Heavy metal ions removal through poly(acrylamide-co-methacrylic acid) resin

The resin poly(acrylamide-co-methacrylic acid) P(AAm-co-MA) by radical polymerization was synthesized and its metal ion binding was studied using the batch and column equilibrium procedures for: Cd(II), Zn(II), Pb(II), Hg(II), Al(III), and Cr(III). Experiments were carried out at different pH, metal ion concentration, temperature, and contact time. The resin’s retention behavior was influenced by the pH. The highest retention 91% (0.248 mmol/g, 6.7 mg/g) was achieved at pH 5 for Al(III), and 87% (0.265 mmol/g, 54.9 mg/g) for Pb(II). For Hg(II), the yield was 85% (0.318 mmol/g, 63.7 mg/g) at pH 2. The metal-ion retention properties were dependent on the polymer/metal ion ratio. Under competitive conditions of Pb(II), Hg(II), and Al(III), the resin showed a higher retention of Hg(II), allowing the selective separation of this metal.     

Metal ion sorption properties of water-insoluble resins based on sodium styrene sulfonate and different comonomers

A set of water-insoluble resins based on sodium styrene sulfonate and different comonomers were synthesized. The resins poly(mono-2-(methacryloyloxy)ethyl succinate-co-sodium 4-styrene sulfonate) P(MOES-co-SSNa), poly(2-acrylamido glycolic acid-co-sodium 4-styrene sulfonate) P(AGA-co-SSNa), poly(acrylamide-co-sodium 4-styrene sulfonate) P(AAm-co-SSNa), and poly(2-(dimethylamine)ethyl acrylate-co-sodium 4-styrene sulfonate) P(DMAEA-co-SSNa) were synthesized by solution radical polymerization. The metal ion retention properties were studied by batch procedure for Cd(II), Zn(II), Pb(II), and Hg(II). Resins performance was compared with a poly(sodium 4-styrene sulfonate) (PSSNa) resin in order to evaluate the effect of comonomer on sorption properties. The effect of pH, time, temperature, and maximum retention capacity were studied. In addition, sorption experiments were carried out under competitive ion conditions to study the selectivity of resins. The resins P(AAm-co-SSNa) and P(AGA-co-SSNa), showed the most important differences compared with PSSNa resin, the former present higher sorption and the latter presented selectivity for Hg(II) at pH 2.     

Free radical copolymerization of functional water-soluble poly(N-maleoylglycine-co-crotonic acid): polymer metal ion retention capacity, electrochemical, and thermal behavior

In this study, the water-soluble polymers of N-maleoyl glycine (MG) with crotonic acid (CA) were copolymerized by free radical polymerization to obtain hydrophilic polymers, in order to study the effect of the functional groups in the copolymers on the metal ion retention capacity, electrochemical and thermal behavior, since that important requirements for their use in technological applications are: high solubility in water, chemical stability, a high affinity for one or more metal ions, and selectivity for the metal ion of interest. The metal complexation properties of poly(MG-co-CA) for the metal ions were investigated at pH 3, 5, and 7 in aqueous solution. The metal ion investigated were: Cu(II), Co(II), Cr(III), Ni(II), Cd(II), Zn(II), and Fe(III). The polymeric systems showed high metal ion retention for Zn (II) and Fe(III) at different pH. At different pHs, the MRC of the poly(MG-co-CA) for Fe(III) ions varied from 122.1 to 146.2 mg/g and from 120.5 to 133.5 mg/g, (samples 1 and 2 at pH 3 and 7, respectively). The MRC had the highest retention values for both copolymer systems at pH 7. The copolymers presented higher thermal decomposition temperature (TDT) in comparison with copolymer–metal complexes at pH 3 and 5. The cyclic voltammetry (CV) for poly(MG-co-CA) (20 mM) was compared with the CV of the [poly(MG-co-CA)–Fe(III)] copolymer complex. Moreover, [poly(MG-co-CA)–Fe(III)] showed a redox wave difference between +0.25 and +0.50 V possibly due to the presence of metal complexed with the polymer. The electrochemical characterization of the copolymer poly(MG-co-AC) shown the reduction of carboxylic acid groups of the N-maleoylglycine and crotonic acid moiety to hydroxyl group. The results support the assumption that the copolymer presents convenient electroactivity.     

