SYNTHESIS OF THIOL CHELATING RESINS AND THEIR ADSORPTION PROPERTIES TOWARD HEAVY-METAL IONS

A series of chelating resins, derived from a macroreticular styrene-di vinylbenzene (2%) copolymer beads grafted with various poly(ethylene g lycols) HO-(-CH2 -CH2-0-)n-H (n = 0, 4, 9, 13) and containing thiol gr oups as chelating functions, have been synthesized in a three-step rea ction sequence. The structure of the functionalized resins was confirm ed by IR spectrophotometry, elemental analysis, and differential scann ing calorimetry. The complexation behavior of these thiol resins was i nvestigated towards Hg(II), Cu(II), and Pb(II) ions in aqueous solutio n by a batch equilibration technique. The influence of pH on adsorptio n capacity was also examined. The adsorption values for metal ions' in take followed the order Hg(II) > Cu(II) > Pb(II). The affinity of thes e polymers towards Hg(II) ions was so high that the total mercury leve l in the liquid decreased from 20 ppm to below 10 ppb after 2 h of tre atment. Polymers can be regenerated by washing with a solution of hydr ochloric acid (6N) and 10% by weight of an aqueous solution of thioure a. (C) 1994 John Wiley & Sons, inc.