Title: Turkderm-Archives of the Turkish Dermatology and Venerology

Title: Turkish Journal of Chemistry

ISO Abbreviated Title: Turk. J. Chem.

JCR Abbreviated Title: Turk J Chem

ISSN: 1010-7614

Issues/Year: 4

Journal Country/Territory: Turkey

Language: English

Publisher: Scientific Technical Research Council Turkey

Publisher Address: PO Box 605 Yenisehir, 06445 Ankara, Turkey

Subject Categories:

Chemistry: Impact Factor 0.145, 107/121

Engineering, Chemical: Impact Factor 0.145, 93/110

? İnel, O. (1995), Adsorption of ammonium ions and Methylene Blue dye by natural zeolite and effect of thermal treatment and acid activation on adsorption. Turkish Journal of Chemistry, 19 (4), 323-330.

Abstract: In this study, the utility of zeolitic tuffs obtained from the Bigadic (Balikesir) region was investigated as an ammonium ion exchanger and decolorizing agent. For this purpose the adsorptions of ammonium ions and Methylene Blue from aqueous solutions on the zeolitic tuffs were studied the batch equilibration technique as a function of adsorbate concentration. Adsorption isotherms were described using the Langmuir isotherm model. The effects of thermal treatments and acid activations on the adsorption capacity of tuffs were also examined.

Keywords: Acid, Acid Activation, Activation, Adsorption, Adsorption Capacity, Ammonium, Ammonium Ion, Capacity, Concentration, Dye, Effects, Function, Ion, Isotherm, Isotherms, Langmuir, Langmuir Isotherm, Methylene Blue, Model, Natural, Natural Zeolite, Thermal Treatment, Treatment, Utility, Zeolite

? Denizli, A., Piskin, E. and Salih, B. (1995), Metal chelate affinity chromatography: Congo Red and Cd(II) attached poly (EGDMA-HEMA) microbeads for specific albumin adsorption. Turkish Journal of Chemistry, 19 (4), 296-304.

Abstract: Poly (ethylene glycol dimethacrylate-2-hydroxyethyl methacrylate) microbeads, in the size range of 150-200 µm, were produced by a modified suspension copolymerization of the respective monomers, i.e., ethyleneglycoldimethacrylate (EGDMA) and 2-hydroxyethyl methacrylate (HEMA) in an aqueous media. Polyvinylalcohol and dibenzoyl peroxide were used as the stabilizer and the initiator, respectively. A diluent, namely toluene was included in the polymerization recipie. Congo Red was selected as a metal chelating ligand for specific adsorption of Cd(II) ions and was attached to poly (EGDMA-HEMA) microbeads by treating the dye and polymeric beads in an aqueous alkaline medium. Dye attached polymeric microbeads were characterized by optical microscopy, FTIR and elemental analysis. Adsorption of Cd(II) ions onto the Congo Red attached poly (EGDMA-HEMA) microbeads was investigated in the batch equilibrium experiments by using graphite furnace Atomic Absorption Spectrophotometer. Different amounts of Cd(II) ions (2-18.3 mgCd(II)/g polymer) were conjugated on the microbeads by changing the inital concentration of Cd(II) ions and pH. Bovine serum albumin (BSA) adsorption on these microbeads from aqueous solutions containing different amounts of BSA at different pH and ionic strengths was investigated in batch reactors. The nonspecific BSA adsorption on the poly (EGDMA-HEMA) microbeads was almost zero. Congo Red attachment significantly increased the BSA adsorption (up to 55.3 mgBSA/g polymer). A further increase in the adsorption capacity (up to 86.2 mgBSA/g polymer) was observed when Cd(II) ions were incorporated. More than 90% of the adsorbed BSA was desorbed in 1 h in the desorption medium containing 0.5 M NaSCN at pH 8.0.

Aksoylu, A.E., Akin, A.N., Sunol, S.G. and Onsan, Z.I. (1996), The effect of metal loading on the adsorption parameters of carbon dioxide on coprecipitated nickel-alumina catalysts. Turkish Journal of Chemistry, 20 (1), 88-94.

Full Text: T\Tur J Che20, 88.pdf

Abstract: A coprecipitation method has been developed and modified for the preparation of nickel-alumina catalysts having metal loadings in the 0-25 wt% Ni range. The effect of metal loading on CO₂ adsorption was investigated under isothermal chromatographic conditions using an elution technique in the temperature range 483-533 K. Average enthalpies of adsorption were determined using the isosteres obtained from the experimental adsorption isotherms. The isotherms were also fitted to the Langmuir equation for the evaluation of adsorption equilibrium coefficients, Gibbs free energies, average adsorption enthalpies and entropies.

