Removal of dyes and heavy metal ions from water by magnetic hydrogel beads based on poly(vinyl alcohol)/carboxymethyl starch-g-poly(vinyl imidazole)

Abstract

Table of contents entryHighly porous magnetic nanocomposite hydrogel (m-CVP) beads were prepared and used for the removal of dyes and heavy metal ions. AbstractNovel magnetic nanocomposite hydrogel (m-CVP) beads were prepared by instantaneous gelation of carboxymethyl starch-g-polyvinyl imidazole (CMS-g-PVI), poly(vinyl alcohol) (PVA), and Fe 3 O 4 mixture in boric acid solution followed crosslinking by glutaraldehyde (GA). Highly porous m-CVP beads with magnetic sensitivity were fully characterized and used as eco-friendly absorbent for removal of crystal violet (CV) and congo red (CR) dye and Pb(II), Cu(II) and Cd(II) from water. Batch adsorption results showed that the sorbent had high affinity to the heavy metals and dyes in water. The adsorption kinetics results showed that the adsorption rates could be described by pseudosecond-order kinetics indicating chemical sorption at rate determining step. Sorption of Pb(II), Cu(II), Cd(II), CR and CV to m-CVP beads agreed well to the Langmuir adsorption model at different ionic strengths with the maximum adsorption capacity of 65.00, 83.60, 53.20, 83.66 and 91.58 mg g -1 , respectively. Positive values of ∆H 0 showed that the adsorption was chemisorption, and the negative values of ∆G 0 indicated the spontaneity of the pollutant adsorption. Desorption and reusability of m-CVP beads was also investigated for tested heavy metal ions and dyes based on sequential adsorptiondesorption cycles. All the studied results indicated that m-CVP beads were an efficient, low cost, and reusable adsorbent for removal of dye and heavy metal ions from aqueous solutions.

Preparation of poly(vinylalcohol)/poly(acrylamide-co-vinyl imidazole)/γ-Fe2O3semi-IPN nanocomposite and their application for removal of heavy metal ions from water

“…The Pb(II) and Cd(II) adsorption removal could maintain more than 80% and 75% at the fourth cycle, respectively. The leaching of Fe ions from magnetic semi‐IPN hydrogel after exposure in 25 ml 0f 0.01 M HNO 3 solutions for several days was investigated according to the previous report . The amount of released Fe ions was only 2.911 ± 0.194, 3.594 ± 0.409, and 4.232 ± 0.323 mg l −1 after 24‐, 48‐, and 72‐hr exposure, respectively.…”

“…The leaching of Fe ions from magnetic semi-IPN hydrogel after exposure in 25 ml 0f 0.01 M HNO 3 solutions for several days was investigated according to the previous report. [39] The amount of released Fe ions was only 2.911 ± 0.194, 3.594 ± 0.409, and 4.232 ± 0.323 mg l À1 after 24-, 48-, and 72-hr exposure, respectively. Therefore, magnetic semi-IPN hydrogel can be employed repeatedly for Pb(II) and Cd(II) metal removal from aqueous solution.…”

Synthesis of amino‐cosubstituted polyorganophosphazenes and fabrication of their nanoparticles for anticancer drug delivery

“…[60] FT-IR (KBr, thin film, cm −1 ): 3226 (C C N and C C H stretching vibration), 1,512 (C C stretching vibration) and 963 ( CH stretching vibration) of EAB. [62] of EAB and GEE. [63,64] 1,020 (P N stretching vibration) and 962 (P N stretching vibration) of polyphosphazenes backbone.…”

Preparation of dithiocarbamate polymer brush grafted nanocomposites for rapid and enhanced capture of heavy metal ions

“…16,17 In order to improve the adsorbent performance, organic chelating ligands have been developed based on imidazole, thiol, dithiocarbamate (DTC), and thiourea, or carbonyl groups. 18,19 It is particularly worth mentioning that the high affinity for metallic ions is a unique characteristic of sulfur containing groups, especially in case of the DTC group. [20][21][22] DTC group is well-known to be an so Lewis base, which could form stable complexes with heavy metal ions (so Lewis acids) containing partially and fully lled d orbitals through p-coordinated interactions.…”