Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 19 of 19

Full-Text Articles in Physical Sciences and Mathematics

Evaluation Of P(Hema-Co-Nipam) Hydrogels For Removal Of Methylene Blue From Aqueous Solution:Isotherm, Kinetic, And Thermodynamic Studies, Hayri̇ye Mi̇ne Antep, Müni̇re Nalan Demi̇r, Cevher Gündoğdu Hizliateş, Si̇mge Öztürk, Eli̇f Esen Apr 2024

Evaluation Of P(Hema-Co-Nipam) Hydrogels For Removal Of Methylene Blue From Aqueous Solution:Isotherm, Kinetic, And Thermodynamic Studies, Hayri̇ye Mi̇ne Antep, Müni̇re Nalan Demi̇r, Cevher Gündoğdu Hizliateş, Si̇mge Öztürk, Eli̇f Esen

Turkish Journal of Chemistry

In this study, a novel adsorbent material, poly (2-hydroxyethyl methacrylate-co-N-isopropyl acrylamide) (p(HEMA-co-NIPAM) hydrogel, was synthesized for the purpose of removing methylene blue (MB) from aqueous media. The synthesis of hydrogel was carefully conducted, and its properties were thoroughly examined using techniques such as Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The adsorption experiments conducted revealed a remarkable affinity of p(HEMA-co-NIPAM) hydrogel towards MB. The highest adsorption was observed when 0.05 g of the adsorbent were utilized, with optimal conditions at a pH of 6.0 and a temperature of 15 °C. This underscores the importance of …


Parametric And Kinetic Study Of Solvent-Free Synthesis Of Solketal Using Ion Exchange Resin, Dheer A. Rambhia, Sravanthi Veluturla, Archna Narula Jan 2022

Parametric And Kinetic Study Of Solvent-Free Synthesis Of Solketal Using Ion Exchange Resin, Dheer A. Rambhia, Sravanthi Veluturla, Archna Narula

Turkish Journal of Chemistry

The ketalization reaction of glycerol with acetone for solketal formation was performed using a gel-type ion exchange resin, Indion 225H in a solvent-free medium. The experimental parameters molar ratio, catalyst loading, rate of stirring, and temperature were analyzed and evaluated for their impact on the conversion of glycerol. A kinetic model based on the Langmuir-Hinshelwood?Hougen- Watson (LHHW) equation described the kinetics of the heterogeneous system. The parameters were evaluated using the ode45 solver and Genetic Algorithm (GA) optimization function on MATLAB software. The activation energy for the ketalization of glycerol was found to be 39.3 kJ/mol, the enthalpy of adsorption …


Kinetic, Isotherm, And Thermodynamic Studies For Adsorptive Removal Of Basic Violet 14 From Aqueous Solution, Yasemi̇n Tamer, Hale Berber Jan 2022

Kinetic, Isotherm, And Thermodynamic Studies For Adsorptive Removal Of Basic Violet 14 From Aqueous Solution, Yasemi̇n Tamer, Hale Berber

Turkish Journal of Chemistry

In this study, the performance of chitosan based semi-IPN nanocomposite hydrogels for the adsorptive removal of basic violet 14 (BV14) from aqueous solution has been explored. Batch adsorption studies were conducted to determine the effect of various parameters on BV14 adsorption, and optimum values were reported as pH of 8, the adsorbent dosage of 0.025 g, initial BV14 concentration of 5 mg L-1 and contact time of 90 min at a temperature of 25 °C. The semi-IPN hydrogel containing 0.5% by weight GO showed the improved adsorption capacity for BV14 compared to the neat hydrogel adsorbent, and the maximum …


Process Optimization And Mechanism Study Of Acid Red G Degradation By Electro-Fentonfeox Process As An In Situ Generation Of H2o2, Hailong Sun, Yingwu Yao, Feng Wei, Qiang Zhao, Baichen Liu, Liman Zhang Jan 2021

Process Optimization And Mechanism Study Of Acid Red G Degradation By Electro-Fentonfeox Process As An In Situ Generation Of H2o2, Hailong Sun, Yingwu Yao, Feng Wei, Qiang Zhao, Baichen Liu, Liman Zhang

Turkish Journal of Chemistry

Dye-contaminated wastewaters are industrial wastewaters that are difficult to treat using traditional biochemical and physicochemical methods. In the present work, the acid red G was removed as a model pollutant by the electro-Fenton process for the first time. The anode and cathode used by the electro-Fenton process were iron plate and graphite felt, respectively. It was concluded that under the optimal conditions of current density = 20 mA cm-2, pH = 3 and initial Na2SO4 concentration = 0.2 M, the removal rate of acid red G (ARG) with an initial concentration of 300 mg L-1 could reach 94.05% after 80 …