Saraydin, D. and Karadağ, E. (1996), A comparison of adsorption isotherms of crosslinked poly(N-vinylpyrrolidone) Basic Brown 1 binding system. Turkish Journal of Chemistry, 20 (3), 234-243.

Full Text: T\Tur J Che20, 234.pdf

Abstract: In this study, the binding of a basic dye such as Basic Brown 1 [BB 1] onto a crosslinked poly(N-vinylpyrrolidone) [CPVP] was investigated. Adsorption of the azo dye onto the CPVP was studied by the batch adsorption technique at 25°C. In adsorption experiments a Langmuir type (L) adsorption was found with respect to the Giles classification system. Binding parameters such as initial binding constant (K_i), equilibrium constant (K), monolayer coverage (n), site-size (u), and maximum fractional occupancy (<(theta)over cap>), and thermodynamic parameters such as heat of adsorption (Delta H), free energy of adsorption (Delta G) and entropy of adsorption (Delta S) for the CPVP/BB 1 system were calculated by using Klotz, Scatchard, and Langmuir linearization methods.

Keywords: Crosslinked Poly(N-Vinylpyrrolidone), Basic Brown 1, Binding, Adsorption Isotherm, Hydrogels

İnel, O. and Aşkin, A. (1996), Adsorption of monovalent cationic dyes on some silicates. Turkish Journal of Chemistry, 20 (4), 276-282.

Full Text: T\Tur J Che20, 276.pdf

Abstract: Adsorption of two cationic dyes, Methylene blue (MB) and malachite green (MG), was studied on the bentonite, sepiolite and zeolite samples by the batch equilibration technique using a spectrophotometer. In addition, cation exchange capacities (CEC) of samples were determined by NH₄⁺ saturation using Kjeldhal distillation. The adsorption data was found to conform with the Langmuir equation within the concentration range studied, and Langmuir constants were determined for each of the samples. It was observed that the amount of dyes adsorbed was in excess of CEC in the case of bentonite and sepiolite. The adsorption capacities of the samples for both dyes have the following order: bentonite > sepiolite > zeolite.

Keywords: Crystal Violet, Methylene-Blue, Clay-Minerals, Montmorillonite, Surface, Absorption, Laponite, Exchange

Aydin, A.H., Güzel, F. and Tez, Z. (1996), Investigation of adsorption isotherms used for wool dyeing by aqueous extraction of cehri fruit (Fructus Rhamni Petiolari) and dyeing of wool and silk accompanied by various mordants. Turkish Journal of Chemistry, 20 (4), 283-288.

Full Text: T\Tur J Che20, 283.pdf

Abstract: In this study, adsorption isotherms were obtained by processing wool with dyestuff solutions of different concentrations extracted from cehri fruit with water. These isotherms follow the Nernst equation; the Nernst constant was determined and interpreted.

In addition, wool and silk fibres were dyed with the same dyestuff solution and various mordants. Colours having a high fastness which could be used on an industrial scale were produced.

Keywords: Dyestuff Adsorption, Natural Dyes, Dyeing Fibres, Cehri Fruit Extract, Wool Dyeing, Silk Dyeing

Topallar, H. (1998), The adsorption isotherms of the bleaching of sunflower-seed oil. Turkish Journal of Chemistry, 22 (2), 143-148.

Full Text: T\Tur J Che22, 143.pdf

Abstract: In this study, the absorbance measurements were taken for the bleaching of sunflower-seed oil with wt. 0.3, 0.5, 0.7 and 0.9 % of clay at 60, 70, 80 and 90°C. Bentonite EY-09 was used as the bleaching clay Since the heat evolved during adsorption (0.33-1.07 kJ mol^-1) was less than 20 kJ mol^-1, the forces between the adsorbent and adsorbate appear to be van der Waals forces, and this type of adsorption is physical or van der Waals adsorption. Thus, it was seen that the Freundlich equation was more applicable than the Langmuir equation to the experimental adsorption isotherms for the bleaching of sunflower-seed oil with Bentonite EY-09.

Keywords: Adsorption Isotherm, Bleaching, Freundlich Equation, Langmuir Equation, Sunflower-Seed Oil

Karadağ, E., Saraydin, D. and Aydin, F. (1998), Removal of water-soluble cationic dyes with TriSyl silicas. Turkish Journal of Chemistry, 22 (3), 227-236.

