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1.
The individual and competitive adsorption capacities of Pb 2+, Cu 2+ and Cd 2+ by nitric acid treated multiwalled carbon nanotubes (CNTs) were studied. The maximum sorption capacities calculated by applying the Langmuir equation to single ion adsorption isotherms were 97.08 mg/g for Pb 2+, 24.49 mg/g for Cu 2+ and 10.86 mg/g for Cd 2+ at an equilibrium concentration of 10 mg/l. The competitive adsorption studies showed that the affinity order of three metal ions adsorbed by CNTs is Pb 2+>Cu 2+>Cd 2+. The Langmuir adsorption model can represent experimental data of Pb 2+ and Cu 2+ well, but does not provide a good fit for Cd 2+ adsorption data. The effects of solution pH, ionic strength and CNT dosage on the competitive adsorption of Pb 2+, Cu 2+ and Cd 2+ ions were investigated. The comparison of CNTs with other adsorbents suggests that CNTs have great potential applications in environmental protection regardless of their higher cost at present. 相似文献
2.
A viscose rayon succinate (VRS) was studied as a chelating fiber for the removal of metal ions from an aqueous solution. VRS was synthesized successfully from viscose rayon (VR) and succinic anhydride in the presence of dimethylsulfoxide (DMSO), and was characterized by C 13 nuclear magnetic resonance 13C NMR, scanning electron microscopy (SEM), and Fourier transform infrared (FT-IR) analysis. The maximum bivalent metal ion adsorption capacity of the VRS was 6.2 meq/g. Studies on the adsorption behaviour of VRS and its ability to remove bivalent trace metals such as Cu 2+, Zn 2+, Pb 2+, and Ni 2+ from an aqueous solution were performed both by FT-IR and quantitative analyses at different pHs. The results showed that the adsorption of metals on VRS increased as pH increased, and furthermore, that the adsorption capacity of metal ions could be classified as Cu 2+ > Zn 2+ > Ni 2+ > Pb 2+. The adsorption modeling for the interpretation of empirical data was carried out by assuming a probability factor, P( A), and a degree of protonation, χ. Surface potential, Ψ0, and an effective ratio of surface equilibrium constants, Keffect, were obtained using the model. 相似文献
3.
Experimental studies on the retention of cadmium (Cd 2+), copper (Cu 2+), nickel (Ni 2+), and lead (Pb 2+) by bentonite samples from Iran were conducted using single- and multiple-component solutions. Based on the sorption capacity of bentonite the following order was obtained for single- and multiple-component solutions: Pb 2+ > Cd 2+ > Ni 2+ > Cu 2+. The maximum adsorption capacities of bentonite with metals in single- and multiple-component solutions were 29.5%, 22.5%, 19.2%, and 17.1% and 13.5%, 13.4%, 12.1%, and 9.1% for Pb 2+, Cd 2+, Ni 2+, and Cu 2+, respectively. Desorption isotherms of Cd 2+, Cu 2+, Ni 2+, and Pb 2+ deviated significantly from the sorption isotherms, thereby indicating irreversible or very slowly reversible sorption. Finally, soil solution saturation indices and metal speciation were assessed using the Visual MINTEQ 2.6 program and the probability of mineral precipitation was supported by scanning electron microscopy. 相似文献
4.
Hydrotalcite-like compound [Zn 2Al(OH) 6] 2edta· nH 2O(ZnAl-edta) was obtained from the precursor [Zn 2Al(OH) 6]NO 3· nH 2O (ZnAl-NO 3), by the anion exchange method, with the aim of uptake Cu 2+, Cd 2+ and Pb 2+ from the aqueous solutions by chelating process between edta and metal cations. The amount of Cu 2+, Cd 2+ and Pb 2+ adsorbed was monitorized by atomic absorption technique at different contact time, pH and metal concentrations. The results indicate the very fast adsorption of the metal cations by ZnAl-edta reaching the equilibrium of the uptake reaction in two hours for Cu and Pb and 24 h for Cd. The shape of the adsorption isotherms suggests specific interaction and high host– guest affinity. At pH 5.5 and initial concentration Ci = 10 mM, the amount adsorbed was Cs = 1117, 375 and 871 μmol/g for Cu 2+, Cd 2+ and Pb 2+, respectively. 相似文献
5.
