共查询到20条相似文献,搜索用时 31 毫秒
1.
Horia M. M. Nizam El‐Din 《应用聚合物科学杂志》2002,86(7):1607-1614
A hydrogel based on gamma‐radiation polymerization of acrylic acid (AAc) in the presence of 2‐mercaptobenzimidazole (MBI) and a crosslinking agent was prepared. The properties of this AAc/MBI hydrogel were characterized in terms of gel content, swelling in different solvents, structure morphology, and IR spectroscopy. Moreover, the thermal decomposition behavior of the prepared hydrogel was investigated by thermogravimetric analysis (TGA). The TGA thermograms were also used to determine the different kinetic parameters such as order of reaction and activation energy. The sorption of some divalent metal ions such as Cu2+, Pb2+, Cd2+, and Hg2+ by the AAc/MBI hydrogel also was studied. The results showed that the AAc/MBI hydrogel has a higher tendency to swell in water and polar solvents than in nonpolar solvents. The highest metal uptake by the hydrogel was found for Hg2+ and Cd2+, whereas the lowest was for Cu2+ and Pb2+ ions. The ratios between the distribution coefficients of the different metals [separation factors (SF)] indicate that the hydrogel has a high selectivity for Hg2+ over Cu2+ (SF = 10.923) and Pb2+ (SF = 19.110). However, the hydrogel prefers Hg2+ over Cd2+ (SF = 1.356) and showed a high selectivity for Cd2+ over Cu2+ (SF = 7.822) and Pb2+ (SF = 7.240). © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1607–1614, 2002 相似文献
2.
Nazia Iqbal Mohammad Mobin M.Z.A. Rafiquee Hamad A. Al-Lohedan 《Chemical Engineering Research and Design》2012
A new cationic exchange material, sodium bis(2-ethylhexyl) sulfosuccinate (AOT) with cerium (IV) phosphate (AOT–CeP) has been synthesized. The characterization of the ion exchanger was performed by using infra red spectroscopy (IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), thermo gravimetric analysis/differential thermo gravimetric analysis (TGA/DTA/DTG) and elemental analysis. The ion exchange properties like ion exchange capacity, elution and concentration behavior of AOT–CeP were determined by taking the material into a column and elution of H+ was done by NaNO3. The thermal stability of the ion exchanger was studied by determining ion exchange capacity after heating to different temperatures for one hour. The adsorption studies on AOT–CeP demonstrated that the material is selective for Cu2+, Pb2+, Cd2+, Zn2+ and Hg2+ ions. AOT–CeP was found to be effective for the separation of Cu2+, Pb2+, Cd2+, Zn2+ and Hg2+ ions in the presence of alkali metals/alkaline earth metals. This cationic exchanger was also effective for the removal of Cu2+, Pb2+, Cd2+, Zn2+ and Hg2+ ions in the presence of acid and other transition metal ions. Thus, AOT–CeP can be used for the removal of these ions from the waste water during its treatment. 相似文献
3.
Dextrin as a biodegradable natural polymer has hydrophilic nature that capable to increase the swelling properties and biodegradability of the synthetic hydrogels. This study describes the synthesis of a poly (acrylic acid-co-acryloyl tetrasodium thiacalix[4]arene tetrasulfonate) grafted dextrin superabsorbent hydrogels (ADA) via solution polymerization. The effects of acryloyl tetrasodium thiacalix[4]arene tetrasulfonate (ACSTCA) dose (20–60) on swelling properties of the hydrogels were studied. The synthesized hydrogels were characterized by FTIR, TGA, DMTA and rheometry. The metal ion removal capacity of the gels was investigated by atomic absorption for Cd2+, Pb2+, and Hg2+. The tendency of metal ions adsorption decreased in the order of Pb2+>Cd2+>Hg2+. The effect of key operating parameters including ACSTCA content, contact time, adsorbent dosage, solution pH, and crosslinker density was experimentally studied on Pb2+ adsorption from aqueous solution. The equilibrium data was analyzed using Langmuir and Freundlich adsorption isotherms. Our experimental data are in best agreement with Freundlich isotherms, and adsorption of metal cation onto hydrogel followed a pseudo second-order kinetic model. According to the thermodynamic parameters, the adsorption of Pb2+ occurred spontaneously. The hydrogels could be regenerated after releasing heavy metal ions, and reused 5 times with less than 7 % loss of adsorption capacity. 相似文献
4.
