scholarly journals Efficient Removal of Ce(III) and Eu(III) Ions from Aqueous Solutions by Local Clay -A Radiotracer Study

2011 ◽  
Vol 8 (2) ◽  
pp. 917-923
Author(s):  
Som Shankar Dubey ◽  
Battula Sreenivasa Rao ◽  
B. S. A. Andrews ◽  
B.Venkata Kiran
Keyword(s):  
Aqueous Solutions ◽  
Freundlich Isotherm ◽  
Efficient Removal ◽  
Local Clay ◽  
Radiotracer Technique ◽  
Adsorption Phenomenon ◽  
First Order ◽  
Rate Kinetics ◽  
Kinetics Of ◽  
Adsorptive Concentration

Radiotracer technique has been used to study the removal behavior of Ce(III) and Eu(III) ions from aqueous solutions by local clay. Adsorptive concentration (10-4–10-6mol dm-3), pH (ca2.0-9.0) and temperature (303-333 K) were examined for assessing optimal conditions for removal of these ions. The adsorption phenomenon was highly dependent on the amount of the adsorbent concentrations. The uptake of ions, which fitted well for Freundlich isotherm, increased with increase in the temperature and no significant desorption took place in the studied temperature range. The energy of adsorption process for the both cations indicates that the adsorption phenomenon is of chemisorption type. The rate kinetics of the adsorption followed the first order rate kinetics.

Adsorption Behavior and Thermodynamic Characteristics of p,p’- DDT on Expanded Graphite

2011 ◽  
Vol 287-290 ◽  
pp. 1653-1658 ◽  
Author(s):  
You Ya Zhou ◽  
Zeng Guang Yan ◽  
Kinam Kim
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Process ◽  
Adsorption Equilibrium ◽  
Thermodynamic Characteristics ◽  
Expanded Graphite ◽  
Freundlich Isotherm ◽  
Type Ii ◽  
Efficient Removal ◽  
First Order ◽  
Water And Wastewater

The adsorption of p,p’-DDT onto expanded graphite (EG) in aqueous solutions was investigated under varying conditions of p,p’-DDT concentrations, adsorbent doses, pH, and contact time. The removal efficiency of p,p’-DDT from the aqueous solutions remained constant in a range of pH 2 to 10, and the thermodynamic data followed the type II adsorption isotherm characterized by a spontaneous process. At lower concentrations, adsorption equilibrium of p,p’-DDT onto EG was fitted to Freundlich isotherm. Dynamic modeling of the adsorption showed that the first order reversible kinetic model was held for the adsorption process within the range of experimental concentration. It was suggested that expanded graphite can be used for efficient removal of p,p’-DDT from water and wastewater.

scholarly journals Kinetics of thiamin cleavage by sulphite

1969 ◽  
Vol 113 (4) ◽  
pp. 611-615 ◽  
Author(s):  
J. Leichter ◽  
M. A. Joslyn
Keyword(s):  
Aqueous Solutions ◽  
Rate Constant ◽  
Sulphur Dioxide ◽  
First Order ◽  
Ph Values ◽  
Rate Of Reaction ◽  
Kinetics Of

Results are presented on the rate of thiamin cleavage by sulphite in aqueous solutions as affected by temperature (20–70°), pH(2·5–7·0), and variation of the concentration of either thiamin (1–20μm) or sulphite (10–5000μm as sulphur dioxide). Plots of the logarithm of percentage of residual thiamin against time were found to be linear and cleavage thus was first-order with respect to thiamin. At pH5 the rate was also found to be proportional to the sulphite concentration. In the pH region 2·5–7·0 at 25° the rate constant was 50m−1hr.−1 at pH5·5–6·0, and decreased at higher or lower pH values. The rate of reaction increased between 20° and 70°, indicating a heat of activation of 13·6kcal./mole.

scholarly journals Sorption of Ni(II) and Cr(III) ions by the Chironomus yoshimatsui larvae from wastewater

2018 ◽  
Vol 15 (1) ◽  
pp. 6062-6069
Author(s):  
Keon Sang Ryoo
Keyword(s):  
Freundlich Isotherm ◽  
Sorption Kinetics ◽  
Isotherm Model ◽  
Sorption Data ◽  
First Order ◽  
Batch System ◽  
Survival Capacity ◽  
Langmuir Isotherm Model ◽  
Treatment Technologies ◽  
Kinetics Of