Modification of Malonamide Ion-Exchange/Chelating Resins Using the Fields–Kabatschnik Reaction and Their Application to Metal Ion Removal from Aqueous Solutions

A resin containing 2-aminoethyl-substituted amides of malonic acid was modified in the Fields–Kabatschnik reaction using diethyl phosphite. The resultant ion-exchange/chelating resins have aminomethylphosphonate groups. Modification proceeds almost quantitatively, giving a resin with P=1.97 mmol/g, N=4.20 mmol/g, and water regain of 0.44 g/g. It can be selectively hydrolyzed by treatment with trimethylchlorosilane/potassium bromide in dry acetonitrile. Both acidic and ester forms of the resin were used in the removal of Cu(II), Cd(II), Ni(II), and Zn(II) from their diluted 1×10^–4 N solutions in 0.2 M acetate buffer at pH 3.7 and 5.6. The affinity of the resin in an acid form toward divalent metal cations is high, and at pH 5.6 the log K _d is 7.54, 3.97, 3.41, and 3.98, respectively. The resins are selective and the presence of an excess of sodium ions does not influence the uptake of metal ions. The type of complexes formed between the resins and Cu(II) ions was studied using EPR spectroscopy. The ester form of the resin was used in the removal of tetrachloroaurate anions from hydrochloric acid solution. It has been found that the log K _d is in the range of 3.14–3.94 for the uptake of AuCl^– ₄ from 5.0–0.5 M HCl solutions.     

Preparation of bifunctional chelating fiber containing iminodi(methylphosphonate) and sulfonate and its performances in column-mode uptake of Cu(II) and Zn(II)

The bifunctional chelating fiber, FNPS, was prepared from vinylbenzyl chloride (CMS) grafted polyethylene-coated polypropylene fiber (PPPEf-g-CMS). In addition to the primary iminodi(methylphosphonate) chelating groups, FNPS has sulfonate groups as secondary functional group. FNPS was prepared by the following four steps. First, PPPEf-g-CMS was reacted with potassium phthalimide to substitute chlorine atoms in PPPEf-g-CMS with phthalimide groups. Second, sulfonate groups were introduced into the phenyl groups of benzyl moieties on the grafted polymer chains by the reaction with 95% sulfuric acid. Third, phthalimide moieties were hydrolyzed with ethanol solution of hydrazine hydrate to give the primary amino groups at the end of benzyl moieties on the grafted chains. Finally, these primary amino groups were converted into iminodi(methylphosphonate) groups by Mannich condensation reaction, in which the precursory fiber was reacted with large excess phosphorous acid and paraformaldehyde in 6 M hydrochloric acid media under the refluxed conditions for 6 h. The sulfonate and iminodi(methylphosphonate) groups in the resulting FNPS were identified by FT-IR spectroscopy. Contents of nitrogen, phosphorus, and sulfur in FNPS were found to be 1.53, 2.80, and 0.99 mmol/g, respectively. The phosphorus to nitrogen molar ratio was 1.83. This is very close to the ideal value of 2. The sulfur to nitrogen molar ratio was 0.65. The column-mode test on the Cu(II) uptake from a 0.1 mM Cu(II) aqueous solution revealed that FNPS can take up Cu(II) rapidly even in the extremely high feed flow rate range from 1000 to 7000 h^?1 in space velocity. The breakthrough capacity of FNPS for Cu(II) is as high as ca. 0.8 mmol/g at the flow rate of 7000 h^?1. In addition, it is expected that the FNPS packed column will make it possible to purify huge volumes of waters contaminated with 10^?4 M levels of Zn(II), as long as the concentrations of the co-existing Ca(II) and Mg(II) are nearly equal to those in river waters.     

