Polyethylene-coated Polypropylene Research Articles

Enhancement of carbon dioxide adsorption performances by hydrazinolysis of poly(n-vinylformamide) grafted fibrous adsorbent

Abstract Emission of carbon dioxide (CO2) becomes a main concern in battling issues of global warming. The strategy to reduce the concentration of CO2 could be achieved by implementing carbon capture and storage (CCS) technology such as adsorption by solid adsorbents. In this work, hydrazone containing adsorbent was prepared by radiation induced grafting of N-vinylformamide (NVF) onto polyethylene coated polypropylene (PE/PP) fibrous sheets and subsequent hydrazinolysis for CO2 capture. Hydrazinolysis of the amide group to hydrazone moieties was accelerated by the addition of ammonium salts. These newly prepared adsorbent was characterized by scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR). The adsorption tests of pure CO2 and N2, and their mixture were carried using the gravimetric method. The result revealed that the obtained adsorbent was highly CO2 selective and attained remarkably higher CO2 sorption capacity of 3.1 mmol/g at 30 bar and room temperature compared to 0.3 mmol/g for amide-containing sample. The new adsorbent could be used for few repeated cycles with negligible loss in sorption capacity. Overall, the hydrazone-containing adsorbent has storing potential for CO2 capture, and more studies need to be conducted for further development.

Activation of inert polyethylene/polypropylene nonwoven fiber (NWF) by plasma-initiated grafting and amine functionalization of the grafts for Cu(II), Co(II), Cr(III), Cd(II) and Pb(II) removal

In this study, the emulsion graft polymerization of glycidyl methacrylate (GMA) by environmentally friendly plasma-induced technique onto nonwoven polyethylene-coated polypropylene (NWF) fiber and its functionalization with 4-aminobenzoic acid (PABA) were carried out as a novel adsorbent. The influence of plasma source, irradiation time and reaction parameters were studied by a systematic approach. For the grafting of GMA, the optimal plasma treatment conditions using Ar-plasma were found to be 0.2 mbar plasma pressure, 70-watt plasma power, and 120s plasma exposure time. Grafting reaction conditions onto plasma-treated NWF was 4% GMA concentration, 40 °C graft polymerization temperature, and 4 h grafting time. The PABA modification parameters of GMA-grafted NWF fiber have also been optimized for the first time by several solvents and kinetic studies. Epoxy ring in GMA-g-NWF structures (118 ±12% grafting degree) was opened and its modification with PABA was achieved and 81 ± 3% (2.15 mmol PABA/g polymer) conversion was obtained. The samples were characterized by FTIR, XPS, EDX, SEM, contact angle, and TGA techniques. The Cu(II), Co(II), Cr(III), Cd(II) and Pb(II) removal experiments were carried out by ICP-MS in batch mode as a function of pH, contact time, initial concentration and regeneration. Between pH 2–8 range, NWF fabric adsorbent is effective at pH 5 for heavy metal removal. The maximum adsorption capacities (qmax) were determined from Langmuir isotherm as 35.08 mg Cu(II)/ g adsorbent, 31.15 mg Co(II)/g adsorbent, 34.24 mg Cr(III)/g adsorbent, 51.81 mg Cd(II)/g adsorbent and 63.36 mg Pb(II)/g adsorbent, respectively at an initial feed concentration of 100 ppm, demonstrating the promising potential of the NWF fiber-based adsorbent to steadily and efficiently adsorb these toxic metal ions. The experimental data of heavy metals followed pseudo-second-order kinetic and the Langmuir adsorption models. The adsorbent material could be easily regenerated at least five cycles with a 3% HNO3 solution.

