Hayrettin Eroglu

An environmentally friendly process; Adsorption of radionuclide Tl-201 on fibrous waste tea

This work presents an investigation of the adsorption of the radionuclide of Tl-201 from waste water on the fibrous tea factory waste. The experimental parameters were chosen as temperature, pH, stirring speed, adsorbent dose and nominal particle size in the ranges of 10.0-40.0 degrees C, 2.0-10.0, 300-720 rpm, 1.0-15.0 g/L and 0.15-0.71 mm, respectively. The most effective parameter on the adsorption yield was found to be pH of the solution. Fourier transforms infrared and electron paramagnetic resonance spectroscopy studies were performed for the characterisation of the adsorption on tea waste. The experimental data were found to be in good agreement with the isotherm models of Freundlich, Halsey, Handerson and Dubinin-Radushkevich. Thermodynamic analysis showed that the values of Delta G and Delta H are negative. It was obtained that the adsorption rate can be represented very well by second-order pseudo homogeneous kinetic model. All the results proved that fibrous tea plant waste makes an excellent adsorbent for Tl-201 radionuclide.

Biosorption of Ga-67 radionuclides from aqueous solutions onto waste pomace of an olive oil factory

The aim of this research was to test the removal of Ga-67 radionuclides from aqueous solutions by biosorption onto waste pomace of an olive oil factory (WPOOF). Batch adsorption studies were performed in order to investigate the temperature, the initial pH of the solution, the stirring speed, the biosorbent dose, and the nominal particle size of the biosorbent in the experimental work. The most effective parameter was found to be the initial pH. A high biosorption yield of 98 was obtained. The equilibrium values were fitted to the isotherm models. The values of DeltaG and DeltaH were calculated to be negative. The adsorption kinetics calculations showed that the kinetics of the biosorption process fitted well to the pseudo-second order rate model.

Bio-sorption of Tl-201 radionuclide on olive pomace

This work presents an investigation on the bio-sorption of Tl-201 radionuclide used in nuclear medicine on olive pomace. The experimental parameters were chosen as temperature, the initial pH of the solution, stirring speed, bio-sorbent dose and nominal particle size of bio-sorbent. The initial pH of the solution was found to be the most effective parameter. Thermodynamic analysis gave negative values for ΔG and ΔH. The kinetics of the bio-sorption process fitted very well to the pseudo-second order rate model.

Synthesis and Characterization of Nanofibres of 2ZnO·3B2O3·5H2O Ceramic Composite Using the Sol-Gel Processing and the Electrospinning Techniques

2ZnO.3B2O3.nH2O (Zinc borate) having the industrially important composite and used as flame retardant, anti-smoke and semiconductor in the electronic circuits was examined different crystal structures. In this study, nanofibers of PVA /zinc nitrate/ boric acid composite were prepared by using sol-gel processing and electrospinning technique. By high temperature calcinations of the above precursor fibers, nanofibers of 2ZnO.3B2O3.5H2O composite with diameters of 110 nm could be successfully obtained. The products have been characterized by X-ray powder diffraction (XRD), thermogravimetry (TG) and differential thermal analysis (DTA), scanning electron microscopy (SEM) and FT-IR (Fourier transform-infrared spectroscopy). The effects of experimental conditions on the products were investigated.