《分离科学与技术》2012,47(9):1349-1355
A new silica gel material covalently bonded with 1-(pyridin-2-yl) imine (SiNPn) was synthesized and well characterized by elemental analysis, FT–IR, 13C NMR of the solid state, nitrogen adsorption-desorption isotherm, BET surface area, B.J.H. Pore sizes, thermogravimetry curves (TGA), and scanning electron microscope (SEM). The new chelating surface exhibits good chemical and thermal stability. The adsorption capabilities of this new system towards toxic metal ions (Hg2+, Cd2+, Pb2+, and Zn2+) were investigated using the batch method. The percentage limits of extraction were determined by atomic absorption measurements. 相似文献
5.
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 Ag1+, Cd2+, Cr6+, Cu2+, Hg2+, Ni2+, Pb2+, Zn2+, as well as Ca2+ and Mg2+, were contacted with formaldehyde-treated peanut skin. Quantitative removal could be achieved with Ag1+, Cd2+, Cu2+, Hg2+, Pb2+, and Zn2+. Capacity of the substrate for ions was promising for Pb2+ (2.1 meq/g substrate), Cu2+ (3.0 meq/g), and Cd2+ (1.3 meq/g). Sorption from a solution containing Cd2+, Cu2+, Hg2+, Ni2+, Pb2+, Zn2+, on a packed column of formaldehyde-treated peanut skin indicated that Hg2+, Pb2+, and Cu2+ were rapidly and completely bound to the packing, while Cd2+, Ni2+, and Zn2+ were poorly bound until the preferred ions had been removed from solution. 相似文献
6.
The individual and competitive adsorption capacities of Pb2+, Cu2+ and Cd2+ 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 Pb2+, 24.49 mg/g for Cu2+ and 10.86 mg/g for Cd2+ 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 Pb2+>Cu2+>Cd2+. The Langmuir adsorption model can represent experimental data of Pb2+ and Cu2+ well, but does not provide a good fit for Cd2+ adsorption data. The effects of solution pH, ionic strength and CNT dosage on the competitive adsorption of Pb2+, Cu2+ and Cd2+ 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
7.
Jae-Young Lee Tae-Soon Kwon Kitae Baek Ji-Won Yang 《Journal of Industrial and Engineering Chemistry》2009,15(3):354-358
Single and binary metal systems were employed to investigate the removal characteristics of Pb2+, Cu2+, Cd2+, and Zn2+ by Chlorella sp. HA-1 that were isolated from a CO2 fixation process. Adsorption test of single metal systems showed that the maximum metal uptakes were 0.767 mmol Pb2+, 0.450 mmol Cd2+, 0.334 mmol Cu2+ and 0.389 mmol Zn2+ per gram of dry cell. In the binary metal systems, the metal ions on Chlorella sp. HA-1 were adsorbed selectively according to their adsorption characteristics. Pb2+ ions significantly inhibited the adsorption of Cu2+, Zn2+, and Cd2+ ions, while Cu2+ ions decreased remarkably the metal uptake of Cd2+ and Zn2+ ions. The relative adsorption between Cd2+ and Zn2+ ions was reduced similarly by the presence of the other metal ions. 相似文献
8.
Water‐insoluble polyaspartyl polymers were synthesized by using water as medium instead of organic medium. Taking Ca2+ as a reference, the binding of several heavy‐metal ions, including Pb2+, Cd2+, Hg2+, Cr3+, Cu2+, and Mn2+, by polyaspartyl polymers was studied. The experimental results revealed that polyaspartate is an excellent binding agent for the investigated heavy‐metal ions. These cation ions were bound to polyaspartate polymer by the same mechanism as Pb2+, which can be explained by ion exchange model. Since polyaspartate has a protein‐resembling structure that is sensitive to trace heavy metal, it was used to remove some trace heavy‐metal elements in Chinese herbal medicines. It was found that polyaspartate material was an effective agent for the removal of Pb2+, Cd2+, and Hg2+ ions from glycyrrhizin, angelica, and gynostemma pentaphyllum. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007 相似文献
9.