Synergizing radiation-induced emulsion graft polymerization of glycidyl methacrylate on polyethylene-coated polypropylene nonwoven fabric by addition of hydrophobic alcohols

The radiation-induced emulsion graft polymerization method is limited for applying concentrations higher than the monomer concentration that enables stable formation of monomer micelles. Furthermore, foaming may occur because of the presence of the surfactant, which is essential for the formation of micelles, resulting in likely splashing around a highly flammable monomer emulsion. In the present study, to overcome these issues, we investigate the effect of added alcohols on the grafting of glycidyl methacrylate (GMA) in emulsion graft polymerization. By adding hydrophobic alcohols to the GMA monomer emulsion of the given system, we succeeded in increasing polymerization rate at low monomer concentrations and developing a highly safe method of emulsion graft polymerization. By adding 0.5 wt% of hydrophobic alcohol such as 1-octanol to the GMA monomer emulsion, the degree of grafting was 4 times higher than in the case without addition. In addition, we successfully reduced the foamability of the GMA monomer emulsion deriving from the surfactant. This is a novel graft polymerization method with promising wide industrial application, as it brings improvements for the existing issues of the conventional emulsion graft polymerization method — (1) emulsion stability under low concentration monomer and (2) process stability due to foaming of the monomer emulsion during polymerization.

Machine learning approach for prediction of the grafting yield in radiation-induced graft polymerization

Grafting yields for the radiation-induced graft polymerization of a methacrylate ester monomer to give a polyethylene-coated polypropylene nonwoven fabric were predicted as an objective variable by a machine learning approach. The degrees of grafting were obtained from actual experiments. Monomer structure information, atomic charge information, atomic NMR shift information, and infrared absorption wavenumber information, derived from density functional theory calculations, were adopted as explanatory variables of a grafting yield prediction model. Among machine learning algorithms as a prediction model on the grafting yield, XGBoost and random forest models showed higher prediction accuracy, compared to a multiple linear regression model. The prediction accuracies of the various algorithm decreased in the order: XGBoost > random forest > multiple linear regression/LASSO > decision tree > multiple linear regression. The monomer polarizability and the O2 NMR shift were found to be important explanatory variables for predicting the grafting yield in the XGBoost model. This is probably because the polarizability, which represents a miscibility indicator of the monomer to the trunk polymer, and the O2 NMR shift, which represents a diffusivity indicator of the monomer into the trunk polymer, remarkably reflect the difference in the substituent structure of the methacrylate ester monomers.

Reusable fibrous adsorbent prepared via Co-radiation induced graft polymerization for iodine adsorption

Volatile iodine released from nuclear power plant reactors is radiological hazard to environment and human's health because of their high fission yield and environmental mobility. The complexity of nuclear waste management motivated the development of solid-phase adsorbents. Herein, co-radiation induced graft polymerization (CRIGP) was employed in the graft polymerization of N-vinyl-2-pyrrolidone (NVP) onto polyethylene-coated polypropylene skin–core (PE/PP) fibers using electron beam (EB) irradiation. This work provides a one-step green synthetic approach to prepare iodine fibrous adsorbents without any chemical initiators or large amount of organic solvent. The original and modified PE/PP fibers were characterized by fourier transform infrared spectrometry (FTIR), X-ray photoelectron spectroscopy (XPS), thermogravimetric (TG) and scanning electron microscopy (SEM) to demonstrate the grafting of NVP onto the PE/PP fibers. The capacity of iodine absorbed by the PE/PP-g-PNVP fibers was 1237.8 mg/g after 180 min. Meanwhile, absorbents can be regenerated efficiently by two different means of ethanol elution and heating at 120 °C, respectively. Within 10 min, 94.17% and 90.12% of the iodine can be released from the PE/PP-g-PNVP fibers with these two methods, respectively. The adsorbent exhibited a long service life of at least ten adsorption–desorption cycles, suggesting that PE/PP-g-PNVP fibers might be a promising adsorbent for volatile iodine adsorption from fission products in nuclear power plant reactors.

Effect of monoethanolamine concentration on CO2 capture by poly (chloromethyl styrene) grafted fibrous adsorbent

The CO2 adsorption performance of poly (chloromethyl styrene) (PCMS) grafted on polyethylene coated polypropylene (PE/PP) fibrous polymer substrate and followed by amination with monoethanolamine (MEA) was investigated using gravimetric sorption system. The chemical, structural and morphological changes in the aminated adsorbents were evaluated using Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD), respectively. The amination was carried out using three different compositions of MEA (50, 80 and 100%) diluted in water to optimize the yield of loaded amine. The highest percent of amination obtained was about 71% and the amine content increase with the rise in MEA concentration. The CO2 adsorption capacity increase with MEA concentration with the highest capacity recorded was1.63 mmol/g with pure CO2 gas at 30 bars and room temperature.

