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    Effective uranium biosorption by macrofungus (Russula sanguinea) from aqueous solution: equilibrium, thermodynamic and kinetic studies
    (SPRINGER, 2018) Bagda, Esra; Sari, Ahmet; Tuzen, Mustafa
    Russula sanguinea (R. sanguninea) macrofungus was employed as a novel cost-effective biosorbent for efficient removal of U(VI) ions from aqueous solution. FT-IR spectroscopy and SEM/EDS technique were used for morphological and chemical characterizations. The maximum adsorption capacity of the macrofungus was found as 174.3 mg/g at pH 5 and 20 A degrees C. The kinetic data best fit with the pseudo-second-order kinetic model (r (2) > 0.99 for the studied temperatures). The exothermic and spontaneous nature of the biosorption process was confirmed by the thermodynamic findings. The reusability test demonstrated that the macrofungus had a good sorption/desorption performance.
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    Equilibrium, thermodynamic and kinetic investigations for biosorption of uranium with green algae (Cladophora hutchinsiae)
    (ELSEVIER SCI LTD, 2017) Bagda, Esra; Tuzen, Mustafa; Sari, Ahmet
    Removal of toxic chemicals from environmental samples with low-cost methods and materials are very useful approach for especially large-scale applications. Green algae are highly abundant biomaterials which are employed as useful biosorbents in many studies. In the present study, an interesting type of green algae, Cladophora hutchinsiae (C. hutchinsiae) was used for removal of highly toxic chemical such as uranium. The pH, biosorbent concentration, contact time and temperature were optimized as 5.0, 12 g/L, 60 min and 20 degrees C, respectively. For the equilibrium calculations, three well known isotherm models (Langmuir, Freundlich and Dubinin-Radushkevich) were employed. The maximum biosorption capacity of the biosorbent was calculated as about 152 mg/g under the optimum batch conditions. The mean energy of biosorption was calculated as 8.39 kJ/mol from the D-R biosorption isotherm. The thermodynamic and kinetic characteristics of biosorption were also investigated to explain the nature of the process. The kinetic data best fits the pseudo-second-order kinetic model with a regression coefficient of > 0.99 for all studied temperatures. The calculated Delta H degrees and Delta G degrees values showed that the biosorption process is exothermic and spontaneous for temperatures between 293 and 333 K. Furthermore, after seven cycling process, the sorption and desorption efficiencies of the biosorbent were found to be 70, and 58%, respectively meaning that the biosorbent had sufficiently high reusability performance as a cleanup tool. (C) 2017 Elsevier Ltd. All rights reserved.
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    Factorial design, physical studies and rapid arsenic adsorption using newly prepared polymer modified perlite adsorbent
    (Elsevier, 2022) Saleh, Tawfik A.; Tuzen, Mustafa; Sari, Ahmet; Altunay, Nail
    In this work, expanded perlite (EP) was modified with a polymer of trimesoyl chloride and phenylenediamine, and evaluated as a novel competent adsorbent for aquatic arsenic (As (III)) removal. The chemical structure and morphology of the developed polymer-modified EP (PM-EP) adsorbent were investigated by Fourier transform infrared spectroscopy, as well as scanning electron microscope /energy equipped with dispersive X-ray spectroscope. The conditions of batch removal such as the solution pH, contact time, sorbent dosage, and initial As(III) concentration were analyzed by factorial design. Based on the non-linear and linear Langmuir model that well correlates equilibrium data, the removal capacity of the produced PM-EP adsorbent was estimated as 447.9 mg g-1 and 454.5 mg g-1, respectively at optimized conditions (pH: 6; contact time: 60 min; adsorbent dosage: 10 g L-1 and temperature: 24 degrees C). The As(III) adsorption mechanism onto PM-EP adsorbent was well described by the non-linear pseudo-second-order kinetic model. The prepared PM-EP adsorbent was subjected to a ten cycling-adsorption/desorption test and the results demonstrated that it had appreciated reuse performance until seven cycles. The removal efficiency of PM-EP was determined in the case of wastewater samples. The overall evaluation suggested that the synthesized PM-EP adsorbent could be a powerful alternative adsorbent for decontamination of As(III) ions from wastewaters and drinking waters.(c) 2022 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.