《分离科学与技术》2012,47(4):854-873
Abstract Metal ion binding with a flowing system to a biosorbent comprised of cultured cell-wall fragment within a polysilicate matrix has been investigated. Solutions containing 0.10 mM Pb2+, Cu2+, Ni2+, Cd2+, and Zn2+ were exposed to the material in combinations of two, three, and five metals while simultaneously monitoring the concentration of all metals in the effluent stream. A relative affinity order of Pb2+ > Cu2+ >> Zn2+ ≈ Cd2+ > Ni2+ was determined when all five metal ions were exposed to the material. Lower-affinity metal ions were exposed to the material sequentially. Both metal-specific and common binding sites were observed for each metal ion. The presence of both binding sites that are common to all metal ions investigated and sites that appear to be unique for each metal ion could significantly impact the utility of single-metal ion studies on the application of such biosorbents for the selective removal of metal ions from natural water. 相似文献
10.
In this study, L-cystein modified bentonite-cellulose (cellu/cys-bent) nanocomposite was synthesized and characterized by XRD, FTIR, SEM with EDS, TGA, and TEM techniques. In order to optimize the process the effect of various operational parameters such as pH, adsorbent dosage, contact time, and temperature were also investigated. The adsorption experiments were carried out in initial concentrations range of 20-100 mg L?1and the adsorbent affinity for metal ions was found to be in order of Cu2+ > Pb2+ > Cd2+. The optimum pH for adsorption of Cu2+ and Cd2+ was observed at 5 while for Pb2+ it was pH 6. Based on the Langmuir model, the maximum adsorption capacity of Cu2+, Pb2+, and Cd2+ at 50?C was found to be 32.36, 18.52, and 16.12 mg g?1, respectively. The Langmuir isotherm and pseudo-second order model were found to be better fitted than the other isotherms and kinetic models. The results of thermodynamic parameters confirmed the process to be endothermic and spontaneous in nature. 相似文献
11.
A copolymer (4‐HAOF) prepared by condensation of 4‐hydroxyacetophenone and oxamide with formaldehyde in the presence of an acid catalyst proved to be a selective chelating ion‐exchange copolymer for certain metals. Chelating ion‐exchange properties of this copolymer were studied for Fe3+, Cu2+, Ni2+, Co2+, Zn2+, Cd2+, Pb2+, and Hg2+ ions. A batch equilibrium method was employed in the study of the selectivity of metal‐ion uptake involving the measurements of the distribution of a given metal ion between the copolymer sample and a solution containing the metal ion. The study was carried out over a wide pH range and in media of various ionic strengths. The copolymer showed a higher selectivity for Fe3+ ions than for Co2+, Zn2+, Cd2+, Pb2+, Cu2+, Ni2+, and Hg2+ ions. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 787–790, 2003 相似文献
12.
Lokman Uzun Ali Kara Bilgen Osman Erkut Yılmaz Necati Beşirli Adil Denizli 《应用聚合物科学杂志》2009,114(4):2246-2253
The aim of this study was to prepare magnetic beads that could be used for the removal of heavy‐metal ions from synthetic solutions. Magnetic poly(ethylene glycol dimethacrylate–1‐vinyl‐1,2,4‐triazole) [m‐poly(EGDMA–VTAZ)] beads were produced by suspension polymerization in the presence of a magnetite Fe3O4 nanopowder. The specific surface area of the m‐poly(EGDMA–VTAZ) beads was 74.8 m2/g with a diameter range of 150–200 μm, and the swelling ratio was 84%. The average Fe3O4 content of the resulting m‐poly(EGDMA–VTAZ) beads was 14.8%. The maximum binding capacities of the m‐poly(EGDMA–VTAZ) beads from aquous solution were 284.3 mg/g for Hg2+, 193.8 mg/g for Pb2+, 151.5 mg/g for Cu2+, 128.1 mg/g for Cd2+, and 99.4 mg/g for Zn2+. The affinity order on a mass basis was Hg2+ > Pb2+ > Cu2+ > Cd2+> Zn2+. The binding capacities from synthetic waste water were 178.1 mg/g for Hg2+, 132.4 mg/g for Pb2+, 83.5 mg/g for Cu2+, 54.1 mg/g for Cd2+, and 32.4 mg/g for Zn2+. The magnetic beads could be regenerated (up to ca. 97%) by a treatment with 0.1M HNO3. These features make m‐poly(EGDMA–VTAZ) beads potential supports for heavy‐metal removal under a magnetic field. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
13.