Reaction with metal ions of chloromethylated polystyrene resin containing dithiocarbamate group

The derivatives of poly(chloromethylstyrene) resin (PCMS) with N-methyl-N-carboxylmethyl-dithiocarbamate (1), N,N-di(β-hydroxyethyl)dithiocarbamate (2), N-methyl-N-carboxylmethylamino (3), and di(β-hydroxyethyl)amino (4) groups were prepared, and the metal ion reactivity of the polymer resins with these functional groups were investigated. Additionally, the effect of γ irradiation on the reaction with metal ion was also investigated. In the reaction of PCMS under the same conditions, the substitution ratio order is as follows: (2) > (1) > (4) > (3). In the reaction of the resins with cupric ion, the reaction amount reached a maximum of 4.17 mequiv/g for resin (1) and 4.75 mequiv/g for (2). The polymers containing sulfur atom have a large reactivity toward metal ion in comparison to the polymers without sulfur atom. The reactivity of polymer (1) toward metal ions decreased in the following order: Ag(I) ? Cu(II)> Zn(II) ? Ni(II) ? Co(II). The other metal ions, except Ag(I) and Cu(II), hardly reacted with polymer (2). Thus, polymer (2) has a remarkable selectivity. It was also found that the reaction amount of polymers containing sulfur after γ irradiation is almost the same as that before γ irradiation.     

Separation of metal ions by water‐insoluble polymers containing sulfonic/sulfonate groups

A water‐insoluble polymer, poly(sodium 4‐styrene sulfonate), was synthesized by radical polymerization at different amounts (2, 4, 6, and 8 mol %) of crosslinking reagent (CR). At the lowest CR level (2 mol %), only a water‐soluble polymer is obtained, and consequently it could not be studied as resin. The polymerization yield ranged from 82.6 to 91.6%. The resin is characterized by FTIR spectroscopy, thermal analysis, and scanning electron microscopy. The metal ion affinity is studied for the cations: Hg(II), Cd(II), Zn(II), Pb(II), Cr(III), and Al(III) with a batch equilibrium procedure under different experimental conditions. The metal ion affinity increased as the pH increased. At pH 5, the resin showed an affinity greater than 97% for all metal ions. Hg(II) showed the highest retention value at pH 2. The maximum retention capacity is determined at optimum pH for Hg(II), Cd(II), Pb(II), and Zn(II). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4328–4333, 2006     

EVALUATION OF A DIETHANOLAMINE CHELATING RESIN USING TWO-PHASE POTENTIOMETRY

ABSTRACT

The synthesis of a polystyrene resin functionalised with diethanolamine is described. Protonation of the resin and complexation of Pb(II), Cd(II), Hg(II), UO₂ ²⁺, Fe(III), Ca(n) and Nd(III) were studied using two-phase potentiometry. From these experiments, apparent formation constants could be calculated and distribution curves obtained. Predictions as to metal ion separations were then possible. Batch experiments with Eu(III) and Pu(IV) were also performed as well as a column experiment for Pb(II) and Ca(II) to test selectivity. The resin shows selectivity towards metal ions that are large and/or have a good affinity for nitrogen donor ligands. Metal ions susceptible to hydrolysis are well complexed by the resin due to its ability to suppress hydrolysis.     

Sulfonamide based polymeric sorbents for selective mercury extraction

New polymeric resin with sulfonamide pendant functions have been prepared for the selective extraction of mercuric ions. This polystyrene sulfonamide resin with a 3.5 mmol/g total nitrogen content is able to selectively sorb mercury from aqueous solutions.The mercury sorption capacity of the resins are around 1.71 mmol/g for acetyl sulfonamide resin and 2.9 mmol/g for methanesulfonyl sulfonamide resin under non-buffered conditions. The experiments performed under identical conditions with some metal ions reveal that Cd(II), Pb(II), Zn(II) and Fe(III) ions are also extractable in low quantity (0.05–0.1 mmol/g). The mercury-loaded polymers (acetyl sulfonamide and methanesulfonyl sulfonamide) may be quantitatively regenerated with hot acetic acid and 4 M HNO₃.     

