The removal of toxic metals from liquid effluents by ion exchange resins. Part XII: Mercury(II) /H+/Lewatit SP112

Mercury(II) was eliminated, from acidic aqueous solutions, by the cationic ion exchange resin Lewatit SP112. Various experimental conditions were tested in the investigation, such as, stirring speed (275-1000 min), temperature (20-60 °C), pH of the aqueous solution (0-4) and resin dosage (0.05-0.4 g·L). Mercury(II) uptake onto the resin decreased with the increase of the temperature (exothermic reaction) in a spontaneous process, whereas the moving boundary model represented the metal uptake in the 20-60 °C temperatures range. Moreover, the experimental data fitted to the second order kinetic model (275 min) or the pseudo-second order kinetic model (500-1000 min), though maximum metal uptake was not dependent on the stirring speed applied to the system. The experimental results responded well to the Langmuir type-2 isotherm. The Hg(II)-loading ability of Lewatit SP112 was compared against that of other resins and non-functionalized multiwalled carbon nanotubes. Mercury(II) loaded onto the resin can be eluted by means of various eluants, furher, zero valent mercury was yielded from the eluates.To the CSIC (Spain) for support. To Mrs. E. Moroño (CENIM) for assistant in the analytical work, and to Prof. Dr. P. Adeva (CENIM) to obtain the images of Fig. 4