Synthesis of Fibrous Metal Adsorbent with a Piperazinyl-Dithiocarbamate Group by Radiation-Induced Grafting and Its Performance.

A fibrous grafted metal adsorbent with a piperazinyl-dithiocarbamate (PZ-DTC) group was synthesized by radiation-induced emulsion grafting of glycidyl methacrylate onto a polyethylene-coated polypropylene nonwoven fabric (PE/PP-NF) and subsequent three-step chemical modifications consisting of amination with N-(tert-butoxycarbonyl)piperazine (N-Boc-piperazine, NBPZ), deprotection of the Boc group with HCl, and dithiocarbamation with carbon disulfide (CS2). By using the NBPZ reagent in the amination step, the self-cross-linking of piperazine (PZ) could be completely suppressed, unlike using the PZ reagent. Consequently, the PZ-DTC group density of the fibrous grafted metal adsorbent synthesized through NBPZ attained 2.122 mmol-PZ-DTC/g-adsorbent, which was approximately 6 times higher than that of the metal adsorbent synthesized through PZ. The fibrous grafted metal adsorbent with the PZ-DTC group selectively adsorbed heavy metal ions over light metal ions. Furthermore, it exhibited high adsorption capacity, particularly for Cu2+. The Cu2+ adsorption capacity was determined to be 1.903 mmol-Cu2+/g-adsorbent by a batchwise adsorption test using a single-metal-ion aqueous solution at pH 6. The order of metal ion selectivity of the fibrous grafted metal adsorbent with the PZ-DTC group was Na+ < Mg2+, Ca2+, Co2+, Cd2+ < Pb2+ ≪ Cu2+, and Co2+ ≈ Ni2+ < Zn2+ ≪ Cu2+. In addition, the fibrous grafted metal adsorbent with the PZ-DTC group did not lose its metal adsorption function even under highly alkaline conditions (pH 15). It could recover Cu2+ efficiently and selectively from a high-concentration Na+ aqueous solution at this pH. The Cu2+ adsorption capacity of the fibrous grafted metal adsorbent with the PZ-DTC group was 0.754 mmol-Cu2+/g-adsorbent under a highly alkaline condition, a 10 M NaOH aqueous solution at pH 15. This value was approximately 2.4 times higher than that of the other grafted adsorbent with an amine-type functional group.

Kinetic studies of radiation induced grafting of N-vinylformamide onto polyethylene/polypropylene fibrous sheets and testing its hydrolysed copolymer for CO2 adsorption

Kinetics of the grafting process is highly important for understanding reaction mechanism pertaining graft copolymer preparation quality, reproducibility and economics. In this study, the kinetic behaviour of grafting of N-vinylformamide (NVF) monomer onto polyethylene coated polypropylene (PE/PP) fibrous sheet was investigated with respect to the dependence of degree of grafting (G%) on various reaction parameters like monomer concentration, absorbed dose, and reaction temperature for the first time. The kinetic analysis covered not only the initial polymerisation rate (rp0), radical recombination rate and delay time (t0) but also orders evaluations of the grafting rate dependence on the monomer concentration, absorbed dose and temperature. The chemical and morphological changes caused by the inclusion of poly(NVF) grafts into PE/PP substrates were monitored by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The results of the present study led to the establishment of a quantitative kinetic description for grafting of NVF onto PE/PP and demonstrated that the degree of grafting is strongly dependent on the investigated reaction parameters. The adsorbent containing poly(vinylamine) obtained by the hydrolysis of the grafted poly(NVF) chains showed a remarkable CO2 adsorption capacity of 1.36 mmol/g at room temperature and a pressures of 30 bar.

