Batch Equilibrium Procedure Research Articles

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

AbstractA 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

Water‐insoluble polymers containing amine, sulfonic acid, and carboxylic acid groups: Synthesis, characterization, and metal‐ion‐retention properties

AbstractCrosslinked poly(acryloylmorpholine) and its copolymers poly(acryloyl morpholine‐co‐acrylic acid) and poly(acryloylmorpholine‐co‐2‐acrylamide‐2‐methyl‐1‐propane sulfonic acid) were synthesized by radical polymerization. The resins were completely insoluble in water and were characterized with Fourier transform infrared spectroscopy and thermal analysis. The metal ions Ag(I), Cu(II), Cd(II), Hg(II), Zn(II), Pb(II), Al(III), and Cr(III) were investigated under competitive and noncompetitive conditions by a batch equilibrium procedure. The resin‐metal‐ion equilibrium was achieved before 5 min. The recovery of the resin was investigated at 20°C with different concentrations of HNO3 and HClO4. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 99: 3266–3274, 2006

Metal ion retention properties of water‐insoluble polymers containing carboxylic acid groups

AbstractCrosslinked poly(acrylic acid), PAA, and poly(2‐acrylamidoglycolic acid), PAAG, were synthesized by radical polymerization. Both resins contain carboxylic acid groups. PAA at basic pH exists basically as an acrylate anion and PAAG shows three atoms or groups, carboxylic acid, hydroxyl, and amide groups, that can act as ion exchanger or chelating groups. Both resins are studied as adsorbents to trace metal ions from saline aqueous solutions and natural sea water and their properties by Batch equilibrium procedure are compared. The metal ions studied under competitive and noncompetitive conditions were Cu(II), Pb(II), Cd(II), and Ni(II). The effects of pH, time of contact, amount of resin, temperature, and salinity were studied. Resin PAA shows a high affinity (>80%) for Cu(II) and Cd(II) and resin PAAG shows also a high affinity for Ni(II), Pb(II), and Cd(II). By treatment of the metal ion‐loaded resin with 4M HNO3 it is possible to recover completely the Cu(II) ions from resin PAA and Ni(II) and Pb(II) from resin PAAG. The metal ion retention properties were studied with natural sea water. For those natural sea waters containing Cu(II) and Cd(II), the resins showed a high affinity for Cd(II) ions. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 697–705, 2006

Resins with the ability to bind copper and uranyl ions

AbstractCrosslinked poly(1‐vinyl imidazole‐co‐acrylic acid) and crosslinked poly(1‐vinylmidazole‐co‐2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid) were synthesized by radical polymerization and characterized by elemental analysis and FTIR spectroscopy. The polymerization yields were 79 and 99%, respectively. The metal ion binding properties for copper(II) and uranium(VI) were studied under noncompetitive and competitive conditions by Batch equilibrium procedure. The resin crosslinked poly(1‐vinyl imidazole‐co‐acrylic acid) showed a higher dependence on pH than crosslinked poly(1‐vinylmidazole‐co‐2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid). The retention of uranyl ions for the latter resin was close to 100% at pH 5.0. The higher maximum retention capacity was close to 0.8 mmol/g dry resin at pH 5.0. Regeneration of the resin was possible by treatment with basic eluent. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 706–711, 2006

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

AbstractThe 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

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

AbstractThe 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

Adsorption and desorption of metolachlor and metolachlor metabolites in vegetated filter strip and cultivated soil.

