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).     

Aerosol Retention in the Vicinity of a Breach in a Tube Bundle: An Experimental Investigation

This article summarizes the main results of a bench-scale program focused on experimentally assessing the aerosol retention near the tube breach in a tube bundle. The major variables investigated were particle nature (polydispersed TiO ₂ agglomerates vs. solid, monodisperse SiO ₂ spheres) and Re _D (0.8?2.7· 10 ⁵ ). In addition, comparisons to other data sets provided insights into the particle aerodynamic size effect on retention efficiency. Results showed that particle nature substantially affects aerosol retention in the tube bundle: mass retention efficiency was low for TiO ₂ agglomerates (less than 30%) whereas it was much higher for SiO ₂ particles (around 85%). Retention efficiency is also affected by Re _D : its sensitivity was found to follow a log-normal behavior with a maximum retention attained at Re _D near 1· 10 ⁵ . This evolution with Re _D was similar for both types of compounds. Particle size also influences retention efficiency: the bigger the TiO₂ agglomerates the lower retention efficiency (no data were available for SiO ₂ ). Among all these variables, particle nature was noted to have a prime importance for in-bundle retention, whereas Re _D and particle aerodynamic size, although also affect retention efficiency, did not play such a key role. In light of the results, the presence of retention-inhibiting mechanisms such as fragmentation, resuspension or bouncing has been discussed. The data recorded will enhance the overall understanding of the governing mechanisms involved and will serve as a database against which compare model predictions. Nevertheless, further experimental data would be desirable to set up a sound database.     

Retention and Release of Lead by a Very Fine Sandy Loam. I. Isotherm Modeling

Abstract

The retention of lead by a very fine sandy loam was investigated. Aqueous lead concentrations between 10 and 1000 mg/L and soil concentrations ranging from 10 to 167 g/L were used. Lead retention by the soil was a strong function of pH. The width of the pH—adsorption edge decreased with increasing lead concentration. Experimental results were modeled using the Langmuir, Freundlich, and BET isotherms. Only the Langmuir and Freundlich isotherms successfully represented the experimental results. The role of surface precipitation was assumed to be small because of the failure of the BET isotherm to adequately predict metal retention. The Freundlich isotherm provided the best fit because a maximum surface concentration was usually not observed. Langmuir and Freundlich isotherms parameters varied in a way that suggested that the average binding energy and the distribution of bond strengths increased with increasing pH. The isotherm expressions determined in this study can be used as source-sink terms in the generalized mass transport model.     

BOOK REVIEW

ABSTRACT

A previous paper reported the effect of increasing concentrations of hydrofluoric, oxalic, sulfuric and phosphoric acids at three fixed HCl or HNO₃ concentrations on the retention of Am(III), Th(IV) or Np(IV), and U(VI) by the new chelating ion-exchange resin Diphonix?. In this paper the metal uptake data have been analyzed by calculating the effect that complex formation in solution has on the overall metal uptake by the resin. The calculations performed have allowed us to conclude that in most cases the uptake of Am(III) and U(VI) by Diphonix can be explained by assuming that only the uncomplexed metal cation is sorbed. With tetravalent actinides, on the contrary, the uptake data can only be explained if the simultaneous sorption of the uncomplexed cation and of neutral metal complexes is assumed. Indirect evidence has also been obtained on the existence of anionic fluoride complexes of Np(IV). In all other cases, with minor exceptions, the complex formation data available in the literature seem to describe accurately the behavior of the investigated systems.     

The Role of Hydroxamic Acids in the Retention of Fission Products in TBP Diluents. A Quantitative Study in a Model System

Abstract

The degradation with nitric acid of kerosene-type diluents of TBP in the reprocessing of nuclear fuel leads to the formation of primary nitroalkanes. These, under acid conditions, may hydrolyze to hydroxamic acids, HA, which are well-known complex-ing agents of many metal ions, including ⁹⁵Zr. The formation of very stable HA-⁹⁵Zr complexes has been proposed as a rationale for the retention of ⁹⁵Zr in the diluents. However, the results of this study carried out in a model system, the acid-catalyzed conversion of 1-nitropropane to propanhydroxamic acid, and the subsequent hydrolysis to carboxylic acid and hydroxylamine—easily extensible to the actual reprocessing processes—indicate that in these systems the equilibrium concentration of hydroxamic acids attainable is too low (10^?8 to 10^?9 M) to account for the “zirconium retention” phenomenon.     

