Metal ion retention properties of poly(acrylic acid) and poly[N‐3‐(dimethylamino)propyl acrylamide‐co‐acrylic acid]

The crosslinked resins poly(acrylic acid) (PAA) and poly[N‐3‐(dimethylamino)propyl acrylamide‐co‐acrylic acid] [P(NDAPA‐co‐AA)] are obtained by radical polymerization and characterized by FTIR spectroscopy. PAA at basic pH exists basically as an acrylate anion that may contain end carboxylate groups or form bridges acting as mono‐ or bidentate ligands. P(NDAPA‐co‐AA) presents three potential ligand groups in its structure: carboxylic acid, amide, and amine. The trace metal ion retention properties of these two resins is compared by using the batch equilibrium procedure. The metal ions are contained in saline aqueous solutions and are found in natural seawater. The retention of Cu(II), Pb(II), Cd(II), and Ni(II) metal ions is studied under competitive and noncompetitive conditions. The effects on the pH, contact time, amount of adsorbent, temperature, and salinity are investigated. The PAA resin presents a high affinity (>80%) for Cu(II) and Cd(II) ions. The P(NDAPA‐co‐AA) resin shows a high affinity for Pb(II) and Cd(II) ions. With 4M HNO₃ it is possible to completely recover the PAA resin charged with Cu(II) ions and the P(NDAPA‐co‐AA) resin charged with Pb(II) ions. The two resins show a high affinity for Cd(II) ions from the seawater containing Cu(II) and Cd(II) ions. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1385–1394, 2005     

Trace metal ion retention properties of crosslinked poly(4‐vinylpyridine) and poly(acrylic acid)

The crosslinked resins poly(4‐vinylpiridine) (PVPy) and poly(acrylic acid) (PAA) were obtained by radical polymerization. PVPy shows monodentate ligands and PAA at basic pH is basically as acrylate anion, which can contain end‐carboxylates groups or form a bridge acting as mono‐ or bidentate ligands. The retention properties for trace metal ions from saline aqueous solutions and natural seawaters of these two resins were investigated by Batch equilibrium procedure. The metal ions studied were Cu(II), Pb(II), Cd(II), and Ni(II). The following effects were studied: pH, contact time, amount of the adsorbent, temperature, and salinity. The resin PVPy showed a high affinity for Cd(II) and PAA for Cu(II) and Cd(II). The metal ions were determined in the filtrate by atomic absorption spectrometry. By the treatment of the loaded resin with 4M HNO₃, it was possible to remove completely the Cu(II) ions. The retention properties of the resins were studied for trace metal ions present in the natural seawaters. Both resins showed a high affinity for Cd(II) when the natural seawater contained Cu(II) and Cd(II). © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2908–2916, 2004     

Removal properties of crosslinked poly(2‐acrylamido glycolic acid) for trace heavy metal ions: Effect of pH,temperature, contact time,and salinity on the adsorption behavior

Crosslinked poly(2‐acrylamido glycolic acid) resin was synthesized by radical polymerization. This resin contains three potential ligand groups and was studied as an adsorbent of trace heavy metal ions from a saline aqueous solution and sea water by using the Batch equilibrium procedure. Adsorption characteristics of the resin toward Cu(II), Ni(II), Cd(II), and Pb(II) were studied spectrophotometrically, both in competitive and noncompetitive conditions. The effect of pH, contact time, amount of sorbent, temperature, and salinity were studied. The resin showed a high affinity particularly for Ni(II). It was possible to remove completely Ni(II) and Pb(II) from the resin by 4M HNO₃. The retention properties of the resin were also investigated for Cu(II) contained in natural sea waters. The retention behavior was similar to that of the synthetic metal ion aqueous solution. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2614–2621, 2003     

Preparation and adsorption properties of resins containing amine,sulfonic acid,and carboxylic acid moieties

Completely water‐insoluble resins containing amine, carboxylic acid, and sulfonic acid as ligand groups were synthesized by radical polymerization in solution. The yield was higher than 97%. The resins were characterized by FTIR spectroscopy and thermal analysis. The metal ion retention properties at different pH values were investigated by a batch method. Metal ions studied were: Cu(II), Cd(II), Zn(II), Hg(II), Pb(II), and Cr(III). The metal ion binding ability depended strongly on the pH. The retention properties were also tested under competitive conditions. Elution of the metal ion was investigated in acid medium at different concentrations. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 700–705, 2003     

CHARACTERIZATION AND EVALUATION OF LEVEXTREL EXTRACTION CHROMATOGRAPHIC RESINS FOR TRACE METAL SEPARATION SCHEMES IN AUTOMATIC WATER QUALITY CONTROL SYSTEMS.

