Personal Research Database

Full Text: S\Sep Sci Tec37, 2183.pdf

Abstract: The application of polyethylene (PE) powder to the adsorption of complexing dyes has been studied. Rhodamine B, aluminon, o-phenanthroline and dithizone were used as model substances of cationic, anionic, slightly polar, and apolar species, respectively. The influence of PE type, solvent, pH, and ionic strength on the adsorption was investigated. The results showed that high-density PE adsorbs polar dyes, preferentially cationic dyes, from aqueous solutions, whereas low-density PE adsorbs apolar dyes from an apolar milieu. The adsorption of polar species occurs probably at negatively charged sites on the PE surface, whereas the apolar ones occurs at the apolar parts of the surface. Presence of salts and pH influence the adsorption, mainly of anionic dyes, for these, the lower the pH the higher the adsorption, showing that the undissociated anionic dye is adsorbed. The adsorption in ethanolic solutions was very weak, probably because ethanol, differently from water, wets PE and therefore competes with the dyes for the active sites on the PE surface. Complexes formed by metallic ions and dyes are also adsorbed on PE showing that, for analytical purposes, metallic cations can be separated from their matrix solutions using adequate PE and conditions for the separation.

Keywords: Adsorption, Dyes, Polyethylene Powder

Namasivayam, C., Yamuna, R.T. and Arasi, D.J.S.E. (2002), Removal of procion orange from wastewater by adsorption on waste red mud. Separation Science and Technology, 37 (10), 2421-2431.

Full Text: S\Sep Sci Tec37, 2421.pdf

Abstract: The ability of waste red mud, an industrial by-product produced during the processing of bauxite ore, to remove procion orange was investigated at different initial dye concentrations, agitation time, adsorbent dosage, and pH. Adsorption followed the Freundlich isotherm model. A maximum removal of 82% of the dye was observed at pH 2.0. Desorption studies showed that maximum desorption occurred at a pH of 11.

Keywords: Aqueous-Solutions, Dye Adsorption, Reactive Dyes, Basic-Dyes, Equilibrium, Degradation, Adsorbents, Silica, Nickel, Color

Ruiz, M., Sastre, A. and Guibal, E. (2002), Pd and Pt recovery using chitosan gel beads. II. Influence of chemical modifications on sorption properties. Separation Science and Technology, 37 (10), 2385-2403.

Full Text: S\Sep Sci Tec37, 2385.pdf

Abstract: Chitosan is very efficient at removing precious metals from dilute acid solutions. Its sorption properties can be improved by the chemical modification of the polymer. Several methods have been tested for chitosan modification including poly(ethylene imine) (PEI)-grafting, hydrogenation of imine function on glutaraldehyde-cross-linked chitosan, and thiourea- grafting. Depending on the modification technique, the improvement in sorption performance may consist, in an increase in sorption capacity (PEI-grafted chitosan), a change in the stability of the sorbent (hydrogenation of imine linkage) or an increase in the selectivity of sorption in the presence of co- ions (thiourea derivatives of chitosan). Chitosan gel beads were chosen rather than the flaked material, since the gel beads have enhanced diffusion properties. The influence of drying and re-hydration of the beads are studied for some of these chitosan derivatives with regard to their diffusion properties.

Keywords: Beads, Brines, Capacity, Chemical, Chemical Modification, Chitosan, Cross-Linking, Diffusion, Diffusion Properties, Drying, Equilibrium, Gel, Glutaraldehyde Cross-Linking, Hydrogenation, Ion Adsorption Capacity, Mercury(II), Metal-Ions, Metals, Modification, Molybdate Sorption, N-Carboxymethyl Chitosan, Palladium, Performance, Platinum, Poly(Ethyleneimine)-Grafting, Polymer, Properties, Recovery, Removal, Resins, Selectivity, Sodium Borohydride Reduction, Sorption, Sorption Capacity, Sorption Isotherms, Sorption Kinetics, Sorption Properties, Stability, Thiourea-Grafting

Sağ, Y. and Aktay, Y. (2002), A comparative study for the sorption of Cu(II) ions by chitin and chitosan: Application of equilibrium and mass transfer models. Separation Science and Technology, 37 (12), 2801-2822.

