scholarly journals Effect of KOH Pretreatment on Lignocellulosic Waste for the Reduction of Nitrobenzene to Aniline without Metal

2020 ◽  
Vol 12 (11) ◽  
pp. 4665
Author(s):  
Sarra Tadrent ◽  
Anissa Khelfa ◽  
Christophe Len
Keyword(s):  
Lignocellulosic Biomass ◽  
Present Method ◽  
Metal Catalyst ◽  
Protic Solvent ◽  
Optimal Conditions ◽  
Lignocellulosic Waste ◽  
Experimental Conditions

A green reduction of nitrobenzene to aniline was carried out using lignocellulosic biomass as a hydrogen source in a subcritical polar protic solvent, such as water and alcohol. The method is simple to implement, inexpensive, and easily applicable on a larger scale. The present method does not demand elaborated experimental conditions nor any metal catalyst. Optimal conditions provided aniline with a 90% yield by reduction of nitrobenzene in the presence of sawdust impregnated by KOH in subcritical methanol at 240 °C for 6 h.

A Simple Method for Estimation of Lipoxygenase and Cyclo-Oxygenase Pathways in Human Platelets - the Use of Thiobarbituric Acid Reaction

1980 ◽  
Vol 44 (02) ◽  
pp. 111-114 ◽  
Author(s):  
Hiroshi Takayama ◽  
Minoru Okuma ◽  
Haruto Uchino
Keyword(s):  
Time Course ◽  
Normal Values ◽  
Human Platelet ◽  
Thiobarbituric Acid ◽  
Human Platelets ◽  
Optimal Conditions ◽  
Experimental Conditions ◽  
Simple Method ◽  
Acid Reaction ◽  
Optimal Ph

SummaryTo develop a simple method for estimation of platelet lipoxygenase (PLO) and cyclo-oxygenase (PCO) pathways, the arachidonic acid (AA) metabolism of human platelet was investigated under various experimental conditions by the use of the thiobarbituric acid (TBA) reaction and a radioisotope technique. A TBA-reactive substance different from malondialdehyde (MDA) via PCO pathway was detected and shown to be derived from the PLO pathway. Since the optimal pH and time course of its formation were different from those of MDA formation via PCO pathway, PLO and PCO pathways were estimated by quantitating the TBA-reactive substances produced by the incubation of AA either with aspirin-treated platelets or with untreated ones, respectively, each under optimal conditions. Normal values expressed in terms of nmol MDA/108 platelets were 1.17±0.34 (M±SD, n = 31) and 0.79±0.15 (n = 31) for PLO and PCO pathways, respectively.

scholarly journals Treatment of High-Strength Animal Industrial Wastewater Using Photo-Assisted Fenton Oxidation Coupled to Photocatalytic Technology

Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1553 ◽  
Author(s):  
Jae Hong Park ◽  
Dong Seok Shin ◽  
Jae Kwan Lee
Keyword(s):  
Light Intensity ◽  
Removal Efficiency ◽  
Industrial Wastewater ◽  
Uv Light ◽  
High Strength ◽  
Cod Removal ◽  
Fenton Oxidation ◽  
Optimal Conditions ◽  
Experimental Conditions ◽  
Animal Wastewater

Animal wastewater is one of the wastewaters that has a color and is difficult to treat because it contains a large amount of non-degradable organic materials. The photo-assisted Fenton oxidation technique was applied to treat animal wastewater, and the optimal conditions of chemical oxygen demands (COD) removal were analyzed according to changes in pH, ferrous ion, H2O2, and ultraviolet (UV) light intensity as a single experimental condition. Experimental results showed that, under the single-factor experimental conditions, the optimal conditions for degradation of animal wastewater were pH 3.5, Fe(II) 0.01 M, H2O2 0.1 M, light intensity 3.524 mW/m2. Under the optimal conditions, COD removal efficiency was 91%, sludge production was 2.5 mL from 100 mL of solution, color removal efficiency was 80%, and coliform removal efficiency was 99.5%.

Components of Genetic Variation Associated with Second and Third Chromosome Gene Arrangements in Drosophila melanogaster

Genetics ◽  
1987 ◽  
Vol 116 (1) ◽  
pp. 87-97
Author(s):  
James A Ferrari
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Variation ◽  
Low Temperature ◽  
Interaction Effect ◽  
Quantitative Traits ◽  
Development Time ◽  
Gene Arrangement ◽  
Optimal Conditions ◽  
Experimental Conditions ◽  
Chromosome Gene

ABSTRACT The effects of naturally occuring combinations of second and third chromosome gene arrangements of Drosophila melanogaster on two quantitative traits were partitioned into parameters of additive, dominance and interaction components of genetic variation. Development time and preadult survival of the gene arrangement genotypes were measured under four experimental conditions. Gene arrangement effects, when significant, were predominantly additive under all conditions. Experimental conditions, however, did influence gene arrangement effects. A second chromosome effect on development time was detected when amount of food or temperature was reduced, but not under optimal conditions. A third chromosome additive effect on development was observed under all experimental conditions. A consistent interaction effect between second and third chromosome gene arrangements was detected only at low temperature. Gene arrangement effects on survival were not as consistent as for development time, but also depended on experimental conditions.

