 and 55°C. The S in thiophene has a relatively weak adsorption capacity for mercury and there could be the slight π-complexation between thiophere ring of DUT-67 (Zr) and Hg2+ besides physical absorption, while there only was physical adsorption between DUT-67 (Zr) and CH3Hg+. The developed methods were applied to remove trace Hg2+ and CH3Hg+ in the real water samples, and the removal efficiency was from 69% to 90% and from 30% to 77% respectively; when the concentrations of Hg2+ was lower than 20 μg L−1 in the samples, the remaining mercury concentration was lower than 1 μg L−1，which can meet the standard of the World Health Organization.

Keywords

• Metal organic framework
• mercury ions
• methylmercury ions
• adsorption