Previous studies have indicated that dissolved-phase metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(methoxy-1-methylethyl) acetamide] transported in surface runoff is retained by vegetative filter strips to a greater degree than either metolachlor oxanilic acid 12-[(2-ethyl-6-methylphenyl) (2-methoxy-1-methylethyl)amino]-2-oxo-acetic acid] (OA) or metolachlor ethanesulfonic acid [2-[(2-ethyl-6-methylphenyl) (2-methoxy-1-methylethyl-1)amino]-2-oxoethanesul-fonic acid] (ESA), two primary metabolites of metolachlor. Adsorption-desorption of ESA and OA in vegetated filter strip soil (VFSS) has not been evaluated, yet these data are required to assess the mobility of these compounds in VFSS. The objective of this experiment was to compare metolachlor, ESA, and OA adsorption and desorption parameters between VFSS and cultivated soil (CS). Adsorption and desorption isotherms were determined using the batch equilibrium procedure. With the exception of a 1.7-fold increase in organic carbon content in the VFSS, the evaluated chemical and physical properties of the soils were similar. Sorption coefficients for metolachlor were 88% higher in VFSS than in CS. In contrast, sorption coefficients for ESA and OA were not different between soils. Relative to metolachlor, sorption coefficients for ESA and OA were at least 79% lower in both soils. Metolachlor desorption coefficients were 59% higher in the VFSS than in the CS. Desorption coefficients for ESA and OA were not different between soils. Relative to metolachlor, desorption coefficients for ESA and OA were at least 66% lower in both soils. These data indicate that the mobility of ESA and OA will be greater than metolachlor in both soils. However, higher organic carbon content in VFSS relative to CS may limit the subsequent transport of metolachlor from the vegetated filter strip.

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

AbstractThe 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

Water‐insoluble polymers with ability to remove metal ions

AbstractCrosslinked poly[3‐(methacryloylamino)propyl]dimethyl(3‐sulfopropyl)ammonium hydroxide‐co‐2‐acrylamido glycolic acid [P(MAAPDSA‐co‐AGCO)] was synthesized by radical polymerization and tested as an adsorbent under competitive and noncompetitive conditions for Cu(II), Cd(II), Hg(II), Zn(II), Pb(II), and Cr(III) by batch and column equilibrium procedures. The resin–metal ion equilibrium was achieved before 1 h. The resin showed a maximum retention capacity value for Hg(II) at pH 2 of 1.084 meq/g. The recovery of the resin was investigated at 20°C under different concentrations of HNO3 and HClO4. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3679–3685, 2004

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

AbstractThe 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

Preparation and adsorption properties of the chelating resins containing carboxylic, sulfonic, and imidazole groups

AbstractThe crosslinked poly(1‐vinylimidazole‐co‐acrylic acid), P(VIm‐co‐AA), and poly(1‐vinylimidazole‐co‐2‐acrylamido‐2‐methyl‐1‐propane sulfonic acid) P(VIm‐co‐APSA) were synthesized by radical polymerization and tested as adsorbents under competitive and noncompetitive conditions for Cu(II), Cd(II), Hg(II), Zn(II), Pb(II), and Cr(III) by batch equilibrium procedure. The resin–metal ion equilibrium was achieved before 1 h. The resin P(VIm‐co‐AA) showed a maximum retention capacity (MRC) value for Pb(II) at pH 3 and Hg(II) at pH 1 of 1.1 and 1.2 mEq/g, respectively, and the resin P(VIm‐co‐AA) showed at pH 3 the following MRC values: Hg(II) (1.5 mEq/g), Cd(II) (1.9 mEq/g), Zn(II) (2.7 mEq/g), and Cr(III) (2.8 mEq/g). The recovery of the resin was investigated at 25°C with 1 M and 4 M HNO3 and 1 M and 4 M HClO4. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2852–2856, 2003

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

AbstractCrosslinked 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

Extraction and exchange behavior of metal species in therapeutically applied peat

