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1.
Molecular recognition based Fe3+ imprinted poly(GMA-MAC) (MIP) beads embedded PHEMA composite cryogel was prepared for selective removal of Fe3+ ions from β-thalassemia patient plasma. The precomplexation was achieved by the coordination of Fe3+ ions with N-methacryloyl-(L )-cysteine methyl ester (MAC-Fe3+). MIP beads were prepared by dispersion polymerization in the presence of MAC-Fe3+ complex and glycidyl methacrylate (GMA) monomer. Then the MIP beads were embedded into poly(hydroxyethyl methacrylate) (PHEMA) cryogel. The specific surface area and the swelling degree of the PHEMA-MIP composite cryogel were found to be 76.8 m2/g and 7.7 g H2O/g cryogel, respectively. The maximum adsorption amount of Fe3+ ions was 2.23 mg/g. The relative selectivity of PHEMA-MIP composite cryogel towards the Fe3+ ions was 135.0, 61.4, and 57.0 times greater than that of the PHEMA-NIP cryogel as compared with the Ni2+, Zn2+, and Fe2+ ions, respectively. PHEMA-MIP composite cryogel was recovered and reused many times without any significant decrease in its adsorption capacity. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012  相似文献   

2.
Batch adsorption experiments were carried out to remove heavy metal ions such as Cu (II), Ni (II), Cd (II), and Cr (VI) from single‐metal solutions using a polyaniline/palygorskite (PP) composite. Different parameters affecting the adsorption capacity such as contact time and pH of the solution have been investigated. The structural characteristics of the PP composite were studied in this work. Atomic absorption spectroscopy was used for the measurement of heavy metal contents, and the adsorption capacity (qe) calculated were 114 mg Cu (II) g?1, 84 mg Ni (II) g?1, 56 mg Cd (II) g?1, and 198 mg Cr (VI) g?1 under optimal conditions. The removal of the metal ions from solutions was assigned to chelation, ionic exchange, and electrostatic attraction. Data from this study proved that the novel organic/inorganic composite presents great potential in the recovery and elimination of noble or heavy metal ions from industrial wastewater. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.  相似文献   

3.
Thiourea‐formaldehyde (TUF), a well‐known chelating resin, has been synthesized and it was used in the adsorption, selective separation, and concentration of Pd(II) ions from Fe(III), Co(II) Ni(II), and Cu(II) base metal ions. The composition of the synthesized resin was determined by elemental analysis. The effect of initial acidity/pH and the adsorption capacity for Pd(II) ions were studied by batch technique. The adsorption and separation of Pd(II) were then examined by column technique. FTIR spectra and SEM/EDS analysis were also recorded before and after the adsorption of Pd(II). The optimum pH was found to be 4 for the adsorption. The adsorption data fitted well to the Langmuir isotherm. The maximum adsorption capacity of the TUF resin for Pd(II) ions was found to be 31.85 mg g−1 (0.300 mmol g−1). Chelating mechanism was effective in the adsorption. Pd(II) ions could be separated efficiently from Fe(III), Cu(II), Ni(II), and Co(II) ions using TUF resin. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011  相似文献   

4.
Modified activated carbon are carbonaceous adsorbents which have tetrabutyl ammonium iodide (TBAI) and sodium diethyl dithiocarbamate (SDDC) immobilised at their surface. This study investigates the adsorption of toxic ions, copper, zinc, chromium and cyanide on these adsorbents that have undergone surface modification with tetrabutyl ammonium (TBA) and SDDC in wastewater applications. The modification technique enhance the removal capacity of carbon and therefore decreases cost-effective removal of Cu(II), Zn(II), Cr(VI) and CN from metal finishing (electroplating unit) wastewater. Two separate fixed bed modified activated carbon columns were used; TBA-carbon column for cyanide removal and SDDC-carbon column for multi-species metal ions (Cu, Zn, Cr) removal. Wastewater from electroplating unit containing 37 mg l−1 Cu, 27 mg l−1 Zn, 9.5 mg l−1 Cr and 40 mg l−1 CN was treated through the modified columns. A total CN removal was achieved when using the TBA-carbon column with a removal capacity of 29.2 mg g−1 carbon. The TBA-carbon adsorbent was found to have an effective removal capacity of approximately five times that of plain carbon. Using SDDC-carbon column, Cu, Zn and Cr metal ions were eliminated with a removal capacity of 38, 9.9 and 6.84 mg g−1, respectively. The SDDC-carbon column has an effective removal capacity for Cu (four times), Zn (four times) and Cr (two times) greater than plain carbon.  相似文献   

