Removal of mercury species with dithiocarbamate-anchored polymer/organosmectite composites

The primary aim of this study was to investigate performance of dithiocarbamate-anchored polymer/organosmectite composites as sorbents for removal of mercury from aqueous solution. The modified smectite nanocomposites then were reacted with carbondisulfide to incorporate dithiocarbamate functional groups into the nanolayer of the organoclay. These dithiocarbamate-anchored composites were used for the removal of mercury species [Hg(II), CH3Hg(I) and C6H5Hg(I)]. Mercury adsorption was found to be dependent on the solution pH, mercury concentration and the type of mercury species to be adsorbed. The maximum adsorption capacities were equal to 157.3 mg g−1 (782.5 μmol g−1) for Hg(II); 214.6 mg g−1 (993.9 μmol g−1) for CH3Hg(I); 90.3 mg g−1 (325 μmol g−1) for C6H5Hg(I). The competitive adsorption capacities (i.e. adsorption capacities based on solutions containing all three mercuric ions) are 7.7 mg g−l (38.3 μmol g−1), 9.2 mg g−l (42.6 μmol g−1) and 12.7 mg g−1 (45.7 μmol g−1) for Hg(II), CH3Hg(I) and C6H5Hg(I), respectively, at 10 ppm initial concentration. The adsorption capacities on molar basis were in order of C6H5Hg(I) > CH3Hg(I) > Hg(II).