Reduction of 4-nitrophenol to 4-aminophenol using Pt/HKUST-1 catalyst

2021 ◽  
Vol 10 (4) ◽  
pp. 110-116
Author(s):  
Ha Bui Thi Thanh ◽  
Duong Le Van ◽  
Hung Ta Ngoc ◽  
Hai Dinh Thi Thanh ◽  
Duong Pham Dai ◽  
...  
Keyword(s):  
Reaction Rate ◽  
Good Stability ◽  
High Concentration ◽  
Catalyst Sample

The catalyst Pt/HKHUST-1 was used for synthesis 4-aminophenol (4-AP) by reducsion 4-nitrophenol (4-NP). Factors that affected to the reaction were tested: ratio 4-NP/NaBH4, temperature and time of the reaction. Changing the ratio of 4-NP/NaBH4 in the direction of increasing NaBH4, the reaction rate increases. However, it is acceptable to reduce the reaction rate when synthesizing with high concentration of reactants. The 4-AP synthesis is performed with ratio 4-NP/NaBH4 = 1/5, suitable time and temperature for this reaction is 60 minutes and 15 oC. The catalyst sample containing 2% Pt on HKUST-1 material was used to synthesize 4-AP with the yield of 65.3% (average 64.2%), the catalyst has good stability, can reused many times. The purity of 4-AP after refining was 99 %.

Reduction of 4-nitrophenol to 4-aminophenol using Pt/HKUST-1 catalyst

2021 ◽  
Vol 11 (1) ◽  
pp. 111-117
Author(s):  
Ha Bui Thi Thanh ◽  
Duong Le Van ◽  
Hung Ta Ngoc ◽  
Hai Dinh Thi Thanh ◽  
Duong Pham Dai ◽  
...  
Keyword(s):  
Reaction Rate ◽  
Good Stability ◽  
High Concentration ◽  
Catalyst Sample

The catalyst Pt/HKHUST-1 was used for synthesis 4-aminophenol (4-AP) by reducsion 4-nitrophenol (4-NP). Factors that affected to the reaction were tested: ratio 4-NP/NaBH4, temperature and time of the reaction. Changing the ratio of 4-NP/NaBH4 in the direction of increasing NaBH4, the reaction rate increases. However, it is acceptable to reduce the reaction rate when synthesizing with high concentration of reactants. The 4-AP synthesis is performed with ratio 4-NP/NaBH4 = 1/5, suitable time and temperature for this reaction is 60 minutes and 15 oC. The catalyst sample containing 2% Pt on HKUST-1 material was used to synthesize 4-AP with the yield of 65.3% (average 64.2%), the catalyst has good stability, can reused many times. The purity of 4-AP after refining was 99 %.

scholarly journals Catalysis of Rice Straw Hydrolysis by the Combination of Immobilized Cellulase fromAspergillus nigeronβ-Cyclodextrin-Fe3O4Nanoparticles and Ionic Liquid

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Po-Jung Huang ◽  
Ken-Lin Chang ◽  
Jung-Feng Hsieh ◽  
Shui-Tein Chen
Keyword(s):  
Ionic Liquid ◽  
Rice Straw ◽  
Reaction Rate ◽  
Magnetic Particles ◽  
Initial Reaction Rate ◽  
Initial Reaction ◽  
High Concentration ◽  
Solid Reaction ◽  
Immobilized Cellulase ◽  
Hydrolysis Of

Cellulase fromAspergillus nigerwas immobilized ontoβ-cyclodextrin-conjugated magnetic particles by silanization and reductive amidation. The immobilized cellulase gained supermagnetism due to the magnetic nanoparticles. Ninety percent of cellulase was immobilized, but the activity of immobilized cellulase decreased by 10%. In this study, ionic liquid (1-butyl-3-methylimidazolium chloride) was introduced into the hydrolytic process because the original reaction was a solid-solid reaction. The activity of immobilized cellulase was improved from 54.87 to 59.11 U g immobilized cellulase−1at an ionic liquid concentration of 200 mM. Using immobilized cellulase and ionic liquid in the hydrolysis of rice straw, the initial reaction rate was increased from 1.629 to 2.739 g h−1 L−1. One of the advantages of immobilized cellulase is high reusability—it was usable for a total of 16 times in this study. Compared with free cellulase, magnetized cellulase can be recycled by magnetic field and the activity of immobilized cellulase was shown to remain at 85% of free cellulase without denaturation under a high concentration of glucose (15 g L−1). Therefore, immobilized cellulase can hydrolyze rice straw continuously compared with free cellulase. The amount of harvested glucose can be up to twentyfold higher than that from the hydrolysis by free cellulase.