《分离科学与技术》2012,47(14):2963-2986
Abstract For the functional enhancement of chelating resins containing carboxylic acids, copolymer beads were prepared by suspension polymerization of styrene (St), methyl methacrylate (MMA), and divinylbenzene (DVB) in the presence of toluene as diluent. The phenyl rings of the beads were directly chloromethylated, and the carboxylic ester groups of the beads were converted into hydroxymethyl groups by reduction followed by chlorination to give chloromethyl groups, respectively. The chelating resins containing a pair of neighboring carboxylic acid groups (NCAGs) were obtained by the alkylation of chloromethyl groups in copolymer beads with diethyl malonate in the presence of sodium hydride followed by hydrolysis using aqueous alkali solution. Accordingly, the structural effects of the resins on the adsorption of heavy metal ions were investigated. Poly(St‐co‐DVB)‐based chelating resin containing NCAGs showed adsorption abilities toward heavy metal ions like Pb2+, Cd2+, and Cu2+, whereas poly(MMA‐co‐DVB)‐based chelating resin containing NCAGs showed adsorption abilities toward heavy metal ions like Cu2+, Cd2+, and Co2+. On the other hand, poly(St‐co‐MMA‐co‐DVB)‐based chelating resin containing NCAGs showed adsorption abilities toward heavy metal ions like Pb2+, Cd2+, Hg2+, Co2+, and Cu2+: a synergistic effect on the adsorption of heavy metal ions like Pb2+, Cd2+, Hg2+, and Co2+ was observed. The adsorption ability of poly(St‐co‐MMA‐co‐DVB)‐based chelating resin among three kinds of chelating resins was relatively good. 相似文献
14.
《分离科学与技术》2012,47(7):965-974
Terpolymer resins have been synthesized by condensation of p-nitrophenol, triethylenetetramine, and formaldehyde in the presence of 2 M NaOH as a catalyst with different molar proportions of monomers. Newly synthesized terpolymers were proved to be selective chelation ion exchangers for metal ions like Fe3+, Cu2+, Ni2+, Co2+, Zn2+, Cd2+, Hg2+, and Pb2+. A batch equilibrium study was carried out over a wide pH range, shaking time, and in media of various ionic strengths of different electrolytes and shows higher selectivity for Hg2+, Cd2+, and Pb2+. Distribution ratios of metal ions were found to be increased by increasing pH of solutions; hence the resins can be used to recover certain metals from waste solutions and removal of iron from boiler water. 相似文献
15.
Hydroxybenzoic acid group has been incorporated onto guar gum by modified Porath's method of functionalization of polysaccharides. The newly synthesized guar gum 4‐hydroxybenzoic acid (GHBA) resin was characterized by Fourier‐transform infrared spectroscopy, elemental analysis, ion‐exchange capacity, column reusability, and physicochemical properties. The distribution coefficient (Kd) values and effect of pH on chelation of these metal ions using batch method were studied. The separations of mixture of Fe2+, Zn2+, Cu2+, Cd2+, and Pb2+ metal ions on GHBA resin on the basis of their distribution coefficient at various pH were also achieved using column chromatography. The effect of experimental parameters such as pH, treatment time, agitation speed, temperature, adsorbent dose, initial metal ion concentration, and flow rate on the removal of metal ions has been also studied. GHBA resin is effective adsorbents for the removal of different toxic metal ions from aqueous solutions and follows the order: Fe2+ > Zn2+ > Cu2+ > Cd2+ > Pb2+. POLYM. ENG. SCI. 2013. © 2012 Society of Plastics Engineers 相似文献
16.
Amal El-Halah Daniel Machado Nain González Jesús Contreras Francisco López-Carrasquero 《应用聚合物科学杂志》2019,136(4):46999
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 Cu2+, Ni2+, Pb2+, Cd2+, and Fe3+ 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 Fe3+, 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 Cu2+, Ni2+, Pb2+, and Cd2+, both HGs could adsorb all the ions and their behavioral trend was the same in both cases, in which the adsorption efficiency was Pb2+ > Cu2+ > Cd2+ > Ni2+. 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
17.