5.
Molecularly imprinted polymer (MIP) for selective extraction of p-hydroxybenzoic acid (p-HB) was synthesized by suspension polymerization using p-HB as template, 4-vinyl pyridine as functional monomer and ethylene glycol dimethacrylate as crosslinker. As characterized by scanning electron microscopy, the MIP particles are spherical, with size ranging from 1 to 8 μm. Compared with the non-imprinted polymer (NIP), the MIP shows higher binding capacity toward p-HB: maximum binding capacity for p-HB being 8.07 μmol g−1 over MIP and 3.88 μmol g−1 over NIP. The adsorption of p-HB on MIP follows the Freundlich model and displays pseudo-second-order kinetics. The results of selective and competitive binding experiments confirm that the molecularly imprinted sites have excellent recognition ability toward p-HB. The results reveal that the MIP is a promising adsorbent for selective extraction of p-HB from water samples. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 46984.  相似文献   

6.
Some of the most important life-saving medications are β-lactam antibiotics (such as Penicillin G). However, these medicines have not adequately been discharged into the environment; penicillin residues offer health risks and enhance the development of resistances. Thus, its selective separation from complex matrices is a challenge worth tackling. A novel strategy of synthesis, by photopolymerization, was applied to develop magnetic molecular imprinted polymers (mag-MIPs) aiming the recognition of penicillin G (also known as benzylpenicillin). Photopolymerization, when compared with the more common thermopolymerization, has the advantage of occurring at lower temperatures, which prevents analyte degradation. The Mag-MIP presented higher surface area than the conventional MIP and good adsorption capacity of the analyte while maintaining its selectivity. The synthesized material was characterized by X-ray diffraction, showing that the magnetite nanoparticles were formed and the MIP polymerization on their surface was performed, once the material was amorphous. Furthermore, the pore formation was evaluated by BET, indicating a high surface area (832 m2 g−1) and large pore volume (0.80 cm3 g−1) in the mag-MIP compared to the magnetic non-imprinted polymer (mag-NIP: 147 m2 g−1 and 0.33 cm3 g−1). © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48496.  相似文献   

7.
A series of adsorption studies was carried out on a glycidyl methacrylate‐ modified cellulose material functionalised with imidazole (Cellulose‐g‐GMA‐Imidazole) to assess its capacity in the removal of Ni(II) ions from aqueous solution. The study sought to establish the effect of a number of parameters on the removal of Ni(II) from solution by the Cellulose‐g‐GMA‐Imidazole. In particular, the influence of initial metal concentration, contact time, solution temperature and pH were assessed. The studies indicated a Ni(II) uptake on the Cellulose‐g‐GMA‐Imidazole sorbent of approximately 48 mg g?1 of nickel from aqueous solution. The adsorption process fitted the Langmuir model of adsorption and the binding process was mildly endothermic. The kinetics of the adsorption process indicated that nickel uptake occurred within 400 min and that pseudo‐second order kinetics best describe the overall adsorption process. Nickel(II) adsorption, recovery and re‐adsorption studies indicated that at highly acidic pH values the adsorbent material becomes unstable, but in the range pH 3–6, the adsorbent is stable and shows limited but significant Ni(II) recovery and re‐adsorption capability. Copyright © 2006 Society of Chemical Industry  相似文献   

