Adsorption Behavior Of Metal Ions Research Articles

Adsorption Behavior of Cellulose and Its Derivatives toward Ag(I) in Aqueous Medium: An AFM, Spectroscopic, and DFT Study.

The aim of this study was to develop a fundamental understanding of the adsorption behavior of metal ions on cellulose surfaces using experimental techniques supported by computational modeling, taking Ag(I) as an example. Force interactions among three types of cellulose microspheres (native cellulose and its derivatives with sulfate and phosphate groups) and the silica surface in AgNO3 solution were studied with atomic force microscopy (AFM) using the colloidal probe technique. The adhesion force between phosphate cellulose microspheres (PCM) and the silica surface in the aqueous AgNO3 medium increased significantly with increasing pH while the adhesion force slightly decreased for sulfate cellulose microspheres (SCM), and no clear adhesion force was observed for native cellulose microspheres (CM). The stronger adhesion enhancement for the PCM system is mainly attributed to the electrostatic attraction between Ag(I) and the negative silica surface. The observed force trends were in good agreement with the measured zeta potentials. The scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) analyses confirmed the presence of silver on the surface of cellulose microspheres after adsorption. This study showed that PCM with a high content of phosphate groups exhibited a larger amount of adsorbed Ag(I) than CM and SCM and possible clustering of Ag(I) to nanoparticles. The presence of the phosphate group and a wavenumber shift of the P-OH vibration caused by the adsorption of silver ions on the phosphate groups were further confirmed with computational studies using density functional theory (DFT), which gives support to the above findings regarding the adsorption and clustering of Ag(I) on the cellulose surface decorated with phosphate groups as well as IR spectra.

Experimental and numerical modelling of arsenic adsorption in fixed‐bed dynamic columns packed with atlantic cod fish scales

The removal of arsenic ions from aqueous streams using the scales of Atlantic Cod species (Gadus morhua) involves adsorption and possible precipitation of its constituents, and is dependent on the number of available surface excess sites per mass unit of the bio‐adsorbent. In modelling the adsorption behaviour of metal ions, the numerical code based on surface excess theory was applied using a two‐dimensional mass transport model for determination of breakthrough characteristics in dynamic packed bed columns. Numerical simulation data, using surface excess theory, demonstrate a reasonably close agreement with experimental results from dynamic column tests. Parameters such as porosity, selectivity, flow rate, and adsorption coefficient contribute significantly to the variation in breakthrough time intervals associated with dynamic packed bed adsorption columns.

Preparation and Heavy Metal Ion Adsorption Behavior of Novel Supermagnetic Nanocomposite of Hydrophilic Thiacalix[4]arene Self-doped Polyaniline: Conductivity, Isotherm, and Kinetic Study

In the present paper, supermagnetic nanocomposite of self-doped polyaniline (PANI) was prepared by attaching hydrophilic thiacalix[4]arene tetrasulfonate protonic acid dopant as pendent groups to PANI backbone and was further magnetized with Fe3O4 via the coprecipitation method. Thereafter, the structural, morphological, and magnetic properties of the nanocomposite were studied by Fourier transform infrared, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, atomic force microscopy, vibrating sample magnetometer, and thermogravimetric analysis, and nanocomposites were further used for the removal of metal ions from aqueous solutions. The adsorption capacity of self-doped nanoadsorbent toward Cu(II), Cd(II), Co(II), and Cr(III) was investigated through batch adsorption techniques, and the extent of adsorption was measured as a function of pH, initial metal ion concentration, and contact time. It was found that the metal ion removal reached maximum at pH 8.0 and remained constant after 60 min. Experimental data were fitted to the Langmuir, Freundlich, Redlich–Peterson, and Temkin equation models with the maximum adsorption capacity calculated as 294, 285.71, 277.7, and 285.7 mg⋅g−1 from the Langmuir isotherm for Cu(II), Cd(II), Co(II), and Cr(III), respectively. The kinetic study was carried out through pseudo–first-order, pseudo–second-order, Elovich kinetic, and intraparticle diffusion models in which the related correlation coefficient for each kinetic model showed that the pseudo–second-order rate equation was better described by the adsorption process. The four-probe conductivity measurement technique revealed that metal ion adsorption resulted in a rather significant enhancement of conductivity with a 100 order of magnitude increment for the supermagnetic nanoadsorbent due to charge delocalization of absorbed metal ions.