An Evaluation Of The Adsorption Dynamics Of Phosphate Ions Onto Fe(Ii)-Montmorillonites, Dawei Qin, Shuhua Chang, Min Qiao, Xiaotong Yuan, Wei Liu, Gang Liu Jan 2019

An Evaluation Of The Adsorption Dynamics Of Phosphate Ions Onto Fe(Ii)-Montmorillonites, Dawei Qin, Shuhua Chang, Min Qiao, Xiaotong Yuan, Wei Liu, Gang Liu

Turkish Journal of Chemistry

Fe(II)-montmorillonites (Fe(II)-MMTs) were prepared by mixing solutions of Fe(II) and montmorillonite at pH 3.5. Two different Fe(II)-MMTs were prepared and the ferrous iron contents were 40 mg/L and 80 mg/L. All samples were characterized by XRD, FT-IR, TGA, DSC, and nitrogen adsorption. By nitrogen adsorption, the pore size can be obtained in the pore diameter curve with average pore widths of 6.67 nm, 9.96 nm, and 17.07 nm, respectively. The removal rate of phosphate increased rapidly during the first 40 min, in which Fe(II)-MMT (1) and Fe(II)-MMT (2) were stronger adsorption systems than MMT. The maximum adsorption was 48.38 mg/g …


Experimental And Theoretical Study Of Nh$_{3}$ Adsorption And Desorption Over A Cu-Chabazite Nh$_{3}$-Scr Catalyst, Selmi̇ Eri̇m Bozbağ, Mutlu Şi̇mşek, Onur Demi̇r, Deni̇z Şanli Yildiz, Hüseyi̇n Barkin Özener, Gökhan Hi̇sar, Can Erkey Jan 2018

Experimental And Theoretical Study Of Nh$_{3}$ Adsorption And Desorption Over A Cu-Chabazite Nh$_{3}$-Scr Catalyst, Selmi̇ Eri̇m Bozbağ, Mutlu Şi̇mşek, Onur Demi̇r, Deni̇z Şanli Yildiz, Hüseyi̇n Barkin Özener, Gökhan Hi̇sar, Can Erkey

Turkish Journal of Chemistry

NH$_{3}$ adsorption and desorption behavior of a commercial Cu-chabazite (CHA) NH$_{3}$ selective catalytic reduction (NH$_{3}$-SCR) catalyst was studied in the presence and absence of H$_{2}$O. NH$_{3}$ uptake values at various adsorption temperatures were obtained during various steps of the adsorption and temperature-programmed desorption (TPD) experiments. Total NH$_{3}$ uptake decreased from 4.6 to 1.6 g NH$_{3}$/L catalyst when the adsorption temperature was increased from 50 to 300 $^{\circ}$C. Three major adsorption sites for NH$_{3}$ adsorption could be identified and quantified using TPD experiments, namely loosely, moderately, and strongly bound NH$_{3}$ with peak centers at around 147, 266, and 447 $^{\circ}$C. The …


Kinetics Of Silver(I)-Catalyzed Oxidation Of Allyl Alcohol By Peroxodiphosphate Inacetate Buffers, Priyamvada Sharma, Riya Sailani, Deepmala Pareek, Chandra Lata Khandelwal Jan 2018

Kinetics Of Silver(I)-Catalyzed Oxidation Of Allyl Alcohol By Peroxodiphosphate Inacetate Buffers, Priyamvada Sharma, Riya Sailani, Deepmala Pareek, Chandra Lata Khandelwal

Turkish Journal of Chemistry

The kinetics and mechanism of silver(I)-catalyzed oxidation of allyl alcohol with peroxodiphosphate in acetate buffers have been studied. The rate is independent of allyl alcohol concentration. The effect of other reaction parameters such as hydrogen and acetate ions has also been studied. The rate law accounting for all experimental observations corresponds to the proposed mechanism. The energy and entropy of activation have also been evaluated by employing Eyring plots.