This study investigated the removal of Cd 2+, Cu 2+, Ni 2+, and Pb 2+ from aqueous solutions using nanoparticle sorbents (TiO 2, MgO, and Al 2O 3) with a range of experimental approaches. The maximum uptake values (sum of four metals) with multiple component solutions were 594.9, 114.6, and 49.4 mg g ?1, for MgO, Al 2O 3, and TiO 2, respectively. The sorption equilibrium isotherms were described using the Freundlich and Langmuir models. The best interpretation for experiment data was given by the Freundlich model for Cd 2+, Cu 2+, and Ni 2+ in single- and multiple-component solutions. A first-order kinetic model adequately described the experimental data using MgO, Al 2O 3, and TiO 2. SEM-EDX both before and after metal sorption and soil solution saturation indices (SI) in MgO nanoparticles indicated that the main sorption mechanism for heavy metals was attributable to adsorption and precipitation, whereas heavy metal sorption by TiO 2 and Al 2O 3 adsorbents was due to adsorption. These nanoparticles may potentially be used as efficient sorbents for heavy metal removal from aqueous solutions. MgO nanoparticles were the most promising sorbents because of their high metal uptake. 相似文献
6.
The aim of this study was to investigate the heavy metal adsorption performance of supermacroporous poly(hydroxyethyl methacrylate) [PHEMA] cryogel. The PHEMA cryogel was produced by cryo‐polymerization. The PHEMA cryogel was characterized by scanning electron microscopy (SEM). The PHEMA cryogel containing 385 μmol Reactive Green HE‐4BD/g were used in the adsorption studies. Adsorption capacity of the PHEMA cryogel for the metal ions, i.e., Cu 2+, Cd 2+, and Pb 2+ were investigated in aqueous media containing different amounts of the ions (5–600 mg/L) and at different pH values (3.2–6.9). The maximum adsorption capacities of the PHEMA cryogel were 11.6 mg/g (56 μmol/g) for Pb 2+, 24.5 mg/g (385 μmol/g) for Cu 2+ and 29.1 mg/g (256 μmol/g) for Cd 2+. The competitive adsorption capacities were 10.9 mg/g (52 μmol/g) for Pb 2+, 22.1 mg/g for Cd 2+ (196 μmol/g) and 23.2 mg/g (365 μmol/g) for Cu 2+. The PHEMA/Reactive Green HE‐4BD cryogel exhibited the following metal ion affinity sequence on molar basis: Cu 2+ > Cd 2+ > Pb 2+. The PHEMA/Reactive Green HE‐4BD cryogel can be easily regenerated by 50 m M EDTA with higher effectiveness. These features make the PHEMA/Reactive Green HE‐4BD cryogel a potential adsorbent for heavy metal removal. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
7.
Cation-exchange adsorbents were prepared by radiation-induced grafting of glycidyl methacrylate (GMA) onto polypropylene (PP)
fabric and polyethylene (PE) hollow fiber and subsequent phosphonation of epoxy groups of poly(GMA) graft chains. The adsorption
characteristics of Pb 2+, Cu 2+ and Co 2+ for the two cation-exchange adsorbents were studied. In the grafting of GMA onto PP fabric, the degree of grafting (%) increased
with an increase in reaction time, reaction temperature, and pre-irradiation dose. The maximum grafting yield was observed
around 60% GMA concentration. In 50, 130 and 250% GMA-grafted PP fabric, the content of phosphoric acid was 1.52, 3.40 and
4.50 mmol/g at 80 °C in the 85 % phosphoric acid aqueous solution for 24 h, respectively. The adsorption of Pb 2+, Cu 2+ and Co 2+ by PP fabric adsorbent was enhanced with an increased phosphoric acid content The order of adsorption capacity of the PP
fabric adsorbent was Pb 2+>Co 2+>Cu 2+. In adsorption of Pb 2+, Cu 2+ and Co 2+ by PE hollow fiber, the amount of Pb 2+ adsorbed by the PE hollow fiber adsorbent containing 1.21 mmol/g of -PO 3H was ca. 54.4 g per kg. The adsorption amount of Cu 2+ and Co 2+ in the same PE hollow fiber was ca. 21.0 g per kg and ca. 32.1 g per kg, respectively. The order of adsorption of the PE hollow fiber adsorbent was Pb 2+>Co 2+>Cu 2+. 相似文献
8.