Full Text: S\Sep Sci Tec37, 2801.pdf

Abstract: The sorption of Cu(II) by chitin, a naturally occurring material, and chitosan, prepared from chitin, was investigated and compared. The effect of pH, initial metal ion concentration, particle size, sorbent concentration, and stirring rate on sorption capacity was characterized by measuring the sorption isotherms. Sorption data of chitin and chitosan were best modeled by the Langmuir and Redlich-Peterson isotherms, although they can be modeled by the Freundlich and BET sorption models. Next, batch studies were carried out to identify the rate-controlling steps for Cu(II) sorption. Single resistance models were used in the determination of the external film mass transfer step and the intraparticle diffusion step.

Keywords: Waste-Water Treatment, Cu(II) Ions, Sorption, Chitin, Chitosan, Equilibrium Sorption Models, Mass Transfer Models, Binary Metal Mixtures, Rhizopus-Arrhizus, Activated Carbon, R-arrhizus, Biosorption, Adsorption, Copper, Chromium(VI), Derivatives, Acid

Peleanu, I., Maria Zaharescu, M., Rau, I., Crisan, M., Jitianu, A. and Meghea, A. (2002), Nanocomposite materials for As(V) removal by magnetically intensified adsorption. Separation Science and Technology, 37 (16), 3693-3701.

Full Text: S\Sep Sci Tec37, 3693.pdf

Abstract: New nanocomposite adsorbent based on silica and iron(III) oxide, thermally treated at 200°C has been used for the arsenic(V) removal. Adsorbents were prepared by sol-gel method, the iron oxides being generated in situ during the sol-gel process. Nanocomposite materials thus obtained have a convenient porosity and nanosized iron oxide content. The sorption experiments have been carried out in a batch mode by using aqueous solutions containing 1000 ppm As. The influence of different experimental parameters on the adsorption capacity was investigated. The effect of magnetic field on the enhancement of adsorption process was also revealed.

Mathialagan, T. and Viraraghavan, T. (2003), Adsorption of cadmium from aqueous solutions by vermiculite. Separation Science and Technology, 38 (1), 57-76.

Full Text: S\Sep Sci Tec38, 57.pdf

Abstract: The present study involves an investigation of a low-cost adsorbent, vermiculite for the removal of cadmium from aqueous solutions. The effects of pH and contact time on the adsorption process were examined. The optimum pH for adsorption was found to be 6. Residual cadmium concentration reached equilibrium in four hours and the rate of cadmium adsorption by Vermiculite was rapid in the first hour of the reaction time. Ho’s pseudo second order model best described the reaction rate. Batch adsorption experiments conducted at room temperature (22±1C) showed that the adsorption pattern followed the Freundlich isotherm model. The maximum removal of cadmium obtained from batch studies was 96%. Thomas model was used to describe the adsorption data from column studies. Overall, the results showed that vermiculite could be considered as a potential adsorbent for cadmium removal from aqueous solutions.

Keywords: Activated Carbon, Adsorbent, Adsorption, Adsorption Process, Aqueous Solutions, Batch, Batch Adsorption, Batch Studies, Cadmium, Cadmium Adsorption, Cd(II), Column, Column Studies, Concentration, Contact, Data, Effects, Equilibrium, Experiments, First, Fly-Ash, Freundlich, Freundlich Isotherm, Freundlich Isotherm Model, Investigation, Isotherm, Isotherm Model, Isotherms, Kinetics, Kinetics, Low Cost, Low Cost Adsorbent, Low-Cost Adsorbent, Model, Pattern, Peat, pH, Potential, Process, Pseudo, Pseudo Second Order, Pseudo-Second-Order, Removal, Room Temperature, Second Order, Second-Order, Solutions, Temperature, Thomas Model, Vermiculite, Water

? Díaz-Nava, C., Solache-Ríos, M. and Olguín, M.T. (2003), Sorption of fluoride ions from aqueous solutions and well drinking water by thermally treated hydrotalcite. Separation Science and Technology, 38 (1), 131-147.