The binding and availability of metals (Al, Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb, Zn) in therapeutically applied peat (Großes Gifhorner Moor, Sassenburg/North Germany) was characterized by means of a versatile extraction approach. Aqueous extracts of peat were obtained by a standardized batch equilibrium procedure using high-purity water (pH 4.5 and 5.0), 0.01 mol l −1 calcium chloride solution, 0.01 mol l −1 ethylenediaminetetraacetic acid (EDTA) and 0.01 mol l −1 diethylenetriamine pentaacetic acid (DTPA) solution as metal extractants. In addition, the availability of peat-bound metal species was kinetically studied by collecting aliquots of extracts after different periods of extraction time (5, 10, 15, 30, 60 and 120 min). Metal determinations were performed by atomic spectrometry methods (AAS, ICP-OES) and dissolved organic matter (DOM) was characterized by UV/Vis measurements at 254 and 436 nm, respectively. Of the extractants studied Ca, Mg and Mn were the most available metals, in contrast to peat-bound Fe and Al. The relative standard deviation s r of the developed extraction procedures was mostly in the range of 4 to 20%, depending on the metal and its concentration in peat. A pH increase favored the extraction of metals and DOM from peat revealing complex extraction kinetics. Moreover, a competitive exchange between peat-bound metal species and added Cu(II) ions showed that >100 mg of Cu(II) per 50 g wet peat was necessary to exchange the maximum of bound metals (e.g. 21.8% of Al, 3.9% of Fe, 79.0% of Mn, 81.9% of Sr, related to their total content).

Influence of some environmental substances on atrazine adsorption in Baiyangdian lake area soil

Soil environmental substances such as humic acids, nitrates and other organic substances, are major factors affecting adsorption of atrazine in soils. In this paper, the influence of humic acid (HA), dodecylbenzene sulfonic acid sodium salt (SDBS) and NH4NO3 on atrazine adsorption by soils was studied through batch equilibrium procedures and adsorption isotherm methods. The results showed that the Freundlich equation can be used to describe the adsorption isotherm of atrazine in soils. It can be found that the HA and SDBS enhance in varying degrees the adsorption capacity of atrazine in soil, except for NH4NO3.

Sorption properties of poly(styrene‐co‐divinylbenzene) amine functionalized weak resin

The poly(styrene-co-divinylbenzene) amine functionalized weak resin was studied as adsorbent of heavy metal ions from an aqueous solution by using the Batch equilibrium procedure. The resin adsorbed Hg(II) 56% (0.56 mEq/g) at pH 2, and 45% (1.13 mEq/g) of U(VI), 38% (0.36 mEq/g) of Pb(II) at pH 5 from an aqueous solution containing 1 g/L of each metal ion. It did not adsorb Cd(II), Zn(II). The equilibrium time was achieved during the first hour. The maximum load capacity for Hg(II) was 0.8 mEq/g (75 mg)/g dry resin. It is possible to recover around 60% of the resin after the treatment with 1–4 M HClO4 and HNO3 of the loaded Hg(II) resin. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2123–2127, 2001

Sorption properties of poly(styrene‐co‐divinylbenzene) amine functionalized weak resin

AbstractThe poly(styrene‐co‐divinylbenzene) amine functionalized weak resin was studied as adsorbent of heavy metal ions from an aqueous solution by using the Batch equilibrium procedure. The resin adsorbed Hg(II) 56% (0.56 mEq/g) at pH 2, and 45% (1.13 mEq/g) of U(VI), 38% (0.36 mEq/g) of Pb(II) at pH 5 from an aqueous solution containing 1 g/L of each metal ion. It did not adsorb Cd(II), Zn(II). The equilibrium time was achieved during the first hour. The maximum load capacity for Hg(II) was 0.8 mEq/g (75 mg)/g dry resin. It is possible to recover around 60% of the resin after the treatment with 1–4 M HClO4 and HNO3 of the loaded Hg(II) resin. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2123–2127, 2001

Metal ion extraction behavior of poly([2(methacryloyloxy)ethyl]trimethylammonium chloride-co-acrylic acid) resin

The crosslinked poly([2-(methacryloyloxy)ethyl]trimethyl ammonium chloride-co-acrylic acid) was tested as adsorbent for Cd(II), Hg(II), Zn(II), Pb(II), Cr(III), and U(VI) by batch equilibrium procedure. At pH 5.0 the adsorbent retained 74% (1.865 meq/g) of U(VI) with a maximum capacity of load of 2.7 meq/g (108 mg/g). The resin-U(VI) equilibrium was achieved around of 1 h which is considered adequate for a heterogeneous reaction. It showed a high selectivity for U(VI) respect to all the other metal ions both from competitive and non-competitive conditions. The recovery of the resin was over 65% by H2SO4 and Na2CO3.