Full Text: T\Tur J Che22, 227.pdf

Abstract: In this study, the adsorption of certain water-soluble cationic dyes, (basic blue 9, basic blue 12, basic blue 17, brilliant cresyl blue, janus green B, basic green 4, basic violet 1, basic violet 3, and thionin) onto TriSyl silicas by batch adsorption at 25°C was investigated. In the adsorption experiments, Langmuir type adsorption in the Giles classification system was found. Binding parameters such as the initial binding constant (K_i), the equilibrium binding constant (K), monolayer coverage (n), site-size (u), maximum fractional occupancy (< (theta)over cap>), and the thermodynamic parameter free energy of adsorption (Delta G) were calculated for TriSyl silica and cationic dye systems by using the linearization methods of Klotz and Langmuir.

Keywords: Acrylamide/Itaconic Acid Hydrogels, Solute Adsorption-Isotherm, Aqueous-Solutions, General Treatment, Binding, Classification, Behaviors, Trisyl Silicas, Cationic Dyes, Binding, Adsorption

İnel, O., Albayrak, F. and Aşkin, A. (1998), Cu and Pb adsorption on some bentonitic clays. Turkish Journal of Chemistry, 22 (3), 243-252.

Full Text: T\Tur J Che22, 243.pdf

Abstract: Cu²⁺ and Pb²⁺ adsorption isotherms were measured on some clay samples obtained from various regions of Turkey. Also specific surface areas of clays were determined from adsorption data of ortho-phenanthroline(OP). The adsorptions of ions and OP were studied using the batch equilibration technique as a function of adsorbate concentration. The adsorption data, over the whole range of concentrations used, follow the Langmuir adsorption isotherm. The retention capacities of the adsorbates and the cation exchange capacities of the clays were determined. Plots of K_d, the distribution coefficient of ions between the solid and solution phases, vs, Gamma, the surface density of adsorbed ions, showed that all the samples behave similarly: i.e. K_d sharply decreases with increasing values of Gamma. The amount of Pb²⁺ adsorbed is about 3-4 times that of Cu²⁺ and the same adsorption capacity sequence was found for each ion.

Keywords: Sorption, Soils, Montmorillonite, Cadmium, Zinc, Cd

Akçay, G. and Yurdakoç, M.K. (1999), Nonyl- and dodecylamines intercalated bentonite and illite from Turkey. Turkish Journal of Chemistry, 23 (1), 105-113.

Full Text: T\Tur J Che23, 105.pdf

Abstract: Bentonite and illite were interacted with nonyl- and dodecylammonium salt solutions to see how the alkylammonium ions became attached and oriented within the interlamellar space of the clays. X-ray diffraction analyses were carried out to obtain information on the interlamellar organization and orientation of the adsorbed alkylammonium compounds. Thermogravimetric analysis (TG, DTG) and Fourier Transform Infrared Analyses (FTIR) were performed to characterize the samples and to determine the amounts adsorbed by the clay samples. The modification process was effective in nonyl- and dodecylammonium bentonites. Alkylammonium ions were adsorbed in the interlamellar space of the clays. Regarding the orientation of the alkylammonium ions between the silicate sheets, it was found that the organic cation alkylchains were parallel to the silicate layer. Intercalation was generally greater with DA ions.

Teker, M., İmamoğlu, M. and Saltabaş, Ö. (1999), Adsorption of copper and cadmium ions by activated carbon from rice hulls. Turkish Journal of Chemistry, 23 (2), 185-191.

Full Text: T\Tur J Che23, 185.pdf

Abstract: The removal of copper(II) and Cadmium(II) ions from aqueous solutions, by adsorption on activated carbon prepared from rice hulls (ACRH); was investigated depending on pH, activated carbon dosage, contact time, initial metal concentration and solution temperature. The optimum values of pH, ACRH dosage and contact time were determined to be 5-8, 0.5 g ACRH/25 mt solution an 60 minutes respectively for the adsorption of Cu(II) ions and 5-8, 1.5 g ACRH/25 mt solution and 60 minutes for the adsorption of Cd(II) ions. From the initial concentrations, the constants for the Freundlich and Langmuir isotherm were calculated at 293 K and 313 K. The adsorption of Cu(II) and Cd(II) ions from aqueous solutions was found to be exothermic [H° = -13.474 KJ/mol for Cu(II) and H° =-2.302 KJ/mol for Cd(II)]. Furthermore, the other thermodynamic data for G° and S°, were also calculated at 293 K and 313 K.

Keywords: Fly-Ash, Adsorption, Heavy Metal, Activated Carbon, Rice Hulls

Topallar, H. and Bayrak, Y. (1999), Investigation of adsorption isotherms of myristic, palmitic and stearic acids on rice hull ash. Turkish Journal of Chemistry, 23 (2), 193-198.