Full Text: 2003\Sep Sci Tec38, 131.pdf

Abstract: Fluoride is a naturally occurring element in many water supplies, and it may cause fluorosis. The hydrotalcite was synthesized and characterized before and after the retention of fluoride ions by x-ray diffraction, electron microscopy, and IR. The thermally treated hydrotalcite was evaluated for the sorption of fluoride ions from aqueous solutions at pH 5, 7, and 9 and well water. It was found that the retention of fluoride ions by the material was 80% or higher. The Kd values show that the best conditions for the sorption of F^- ions from the solutions is at pH 5, and they show as well that the physicochemical properties affect the uptake process.

Keywords: Adsorption, Drinking Water, Exchange, Fluoride, pH, Sorption

? Kubota, N., Goto, I., Nakashima, Y. and Eguchi, Y. (2003), Adsorption and desorption of serum proteins using cellulosic affinity membrane modified with N-acetyl-L-phenylalanine. Separation Science and Technology, 38 (2), 323-336.

Full Text: 2003\Sep Sci Tec38, 323.pdf

Abstract: A cellulosic affinity membrane modified with N-acetyl-L-phenylalanine (N-Ac-L-Phe) was prepared intending to separate and purify the serum proteins. A porous cellulose membrane was first reacted with acrylonitrile to afford a cyanoethyl cellulose membrane (CEC membrane). After reduction of the cyano groups of the CEC membrane to obtain aminopropyl cellulose membrane (APC membrane), N-Ac-L-Phe was bound to the APC membrane through amide linkage (APC-Phe membrane). The pH dependence of the adsorption of serum proteins on the APC-Phe membrane was investigated in a dead-end flow mode, using bovine serum albumin (BSA) and gamma-globulin (BgammaG) as model proteins. The adsorption behavior of BSA and BgammaG on the APC-Phe membrane was rather independent of pH, and the amount of BSA adsorbed on the membrane was greater than that of BgammaG. The BSA adsorbed on the APC-Phe membrane was recovered with hydroxycarboxylic acid solutions, whereas, it was not effectively eluted with NaCl solution.

Keywords: Acrylonitrile, Adsorption, Affinity Membrane, Albumin, Behavior, Bovine, Bovine Serum Albumin, Bsa, Cellulose, Chromatography, Dependence, Desorption, Elution, Flow, Fractionation, Gamma-Globulin, Globulin, Ligands, Membrane, Model, Modified, pH, pH Dependence, Phenylalanine, Porous, Porous Cellulose Membrane, Proteins, Purification, Recovery, Reduction, Serum, Tannic-Acid

Jain, A.K., Gupta, V.K., Bhatnagar, A. and Suhas (2003), A comparative study of adsorbents prepared from industrial wastes for removal of dyes. Separation Science and Technology, 38 (2), 463-481.

Full Text: S\Sep Sci Tec38, 463.pdf

Abstract: Waste materials such as blast furnace dust, sludge and slag from steel plants and carbon slurry from fertilizer plants were treated and activated to prepare low-cost adsorbents. The adsorbents were chemically characterized and the surface area determined. The carbonaceous adsorbent prepared from carbon slurry had appreciable surface area (380 m²/g), whereas, the other three adsorbents had poor surface area (428 m²/g). The adsorption of three basic dyes, that is, chrysoidine G, crystal violet, and meldola blue was studied on all the adsorbents and the results indicated that only carbonaceous adsorbent removed the dyes from solution to an appreciable extent compared to the others. The carbanaceous adsorbent can, therefore, be a useful material for dye removal. All further studies were, therefore, done on the carbonaceous adsorbent. The adsorption isotherms of the dyes were found to conform to the Langmuir equation. The thermodynamic parameters calculated indicated that the dye adsorption was exothermic and physical in nature. The kinetic studies of the adsorption process showed it to be first order and pore diffusion controlled. The adsorption with the carbonaceous adsorbent is about 70-80% of the amount taken up by standard activated charcoal. Thus, the prepared carbonaceous adsorbent is efficient and can be used for the removal of dyes from solution.

Keywords: Low Cost Adsorbents, Adsorption, Basic Dyes, Carbonaceous Adsorbent, Low-Cost Adsorbent, Acid Dye, Natural Adsorbents, Aqueous-Solutions, Reactive Dyes, Adsorption, Effluent, Water, Peat, Equilibrium

Abu Al-Rub, F.A., Kandah, M. and Al-Dabaybeh, N. (2003), Competitive adsorption of nickel and cadmium on sheep manure wastes: Experimental and prediction studies. Separation Science and Technology, 38 (2), 483-497.