Removal of metallic elements from industrial waste water through biomass and clay

This study reports the removal of nickel(II) and copper(II) ions (Ni2+ and Cu2+) from aqueous solution using pure and chemically pretreated biomass from Arachis hypogea (peanut shells), Prunus amygdalus (almond shells), Arundo donax (giant cane) and two clay materials, clay G and clay B. These materials are indigenous, easily available, surpulus by-products for biosorption studies. Batch experiments were carried out to determine the effect of various adsorbent factors such as initial pH, temperature, particle size and contact time on the adsorption process. For adsorption application, up to 99% removal of both metal ions was achieved by biomass and clay materials. Furthermore, chemically modified adsorbents significantly increased the uptake capacity of biomass, suggesting that the affinity between metal and sorbent can be increased after pretreatment. Equilibrium isotherms were analyzed using Langmuir and Freundlich isotherm models, and both models fitted to explain the adsorption behavior of metal ions on to biomass and clay. This shows that the adsorption of metal ions on the adsorbent is a physical adsorption mechanism. In conclusion, owing to its outstanding nickel(II) and copper(II) uptake capacity, the utilized biomass proved to be an excellent biosorbent.

콜타르피치 기반 활성탄소섬유의 제조 및 특성에 관한 연구. II. 물리적 활성화법에 의한 활성탄소섬유의 구리(II), 니켈(II) 흡착 특성

In this paper, the heavy metal ion adsorption behavior in coal tar pitch-based activated carbon fibers (ACFs) during physical activation is presented. N2 adsorption iso- therms at 77 K were examined using Brunauer-Emmett-Teller (BET), Horvath-Kawazoe (H- K), and Barret-Joyner-Halenda (BJH) methods to characterize specific surface area, pore vol- ume, and pore size distribution. The removal of heavy metal ions from ACFs was confirmed by atomic absorption spectroscopy (AAS). Experimental results for the ACFs showed a type I isothermal adsorption curve, which confirmed that the created pores were mostly micro- porous. After a 40-min steam activation, the fibers showed a high specific surface area of 1,693 m 2 /g. In addition, all heavy metal ions in the ACFs were adsorbed after about 20 min, and the adsorption reached equilibrium within 1 h. It was found that the adsorption capac- ity of the ACFs was improved by the presence of micropores but was also dependent on the specific surface area of the ACF.

Preparation and heavy metal ion adsorption behavior of novel supermagnetic nanocomposite based on thiacalix[4]arene and polyaniline: Conductivity, isotherm and kinetic study

Supermagnetic nanocomposite of polyaniline thiacalix[4]arene (Fe3O4@PANI-AmAzoTCA[4]) was prepared by coprecipitation of aniline-diaminoazo thiacalix[4]arene copolymer (PANI-AmAzoTCA[4]) and in-situ generated Fe3O4 nanoparticles. Structural, morphological and magnetic properties of the nanocomposite was studied by nuclear magnetic resonance (NMR), Fourier transform infrared (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Atomic force microscopy (AFM) and vibrating sample magnetometer (VSM), and further used for the removal of metal ions from aqueous solutions. The influence of pH, contact time and initial metal ion concentration on the adsorption efficiency was investigated. The heavy metal ion adsorption mechanism of the supermagnetic adsorbent was clarified through adsorption capacity investigation from the isotherm and kinetic point of view. The related correlation coefficient for each isotherm-model showed that the equilibrium adsorption behavior of Cd(II) ion can be applied to Langmuir model with the maximum adsorption capacity of 285.7mgg−1 and for Cu(II), Co(II) and Cr(III) ions to Temkin model with the equal maximum adsorption capacity of 312.5mgg−1. The experimental data of all metal ions fitted well with the pseudo-second-order rate equation. The four-probe technique revealed that metal ion adsorption resulted in a rather significant enhancement of conductivity with a 100 order of magnitude for the supermagnetic nanoadsorbent due to charge delocalization of absorbed metal ions.

Characterization of adsorbent microspheres of cellulose and acrylic acid and its adsorption behaviors for metal ions

Acrylic acid was grafted onto cellulose by graft copolymerization in [AMIM]Cl ionic liquids. Then, microspheres were prepared by an inverse suspension polymerization technique. The cellulose-graft-poly (acrylic acid) was confirmed by FTIR spectrum, thermo gravimetric analyzer, and a transmission electron microscope. The optimal conditions of synthesis was selected from orthogonal tests, the results of which show that the optimum reaction conditions were as follows: amount of monomer, 4 g/g cellulose (CE); dosage of initiator, 0.15 g/g CE; dosage of crosslinker, 0.05 g/g CE; reaction temperature, 60°C; and reaction time, 1.5 h. The adsorption behavior of the polymer microspheres for Cu2+ and Mn2+ ions was investigated showing that its adsorption capacity increased as initial concentration of metal ions, and contacting time increased. When pH value of solution was 5, it reached maximum adsorption amount as 201 and 175 mg/g for Cu2+ and Mn2+ ions, respectively.

