scholarly journals Kinetics of dechlorination of atrazine using tin (SnII) at neutral pH conditions

2020 ◽  
Vol 3 (1) ◽  
pp. 49
Author(s):  
Vijay Kumar ◽  
Simranjeet Singh
Keyword(s):  
Aqueous Media ◽  
Spectrometric Analysis ◽  
First Order ◽  
Neutral Ph ◽  
First Order Kinetics ◽  
Condi Tions ◽  
Ph Conditions ◽  
Pseudo First Order ◽  
Reaction Constants ◽  
Kinetics Of

Atrazine is a broad spectrum herbicide of triazine family. It is a chlorine-containing molecule and it can persist in environment. Chemical and biochemical techniques are the main techniques used to decompose the chemicals. In pre-sent study, the dechlorination of atrazine (Atr) via reaction with Sn(II) ion under aqueous media at neutral pH condi-tions was studied. The observed dechlorinated metabolite was 4-Ethylamino-6-isopropylamino-[1,3,5]triazin-2-ol. Identification of dechlorinated product of Atr was performed by using spectroscopic (FTIR) and mass (ESI-MS) spectrometric analysis. The kinetics of the dechlorination of Atr was measured by using pseudo-first order kinetics. The observed reaction constants was, kobs = 6.11x10-2 (at 430 mg/ L of Atr), and kobs = 6.14 x10-2 (at 215 mg/ L of Atr). The calculated half-life (t1/2) period was, t1/2 = 0.204 d (at 430 mg/ L of Atr), and t1/2 = 0.205 d (at 215 mg/ L of Atr).

The kinetics and the mechanism of oxidative decarboxylation of benzilic acid by acidic permanganate (stopped-flow technique) — An autocatalytic study

2004 ◽  
Vol 82 (9) ◽  
pp. 1372-1380 ◽  
Author(s):  
Sairabanu A Farokhi ◽  
Sharanappa T Nandibewoor
Keyword(s):  
Activation Parameters ◽  
Oxidative Decarboxylation ◽  
Two Stage ◽  
First Order ◽  
First Order Kinetics ◽  
Stage Process ◽  
Benzilic Acid ◽  
Reaction Constants ◽  
Kinetics Of ◽  
Good Agreement

The kinetics of the oxidation of benzilic acid by potassium permanganate in an acidic medium were studied spectrophotometrically. The reaction followed a two-stage process, wherein both stages of the reaction followed first-order kinetics with respect to permanganate ion and benzilic acid. The rate of the reaction increased with an increase in acid concentration. Autocatalysis was observed by one of the products, i.e., manganese(II). A composite mechanism involving autocatalysis has been proposed. The activation parameters of the reaction were calculated and discussed and the reaction constants involved in the mechanisms were calculated. There is a good agreement between the observed and calculated rate constants under different experimental conditions.Key words: oxidation, autocatalysis, benzilic acid, two-stage kinetics.

Parameters Effect on Photocatalytic Reduction Kinetics of Bromate in Aqueous Dispersion of TiO2

2013 ◽  
Vol 779-780 ◽  
pp. 1658-1665
Author(s):  
Rong Shu Zhu ◽  
Fei Tian ◽  
Ling Ling Zhang ◽  
Ling Min Yu
Keyword(s):  
Aqueous Dispersion ◽  
Zero Order ◽  
Photocatalytic Reduction ◽  
Reduction Kinetics ◽  
First Order ◽  
First Order Kinetics ◽  
Zero Order Kinetics ◽  
Experimental Parameters ◽  
Pseudo First Order ◽  
Kinetics Of

This paper studied the photocatalytic reduction kinetics of bromate in aqueous dispersion of TiO2 and investigated the effects of experimental parameters, including initial concentration of BrO3-, pH, TiO2 dosage, anion and cation. The results indicate that the process of photocatalytic reduction of bromate follows a zero-order kinetics. In all the investigated experimental parameters, the initial bromate concentration, pH and anion have great effect on the photocatalytic reduction kinetics. The processes of photocatalytic reduction of bromate show the pseudo first-order kinetics at initial bromate concentration of 0.39 μmolL-1, pH=5.0, or in presence of HCO3-/CO32-, NO3-, SO42-, respectively.

Kinetics and mechanism of dehydrochlorination of N-aryl-C-ethoxycarbonylformohydrazidoyl chlorides

1986 ◽  
Vol 64 (5) ◽  
pp. 871-875 ◽  
Author(s):  
Ahmad S. Shawali ◽  
Hassan A. Albar
Keyword(s):  
Rate Constants ◽  
Water Solution ◽  
Chloride Ion ◽  
Order Conditions ◽  
Rate Law ◽  
First Order ◽  
Rate Determining Step ◽  
Pseudo First Order ◽  
Reaction Constants ◽  
Kinetics Of

The kinetics of triethylamine (TEA) catalyzed deydrochlorination of a series of N-aryl-C-ethoxycarbonylformohydrazidoyl chlorides 1a–m have been studied under pseudo-first-order conditions in 4:1 (v/v) dioxane–water solution at 30 °C. For all compounds studied, the kinetics followed the rate law: kobs = k2 (TEA). The values of the overall second-order rate constants for the studied compounds were correlated by the equation: log k2 = 0.533σ−-0.218. The results are compatible with a mechanism involving a fast reversible deprotonation step leading to the anion of 1, followed by rate-determining step involving the loss of the chloride ion from the anion. The reaction constants of these two steps were estimated to be 0.845 and −0.312, respectively.