ABSTRACT

This paper presents the results of the selective removal of Zn(II) from Cu(II), Cd(II), Ni(II) and Pb(II) using ‘Extraction Chromatographic Resins’ Lewatit TP80T84, which contains dK2,4,4-trimethylpentyl)pbosphinic acid as active component. The extraction and selectivity patterns of the resin were obtained from the metal distribution coefficients as a fiinction of pH. Experimental data of Pb(II), Ni(II) and other natural water occurring metal ions, such as Ca(II), were analyzed graphically and numerically in order to describe the metal extraction reactions. Analysis of the results showed that the extraction of these metal ions can be explained assuming the formation of metal complexes in the resin phase with a general composition ML2(_{q 3}HL)q, where q takes different values depending on the metal studied. Finally the efficiency of the resin in the selective removal of Zn(II) from the toxic heavy metal group Cu(T±), Cd(II), Ni(II) and Pb(II) were evaluated.of divalent metal ions (Zn(II), Cu(II), Cd(n), Ni(II), Pb(n)). Concerning the extraction selectivity of Lewatit TP80784 resins versus Zn(II), Cu(II)( Cd(n), Ca(n), Pb(n) and Ni(II), no differences have been found in comparison with the selectivity of this extractant in organic solvents (36). The results of the numerical treatment indicate that the extraction of Pb(n) and Ni(II) can be explained by assuming the formation of PbL₂(HL₂ and NiL₂(HL)₂. However, the extraction of Ca(II) can be explained assuming the formation of two species CaL₂ and Ca(NO₃)L|The analysis of the separation factors indicates that Lewatit TP80784 allows a quantitative separation of Zn(II) from Cd(II), Ni(II) and Pb(II) with ApHso greater that 2 and quasi-quantitative separations (90-95%) from Cu(II)|The results obtained in the extraction of Zn(IT), Cu(H), Cd(II), Ni(II), and Pb(n) from water samples in column experiments are very satisfactory, and the sytem will be used on-line in a multicomponent spectrophotometric method for the monitoring of low levels of toxic metal ions in surface waters.     

Removal of metal ions in aqueous solutions by organic polymers: use of a polydiphenylamine resin

Adsorption of Ni(II), Cu(II), Zn(II), Pb(II) and Cd(II) ions on a polydiphenylamine resin prepared at a strongly oxidizing controlled potential of 3.2 V (vs. ECS) was studied in aqueous solutions. The optimum sorption conditions were determined. The optimum pH for the removal of metal ions was between 4 and 6 for Ni(II), 6 for Cu(II) and Pb(II) and 5 for Zn(II) and Cd(II). The total sorption capacity of the resin was 57.3 mg g⁻¹ for Ni(II), 23 mg g⁻¹ for Cu(II), 36.9 mg g⁻¹ for Zn(II), 19 mg g⁻¹ for Pb(II) and 24.5 mg g⁻¹ for Cd(II). The sorption capacity was compared with other conventional chelating polymers. The sorption kinetics was fairly rapid, as apparent from the loading half time (t_1/2) values, indicating a better accessibility of the chelating sites. The study of the selectivity of the metal ions in the binary solutions shows that the resin presents a higher affinity for the ions of nickel (II).     