Full Text: T\Tur J Che23, 193.pdf

Abstract: The adsorption of myristic, palmitic and stearic acids on rice hull ash from isooctane as solvent was studied and conformed to a Langmuir isotherm. Monolayer coverage was determined to be 40.08, 38.43 and 37.27 mg/g, respectively. The free energy of adsorption, Delta G(ads)(o), for the adsorption was determined to be -6, 25, -6.32 and -6.39 kcal mol^-1 for the adsorbates, respectively. The equilibrium parameter indicated that rice hull ash is a good adsorbent for myristic, palmitic and stearic acids examined.

Keywords: Adsorption, Free Energy of Adsorption, Langmuir Isotherm, Myristic, Palmitic, Stearic Acids, Rice Hull Ash, Fatty-Acids, Oil

İnel, O. and Tümsek, F. (2000), The measurement of surface areas of some silicates by solution adsorption. Turkish Journal of Chemistry, 24 (1), 9-19.

Full Text: T\Tur J Che24, 9.pdf

Abstract: In this study, the adsorption from solution technique was used for the determination of surface areas of some silicate samples (bentonite, sepiolite, zeolitic tuff and kaolin). Methylene blue (MB), orthophenanthroline (OP) and p-nitrophenol (PNP) were selected as solutes.

The adsorption data was found to conform with the Langmuir equation within the concentration range studied, and Langmuir constants were determined for each of the samples.

The surface area values obtained were compared with those determined by nitrogen adsorption. Also the results were discussed with respect to the cation exchange capacities of the samples.

The specific surface area values of the samples were found to decrease in the following order:

Bentonite > Sepiolite > Zeolite > Kaolin (for MB and OP adsorption)

Sepiolite > Bentonite > Zeolite > Kaolin (for PNP and N-2 adsorption).

Keywords: Surface Area Determination, Solute Adsorption, Adsorption From Solution, Methylene-Blue, Cation-Exchange, Montmorillonite, Clays

Aktaş, Z. (2000), Effect of non-ionic reagent adsorption on zeta potential of fine coal particles. Turkish Journal of Chemistry, 24 (2), 117-129.

Full Text: T\Tur J Che24, 117.pdf

Abstract: The -5 m size fractions of two low rank British coals were used in zeta potential measurements. The electrophoretic behaviour was described by the Helmholta-Smoluchowski equation. The non-ionic reagents used for the adsorption tests were of diacetone alcohol and 2-ethylhexanol. Zeta potentials of both coals at various pHs were significantly different in the absence of the non-ionic reagents. Negligible variations were observed on the zeta potential curves of both coal particles in the presence of the non-ionic reagents used. It was concluded that the pH of coal particles in slurry is a principle parameter controlling the value of zeta potentials. As the zeta potential for Bickershaw coal particles was zero at about pH 5, the point of zero zeta potential was not observed for Rawdon coal particles. This is attributed to the functionality and the extent of oxidation of the coal surface.

Keywords: Zeta Potential, Non-Ionic Reagents, Coal, Rank British Coals, Flotation, Homologs

Arpa, Ç., Say, R., Şatiroğlu, N., Bektaş, S., Yürüm, Y. and Genç, Ö. (2000), Heavy metal removal from aquatic systems by northern Anatolian smectites. Turkish Journal of Chemistry, 24 (2), 209-215.

Full Text: T\Tur J Che24, 209.pdf

Abstract: Competitive adsorption of the heavy metal ions Cu(II), Cd(II) and Pb(II) from aqueous media onto northern Anatolian smectites with a mean particle diameter of 200 m, was investigated. The adsorption rate and capacity of the smectite for the selected heavy metal ions, containing different amounts of these ions (5-900 mg/L) at values ranging from pH 1.0 to 7.0 were studied. Very high adsorptions rates were observed at the beginning, and adsorption equilibria were then gradually achieved in about 30 minutes. The maximum adsorption of metal ions onto the smectite were found to be 41.46 mg Cd(II), 36.11 mg Pb(II) and 18.72 mg Cu(II) per gram of smectite. The order of affinity based on weight uptake by smectite was Cd(II)>Pb(II)>Cu(II). When the metal ions competed (in the case of adsorption from their mixture), the amounts of Cd(II), Pb(II) and Cu(II) ions adsorbed were 11.86 mg, 11.23 mg and 16.76 mg per gram of smectite, respectively Desorption of the metal ions from smectite was studied in 0.5 M HNO₃ and very high desorption rates, greater than 95%, were achieved in all cases.

Keywords: Attached Poly(Egdma-Hema) Microbeads, Cadmium, Ions, Adsorption, Microspheres

Uzun, İ. and Güzel, F. (2000), Adsorption of some heavy metal ions from aqueous solution by activated carbon and comparison of percent adsorption results of activated carbon with those of some other adsorbents. Turkish Journal of Chemistry, 24 (3), 291-297.