Kinetics of hydrolysis of aromatic mono- and disulfonyl chlorides

1987 ◽  
Vol 65 (9) ◽  
pp. 2263-2267 ◽  
Author(s):  
Przemyslaw Sanecki ◽  
Edward Rokaszewski
Keyword(s):  
Aqueous Acetic Acid ◽  
Polarographic Method ◽  
Acid System ◽  
First Order ◽  
First Order Kinetics ◽  
Kinetics Of Hydrolysis ◽  
Consecutive Reactions ◽  
Pseudo First Order ◽  
Kinetics Of ◽  
Hydrolysis Of

A continuous polarographic method of recording instantaneous concentrations of —SO2Cl groups in an aqueous acetic acid system containing CH3CO2Na has been elaborated. Ten model monosulfonyl chlorides underwent hydrolysis according to pseudo-first order kinetics (20% H2O, 80% v.v. CH3CO2H, 0.5 mol × dm−3 CH3CO2Na). Plots of hydrolysis for seven disulfonyl dichlorides with different number of —CH3 groups have been determined. Pseudo-first order rate constants for two consecutive reactions of hydrolysis (k1 and k2) have been computed and the influence of —SO2Cl and [Formula: see text] groups on the reactivity of the second group —SO2Cl has been discussed. The mechanism of nucleophilic substitution has also been discussed.

Oxidation of the mercurous ion by peroxidase

1986 ◽  
Vol 64 (5) ◽  
pp. 969-972 ◽  
Author(s):  
Donald C. Wigfield ◽  
Season Tse
Keyword(s):  
Elemental Mercury ◽  
Order Rate Constant ◽  
Kinetics Of Oxidation ◽  
First Order ◽  
Order Rate ◽  
First Order Kinetics ◽  
Cold Vapour ◽  
Pseudo First Order ◽  
Kinetics Of ◽  
Mercurous Ion

The kinetics of oxidation of the mercurous ion by peroxidase have been measured by following the disappearance of mercurous ion using cold-vapour atomic absorption spectroscopy. Pseudo-first-order kinetics are observed with respect to mercurous ion, and the pseudo-first-order rate constants are linearly related to peroxidase concentration, showing first-order dependence on peroxidase. This behaviour is identical to oxidation of elemental mercury, and the second-order rate constant, 1.44 × 104 M−1 s−1 at 23 °C, is also, within experimental error, the same as that for elemental mercury oxidation. The data are interpreted in terms of peroxidase-induced disproportionation of the mercurous dimer, followed by two-electron oxidation of zero-valent mercury.

Electron-Transfer Reactions in Non-Aqueous Media. VI. A Temperature-Dependence Study of the Reduction of cis-[CoCl2(en)2]+ by Iron(II) in Me2SO

1979 ◽  
Vol 32 (10) ◽  
pp. 2275 ◽  
Author(s):  
L Spiccia ◽  
DW Watts
Keyword(s):  
Electron Transfer ◽  
Temperature Dependence ◽  
Transfer Process ◽  
Iron Atom ◽  
Aqueous Media ◽  
Transfer Reactions ◽  
Electron Transfer Process ◽  
First Order ◽  
Pseudo First Order ◽  
Kinetics Of

The kinetics of the reduction of cis-[CoCl2(en)2] � (en = ethylenediamine) by iron(II) in Me2SO have been studied at four temperatures. The rate law has the form d[CoIII]/dt = kK [COIII][FeII]/(1+K[FII]) The pseudo-first-order rate constants determined at high [Fell] have been resolved into k and K, and their independent temperature dependence has been studied. The results are totally consistent with an inner-sphere electron-transfer process in which the precursor complex contains a double bridge using both the cis-chloro ligands and in which the iron atom is octahedrally coordinated.

Degradation Kinetics of Reactive Brilliant Red X-3B Dye by UV/Mn2+/H2O2/Micro-Aeration

2012 ◽  
Vol 441 ◽  
pp. 549-554
Author(s):  
Ying Jie Cai ◽  
Xiao Jun Yang ◽  
Dong Sheng Xia ◽  
Qing Fu Zeng
Keyword(s):  
Degradation Rate ◽  
Ph Value ◽  
Degradation Kinetics ◽  
H2o2 Concentration ◽  
Kinetics Equation ◽  
Linear Least Squares ◽  
First Order ◽  
First Order Kinetics ◽  
Pseudo First Order ◽  
Kinetics Of

Abstract. Degradation of reactive brilliant red X-3B (X-3B) by a UV/Mn2+/H2O2/micro- aeration method was investigated. The influencing factors of degradation of X-3B including UV irradiation, aeration, pH value, H2O2 concentration and X-3B concentration were examined. The results show that X-3B was effectively degraded by the UV/Mn2+/H2O2/micro-aeration method. The degradation rate of X-3B was obtained from weighted linear least squares analysis of the experimental data, and accorded with the pseudo-first order kinetics equation.