8.
In the work, poly(ethylene terephthalate) (PET) fibers were grafted with 4‐vinyl pyridine (4‐VP) monomer using benzoyl peroxide (Bz2O2) as initiator in aqueous media. The removal of Hg(II) ions from aqueous solution by the reactive fiber was examined by batch equilibration technique. Effects of various parameters such as pH, graft yield, adsorption time, initial ion concentration, and adsorption temperature on the adsorption amount of metal ions onto reactive fibers were investigated. The optimum pH of Hg(II) was found 3. The maximum adsorption capacity was found as 137.18 mg g?1. Moreover such parameters as the adsorption kinetics, the adsorption isotherm, desorption time and the selectivity of the reactive fiber were studied. The adsorption kinetics is in better agreement with pseudo‐first order kinetics, and the adsorption data are good fit with Freundlich isotherms. The grafted fiber is more selective for Hg(II) ions in the mixed solution of Hg(II)‐Ni(II), Hg(II)‐Zn(II), and Hg(II)‐Ni(II)‐Zn(II) at pH 3. Adsorbed Hg(II) ions were easily desorbed by treating with 1M HNO3 at room temperature. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012  相似文献   

9.
Sorption of Cd(II), Ni(II) and U(VI) ions onto a novel cast PVA/TiO2/APTES nanohybrid adsorbent with variations in adsorbent dose, pH, contact time, initial metal concentration and temperature has been investigated. The adsorbent were characterized by SEM and FTIR analysis. BET surface area, pore diameter and pore volume of adsorbent were 35.98 m2 g−1, 3.08 nm and 0.059 cm3 g−1, respectively. The kinetic and equilibrium data were accurately described by the double-exponential and Freundlich models for all metals. The maximum sorption capacities were 49.0, 13.1 and 36.1 mg g−1 for Cd(II), Ni(II) and U(VI) ions with pH of 5.5, 5 and 4.5, respectively. Thermodynamic studies showed that the sorption process was favored at higher temperature. The adsorbent can be easily regenerated after 5 cycles of sorption–desorption.  相似文献   

10.
Z. Elouear  J. Bouzid  N. Boujelben 《Fuel》2008,87(12):2582-2589
The removal characteristics of cadmium (Cd(II)) and nickel (Ni(II)) ions from aqueous solution by exhausted olive cake ash (EOCA) were investigated under various conditions of contact time, pH, initial metal concentration and temperature. Batch kinetic studies showed that an equilibrium time of 2 h was required for the adsorption of Ni(II) and Cd(II) onto EOCA. Equilibrium adsorption is affected by the initial pH (pH0) of the solution. The pH0 6.0 is found to be the optimum for the individual removal of Cd(II) and Ni(II) ions by EOCA. The adsorption test of applying EOCA into synthetic wastewater revealed that the adsorption data of this material for nickel and cadmium ions were better fitted to the Langmuir isotherm since the correlation coefficients for the Langmuir isotherm were higher than that for the Freundlich isotherm. The estimated maximum capacities of nickel and cadmium ions adsorbed by EOCA were 8.38 and 7.32 mg g−1, respectively. The thermodynamic parameters for the adsorption process data were evaluated using Langmuir isotherm. The free energy change (ΔG°) and the enthalpy change (ΔH°) showed that the process was feasible and endothermic respectively. As the exhausted olive cake is discarded as waste from olive processing, the adsorbent derived from this material is expected to be an economical product for metal ion remediation from water and wastewater.  相似文献   

11.
This study aimed at immobilizing Reactive Blue 2 (RB 2) dye in chitosan microspheres through nucleophilic substitution reaction. The adsorbent chemical modification was confirmed by Raman spectroscopy and thermogravimetric analysis. This adsorption study was carried out with Cu(II) and Ni(II) ions and indicated a pH dependence, while the maximum adsorption occurred around pH 7.0 and 8.5, respectively. The pseudo second-order kinetic model resulted in the best fit with experimental data obtained from Cu(II) (R = 0.997) and Ni(II) (R = 0.995), also providing a rate constant, k2, of 4.85 × 10−4 and 3.81 × 10−4 g (mg min)−1, respectively, thus suggesting that adsorption rate of metal ions by chitosan-RB 2 depends on the concentration of ions on adsorbent surface, as well as on their concentration at equilibrium. The Langmuir and Freundlich isotherm models were employed in the analysis of the experimental data for the adsorption, in the form of linearized equations. Langmuir model resulted in the best fit for both metals and maximum adsorption was 57.0 mg g−1 (0.90 mmol g−1) for Cu(II) and 11.2 mg g−1 (0.19 mmol g−1) for Ni(II). The Cu(II) and Ni(II) ions were desorbed from chitosan-RB 2 with aqueous solutions of EDTA and H2SO4, respectively.  相似文献   