Full Text: T\Tur J Che24, 291.pdf

Abstract: In this study, removal of some heavy metals ions (Mn²⁺, Fe²⁺, Ni²⁺ and Cu²⁺) from aqueous solution by adsorption was investigated. For this purpose, high-grade MnSO₄.H₂O, FeSO₄. 7H₂O, NiSO₄. 7H₂O and CuSO₄. 5H₂O were used as heavy metal samples. The commercial activated carbon (Merck 2514), chitosan and agar were used as adsorbents. The pH of each solution was not controlled. This is because the net interaction between the adsorbent and the heavy metal could be disturbed by the buffer solution. Therefore, all experiments were carried out in a pH range from 5.3 to 5.5. The equilibrium adsorption contact times were determined for M - 2514. The adsorption rate constants were determined from obtained kinetics curves suitable for first degree of rate kinetics. Adsorption isotherms of heavy metals on M - 2514 from aqueous solution were determined. These adsorption isotherms were seen to be consistent with Freundlich’s adsorption isotherm. k and n constants were determined from Freundlich’s linear equation. In addition, M - 2514, chitosan and agar were compared according to their percent uptake yields of the heavy metals.

Keywords: Heavy Metal Adsorption, Activated Carbon, Chitosan, Agar, Adsorption From Aqueous Solution, Adsorption Kinetics, Adsorption Isotherm, Swollen Chitosan Beads, Chemically-Modified Chitosan, Acid

Tokalioğlu, Ş., Şahin, U. and Kartal, Ş. (2001), Determination of fluoride and some metal ion levels in the drinking waters in Kayseri province. Turkish Journal of Chemistry, 25 (1), 113-121.

Full Text: T\Tur J Che25, 113.pdf

Abstract: Fluorine is one of the most common elements in the Earth’s crust. Fluoride is recognized to be the most effective caries-preventive agent. The main sources of fluoride for people are generally food and drinking water. For this reason, the fluoride and also the metal ion (Ca. Cr, Cu, Fe, K. Mg. Mn, Na, Ni, Pb and Zn) concentrations in the drinking waters collected from the city center of Kayseri and its counties were investigated. In the determination of fluoride and of Na and It. an ion-meter with a combination-fluoride electrode and a flame photometer were used, respectively. The levels of Cr, Cu, Fe, Mn, Ni and Pb in the drinking waters were determined bq flame atomic absorption spectrometry (FAAS) utilizing the method optimized previously, except for the Ca, Mg and Zn contents, which were measured directly by FAAS. According to the results obtained, the metal ion concentrations in the drinking waters in the studied area are within the safe drinking water regulation limits (TS 266) and also the fluoride levels las mean 0.17 mg L^-1) are lower than the permissible limit for fluoride (0.8-1.7 mg L^-1).

Keywords: Fluoride, Metal Ions, Drinking Water, Preconcentration, Atomic Absorption Spectrometry, Atomic-Absorption Spectrometry, Trace Amounts, Zinc Metal, Preconcentration, Cadmium, Samples, Alumina, Copper, Resin, Lead

Ceyhan, Ö. and Baybas, D. (2001), Adsorption of some textile dyes by hexadecyltrimethylammonium bentonite. Turkish Journal of Chemistry, 25 (2), 193-200.

Full Text: T\Tur J Che25, 193.pdf

Abstract: In this study, hexadecyltrimethylammonium (HDTMA) bentonite was synthesized by placing alkylammonium cation onto bentonite. Adsorption of some textile dyes such as Everdirect Supra Yellow PG, Everdirect Supra Orange 26 CG, Everdirect Supra Rubine BL, Everdirect Supra Blue 4BL and Everdirect Supra Red BWS on Na-bentonite and HDTMA-bentonite was investigated. While the Na-bentonite had no affinity for the dyes, the HDTMA-bentonite showed significant adsorption from aqueous solution. The Langmuir and Dubinin-Rasdushkevich (D-R) isotherm equations were applied to the data and values of parameters of these isotherm equations were evaluated. The mean energy of adsorption, E, was also calculated from the adsorption energy constant K’ values determined from the D-R isotherm equation.

Keywords: Organoclay, Textile Dyes, Adsorption Isotherms, Langmuir Equation, Dubinin-Rasdushkevich (D-R) Equation, Sorption, Clay, Water, Adsorbent, Smectite

Qadeer, R. and Rehan, A.H. (2002), A study of the adsorption of phenol by activated carbon from aqueous solutions. Turkish Journal of Chemistry, 26 (3), 357-361.

