Yazar "Gumus, Fatih" seçeneğine göre listele

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    First Molecular Record and Distribution of Padina pavonica (Linnaeus) Thivy from the Southern Black Sea
    (Central Fisheries Research Inst, 2021) Gumus, Fatih; Gonulol, Arif
    Padina is a brown algal genus widely distributed in warm-temperate and tropical regions. Species-level identification of specimens is often difficult due to intraspecific and interspecific morphological plasticity. This study reveals the results of the phylogenetic relationships of specimens, by analyzing the cytochrome oxidase subunit 3 (Cox3) and RuBisCO large subunit (rbcL) gene sequences. A total of 144 new sequences were analyzed together with other Padina sequences obtained from GenBank. Phylogenetic inference identified one well-resolved clade. All of these analyses showed that this genus has only one species in the Black Sea. This is the first study on the molecular diagnosis of macroalgae in the Black Sea, and it contains the first molecular records of Padina in the Black Sea Region.
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    Modeling heavy metal removal by retention on Laurus nobilis leaves biomass: linear and nonlinear isotherms and design
    (Taylor & Francis Inc, 2020) Gumus, Dilek; Gumus, Fatih
    Heavy metal industries pose a serious threat to the environment. Conventional methods used for heavy metal removal are generally not always low-cost and environmentally friendly. So, researchers focused to investigate alternative biosorbents for the uptake of heavy metal. In this study, Laurus nobilis leaves (LNL) were used as a biosorbent for the uptake of toxic metals such as Pb2+ and Cd2+ from aqueous solutions. Batch biosorption experiments under varied conditions, such as biosorbent dosage, solution pH, heavy metal concentration, biosorption time, ionic strength, humic acid effect and competitive metal ions (Cd(II), Pb(II), Cu(II) and Zn(II)) were performed. The biomass was characterized using FT-IR spectra and SEM images. The nonlinearized and linearized isotherm models were compared and discussed. A single-stage batch bioreactor system for each heavy metal based on the best fit nonlinear isotherm model also has been presented. The biosorption of Pb(II) on LNL fitted better in the Langmuir model and Cd(II) biosorption fitted better in the Freundlich model by nonlinearized equations. The LNL exhibited the maximum monolayer biosorption capacities (q(max)) of 7.1 and 32.5 mg/g for cadmium and lead, respectively. LNL showed great potential especially in Pb(II) uptake. LNL may be promising for heavy metal removal from aqueous environment.
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    Removal of Cefdinir from Water Using Waste Material-Derived Activated Biochar as a Rapid, Effective, and Sustainable Adsorbent
    (Wiley, 2021) Gumus, Dilek; Yumak, Tugrul; Gumus, Fatih
    Cefdinir adsorption onto non-activated biochar (WL-BC) and activated biochars (WL-BC-H, WL-BC-OH) prepared from waste biomass (WL) is comparatively investigated in view of adsorption factors, adsorption isotherms and adsorption kinetics. Batch experiments are conducted to assess the effects of pH, adsorption time and initial antibiotic concentration. Various advanced techniques are applied to characterize the prepared biochars (BCs). Characterization of the new BCs reveal that the activation process do not have a significant effect on the chemical structure of activated carbons, but it increases the surface area up to eight times. The equilibrium data are simulated with the Langmuir adsorption model indicating monolayer adsorption for both activated biochars WL-BC and WL-BC-H. However, the adsorption isotherm for WL-BC-OH is represented well by the Freundlich model, which shows that multilayer adsorption took place. The kinetic data are analyzed using various kinetic models. The maximum adsorption capacity of the activated biochar is approximately tenfold in comparison to the non-activated biochar. Additionally, the real wastewater experiments with treated campus wastewater show that the adsorptive performance of the activated biochar is not affected by other ions. Consequently, BCs derived from defatted laurel leaves could be effective and eco-friendly adsorbents for removing cefdinir from wastewater.