12.
The aim of this study is to prepare supermacroporous cryogel with embedded ion imprinted polymer (IIP) particles which can be used for the selective removal of Tl(I) from aqueous solution. In the first step, Tl(I) has complexed with chitosan and crosslinked with ephychlorohydrin. In the second step, the supermacroporous poly(hydroxyethyl methacrylate) (PHEMA) cryogel with embedded IIP particles [PHEMA/MIP composite cryogel] which have been produced by free radical polymerization initiated by N,N,N’,N’-tetramethylene diamine (TEMED) and ammonium persulfate (APS) pair in ice bath. The template, Tl(I), has been removed from the polymer using 0.1 M EDTA solution. The cryogel is characterized by swelling test, scanning electron microscopy, and Fourier transform infrared spectroscopy. The effective parameters on Tl(I) adsorption process have evaluated by investigating the dependency of the adsorption capacity on flow-rate, Tl(I) concentration and contact time. The maximum adsorption capacity of Tl(I) ions has been found to be 1.55 µgg?1. The selectivity of the IIP biopolymer cryogel has investigated by competitive adsorption of Cd(II), Cu(II), K(I), and Fe(II). The relative selectivity coefficients of IIP biopolymer cryogel are 3.98 and 62.5 for Cd(II) and Cu(II), respectively. The IIP biopolymer cryogel could be used many times without any significant decrease in the adsorption capacity. As a conclusion it can be said that the IIP biopolymer cryogel could be used for specific separation of Tl(I) ions from nuclear, industrial, and environmental waste.  相似文献   

13.
Adsorption of toxic metal ion Pb(II) onto two different insoluble humic acids (IHAs) obtained from Beysehir (BIHA) and Ermenek (EIHA) low grade lignites and two synthesized terpolymers: styrene-divinylbenzene-methacrylic acid (SDBM) and styrene-divinylbenzene allylmethacrylate (SDBAM) were investigated and compared with commercial activated carbon (AC). The synthesized polymers were characterized by FTIR. Effects of pH (in neutral and acidic range), time, and initial metal concentration on the effectiveness of IHAs and terpolymers were determined. All synthesized adsorbents could adsorb Pb(II) with much higher capacity at half of the retention of AC in acidic medium. The adsorption capacities varied in the range of 51–76 mg g−1. The affinity order of polymers in acidic medium for Pb(II) ions was observed as: SDBAM>SDBM>BIHA≈EIHA>AC. IHAs fit Freundlich model while SDB polymers were fitting Langmuir isotherm. The maximum adsorption capacities in neutral medium were 48 mg g−1 for SDBM and 15 mg g−1 for BIHA. Desorption studies for the polymer of highest performance indicated that about 90% desorption was achieved at 5 h by using EDTA regenerant solution. The polymer can be used repeatedly in Pb(II) adsorption with close capacities to initial use. The higher selectivity of SDBAM to Pb(II) ions in multimetal solution was also indicated in the study. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012  相似文献   