In this paper, Methacrylic acid (MAA) and 4-vinyl pyridine (4-VP) as functional monomers, Ethylene glycol two methyl acrylate (EGDMA) as crosslinking agent, isopropyl alcohol as the solvent, prepared the Cu(II)- and Pb(II)- imprinted polymers (IIPs) submicron spheres by precipitation polymerization. The presence/absence of the template ion in the preparation of the imprinted polymer was confirmed by EDX spectroscopy, and the structure of the particles was investigated using IR, SEM and BET analysis. From different components of crosslinker/monomer (C/M) ratio analysis, C/M at 1:3 was the optimal ratio for preparing IIPs. Atomic absorption spectroscopy (AAS) was characterized the imprinted polymers absorption behavior. The results show that the maximum adsorption capacity of Cu2+ and Pb2+ -imprinted polymer were 26.9 mg g?1 and 25.3 mg g?1, respectively. They also have good adsorption capacity and superior selectivity property for Cu2+ and Pb2+ in water, respectively. The selectivity factors (α) for Ni2+, Zn2+, Co2+ and Fe2+ were 16.5 (Cu2+) and 12.1 (Pb2+), 13.8 (Cu2+) and 16.2 (Pb2+), 10.8 (Cu2+) and 10.1 (Pb2+), 20.4 (Cu2+) and 20.7 (Pb2+), respectively. The regeneration experiment result demonstrates an excellent re-utilization property of these two type IIPs, after ten uses, the adsorption capacity can maintain above 60%. 相似文献
9.
Abstract The present study reports the potential of mango peel waste (MPW) as an adsorbent material to remove Cu 2+, Ni 2+, and Zn 2+ from constituted metal solutions and genuine electroplating industry wastewater. Heavy metal ions were noted to be efficiently removed from the constituted solution with the selectivity order of Cu 2+ > Ni 2+ > Zn 2+. The adsorption process was pH-dependent, while the maximum adsorption was observed to occur at pH 5 to 6. Adsorption was fast as the equilibrium was established within 60 min. Maximum adsorption of the heavy metal ions at equilibrium was 46.09, 39.75, and 28.21 mg g for Cu 2+, Ni 2+, and Zn 2+, respectively. Adsorption data of all the three metals fit well the Langmuir adsorption isotherm model with 0.99 regression coefficient. Release of alkali and alkaline earth metal cations (Na +, K +, Ca 2+, Mg 2+) and protons H + from MPW, during the uptake of Cu 2+, Ni 2+, and Zn 2+, and EDX analysis of MPW, before and after the metal sorption process, revealed that ion exchange was the main mechanism of sorption. FTIR analysis showed that carboxyl and hydroxyl functional groups were involved in the sorption of Cu 2+, Ni 2+, and Zn 2+. MPW was also shown to be highly effective in removing metal ions from the genuine electroplating industry effluent samples as it removed all the three metal ions to the permissible levels of discharge legislated by environment protection agencies. This study indicates that MPW has the potential to effectively remove metal ions from industrial effluents. 相似文献
10.
Poly(acrylamide) (PACM) used in this study was prepared through an effective atom transfer radical polymerization process and characterized by NMR, FTIR, and thermo gravimetric analysis. Resulting polymer was used for the uptake of heavy metal ions from aqueous solution. Partition coefficient, retention capacity, and metal ion uptake behavior in aqueous solution of PACM at different monomer percent conversions and effect of parameters for optimization of polymerization reaction gives thermally stable PACM. Efficiency of metal ion uptake of different molecular weights of PACM were tested in batches for Ni 2+, Pb 2+, Cu 2+, Zn 2+, and Hg 2+ ions in single metal solution. Metal ion sorption capacities increase with increase in polymer concentration. Metal ion sorption capacities in single metal system were 6.3 mg g ?1 Ni 2+, 6.0 mg g ?1 Pb 2+, 6.9 mg g ?1 Cu 2+, 6.2 mg g ?1 Zn 2+, 22.4 mg g ?1 Hg 2+ for PACM of 88% conversion (Mn = 19,850). Uptake by the PACM indicates that they are effective in removing metal ions from single metal ion solutions. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 相似文献
11.
