Equilibrium and kinetics of the dinuclear complex formation between N,N′-ethylenebis(salicylideneiminato)copper(II) and metal(II,I) ions in acetonitrile

SummaryGelchromatography column scanning has been used to study the fractions of 99mTc-pertechnetate, 99mTcchelate and reduced hydrolyzed 99mTc in preparations of 99mTc-EDTA(Sn) and 99mTc-DTPA(Sn). The labelling yield of 99mTc-EDTA(Sn) chelate was as high as 90—95% when 100 μmol EDTA · H4 and 0.5 (Amol SnCl2 was incubated with 10 ml 99mTceluate for 30—60 min at room temperature. The study of the influence of the pH-value on the fraction of 99mTc-EDTA shows that pH 2.8—2.9 gave the best labelling yield. In a comparative study of the labelling kinetics of 99mTc-EDTA(Sn) and 99mTc- DTPA(Sn) at different temperatures (7, 22 and 37°C), no significant influence on the reduction step was found. The rate constant for complex formation, however, increased more rapidly with increased temperature for 99mTc-DTPA(Sn). At room temperature only a few minutes was required to achieve a high labelling yield with 99mTc-DTPA(Sn) whereas about 60 min was required for 99mTc-EDTA(Sn). Comparative biokinetic studies in rabbits showed that the maximum activity in kidneys is achieved after 12 min with 99mTc-EDTA(Sn) but already after 6 min with 99mTc-DTPA(Sn). The long-term disappearance of 99mTc-DTPA(Sn) from the kidneys is about five times faster than that for 99mTc-EDTA(Sn).

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Adsorption Equilibrium and Kinetics of CO2 and H2O on Activated Carbon

Journal of Inorganic Materials ◽

10.3724/sp.j.1077.2012.00139 ◽

2012 ◽

Vol 27 (2) ◽

pp. 139-145 ◽

Cited By ~ 4

Author(s):

Dong XU ◽

Jun ZHANG ◽

Gang LI ◽

Penny XIAO ◽

Paul WEBLEY ◽

...

Keyword(s):

Activated Carbon ◽

Adsorption Equilibrium ◽

Equilibrium And Kinetics ◽

Adsorption Equilibrium And Kinetics ◽

Kinetics Of

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Thermodynamic and detailed kinetic study of the formation of orthophthalaldehyde-agmatine complex by fluorescence intensities

Journal of Analytical Science & Technology ◽

10.1186/s40543-020-00238-2 ◽

2020 ◽

Vol 11 (1) ◽

Author(s):

Khémesse Kital ◽

Moumouny Traoré ◽

Diégane Sarr ◽

Moussa Mbaye ◽

Mame Diabou Gaye Seye ◽

...

Keyword(s):

Complex Formation ◽

Thermodynamic Parameters ◽

Initial Rate ◽

Reaction Medium ◽

Standard Entropy ◽

Step Size ◽

Formation Reaction ◽

Different Temperatures ◽

Kinetics Of ◽

Complex Formation Process

Abstract The aim of this work is to determine the thermodynamic parameters and the kinetics of complex formation between orthophthalaldehyde (OPA) and agmatine (AGM) in an alkaline medium (pH 13). Firstly, the association constant (Ka) between orthophthalaldehyde and agmatine was determined at different temperatures (between 298 K and 338 K) with a step size of 10 K. Secondly, the thermodynamic parameters such as standard enthalpy (ΔH°), standard entropy (ΔS°),and Gibbs energy (∆G) were calculated, where a positive value of ΔH° (+45.50 kJ/mol) was found, which shows that the reaction is endothermic. In addition, the low value of ΔS°(+0.24 kJ/mol) indicates a slight increase in the disorder in the reaction medium. Furthermore, the negative values of ΔG between −35.62 kJ/mol and −26.02 kJ/mol show that the complex formation process is spontaneous. Finally, the parameters of the kinetics of the reaction between OPA and AGM were determined as follows: when the initial concentration of AGM (5 × 10−6 M) is equal to that of the OPA, the results show that the reaction follows an overall 1.5 order kinetics with an initial rate of 5.1 × 10−7Mmin−1 and a half-life of 8.12 min. The partial order found in relation to the AGM is 0.8. This work shows that the excess of OPA accelerates the formation reaction of the complex.

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A comprehensive study on equilibrium and kinetics of morpholine extraction from aqueous stream with CA in toluene: Experimental evaluation, extraction model and parametric optimization employing desirability function

Chemical Engineering Research and Design ◽

10.1016/j.cherd.2018.03.027 ◽

2018 ◽

Vol 133 ◽

pp. 243-254 ◽

Cited By ~ 2

Author(s):

Alka Kumari ◽

B. Karuna ◽

B. Satyavathi

Keyword(s):

Experimental Evaluation ◽

Parametric Optimization ◽

Desirability Function ◽

Equilibrium And Kinetics ◽

Extraction Model ◽

Kinetics Of ◽

Comprehensive Study

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Silica Removal from a Paper Mill Effluent by Adsorption on Pseudoboehmite and γ-Al2O3

Water ◽

10.3390/w13152031 ◽

2021 ◽

Vol 13 (15) ◽

pp. 2031

Author(s):

Ruben Miranda ◽

Isabel Latour ◽

Angeles Blanco

Keyword(s):

Paper Mill ◽

Ph Adjustment ◽

Paper Mill Effluent ◽

Kinetics Studies ◽

Silica Removal ◽

Industrial Water Use ◽

Optimum Ph ◽

Initial Ph ◽

Equilibrium And Kinetics ◽

Kinetics Of

Effluent reuse is a common practice for sustainable industrial water use. Salt removal is usually carried out by a combination of membrane processes with a final reverse osmosis (RO). However, the presence of silica limits the RO efficiency due to its high scaling potential and the difficulty of cleaning the fouled membranes. Silica adsorption has many advantages compared to coagulation and precipitation at high pHs: pH adjustment is not necessary, the conductivity of treated waters is not increased, and there is no sludge generation. Therefore, this study investigates the feasibility of using pseudoboehmite and its calcination product (γ-Al2O3) for silica adsorption from a paper mill effluent. The effect of sorbent dosage, pH, and temperature, including both equilibrium and kinetics studies, were studied. γ-Al2O3 was clearly more efficient than pseudoboehmite, with optimal dosages around 2.5–5 g/L vs. 7.5–15 g/L. The optimum pH is around 8.5–10, which fits well with the initial pH of the effluent. The kinetics of silica adsorption is fast, especially at high dosages and temperatures: 80–90% of the removable silica is removed in 1 h. At these conditions, silica removal is around 75–85% (<50 mg/L SiO2 in the treated water).

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