Ilkay Hilal Gubbuk

Isotherms and thermodynamics for the sorption of heavy metal ions onto functionalized sporopollenin

In this study, sporopollenin of Lycopodium clavatum spores was used for the sorption experiment. Glutaraldehyde (GA) immobilized sporopollenin (Sp), is employed as a sorbent in sorption of selected heavy metal ions. The sorbent prepared by sequential treatment of sporopollenin by silanazing compound and glutaraldehyde is suggested for sorption of Cu(II), Zn(II) and Co(II) from aqueous solutions. Experimental conditions for effective sorption of heavy metal ions were optimized with respect to different experimental parameters using batch method in detail. Optimum pH range of Cu(II) has occurred at pH≥5.5 and Zn(II), Co(II) at pH≥5.0, for the batch method. All of the metal ions can be desorbed with 10 cm(3) of 0.5 mol dm(-3) of ethylenediaminetetraacetic acid (EDTA) solution. Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherm equations were applied to the experimental data. Thermodynamic parameters such as free energy (ΔG(o)), entropy (ΔS(o)) and enthalpy (ΔH(o)) were also calculated from the sorption results used to explain the mechanism of the sorption. The results indicated that this sorbent is successfully employed in the separation of trace Cu(II), Zn(II) and Co(II) from the aqueous solutions.

Adsorptive removal of Co(II), Ni(II), and Cu(II) ions from aqueous media using chemically modified sporopollenin of Lycopodium clavatum as novel biosorbent

AbstractIn this study, sporopollenin of Lycopodium clavatum spores was used for sorption experiments. (E)-4-((2-hydroxyphenylimino) methyl) benzoic acid (HPBA) immobilized sporopollenin (Sp) was employed as a sorbent in sorption of selected heavy metal ions in aqueous solutions. The sorbent material was prepared with sequential treatment of sporopollenin with silanazing compound and HPBA. Experimental conditions for effective sorption of heavy metal ions were optimized with respect to different experimental parameters using the batch method in detail. pHs for maximum sorption of Cu(II) ≡ Ni(II) and Co(II) ions were found in six and five, respectively. Langmuir, Freundlich, and Dubinin–Radushkevich (D–R) isotherm equations were applied to the experimental data. Thermodynamic parameters such as free energy (ΔGo), entropy (ΔSo), and enthalpy (ΔHo) were also calculated from the sorption results and were used to explain the mechanism of the sorption. The results indicated that this sorbent is successfully empl...

Immobilization and characterization of hemoglobin on modified sporopollenin surfaces

Hemoglobin was covalently immobilized onto modified sporopollenin surface with different functional groups by chemical reactions to enhance binding ability of protein. In this study, the influence of various silane linker molecules on the capacity of protein binding was studied. For this purpose, activated sporopollenin was modified by 3-aminopropyltriethoxysilane (APTS), 3-chloropropyltrimethoxysilane (CPTS) and (3-glycidyloxypropyl)trimethoxysilane (GPTS). Hemoglobin (Hb) was immobilized on modified sporopollenin surfaces in phosphate buffer saline solution (PBS, pH 7.4) at 4°C. Results showed that GPTS modified sporopollenin surfaces resulted in the highest binding capacity for Hb. Micro porosity of samples was observed through scanning electron microscopy (SEM) and thermal behavior of the samples were studied with thermogravimetric analysis (TGA) within a temperature range: 25-900°C. TGA studies demonstrated the advantages of silane modification for high temperature applications and illustrated differences of the structures due to the different tail groups.

Preparation of calix[4]arene-based sporopollenin and examination of its dichromate sorption ability

The present study describes the preparation of a new calix[4]arene-based sporopollenin material and its application for the removal of Na2Cr2O7 from aqueous solution. The novel calix[4]arene-based sporopollenin material was prepared via the immobilization of dihydrazine amide derivative of p-tert-butylcalix[4]arene (3) onto the modified sporopollenin. The newly prepared calix[4]arene-based sporopollenin is characterized by using different analytical techniques such as FT-IR spectroscopy, scanning electron microscope and Elemental analysis. The batch wise sorption study was carried out to optimize various experimental parameters such as the effect of sorbent dosage, pH, temperature and Cr(VI) anion concentration. It has been found that the sorption of Cr(VI) anion on calix[4]arene-based sporopollenin was highly pH dependent and maximum sorption was achieved at pH 1.5. The sorption behavior was also evaluated by Langmuir, Freundlich and Dubinin Radushkevich isotherms. The value of correlation coefficient (R2) showed a good agreement with Freundlich isotherm model. Result of study demonstrated that calix[4]arene-based sporopollenin proved to be highly effective for the removal of Cr(VI).