Improved D-Glucosamine Hydrochloride Preparation from Waste Hypha Residue of Citric Acid

2013 ◽  
Vol 864-867 ◽  
pp. 545-548
Author(s):  
Xiao Ling Sun ◽  
Zhi Tan ◽  
Ying Jiang ◽  
Min Yue Xu
Keyword(s):  
Acetic Acid ◽  
Statistical Analysis ◽  
Citric Acid ◽  
Acid System ◽  
Optimal Conditions ◽  
Orthogonal Array Design ◽  
Experimental Conditions ◽  
Array Design ◽  
Glucosamine Hydrochloride ◽  
Hcl Concentration

The improved preparation of D-glucosamine hydrochloride from waste hypha residue of citric acid was reported. The use of HCl and acetic acid system as an acid hydrolysis reagent led to a significant increase in the yield of D-Glucosamine hydrochloride (GluHCl). Other effects of various factors on the preparation of GluHCl were also investigated: temperature of acidification, HCl concentration, and reaction time. The experimental conditions were optimized by a L9 (34) orthogonal array design (OAD) with four factors at three levels using statistical analysis. Under optimal conditions, the yield of GluHCl reached 5.2%.

scholarly journals Optimization of Cellulase Enzyme Production by Co-cultures of Fungi Isolated from Lignocellulosic Waste

2020 ◽  
Vol 6 (5) ◽  
pp. 19-26
Author(s):  
Francis John V ◽  
Dr. Soloman P A
Keyword(s):  
Moisture Content ◽  
Incubation Time ◽  
Substrate Concentration ◽  
Enzyme Production ◽  
Trichoderma Viride ◽  
Cellulase Production ◽  
Optimal Conditions ◽  
Lignocellulosic Waste ◽  
Cellulase Enzyme ◽  
Degree Of Degradation

Fruit wastes were incubated with the mixture of cellulolytic fungi Penicillium citrinum, Aspergillus oryzae, and Trichoderma viride to hydrolyze the cellulosic components and to increase the degree of degradation. . The batch experiments are statistically designed and performed using Box-Benhken method of Response Surface Methodology to investigate the influence of major parameters viz., incubation time, temperature, pH, moisture content and substrate concentration on cellulase enzyme production. Maximum cellulase production of 2.03 Units/ml (U/ml) was detected by the RSM method in a mixed culture containing fungi at a ratio of 1: 1: 1 under optimal conditions at an incubation time of 5.27 days, a temperature of 34.09 °C, pH 4.85, moisture content of 63.83% and a substrate concentration of 5.03%.

scholarly journals Study of the Degradation of Trimethoprim Using Photo-Fenton Oxidation Technology

Water ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 207 ◽  
Author(s):  
Qi Wang ◽  
Wenjing Pang ◽  
Yingdan Mao ◽  
Quan Sun ◽  
Pengfei Zhang ◽  
...  
Keyword(s):  
High Performance ◽  
Degradation Rate ◽  
Fenton Oxidation ◽  
Design Experiment ◽  
H2o2 Concentration ◽  
Optimal Conditions ◽  
Single Factor ◽  
Experimental Conditions ◽  
Oxidation Technology ◽  
Central Composite

Trimethoprim is one of the representative drugs within the pharmaceutical and personal care products (PPCPs) group. The photo-Fenton oxidation technology was used to degrade trimethoprim in wastewater and the extent of degradation was analyzed by using high-performance liquid chromatography, then experimentally obtained the optimal conditions. Analysis of the experimental data showed that, under the single-factor experimental conditions, the optimal conditions for degradation were a pH of 4, an H2O2 concentration of 3.0 mmol/L, an FeSO4 concentration of 0.06 mmol/L, an initial trimethoprim concentration of 0.0689 mmol/L, and an ultraviolet (UV) intensity (UVA) of 12 mW/cm2. The interaction of pH and the concentration of H2O2 and Fe2+ have been further explored, it was obtained the following response surface results through the central composite design experiment: pH = 4.56, H2O2 concentration = 0.09 mmol/L, and Fe2+ concentration = 0.09 mmol/L. Under these conditions, it can be obtained a degradation rate of 99.95% after 6 min. There were similar results for three sets of parallel experiments, indicating that these simulation conditions were feasible.