In this study, Chironomus yoshimatsui larvae were applied to remove Ni(II) and Cr(III) ions from wastewater. The sorption studies were carried out using laboratory-reared C. y. larvae. It was found that C. y. larvae are very susceptible to Cr(III) as compared to Ni(II). The survival capacity of C. y. larvae was sharply reduced when exposed to even low Cr(III) concentration. Sorption isotherm and kinetics of C. y. larvae for Ni(II) were determined by means of controlled experiments in a batch system. It was observed that sorpyion efficiency of Ni(II) was largely concentration dependent and more effective at lower concentration. At each equilibrium, Ni(II) was removed up to roughly 44∼80 %. Sorption data were better fitted to the Langmuir isotherm model because of its correlation coefficient R2 value greater than that of the Freundlich isotherm model. The sorption kinetics by C. y. larvae for Ni(II) was well described a pseudo-first-order rate expression. C. y. larvae have enormous potential for application in wastewater treatment technologies because they are widespread and abundant all around the world and can be easily kept in culture.

The Decomposition of Sodium Nitrite Solutions in Aqueous Sulphuric and Perchloric Acids

1963 ◽  
Vol 16 (6) ◽  
pp. 927 ◽  
Author(s):  
NS Bayliss ◽  
DW Watts
Keyword(s):  
Aqueous Solutions ◽  
Acid Composition ◽  
Sodium Nitrite ◽  
Decomposition Rate ◽  
Rate Constants ◽  
First Order ◽  
Order Dependence ◽  
Gaseous Products ◽  
Kinetics Of

The kinetics of the decomposition of aqueous solutions of sulphuric and perchloric acids containing sodium nitrite have been investigated at a number of temperatures. The technique involved flushing the decomposing solutions with dry nitrogen to remove the gaseous products. A first-order dependence of decomposition rate on "analytical nitrite" was found, the rate constants being dependent on the solvent acid composition.

scholarly journals INFLUENCE OF TEMPERATURE AND PH ON THE DECOMPOSITION KINETICS OF PERACETIC ACID IN AQUEOUS SOLUTIONS

2014 ◽  
Vol 44 (3) ◽  
pp. 195-201
Author(s):  
L. KUNIGK ◽  
S. P. GALIZIA ◽  
R.T. K. SHIKISHIMA ◽  
R. GEDRAITE ◽  
C. H. JURKIEWICZ
Keyword(s):  
Activation Energy ◽  
Aqueous Solutions ◽  
Peracetic Acid ◽  
Food Industry ◽  
Decomposition Kinetics ◽  
Order Reaction ◽  
Influence Of Temperature ◽  
First Order ◽  
All Solutions ◽  
Kinetics Of

Peracetic acid (PAA) is a strong oxidant used by the food industry as a sanitizer, in medical area as a disinfectant and by the textiles and paper industries as a bleacher. Its decomposition rate is an important parameter in these applications. The main purpose of this paper is to study the decomposition kinetics of PAA between 25 and 45 °C in solutions with pH 3.11, 5.0 and 7.0. The decomposition of PAA is a first-order reaction for all solutions and temperatures studied. The rate constants were between 2.08·10-3 and 9.44·10-3 h-1 (pH 3.11), between 2.61·10-3 and 16.69·10-3 h-1 (pH 5.0) and between 7.50·10-3 and 47.63·10-3 h-1 (pH 7.0). The activation energy of PAA decomposition in aqueous solutions are 58.36 and 72.89 kJ·mol-1 when pH was 3.11 and 5.0, respectively.

scholarly journals The Removal of Uranium and Thorium from Aqueous Solutions Onto by-pass Cement Dust (BCD)

2016 ◽  
Vol 11 (2) ◽  
pp. 105
Author(s):  
Ali Omnia M. ◽  
El-Kashif H.H. ◽  
Sayed S.A. ◽  
Shalabi M.E.H.
Keyword(s):  
Aqueous Solutions ◽  
Thermodynamic Parameters ◽  
Freundlich Isotherm ◽  
Adsorption Behavior ◽  
Energy Of Activation ◽  
Optimum Conditions ◽  
Cement Dust ◽  
Initial Concentration ◽  
First Order ◽  
Batch Technique

<p>The adsorption behavior of uranium and thorium from aqueous solutions by By-pass cement dust (BCD) has been investigated by a batch technique. The uranium and thorium adsorption on BCD was studied as a function of initial concentration, weight of BCD, pH, shaking time and temperature. The uptake of uranium and thorium at the determined optimum conditions follows Freundlich isotherm. The adsorption control of both thorium and uranium are first order and uptake energy of activation E<sub>a</sub> =10 and 15 kJ/mol for thorium and uranium respectively. Thermodynamic parameters such as ΔH<sup>o</sup>, ΔS<sup>o</sup> and ΔG<sup>o</sup> were also investigated.</p>