Synthesis and Characterization of Sporopollenin-Supported Schiff Bases and Ruthenium(III) Sorption Studies

Two Schiff base derivatives, (2-pycolylimino)benzen-1,4-diol and (2-pyridylimino)benzen-1,4-diol) were immobilized onto sporopollenin (Lycopodium clavatum) surfaces. The compounds were fully characterized by an infrared spectroscopy, elemental analysis, scanning electron microscopy, and X-ray diffraction techniques. The sorption capacities of the immobilized surfaces toward Ru(III) ions were investigated by batch sorption experiments. For the sorption experiment, the Ru(III) concentration, initial pH, and the temperature effects were studied. The isotherm data of Ru(III) ions were correlated reasonably well as a Freundlich sorption isotherm. The thermodynamic studies showed that the Ru(III) sorption onto immobilized sporopollenin derivatives is a non-spontaneous, endothermic and physical reaction.

Synthesized of Sporopollenin-Immobilized Schiff Bases and Their Vanadium(IV) Sorption Studies

This study investigated the potential use of a biologic polymer Lycopodium clavatum spores (Sporopollenin) for removal of vanadium ions (V(IV)) from aqueous solution. Three Schiff base derivative compounds immobilized sporopollenin were prepared and characterized. Immobilized sporopollenin was characterized via a scanning electron microscope, elemental analysis, infrared spectroscopy and thermal analysis techniques. The sorption capacities of the immobilized surfaces toward V(IV) ions were investigated by batch sorption experiments. V(IV) concentration, initial pH and the temperature effects were studied. The isotherm data of V(IV) ions were correlated reasonably well both Langmuir, Freundlich sorption isotherm. The thermodynamic studies showed that the V(IV) sorption onto immobilized sporopollenin derivatives is a spontaneous, endothermic and a chemical reaction.

Preparation of polyaniline montmorillonite clay composites for the removal of diethyl hexyl phthalate from aqueous solutions

ABSTRACT The work presents the synthesis of polyaniline functionalized montmorillonite (PANI/MMT) clay composites and evaluation of their performance as an adsorbent for the mitigation of toxic diethyl hexyl phthalate (DEHP) from water. The formation of composite was confirmed by different analytical techniques such as FTIR, zeta potential analysis, XRD, SEM, and AFM. The adsorption capacity of PANI/MMT was superior to MMT. DEHP followed partition mechanism on PANI/MMT whereas MMT favored surface adsorption mechanism. The performance of PANI/MMT for DEHP removal was unaffected by the change in pH of solution, change in salinity, and hardness contents in aqueous system and consecutive adsorption desorption cycles compared to MMT. Furthermore, both PANI/MMT and MMT exhibited greater adsorption capacities as compared to the previously published work and showed satisfactory performance in real water samples.

Development of doxorubicin loading platform based albumin-sporopollenin as drug carrier

Albumin is thought as an drug carrier for doxorubicin (DOX). The binding of doxorubicin to albumin was studied on the surface of sporopolleninin (SP) to produce a new drug system based natural materials. Human serum albumin (HSA) was immobilized on SPIONs in 20 mM Tris buffer, 7.4 of pH. Data showed that binding amount of HSA has been found to be as 285.53 µg to the 25 mg of Sporopolleninin which also bounded 319.76 µM of DOX. Binding of protein and drug to Sp were clarified by SEM, EDX and FT-IR analysis.

Transport of methylene blue through bulk liquid membrane containing calix[8]arene derivative

AbstractIn this study, an experimental study on the transport of methylene blue (MB) through bulk liquid membrane (BLM) is done and thereby best set of solvent, operating conditions, and mode of transport that would yield optimum performance of the BLM are identified. Therefore, a kinetic study of MB transport from an aqueous donor phase into an aqueous acceptor phase through a BLM containing calix[8]arene octacarboxylic acid (COCA) derivative as a carrier was studied. The influence of type of solvent, stirring speed, effect of NaCl weight in feed phase and temperature were investigated. The kinetic parameters (k1, k2, , tmax, , ) were calculated for the interface reactions assuming two consecutive, irreversible first-order reactions. In this study, the experiments demonstrated that COCA derivative is a good carrier for MB transport through liquid membranes.

The Use of Voltammetry for Sorption Studies of Pb2+ from Aqueous Media using Schiff Base Immobilized Biologic Polymer Material

Adsorption by low-cost adsorbents and biosorbents is recognized as an effective and economic method for low-concentration heavy metal. The purpose of this study was to investigate the possibility of the utilization of N,N′-bis(2, 5-dihydroxybenzylidene)-1, 4-diaminobenzene (DHDB)-immobilized sporopollenin (Schiff base-immobilized sporopollenin, Sp-DHDB) as a sorbent for removal of lead (II) ion from aqueous solution. The effects of different parameters (such as sorbate concentration, sorbent dosage, and pH of the medium) were investigated by differential pulse anodic stripping voltammetry (DPASV) technique. The experimental data were analyzed by the Freundlich, Langmuir, and Dubinin–Radushkevich (D–R) isotherms. Equilibrium data fitted well with the Freundlich model and the procedure developed was successfully applied for the removal of lead ions in aqueous solutions. This investigation reveals a new, simple, environmentally friendly, and cost-effective method for the removal of lead ions from aqueous solutions by a new Sp-DHDB material.