Preparation of amidoxime-based PE/PP fibers for extraction of uranium from aqueous solution

A novel amidoxime-based fibrous adsorbent, denoted as PE/PP-g-(PAAc-co-PAO), was prepared by pre-irradiation grafting of acrylic acid and acrylonitrile onto polyethylene-coated polypropylene skin–core (PE/PP) fibers using 60Co γ-ray irradiation, followed by amidoximation. The original and modified PE/PP fibers were characterized by a series of characterization methods to demonstrate the attachment of amidoxime groups onto the PE/PP fibers. Breaking strength tests confirmed that the fibrous adsorbent could maintain good mechanical properties. The adsorption capacity of the PE/PP-g-(PAAc-co-PAO) fibers was investigated in simulated seawater with an initial uranium concentration of 330 μg/L. The uranium adsorption capacity was 2.27 mg/g-adsorbent after 24 h in simulated seawater, and the equilibrium data were well described by the Freundlich isotherm model. The PE/PP-g-(PAAc-co-PAO) adsorbent exhibited good regeneration and recyclability during five adsorption–desorption cycles. The adsorption test was also performed in simulated radioactive effluents with uranium concentrations of 10 and 100 μg/L. The effect of the pH value on the adsorption capacity was also studied. At a very low initial concentration 10 μg/L solution, the PE/PP-g-(PAAc-co-PAO) fiber could remove as much as 93.0% of the uranium, and up to 71.2% of the uranium in the simulated radioactive effluent. These results indicated that the PE/PP-g-(PAAc-co-PAO) adsorbent could be used in radioactive effluents over a wide range of pH values. Therefore, the PE/PP-g-(PAAc-co-PAO) fibers, with their high uranium selectivity, good regeneration and recyclability, good mechanical properties, and low cost, are promising adsorbents for extracting uranium from aqueous solutions.

Biodiesel fuel production from waste cooking oil using radiation-grafted fibrous catalysts

Waste cooking oil, which can be used as a raw material for biodiesel fuel (BDF), contains two kinds of oil components: triglycerides (TGs) and free fatty acids (FFAs). Therefore, both alkaline-type and acid-type catalysts are needed to produce BDF from waste cooking oil. In this study, an alkaline-type grafted fibrous catalyst bearing OH- ions was synthesized by radiation-induced emulsion grafting of 4-chloromethylstyrene onto a polyethylene-coated polypropylene (PE/PP) nonwoven fabric, amination with trimethylamine, and further treatment with NaOH. Furthermore, an acid-type catalyst bearing H+ ions was synthesized by radiation-induced emulsion grafting of ethyl p-styrenesulfonate onto a PE/PP nonwoven fabric, saponification with NaOH, and protonation with HNO3. The OH- and H+ densities of the grafted fibrous catalysts were controlled by the grafting yield. The maximum OH- and H+ densities of the catalysts were 3.6mmol-OH-/g-catalyst and 3.4mmol-H+/g-catalyst, respectively. The performances of the catalysts were evaluated in the batchwise transesterification of TGs and ethanol, and the batchwise esterification of FFAs and ethanol. In both cases, TGs and FFAs were gradually converted into BDF. The mixed oil and four actual waste cooking oils, which contained both TGs and FFAs, were completely converted into BDF by sequential catalytic reactions with the acid-type grafted fibrous catalyst and then the alkaline-type grafted fibrous catalyst.

Modification of polyethylene-polypropylene fibers by emulsion and solvent radiation grafting systems for boron removal

Preparation of boron-selective adsorbent was carried out by radiation induced grafting of glycidyl methacrylate (GMA) onto polyethylene-coated polypropylene (PE-PP) nonwoven fabric in emulsion or solvent medium followed by immobilization of N-methyl-D-glucamine (NMDG). Adsorbent precursors with 180 % degree of grafting (DG) were obtained by applying reaction parameters comprising 20 kGy dose, 5 % monomer concentration and 1 h reaction time in emulsion compared to 30 kGy, 10 % and 3 h in solvent medium. A glucamine density of 2.2 mmol/g could be imparted to the obtained adsorbents. The emulsion-mediated grafting was found more efficient and economical for preparation of boron chelating adsorbents.