Poly(acrylamide- co-itaconic acid) (AAm/IA) and poly(acrylamide- co-monomethoxyethyl itaconate) (AAm/MEI) hydrogels (HGs) synthesized at different molar ratios were used to study the adsorption of some metal ions as Cu 2+, Ni 2+, Pb 2+, Cd 2+, and Fe 3+ in aqueous solutions at different concentration: 10, 50, 100, 500, and 1000 mg L −1. Statistical analysis was performed and the effect of the metal ion, ion concentration, and hydrogel (HG) composition, on adsorption and adsorption efficiency, was evaluated for both HGs studied (AAm/IA and AAm/MEI) and each factor gave rise to significant differences ( P ≤ 0.05). The adsorption depends on the type of ion, its concentration, and also influenced by the type and composition of the HGs. For each system the adsorption efficiencies for all ions were similar with exception of Fe 3+, which showed the highest adsorption efficiency in AAm/MEI HG, but the less for the AAm/IA. For both systems, the maximum adsorption efficiency was observed when the molar ratio AAm/IA or AAm/MEI is 80/20. When the adsorption was carried out with individual ions, AAm/MEI HG was more efficient than AAm/IA. For a multielement sample of Cu 2+, Ni 2+, Pb 2+, and Cd 2+, both HGs could adsorb all the ions and their behavioral trend was the same in both cases, in which the adsorption efficiency was Pb 2+ > Cu 2+ > Cd 2+ > Ni 2+. The results of the statistical analysis evidence the advantage of its use in this type of studies. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 46999 相似文献
12.
Two novel chitosan derivatives—crosslinked chitosan dibenzo‐16‐ c‐5 acetate crown ether (CCTS‐1) and crosslinked chitosan 3,5‐di‐ tert‐butyl dibenzo‐14‐ c‐4 diacetate crown ether (CCTS‐2)—were synthesized by the reaction of crosslinked chitosan with dibenzo‐16‐ c‐5 chloracetate crown ether and 3,5‐di‐ tert‐butyl dibenzo‐14‐ c‐4 dichloracetate crown ether with the intent of forming polymers that could be used in hazardous waste remediation as toxic metal‐binding agents in aqueous environments. Their structures were confirmed with elemental analysis, infrared spectral analysis, and X‐ray diffraction analysis. In the infrared spectra of CCTS‐1 and CCTS‐2, the characteristic peaks of aromatic backbone vibration appeared at 1595 cm −1 and 1500 cm −1; the intensity of the N H and O H stretching vibration in the region of 3150–3200 cm −1 decreased greatly. The X‐ray diffraction analysis showed that the peak at 2θ = 20° decreased greatly in CCTS‐1 and CCTS‐2. The adsorption and selectivity properties of CCTS‐1 and CCTS‐2 for Pb 2+, Cu 2+, Cr 3+, and Ni 2+ were studied. Experimental results showed that the two crosslinked chitosan derivatives had not only good adsorption capacities for Pb 2+, Cu 2+, but also high selectivity for Pb 2+, Cu 2+ in the coexistence of Ni 2+. For aqueous systems containing Pb 2+, Ni 2+, or Cu 2+, Ni 2+, CCTS‐1 only adsorbed Pb 2+ or Cu 2+. For aqueous systems containing Pb 2+, Cr 2+ and Ni 2+, CCTS‐2 had high adsorption and selectivity properties for Pb 2+. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 2069–2074, 1999 相似文献
14.