A New Centrifugal Ultrafiltration Device

Abstract

A novel ultrafiltration device is described. It consists of a vertical dialysis cell in which the semipermeable membrane is supported by a metal or plastic porous, rigid sheet. The dialysis cell is mounted in a centrifuge swinging bucket, or rotor hole, with the membrane parallel to the centrifuge radius. Experiments are performed by filling one dialysis cell compartment with the liquid sample to be treated and by spinning it in a centrifuge. Effluent is collected from the other (initially empty) compartment of the dialysis cell. Membranes used in these cells have similar permeabilities but better retention than those used in unstirred ultrafiltration cells for small filtrate volumes.     

New polymeric structures designed for the removal of Cu(II) ions from aqueous solutions

New polymeric structures obtained by chemical transformations of maleic anhydride/dicyclopentadiene copolymer with triethylenetetraamine, p‐aminobenzoic acid, and p‐aminophenylacetic acid were used for the removal Cu(II) ions from aqueous solutions. The experimental values prove the importance of the chelator nature and of the macromolecular chain geometry for the retention efficiency. The retention efficiency (η_r), the retention capacity (Q _e ), and the distribution coefficient of the metal ion into the polymer matrix (K _d ) are realized by evaluation of residual Cu(II) ions in the effluent waters, by atomic adsorption. Also are discussed the influence of pH, the thermal stability of the polymer, and their polymer–metal complex, as well as the particular aspects regarding the contact procedure and the batch time. Based on the polymers and polymer–metal complexes characterization a potential retention mechanism is proposed. All polymer supports as well theirs metal–complexes are characterized by ATD and FTIR measurements. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1397–1405, 2007     

Chelating water-soluble polymers associated with ultrafiltration membranes for metal ion removal

This article describes the retention properties of commercial chelating water-soluble polymers, for different metal ions in aqueous solution using a liquid-phase polymer-based retention (LPR) technique. The polymers studied were poly(ethyleneimine) or P(EI) (water-free and a 50?% aqueous solution) and poly(ethyleneimine epichlorohydrin) or P(EIE) (a 17?% aqueous solution). These commercial polymers were fractionated by ultrafiltration membranes and then characterized by Fourier-transformed infrared spectroscopy. The extraction process was performed using the following metal ions: Cu²⁺, Cd²⁺, Co²⁺, Ni²⁺, Zn²⁺, Pb²⁺ and Cr³⁺. In the washing studies, we varied the pH (3, 5 and 7) and retention time. The results showed that P(EI) showed high retention for all the metal ions at pH 7 and for selective retention of Cu²⁺ at pH 5, while P(EIE) showed selective retention of Cu²⁺ ions at pH 7. Using the enrichment method, the maximum retention capacity of Cu²⁺ and Cd²⁺ was achieved using a 50?% aqueous solution of P(EI) at pH 5 and 7, respectively. Finally, charge–discharge experiments for Cu²⁺ were analysed by changing the pH from basic to acidic over three cycles. These results showed that it is possible to remove metal ions and regenerate the removal capacity of the polychelatogens using the LPR technique.     

Programmed Exclusion Chromatography: A Method for the Continuous Control of Retention

Abstract

Means are proposed for controlling retention and thus for instituting retention programming in exclusion chromatography. Control is to be gained by the addition of a high molecular weight polymer to the incoming solvent. Preliminary data confirm that such a polymer strongly affects retention.     

Polymer-Enhanced Crossflow Filtration for Removal of Fe(III), Cu(II), and Cd(II) Ions from Dilute Aqueous Solutions

Abstract

The removal of Fe(III), Cu(II), and Cd(II) ions from aqueous solutions was studied by polymer-enhanced crossflow filtration technique. Alginic acid polymer was used as complexing agents to enhance the retention. Alginic acid/cellulose composite membranes were used in the filtration. In the filtration of metal ion solutions the effects of alginic acid content of the membranes and pH on the percent retention and the permeate flux were examined. The maximum percent retention was found as 98% for 1 × 10^?4 M Fe(III) solution at the flow velocity of 100 mL/min, pH of 3.0, pressure of 60 kPa in the presence of alginic acid as complexing agent by using 0.25 (w/v)% alginic acid/cellulose composite membranes. For 1 × 10^?4 M Cu(II) and Cd(II) solutions the maximum percent retentions were found as 71% and 80% respectively using 0.50 (w/v)% Alginic acid/cellulose composite membranes when the filtration was carried out in the presence of alginic acid at pressure of 10 kPa, flow velocity of 100 mL/min and pH of 7.0.     