Analytical applications of newly synthesized copolymer resin derived from p‐aminophenol,dithiooxamide, and formaldehyde

A copolymer resin (p‐APDF) has been synthesized using the monomers p‐aminophenol, dithiooxamide, formaldehyde in 1 : 1 : 2M proportions in the presence of 2M HCl as catalyst. The structure of p‐APDF copolymer has been elucidated on the basis of elemental analysis and various physicochemical techniques, i.e., UV‐visible, FTIR, and ¹H‐NMR spectroscopy. The number average molecular weight of copolymer resin was determined by nonaqueous conductometric titration in DMF. Viscosity measurement were carried out in DMF indicate normal behavior. The prepared resin proved to be a selective ion exchange resin for some metal ions. The chelating ion exchange properties of this resin was studied for Fe(III) and Cu(II), Ni(II), Co(II), Zn(II), Cd(II), Pb(II) ions. A batch equilibrium method was used to study selectivity of metal ion uptake over a wide pH range and in media of various ionic strength. The resin showed a higher selectivity for Fe(III), Ni(II), Cu(II) ions than for Co(II), Pb(II), Zn(II), and Cd(II) ions. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Separation and concentration of trace Pb(II) by the porous resin loaded with α-zirconium phosphate crystals

Crystalline α-zirconium phosphate (α-ZrP) has been loaded in the pores of porous spherical polymer beads by impregnation of ZrOCl₂ · 8H₂O and hydrolysis of the zirconium salt followed by the hydrothermal reaction with phosphoric acid. The physicochemical properties of the α-ZrP loaded resin have been investigated in terms of X-ray diffraction, pore distribution, surface area and the distribution of α-ZrP in the polymer beads. The scanning electron microscope observation indicates that α-ZrP crystals distribute uniformly in the resin pore. The adsorption characteristics of the α-ZrP resin for the metal ions including Pb(II), Cd(II), Cu(II), Zn(II), Fe(III), Al(III) and Ca(II) have been examined. The present resin has revealed unexpectedly high selectivity toward the adsorption of Pb(II) and hence, interference from common metal ions (Na⁺, Ca²⁺) is not significant. Due to the remarkable selectivity, fast kinetics and chemical stability, the present α-ZrP resin has been effectively applied to the separation and enrichment of trace Pb(II) from aqueous solution.     

Poly(4-sodium styrene sulfonate-co-4-acryloylmorpholine). Synthesis,Characterization, and Metal Ion Retention Properties

Abstract

A novel resin poly(sodium 4-styrene sulfonate-co-4-acryloyl morpholine) was synthesized through a radical solution polymerization in solution and studied as an adsorbent under uncompetitive and competitive conditions by batch and column equilibrium procedures for the following divalent metal ions Cd(II), Zn(II), Pb(II), and Hg(II), and trivalent Cr(III). For all metal ions, the adsorption was strongly influenced by the pH. The maximum retention capacity, 3.29 mmol of metal ion/g, was obtained for Zn(II) at pH 5 by batch equilibrium procedure. For both the batch and column procedures, the retention behavior was similar for Cd(II), Cr(III), Zn(II), and Pb(II).     

Resins containing amino and carboxylic acid groups. Synthesis,characterization, and metal ion retention properties

The crosslinked poly[3‐(methacryloylamino)propyl]dimethyl(3‐sulfopropyl)ammonium hydroxide], P(MAPDSA), and poly[3‐(methacryloylamino)propyl]dimethyl(3‐sulfopropyl)ammonium hydroxide‐co‐acrylic acid], P(MAPDSA‐co‐AA), were synthesized by radical polymerization. The resins were completely insoluble in water. Due to the lower metal ion retention of P(MAPDSA), the metal ions investigated under competitive and noncompetitive conditions for Cu(II), Cd(II), Hg(II), Zn(II), Pb(II), and Cr(III) ions by batch and column equilibrium procedures were carried out only for P(MAPDA‐co‐AA), particularly for Hg(II). The resin–Hg(II) ion equilibrium was achieved before 15 min. The resin showed a maximum retention capacity value for Hg(II) at pH 2 of 1.89 meq/g. The resin showed a high selectivity to Hg(II) ions. The recovery of the resin was investigated at 25°C with different concentrations of HNO₃ and HClO₄. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 525–530, 2005     