Full Text: T\Tur J Che26, 357.pdf

Abstract: A commercial active carbon was tested as an adsorbent for the removal of phenol from aqueous solutions. The optimum conditions for maximum adsorption in terms of shaking time. amount of the adsorbent. and concentration of the adsorbate were identified. The adsorption data Fitted the Langmuir isotherm equation in the whole range of concentrations studied. The adsorption of picric acid, pyrogallol and salicylic acid at selected conditions for phenol was also studied. Elution studies to recover the adsorbed phenol from active carbon were performed with distilled water. NaOH and HCl solutions.

Keywords: Phenol, Active Carbon, Adsorption and Aqueous Solutions, Charcoal

Güzel, F. and Uzun, İ. (2002), Determination of the micropore structures of activated carbons by adsorption of various dyestuffs from aqueous solution. Turkish Journal of Chemistry, 26 (3), 369-377.

Full Text: T\Tur J Che26, 369.pdf

Abstract: In this study, some activated carbons prepared from sour cherry pits under various conditions were investigated, For comparison purposes, the commercial activated carbons Merck-2514 and Merck-2184 were used. The nitrogen adsorption isotherms at 77 K were used as reference for comparison. while p-nitrophenol, methylene blue, orange-II and victoria blue adsorptions were determined from aqueous solution at 298 K. It was clear from the specific surface area values obtained that the bust activated carbon was obtained by activation for 4 hours following the chemical activation. Its adsorption properties are closer to the levels of the Merck commercial carbons. It was concluded that the characterization of microporous structure, and the testing of the removal of organic impurities from aqueous solution for active carbons having high adsorption ability from the gas phase, can generally be carried out by adsorption of organic solutes whose molecular sizes are smaller than the micropore size (1.5 nm) of the adsorbent.

Keywords: Activated Carbon, Analysis of Pore Structure, Dyestuff Adsorption, N₂ Adsorption

Yalçinkaya, Y., Arıca, M.Y., Soysal, L., Denizli, A., Genç, O. and Bektaş, S. (2002), Cadmium and mercury uptake by immobilized Pleurotus sapidus. Turkish Journal of Chemistry, 26 (3), 441-452.

Full Text: T\Tur J Che26, 441.pdf

Abstract: Pleurotus sapidus basidiospores immobilized onto Ca-alginate beads were used for the removal of cadmium and mercury ions from aqueous solutions. The biosorption of Cd(II) and Hg(II) ions on the alginate beads and both immobilized live and heat inactivated fungal mycelia of Pleurotus sapidus was studied from aqueous solutions in the concentration range of 30-500 mg L^-1. The biosorption of Cd(II) and Hg(II) ions by the alginate and both live and heat inactivated immobilized preparations increased as the initial concentration of the ions increased in the medium. Maximum biosorption capacity for immobilized live and heat inactivated fungal mycelia of Pleurotus sapidus was found to be 96.57 mg g^-1 (0.86 mmol g^-1) and 127.12 mg g^-1 (1.13 mmol g^-1) for Cd(II) and 207.89 mg g^-1 (1.04 mmol g^-1) and 287.43 mg g^-1 (1.43 mmol g^-1) for Hg(II), respectively. The electronegativities and standard electrode potentials of the divalent ions of Group II elements show a definite trend with sorption capacity. Biosorption equilibria were established in about I h and were very well described by Langmuir isotherms. The temperature change between 1.5 and 4.5degreesC did not affect the biosorption capacity. The effect of pH was also investigated and the maximum uptake of metal ions on the alginate and both live and inactivated immobilized fungal mycelia were observed between pH 3.0 and 7.0. The alginate-fun.-us beads were regenerated using 10 mM HCl, with up to 97% recovery, the biosorbents were reused in three biosorption-desorption cycles without any considerable loss in the biosorption capacity.

Keywords: Heavy-Metal Biosorption, Adsorption, Alginate, Ions, Removal, Biotechnology, Exchange, Sorbents, Biomass, Algae

Akarsu, M., Sayilkan, H., Şener, A., Sayilkan, F. and Arpaç, E. (2003), Synthesis, characterization and applications of sol-gel derived zirconium oxide adsorbent powder: Removal from aqueous solution of phenol and p-chlorophenol. Turkish Journal of Chemistry, 27 (4), 477-486.