Full Text: S\Sep Sci Tec38, 483.pdf

Abstract: Sheep manure wastes (SMW) previously have been shown to be very efficient in removing nickel and cadmium from single-component, dilute aqueous solutions. Simultaneous removal of nickel and cadmium ions from aqueous solutions using SMW has been investigated in this study. The experimental results showed that the SMW has a relatively higher affinity for cadmium binding than that for nickel. Different multicomponent-isotherm models, extended Langmuir, modified Langmuir, extended Redlich-Peterson, and extended Sips isotherm models, were used to predict the removal of either ions using single metal isotherm data.

Keywords: Adsorption, Nickel, Cadmium, Heavy Metals, Manure, Isotherm, Activated Carbon, Removal, Biosorption, Copper, Sorbents, Water, Zinc, Ions

Kim, H.T., Lee, C.H., Shul, Y.G., Mon, J.K. and Lee, E.H. (2003), Evaluation of PAN-TiO₂ composite adsorbent for removal of Pb(II) ion in aqueous solution. Separation Science and Technology, 38 (3), 695-713.

Full Text: S\Sep Sci Tec38, 695.pdf

Abstract: A polyacrylonitrile-TiO₂ composite adsorbent bead was prepared to remove Pb²⁺ ion in aqueous solution. The dual nozzle technique was applied to prepare a spherical bead. The prepared composite adsorbent was found to be highly porous and stable against strong acids. Adsorption tests showed that Pb²⁺ ion adsorption increased in proportion to pH and Pb²⁺ ion was completely removed at pH 5.60. The equilibrium and kinetic parameters such as equilibrium constant, adsorption capacity, film mass-transfer coefficient, and effective diffusivity were also evaluated by modeling the experimental data.

Keywords: Mass-Transfer, Waste-Water, Lead, TiO₂, Polyacrylonitrile, Exchangers, Adsorption, Extraction, Sorption, Cadmium

Ottosen, L.M., Kristensen, I.V., Pedersen, A.J., Hansen, H.K., Villumsem, A. and Ribeiro, A.B. (2003), Electrodialytic removal of heavy metals from different solid waste products. Separation Science and Technology, 38 (6), 1269-1289.

Full Text: S\Sep Sci Tec38, 1269.pdf

Abstract: A variety of heavy metal polluted waste,products must be handled today. Electrochemical methods have been developed for remediation of polluted soil. One of the methods is the electrodialytic remediation method that is based on electromigration of heavy metal ions and ionic species within the soil matrix, land a separation of the soil and the process solutions, where the heavy metals are concentrated, with ion exchange membranes. For remediation of some soils, such as calcareous soils, it is necessary to add an enhancement solution. It was shown in a laboratory experiment that ammonium citrate could be used when removing Cu and Cr from a soil with 25% carbonates. The final concentrations of the elements were below the target values after the remediation. A question of whether the electrodialytic remediation method can be used for other waste products arose. Preliminary experiments showed that the method could be used for removal of different heavy metals from impregnated wood waste, fly ash from straw combustion, and fly ash from municipal solid waste incineration. The best result was obtained with the wood waste where more than 80% of each of the polluting elements Cu, Cr and As was removed in a 7-day experiment in which oxalic acid was used as enhancement solution. From the straw ash, 66% of the Cd was removed, but 64% of the fly ash dry mass dissolved during the treatment. In this actual experiment, no enhancement solution was used but that will be necessary to avoid dissolution of the ash to such a high extent. For the fly ash from waste incineration, ammonium citrate was tested as enhancement solution and in 14 days 62% Cd, 53% Cu, 6% Pb, and 31% Zn were removed. The preliminary results were thus promising for developing the electrodialytic method to other products than soil, although more research is needed especially in finding the best enhancement solutions for each product.