PREPARATION AND ADSORPTION PROPERTIES OF THE POLYSTYRENE RESIN HAVING DIETHYLENETRIAMINE-N,N′- BIS(METHYLENEPHOSPHONATE) GROUP

Styrene-divinylbenzene copolymer beads containing diethylenetriamine-N,N′-bis(methylenephosphonate) group have been synthesized. The adsorption properties, of the present resin for some trivalent and bivalent metal ions have been examined. The selectivity sequence of the present resin at pH lower than 2.0 is as follows: Ga(III)> A1(III)> Sm(III)>Cu(II)>Co(II)>Zn(II)>Ca(II). The present resin reveals remarkable selectivity for the trivalent metal ions. The selective concentration of In(III) Ga(III) and Sm(III) from an acidic aqueous solution has been demonstrated by using a column of the present resin.     

MECHANISM OF POLYMER-BASED SEPARATIONS. III. METAL ION LOADING CAPACITIES OF REACTIVE POLYMERS WITH SPECIFIC RECOGNITION MECHANISMS

The metal ion selectivity series displayed by a reactive polymer, the phosphinic acid ion exchange/redox resin, was determined from equinormal solutions of 1 milliequivalent metal ion per milliequivalent of polymer ligand sites and compared to results from trace ion solutions. It was found that intervention by the recognition mechanism (i.e., reduction) with Hg(II) and Ag(I) ions from pH 2 aqueous solutions led to high resin loading capacities. Thus, the phosphinic resin/Hg(II) interaction displayed a log D of 3.88, compared to 3.80 from a 10^-4 N solution, indicating that the recognition mechanism obviated any influence of a loading effect. The loading effect was apparent in Fe(III) complexatign wherein a log D of 4.94 was found from a 10^-4 N solution and 0.40 from the equinormal solution. The solution acidity was also an important determinant of selectivity: the series was Fe > Hg > Mn > Ag from 4N HNO₃ and Hg > Ag > Mn > Fe from 0.01N HN0₃. The performance of the phosphinic acid resin was contrasted to that from the non-reactive (i.e., solely ion exchanging) phosphonic acid resin.     

Novel chelating resins with aminothiophosphonate ligands

Metal chelating resins containing aminothiophosphonate ligands were synthesised from two types of starting polymers: vinylbenzyl chloride/divinylbenzene and more polar acrylonitrile/ethyl acrylate/divinylbenzene. Both polymers were first modified with amines (ethylenediamine and diethylenetriamine) and subsequently reacted with diethyl thiophosphonochloridate. The resin based on the more polar polymer, containing 2.61 mmol/g phosphorus and 5.52 mmol/g nitrogen, modified with ethylenediamine was selected as the most promising for Cd/Ni separation. Sorption studies have been performed with 10⁻⁴ M Cd(II) and Ni(II) solutions in 0.2 M acetate buffer in the pH range 3.7–5.6. It has been found that the aminothiophosphonate resin is highly specific for Cd (log K_d=4–5), whereas Ni sorption is negligible. This new resin is compared with a commercial metal chelating polymer resin, Purolite S950, containing aminomethylphosphonate ligands.     

