scholarly journals Translocation of Cations During Sorption of Copper in the System Solution - Algae (Spirogyra sp.)/Translokacja Kationów Podczas Procesu Sorpcji Miedzi W Układzie Roztwór - Glony (Spirogyra Sp.)

2014 ◽  
Vol 21 (3) ◽  
pp. 425-433
Author(s):  
Małgorzata Rajfur ◽  
Andrzej Kłos ◽  
Jan Kříž
Keyword(s):  
Order Reaction ◽  
Static System ◽  
Second Order Reaction ◽  
System Solution ◽  
Fixed Proportion ◽  
Pseudo Second Order ◽  
The Difference ◽  
Kinetics Of ◽  
Copper Cations ◽  
Solution Volume

Abstract Kinetics of the sorption of copper cations in Spirogyra sp. algae was analysed, together with the accompanying processes of hydrogen cations sorption and releasing to the solution the cations bonded in the algae: Na+, Mg2+, K+ and Ca2+. It was established that, in a static system, at the fixed proportion of algae mass to the solution volume, these processes occur simultaneously, however presumably the quantity of the released salts influences the parameters of heterophase equilibrium of ion exchange. In the experiment conditions, the quantity of the released cations was nearly 10 times larger than the quantity of the sorbed cations. The equilibrium parameters, determined from the model of pseudo second order reaction, were compared with the parameters obtained after 30 min of the process duration, ie at relatively stable indications of measuring equipment. On the example of the sorbed copper, the difference is approximately 8%. It was confirmed that the solution conductivity is a good parameter for the estimation of the state close to equilibrium.

scholarly journals Adsorption of Methylene Blue on the Composite Sorbent Based on Bentonite-Like Clay and Hydroxyapatite

2018 ◽  
Vol 18 (4) ◽  
pp. 733 ◽  
Author(s):  
Alexandr Ivanovich Vezentsev ◽  
Dang Minh Thuy ◽  
Lidia Fedotovna Goldovskaya-Peristaya ◽  
Nadezhda Alexandrovna Glukhareva
Keyword(s):  
Methylene Blue ◽  
Order Reaction ◽  
Composite Sorbent ◽  
Second Order Reaction ◽  
Isotherm Equation ◽  
Kinetic And Thermodynamic Parameters ◽  
Langmuir Isotherm Equation ◽  
Pseudo Second Order ◽  
Kinetics Of ◽  
Maximal Sorption Capacity

The adsorption of methylene blue from model aqueous solutions on bentonite-like clay, hydroxyapatite, and a composite sorbent has been investigated. The kinetic and thermodynamic parameters of adsorption in the temperature range 298–333 К have been calculated. The process is found to obey Langmuir isotherm equation. It is spontaneous but slightly endothermic. The maximal sorption capacity of the composite sorbent toward methylene blue is 175.4 mg/g at 25 °С that is 1.3 times more than that for bentonite-like clay and 17.8 times more than that for hydroxyapatite. Kinetics of the process is due to the combination of external and internal diffusion and can be described better by the model of pseudo-second order reaction.

Kinetics of the reaction between hexamethylenediisocyanate and 1-pentanol

1983 ◽  
Vol 48 (11) ◽  
pp. 3279-3286
Author(s):  
Slavko Hudeček ◽  
Miloslav Bohdanecký ◽  
Ivana Hudečková ◽  
Pavel Špaček ◽  
Pavel Čefelín
Keyword(s):  
Liquid Chromatography ◽  
Rate Constants ◽  
Reversed Phase ◽  
Order Reaction ◽  
Second Order ◽  
Second Order Reaction ◽  
Reversed Phase Liquid Chromatography ◽  
Consecutive Reactions ◽  
Phase Liquid ◽  
Kinetics Of

The reaction between hexamethylenediisocyanate and 1-pentanol in toluene was studied by means of reversed-phase liquid chromatography. By employing this method, it was possible to determine all components of the reaction mixture including both products, i.e. N-(6-isocyanate hexyl)pentylcarbamate and N,N'-bis(pentyloxycarbonyl)hexamethylenediamine. Relations for the calculation of kinetic constants were derived assuming a competitive consecutive second-order reaction. It was demonstrated that the reaction involved in this case is indeed a second-order reaction, and the rate constants of the first and second consecutive reactions were determined.