Keywords: Ash, Cd, Copper, Electrodialysis, Electrodialytic Remediation, Electrokinetic Remediation, Enhancement Solution, Fly Ash, Heavy Metal, Heavy Metal Ions, Heavy Metals, Heavy-Metal, Ion Exchange, Metal Ions, Metals, Oxalic Acid, Remediation, Soil, Solid Waste, Speciation, Waste, Wood

Zhang, A.Y., Uchiyama, G. and Asakura, T. (2003), The adsorption properties and kinetics of uranium(VI) with a novel fibrous and polymeric adsorbent containing amidoxime chelating functional group from seawater. Separation Science and Technology, 38 (8), 1829-1849.

Full Text: S\Sep Sci Tec38, 1829.pdf

Abstract: The adsorption properties of U(VI) with a new type of fibrous and polymeric adsorbent containing amidoxime chelating functional group (FPAO) from seawater was studied by the method of the static state adsorption at 25degreesC. The optimum conditions of the adsorption were determined by investigating the influence of the concentrations of FPAO, U(VI), feed acidity, temperature, and the shape and size of FPAO on the adsorption equilibrium. The maximum adsorption capacity of U(VI) in theory was deduced to be 384.6 mg/g dry FPAO by Langmuir isothermic adsorption equation. Freundlich isothermic adsorption equation, expressed as Q=4.116 [U(VI)](0.4293), shows that this process can taken place easily because the adsorption factor 1/n equals to 0.4293, which is in the region of 0.1-0.5. Meanwhile, the adsorption kinetics of U(VI) with FPAO was also studied. The rate equation of the adsorption reaction was determined as -d[U(VI)]/dt=k[U(V)IFPAO](1.70)/[H⁺] and the rate constant of the adsorption reaction k was calculated to be 0.5912 min^-1 for pH 6.0 and ionic strength 0.1 mol/l. The activation energy of the adsorption reaction was calculated to be 28.54 kJ/mol. On the basis of the kinetics results, the adsorption mechanism of FPAO on U(VI) was discussed. The diffusion of uranium ion in internal of the adsorbent was thought to be the rate-controlling step.

Keywords: Fibrous Adsorbent, Adsorption Properties and Kinetics, Amidoxime, Uranium, Seawater, Sea-Water, Recovery, UO₂²⁺

? Denizli, A., Yavuz, H., Arpa, C., Bektas, S. and Genc, O. (2003), Cysteinylhexapeptide attached poly(2-hydroxyethyl methacrylate) beads for Cd(II) removal from human plasma in a packed-bed column. Separation Science and Technology, 38 (8), 1869-1881.

Full Text: 2003\Sep Sci Tec38, 1869.pdf

Abstract: Poly(hydroxyethyl methacrylate) (PHEMA) beads (in the size range of 150-200 m) with good mechanical properties were prepared and crosslinked with ethylene glycol dimethacrylate (EGDMA) to increase their chemical stability. Because of their hydroxyl groups, they can serve as affinity adsorbent and can be employed for medical applications. Cibacron Blue F3GA was succesfully immobilized onto the beads. The maximum dye attachment was 16.5 mol/g. Then, metallopeptide-ligand cysteinylhexapeptide (CysHP) was incorporated onto these beads and they were used for removal of cadmium ions [Cd(II)] from human plasma in a packed-bed column. The maximum amount of CysHP attached was 3.2 mg/g. Non specific Cd(II) adsorption from human plasma on the PHEMA beads was 0.32 mg/g. The adsorption capacity of the beads decreased from 11.8 to 3.7 mg/g with the raise of the flow-rate from 1.0 to 5.0 ml/min. It has been found that the CysHP loading has a great effect on the capacity of beads for adsorbing Cd(II) ions from human plasma. This suggests that these modified beads could be used for removal of Cd(II) ions from human plasma.

Keywords: Adsorbent, Adsorption, Affinity, Affinity Beads, Cd(II) Removal, Chromatography, Cibacron Blue F3GA, Dye, Flow Rate, Ions, Metal Detoxification, Microspheres, Packed-Bed, Poly(2-Hydroxyethyl Methacrylate), Proteins, Purification, Removal

? Jia, Q., Wang, Z.H., Li, D.Q. and Niu, C.J. (2003), Adsorption studies of divalent metal ions with extraction resin containing 1-hexyl-4-ethyloctyl isopropylphosphonic acid. Separation Science and Technology, 38 (9), 2025-2037.

