Laboratory Simulation Study of Photo-Degradation Process of Fenvalerate in Aqueous Solution

2013 ◽  
Vol 312 ◽  
pp. 886-892
Author(s):  
Yan Ru Liang ◽  
Yu Yun Wen ◽  
Xiao Yan Hong ◽  
Zhen Bin Gong ◽  
Wen Quan Li
Keyword(s):  
Aqueous Solution ◽  
Reaction Rate ◽  
Organic Molecules ◽  
Spectral Characteristics ◽  
Degradation Process ◽  
Laboratory Simulation ◽  
Fluorescent Substance ◽  
Photo Degradation ◽  
Small Organic Molecules ◽  
Degradation Reaction

A laboratory-made the efficient photochemical degradation experimental device, combined with high performance liquid chromatography-tandem diode array detector device (DAD), fluorescence detector (FLD), mass spectrometer detector (MS), research fenvalerate its photo degradation. The structure of the spectral characteristics is the product, photo degradation reaction kinetics of degradation products, suggesting fenvalerate light chemical degradation process in an aqueous solution. The spectral characteristics of fenvalerate under ultraviolet light can be degraded into smaller organic molecules; maternal and main product have strong UV - visible absorption, fenvalerate are weakly fluorescent substance in the aqueous solution. The major products are strong fluorescent substance. Almost no effect The photo degradation kinetic data show fenvalerate photo degradation in an aqueous solution to approximate a reaction of the reaction; pesticide initial concentration, the pH value of the aqueous solution of pesticides photo degradation reaction rate; To accelerate the increase of salinity, light intensity fenvalerate in aqueous photo degradation reaction rate; significant influence of small organic molecules, with the type of small organic molecules.

Photo-Degradation of Cypermethrin in Aqueous Solution Studied by HPLC-DAD

2013 ◽  
Vol 634-638 ◽  
pp. 1044-1048
Author(s):  
Yan Ru Liang ◽  
Zhen Bin Gong ◽  
Wen Quan Li
Keyword(s):  
Aqueous Solution ◽  
High Performance ◽  
Degradation Products ◽  
Degradation Process ◽  
Mass Spectrometric ◽  
Photochemical Degradation ◽  
Pseudo First Order Reaction ◽  
Photo Degradation ◽  
Mass Spectrometric Detector ◽  
Degradation Reaction

The photo-degradation process of cypermethrin in aqueous solution was studied using the laboratory-built photochemical degradation device and commercial high performance liquid chromatography (HPLC) with ultraviolet-visible absorbance detector and mass spectrometric detector. Spectrometric characteristics of cypermethrin and its main degradation products suggest that cypermethrin could be photo-degradated and converted into smaller molecular under ultraviolet irradiation. The photo-degradation reaction of cypermethrin in aqueous solution is approximately pseudo-first-order reaction. Light strength, pH and salinity have significant effects on the photo-degradaiton reaction of cypermethrin. Mass spectrometric results show that cypermethrin pesticide can be degraded into new and easily photochemical degrading products through the removal of chlorine.

Covalent capture of supramolecular species in an aqueous solution of water-miscible small organic molecules

2019 ◽  
Vol 21 (20) ◽  
pp. 10477-10487 ◽  
Author(s):  
Yongchao Yao ◽  
Chuanqi Li ◽  
Fangqin Liu ◽  
Pengxiang Zhao ◽  
Zhongwei Gu ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Organic Molecules ◽  
Small Organic Molecules

Covalent capture was used to study the structure of the supramolecular species formed in an aqueous solution of water-miscible organic molecules.