Eigenanalysis of the Coupled First-Order Isomerization Reactions of the Bis[(S)-alaninato]dinitrocobaltate(III) Ion

1989 ◽  
Vol 42 (10) ◽  
pp. 1647
Author(s):  
JK Beattie ◽  
MB Celap ◽  
MT Kelso ◽  
SM Nesic
Keyword(s):  
Differential Equations ◽  
Aqueous Solutions ◽  
Rate Constants ◽  
Chromatographic Separation ◽  
Reaction Scheme ◽  
Isomerization Reaction ◽  
Geometric Isomers ◽  
First Order ◽  
Kinetics Of ◽  
First Order Differential Equations

Three of the five possible geometric isomers of the bis[(S)-alaninato] dinitrocobaltate (III) ion isomerize to the stable fourth isomer by a series of first-order reactions. The fifth isomer is not observed. The kinetics of the isomerizations in neutral, aqueous solutions between 65 and 95 C have been studied by chromatographic separation of the isomers. The data were fitted by eigenanalysis of the coupled first-order differential equations. The results are consistent with a reaction scheme requiring five rate constants, kxy, where xy represents isomerization from isomer x to isomer y. lsomer A is the Λ-(-)589-cis-NO2/cis-N/cis-O complex; isomer B the trans-NO2/cis-N/cis-O complex; isomer C the trans-NO2/trans-N/trans-O complex; and isomer D is the mixture of both diastereomers of the cis-NO2/trans-N/cis-O complex that is formed from B and C. The rate constants required are kAB, kbc , kBD , kCB and kCD . The same reaction scheme had been found previously for the analogous glycinato complexes, but the activation energies differ. For the valine and leucine analogues, the rate constants and activation enthalpies for the first isomerization reaction, represented by kAB, are similar to that of the alanine complex.

scholarly journals Removal efficiency of phenol by ozonation process with calcium peroxide from aqueous solutions

2021 ◽  
Vol 11 (2) ◽  
Author(s):  
Zhila Honarmandrad ◽  
Neda Javid ◽  
Mohammad Malakootian
Keyword(s):  
Aqueous Solutions ◽  
Environmental Protection Agency ◽  
Calcium Peroxide ◽  
First Order ◽  
The Us ◽  
Phenol Decomposition ◽  
Endothermic Process ◽  
Kinetics Of ◽  
Ozonation Process ◽  
Coefficient Method

AbstractPhenol has been introduced as a priority pollutant by the US Environmental Protection Agency. Advanced oxidation processes (AOPs) are one of the most efficient methods for removal of non-degradable organic pollutants in aqueous solutions. The removal efficiencies of phenol and COD under optimal conditions pH = 3, phenol concentration = 5 mg/L, CaO2 concentration = 0.025 mg/L, temperature 25 °C, 1 g/min ozonation rate and contact time = 90 min in synthetic and real samples (Zarand coal washing factory in Kerman) were obtained 97.8%, 87% and 80%, 65.4%, respectively. The kinetics of phenol decomposition follows from the pseudo-first-order equation. Thermodynamic studies show that phenol decomposition with ozonation and calcium peroxide is an endothermic process. The use of ozonation process with calcium peroxide is an efficient method and can be recommended as a coefficient method for the removal of phenol.

Kinetics and Mechanism of Ligand Substitutionin Triglycinatovanadium(III) by EDTA and NTA in Aqueous Solutions

1994 ◽  
Vol 59 (5) ◽  
pp. 1077-1085
Author(s):  
Yasuhisa Ikeda ◽  
Refat M. Hassan ◽  
Moustafa M. Abd El-Fattah ◽  
Yul Y. Park ◽  
Hiroshi Tomiyasu
Keyword(s):  
Ionic Strength ◽  
Aqueous Solutions ◽  
Kinetic Parameters ◽  
Ligand Substitution ◽  
Reactive Species ◽  
Constant Ionic Strength ◽  
Substitution Reactions ◽  
First Order ◽  
Kinetics Of ◽  
Mechanism Of The Reaction

The kinetics of ligand substitution reactions in triglycinatovanadium(III) by EDTA and NTA as multidentate ligands were investigated at a constant ionic strength of 2.5 mol dm-3 spectrophotometrically. The substitutions were second-order reactions, first order in both reactants. Their rate could be expressed in the form r = k [V(gly)3] [EDTA(NTA)] where k = 2.62 .10-2 and 6.96 .10-2 mol-1 dm3 s-1 at 25 °C for EDTA and NTA, respectively. The results obtained at different pH indicated that [H2edta]2- and [Hnta]2- ions were the most reactive species in the substitution. Kinetic parameters have been evaluated and a tentative mechanism of the reaction has been proposed.

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