Radiation induced emulsion graft polymerization of 4-vinylpyridine onto PE/PP nonwoven fabric for As(V) adsorption

A novel nonwoven fabric adsorbent having 4-vinylpyridine functional groups was prepared by using radiation-induced emulsion graft polymerization method and grafting 4-vinylpyridine monomer onto a polyethylene-coated polypropylene nonwoven fabric (NWF) in aqueous emulsion solution. The grafting conditions of the 4-vinylpyridine monomer onto the NWF were optimised and 150% Dg VP-g-NWF was prepared using 30 kGy pre-irradiation dose, 5% VP monomer concentration and 0.5% (w/w) Tween 20 in aqueous emulsion. Grafted 4-vinylpyridine chains on the NWF were then quaternized for the preparation of QVP-g-NWF adsorbent. All fabric structures were characterized by using Fourier-transform infrared spectrometer, x-ray photoelectron spectrometer and scanning electron microscope. QVP-g-NWF adsorbent was used in batch adsorption experiments for As(V) ions by studying the pH, contact time, and initial As(V) ion concentration parameters. Results showed that QVP-g-NWF adsorbent has significant As(V) adsorption and experimental As(V) adsorption capacity was 98.04mg As(V)/g polymer from 500mg/L initial As(V) concentration at pH 7.00.

New CO2 adsorbent containing aminated poly(glycidyl methacrylate) grafted onto irradiated PE-PP nonwoven sheet

A new CO2 adsorbent containing triethylamine (TEA) was prepared by radiation induced grafting of glycidyl methacrylate (GMA) onto polyethylene coated polypropylene (PE-PP) non-woven sheet followed by amination reaction. The degree of grafting (DOG%) was controlled by variation of monomer concentration and absorbed dose. The incorporation of aminated poly(GMA) was investigated by Fourier transform infrared (FTIR) and scanning electron microscope (SEM). The adsorbent with DOG of 350% and amination yield of 60% exhibited CO2 adsorption capacity of 4.52mol/kg at ambient temperature and pressure.

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.

Polyolefin fibers with chemically fixed active ester for the solid phase synthesis of an amide derivative

Reactive fibers having chemically fixed active ester were derived from chloromethylstyrene grafted polyethylene-coated polypropylene staple fiber and non-woven cloth. First, chlorine atoms in each fiber were substituted by mercapto groups, and the resulting fibers were reacted with N-hydroxymaleimide to obtain fibers containing chemically fixed N-hydroxysuccinimide moieties. These fibers were converted into reactive fibers having chemically fixed active ester by reaction with a model carboxylic acid (3-(2-bromophenyl)propionic acid) in the presence of a condensing reagent (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride) in excess. Performances of both reactive fibers in the model amide synthesis were compared by their reaction with 2-phenylethylamine. Although the reactive non-woven cloth gave an amide contaminated with unknown organic impurities, the reactive staple fiber yielded highly pure product. Possible causes of this difference are discussed on the basis of SEM observation of both fibers.

Preparation of Graft Adsorbent Having Amine Groups and Its Au(III) Adsorption Performance

Metal adsorbent was prepared by co-graft polymerization of allylamine and methacrylic acid (or N-vinylacetamide) onto nonwoven fabrics made of polyethylene-coated polypropylene fiber using radiation induced graft polymerization method. Behavior of the resulting adsorbents in uptake of Au (III) was evaluated by both batch and columnar methods. In the column test, the breakthrough of Au (III) was evaluated with three different flow rates of 260, 520 and 1040 h-1 in space velocity (SV) by pumping 1mM Au (III) solution into the column at pH 3. Breakthrough points of three flow rates were 163, 150 and 144 bed volumes (BV), respectively. Furthermore, the breakthrough of Au (III) was evaluated at pH range from 1 to 7 by pumping 100 ppb Au (III) solution into the column in the SV of 4680 h-1. The breakthrough point was 175 BV at the pH 1 and 2, and went up to 179 BV at pH 3.