Studying rheological properties and reactivity of acid solutions with thickening additives

2021 ◽  
pp. 40-54
Author(s):  
M. B. Dorfman ◽  
A. A. Sentemov ◽  
I. P. Belozerov
Keyword(s):  
Rheological Properties ◽  
Acid Treatment ◽  
Reaction Rate ◽  
Acid Solutions ◽  
High Permeability ◽  
High Concentration ◽  
Sweep Efficiency ◽  
Reservoir Properties ◽  
Slowing Down ◽  
Lignosulfonic Acid

This article is the result of studies of rheological properties and reactivity of acid solutions of technical lignosulfonate, decationized lignosulfonic acid, and hydrochloric acid with the addition of lignosulfonate. Compositions that include lignosulfonate can be used as displacement agents in the development of watered layers with inhomogeneous reservoir properties. The use of thickening additives in acid solutions solves several problems. Slowing the reaction rate will allow the acid flow to leak in the reservoir deeper, with saving of acid capacity. The height viscosity of the compositions increases the sweep efficiency of the bottomhole zone by acid treatment. Due to the fact that thickening additives in the compositions have a high concentration, selective isolation of highly permeable areas of the reservoir can be realized, which, in turn, contributes to the formation of new pore channels.We evaluated the reactivity of acid solutions with thickening additives in the interaction with carbonate samples. The presence of technical lignosulfonate in an acid solution reduces the dissolution rate of samples. Slowing down the reaction rate will allow the acid composition to form long channels of high permeability, which, in turn, increases the efficiency of acid treatment.

Design of Impinging Stream-Cavitations and Micro-Electrolysis Reactor and Treatment of High Concentration Wastewater

2013 ◽  
Vol 781-784 ◽  
pp. 1994-1997 ◽  
Author(s):  
Hao Wu ◽  
Fu Bao Li ◽  
Qin Li ◽  
Wei Sha
Keyword(s):  
Reaction Time ◽  
Reaction Rate ◽  
Cod Removal ◽  
High Concentration ◽  
Air Compressor ◽  
First Order ◽  
First Order Kinetics

A micro-electrolysis reactor combined with the technology of impinging stream-cavitations drum was designed. Then it was used in the treatment of high concentration wastewater. Under the conditions of reaction time is 60 min, ratio of iron to carbon is 1 and the pressure of the air compressor is 8Mpa, the COD and chromaticity could remove 95.7% and 85.9% respectively. The biodegradability was improved obviously with 0.55 of BOD5/COD. The determinations of kinetics under the best conditions show that, the mode of COD removal basically conforms to the rule of first order kinetics. The reaction rate in our reactor was faster than only micro-electrolysis or only cavitations obviously. The conjunction of impinging stream-cavitations and micro-electrolysis has good synergism and facilitation.

Review of Treatment Methods for Fracturing Flowback Fluid

2014 ◽  
Vol 881-883 ◽  
pp. 659-662
Author(s):  
Fu Bao Li ◽  
Jun Jie Yang ◽  
Qin Li ◽  
Hao Wu
Keyword(s):  
Waste Water ◽  
Wastewater Treatment ◽  
Reaction Kinetics ◽  
Organic Waste ◽  
Reaction Rate ◽  
High Concentration ◽  
Fracturing Fluid ◽  
Treatment Methods ◽  
Organic Wastewater ◽  
At Home

Through analyzing and comparing the treatment of fracturing fluid flowback at home and abroad, it can be found that fluid derived organic waste water can be handled by micro electrolysis economically and efficiently. But there are also some shortages of traditional micro electrolysis. So this paper discusses a new micro-electrolysis technology, namely cavitation-impinging stream electrolysis technology which has several advantages in high concentration organic wastewater treatment. The technology can not only solve the problems that the passivation of process and the plugged equipment in the treatment of fracturing fluid flowback fluid by traditional micro electrolysis, but also can better promote the reaction from the reaction kinetics with the help of Coupling application about cavitation and impinging stream technology, so as to realize the purpose of improving the reaction rate and efficiency.

scholarly journals Contribution of Dissolved Oxygen to Methylene Blue Decomposition by Hybrid Advanced Oxidation Processes System

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Heon Lee ◽  
Sung Hoon Park ◽  
Byung Hoon Kim ◽  
Sun-Jae Kim ◽  
Sang-Chai Kim ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Dissolved Oxygen ◽  
Advanced Oxidation Processes ◽  
Reaction Rate ◽  
Organic Pollutant ◽  
High Concentration ◽  
Decomposition Rate Constant ◽  
Experimental Conditions ◽  
Solution Treated ◽  
Do Concentration

Experimental results of photocatalysis under high dissolved oxygen (DO) concentration conditions are reported. Methylene blue was used as the organic pollutant to be degraded by a novel microwave/UV/DO/TiO2photocatalyst hybrid system. The degradation rate increased with TiO2nanoparticle dosages and DO concentration. However, inhibition of photocatalysis due to bubbles produced by DO generator was also observed. When the DO generator was used to increase the DO concentration in the pollutant solution treated by the microwave-assisted UV-TiO2photocatalysis, the decomposition rate constant was highest among all the experimental conditions tested in this study. This result demonstrated that high concentration of DO can enhance the photocatalytic reaction rate by causing a synergistic effect of constituent techniques.