Sequestration and removal of heavy metal ions from aqueous solutions pose multiple challenges. Ease of synthesis, high adsorption capacity and ease of regeneration are important considerations in the design of polymeric adsorbent materials developed for this purpose. To meet this objective, a new approach was used to design and synthesize a highly porous polystyrene-based resin (IDASR15) bearing iminodiacetate functional groups in every repeat unit by free radical polymerization with N, N'-methylenebisacrylamide as crosslinker followed by base hydrolysis. The physiochemical chemical properties of the resin were characterized by Fourier transform infrared spectroscopy, scanning electron microscope, equilibrium swelling value (ESV) and thermogravimetric analysis. Metal uptake capacity of IDASR15 towards low concentrations of various toxic heavy metal ions such as Cu 2+, Cd 2+, Mn 2+, Zn 2+, Pb 2+, Ni 2+, Co 2+, Co 3+, Cr 3+, Fe 2+, Fe 3+, and Al 3+ were investigated from their aqueous solution by batch method and found to be 0.943–2.802 mmol/g. The maximum capacity was 2.802 mmol/g obtained for Cu 2+ ion at pH 5. The potential for regeneration and reuse has been demonstrated with Cu 2+ ion by batch and column methods. The reported results suggest that IDASR15 is a highly efficient and porous complexing agent for commonly found toxic metal ions in aqueous streams with a high ESV of 68.55 g of water/1.0 g of IDASR15. It could also be reused ~99.5% of adsorption efficiency which is very promising and holds significant potential for waste-water treatment applications. 相似文献
15.
We have prepared a novel kind of magnetic nanoparticle with high adsorption capacity and good selectivity for Pb 2+ ions by modifying the magnetic nanoparticles with polyvinyl alcohol (PVA) and thiourea. The resultant magnetic nanoparticles were used to adsorb Pb 2+ ions from aqueous solution. The influence of the solution pH, the adsorption time, the adsorption temperature, coexisting ions, and the initial concentration of Pb 2+ ions on the adsorption of Pb 2+ ions were investigated. The results indicated that Pb 2+ ions adsorption was an endothermic reaction, and adsorption equilibrium was achieved within 30 min. The optimal pH for the adsorption of Pb 2+ ions was pH 5.5, and the maximum adsorption capacity of Pb 2+ ions was found to be 220 mg/g. Moreover, the coexisting cations such as Ca 2+, Co 2+, and Ni 2+ had little effect on adsorption of Pb 2+ ions. The regeneration studies showed that thiourea functionalized PVA‐coated magnetic nanoparticles could be reused for the adsorption of Pb 2+ ions from aqueous solutions over five cycles without remarkable change in the adsorption capacity. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40777. 相似文献
16.
In the preparation of fluorescent carbon nanoparticles, formation of non-fluorescent carbon particles (CPs) as waste matter is indispensible. This work is introducing CPs as adsorbents for some toxic metal ions in aqueous medium. CPs were characterised and their particle size, surface area, porosity, morphology etc. were compared with their parent material (charcoal). The effects of the initial metal ion concentration, contact time and pH on adsorption were undertaken. Adsorption data were evaluated for Langmuir and Freundlich isotherm models. The adsorption capacities (mg/g) of Ni 2+, Pb 2+, Zn 2+, Co 2+, Cd 2+ and Cu 2+ were 85, 76, 75, 67, 58 and 46, respectively. 相似文献
17.
In this work, Fe 3O 4@SiO 2-(-NH 2/-COOH) nanoparticles were synthesized for the removal of Cd 2+, Pb 2+ and Zn 2+ ions from wastewater. The results of characterization showed that Fe 3O 4@SiO 2-(-NH 2/-COOH) was superparamagnetic with a core–shell structure. The surface of Fe3O4 was successfully coated with silica and modified with amino groups and carboxyl groups through the use of a silane coupling agent, polyacrylamide and polyacrylic acid. The dispersion of the particles was improved, and the surface area of the Fe3O4@SiO2-(-NH2/-COOH) nanoparticles was 67.8 m 2/g. The capacity of Fe 3O 4@SiO 2-(-NH 2/-COOH) to adsorb the three heavy metals was in the order Pb 2+ > Cd 2+ > Zn 2+, and the optimal adsorption conditions were an adsorption dose of 0.8 g/L, a temperature of 30°C and concentrations of Pb 2+, Cd 2+ and Zn 2+ below 120, 80 and 20 mg/L, respectively. The maximum adsorption capacities for Pb 2+, Cd 2+ and Zn 2+ were 166.67, 84.03 and 80.43 mg/g. The adsorption kinetics followed a pseudo-second-order model and Langmuir isotherm model adequately depicted the isotherm adsorption process. Thermodynamic analysis showed that the adsorption of the three metal ions was an endothermic process and that increasing the temperature was conducive to this adsorption. 相似文献
18.