Metal ion binding properties of poly(N-vinylimidazole) hydrogels

The ability of poly(N-vinylimidazole) hydrogels to bind Cu(II), Co(II), Ni(II), Zn(II), Cd(II), Pb(II), Hg(II), Na(I) and Ca(II) cations, as well as uranyl, vanadium, rhenium, and molybdenum complexes, was studied by a batch equilibrium procedure using atomic absorption spectroscopy and UV-Vis spectrophotometry. The optimum pH for ion adsorption was determined in any case. The influence of the crosslinking degree of the hydrogel on the sorption kinetics and the sorption capacity at equilibrium were also studied. Sorption from the binary mixture Cu(II) + U(VI) was also analyzed at the optimum pH. Elution of the ions adsorbed from single and binary solutions was achieved in all cases. A selective desorption of loaded hydrogels with two types of ions was attained. The general conclusion is that poly(N-vinylimidazole) hydrogels are excellent materials for retention of all the ions studied here [except for Pb(II), Na(I), and Ca(II)]. The elution, which can be selective, allows regeneration of the hydrogel. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67:1109–1118, 1998

Adsorption and Desorption of Atrazine, Deethylatrazine, Deisopropylatrazine, Hydroxyatrazine, and Metolachlor in Two Soils from Virginia

The objective of this study is to characterize the adsorption-desorption properties of atrazine, deethylatrazine (DEA), deisopropylatrazine (DIA), hydroxyatrazine (HA), and metolachlor in the Emporia (fine loamy, siliceous, thermic Typic Hapludult) and Cullen (clayey, mixed, thermic Typic Hapludult) soils. Adsorption and desorption isotherms were determined using the batch equilibrium procedure. Four solution concentrations (2.5, 7.5, 13.2, and 26.4 µmol L−1) were prepared of each chemical and four 24-h desorption periods at each concentration followed immediately after the adsorption process. Organic carbon distribution coefficients (Koc ranged from 140 to 234 for atrazine, 80 to 110 for DEA, 128 to 130 for DIA, 493 to 609 for HA, and 162 to 190 for metolachlor. For desorption, all chemicals exhibited hysteresis. Hysteresis was quantified: ω = [1/nads ÷ 1/ndes − 1] × 100. Soil type affected the degree of atrazine, DEA, and metolachlor hysteresis (ω), and initial concentration had a significant effect on ω only in the Cullen soil. The amount of chemical desorbed, expressed as the percentage of the amount adsorbed, was about 60% for DEA, 43% for atrazine, 40% for metolachlor, 37% for DIA, and 31 and 17% for HA on the Emporia and Cullen soils, respectively. Soil type and initial concentration had no significant effect on the percentage of chemical desorbed except for HA. The sorption properties for atrazine and metolachlor in these soils are similar. The tendency of HA to leach will be low in these soils compared with atrazine, while the tendency of DEA to leach will be high.

Metal ion sorption ability of poly(4‐vinylpyridine‐co‐N,N‐dimethylacrylamide)

AbstractResins containing amide and 4‐vinylpyridine moieties were synthesized by radical polymerization. All the resins were completely insoluble in water and characterized by FT‐IR spectroscopy, elemental analysis and thermal analyses. The ability to bind Cu(II), Fe(II), Fe(III) and U(VI) ions at different pHs was studied by batch equilibrium procedure. Uranium(VI) was adsorbed at pH 1 above 50% by the resins 1 and 2. The selectivity of uranium(VI) respect to copper(II) at pH 1.0 was 2.11. The uraniumloaded resin 2 could be partially recovered by treatment with H2SO4 and Na2CO3.