Kinetics of tartrazine photodegradation by UV/H2O2 in aqueous solution

2014 ◽  
Vol 68 (1) ◽  
Author(s):  
Petruta Oancea ◽  
Viorica Meltzer
Keyword(s):  
H2o2 Concentration ◽  
Reaction Intermediates ◽  
Original Design ◽  
Experimental Conditions ◽  
First Order ◽  
Toc Removal ◽  
First Order Kinetics ◽  
Photodegradation Rate ◽  
Pseudo First Order ◽  
Kinetics Of

AbstractIn the present work, kinetics of tartrazine decay by UV irradiation and H2O2 photolysis, and the removal of total organic carbon (TOC) under specific experimental conditions was explored. Irradiation experiments were carried out using a photoreactor of original design with a low-pressure Hg vapour lamp. The photodegradation rate of tartrazine was optimised with respect to the H2O2 concentration and temperature for the constant dye concentration of 1.035 × 10−5 M. Tartrazine degradation and the removal of TOC followed the pseudo-first-order kinetics. The much higher k obs value for tartrazine degradation (7.91 × 10−4 s−1) as compared with the TOC removal (2.3 × 10−4 s−1) confirmed the presence of reaction intermediates in the solution.

Receptor Mediated Uptake Of Fibrin Monomer

1981 ◽  
Author(s):  
J R Shainoff ◽  
B N Dardik ◽  
S R Gonda
Keyword(s):  
Cell Surface ◽  
Factor Xiiia ◽  
Adsorptive Capacity ◽  
First Order ◽  
High Affinity ◽  
First Order Kinetics ◽  
Period 2 ◽  
Order Chemical Reaction ◽  
Pseudo First Order ◽  
Kinetics Of

Electron microscopy of macrophages exposed to fibrinogen solutions containing dissolved fibrin that was labelled with heme-octapeptide for cytochemical detection indicated that 1) the fibrin became adsorbed in a monomeric rather than aggregated form at saturating levels on the cell surface over a 2-5 min. period, 2) the adsorbed fibrin was fully internalized by vesicular uptake and fused with lysosomal bodies over a subsequent 30-60 min, and 3) a loss of adsorptive capacity of the cell surface for uptake of more fibrin accompanied internalization of fibrin. The uptake of fibrin in monomeric form despite its existence in aggregated but dissociable form in solution indicated that the fibrin was being adsorbed by a receptor with affinity for the same sites that participate in aggregation, sites that are exposed by release of fibrinopeptide A. Removal of fibrinopeptide B itself does not induce high affinity uptake. By analogy to the loss of adsorptive capacity accompanying internalization of the fibrin by macrophages, clearance of monomer from the circulation also appears to depend on a consumable receptor in that initial rates of clearance of 125I-labelled monomer at high dosages (>1 mg/kg) follow kinetics of a 2nd order chemical reaction, while pseudo-first order kinetics apply with low dosages (<0.3 mg/kg). A requirement of dissociability of monomer from soluble complexes for rapid uptake is indicated by observation that the poorly dissociable form of fibrin lacking both fibrinopeptides A and B is cleared from the circulation at a very slow rate compared to fibrin lacking A alone. Importance of dissociability is indicated also by observation that injection of Factor XIIIa inhibits uptake to a degree comparable to removal of both A and B. The demonstration of monomer uptake indicates that clearance of fibrin may precede its deposition in aggregated form. It is suggested that the rapid but saturable uptake of monomer may proceed independently of phagocytosis of macroaggregates.

Some observations on the kinetics of the Jaffé reaction for creatinine.

1977 ◽  
Vol 23 (9) ◽  
pp. 1527-1530 ◽  
Author(s):  
R M Shoucri ◽  
M Pouliot
Keyword(s):  
Rate Constants ◽  
Kinetic Data ◽  
Serum Samples ◽  
First Order ◽  
Order Rate ◽  
First Order Kinetics ◽  
Pseudo First Order ◽  
Kinetics Of

Abstract The Jaffé reaction for creatinine assay appears to follow pseudo-first-order kinetics; first-order rate constants are different for different samples. Rate constants for 10 different serum samples varied from a low value of 0.0040 +/- 0.0003 s-1 to 0.0084 +/- 0.0008 s-1. We describe an approach for determining first-order rate constants from kinetic data and discuss the effects of the above observations on the mathematical formulations required for reliable kinetic determinations of creatinine.

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