Novel methacryloylamidophenylalanine functionalized porous chelating beads for adsorption of heavy metal ions

Abstract

ABSTRACT:The purpose of this study was to investigate in detail the adsorption performance of poly(2-hydroxyethylmethacrylatemethacryloylamidophenylalanine) [p(HEMA-MAPA)] beads. The metal-complexing comonomer MAPA was synthesized by reacting methacryloyl chloride with phenylalanine. Spherical beads with an average size of 150-200 m were obtained by radical suspension polymerization of HEMA and MAPA, conducted in an aqueous dispersion medium. The beads had a specific surface ADSORPTION OF HEAVY METAL IONSarea of 19.1 m 2 /g, and were characterized by means of swelling studies, FTIR, and elemental analysis. Beads with a swelling ratio of 68% and containing 3.2 mmol MAPA/g were used for the removal of heavy metal ions. Adsorption experiments were conducted with the MAPA-functionalized beads involving the heavy metal ions cadmium, arsenic, chromium, mercury, and lead. Metal adsorption was found to be dependent on the characteristics of the solution (i.e., medium pH and metal concentration) and the type of metals to be adsorbed. We have obtained adsorption capacities equal to 669.4 mg/g for Hg(II), 584.4 mg/g for Pb(II), 268.4 mg/g for Cd(II), 204.1 mg/g for As(III), and 115.2 mg/g for Cr(III). The adsorption capacities on molar basis were in the order of Hg(II) > Pb(II) > Cd(II) > As(III) > Cr(III). Adsorption of heavy metal ions from synthetic wastewater was also studied. The adsorption capacities were 24.5 mg/g for Cd(II), 16.9 mg/g for Cr(III), 144.4 mg/g for Hg(II), 90.9 mg/g for Pb(II), and 8.0 mg/g for As(III) at 0.5 mmol/l initial metal concentration. Naturally, depending on the desired goals, the beads containing metal could be regenerated for appropriate disposal. Our results suggest that p(HEMA-MAPA) beads are good metal adsorbers and have a great potential for environmental protection.

Cr(III)-imprinted polymeric beads: Sorption and preconcentration studies

“…The pollutant is adsorbed onto the solid adsorbent surface from the effluent with the quantity of the removed pollutant depending on the adsorption capacity of the sorbent [17]. The need of more selective system for separation of metal ions has been increased the development of the synthesis of new extractants and sorbents [18][19][20][21][22][23][24][25]. One of the recently developed tecniques for the preparation of solid phase is the ion-selective imprinting technique that could be used for selective separation and preconcentration of trace metals [26][27][28].…”

Porous polymer particles—A comprehensive guide to synthesis, characterization, functionalization and applications

“…On the other hand, non-ionic porous resins are also used in catalysis [403][404]. The catalyst is either a covalently attached organic molecule [405] or a metal that is chelated to the resin thanks to the electron donating ligands [406][407][408][409][410]. Simple precipitation of the metal to the pores is also reported [411][412].…”

Porous dye affinity beads for nickel adsorption from aqueous solutions: A kinetic study

“…They did not dissolve in aqueous media but did swell, depending on the degree of crosslinking. 22 The equilibrium swelling ratio (the ratio of the weights of the beads before and after swelling) of the beads was 55%. These swollen beads had an average diameter within the range of 150 -250 m. These dye-attached beads were suitable for packed or fluidized bed column applications.…”