Preparation of amidoximated polyester fiber and competitive adsorption of some heavy metal ions from aqueous solution onto this fiber

In this study, a fibrous adsorbent containing amidoxime groups was prepared by graft copolymerization of acrylonitrile (AN) onto poly(ethylene terephthalate) (PET) fibers using benzoyl peroxide (Bz₂O₂) as initiator in aqueous solution, and subsequent chemical modification of cyano groups by reaction with hydroxylamine hydrochloride in methanol. The grafted and modified fibers were characterized by FTIR, TGA, SEM, and XRD analysis. The crystallinity increased, but thermal stability decreased with grafting and amidoximation. The removal of Cu(II), Ni(II), Co(II), Pb(II), and Cd(II) ions from aqueous solution onto chelating fibers were studied using batch adsorption method. These properties were investigated under competitive conditions. The effects of the pH, contact time, and initial ion concentration on the removal percentage of ions were studied. The results show that the adsorption rate of metal ions followed the given order Co(II) > Pb(II) > Cd(II) > Ni(II) > Cu(II). The percentage removal of ions increased with initial ion concentration, shaking time, and pH of the medium. Total metal ion removal capacity was 49.75 mg/g fiber on amidoximated fiber. It was observed that amidoximated fibers can be regenerated by acid without losing their activity, and it is more selective for Pb(II) ions in the mixed solution of Pb‐Cu‐Ni–Co‐Cd at pH 4. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Polyelectrolyte‐assisted removal of metal ions with ultrafiltration

The water‐soluble polymers poly(styrene sulfonic acid‐co‐maleic acid) and poly(acrylic acid‐co‐maleic acid) were investigated with respect to their metal‐ion‐binding ability with ultrafiltration. The studied metal ions included Ag(I), Cu(II), Ni(II), Co(II), Ca(II), Mg(II), Pb(II), Cd(II), Zn(II), Al(III), and Cr(III) ions. The retention properties of the polyelectrolytes for the metal ions depended strongly on the ligand type. As for the carboxylate ligands, with increasing concentration and pH, the metal‐binding affinity increased. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 95: 1091–1099, 2005     

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     

Resin. III. Synthesis,characterization, and ion-exchange properties of a 2,2′-dihydroxybiphenyl–formaldehyde copolymer resin

A 2,2′-dihydroxybiphenyl–formaldehyde copolymer, synthesized by the condensation of 2,2′-dihydroxybiphenyl with CH₂O in the presence of an acid catalyst, proved to be a selective chelating ion-exchange copolymer for certain metals. The chelating ion-exchange properties of this copolymer were studied for Fe(III), Cu(II), Ni(II), Zn(II), Cd(II), and Pb(II) ions. A batch equilibrium method was employed in the study of the selectivity of metal ion uptake, involving the measurements of the distribution of a given metal ion between the copolymer sample and the solution containing the metal ion. The study was carried out over a wide pH range and in media of various ionic strengths. The copolymer showed a higher selectivity for Fe(III), Cu(II), and Ni(II) ions than for Co(II), Zn(II), Cd(II), and Pb(II) ions. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Utilization of peanut shells as adsorbents for selected metals

Peanut shells of mesh size 10–20 were modified by combinations of treatments following a 3² factorial design. Treatments consisted of either no wash, water wash or base wash followed by no modification or modification with 0.6 M citric acid or 0.6 M phosphoric acid. The nine samples were evaluated for their uptake of five metal ions (Cd(II), Cu(II), Ni(II), Pb(II) and Zn(II)) from solution. The results were compared with metal ion adsorption by three commercial cation exchange resins, namely, Amberlite® 200, Amberlite® IRC 718 and Duolite® GT‐73. The percent of metal ions adsorbed per gram of adsorbent was significantly increased by each of the acid treatments, average values ranged from 19 to 34% compared with non‐acid treated samples at 5.7%. The percent of metal ions adsorbed for base‐washed samples were higher than water‐washed or unwashed shells. Interaction between wash and acid treatment was not significant for most of the experimental conditions used. Acid‐treated samples were as effective as Duolite® GT‐73 in the adsorption of Cd(II) and almost twice as effective in the adsorption of Zn(II) from solutions containing a single metal ion. In solutions containing multiple metal ions, citric acid samples were found to be most effective and selective for Cu(II) compared with Cd(II), Ni(II), and Zn(II). In general, phosphoric acid‐modified shells removed the most metals from solution for the experimental samples and were more effective in removing Cd(II) and Zn(II) than two of the three commercial resins. Acid‐modified peanut shells are promising as metal ion adsorbents. © 1999 Society of Chemical Industry     

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     

A New Sorbent for Selective Separation of Metal: Polyethylenimine Methylenephosphonic Acid