Full Text: 2003\Sep Sci Tec38, 2025.pdf

Abstract: Equilibrium distributions of cobalt(II), nickel(II), zinc(II), cadmium(II), and copper(II) have been studied in the adsorption with extraction resin containing 1-hexyl-4-ethyloctyl isopropylphosphonic acid (HEOPPA) as an extractant from chloride medium. The distribution coefficients are determined as a function of pH. The data are analyzed both graphically and numerically. The extraction of the metal ions can be explained assuming the formation of metal complexes in the resin phase with a general composition ML2(HL)(q). The adsorbed species of the metal ions are proposed to be ML2 and the equilibrium constants are calculated. The efficiency of the resin in the separation of the metal ions is provided according to the separation factors values. The separation of Zn from Ni, Cd, Cu, Co, and Co from Ni, Cd, Cu with the resin is determined to be available. Furthermore, Freundlich’s isothermal adsorption equations and thermodynamic quantities, i.e., G, H, and S are determined.

Keywords: 1-Hexyl4-Ethyloctyl Isopropylphosphonic Acid, Adsorption, Aqueous-Solutions, Cadmium(II), Cd, Chloride, Co, Cobalt(II), Composition, Copper(II), Cu, Cyanex-272, Data, Distribution, Divalent Metal Ions, Efficiency, Equilibrium, Extraction, Extraction Resin, Function, General, Impregnated Resins, Isothermal, Isothermal Adsorption, Levextrel Resin, Metal, Metal Complexes, Metal Ions, Nickel(II), Palladium(II), pH, Resin, Separation, Species, Thermodynamic, Zinc(II)

Say, R., Yilmaz, N. and Denizli, A. (2003), Biosorption of cadmium, lead, mercury, and arsenic ions by the fungus Penicillium Purpurogenum. Separation Science and Technology, 38 (9), 2039-2053.

Full Text: S\Sep Sci Tec38, 2039.pdf

Abstract: The potential use of the fungus Penicillium Purpurogenum to remove cadmium, lead, mercury, and arsenic ions from aqueous solutions was evaluated. Biosorption of heavy metal ions reached equilibrium in 4 h. Heavy metal ions binding by Penicillium Purpurogenum was clearly pH dependent. Heavy metal loading capacity increased with increasing pH under acidic conditions, presumably as a function of heavy metal speciation and due to the H⁺ competition at the same binding sites. The adsorption of heavy metal ions reached a plateau value at around pH 5.0. The maximum adsorption capacities of heavy metal ions onto the fungal biomass under noncompetitive conditions were 35.6 mg/g for As(III), 70.4 mg/g for Hg(II), 110.4 mg/g for Cd(II) and 252.8 mg/g for Pb(II). Their adsorption behavior can be described at least approximately with the Langmuir equation. The competitive adsorption capacities of the heavy metal ions were 3.4 mg/g for As(III), 15.8 mg/g for Hg(II), 13.1 mg/g for Cd(II), and 41.8 mg/g for Pb(II) at 50 mmol/L initial concentration of metal ions. The same affinity order on a molar basis was observed under noncompetitive and competitive adsorption conditions, which was as follows: Pb(II)>Cd(II)>Hg(II)>As(III). The equilibrium loading capacity of Pb(II) was greater than that of other metal ions. This fungal biomass showed a preference for binding Pb(II) over Cd(II), Hg(II), and As(III). Elution of heavy metal ions was performed using 0.5 M HCl. The fungus Penicillium Purpurogenum could be used for ten cycles for biosorption.

Keywords: Admium(II), Lead(II), Mercury(II), Arsenic(III), Heavy Metals, Fungal Biomass, Biosorption, Penicillium Purpurogenum, Phanerochaete-Chrysosporium, Heavy-Metals, Saccharomyces-cerevisiae, Aspergillus-niger, Rhizopus-arrhizus, Zoogloea-ramigera, Aqueous-Solution, Removal, Accumulation, Adsorption

Lazaridis, N.K., Jekel, M. and Zouboulis, A.I. (2003), Removal of Cr(VI), Mo(VI), and V(V) ions from single metal aqueous solutions by sorption or nanofiltration. Separation Science and Technology,