Adsorption Behavior of Metal Ions with ^|^beta;-Diketone Type Chelating Agents Supported on Hydrophobized Mesoporous Silicate MCM-41

Adsorption Behavior of Metal Ions with ^|^beta;-Diketone Type Chelating Agents Supported on Hydrophobized Mesoporous Silicate MCM-41

Adsorption behavior of metal ions on alkylhistidine extractant impregnated resins: Effect of functional groups of histidine

Two types of alkylhistidine extractants, histidine-2-ethylhexyl amide (His-EH) and N-p-tert-octylphenoxyacetyl-histidine (OP-His) were prepared. The alkylhistidine extractants were impregnated onto a methacrylate-based polymer support to investigate the adsorption selectivity for metal ions. His-EH, which has coordinating imidazole and amino groups, adsorbs Cu(II), Ni(II), Zn(II) and Co(II) at pH>5. By contrast, OP-His, which has imidazole and carboxyl groups, shows adsorption selectivity; Cu(II)>Zn(II)>Ni(II)>Co(II). A column was packed with OP-His impregnated resin to investigate the separation selectivity between Cu(II) and Co(II). Cu(II) was selectively adsorbed and was efficiently concentrated to 59 times the concentration of the feed solution.

Characterization of cellulose-based electrospun nanofiber membrane and its adsorptive behaviours using Cu(II), Cd(II), Pb(II) as models

Nanofiber membranes from the composite of cellulose acetate/polyvinylpyrrolidone were prepared using electrospinning technique. After treated with water and alcoholic KOH to remove partially polyvinylpyrrolidone and deacetylate the cellulose acetate, the membranes were further functionalized with thiol groups using thioglycolic acid. Related materials were characterized using infrared and thermogravimetric analysis. And the results showed that the membranes were success of functionalisation. Then the nanofiber membranes were used in the sorption-desorption process. The effects of pH, contacting time and adsorption capacity of nanofiber membranes were studied against Cu(II), Cd(II) and Pb(II) ions. And the maximum adsorption capacities of Pb (II), Cu (II), and Cd (II) ions were estimated at 30.96, 19.63, 34.70 mg g−1. Our results suggested that the adsorption behaviour of metal ions could be described using Langmuir model. Their adsorption kinetics was in agreement with the model of pseudo-second order, suggesting chemical adsorption as the rate-limiting step of the adsorption mechanism. The durability of the thiol-functionalized cellulose nanofiber membranes was also evaluated by repetitive adsorption-desorption.

Comparative study on kinetic adsorption of Cu(II), Cd(II) and Ni(II) ions from aqueous solutions using activated sludge and dried sludge

The adsorption of Cu(II), Cd(II) and Ni(II) ions from aqueous solutions by activated sludge and dried sludge was investigated under laboratory conditions to assess its potential in removing metal ions. The adsorption behavior of metal ions onto activated sludge and dried sludge was analyzed with Weber–Morris intra-particle diffusion model, Lagergren first-order model and pseudo second-order model. The rate constant of intra-particle diffusion on activated sludge and dried sludge increased in the sequence of Cu(II) > Ni(II) > Cd(II). According to the regression coefficients, it was observed that the kinetic adsorption data can fit better by the pseudo second-order model compared to the first-order Lagergren model with R 2 > 0.997. The adsorption capacities of metal ions onto activated sludge and dried sludge followed the sequence Ni(II) ≈ Cu(II) > Cd(II) and Cu(II) > Ni(II) > Cd(II).

Separation and Evaluation of Soybean Protein Hydrolysates Prepared by Immobilized Metal Ion Affinity Chromatography with Different Metal Ions

Metal ion affinity chromatography is widely used to purify peptides on the basis of the dissimilarities of their amino acids. However, researchers are interested in the separation differences between different metal ions in this method. In our study, four kinds of commonly used metal ions are compared by the amount of immobilized metal ion on iminodiacetic acid-Sepharose and binding amount of soybean peptide to immobilized iminodiacetic acid-Mn(+) adsorbents and evaluated by high-performance liquid chromatography (HPLC) profiles. The results show that due to the different adsorption behaviors of metal ions, the binding ability order of soybean protein peptide on the column should be Fe(3+) > Cu(2+) > Zn(2+) > Ca(2+). The HPLC profiles show that peptides adsorbed by four kinds of metal ions display similar strong hydrophobic characteristics.