Abstract

A new sorbent, the polyethylenimine methylenephosphonic acid (PEIMPA), was synthesized from commercially available polyethylenimine. After characterization by (¹H, ¹³C, ³¹P) NMR, elementary analysis, UV/VIS and FTIR, the new ion exchange polymer PEIMPA has been investigated in liquid – solid extraction of a mixture of Cd(II), Co(II), Cu(II), Fe(III), Ni(II), Pb(II), and Zn(II) cations from a mineral residue of zinc ore dissolved in nitric acid. The selectivity of this polymer was studied as a function of pH. PEIMPA can sorb much higher amounts of Fe ion than Cd, Co, Cu, Ni, Pb, and Zn ions. The recovery of Fe(III) is almost quantitative. Because of this remarkable affinity, the PEIMPA resin has the potential for application in several fields. Further studies of the polymer are in progress.     

Heavy metals adsorption on some iminodiacetate chelating resins as a function of the adsorption parameters

The adsorption properties of some novel chelating resins (CRs) bearing iminodiacetate groups for removal of heavy metal ions like: Cu(II), Co(II) and Ni(II) from aqueous solutions comparative with the commercial resin Amberlite IRC-748 have been studied in this work by a batch equilibrium technique. Quantitative analysis for adsorption was conducted using UV–vis spectroscopy to investigate the kinetics, adsorption isotherm and thermodynamics of the removal process considering equilibration time, pH, metal ion concentration and temperature as controlling parameters. The metal adsorption capacities, at pH 5, were in the order Cu(II) > Ni(II) > Co(II), for both the CR with 10 wt.% DVB (CR-10) and the commercial resin Amberlite IRC-748. The adsorption capacities on CR-10 were higher for Ni(II) and Co(II) ions, but lower for Cu(II) ions compared with Amberlite IRC-748. Both Freundlich and Langmuir isotherms well fitted on the adsorption results of Cu(II), Ni(II) and Co(II) ions on all iminodiacetate resins.     

Poly(2-acrylamido glycolic acid): A water-soluble polymer with ability to interact with metal ions in homogenous phase

A water-soluble polymer, poly(2-acrylamido glycolic acid) was obtained by radical polymerization and characterized by FT-IR, ¹H NMR, and ¹³C NMR spectroscopy. The metal ion retention properties were investigated through the liquid-phase polymer based retention (LPR) technique at different pHs and filtration factor Z. The affinity of the ligand groups for the metal ions depends strongly on the pH. At lower pH, the retention is lower than 50%, which increased as the pH increased. At pH 5, the polymer showed a high affinity and selectivity for Pb(II), and at pH 7 the P(AGA) formed stable complexes with Cu(II), Co(II), Ni(II), Cd(II), and Pb(II). Of the three potential ligand groups, amide, hydroxyl, and carboxylate groups, the carboxylate groups form the more stable complexes with the metal ions.     

Synthesis of 1,4,8,11‐tetraazacyclotetradecane monomer by addition of acryloyl chloride and its polymer for specific transition metal binding

1,4,8,11‐Tetraazacyclotetradecane (cyclam) was reacted with acryloyl chloride in a 1 : 2 molar ratio in dichloromethane in the presence of pyridine at 0°C. The modified cyclam was polymerized by adding an azobisisobutyronitrile initiator and irradiated with a UV lamp under reflux for 6 h. Precipitated cyclam containing polymer in the bulk structure was removed from the suspension by filtration. After washing and drying the final polymeric materials were used for transition metal ion adsorption and desorption studies. A Fourier transform IR spectrophotometer and thermogravimetric analyzer were used to characterize the polymeric structure. The affinity of the polymeric material for transition metal ions was used to test the adsorption–desorption of selected ions [Cu(II), Ni(II), Co(II), Cd(II), Pb(II)] from aqueous media containing different amounts of these metal ions (5–800 ppm) at different pH values (2.0–8.0). It was found that the adsorption rates were high and the adsorption equilibrium was reached in about 30 min. The uptake of the transition metal ions onto the polymer from solutions containing a single metal ion was 3.17 mmol/g for Cu(II), 0.98 mmol/g for Cd(II), 0.79 mmol/g for Co(II), 0.78 mmol/g for Ni(II), and 0.32 mmol/g for Pb(II). This polymer showed high affinity for Cu(II) compared to the other metal ions in the single ion solution and in the mixture of transition metal ions. The affinity order of the transition metal ions was Cu(II) ? Ni(II) > Cd(II) > Co(II) > Pb(II) for competitive adsorption. More than 95% of the adsorbed transition metal ions were desorbed in 2 h in a desorption medium containing 1.0M HNO₃. Poly(cyclam) was found to be suitable for repeated use of more than five cycles without a noticeable loss of adsorption capacity. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1406–1414, 2002     