Effect of Environmental Factors of Mannanase on Konjac Glucomannan Molecular Dimension

2011 ◽  
Vol 689 ◽  
pp. 308-314
Author(s):  
Xiao Yan Long ◽  
Xue Gang Luo ◽  
Ju Bai ◽  
Jia Feng Zhu
Keyword(s):  
Aqueous Solution ◽  
Molecular Weight ◽  
Reaction Time ◽  
Environmental Factors ◽  
Weight Distribution ◽  
Degradation Process ◽  
Konjac Glucomannan ◽  
Molecular Dimension ◽  
Degradation Reaction ◽  
Theoretical Foundations

The environmental factors of mannanase konjac glucomannan (KGM) have been investigated in aqueous solution. Molecular weight (Mw) and molecular weight distribution (WMD) of the degraded KGM were measured by GPC. During the degradation process, the molecular weight of the enzymatic products decreases with reaction time, degradation reaction combining two reactions processed with different orders, while WMD broadens at first and then becomes narrow. The reduction of molecular dimension of KGM was lowered with temperature increase, but WMD increases. WMD was reduced with concentration of enzyme increase, but the reduction of molecular dimension of KGM was insignificant in the range of 2.0~6.5 u.mL-1of mannanase concentration. The results show that molecular dimension of KGM could be controlled by soft changes of reaction environment, dimension of KGM molecule could be decreased more than 100 times so as to obtain oligosaccharides, which offers the reference to reliable theoretical foundations and practical ground in exploiting KGM potential function and activity.

scholarly journals Photodegradation of 2, 4, 5, 6-Tetrachloroisophthalonitrile (Chlorothalonil) by Visible and Ultraviolet Light in the Presence of ZnO and TiO2

2019 ◽  
Vol 7 (3) ◽  
pp. 79-88
Author(s):  
Raad N. Salih ◽  
Salah-Aldin Naman
Keyword(s):  
Aqueous Solution ◽  
Reaction Order ◽  
Product Formation ◽  
Light Sources ◽  
Photo Degradation ◽  
First Order ◽  
Rate Of Reaction ◽  
Degradation Reaction ◽  
Uv Visible ◽  
Arrhenius Factor

photocatalytic degradation of fungicides (chlorothalonil) in suspension aqueous solution with semiconductors (tio­2, zno) and without semiconductor has been investigated. the influence of different parameters such as light sources, the concentration of fungicides, type of semiconductors and temperature were studied by uv-visible spectrophotometer at 232 and 254 nm. the degradation reaction order spectra of chlorothalonil were determined which first order at 232 nm and second order at 254 nm. in addition, the rate constant, arrhenius factor and energy of activation can be estimated for both peaks. moreover, conductivity of chlorothalonil has been recorded during the photo-degradation and the rate of reaction also has been determined that dependent on product formation.

QUBEKit: Automating the Derivation of Force Field Parameters from Quantum Mechanics

2019 ◽  
Author(s):  
Joshua Horton ◽  
Alice Allen ◽  
Leela Dodda ◽  
Daniel Cole
Keyword(s):  
Quantum Mechanics ◽  
Force Field ◽  
Organic Molecules ◽  
Force Fields ◽  
Liquid Density ◽  
Small Organic Molecules ◽  
Automated Generation ◽  
Energy Of Hydration ◽  
Novel Method ◽  
Force Field Parameters

<div><div><div><p>Modern molecular mechanics force fields are widely used for modelling the dynamics and interactions of small organic molecules using libraries of transferable force field parameters. For molecules outside the training set, parameters may be missing or inaccurate, and in these cases, it may be preferable to derive molecule-specific parameters. Here we present an intuitive parameter derivation toolkit, QUBEKit (QUantum mechanical BEspoke Kit), which enables the automated generation of system-specific small molecule force field parameters directly from quantum mechanics. QUBEKit is written in python and combines the latest QM parameter derivation methodologies with a novel method for deriving the positions and charges of off-center virtual sites. As a proof of concept, we have re-derived a complete set of parameters for 109 small organic molecules, and assessed the accuracy by comparing computed liquid properties with experiment. QUBEKit gives highly competitive results when compared to standard transferable force fields, with mean unsigned errors of 0.024 g/cm3, 0.79 kcal/mol and 1.17 kcal/mol for the liquid density, heat of vaporization and free energy of hydration respectively. This indicates that the derived parameters are suitable for molecular modelling applications, including computer-aided drug design.</p></div></div></div>

QUBEKit: Automating the Derivation of Force Field Parameters from Quantum Mechanics

