Browsing by Author "Erol, Kadir"

Now showing 1 - 4 of 4

Magnetic diatomite for pesticide removal from aqueous solution via hydrophobic interactions
(Springer Link, 2019) Alacabey, İhsan; Yıldız, Emrecan; Alacabey, İhsan; Karabörk, Muharrem; Uzun, Lokman
Pesticides are highly hazardous chemicals for the environment and human health and their use in agriculture is constantly increasing. Although 1,1,1-trichloro-2,2-bis(4-chlorophenyl) ethane 4,4′-DDT was banned at developed countries, it is still one of the most dangerous of chemical due to accumulation in the environment. It is known that the toxicity of DDT affects some enzyme systems biochemically. The main motivation of this study is to develop an effective adsorbate for the removal DDT, which was chosen as a model hydrophobic pesticide, out of aqueous systems. For this purpose, the bare diatomite particles were magnetically modified and a hydrophobic ligand attached to enhance its adsorptive and physio-chemical features. Under optimal conditions, a high adsorption capacity, around 120 mg/g with the hydrophobic and magnetic diatomite particles, modification of the diatomite particles reduced average pores diameter whereas surface area and total pore volume increased (around 15-folds). After five consecutive adsorption–desorption cycles, no significant decrease in adsorption capability was observed. The adsorption isotherms (Langmuir, Freundlich, and Flory–Huggins) applied to the data indicated that the adsorption process occurred via monolayer adsorption in an entropy-driven manner. The kinetic data also revealed the quick adsorption process without any diffusion limitations
Preconcentration and Determination of Cu(ii) and Cd(ii) Ions From Wastewaters by Using Hazelnut Shell Biosorbent Immobilized on Amberlite Xad-4 Resin
(2023) Alacabey, İhsan; Erol, Kadir; Teğin, İbrahim; Akdeniz, Selma; Acar, Orhan
Hazelnut shell biosorbent immobilized on Amberlite XAD-4 polymer resin as solid phase extraction method was developed and used for preconcentration of Cu(II) and Cd(II) ions from aqueous solutions. Concentrations of analytes in solutions were determined by Flame Atomic Absorption Spectrometry after extraction with column technique. Functional groups of nutshell biosorbent immobilized on resin were characterized by Fourier transform infrared spectrometry. Optimized critical parameters for preconcentration of Cu2+ and Cd2+ ions from sample solutions with nutshell immobilized on the resin were the pH value of solution, type of eluent solutions, the flow rate of sample solution, quantities of nutshell biosorbent, Amberlite XAD-4 resin, and enrichment factors, respectively. Detection limits of Cu2+ and Cd2+ ions found were 0.29 μg L-1 and 0.25 μg L-1, respectively. The method proposed was applied for determinations of Cu2+ and Cd2+ ions in standard reference material (BCR-670 aquatic plant sample) for accuracy and applied to real water samples such as wastewater and Van lake water. At the 95% confidence level, relative standard deviations (RSDs) were found as 1.44% for Cd2+ and 1.21% for Cu2+ ions with three replicate measurements.
Reactive Blue 19 Adsorption on Activated Carbon from Pumpkin (Cucurbita Pepo) Seed Waste: Kinetic, Isotherm and Thermodynamic Studies
(Kauno Technologijos Universitetas, 2024) Alacabey, İhsan; Benek, Veysel; Teğin, İbrahim; Önal, Yunus; Erol, Kadir; Alacabey, İhsan
In this study, the removal of reactive blue 19 dyestuffs in aqueous systems was investigated by the adsorption method using activated carbon obtained from pumpkin seed waste. Activated carbon obtained from pumpkin seed waste functionalized with ZnCl2 was used as an absorbent. Pumpkin seed hydrochar was characterized by FT-IR, SEM, TGA-DTA, BET, and XPS. In the experimental stages, the adsorption equilibrium time was determined as 45 minutes, the adsorbent dosage was 0.8 g and the optimum pH was 6.0. After this step, the adsorption parameters of Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich isotherms were investigated. It has been pointed out that the adsorption process fits better with the Freundlich isotherm model, and the adhesion occurs in a multilayered manner and on a heterogeneous surface. Freundlich and Dubinin-Radushkevich isotherms support that the bonding mechanism is realized by physical interactions. When the kinetic data were evaluated, adsorption mechanism was found to be compatible with the pseudo-second-order kinetic model. The thermodynamic parameters of adsorption indicate that the system is endothermic, and the adsorption of reactive blue 19 on activated carbon is a spontaneous process.
Removal of 17β-estradiol from aqueous systems with hydrophobic microspheres
(Journal of Polymer Engineering, 2021) Alacabey, İhsan; Kireç, Osman; Alkan, Hüseyin; Erol, Kadir
Sub-microparticles have many applications in different fields today. In this study, it is aimed to develop hydrophobic microparticles as an alternative to existing methods and to determine the 17β-estradiol adsorption performance of this adsorbent to purify the 17β-estradiol hormone which is found as an endocrine disruptor in environmental waters with high capacity and low cost. In this study, L-phenylalanine containing Poly(HEMA-MAPA) microparticles were synthesized by microemulsion polymerization and used as adsorbent. Microparticles were characterized by Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscope (SEM) methods. The size of the Poly(HEMA-MAPA) microparticles used was measured as 120-200 nm. Specific surface area and elemental analysis studies were also conducted. While the surface area of the particles was found to be a very high value of 1890 m2/g, the amount of incorporation of MAPA into the polymeric structure was calculated as 0.43 mmol/g. Adsorption studies were carried out in the batch system under different ambient conditions (17β-estradiol concentration, temperature, ionic intensity). The adsorption capacity of Poly(HEMA-MAPA) microparticles was calculated to be 98.4 mg/g. Isotherm models for adsorption interaction were investigated deeply, and it was determined that the adsorption mechanism is suitable for Langmuir isotherm.