Removal Of Pb(Ii) And Cd(Ii) From Aqueous Solution Using Alkaline-Modified Pumice Stone Powder (Psp): Equilibrium, Kinetic, And Thermodynamic Studies, Vivian Jonasi, Kaina Matina, Upenyu Guyo Jan 2017

Removal Of Pb(Ii) And Cd(Ii) From Aqueous Solution Using Alkaline-Modified Pumice Stone Powder (Psp): Equilibrium, Kinetic, And Thermodynamic Studies, Vivian Jonasi, Kaina Matina, Upenyu Guyo

Turkish Journal of Chemistry

Adsorption processes of Cd(II) and Pb(II) from aqueous solutions onto pumice stone powder (PSP) were investigated in batch mode. The influences of solution pH, contact time, adsorbent dosage, initial metal (M) concentration, and temperature on adsorption process were investigated. The kinetic and isotherm data were analysed using different model equations. The adsorption process was consistent with the Langmuir model for both metal ions with high R$^{2}$ and low $\chi^{2}$ values for both Pb(II) and Cd(II). The maximum monolayer adsorption capacities were 28.09 and 27.17 mg g$^{-1}$ for Pb(II) and for Cd(II), respectively. The pseudo-second order kinetic model explained the kinetic …


Biosorption Potential Of Surface-Modified Waste Sugar Beet Pulp For The Removal Of Reactive Yellow 2 (Ry2) Anionic Dye, Si̇bel Tunali Akar, Sema Çeli̇k, Di̇lek Tunç, Yasemi̇n Yeti̇moğlu Balk, Tamer Akar Jan 2016

Biosorption Potential Of Surface-Modified Waste Sugar Beet Pulp For The Removal Of Reactive Yellow 2 (Ry2) Anionic Dye, Si̇bel Tunali Akar, Sema Çeli̇k, Di̇lek Tunç, Yasemi̇n Yeti̇moğlu Balk, Tamer Akar

Turkish Journal of Chemistry

Tetra-$n$-butylammonium bromide modified sugar beet pulp (TBAB-SBP) with good biosorption and regeneration potential was prepared for removal of dye from contaminated solutions. The decolorization performance of TBAB-SBP was investigated using Reactive Yellow 2 (RY2) as a model dye. The characterization of the modified biosorbent was investigated by IR, SEM, zeta potential, and BET surface area analysis to discuss the decolorization mechanism. The effects of initial pH, biosorbent amount, contact time, dye concentration, and flow rate on the treatment process were examined. The experimental kinetic data were well predicted by the pseudo-second-order kinetic model and Langmuir isotherm with a maximum monolayer …


Kinetics Study And Influence Of Water-Soluble Polymer On The Electrodeposition Of Iron From A Citrate-Chloride Electrolyte On The Basis Of Fe(Iii), Vyacheslav Protsenko, Felix Danilov Jan 2015

Kinetics Study And Influence Of Water-Soluble Polymer On The Electrodeposition Of Iron From A Citrate-Chloride Electrolyte On The Basis Of Fe(Iii), Vyacheslav Protsenko, Felix Danilov

Turkish Journal of Chemistry

The kinetics of the iron electrodeposition reaction from a plating bath containing trivalent iron ions is investigated in the present work. The electrochemical reaction is stated to proceed via the formation of relatively stable intermediates: Fe(II) ions. Only a part of the total amount of Fe(II) ions formed at the first stage of Fe(III) discharge is reduced further, producing metal iron. The effect of polyhexamethyleneguanidine hydrochloride (with an average molecular weight of 1000) on the iron deposition is ascertained. The presence of polymer additive in the iron electrolyte appreciably affects the rate of iron deposition, while the polymer additive does …


Kinetics Of Co Oxidation Over Pt-Ceo_X Supported On Air-Oxidized Activated Carbon, Berri̇n Gülyüz, Şeyma Özkara Aydinoğlu, Ahmet Erhan Aksoylu, Zeynep İlsen Önsan Jan 2009

Kinetics Of Co Oxidation Over Pt-Ceo_X Supported On Air-Oxidized Activated Carbon, Berri̇n Gülyüz, Şeyma Özkara Aydinoğlu, Ahmet Erhan Aksoylu, Zeynep İlsen Önsan

Turkish Journal of Chemistry

Kinetics of low-temperature CO oxidation was studied under atmospheric pressure at 383 K in the initial rates region over 1wt%Pt-1wt%CeO_x supported on air-oxidized activated carbon (AC2). Feed concentrations of 1-5 mol% CO and 1-2.5 mol% O_2 with balance He were used for CO oxidation in the absence of hydrogen. A simple power-function rate expression was obtained with reaction orders of -0.24 in CO and 0.98 in O_2, and a plausible LHHW expression compatible with mechanisms reported in the literature was proposed. Feed concentrations of 5 mol% CO and 2.5 mol% O_2 were used for investigating the effect of the presence …


