scholarly journals EFFECT OF Cr(VI) IONS ON THE EFFECTIVENESS OF CHLOROPHENOL PHOTODEGRADATION

2010 ◽  
Vol 4 (3) ◽  
pp. 156-160
Author(s):  
Endang Tri Wahyuni ◽  
Ngatidjo Hadipranoto ◽  
Iqmal Tahir ◽  
Bambang Haryo Gatut Tamtama
Keyword(s):  
Gas Chromatography ◽  
Reaction Time ◽  
Order Reaction ◽  
Solution Ph ◽  
First Order ◽  
Uv Lamp ◽  
Reaction Constants ◽  
Respective Rate ◽  
Closed Reactor

In order to solve environmental problems due to chlorophenol compound and which is hazardous and carcinogenic, the effect of Cr(VI) ions on the chlorophenol photodegradation effectiveness has been evaluated. Photodegradation process was carried out in a closed reactor by batch sistem, by exposing the UV lamp into a solution containing chlorophenol and Cr(VI) ions for a period of time. Then the solution was analyzed by gas chromatography for determination of the residual chlorophenol concentration. In this research, the influences of reaction time, Cr(VI) ions concentration, and solution pH on the photodegradation results were also evaluated. The research results indicated that the effectiveness of the photodegradation increases when ion Cr(VI) was added. The improvement of the effectiveness is proportional with the increase of the concentration of Cr(VI) added. The effectiveness of the photodegradation is also influenced by solution pH, and the highest is reached at pH < 2. Chlorophenol photodegradation follows first order reaction. The respective rate reaction constants for chlorophenol photodegradation in the absence and in the presence of Cr(VI) ions are 4.91x 10-2 and 11.41x 10-2 hours-1   Keywords: photodegradation, chlorophenol, Cr(VI) ion

Leaching Kinetics of Atrazine and Inorganic Chemicals in Tilled and Orchard Soils

2014 ◽  
Vol 28 (2) ◽  
pp. 231-237 ◽  
Author(s):  
Lech W. Szajdak ◽  
Jerzy Lipiec ◽  
Anna Siczek ◽  
Artur Nosalewicz ◽  
Urszula Majewska
Keyword(s):  
Reaction Rate ◽  
Inorganic Compounds ◽  
Model Performance ◽  
Order Reaction ◽  
First Order Reaction ◽  
Order Kinetic ◽  
Time Data ◽  
First Order ◽  
Concentration Changes ◽  
Reaction Constants

Abstract The aim of this study was to verify first-order kinetic reaction rate model performance in predicting of leaching of atrazine and inorganic compounds (K+1, Fe+3, Mg+2, Mn+2, NH4 +, NO3 - and PO4 -3) from tilled and orchard silty loam soils. This model provided an excellent fit to the experimental concentration changes of the compounds vs. time data during leaching. Calculated values of the first-order reaction rate constants for the changes of all chemicals were from 3.8 to 19.0 times higher in orchard than in tilled soil. Higher first-order reaction constants for orchard than tilled soil correspond with both higher total porosity and contribution of biological pores in the former. The first order reaction constants for the leaching of chemical compounds enables prediction of the actual compound concentration and the interactions between compound and soil as affected by management system. The study demonstrates the effectiveness of simultaneous chemical and physical analyses as a tool for the understanding of leaching in variously managed soils.

scholarly journals Municipal Leachate Treatment by Fenton Process: Effect of Some Variable and Kinetics

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Mohammad Ahmadian ◽  
Sohyla Reshadat ◽  
Nader Yousefi ◽  
Seyed Hamed Mirhossieni ◽  
Mohammad Reza Zare ◽  
...  
Keyword(s):  
Reaction Time ◽  
Color Removal ◽  
Molar Ratio ◽  
Order Kinetic ◽  
Fenton Process ◽  
Solution Ph ◽  
Leachate Treatment ◽  
First Order ◽  
Order Kinetic Model ◽  
Better Than

Due to complex composition of leachate, the comprehensive leachate treatment methods have been not demonstrated. Moreover, the improper management of leachate can lead to many environmental problems. The aim of this study was application of Fenton process for decreasing the major pollutants of landfill leachate on Kermanshah city. The leachate was collected from Kermanshah landfill site and treated by Fenton process. The effect of various parameters including solution pH, Fe2+and H2O2dosage, Fe2+/H2O2molar ratio, and reaction time was investigated. The result showed that with increasing Fe2+and H2O2dosage, Fe2+/H2O2molar ratio, and reaction time, the COD, TOC, TSS, and color removal increased. The maximum COD, TOC, TSS, and color removal were obtained at low pH (pH: 3). The kinetic data were analyzed in term of zero-order, first-order, and second-order expressions. First-order kinetic model described the removal of COD, TOC, TSS, and color from leachate better than two other kinetic models. In spite of extremely difficulty of leachate treatment, the previous results seem rather encouraging on the application of Fenton’s oxidation.

Evaluation of a modified alcohol dehydrogenase assay for the determination of ethanol in blood.

