scholarly journals Pesticide production wastewater treatment by Electro-Fenton using Taguchi experimental design

2021 ◽  
Author(s):  
Thanh Luu Pham ◽  
Faten Boujelbane ◽  
Hiep Nghia Bui ◽  
Hieu Trung Nguyen ◽  
Xuan-Thanh Bui ◽  
...  
Keyword(s):  
Kinetic Model ◽  
Density Functional ◽  
Reaction Kinetic ◽  
Polynomial Regression ◽  
Treated Wastewater ◽  
Order Kinetic ◽  
Functional Theory ◽  
First Order ◽  
Toc Removal ◽  
Order Kinetic Model

Abstract In this study, the electro – Fenton (EF) method was applied to remove total organic carbon (TOC) from the pesticide production wastewater containing tricyclazole (TC). Statistical Taguchi method was used to optimize the treatment performance. Analysis of variance (ANOVA) indicated that the polynomial regression model fitted experimental data with R2 of 0.969. The optimal conditions for eliminating 75.4% TOC and 93.7% TC, were 0.2 mM of Fe2+, 990 mg/L of Na2SO4, 180 min of reaction time at pH 3 with 2.22 mA/cm2 of current density. The removal of TC present in the wastewater followed the first-order reaction kinetic model (R2 = 0.993); while that was the second-order kinetic model in the case of the TOC removal (R2 = 0.903). In addition, the experimental results and theory approaches (density functional theory and natural bond orbital calculations) also showed that the C-N bond breaking and nitrate ions cleavage ammonia. Acute toxicity of the pesticide wastewater after treatment (PWAT) on microcrustacean showed that the treated wastewater still exhibited high toxicity against D. magna, with LC50 values of 3.84%, 2.68%, 2.05%, and 1.78% at 24 h, 48 h, 72 h, and 96 h, respectively.

Characteristics and kinetics of hexavalent chromium reduction by gallic acid in aqueous solutions

2015 ◽  
Vol 71 (11) ◽  
pp. 1694-1700 ◽  
Author(s):  
ZiFang Chen ◽  
YongSheng Zhao ◽  
Qin Li
Keyword(s):  
Kinetic Model ◽  
Gallic Acid ◽  
Hexavalent Chromium ◽  
Ph Value ◽  
Order Kinetic ◽  
First Order ◽  
Molar Ratios ◽  
Wide Range ◽  
Order Kinetic Model ◽  
Pseudo First Order

Gallic acid (GA) is a naturally occurring plant polyphenol compound. Experiments were conducted to study the kinetics and effects of pH, temperature, irradiation, and initial hexavalent chromium (Cr(VI)) concentration on Cr(VI) reduction by GA. Results indicated that Cr(VI) could be reduced to chromium oxide (Cr(III)) with GA in a wide range of pH values from 2.0 to 8.5. The reaction followed a pseudo-first-order kinetic model with respect to Cr(VI) and GA in acid conditions (pH 2.0–5.0). However, the reaction did not follow the pseudo-first-order kinetic model at pH 6.5 and 8.5. Removal efficiencies and reaction rate constants of Cr(VI) significantly increased with decreasing pH value and increasing temperature. The effect of irradiation on Cr(VI) reduction increased with increasing pH, and irradiation improved the removal efficiency of Cr(VI) by 11.29% at pH 6.5. At pH 2.0, nearly all molar ratios of GA required for the reduction of Cr(VI) were 1:2 (±0.1) under different initial Cr(VI) concentrations; however, the molar ratios of GA required for the reduction of Cr(VI) were 1:1.29, 1:1.43, and 1:1.69, respectively, when the initial Cr(VI) concentrations were 10, 25, and 50 mg/L at pH 5.5.

scholarly journals Kinetic Analysis for Agglomeration-Flotation of Finely Ground Chalcopyrite: Comparison of First Order Kinetic Model and Experimental Results

2020 ◽  
Vol 61 (10) ◽  
pp. 1940-1948
Author(s):  
Vothy Hornn ◽  
Mayumi Ito ◽  
Ryosuke Yamazawa ◽  
Hiromasa Shimada ◽  
Carlito Baltazar Tabelin ◽  
...  
Keyword(s):  
Kinetic Model ◽  
Kinetic Analysis ◽  
Experimental Results ◽  
Order Kinetic ◽  
First Order ◽  
Order Kinetic Model

scholarly journals CHARACTERISTICS OF ASCORBIC ACID RELEASE FROM TPP-CROSSLINKED CHITOSAN/ALGINATE POLYELECTROLYTE COMPLEX MEMBRANES

2018 ◽  
Vol XXIII ◽  
pp. 76-87 ◽  
Author(s):  
Magdalena Gierszewska ◽  
Jadwiga Ostrowska-Czubenko ◽  
Ewelina Chrzanowska
Keyword(s):  
Ascorbic Acid ◽  
Kinetic Model ◽  
Polyelectrolyte Complex ◽  
Zero Order ◽  
Order Kinetic ◽  
Initial Burst ◽  
First Order ◽  
Order Kinetic Model ◽  
Acid Release ◽  
Release Data

Chitosan/alginate polyelectrolyte complex membranes (Ch/Alg) additionally cross-linked with tripolyphosphate (TPP) and containing ascorbic acid (AA) were prepared. The dynamic swelling behaviour of Ch/Alg/TPP and ascorbic acid release from the membrane were characterised in different buffer solutions. It has been found that the pH of the buffer solution affects the swelling and release behaviour of AA. Ascorbic acid release, observed over a period of 360 min, exhibited a biphasic pattern, characterised by a fast initial burst release, followed by a slow, sustained release. Different mathematical models were used to study the kinetics and transport mechanism of AA from Ch/Alg/TPP hydrogels. Drug release data were fitted to the zero order kinetic model and first order kinetic model. To characterise the drug mechanism, the release data were fitted to the Higuchi and Korsmeyer-Peppas equations. The initial burst AA release followed zero order kinetics and was quasi-Fickian in nature. The second step of AA release followed first order kinetics.