The Adsorption Behavior of Functional Particles Modified by Polyvinylimidazole for Cu(II) Ion

AbstractIn this paper, a novel composite material the silica grafted by poly(N‐vinyl imidazole) (PVI), i.e., PVI/SiO2, was prepared using 3‐methacryloxypropyl trimethoxysilane (MPS) as intermedia through the “grafting from” method. The adsorption behavior of metal ions by PVI/SiO2 was researched by both static and dynamic methods. Experimental results showed that PVI/SiO2 possessed very strong adsorption ability for metal ions. For different metal ions, PVI/SiO2 exhibited different adsorption abilities with the following order of adsorption capacity: Cu2+ > Cd2+ > Zn2+. The adsorption material PVI/SiO2 was especially good at adsorbing Cu(II) ion and the saturated adsorption capacity could reach up to 49.2 mg/g. The empirical Freundlich isotherm was found to describe well the equilibrium adsorption data. Higher temperatures facilitated the adsorption process and thus increased the adsorption capacity. The pH and grafting amount of PVI had great influence on the adsorption amount. In addition, PVI/SiO2 particles had excellent eluting and regenerating property using diluted hydrochloric acid solution as eluent. The adsorption ability trended to steady during 10 cycles.

Heavy metal ion adsorption behavior in nitrogen-doped magnetic carbon nanoparticles: Isotherms and kinetic study

To clarify the heavy metal adsorption mechanism of nitrogen-doped magnetic carbon nanoparticles (N-MCNPs), adsorption capacity was investigated from the adsorption isotherms, kinetics and thermodynamics points of view. The obtained results showed that the equilibrium adsorption behavior of Cr 3+ ion onto the N-MCNPs can be applied to the Langmuir model and pseudo-second-order kinetics. It indicated that the fabricated N-MCNPs had the homogenous surface for adsorption and all adsorption sites had equal adsorption energies. Furthermore, the adsorption onto N-MCNPs taken place through a chemical process involving the valence forces. According to the thermodynamics, the adsorption process is spontaneous and endothermic in nature which means that the adsorption capacity increases with increasing temperature due to the enhanced mobility of adsorbate molecules. The effects of the solution pH and the species of heavy metal ion on the adsorption uptake were also studied. The synthesized N-MCNPs exhibited an enhanced adsorption capacity for the heavy metal ions due to the high surface area and large amount of nitrogen contents.

Adsorption Behavior of Metal Ions by Amidoxime Chelating Resins

AbstractIn this work, the acrylonitrile (AN) – divinylbenzene (DVB) –methylacrylate (MA) resin was synthesized via suspension polymerization in the presence of toluene as diluent, and benzoylperoxide (BPO) as initiator. The effect of MA, toluene and alkaline treatment on the exchange capacity of the resin were investigated. The results showed that the anion exchange capacity decreased with an increase in the amount of MA, while alkaline treatment had no significant effect. Also, the cation exchange capacity increased with an increase in the amount of hydrophilic agent and reached a maximum point. The sorption equilibrium was achieved relatively fast within 40 mins, and the resin exhibited affinity towards lead (II), copper (II) and in particular uranium (VI). The adsorption of uranium was directly depended up on the pH value. Furthermore, the macroreticular chelating resin, containing amidoxime group had higher adsorption of uranium (VI) in comparison to other metal ions studied. Finally, the alkaline treatment enhanced the potential for much faster adsorption characteristics and the highly porous chelating resin provided a more favorable pore structure for the rapid rate of diffusion of metal ions.

Synthesis, characterization and analytical application of hybrid; Acrylamide zirconium (IV) arsenate a cation exchanger, effect of dielectric constant on distribution coefficient of metal ions

A new hybrid inorganic–organic cation exchanger acrylamide zirconium (IV) arsenate has been synthesized, characterized and its analytical application explored. The effect of experimental parameters such as mixing ratio of reagents, temperature, and pH on the properties of material has been studied. FTIR, TGA, X-ray, UV–vis spectrophotometry, SEM and elemental analysis were used to determine the physiochemical properties of this hybrid ion exchanger. The material behaves as a monofunctional acid with ion-exchange capacity of 1.65 meq/g for Na + ions. The chemical stability data reveals that the exchanger is quite stable in mineral acids, bases and fairly stable in organic solvents, while as thermal analysis shows that the material retain 84% of its ion-exchange capacity up to 600 °C. Adsorption behavior of metal ions in solvents with increasing dielectric constant has also been explored. The sorption studies reveal that the material is selective for Pb 2+ ions. The analytical utility of the material has been explored by achieving some binary separations of metal ions on its column. Pb 2+ has been selectively removed from synthetic mixtures containing Mg 2+, Ca 2+, Sr 2+, Zn 2+ and Cu 2+, Al 3+, Ni 2+, Fe 3+. In order to demonstrate practical utility of the material quantitative separation of the Cu 2+ and Zn 2+ in brass sample has been achieved on its columns.