Full Text: T\Tur J Che27, 477.pdf

Abstract: Adsorbent powders were prepared from the uncatalysed hydrolysis-condensation reactions of different complexes that were synthesized by the reactions of Zr(OPrn)₄ with different chelating ligands (such as allylacetic acid [AAH], vinylacetic acid [VAH] and citraconic acid [CAH]). The complex products were characterized by FT-IR, H-1-NMR and C-13-NMR spectra. The maximum combination ratios of AAH/Zr(OPrn)₄, VAH/Zr(OPrn)₄ and CAH/Zr(OPrn)₄ were 1.7, 0.9 and 1.3, respectively. The hydrolysis-condensation products of these complexes were calcinated at 900 degreesC and half of them were coated with 3-glycidyloxypropyltrimethoxysilane (GLYMO). The surface area and average pore diameter of the powders were estimated by the analysis of adsorption/desorption BET isotherm data. The adsorption capacities of these powders for aqueous phenol and p-chlorophenol were calculated following spectrophotometric determination. Phenol and p-chlorophenol adsorption on all of the GLYMO-coated adsorbents were satisfactory, e.g., the adsorbent obtained from the hydrolyzed, calcinated and GLYMO-coated form of Zr(OPrn)(2.3)(AA)(1.7) adsorbed 63% of phenol while the uncoated form adsorbed only 10%. The adsorption isotherm has been determined and data have been analyzed according to the Freundlich model.

Keywords: Adsorbent, Adsorption, Coating Sol-Gel Process, Zirconium Idkoxides, Hydrolysis-Condensation Reactions, Activated Carbon, Adsorption, Products, Montmorillonite, Equilibrium, Alkoxides, Films, Dyes

Begum, S. (2003), Silver removal from ware by adsorption on concrete particles. Turkish Journal of Chemistry, 27 (5), 609-617.

Full Text: T\Tur J Che27, 609.pdf

Abstract: The ability of concrete to remove silver from its aqueous solutions was studied. Silver removal is favored by low concentration and high pH at room temperature. The intrinsic acidity constants, average pKint a1 and average pK_int a2 were determined. The calculated pH_PZC (5.4) is in agreement with the pH_PZC values determined from zeta potential measurements, indicating that the concrete particulate behaves amphoterically.

The total acidity capacity for the negative and positive surface was 0.5(cm²)/(muC). A surface complex. 2 formation model (SCFM) was used to describe the adsorption of silver onto concrete particles. In general the equilibrium constants, the pK(i)S values, decrease as the silver loadings increase.

Keywords: concrete, equilibrium constants, intrinsic acidity constants, silver adsorption, surface acidity.

Chmielewská, E. (2003), Adsorption of arsenate and chromate from waters on hydrophobized zeolitic media. Turkish Journal of Chemistry, 27 (5), 639-648.

Full Text: T\Tur J Che27, 639.pdf

Abstract: A laboratory setup was used to examine the uptake of chromate and arsenate from aqueous solutions by octadecylammonium acetate [ODA]-modified inland clinoptilolite. In trials, a natural variety of montmorillonite was compared to organic, i.e. surfactant loaded clinoptilolite. and some inorganically substituted (Ag, Pb) monoforms. The arrangement of the surface-attached ODA chains was the important factor for differences in the adsorption states of the guest species (oxyanions). A novel nanostructure inorganic-organic composite was prepared and was characterized by SEM, thermogravimetry, HR TEM, UV-VIS diffuse reflectance and powder XRD spectral analytical methods. Finally, the adsorption isotherms of the studied system were expressed. An approach was proposed for the regeneration of exhausted surfactant-immobilized clinoptilolite with inorganic salt solutions under a dynamic regime.

Keywords: Octadecylammonium-Clinoptilolite, Adsorption, Anion-Exchange, Chromate and Arsenate Oxyanions, Montmorillonite

Sayilkan, F., Sayilkan, H., Erdemoğlu, S., Şener, Ş. and Akarsu, M. (2004), New adsorbents from Ti(OPrⁿ)₄ by the sol-gel process: Synthesis, characterization and application for removing some heavy metal ions from aqueous solution. Turkish Journal of Chemistry, 28 (1), 27-38.

Full Text: T\Tur J Che28, 27.pdf

Abstract: New adsorbents were synthesized by the sol-gel process from the product of a hydrolysis reaction and its coated form of titanium(IV)-n-propoxide for removing some heavy metal ions from aqueous solution. Titanium(IV)-n-propoxide was uncatalyst hydrolyzed with different amounts of water at room temperature and was found to react in a 1:1.6 ratio (mole of Ti:mole of H₂O). It was found that the condensation following the hydrolysis reflection was alcohol condensation. The hydrolysis-condensation product was characterized in detail by GC. Karl-Fischer coulometric titrator, NIR-spectroscopy, FT-IR spectroscopy, TG-DTA and elemental analysis. The hydrolysis-condensation product of titanium(TV)-n-propoxide was calcinated at 900degreesC after drying at 100degreesC and some of this product was coated with hydrolyzed NH₂-functional silanes [3-(2-aminoethylamino)ethylamino)propyl-trimethoxy silane] (Amino-and [3-(2-aminoethylamino)propylmethyldimetoxysilane] (Amino-2), separately. Adsorption capacities of uncoated and NH₂-functional silane coated hydrolysis-condensation products for Fe³⁺, Cu²⁺ and Pb²⁺ ions in aqueous solution were investigated by FAAS. It was observed that the extent of adsorption was influenced significantly by the type and concentrations of coating materials, e.g., Amino-1 coated adsorbent prepared in methyl alcohol as 50% (w/w) and 100% (without methyl alcohol) adsorbed 90-67% and 100% of Fe³⁺, respectively. while the uncoated form adsorbed only 5%. The adsorption isotherm was determined and the data were analyzed according to the Freundlich model.