Comparison Of Catalytic Activities Of Carbon Supported Pt And Pt-Ru Catalysts For Methanol Oxidation In Neutral And Basic Media By Cyclic Voltammetry, Abdul Sattar Ali Khan, Riaz Ahmed, Muhammad Latif Mirza Jan 2008

Comparison Of Catalytic Activities Of Carbon Supported Pt And Pt-Ru Catalysts For Methanol Oxidation In Neutral And Basic Media By Cyclic Voltammetry, Abdul Sattar Ali Khan, Riaz Ahmed, Muhammad Latif Mirza

Turkish Journal of Chemistry

The catalytic activities of an equal amount of 3 different carbon supported catalysts containing 10% Pt, 20% Pt + 10% Ru, and 30% Pt were evaluated in neutral and basic media for methanol oxidation by cyclic voltammetry. The prominent oxidation peak for methanol appeared in the forward anodic sweep at around 1.0 V in neutral medium, while in basic medium it appeared at significantly lower potential close to 0.2 V. The peak current for methanol oxidation was higher on a catalyst containing higher Pt loading. The comparison of polarization behavior of 20% Pt + 10% Ru and 30% Pt catalysts …


Low Temperature Co Oxidation Kinetics Over Activated Carbon Supported Pt-Sno_X Catalysts, Fatma Soyal Baltacioğlu, Berri̇n Gülyüz, Ahmet Erhan Aksoylu, Zeynep İlsen Önsan Jan 2007

Low Temperature Co Oxidation Kinetics Over Activated Carbon Supported Pt-Sno_X Catalysts, Fatma Soyal Baltacioğlu, Berri̇n Gülyüz, Ahmet Erhan Aksoylu, Zeynep İlsen Önsan

Turkish Journal of Chemistry

The kinetics of low temperature CO oxidation were studied over sequentially impregnated 1wt%Pt-0.25wt%SnO_x supported on HNO_3-oxidized activated carbon (AC3) using a wide range of CO (1-10 mol%) and O_2 (1-4 mol%) concentrations. Intrinsic kinetic data were obtained in the initial rates region at 383 K in the absence and presence of 5-45 mol% H_2 in the feed. A power-function rate expression with positive dependence on CO (0.96) and negative dependence on oxygen (--0.31) was obtained for the low temperature oxidation of CO. The effect of H_2 on CO oxidation rates was also investigated under similar conditions.


The Kinetics Of The Photochemical Reaction Of Methylene Green With Methylamine And Ethylamine, Rehana Saeed, Fahim Uddin, Zahida Khalid Jan 2004

The Kinetics Of The Photochemical Reaction Of Methylene Green With Methylamine And Ethylamine, Rehana Saeed, Fahim Uddin, Zahida Khalid

Turkish Journal of Chemistry

The photochemical reduction of methylene green with methylamine and ethylamine in 50% aqueous isopropanol was studied. The photochemical reduction was carried out in a special type of optical processor associated with a deoxygenating system, a temperature controlling unit and a magnetic stirring system. A monochromatic light of 657 nm wavelength was used for irradiation of oxygen free reaction solutions in a double walled reaction cell. The transmitted light was measured and recorded in terms of electrical signals with the help of a calibrated galvanometer. Acidities of the solutions were measured with the help of a spectrophotometer based on the Hammet …


Kinetics And Mechanism Of Oxidation Of L-Isoleucine And L-Ornithine Hydrochloride By Sodium N-Bromobenzenesulphonamide In Perchloric Acid Medium, Hemmige S. Yathirajan, Chapuradoddi R. Raju, Kikkeri N. Mohana, Sheena Shashikanth, Padmarajaiah Nagaraja Jan 2003

Kinetics And Mechanism Of Oxidation Of L-Isoleucine And L-Ornithine Hydrochloride By Sodium N-Bromobenzenesulphonamide In Perchloric Acid Medium, Hemmige S. Yathirajan, Chapuradoddi R. Raju, Kikkeri N. Mohana, Sheena Shashikanth, Padmarajaiah Nagaraja

Turkish Journal of Chemistry

Kinetic studies of the oxidation of L-isoleucine (ISL) and L-ornithine hydrochloride (ORH) by sodium N-bromobenzenesulphonamide (bromamine-B or BAB) were studied in aqueous perchloric acid medium. The rate shows first-order dependence on both [BAB]_0 and [amino acid]_0 and inverse first-order dependence on [H^+] for ISL and first-order dependence on [H^+] for ORH. The rate of reaction decreased with decreases in the dielectric constant of the medium. The addition of benzenesulphonamide (BSA), which is one of the reaction products, had no significant effect on the reaction rate. The rate remained unchanged with the variation in the ionic strength of the medium for …