Effect of Surfactants and Temperature on Adsorption Behavior of Metal Ions on Organic–Inorganic Hybrid Exchanger, Acrylamide Aluminum Tungstate

AbstractThe adsorption behavior of a thermally and chemically stable hybrid ion‐exchange material, acrylamide aluminum tungstate was explored in cationic (CTAB) and anionic (SDS) surfactants and acidic solvents. Critical micellar concentration (CMC) appears to be an important parameter in determining the adsorption behavior of metal ions. Equilibration time and temperature studies on the distribution coefficient of metal ions were studied. On the basis of the distribution coefficient, this material was successfully used for quantitative separations of some binary synthetic mixtures of metal ions by the column method. Hg(II) ion was selectively determined quantitatively in synthetic mixture. The material appears to be promising for separating toxic metal ions in a real matrix (industrial effluents and waste water) and can be utilized as a packing material in HPLC and GC columns for faster and more efficient separation.

Synthesis, characterization and analytical applications of titanium(IV) molybdosilicate: A cation ion-exchanger

A new inorganic cation exchanger titanium(IV) molybdosilicate has been synthesized. The effect of experimental parameters such as mixing ratio of reagents, temperature, and pH on the properties of material has been studied. The material was characterized on the basis of chemical composition, thermal and chemical stability, X-ray diffraction, FTIR, TGA and SEM studies. The exchanger behaves as a monofunctional acid in alkali systems and bifunctional in alkaline earth system. The cation exchange capacity for Na + was found to be 0.74 mequiv./g ions. The adsorption behavior of metal ions in different solvent systems namely acetic acid, formic acid, dimethylsulfoxide, phenol, triton, formamide and dimineralized water has been studied. The analytical applications of the material have been explored by achieving some binary as well as ternary separations from aqueous solution on its columns. In order to demonstrate analytical utility of titanium(IV) molybdosilicate, quantitative separation of Fe 3+ and Zn 2+ contents of a commercially available pharmaceutical sample viz Fefol-Z has been performed on its column.

Adsorption Behavior of Metal Ions onto a Bovine Serum Albumin (BSA) Membrane Monitored by Means of an Electrode-Separated Piezoelectric Quartz Crystal

The interaction between metal ions and bovine serum albumin (BSA) was studied by using a piezoelectric quartz crystal (PQC) arranged in the electrode-separated configuration. A silanized surface of the PQC was coated with a BSA membrane via a coupling reaction with glutaraldehyde. The frequency shifts obtained from PQC coated with a BSA membrane suggested that various kinds of metal ions could be adsorbed onto the BSA membrane from aqueous solutions containing a low concentration of metal ions (2 or 10 micromol dm(-3)), only when the BSA was denatured with an alkaline solution. Anionic species of Pt(IV) and Au(III) were adsorbed onto the denatured BSA membrane from an acetic acid solution at pH 2.2, and cationic species of Cd(II), Zn(II), Co(II), Ni(II), Cu(II), and Ag(I), and cations, such as Ca2+, Ba2+, and Mg2+, were adsorbed from ammonia buffer at pH 9.5, whereas Al(III), Cr(III), Fe(III), Hg(II), and Pb(II) were hardly adsorbed. The adsorption mechanisms of these metal ions are discussed, based on the electrostatic interaction between the metal ions and the denatured BSA membrane, and complex formation between the metal ions and amino acid residues of the denatured BSA. Further, the PQC coated with a denatured BSA membrane was applied to the determination of Pt and Cd, using large frequency shifts for Pt(IV) and Cd(II).

Metal ion adsorption behavior of poly[3‐(dimethylamine)propyl acrylate] and poly[3‐(dimethylamine)propylacrylate‐co‐acrylic acid] resins

AbstractTwo resins were synthesized by radical polymerization using N,N′‐methylene‐bis‐acrylamide and ammonium persulfate as the crosslinking reagent and initiator, respectively. The yields were 98%. The resins were characterized by FTIR and UV‐Vis spectroscopy. Sorption behavior of resins toward Hg(II), Cd(II), Zn(II), Pb(II), and Cr(III) ions was studied at different pHs depending on the metal ion. Both resins showed selective sorption to Hg(II) ions at pH 2 from a mixture of all ions.The elution of Hg(II) bound to the resins was also investigated using perchloric acid at different concentrations. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1251–1256, 2002; DOI 10.1002/app.10455