Keywords: Sol-Gel Process, Adsorption, Adsorbent, Waste Water, Heavy Metals, Coating, Adsorption, Water, Waste, Acid, Lead

Uzun, İ. and Güzel, F. (2004), External mass transfer studies during the adsorptions of some dyestuffs and p-nitrophenol onto chitosan from aqueous solution. Turkish Journal of Chemistry, 28 (6), 731-740.

Full Text: T\Tur J Che28, 731.pdf

Abstract: The effect of temperature on the adsorptions of some dyestuffs [orange II (O-II), crystal violet (CV) and reactive blue 5 (RB5)] and an ideal adsorbate p-nitrophenol (PNP) by chitosan (Sigma C 3646) from aqueous solution was investigated. The experimental data related to adsorption isotherms were applied to linear forms of the equations that they fitted, and isotherm constants were calculated. Since the isotherm curves obtained for the adsorptions of O-II and CV by chitosan fitted the Langmuir adsorption isotherm, the Langmuir constants (qm and b) related to the adsorption isotherms of these dyestuffs together with their kinetical data at different temperatures were applied to the equation of McKay et al., and external mass transfer coeffcients (kf)1 at these temperatures were calculated. In addition, kinetic data obtained for each dyestuff and PNP at different temperatures were applied to a further equation developed by Weber-Mathews, and (k_f)2 constants at these temperatures were calculated.

Keywords: Chitosan, Dyestuff Adsorption, External Mass Transfer Coeffcient

? Şahin, E. (2005), Interpretation of sorption kinetics for mixtures of reactive dyes on wool. Turkish Journal of Chemistry, 29 (6), 617-625.

Full Text: 2005\Tur J Che29, 617.pdf

Abstract: The equilibrium sorption isotherms of 3 reactive dyes (C. I. Reactive Yellow 84, C. I. Reactive Red 141, C. I. Reactive Blue 160) and their binary mixtures adsorbed on prewetted wool fiber were investigated. The kinetic studies were carried out at pH <= 7 and 80°C in dye solutions containing 20 g/L NaCl. It was reported that binary mixtures of these reactive dyes have lower sorption values than the dyes alone, at the same dye concentration, pH and temperature. The isotherms obtained are Langmuir type. The rate parameters of adsorption kinetics decrease with increasing dye concentration.

Keywords: Adsorption, Adsorption Kinetics, Cotton, Dye, Dye Adsorption, Dyeing Systems, Dyes, Equilibrium, Isotherms, Kinetic, Kinetic Model, Kinetics, Langmuir, Nylon, Part 1, pH, Reactive Dye, Reactive Dyes, Solutions, Sorption, Sorption Kinetics, Temperature

? Jayswal, A. and Chudasama, U. (2008), Synthesis and characterization of a novel metal phosphonate, zirconium(IV)-hydroxy ethylidene diphosphonate, and its application as an ion exchanger. Turkish Journal of Chemistry, 32 (1), 63-74.

Full Text: 2008\Tur J Che32, 63.pdf

Abstract: A novel hybrid ion exchange material, Zirconium-hydroxy ethylidene diphosphonate [ZrHEDP], of the class of tetravalent metal acid (TMA) salts has been synthesized by the sol-gel technique. The material was characterized with elemental analysis (ICP-AES), thermal analysis (TGA, DSC), and FT-IR and Xray diffraction studies. The chemical resistivity of the material in various media was evaluated. ZrHEDP was further investigated for its possible use as an ion exchanger. The Na+ ion-exchange capacity (IEC) of the material was determined, and kinetics and thermodynamics of exchange for the metal ions Cu(II), Ni(II), Zn(II), and Mn(II) towards ZrHEDP were studied. The sorption of the metal ions follow the order Zn(II) > Cu(II) > Mn(II) approximate to Ni(II).

Keywords: Inorganic Ion Exchanger, Metal Phosphonate, Tetravalent Metal Acid Salt, Zirconium-Hydroxy Ethylidene Diphosphonate, Zr(IV) Phosphonate, Aqueous-Solution, Chemistry, Sorption, Removal, Temperature, Adsorption, Arsenate, Copper