Anatoly I. Bortun Lyudmila N. Bortun Sergei A. Khainakov Abraham Clearfield 《溶剂提取与离子交换》2013,31(6):1541-1558
ABSTRACT The ion exchange behavior of a sulfur-modified biotite towards Pb2+, Hg2+, Co2+, Cu2+, Cd2+ and Zn2+ ions has been studied. The ion exchange isotherms of divalent cations were determined and concentration equilibrium constants as a function of metal loading were analyzed. Sulfur modified biotite exhibits high affinity for Hg2+, Pb2+, Cu2+ and Cd2+ ions in individual solutions and in the presence of electrolytes. About 200 mg Hg/g uptake in 1·10?3 M Hg2+ solution and ~ 35 mg Hg/g in groundwater simulant or an alkaline simulant 2 M in NaN03 + 1 M in NaOH was found. The possibility of a complex ion exchange and precipitation mechanism of the sulfur modified biotite towards the soft cations is proposed. 相似文献
18.
Three types of starch derivatives containing amide groups were used in removal of heavy metal ions from their solutions. These starch derivatives were poly(acrylamide)–starch graft copolymer, carbamoylethylated starch, and starch carbamate. The different factors affecting metal ion adsorption on these substrates, such as pH, metal ion concentration, type of starch derivatives, treatment time, and temperature, were studied. Results obtained indicate that the poly(acrylamide)–starch graft copolymer was a selective adsorbant for Hg2+ at pH 0.5–1. The adsorption values ofdifferent metal ions on these starch derivatives follow the order of Hg2+ > Cu2+ > Zn2+ > Ni2+ > Co2+ > Cd2+ > Pb2+. The adsorption values depend upon pH, type of starch derivative, treatment duration, and temperature. The adsorption efficiency percentage of metal ions on the three substrates follows the order of carbamoylethylated starch > poly(acrylamide) − starch graft copolymer > starch carbamate. © 1998 John Wiley & Sons, Inc. J Appl Polm Sci 69: 45–50, 1998 相似文献
19.
《分离科学与技术》2012,47(15):2535-2545
Abstract Silica gel with a specific surface area of 365 m2·g?1 and an average pore diameter of 60 Å was chemically modified with 2-mercaptoimidazole. The degree of functionalization of the covalently attached molecule, (≡SiO)3(CH2)3—MI, where MI is the 2-mercaptoimidazole bound to the silica surface by a propyl group, was 0.58 mmol·g?1. In individual metal adsorption experiments from aqueous solutions by the batch procedure, the affinity order was HgII « CdII > CuII ~ ZnII ~ PbII > MnII at solution pHs between 4 and 7. Due to the high affinity by the sulfur atom, HgII is strongly bound to the functional groups. When solution containing a mixture of HgII, CdII, CuII, ZnII, PbII, and MnII ions was passed through a column packed with the adsorbent, HgII was the only one whose adsorption and elution was not affected by the presence of other ions. 相似文献
20.
Maria Franca Brigatti Paola Frigieri Christian Gardinali Luca Medici Luciano Poppi Giancarlo Franchini 《加拿大化工杂志》1999,77(1):163-168
This work investigates the ability of natural microporous materials, such as a zeolite-rich tuff (zeolitite) and a modulated phyllosilicate (sepiolite), to remove heavy-metal ions from simulated inorganic polluted industrial wastewater. Fixed beds of sepiolite and zeolitite were percolated by a solution of Co2+, Cu2+, Zn2+, Cd2+, and Pb2+ (concentration of each cation, 2 ? 10?3 N; total concentration, 10?2 N) and were regenerated with a 2 ? 10?3 N Na+ solution. The order of decreasing affinity was, for sepiolite: Cu2+ > Zn2+ > Cd2+ > Pb2+ ? Co2+, and, for zeolitite: Pb2+ “Cd2+ > Cu2+ > Zn2+ > Co2+. After regeneration with Na+ solution, a fraction of the retained heavy metals was quickly released by the beds as follows: sepiolite, Co2+ ? Pb2+ > Cd2+ > Zn2+ > Cu2+; zeolitite, Cd2+ > Cu2+ ? Zn2+ > Co2+ > Pb2+. XRD and DTA-TGA analyses examined structural changes in the natural and final materials. 相似文献