2019 ◽  
Author(s):  
Joshua Horton ◽  
Alice Allen ◽  
Leela Dodda ◽  
Daniel Cole
Keyword(s):  
Quantum Mechanics ◽  
Force Field ◽  
Organic Molecules ◽  
Force Fields ◽  
Liquid Density ◽  
Small Organic Molecules ◽  
Automated Generation ◽  
Energy Of Hydration ◽  
Novel Method ◽  
Force Field Parameters

<div><div><div><p>Modern molecular mechanics force fields are widely used for modelling the dynamics and interactions of small organic molecules using libraries of transferable force field parameters. For molecules outside the training set, parameters may be missing or inaccurate, and in these cases, it may be preferable to derive molecule-specific parameters. Here we present an intuitive parameter derivation toolkit, QUBEKit (QUantum mechanical BEspoke Kit), which enables the automated generation of system-specific small molecule force field parameters directly from quantum mechanics. QUBEKit is written in python and combines the latest QM parameter derivation methodologies with a novel method for deriving the positions and charges of off-center virtual sites. As a proof of concept, we have re-derived a complete set of parameters for 109 small organic molecules, and assessed the accuracy by comparing computed liquid properties with experiment. QUBEKit gives highly competitive results when compared to standard transferable force fields, with mean unsigned errors of 0.024 g/cm3, 0.79 kcal/mol and 1.17 kcal/mol for the liquid density, heat of vaporization and free energy of hydration respectively. This indicates that the derived parameters are suitable for molecular modelling applications, including computer-aided drug design.</p></div></div></div>

Photo-degradation of monoazo dye blue 13 using advanced oxidation process

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Aqueous Solution ◽  
Advanced Oxidation Process ◽  
Oxidation Process ◽  
High Energy ◽  
Uv Exposure ◽  
H2o2 Concentration ◽  
Oxidizing Agent ◽  
Photo Degradation ◽  
High Energy Radiation ◽  
Uv Lamp

The high energy radiation overcome the bonding of solute in a solution and H2O2 acts as an oxidizing agent and generates a free radical in the solution which results in photo-degradation by converting the solute in to simple form and resultantly, colored substance under the effect of photo-degradation becomes colorless. The photo-degradation of monoazo dye Blue 13 in an aqueous solution was investigated using a laboratory scale UV lamp in the presence of H2O2 and for maximum degradation of dye, the independent parameter UV power, UV exposure time, pH and H2O2 concentration were optimized. It was found that neither UV in the presence of H2O2 is able to degrade Blue 13 under optimum condition. The results revealed that the use of both UV and H2O2 have pronounced effect on the discoloration of dyes which could be used for management of textile effluents contain waste dyes.

Studying dispersed and rheological properties of hydrocarbon-containing acid emulsions and their efficiency in removing asphalt-resin-paraffin deposits

2020 ◽  
pp. 128-139
Author(s):  
M. Yu. Shumakher ◽  
V. V. Konovalov ◽  
A. P. Melnikov
Keyword(s):  
Aqueous Solution ◽  
Hydrochloric Acid ◽  
Rheological Properties ◽  
Reaction Rate ◽  
Experimental Studies ◽  
Efficient Removal ◽  
Reservoir Properties ◽  
Hydrocarbon Solvents ◽  
Formation Zone ◽  
Effect Of The Composition

Currently, the treatment of the bottomhole formation zone with acidic compositions is one of the most common methods to intensify the oil inflow. The use of various modified acid compositions increases the efficiency of acid treatments on the bottomhole formation zone. Acid compositions, including those containing hydrocarbon solvents, which contribute to more efficient removal of organic colmatants, affect the reaction rate of the reagent with the rock and processing equipment, change the reservoir properties, etc.The article presents the results of experimental studies, which are aimed at establishing the effect of the composition of hydrocarbon-containing acidic emulsions consisting of an aqueous solution of hydrochloric acid, toluene and Neonol AF 9-10 on their dispersed and rheological properties, as well as their efficiency in removing paraffin deposits.

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