Uptake of Pb²⁺UsingN-Vinyl Imidazole Based Uniform Porous Hydrogels

Abstract

The uniform porous and continuous phase lead (II) adsorbent hydrogel, was prepared by copolymerizing 2-hydroxyethyl methacrylate (HEMA), acrylic acid (AAc), and N,N 0 -methylenebisacrylamide (MBAAm), with n-vinyl imidazole (VIM). A series of hydrogels, including different ratios of VIM, were prepared by photopolymerization and characterized. The influence of the uptake conditions such as pH, functional monomer percent, contact time, initial feed concentration, and foreign metal ions on the metal ion binding capacity of hydrogel, were also tested. The selective chelation of heavy metal ions from synthetic wastewater was also studied. The affinity order on molar basis was observed as follows: Pb (II) > Zn (II) > Cd (II). Chelation behavior of heavy metal ions could be modelled using both the Langmuir and Freundlich isotherms and it was seen that the Langmuir isotherm model was the best fit for the adsorption of Pb (II) ions in P(VIM/AAc/HEMA) hydrogel. Moreover, the limits of detection and the quantification values were determined. Regeneration of the hydrogels was easily performed with 1 M HCl and the same hydrogel can be reused five times almost without any loss of adsorption capacity. All these features make P(VIM/AAc/HEMA) hydrogels potential candidate adsorbent for heavy metal removal.

Microfibrillated cellulose reinforced poly(vinyl imidazole) cryogels for continuous removal of heavy metals

“…The structure of the poly(VIM)/MFC cryogel was analyzed by FTIR spectra shown in Figure 3(a). The characteristic stretching vibration bands of VIM appeared at around 1230 cm −1 (NCN), 1110 cm −1 (ring vibration), 1082 cm −1 (in‐plane ring CH bending), and 918 cm −1 (ring deformation), suggesting the polymerization of VIM into the cryogels 48,49 . The bands at 1726 cm −1 and 1662 cm −1 were assigned to the stretching vibration of the carbonyl group of HEMA and MBA, respectively 35,50 .…”

“…The characteristic stretching vibration bands of VIM appeared at around 1230 cm À1 (N C N), 1110 cm À1 (ring vibration), 1082 cm À1 (in-plane ring C H bending), and 918 cm À1 (ring deformation), suggesting the polymerization of VIM into the cryogels. 48,49 The bands at 1726 cm À1 and 1662 cm À1 were assigned to the stretching vibration of the carbonyl group of HEMA and MBA, respectively. 35,50 The results demonstrated the polymerization of HEMA and MBA into the poly(VIM-HEMA) cryogel and MBA into the poly(VIM)/MFC cryogel.…”

Removal of heavy metal ions from aqueous solution by superabsorbent poly (NIPAAm/DAPB/AA) amphoteric nanohydrogel

“…2. FT-IR spectra explain the interaction between metal ions and functional groups of nanohydrogels, in which some bands were disappeared and shifting in certain peaks was observed [21]. The characteristic peak of N-H bond at 2,975 cm −1 was shifted to some lower frequency in both the metal ions-adsorbed nanohydrogels, indicating the participation of the -NH groups in adsorption.…”