Water‐soluble amine and imine polymers with the ability to bind metal ions in conjunction with membrane filtration

The commercial polymers poly(ethylene imine) (PEI), poly(ethylene imine epichlorohydrin), and poly(dimethylamine‐co‐epichlorohydrin) were purified and fractionated by ultrafiltration. Their metal‐ion‐binding properties with respect to different ligand groups and the effect of the concentration on the retention properties were investigated. The amine ligands of the polymers formed the most stable complexes with the metal ions. In general, there was an effect of the pH and polymer fraction size on the retention properties. As the pH and polymer fraction size increased, the affinity to bind metal ions also increased. PEI had the highest metal‐retention values, particularly at higher pHs, at which the amine groups were nonprotonated and could coordinate easily with the metal ions. Only Pb(II) was poorly retained. The affinity for all the metal ions, except Pb(II), increased significantly at pH 5. The metal‐ion retention decreased quickly as the filtration factor increased, except for Cu(II), Co(II), Ni(II), Cd(II), and Zn(II) ions, which were retained by over 40% at a filtration factor of 4. For other metal ions such as Pb(II), Ca(II), and Mg(II), only 10% remained bound to the polymer. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 222–231, 2005     

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.     

Investigation of Heavy Metal Ion Adsorption Characteristics of Poly(N,N Dimethylamino Ethylmethacrylate) Hydrogels

Abstract

In this study, Poly(N,N dimethyl‐amino ethylmethacrylate) (Poly(DMAEMA)) hydrogels with varying compositions were prepared in the form of rods by irradiating ternary mixtures of N,N‐dimethylamino ethylmethacrylate/ethyleneglycoldimethacrylate/water with gamma rays at ambient temperature. Swelling studies of poly (DMAEMA) hydrogels were performed at different pH values and maximum swelling values reached at pH 2. The adsorption characteristics of Pb(II), Cd(II), Ni(II), Zn(II), Cu(II), and Co(II) ions to poly(N,N dimethylamino ethylmethacrylate) hydrogels were investigated by a batch process. The order of affinity based on amount of metal ion uptake was found as follows: Cu(II)>Zn(II)?Co(II)>Pb(II) >> Ni(II)>Cd(II). In the adsorption studies of Cu(II), Zn(II), Co(II), Pb(II), Ni(II), and Cd(II) ions the Langmuir type adsorption isotherms were observed for all gel systems.     

Selective removal of some heavy metal ions from aqueous solution using treated polyethylene-g-styrene/maleic anhydride membranes

Radiation graft copolymerization of styrene/maleic anhydride (Sty/MAn) comonomer onto low density polyethylene (LDPE) membrane was investigated. The prepared grafted membranes were treated with different reagents containing various functional groups and studied as a matrix for the purpose of water purification from heavy metals. The metal ion uptake by the functional groups of membranes was determined by the use of X-ray fluorescence (XRF) and atomic absorption (AA). The effect of pH of the metal feed solution and immersion period needed for maximum capacity was investigated. The selectivity of different prepared membranes towards some selected metal ions such as Fe, Cu, Pb,… etc. which commonly exist in waste water was determined. The affinity of the treated grafted films to recover Fe(III), Cu(II) or Pb(II) from their aqueous solutions containing other metal ions such as Cd(II), Ni(II) or Hg(II) was studied. Also the selectivity of treated grafted membranes towards Cu(II), Cr(III) and Fe(III) in a mixture was investigated at room temperature and 70°C. It was found that the thiosemicarbazide-, hydroxylamine·HCl- and NaOH-treated grafted films showed high selectivity towards Cu(II), Cr(III) and Fe(III), respectively, at 70°C. However, the selectivity of such treated grafted membranes was remarkable towards Fe(III) at room temperature. The results obtained suggested that the treated grafted membrane possessed good chelating properties towards different metal ions. This suggests that such membranes could be accepted for practical uses.