Sorption of Pb2+ on Mg-Al-Fe Hydrotalcite-Like Compounds

2012 ◽  
Vol 573-574 ◽  
pp. 86-91
Author(s):  
Xue Feng Liang ◽  
Wan Guo Hou ◽  
Ying Ming Xu ◽  
Lin Wang ◽  
Yue Bing Sun
Keyword(s):  
Kinetic Model ◽  
Rate Increase ◽  
Freundlich Isotherm ◽  
Order Kinetic ◽  
Sorption Mechanism ◽  
Chemical Binding ◽  
First Order ◽  
Maximum Sorption ◽  
Order Kinetic Model ◽  
Pseudo First Order

Hydrotalcite-like compounds containing Mg2+, Al3+ and Fe3+ with a constant M2+/M3+ ratio but varying Al3+/Fe3+ ratios have been prepared. The effects of iron contents on the structural and sorption of Pb2+ by Mg-Al-Fe HTlc samples were investigated. The maximum sorption amounts were about 88-201 mg/g for Mg-Al-Fe HTlc samples. The sorption isotherm and kinetic processes can be described with Freundlich isotherm and pseudo first order kinetic model, respectively. The sorption amounts and rate increase with the increase of iron contents in HTlc samples. The sorption mechanism of Pb2+ on Mg-Al-Fe HTlcs may be the surface-induced precipitation and chemical binding adsorption.

Mathematical Description of Trifluralin Degradation in Soil

Weed Science ◽  
1989 ◽  
Vol 37 (4) ◽  
pp. 604-608 ◽  
Author(s):  
Carlos C. Reyes ◽  
Robert L. Zimdahl
Keyword(s):  
Kinetic Model ◽  
Rate Equations ◽  
Differential Rate ◽  
Order Kinetic ◽  
First Order ◽  
Degradation Data ◽  
Order Kinetic Model ◽  
Soil Site ◽  
Biexponential Model ◽  
Better Than

Degradation of trifluralin in four soils, each represented at four sites, under field conditions was determined quantitatively and described mathematically. A biexponential equation that resulted from integration of first-order and second-order differential rate equations described degradation data better than the first-order kinetic model for 15 of 25 soil-site combinations. Biexponential model regression coefficients indicated extent of degradation and that degradation is rapid at initially high trifluralin concentrations but slows as concentration decreases. The first-order kinetic model initially underestimated but ultimately overestimated degradation of trifluralin, thereby inferring that a first-order half-life is inadequate for predicting trifluralin persistence.

Effects of ultraviolet intensity and wavelength on the photolysis of triclosan

2007 ◽  
Vol 55 (1-2) ◽  
pp. 209-216 ◽  
Author(s):  
H.-S. Son ◽  
S.-B. Choi ◽  
K.-D. Zoh ◽  
E. Khan
Keyword(s):  
Kinetic Model ◽  
Hydroxyl Radicals ◽  
Direct Photon ◽  
Order Kinetic ◽  
First Order ◽  
Photodegradation Rate ◽  
Order Kinetic Model ◽  
Pseudo First Order ◽  
First Time ◽  
Subordinate Role

The effects of ultraviolet (UV) intensity and wavelength on triclosan (TCS) photodegradation kinetic, efficiency, mechanisms and pathway were studied. The TCS photodegradation followed the pseudo-first order kinetic model at all UV intensities examined at the wavelengths of 254 and 365 nm and the photodegradation rate increased with increasing UV intensity. TCS photodegradation efficiencies of 90 to 98% and 79 to 90% were obtained at the wavelengths of 254 and 365 nm, respectively. TCS was degraded mainly by photon induced hydroxyl radicals while the direct photon reaction with TCS played a subordinate role. Chlorophenol, dichlorophenol and phenol were the intermediates detected in all experiments conducted. Dibenzodichloro-p-dioxin and dibenzo-p-dioxin were observed as the intermediates only at lower UV intensities investigated at the wavelength of 365 nm. Based on these intermediates, a complete TCS photolysis pathway was proposed for the first time.

Fabrication and Photocatalytic Decolorization Performance of ZnO

2011 ◽  
Vol 396-398 ◽  
pp. 823-826
Author(s):  
Jie Cheng ◽  
Jian Zhang Li ◽  
Jun Bo Zhong ◽  
Wei Hu
Keyword(s):  
Methyl Orange ◽  
Kinetic Model ◽  
Uv Irradiation ◽  
Precipitation Method ◽  
Order Kinetic ◽  
First Order ◽  
Photocatalytic Decolorization ◽  
Langmuir Hinshelwood Mechanism ◽  
Order Kinetic Model ◽  
Pseudo First Order

Paralled flaw precipitation method has been employed to synthesize nanostructured ZnO. The prepared photocatalyst was characterized by BET, XRD. The paper reveals that Methyl Orange (MO) can be decolorized effectively in ZnO suspension system under UV irradiation. The optimal loading of photocatalyst in our experimental condition for the decolorization of MO is 1g/L. The present study, on the base of Langmuir-Hinshelwood mechanism, illustrates that the decolorization reaction is a pseudo first order kinetic model with the limiting rate constant of 8.48×10-2 mgL-1min-1 and equilibrium adsorption constant 0.335 L/mg, respectively.

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