1982 ◽  
Vol 28 (10) ◽  
pp. 2125-2127 ◽  
Author(s):  
A Poklis ◽  
M A Mackell
Keyword(s):  
Gas Chromatography ◽  
Reaction Time ◽  
Alcohol Dehydrogenase ◽  
Correlation Coefficients ◽  
Least Square ◽  
Standard Curve ◽  
Analytical Recovery ◽  
Sigma Chemical ◽  
Enzymic Assay

Abstract We evaluated a new alcohol dehydrogenase (EC 1.1.1.1) enzymic assay (ADH-glycine, Sigma Chemical Co.) for the determination of ethanol in blood. This assay differs from the manufacturer's previous assay (ADH-pyrophosphate) in that glycine replaces pyrophosphate as the buffer and hydrazine replaces semicarbazide as the trapping agent. The standard curve for the assay was linear over blood ethanol concentrations of 0.50-5.00 g/L. The reaction time of the assay was 10 min. At 1.00 g/L within-run and between-run CVs were 3.96% (n = 20) and 4.01% (n = 20), respectively. Mean analytical recovery of ethanol added to whole blood at 0.50-5.00 g/L was 99.7% (SD 2.6%). We performed 100 consecutive clinical and forensic determinations by the ADH-glycine assay, the ADH-pyrophosphate assay, and gas chromatography. Correlation coefficients of the results by least-square linear regression were 0.995 for ADH-pyrophosphate vs ADH-glycine, and 0.990 for gas chromatography vs ADH-glycine. The major advantage of the ADH-glycine assay over the ADH-pyrophosphate assay is the shorter reaction time, 10 min vs 30 min.

scholarly journals Determination of Malathion, Coumaphos, and Fluvalinate Residues in Honey by Gas Chromatography with Nitrogen–Phosphorus or Electron Capture Detectors

2000 ◽  
Vol 83 (1) ◽  
pp. 178-182 ◽  
Author(s):  
Urania Menkissoglu-Spiroudi ◽  
Grigorios C Diamantidis ◽  
Vassiliki E Georgiou ◽  
Andreas T Thrasyvoulou
Keyword(s):  
Gas Chromatography ◽  
Electron Capture ◽  
High Selectivity ◽  
Order Model ◽  
First Order ◽  
Quantitation Limit ◽  
Coefficients Of Variation ◽  
Electron Capture Detectors ◽  
Nitrogen Phosphorus

Abstract A rapid, reliable, and inexpensive extraction method was developed to determine acaricide residues in honey by gas chromatography (GC) with nitrogen–phosphorus (NP) or electron capture (EC) detectors. Because of the high selectivity of the NP detector, no interfering peaks were present and no cleanup was necessary. A simple cleanup step is proposed for the GC–ECD analysis. Recoveries from spiked honey samples ranged from 79 to 94.4%, with coefficients of variation of 0.3–18.5%. The quantitation limit obtained was 0.015 mg/kg for malathion, 0.020 mg/kg for coumaphos, and 0.005 mg/kg for fluvalinate. The method was used to determine the disappearance of malathion and coumaphos residues from honey samples collected from beehives treated with these acaricides. The disappearance of both acaricides was rapid and followed a first-order model for the duration of the experiment.

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 Preparation of wrapped nZVI particles and their application for the degradation of trichloroethylene (TCE) in aqueous solution

2015 ◽  
Vol 5 (3) ◽  
pp. 335-343 ◽  
Author(s):  
Wenjing Fan ◽  
Yue Cheng ◽  
Shuzhen Yu ◽  
Xiaofeng Fan ◽  
Yaqian Deng
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solution ◽  
Methyl Cellulose ◽  
Order Reaction ◽  
Phase Reaction ◽  
Solution Ph ◽  
First Order ◽  
Structure And Morphology ◽  
Transmission Electron ◽  
Optimal Ph

Three types of wrappped nanoscale zero-valent iron (W-nZVI) with different coatings including agar, starch, and carboxyl methyl cellulose, were synthesized using a rheological phase reaction method. The structure and morphology of W-nZVI particles were characterized by scanning electron microscopy and transmission electron microscopy. Batch degradation experiments exhibited that W-nZVI dosage, initial trichloroethylene (TCE) concentration and solution pH had significant effects on TCE dechlorination. Experimental results proved that the highest dechlorination efficiency was obtained within 320 minutes for 10 mg/L of TCE at the optimal pH of 5.0 and W-nZVI dosage of 0.5 g/L. Kinetic study revealed that TCE dechlorination by W-nZVI in aqueous solution obeyed the quasi-first-order reaction kinetics. The product after the reaction could be easily separated by the permanent magnet for re-use.

scholarly journals Studi Kinetika Efektifitas Minyak Daun Cengkeh (Syzigium aromaticum) Sebagai Antifungi Candida albicans

2019 ◽  
Vol 6 (2) ◽  
pp. 107-114
Author(s):  
Rustam Musta ◽  
Laily Nurliana
Keyword(s):  
Candida Albicans ◽  
Reaction Order ◽  
Kinetic Studies ◽  
Order Reaction ◽  
Minimum Concentration ◽  
Initial Concentration ◽  
Fungal Activity ◽  
Reaction Constants ◽  
Anti Fungal

Kinetic studies effectiveness clove leaf (Syzigium aromaticum) oil as antifungal Candida albicans have been done. The study have purpose to determine the reaction order, reaction constants (k) and relationship the concentration of clove leaf (Syzigium aromaticum) oil every time (At) with the initial concentration of of clove (Syzigium aromaticum) oil (Ao) and time (t) and equipped determination of the minimum concentration of clove leaf (Syzigium aromaticum)oil effective anti-fungus Candida albicans. The results shows the anti-fungal activity clove leaf (Syzigium aromaticum) oil on Candida albicans for each variation of the concentration 100%, 75%, 50% and 25% are 14.2 mm, 12.2 mm, 10.8 mm and 10.4 mm respectively. Reaction order as antifungal of the clove leaf (Syzigium aromaticum) oil on Candida albicans is 0.2112 with k = 5.0594. The minimum concentration of clove leaf (Syzigium aromaticum) oil as anti-fungal Candida albicans is 17.86%.

Sign in / Sign up

Export Citation Format

Share Document