Preparation,characterization, and metal ion retention capacity of Co(II) and Ni(II) from poly(p‐HO‐ and p‐Cl‐phenylmaleimide‐co‐2‐hydroxypropylmethacrylate) using the ultra filtration technique

p‐Chlorophenylmaleimide and p‐hydroxyphenylmaleimide with 2‐hydroxypropyl methacrylate were synthesized by radical polymerization, and the metal ion retention capacity and thermal behavior of the copolymers were evaluated. The copolymers were obtained by solution radical polymerization with a 0.50 : 0.50 feed monomer ratio. The maximum retention capacity (MRC) for the removal of two metal ions, Co(II) and Ni(II) in aqueous phase were determined using the liquid‐phase polymer based retention technique. Inorganic ion interactions with the hydrophilic polymer were determined as a function of pH. The metal ion retention capacity does not depend strongly on the pH. Metal ion retention increased with an increase of pH for a copolymer composition 0.50 : 0.50. At different pH, the MRC of the poly(p‐chlorophenylmaleimide‐co‐2‐hydroxypropylmethacrylate) for Co(II) and Ni(II) ions varied from 44.1 to 48.6 mg/g and from 41.5 mg/g to 46.0 mg/g, respectively; while the MRC of poly(p‐hydroxyphenylmaleimide‐co‐2‐hydroxypropyl methacrylate) for Co(II) and Ni(II) ions varied from 28.4 to 35.6 mg/g and from 27.2 to 30.8 mg/g, respectively. The copolymers and copolymer–metal complexes were characterized by elemental analysis, FT‐IR, ¹H NMR spectroscopy, and thermal behavior. The thermal behavior of the copolymer and polymer–metal complexes were studied using differential scanning calorimetry and thermogravimetry techniques under nitrogen atmosphere. The thermal decomposition temperature and T_g were influenced by the binding‐metal ion on the copolymer. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Poly(N‐vinylpyrrolidone‐co‐2‐acrylamido‐2‐methylpropanesulfonate sodium): Synthesis,characterization, and its potential application for the removal of metal ions from aqueous solution

In the current study, poly(N‐vinylpyrrolidone‐co‐2‐acrylamido‐2‐methylpropanesulfonate sodium), poly(VP‐co‐AMPS), was prepared and used for the removal of Cu²⁺, Cd²⁺, and Ni²⁺ ions via a polymer‐enhanced ultrafiltration (PEUF) technique. The copolymer was synthesized by radical polymerization in an aqueous medium with a comonomer feed composition of 50:50 mol %. The molecular structure of the copolymer was elucidated by ATR‐FTIR and ¹H NMR spectroscopy, and the average molecular weight was obtained by GPC. The copolymer composition was determined to be 0.42 for VP and 0.58 for AMPS by ¹H NMR spectroscopy. The copolymer and homopolymers exhibited different retention properties for the metal ions. PAMPS exhibited a high retention capacity for all of the metal ions at both pH values studied. PVP exhibited selectivity for nickel ions. Poly(VP‐co‐AMPS) exhibited a lower retention capacity compared to PAMPS. However, for poly(VP‐co‐AMPS), selectivity for nickel ions was observed, and the retention of copper and cadmium ions increased compared to PVP. The homopolymer mixture containing PAMPS and PVP was inefficient for the retention of the studied metal ions. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41272.     

Evaluation of Selective Sorbents for the Extraction of Valuable Metal Ions (Cs,Rb, Li,U) from Reverse Osmosis Rejected Brine

Abstract

Three commercially available sorbents/exchangers (namely CsTreat, ZrP, and S910) were evaluated under column conditions for the extraction of four metals (Cs(I), Rb(I), Li(I), and U(VI)) from a brine rejected by a Seawater Reverse Osmosis plant. From the obtained breakthrough curves and periodic analysis of the influent and effluent, the uptake capacities of the materials were quantified. The fixation of the target metal onto the sorbents was investigated also by SEM-EDX and FTIR-ATR analysis. The results showed that CsTreat displayed a high sorption capacity of Rb(I) and a fairly high sorption capacity of Cs(I), as the resin S910 showed of U(VI), while ZrP proved to be ineffective for the retention of Li(I).     