Use of radiation grafting of polyethylene‐coated polypropylene nonwoven fabric by acrylamide for the removal of heavy metal ions from wastewaters

AbstractThe graft copolymerization of acrylamide (AAm) monomer onto polyethylene‐coated polypropylene (PE‐co‐PP) nonwoven fabric was carried out by the mutual irradiation method. The general peculiarities of the grafting have been studied by gravimetric, scanning electron microscope (SEM), mechanical properties, and Fourier transform infrared (FTIR) methods. The influence of absorbed dose, dose rate, as well as the monomer concentration on the degree of grafting has been determined. Metal ions uptake of Cu2+, Co2+, Ni2+ by the grafted fabrics was evaluated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3240–3245, 2006

Radiation Grafting of 2-Hydroxy Ethyl Methacrylate (HEMA)/Glycidyl Methacrylate (GMA) onto Polyethylene-Coated Polypropylene Non-woven Fabric

The paper presents results of an investigation of the possibility of applying polyethylene-coated polypropylene (PE-co-PP) nonwoven fabric for treating dye wastes resulting from wastewater of the textile industry. For this purpose the radiation-induced graft copolymerization of binary mixtures of 2-hydroxy ethyl methacrylate (HEMA)/glycidyl methacrylate (GMA) onto polyethylene-coated polypropylene by the pre-irradiation method has been investigated. The effect of different factors that may affect the grafting percent such as solvent type and comonomer compositions were studied. Two solvents, dimethyl sulphoxide (DMSO) and 1-butanol were used. It was found that the degree of grafting depend upon the type of solvent and the composition of the comonomer mixture. Morphology of grafted nonwoven fabric was examined by scanning electron microscope (SEM). The hydrophilic properties in terms of swelling percent and water uptake were investigated. The higher swelling and water uptake percent were achieved at 100% HEMA diluted with 1-butanol. The use of these modified samples as absorbents for different classes of dyestuffs normally released from textile factories was achieved. The results obtained showed that the highest percentage of dye sorption was found in the case of basic dye and the lowest one in the case of reactive dye, depending on the reactive groups on the dye. Copolymers with a higher proportion of HEMA monomer diluted with 1-butanol as solvent showed the highest hydrophilic properties and higher dye uptake.

Rapid removal of arsenic(V) by zirconium(IV) loaded phosphoric chelate adsorbent synthesized by radiation induced graft polymerization

Fibrous arsenic(As) adsorbent was synthesized by loading zirconium(Zr) on fibrous phosphoric adsorbent which was directly synthesized by radiation-induced grafting of 2-hydroxyethyl methacrylate phosphoric acid on polyethylene-coated polypropylene nonwoven fabric. Zirconium reacted with phosphoric acid grafted in the polyethylene layer. Zirconium density of the resulting adsorbent was 4.1 mmol/g. The breakthrough curve of As(V) adsorption was independent of the flow rate up to 1300 h −1 in space velocity. The total capacity of As(V) was 2.0 mmol/g-adsorbent at pH of 2. The adsorbed Zr(IV) could be evaluated by 0.4 M sodium hydroxide solution because no Zr(IV) could be found in the eluted solution. Anions of chloride and nitrate interfered the breakthrough capacity.

Fibrous Iminodiacetic Acid Chelating Cation Exchangers with a Rapid Adsorption Rate

Fibrous chelating cation exchangers were derived from chloromethylstyrene-grafted polyethylene-coated polypropylene filamentary fiber and its nonwoven cloth. Ligand contents and acid capacities of the resulting chelating filamentary fiber (FIDA-f) and cloth (FIDA-c) were ca. 2 mmol/g and ca. 4 mequiv/g, respectively. A distribution study by using FIDA-c clarified that the selectivity sequence of divalent metal ions is Mg(II) ∼ Ca(II) < Co(II) ∼ Zn(II) < Cd(II) ∼ Ni(II) < Pb(II) < Cu(II). Capacities of FIDA-c in mmol/g at around pH 5 were as follows: for divalent ions, Ca(II) = 0.91, Mg(II) = 0.98, Cd(II) = 1.5, Ni(II) = 1.5, Pb(II) = 1.6, and Cu(II) = 1.8; for trivalent ions, La(III) = 0.75, Gd(III) = 0.92, and Lu(III) = 1.0. A column-mode study using a FIDA-f packed column revealed that breakthrough capacities for Cu(II) (ca. 1 mmol/g) were not dependent on flow rates up to 200−300 h-1 in space velocity but slightly decreased with a further increase in the flow rate. Conditioning-adsorption-elution oper...