The Photocatalytic Activity of Bi20TiO32 for Degradation of Organic Pollutants in Different Water Quality

2012 ◽  
Vol 610-613 ◽  
pp. 586-589
Author(s):  
Xu Hui Sun ◽  
Xi Yu ◽  
Lin Sun ◽  
Lei Wang
Keyword(s):  
Water Quality ◽  
Photocatalytic Activity ◽  
Light Intensity ◽  
Organic Pollutants ◽  
Reaction Rate ◽  
High Concentration

In order to test the photocatalytic activity of Bi20TiO32under different conditions, experiments were done to compare its performance for degrading organic pollutants in water. The results are as following. Higher light intensity will increase the reaction rate. Ions in water will affect adversely the photoreaction. Temperature has little effect on the reaction. High concentration of H2O2helps to degrade organic pollutants in water.

scholarly journals Prospects for Engineering Biophysical CO2 Concentrating Mechanisms into Land Plants to Enhance Yields

2020 ◽  
Vol 71 (1) ◽  
pp. 461-485 ◽  
Author(s):  
Jessica H. Hennacy ◽  
Martin C. Jonikas
Keyword(s):  
Genetic Engineering ◽  
Reaction Rate ◽  
Photosynthetic Activity ◽  
Crop Yields ◽  
Land Plants ◽  
High Concentration ◽  
Primary Producers ◽  
Cyanobacteria And Algae ◽  
Molecular Components ◽  
Co2 Concentrating Mechanisms

Although cyanobacteria and algae represent a small fraction of the biomass of all primary producers, their photosynthetic activity accounts for roughly half of the daily CO2 fixation that occurs on Earth. These microorganisms are able to accomplish this feat by enhancing the activity of the CO2-fixing enzyme Rubisco using biophysical CO2 concentrating mechanisms (CCMs). Biophysical CCMs operate by concentrating bicarbonate and converting it into CO2 in a compartment that houses Rubisco (in contrast with other CCMs that concentrate CO2 via an organic intermediate, such as malate in the case of C4 CCMs). This activity provides Rubisco with a high concentration of its substrate, thereby increasing its reaction rate. The genetic engineering of a biophysical CCM into land plants is being pursued as a strategy to increase crop yields. This review focuses on the progress toward understanding the molecular components of cyanobacterial and algal CCMs, as well as recent advances toward engineering these components into land plants.

Cytomembrane Preservation in Tissue Dehydrated Only With Glutaraldehyde and Epon 812 Resin

1973 ◽  
Vol 31 ◽  
pp. 320-321
Author(s):  
Daniel C. Pease
Keyword(s):  
Diffraction Pattern ◽  
X Ray Diffraction ◽  
High Concentration ◽  
Unpublished Study ◽  
X Ray ◽  
Sectioned Material

A previous study demonstrated that tissue could be successfully infiltrated with 50% glutaraldehyde, and then subsequently polymerized with urea to create an embedment which retained cytomembrane lipids in sectioned material. As a result, the 180-190 Å periodicity characteristic of fresh, mammalian myelin was preserved in sections, as was a brilliant birefringence, and the capacity to bind OsO4 vapor in the hydrophobic bilayers. An associated (unpublished) study, carried out in co-operation with Drs. C.K. Akers and D.F. Parsons, demonstrated that the high concentration of glutaraldehyde (and urea) did not significantly alter the X-ray diffraction pattern of aldehyde-fixed, myelin. Thus, by itself, 50% glutaraldehyde has little effect upon cytomembrane systems and can be used with confidence for the first stages of dehydration.

Effects of carbamylcholine on chick embryo aggregate retina cell cultures

1988 ◽  
Vol 46 ◽  
pp. 350-351
Author(s):  
Glenn M. Cohen ◽  
Radharaman Ray
Keyword(s):  
Cell Cultures ◽  
Single Cells ◽  
Retinal Cell ◽  
Cell Aggregates ◽  
High Concentration ◽  
In Ovo ◽  
Sterile Culture ◽  
Retinal Tissue ◽  
Synaptic Junctions ◽  
And Control

Retinal,cell aggregates develop in culture in a pattern similar to the in ovo retina, forming neurites first and then synapses. In the present study, we continuously exposed chick retinal cell aggregates to a high concentration (1 mM) of carbamylcholine (carbachol), an acetylcholine (ACh) analog that resists hydrolysis by acetylcholinesterase (AChE). This situation is similar to organophosphorus anticholinesterase poisoning in which the ACh level is elevated at synaptic junctions due to inhibition of AChE, Our objective was to determine whether continuous carbachol exposure either damaged cholino- ceptive neurites, cell bodies, and synaptic elements of the aggregates or influenced (hastened or retarded) their development.The retinal tissue was isolated aseptically from 11 day embryonic White Leghorn chicks and then enzymatically (trypsin) and mechanically (trituration) dissociated into single cells. After washing the cells by repeated suspension and low (about 200 x G) centrifugation twice, aggregate cell cultures (about l0 cells/culture) were initiated in 1.5 ml medium (BME, GIBCO) in 35 mm sterile culture dishes and maintained as experimental (containing 10-3 M carbachol) and control specimens.

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