Synthesis,crystal structures and studies on Hg2+ sensing by the diazo derivatives of sulfathiazole and sulfamethoxazole

Diazocoupling of sulfathiazole and sulfamethoxazole with 2,4-pentanedione led to the syntheses of compounds R1 and R2. These were fully characterized by single crystal X-ray diffraction studies in conjunction with UV–visible, IR, ¹H NMR, and mass spectral studies. Both the compounds were further screened for their possible use in metal ion recognition. Interestingly, compound R1 showed a selective naked-eye response for Hg²⁺, while R2 did not give a color change for any metal ions. These results can be understood in terms of a solvent-assisted low-energy absorption band in R1 that disappeared upon interaction with Hg²⁺. This absorption band was not observed in the case of compound R2 that consequently failed to show any naked-eye color change in the presence of metal ions.     

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.     

Volatiles Retention in the Drying of Skin Forming Materials PART 3: Heat-Sensitive Materials

ABSTRACT

Ethanol retention in solutions was determined by drying single droplets in a horizontal wind tunnel, with gelatine (Bloom numbers 60 and 150) and gum arabic as encapaulants. The variation in ethanol content, droplet temperature history and crust structure were evaluated in each case. General conclusions are provided for parameters determining volatile- retention in convective drying.     

A NOVEL STRONTIUM-SELECTIVE EXTRACTION CHROMATOGRAPHIC RESIN*

ABSTRACT

The effect of nitric acid concentration on the selectivity of a novel extraction chromatographic resin consisting of an octanol solution of 4,4′(5′)-bis(t-butyl-cyclohexano)-18-crown-6 sorbed on an inert polymeric support for strontium over a number of alkali, alkaline earth, and other metal cations was evaluated. The effect of macro quantities of selected elements on strontium retention by the resin was also examined. The resin is shown to exhibit excellent selectivity for strontium over nearly all of the test elements; only lead and tetravalent neptunium, polonium, and plutonium show significant affinity for the material. In addition, concentrations of calcium or sodium ion up to ～ 0.1 M. are shown not to diminish the sorption of strontium appreciably. Several useful radiochemical separation schemes devised on the basis of the results obtained are described.     

Determination of Surface Areas of Active Carbons by Retention of Ethylene Glycol and Ethylene Glycol Monoethyl Ether

Abstract

Experiments of ethylene glycol and ethylene glycol monoethyl ether retention on some active carbons were carried out to measure the surface areas of the carbons. Some differences were observed between nitrogen-specific surface area values and those obtained from ethylene glycol retention. However, since the differences decreased through an increase of surface oxygen content as a result of treatment of the carbons with H₂O₂, it was evident that ethylene glycol retention depended upon the surface oxygen content. Also, the surface area values obtained from retention of ethylene glycol monoethyl ether did not depend upon the surface oxygen content. Measurements of the ethylene glycol monoethyl ether retention process could be performed in a shorter time than the equivalent ethylene glycol retention measurements.     

Synthesis,metal ion complexation and antibacterial activities of some thiapodands with lipophilic amide and ester end groups

A series of acyclic analogues of thiacrown ethers (podands) 7–12 with lipophilic amide and ester end groups were synthesized in high yield and in a simple way. Their transition metal ions complexation was studied using a conductometric method in acetonitrile at 25°C. Podands 7 and 11 showed a continuous decrease in the molar conductances in their complexation with Ag⁺, Cu²⁺, Cd²⁺, Hg²⁺, Zn²⁺ and Pb²⁺ which begins to level off at a mole ratio of 1:1 podand to metal indicating the formation of a stable 1:1 complexes. On the other hand, podand 9 also showed the formation of 1:1 complexes with above metal cations except with Hg²⁺ ion, which formed a 1:2 podand-to-metal ratio complex. An influence of end groups on metal ion selectivity is evident. Podands having ethoxy end groups (podands 8, 10 and 12 exhibit pronounced metal ion selectivity over podands having amino end groups (podands 7, 9 and 11). Compounds 10 and 12 with dithiaethylene units and ethoxy end groups provide the best selectivity for Hg²⁺ and Ag⁺ ions. These results suggest that podands 10 and 12 could be useful for the selective removal of Hg²⁺ and Ag⁺ ions from industrial waste that may contain a variety of toxic heavy and transition metal ions. The in vitro antibacterial activity of the investigated compounds was tested against several microorganisms such as Bacillus subtilis (ATCC 6633), Micrococcus luteus (ATCC 10240), Staphylococcus aureus (ATCC 43300), Escherichia coli (ATCC 25922) and Enterobacter aerogenes (ATCC 13048). The antibacterial activity of podand 10 is significant for M. luteus and B. subtilis compared with other podands under investigation.     

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