Kinetics Of Oxidation Of Pyridylmethylsulphinylbenzimidazole By Cerium(Iv) In An Aqueous Perchloric Acid Medium, Dinesh C. Bilehal, Ravi̇raj M. Kulkarni, Sharanappa T. Nandibewoor Jan 2003

Kinetics Of Oxidation Of Pyridylmethylsulphinylbenzimidazole By Cerium(Iv) In An Aqueous Perchloric Acid Medium, Dinesh C. Bilehal, Ravi̇raj M. Kulkarni, Sharanappa T. Nandibewoor

Turkish Journal of Chemistry

The kinetics of oxidation of pyridylmethylsulphinylbenzimidazole [PMSB] by Ce(IV) in an aqueous perchloric acid medium at a constant ionic strength of 1.50 mol dm^{-3} were studied spectrophotometrically. The reaction showed first order kinetics with respect to Ce(IV) concentration and an apparent less than unit order dependence in [PMSB] and a zero order in [H^+]. The initial addition of products has no significant effect on the rate of the reaction. A possible mechanism is proposed here. The reaction constants involved in the mechanism have been computed. There is good agreement between the observed and calculated rate constants under different experimental conditions. …


The Kinetics And Mechanism Of Oxidation Of Vanillin By Diperiodatonickelate(Iv) In Aqueous Alkaline Medium, Chandrashekhar Kathari, Pandurang Pol, Sharanappa Nandibewoor Jan 2002

The Kinetics And Mechanism Of Oxidation Of Vanillin By Diperiodatonickelate(Iv) In Aqueous Alkaline Medium, Chandrashekhar Kathari, Pandurang Pol, Sharanappa Nandibewoor

Turkish Journal of Chemistry

The title reaction was investigated in aqueous alkaline medium. A first order dependence in diperiodatonickelate (IV) (DPN) and an apparent fractional order in both vanillin and alkali were obtained. Periodate has a retarding effect on the reaction. The effect of added products and the ionic strength of the reaction medium have no significant effect on the reaction rate. A decrease in the dielectric constant of the medium decreases the rate of reaction. Effects of temperature on the rate of reaction were studied. A mechanism based on experimental results was proposed, and constants involved in the mechanism were evaluated. A good …


Oxidation Of Ethylenediaminetetraacetic Acid By N-Bromosuccinimide In Aqueous Alkaline Medium -- A Kinetic Study, S. K. Mavalangi, M. R. Kembhavi, S. T. Nandibewoor Jan 2001

Oxidation Of Ethylenediaminetetraacetic Acid By N-Bromosuccinimide In Aqueous Alkaline Medium -- A Kinetic Study, S. K. Mavalangi, M. R. Kembhavi, S. T. Nandibewoor

Turkish Journal of Chemistry

The kinetics of oxidation of ethylenediaminetetraacetic acid (EDTA) by N-bromosuccinimide (NBS) in aqueous alkaline media was investigated at 25°C. Analysis of the results showed the reaction is first -- order with respect to [NBS] and apparently less than unit order each with respect to [EDTA] and [alkali]. The influence of the reaction products, ionic strength, temperature effect and dielectric constant of the medium on the rate of reaction was studied. The proposed mechanism is consistent with the observed kinetics. The reaction constants involved in the mechanism were derived. There is a good agreement between the observed and calculated rate constants …


Kinetics And Thermodynamics Of Oil Extraction From Sun Ower Seeds In The Presence Of Aqueous Acidic, Hüseyi̇n Topallar, Ümi̇t Geçgel Jan 2000

Kinetics And Thermodynamics Of Oil Extraction From Sun Ower Seeds In The Presence Of Aqueous Acidic, Hüseyi̇n Topallar, Ümi̇t Geçgel

Turkish Journal of Chemistry

Oil extraction was performed in aqueous HCl, H_2SO_4 and H_3PO_4 solutions with n-hexane (C_6H_{14}) at 30, 40, 50 and 60 ^oC using 10 gr of sunflower seeds over 1 h with 10-min. sampling intervals. The optimum acid concentration was wt. 10% for each acid, and the highest oil yield was obtained in the extraction procedure with n-hexane containing H_2SO_4. The extraction process was observed with regard to the percent oil yield versus time, and the reaction order was found to be first-order kinetics by the differential method. The activation energy for the oil extraction kinetics of sunflower seeds with 10% …