Reusability and selective adsorption toward Pb 2+ with the coexistence of Cd 2+, Co 2+, Cu 2+ and Ni 2+ ions on chitosan/P(2-acrylamido-2-methyl-1-propanesulfonic acid- co-acrylic acid) [CS/P(AMPS- co-AA)] hydrogel, a multi-functionalized adsorbent containing –NH 2, –OH, –COOH and –SO 3H groups was studied. The CS/P(AMPS- co-AA) was prepared in aqueous solution by a simple one-step procedure using glow discharge electrolysis plasma technique. The reusability of adsorbent in HNO 3, EDTA-2Na and EDTA-4Na was investigated in detail. The competitive adsorption of the metal ions at the initial stage was compared between their equal mass concentration and equal molar concentration. In addition, the adsorption mechanism of the adsorbent for adsorption of Pb 2+ was also analyzed by XPS. The results showed that the optimum pH of adsorption was 4.8, and time of adsorption equilibrium was about 180 min. Adsorption kinetics fitted well in the pseudo second-order model. The equilibrium adsorption capacities of Pb 2+, Cd 2+, Co 2+, Cu 2+, and Ni 2+ at pH 4.8 were obtained as 673.3, 358.3, 176.7, 235.0 and 171.7 mg g ?1, in their given order. The adsorbent displayed an excellent reusability using 0.015 mol L ?1 EDTA-4Na solution as the eluent, and the desorption ratio could not correctly reflect the true characteristics of adsorption/desorption process. Moreover, the adsorbent showed good adsorption selectivity for Pb 2+. The molar adsorption capacity at the initial stage with equal molar concentration was more reliable than the mass adsorption capacity during the study of selective adsorption. According to the XPS results, the adsorption of Pb 2+ ions by the CS/P(AMPS- co-AA) absorbent could be attributed to the coordination between N atom and Pb 2+ and ion-exchange between Na + and Pb 2+. 相似文献
19.
A reusable chelating fiber containing polyamino–polycarboxylic acid ligands was prepared via the stepwise modification of polyacrylonitrile fiber with diethylenetriamine and chloroacetic acid. The amination and carboxylmethylation conditions were optimized, and the modified fiber was characterized by elemental analysis, XRD, SEM and FTIR. For Cd 2+ in water, this chelating fiber has prominent adsorption abilities such as low adsorption limitation (0.001 mg/L), high adsorption capacity (1.34 mmol/g) and fast response speed (half-saturation adsorption time less than 0.5 min based on 1 mg/mL Cd 2+). The effectiveness of this chelating fiber has been proved by using it to treat actual sewage water, where the concentration of Cd 2+ was reduced from 0.540 to below 0.001 mg/L. This level easily meets drinking water standards (0.003 mg/L) issued by the World Health Organization. Moreover, this chelating fiber is also very effective at treating other metal ions such as Cu 2+, Ca 2+, Zn 2+, Mg 2+, Pb 2+, Ni 2+, Ag + and Hg 2+. 相似文献
20.
Peanut skin, when treated with formaldehyde to polymerize tannins, is a highly efficient substrate for removal of many heavy metal ions from aqueous waste solutions. The ions Ag 1+, Cd 2+, Cr 6+, Cu 2+, Hg 2+, Ni 2+, Pb 2+, Zn 2+, as well as Ca 2+ and Mg 2+, were contacted with formaldehyde-treated peanut skin. Quantitative removal could be achieved with Ag 1+, Cd 2+, Cu 2+, Hg 2+, Pb 2+, and Zn 2+. Capacity of the substrate for ions was promising for Pb 2+ (2.1 meq/g substrate), Cu 2+ (3.0 meq/g), and Cd 2+ (1.3 meq/g). Sorption from a solution containing Cd 2+, Cu 2+, Hg 2+, Ni 2+, Pb 2+, Zn 2+, on a packed column of formaldehyde-treated peanut skin indicated that Hg 2+, Pb 2+, and Cu 2+ were rapidly and completely bound to the packing, while Cd 2+, Ni 2+, and Zn 2+ were poorly bound until the preferred ions had been removed from solution. 相似文献
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