scholarly journals Water defluoridation by alumina modified Turkey clinoptilolite: equilibrium, kinetic models and experimental design approaches

2017 ◽  
Vol 18 (1) ◽  
pp. 14-22 ◽  
Author(s):  
Selim Selimoglu ◽  
Esra Bilgin Simsek ◽  
Ulker Beker
Keyword(s):  
Natural Zeolite ◽  
Kinetic Studies ◽  
Order Reaction ◽  
Operating Conditions ◽  
Second Order Reaction ◽  
Freundlich Model ◽  
Box Behnken Design ◽  
Fluoride Adsorption ◽  
Exothermic Process ◽  
Pseudo Second Order

Abstract In the current work, alumina modified natural zeolite (Z-Al) was used for fluoride adsorption in aqueous solution. Effects of process parameters such as pH, temperature, initial concentration and contact time were investigated. Box–Behnken design was found effective in defining the operating conditions for fluoride sorption onto Z-Al. Confirmatory experiments were conducted to examine the reliability of the regression equation. The predicted (2.261 mg g−1) and experimental (2.289 mg g−1) capacities were found to be similar, demonstrating the accuracy of the model. The fluoride adsorption onto Z-Al was well described by the Freundlich model. Kinetic studies revealed that the adsorption followed a pseudo-second-order reaction. Thermodynamic parameters depicted that the fluoride adsorption on the alumina modified zeolite was a spontaneous and exothermic process. The co-existing ions affected the defluoridation performance significantly. Regeneration of exhausted Z-Al was achieved with H2SO4.

scholarly journals SOLVATION OF THE [Cr(NCS)4(IMIDAZOLE)2] ION IN ETHANOL-WATER MIXTURES

2002 ◽  
Vol 10 (11) ◽  
pp. 63-72
Author(s):  
lon Ganescu ◽  
George Bratulescu ◽  
Ion Papa ◽  
Anca Ganescu ◽  
Alin Barbu ◽  
...  
Keyword(s):  
Kinetic Parameters ◽  
Order Reaction ◽  
Water Molecules ◽  
Hydrogen Ions ◽  
Second Order Reaction ◽  
Acidic Solutions ◽  
The Third ◽  
Competitive Reactions ◽  
Different Temperatures ◽  
Kinetics Of

Salvation kinetics of [Cr(NCS)4(imidazole)2]- has been studied in ethanol-water mixtures at different temperatures. The first stage of the solvation consists of two competitive reactions: two NCS- ions are exchanged, presumably, by water molecules and simultaneously an imidazole molecule by ethanol, the latter in a second-order reaction, accelerated by hydrogen ions. The exchange of the amine is followed by the substitution of the first two NCS- ions. The third and fourth NCS- ions are substituted only in neutral and slightly acidic solutions. Kinetic parameters have been determined for reactions (1), (2), and (4). The influence of the solvent composition and acidity is discussed

scholarly journals The alcoholysis of 1,2,2-trimethylpropyl-methylfluorophosphonate

2000 ◽  
Vol 65 (12) ◽  
pp. 857-866
Author(s):  
Mladjen Micevic ◽  
Slobodan Petrovic
Keyword(s):  
Kinetic Data ◽  
Reaction Rate ◽  
Frequency Factor ◽  
Reaction Rate Constant ◽  
Order Reaction ◽  
Activation Entropy ◽  
Second Order Reaction ◽  
Third Order ◽  
First Order ◽  
Kinetics Of

The alcoholysis of 1,2,2-trimethylpropyl-methylfluorophosphonate (soman) was examined with a series of alkoxides and in corresponding alcohols: methanol, ethanol, 1-propanol, 2-propanol, 2-methoxyethanol and 2-ethoxyethanol. Soman reacts with the used alkoxides in a second order reaction, first order in each reactant. The kinetics of the reaction between 1,2,2-trimethylpropyl-methylfluorophosphonate and ethanol in the presence of diethylenetriamine was also examined. A third order reaction rate constant was calculated, first order in each reactant. The activation energy, frequency factor and activation entropy were determined on the basis of the kinetic data.