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    A Severe Congenital Neutropenia Type 4 Case (G6PC3 Mutation) Presented With Large Platelets in the Peripheral Smear
    (LIPPINCOTT WILLIAMS & WILKINS, 2016) Cihan, Meric Kaymak; Bolat, Fatih; Onay, Huseyin; Sari, Ahmet; Korgali, Elif Unver; Aslan, Sukran; Cura, Ceylan; Icagasioglu, Dilara
    Severe congenital neutropenia type 4 is a disorder of the hematopoietic system associated with mutations in the glucose-6-phosphatase catabolic 3 (G6PC3) gene. This disorder is characterized by neutropenia, congenital heart defects, urogenital malformations, and prominent superficial veins. To our knowledge, although intermittent thrombocytopenia is observed in this mutation, the coexistence of large thrombocytes is rarely seen. Here we present a case of severe congenital neutropenia type 4 with G6PC3 mutation and large platelets in the peripheral smear.
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    Synthesis of carbon modified with polymer of diethylenetriamine and trimesoyl chloride for the dual removal of Hg (II) and methyl mercury ([CH3Hg]+) from wastewater: Theoretical and experimental analyses
    (Elsevier Science Sa, 2022) Tuzen, Mustafa; Sari, Ahmet; Mogaddam, Mohammad Reza Afshar; Kaya, Savas; Katin, K. P.; Altunay, Nail
    A novel adsorbent was synthesized by modification of waste rubber tiers derived activated carbon (AC) with diethylenetriamine (DETA)-trimesoyl chloride (TMC) copolymer. The synthesized AC/DETA-TMC nanocomposite was characterized by FT-IR and SEM/EDX techniques. Dependency of the adsorption yield on the batch parameters was studied via factorial design method. From the non-linear Langmuir isotherm model, the adsorption capacity of the AC/DETA-TMC nanocomposite was determined as 317.3 and 263.6 mg g 1 for inorganic mercury (Hg2+) and organic mercury (methyl mercury; [CH3Hg]+, respectively. The adsorption kinetic mechanism of both mercury species was recognized well by the PSO model. The thermodynamic calculations verified that the adsorption processes progressed spontaneously and exothermically. The cycling adsorption/ desorption treatments exposed that the produced nanocomposite showed still reusable performance in moderate level until seven cycles. The nanocomposite demonstrated high removal performance in case of wastewater samples. To investigate the power of the interactions between studied chemical species, DFT calculations were performed and adsorption energies were calculated. It is important to note that theoretical results support the experiments made.
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    Thermodynamics and Kinetics of Biosorption of Vanadium with Macrofungus (Hypholoma fasciculare) and Determination by GFAAS
    (PERKIN-ELMER CORP, 2018) Bagda, Esra; Tuzen, Mustafa; Sari, Ahmet; Shemsi, Ahsan Mushir; Bukhari, Alaadin A.
    In the present study, a macrofungus, Hypholoma fasciculare (H. fasciculare), was employed for the biosorption of vanadium from aqueous solutions. The characterization of H. fasciatlare was conducted using the FT-IR and SEM-EDS techniques before and after biosorption. The batch experimental parameters that affect the biosorption of vanadium on the macrofungus were optimized. The Langmuir, Freundlich, and D-R isotherms were employed, and it was found that the Langmuir and D-R models best explained the adsorption mechanism. The kinetic and thermodynamic characteristics of the biosorption mechanism were investigated in detail. The Langmuir biosorption capacity was found as 159.7 mg/g. The thermodynamic parameters showed that the biosorption of vanadium on the macrofungus was more feasible by decreasing the temperature and the exothermic character of Delta G degrees= -20.6 kJ/mol at 293 K and Delta G degrees= -19.9 kJ/mol at 323 K; Delta H degrees= -26.9 kJ/mol, Delta S degrees= -21.8 J/mol. K. The biosorption kinetics of vanadium onto the macrofungus H. lascictifare was best fitted with pseudo-second-order (R-2 >= 0.99). The desorption studies showed that 0.50 M of HNO3 effectively desorbs vanadium from H. fasciculare.