High‐retention properties for Hg(II) ions of a resin containing ammonium and pyridine groups

The metal‐ion uptake behavior of the chelating resin poly([(3‐(methacryloylamino)propyl] trimethyl ammonium chloride‐co‐4‐vinyl pyridine) has been investigated. The resin is obtained by radical copolymerization in a yield of 99.6%. The hydrophilic resin shows a high retention capacity and selectivity toward Hg(II) ions in the presence of Cu(II), Pb(II), Cd(II), Zn(II), and Cr(III) ions. A retention of Hg(II) higher than 99% is observed after 5 min. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2595–2599, 2002     

Properties of bifunctional phosphonate fibers derived from chloromethylstyrene grafted polyolefin fibers

Bifunctional fibers containing phosphonate and sulfonate were derived from chloromethylstyrene grafted polyolefin fibers (PPPE-g-CMS) by phosphorylation and subsequent sulfonation reactions. It was clarified that phosphorylation of PPPE-g-CMS by Arbusov reaction is more suitable than one by the reaction with PCl₃ in the presence of AlCl₃, because the latter damaged fibers and gave phosphinate groups in addition to phosphonate ones. Then, bifunctional fibers containing phosphonate and sulfonate groups were prepared by sulfonation of monofunctional phosphonate fibers obtained via Arbusov reaction with chlorosulfonic acid. The metal ion selectivity of the bifunctional fibers was governed by both phosphonate and sulfonate groups. In addition, bifunctional fibers gave much more excellent kinetic performances in column-mode uptake of Cu(II) than the monofunctional phosphonate fibers and resin.     

Resin I: Synthesis,characterization, and ion‐exchange properties of terpolymer resins derived from 2,4‐dihydroxypropiophenone,biuret, and formaldehyde

Terpolymers (2,4‐DHPBF) were synthesized by the condensation of 2,4‐dihydro‐xypropiophenone, biuret, and formaldehyde in the presence of acid catalyst with varying the molar ratio of reacting monomers. Terpolymer composition has been determined on the basis of their elemental analysis and their number–average molecular weight of these resin were determined by conductometric titration in nonaqueous medium. The viscosity measurements were carried out in N,N‐dimethyl formamide which indicate normal behavior. IR spectra were studied to elucidate the structure. The terpolymer resin has been further characterized by UV–visible and ¹H‐NMR spectra. The newly synthesized terpolymers proved to be selective chelating ion‐exchange terpolymers for certain metals. The chelating ion‐exchange properties of this terpolymer was studied for Fe (III), Cu (II), Hg (II), Cd (II), Co (II), Zn (II), Ni (II), and Pb (II) ions. A batch equilibrium method was employed in the study of the selectivity of metal ion uptake involving the measurement of the distribution of a given metal ion between the terpolymer sample and a solution containing the metal ion. The study was carried out over a wide pH range and in media of various ionic strengths. The terpolymer showed a higher selectivity for Fe (III), Hg (II), Cd (II), and Pb (II) ions than for Cu (II), Co (II), Zn (II), and Ni (II) ions. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Metal‐ion‐retention properties of the poly(2‐acrylamido‐2‐methyl‐1‐propanosulfonic acid‐co‐4‐vinyl pyridine) resin

The water‐insoluble resin poly(2‐acrylamido‐2‐methyl‐1‐propanosulfonic acid‐co‐4‐vinyl pyridine), through a radical polymerization solution, was synthesized with ammonium persulfate as an initiator and N,N‐methylene bisacrylamide as a crosslinking reagent. The metal‐ion‐retention properties were studied by batch and column equilibrium procedures for the following metal ions: Hg(II), Cu(II), Cd(II), Zn(II), Pb(II), and Cr(III). These properties were investigated under competitive and noncompetitive conditions. The effects of the pH, maximum retention capacity, and regeneration capacity were studied. The resin showed a high retention ability for Hg(II) ions at pH 2.0. The retention of Hg(II) ions from a mixture of ions was greater than 90%. The resin showed a high selectivity for Hg(II) with respect to other metal ions. The Hg(II)‐loaded resin was able to be recovered with 4M HClO₄. The retention capacity was kept after four cycles of adsorption and desorption. The retention properties for Hg(II) were very similar with the batch and column methods. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3556–3562, 2003