Studies in the Vulcanization of Rubber. III—Kinetics of Vulcanization of Rubber with Sulfur and Selenium

1930 ◽  
Vol 3 (4) ◽  
pp. 650-659
Author(s):  
John T. Blake
Keyword(s):  
Molecular Weight ◽  
Order Reaction ◽  
Order Equation ◽  
Second Order Reaction ◽  
Experimental Conditions ◽  
Mathematical Basis ◽  
First Order ◽  
Kinetics Of ◽  
Kinetics Of Vulcanization

Abstract A procedure for the determination of combined selenium in rubber has been evolved. The rate of combination of selenium and rubber has been ascertained under certain conditions and shown to follow a first-order equation. A minimum value for the molecular weight of rubber has been estimated. The formation of hard rubber under chosen experimental conditions has been put on a mathematical basis and has been shown to follow a second-order reaction. The soft- and hard-rubber reactions have been shown qualitatively to be successive reactions and the function of accelerators has been discussed. The theory explains the anomalous results obtained by previous investigators.

scholarly journals Removal of Cd(II) Ions from Simulated Wastewater by HCl Modified Cucumis sativus Peel: Equilibrium and Kinetic Study

2014 ◽  
Vol 7 ◽  
pp. ASWR.S16488 ◽  
Author(s):  
Ruchi Pandey ◽  
Nasreen Ghazi Ansari ◽  
Ram Lakhan Prasad ◽  
Ramesh Chandra Murthy
Keyword(s):  
Cucumis Sativus ◽  
Adsorption Process ◽  
Order Reaction ◽  
Ion Concentration ◽  
Second Order Reaction ◽  
Monolayer Adsorption ◽  
Optimum Ph ◽  
Pseudo Second Order ◽  
Simulated Wastewater ◽  
Maximum Removal

This paper describes the adsorption of Cd(II) ions from aqueous solutions by modified Cucumis sativus peel (CSP) by HCl treatment. The optimum pH, adsorbent mass, contact time, and initial ion concentration were determined. The maximum removal efficiency was 84.85% for 20 mg/L Cd(II) ion at pH 5. The adsorption isotherms were obtained using concentrations of the metal ions ranging from 5 to 150 mg/L. The adsorption process follows Langmuir isotherm and pseudo-second-order reaction kinetics. CSPs exhibit monolayer adsorption capacity of 58.14 mg/g at 298 K. The paper also discusses the thermodynamic parameters of the adsorption (the Gibbs free energy, entropy, and enthalpy). Our results establish that the adsorption process was spontaneous and endothermic under normal conditions.

scholarly journals The Use of Bauxite as an Arsenic Filter

2019 ◽  
Vol 19 (2) ◽  
pp. 55-63
Author(s):  
S. A. Ndur ◽  
H. Osei ◽  
C. E. Abbey ◽  
T. Joe-Asare
Keyword(s):  
Sorption Isotherm ◽  
Order Reaction ◽  
Desorption Rate ◽  
Second Order Reaction ◽  
Metal Mining ◽  
Keywords Arsenic ◽  
Remediation Strategies ◽  
Public Health Challenges ◽  
Good Filter ◽  
Pseudo Second Order

AbstractArsenic (As) has the potential to negatively affect soils and groundwater quality, and cause several public health challenges. It is usually concentrated and released during metal mining of ores that contains arsenic-bearing minerals. Remediation strategies are in place to avoid pollution. In this study, bauxite from Awaso, Ghana, was characterised, and its ability to sequester As was tested under varying conditions of temperature, Eh and pH. The study showed that the best particle size in the range utilised was 80% passing 2 mm as it allowed easy percolation, and As removal was about 95%. The reaction is a favourable pseudo-second order reaction that is spontaneous and thermodynamically stable and compares well with the Langmuir Sorption Isotherm. About 80% sorption was achieved within 20 minutes of contact with low desorption rate of less than 1.8%. The study thus concludes that bauxite is a good filter for arsenic. Keywords: Arsenic, Bauxite, Filter, Sorption, Isotherm

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