Removal of concentrated heavy metal ions from aqueous solutions using polymers with enriched amidoxime groups

Abstract

Particulate and fibrous adsorbents with enriched amidoxime groups were synthesized by using a novel monomer N,NЈ-dipropionitrile acrylamide. The adsorption properties of amidoximated poly(N,NЈ-dipropionitrile acrylamide) [poly(DPAAm)] particles and a nonwoven fabric grafted with the same for UO 2 2ϩ , Pb 2ϩ , Cu 2ϩ, and Co 2ϩ at high concentrations were investigated by batch process. Metal ion adsorption studies were conducted from metal ion solutions with different initial concentrations (100 -1500 ppm). It was shown that particulated amidoximated poly-(DPAAm) has higher adsorption capacity than amidoximated nonwoven fabrics for all metal ions, especially for uranyl ions. The results of the adsorption studies showed that the interaction between UO 2 2ϩ and amidoximated groups agree with the Langmuir-type isotherm. From the Langmuir equation, the adsorption capacities were found as 400 mg UO 2 2ϩ /g dry amidoximated poly(DPAAm) and 250 mg UO 2 2ϩ /g dry amidoximated graft polymer.

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

“…This type of adsorption behavior in the later stage is typical of the specific adsorption process in which the adsorption rate is dependent upon the number of available adsorption sites on the surfaces of the adsorbent and the amount of adsorption is usually controlled by the attachment of the metal ions on the surfaces, most probably through the chelating interaction mechanism. The amount of metal ions adsorbed increased with increase in contact time and reached equilibrium after 24 hr and remained uniform throughout the 48 h. The adsorption behavior of metal ions is directly related to some experimental factors such as pH, characteristics and porosity of the hydrogel, dimensions of the metal ion, and the properties of the donor ligands (15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34).…”

“…UV-induced crosslinking can be preferred over the wet chemical crosslinking when fast curing rate, little side products, low heat productions, and homogeneous network formation are demanded. 19 The main advantage of hydrogel sorbents is their easy loading and complexation ability via carboxyl, amine, amino acid, amidoxime, imidazole, thiol, pyridine, and triazole functional groups on their structure (19,(21)(22)(23)(24)(25)(26)(27). The metal ion chelating polymers with nitrogen-containing complex ligands have a great adsorption capacity for polyvalent metal cations owing to the strong affinity between the nitrogen atom and metal cations (27).…”

Novel heavy-metal adsorption material: ion-recognition P(NIPAM-co-BCAm) hydrogels for removal of lead(II) ions

“…In the past few decades, a large number of cross-linked polymeric materials and chemically modified biosorbents have been reported to be used as adsorbents for removal of lead ions from aqueous solutions. These adsorbent materials usually incorporate various metal-complexing ligands including carboxyl, amide, amino acid, amidoxime, imidazole, thiol, pyridine, and triazole functional groups [12][13][14][15][16][17][18][19][20]. However, how to release the adsorbed lead ions from the adsorbents, which causes a decrease in the adsorption capacity, remains a major issue for currently existing ligand adsorption techniques.…”

Sorption of uranyl ions from aqueous solutions using crosslinked maleic anhydride‐octene‐styrene terpolymer

“…The extraction of uranyl ions by structured hydrogels composed of acrylamide-maleic acid and acrylamide -acrylic acid systems has been studied. 4,5 The sorption of uranyl ions on modified chitosan resins has been studied by atomic absorption spectroscopy, 6,7 whereby the sorption degree was found to be 90-93%. The sorption of urany ions on polyethylene glycol-methylacrylic acid hydrogels has been compared with that on polymethylacrylic acid homopolymer.…”