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    Removal of Hydroxychloroquine Using Engineered Biochar from Algal Biodiesel Industry Waste: Characterization and Design of Experiment (DoE)
    (Springer Heidelberg, 2022) Gumus, Dilek; Gumus, Fatih
    Adsorption of hydroxychloroquine (HCQ) onto H3PO4-activated Cystoseira barbata (Stackhouse) C. Agardh (derived from algal biodiesel industry waste) biochar was investigated via batch experiments and mathematical models. The activated biochar (BC-H) was produced in a single step by using the microwave irradiation method. Thus, it was obtained with a low cost, energy efficiency and by promoting clean production processes. BC-H exhibited a remarkable adsorption efficiency (98.9%) and large surface area (1088.806 m(2) g(-1)) for removal of HCQ. The Langmuir isotherm and the pseudo-second-order kinetic models were the best fit for the equilibrium adsorption and kinetics experiments, and the maximum monolayer adsorption capacity (qmax) was found to be 353.58 mu g g(-1). Additionally, the experiments with real wastewater showed that BC-H's ability to adsorb HCQ was not affected by competitive ions in the water. The Taguchi orthogonal array (L16 OA) experimental design was applied for the effective cost optimization analyses of the adsorption process by considering four levels and four controllable factors (initial pH, HCQ concentration, amount of adsorbent and contact time). Scanning electron microscopy, Fourier transform infrared spectroscopy and Brunauer-Emmett-Teller analyses were used for characterizing the adsorbent. The findings showed that BC-H can be used as an effective and low-cost adsorbent in the removal of HCQ from water.
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    The use of a wetland plant as a new biosorbent for treatment of water contaminated with heavy metals: Nonlinear analyses, modification, competitive effects
    (Elsevier, 2019) Gumus, Dilek; Gumus, Fatih
    The aim of this study was to evaluate the biosorption capacity of a wetland plant Juncus effusus for elimination of toxic heavy metals such as Cd2+ and Cu2+ from aqueous solutions. The effects of pH, biosorbent amount, biosorption time, heavy metal concentration, ionic strength, humic acid (HA), modification and competitive metal ions such as cadmium, lead, copper and zinc on biosorption efficiency were investigated in a batch biosorption process. J. effusus biomass was characterized by using SEM analysis and FT-IR spectra. The Freundlich, Langmuir and Temkin isotherm models were used to describe the biosorption equilibrium of Cd2+ and Cu2+ for J. effusus. The isotherms of biosorption of Cu2+ and Cd2+ ions were best described by the Freundlich and Langmuir models, respectively. The kinetic data of biosorption were modeled with the Elovich, the pseudo-first-order, pseudo-second-order and intra-particle diffusion model equations. The kinetic data were successfully described by the pseudo-firstorder model. The biosorption processes, which used sodium hydroxide as the chemical modification material, exhibited the best performance in a wide pH range (4-7). The results confirmed that the biosorbent, which was prepared out of a wetland plant, could be used as an inexpensive and abundant biosorbent for removing metal ions from waters contaminated with heavy metals. (C) 2019 Elsevier B.V. All rights reserved.
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    Utilization of Algal Waste Biomass-Derived Biochar Prepared by a Microwave-Assisted Method for Aniline Green Adsorption
    (Springer Int Publ Ag, 2022) Gumus, Fatih
    In this study, environmentally friendly activated biochar was produced from the wastes of the algal biodiesel industry (Gongolaria barbata (Stackhouse) Kuntze) using a microwave-assisted method. It was used as an adsorbent to remove hazardous aniline green dye from wastewater. The biochar, activated with phosphoric acid (BCH) was prepared in one step by a microwave-assisted method. Scanning electron microscopy (SEM), pH(pzc) (pH at point of zero charges), Fourier transform infrared spectroscopy (FTIR), and Brunauer-Emmett-Teller (BET) techniques were used for the characterization of the adsorbent. The activated biochar presented a micropore volume of 0.181 cm(3) g(-1) and S-BET of 1089 m(2) g(-1). The effects of contact time, pH, and adsorbent amount on the adsorption were investigated. The optimal condition for the maximum adsorption of aniline green (AG) was found as pH (7.0), adsorbent amount (1 g L-1), equilibrium time (40 min), and pollutant concentration (50 mg L-1). The maximum removal percentage was proved to be 99.9% of AG removal. Analyses of experimental data were discussed using nonlinear model equations. The isotherm model can be well described by the Freundlich model. The pseudo-second-order model was suitable for the adsorption kinetics. The reusability ability of BCH for AG dye uptake was found to be 88.3% and 71.6%, for the 50 and 100 mg L-1 pollutant concentrations, respectively, after the third cycle. Three cycles of adsorption and desorption showed that activated biochar is reusable. The economic analysis based on electricity consumption proved that the prepared adsorbent is suitable for large-scale use.