14.
Molecular imprinted polymers are artificial, template-made materials with the ability to recognize and to specifically bind the target molecule. The aim of this study is to prepare supermacroporous cryogel with embedded bilirubin-imprinted particles which can be used for the selective removal of bilirubin from human plasma. N-methacryloyl-(l)-tyrosinemethylester (MAT) was chosen as the pre-organization monomer. In the first step, bilirubin was complexed with MAT and the bilirubin-imprinted poly(hydroxyethyl methacrylate-N-methacryloly-(l)-tyrosine methyl-ester) [MIP] monolith was produced by bulk polymerization. MIP monolith was smashed and the particles ground and sieved through 100 μm sieves. In the second step, the supermacroporous poly(hydroxyethyl methacrylate) (PHEMA) cryogel with embedded MIP particles [PHEMA/MIP composite cryogel] was produced by free radical polymerization initiated by N,N,N′,N′-tetramethylene diamine (TEMED) and ammonium persulfate (APS) pair in an ice bath. After that, the template (i.e., bilirubin) molecules were removed using sodium carbonate and sodium hydroxide. Compared with the PHEMA cryogel (0.2 mg/g polymer), the bilirubin adsorption capacity of the PHEMA/MIP composite cryogel (10.3 mg/g polymer) was improved significantly due to the embedded MIP particles into the polymeric matrix. The relative selectivity coefficients of PHEMA/MIP composite cryogel for bilirubin/cholesterol and bilirubin/testosterone were 8.6 and 4.1 times greater than the PHEMA cryogel, respectively. The PHEMA/MIP composite cryogel could be used many times without decreasing the bilirubin adsorption capacity significantly.  相似文献   

15.
A novel clay mineral-based adsorbent for Ag(I) ions extraction was obtained by modifying hectorite with 2-(3-(2-aminoethylthio)propylthio)ethanamine (AEPE-hectorite). The modified hectorite was used to recover Ag(I) ions from wastewater for further preparation of silver nanoparticles supported hectorite. The parameters affecting silver ions extraction by AEPE-hectorite were investigated. The adsorbent could extract Ag(I) ions from solution in a wide pH range (1–8) and high extraction efficiencies were achieved in the solution pH ranged from 4 to 9. AEPE-hectorite showed a good selectivity toward Ag(I) ions over Co(II), Ni(II) and Cd(II) ions and the solution ionic strength had no significant effect on extraction efficiency. The adsorption of Ag(I) ions onto AEPE-hectorite followed the Freundlich isotherm model with maximum adsorption capacity observed in the experiment of 49.5 mg g 1. The adsorbent was successfully used to recover silver ions from a wastewater containing high concentration of silver and silver nanoparticles supported hectorite was obtained after reducing with NaBH4. These results show an alternative in the preparation of silver nanoparticles supported clay.  相似文献   

16.
A high-surface-area activated carbon was prepared by chemical activation of Glycyrrhiza glabra residue with ZnCl2 as active agent. Then, the adsorption behavior of Pb(II) and Ni(II) ion onto produced activated carbon has been studied. The experimental data were fitted to various isotherm models. According to Langmuir model, the maximum adsorption capacity of Pb(II) and Ni(II) ions were found to be 200 and 166.7 mg g−1, respectively, at room temperature. Kinetic studies showed the adsorption process followed pseudo second-order rate model. High values of intra-particle rate constants calculated shows the high tendency of activated carbon for removal of Pb(II) and Ni(II) ions.  相似文献   

17.

The complexation–ultrafiltration technique has been introduced as a capable system to remove heavy metals ions from wastewater. This method needs a water-soluble polymer; therefore, in this paper we synthesized super water-soluble poly(itaconic acid) (PITA) and employed it in polymer-assisted ultrafiltration process to remove Pb(II) ions from synthetic wastewater solutions. The itaconic acid can be produced from different agricultural products and is a green and eco-friendly material. Factors influencing the removal of the metals ions including poly(itaconic acid) concentration, pH and permeate flux were investigated. The results showed that the maximum percentage of metal ion removal was obtained in the basic pH (pH > 7). The flux test was performed by 200 mg/L of poly(itaconic acid) and after 60 min, the flux of membrane was 33.4 L/m2h. The simultaneously selective removal ability of the poly(itaconic acid) for adsorption of different metal ions (Pb2+, Sn2+, Cu2+, Zn2+, and Cd2+) was also studied. The trend of rejection was Pb2+ > Cu2+ > Sn2+ > Zn2+ > Cd2+. The highest rejection of Pb(II) ions was achieved as 86%. Generally, the results of this research demonstrated that poly(itaconic acid) (with two carboxyl groups on its repeating unit) is more effective in removing heavy metals ions from wastewater in comparison with customary polymers.

