Perconcentration of Mercury (II) from Natural Water by Activated Charcol -loaded Schiff’s Base 2-Propylpiperidine-1-Carbodithioate (PPCD) Phases

Activated Charcol phase loaded with 2-propylpiperidine-1-carbodithioate (PPCD) were synthesized based on chemical binding and physical adsorption approaches. The stability of a chemically modified PPCD especially in concentrated hydrochloric acid which was then used as a recycling and pre-concentration reagent for further uses of activated Charcol immobilized PPCD. The application of this activated Charcol for sorption of a series of metal ions was performed by using different controlling factors such as the pH of metal ion solution and the equilibration shaking time by the static technique. This difference was interpreted on the basis of selectivity incorporated in these sulfur containing activated Charcol phases. Hg (II) was found to exhibit the highest affinity towards extraction by these activated Charcol phases. The pronounced selectivity was also confirmed from the determined distribution coefficient (Kd) of all the metal ions, showing the highest value reported for mercury (II) to occur by activated Charcol immobilized PPCD phase. The potential applications of activated Charcol  immobilized PPCD phase for selective extraction of mercury(II) to occur from aqueous solution were successfully accomplished as well as pre- concentration of low concentration of Hg(II) (40 pg ml-1) from natural tap water with a pre-concentration factor of 200 for Hg(II) off-line analysis by cold vapor atomic absorption analysis.