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18.
Due to the low concentration of silver in water, most of the cellulose adsorbents exhibited low removal efficiency, which greatly limited their practical applications. Herein, a cellulose aerogel modified by thiosemicarbamide (CAT) was fabricated for reducing and adsorbing silver ions from low concentration wastewater. The characterization results concluded that CAT owned a three-dimensional spongy structure with many circular microspheres and a better specific surface area (19.37 m2 g−1), as well as the functional groups of ─C═N+─H and ─(C═S)─N. The static batch adsorption experiments demonstrated that CAT could reached the maximum removal percentage of 94.94% and adsorption capacity of 42.12 mg g−1 under the initial concentration of Ag(I) was 15 mg L−1 and the pH value was 7. Meanwhile, the adsorption of Ag(I) on CAT was second-order reaction, and the Langmuir model could better fit the adsorption process. In addition, CAT exhibited wide pH values (1–9) adaptability and excellent adsorption performance for silver through electrostatic interaction, chelation, and reduction. This study probably provides a new method as well as important experimental data and theoretical reference for the removal of silver ions and other metals.  相似文献   

19.
A new dual-template surface imprinted polymer for Cu(II) and Pb(II) was synthesized in one pot. Magnetic graphene oxide was self-assembled with low cost and environmentally benign thiourea. Presence of sulfur and nitrogen donor atoms provide hooks for coordination and partial reduction of graphene oxide matrix. It was used as an solid-phase extraction adsorbent for extraction, preconcentration, and coupled with flame atomic absorption spectrometry to manifest performance comparable with inductively coupled plasma atomic emission spectrometry (ICPAES) both in terms of quantification limit as well as interference. The critical experimental parameters such as pH; 4.6, contact time of 15 min and initial concentration of 777 (Qe; 227 mg g−1) and 800 μg L−1 (Qe; 273 mg g−1) for Cu(II) and Pb(II), respectively, were optimized using RSM-CCD and artificial neural network. The adsorption process was kinetically faster (50% adsorption in 5 min), following fractal-like-pseudo-second-order (FLPSO) kinetics and Brouers–Sotolongo isotherm model owing to the heterogenous energy landscape. The imprinting factors were in the range of 4–7 in the presence of all coexisting ions. The proposed method was robust in the determination and removal of Cu(II) and Pb(II) from food, ground water, and industry effluents with low limit of detection (Cu(II); 1.03 μg L−1 & Pb(II); 1.79 μgL−1). Spiking and recovery tests were used to assess the method's accuracy. Cu(II)/Pb(II) loaded dual template IIP (DIIP) was utilized to remove anionic dyes with >95% efficiency. Thorough examination of the method and material selectivity (in binary, ternary, and multielement system), multi fold applications of determination, removal of Cu(II), Pb(II), and removal of anionic dyes makes DIIP a promising candidate for environmental remediation.  相似文献   

20.
A novel polyvinyl alcohol/alginate/zeolite nanohybrid adsorbent for the adsorption of Ni(II) and Co(II) metal ions was prepared by the casting method. The prepared adsorbent was characterized by Fourier transform infrared spectroscopy, scanning electron microscopy as well as Barrett-Joyner-Halenda and Brunauer-Emmett-Teller analyses. The optimum adsorption conditions in terms of content of zeolite nanoparticles, adsorbent dosage, and initial pH were determined. The kinetic data for both ions were well described by the double-exponential kinetic model. The obtained Langmuir maximum adsorption capacities of Ni(II) and Co(II) metal ions were 81.51 and 79.58 mg g−1, respectively. The adsorption/desorption experiments showed a good performance after 5 cycles of adsorption.  相似文献   

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