Application of Response Surface Methodology for Improving the Yield of 1,5-bis(ptoluenesulfonyl)- 3,7-Dihydroxyoctahydro-1,5-Diazocine

2019 ◽  
Vol 16 (3) ◽  
pp. 398-404 ◽  
Author(s):  
Yang Zou ◽  
Jingyi Fei ◽  
Liangzhe Chen ◽  
Qingfeng Dong ◽  
Houbin Li
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Raw Materials ◽  
Low Cost ◽  
Product Yield ◽  
Synthesis Process ◽  
Optimal Conditions ◽  
Experimental Conditions ◽  
Simple Method ◽  
Ft Ir

Background: 3,3,7,7-tetrakis (difluoramino) octahydro-1,5-dinitro-1,5-diazocine (HNFX), as an important oxidizer in propellants, has received much attention due to its high density and energy. However, there are many difficulties that need to be solved, such as complex synthetic processes, low product yield, high cost of raw materials and complicated purification. In the synthesis of HNFX, the intermediate named 1,5-bis (p-toluenesulfonyl)-3,7-dihydroxyoctahydro-1, 5-diazocine (gem-diol), is difficult to synthesize. Methods: A simple method was used to synthesize the gem-diol. This prepared gem-diol was characterized by FT-IR, 1H NMR, melting point and mass spectrometry. In order to increase the yield of gem-diol, response surface methodology (RSM) was introduced to optimize experimental conditions. Results: After the establishment of the model, the optimal conditions of synthesis were found to be 9.33h for reaction time, 6.13wt. % for the concentration of NaOH and 1.38:1 for ratio of ECH (p-toluenesulfonamide): TCA (epichlorohydrin). Under the optimal conditions, the experimental value and the predicted value of yield were 22.18% and 22.92%, respectively. Conclusion: 1,5-bis (p-toluenesulfonyl)-3,7-dihydroxyoctahydro-1,5-diazocine (gem-diol) can be synthesized using the low cost of chemical materials, including p-toluenesulfonamide, epichlorohydrin, sodium hydroxide and ethanol. Response surface methodology (RSM) is an effective method to optimize the synthesis process, thereby improving the yield of gem-diol.

Preparation and Characterization of Formaldehyde Crosslinked Chitosan

2011 ◽  
Vol 239-242 ◽  
pp. 279-282 ◽  
Author(s):  
Juan Qin Xue ◽  
Jing Xian Li ◽  
Ming Wu ◽  
Wei Wang ◽  
Dong Ni Ma
Keyword(s):  
Reaction Time ◽  
Raw Materials ◽  
Cross Linking ◽  
Crosslinking Reaction ◽  
Optimal Conditions ◽  
Experimental Conditions ◽  
Crosslinked Chitosan ◽  
Chitosan Resin ◽  
Morphology Changes

Using formaldehyde as a crosslinking reagena novel cross-linked chitosan resin was synthesized by orthogonal. The resin material with good properties of sphericity and acidresistivity can be prepared under the optimal experimental conditions, which are found to be 1:6 for the ratio of chitosan and formaldehyde, 60°C for the temperature, 1 h for the reaction time, 640r/min for the stirring rate and 9 for the pH, and the cross-linking rate under the optimal conditions is 401.86%. SEM shows the surface morphology changes of raw materials and products; IR of the raw materials and products shows that the reaction occurs mainly on the amino and the hydroxyl of chitosan, and TG shows that the crosslinking reaction of chitosan can change its heat resistance.

scholarly journals Investigating the effects of substrate morphology and experimental conditions on the enzymatic hydrolysis of lignocellulosic biomass through modeling

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Jessica C. Rohrbach ◽  
Jeremy S. Luterbacher
Keyword(s):  
Mass Transfer ◽  
Lignocellulosic Biomass ◽  
Concentration Gradient ◽  
Internal Mass ◽  
Enzyme Loading ◽  
Experimental Conditions ◽  
Biomass Deconstruction ◽  
Internal Mass Transfer ◽  
Cellulose Surface

Abstract Background Understanding how the digestibility of lignocellulosic biomass is affected by its morphology is essential to design efficient processes for biomass deconstruction. In this study, we used a model based on a set of partial differential equations describing the evolution of the substrate morphology to investigate the interplay between experimental conditions and the physical characteristics of biomass particles as the reaction proceeds. Our model carefully considers the overall quantity of cellulase present in the hydrolysis mixture and explores its interplay with the available accessible cellulose surface. Results Exploring the effect of various experimental and structural parameters highlighted the significant role of internal mass transfer as the substrate size increases and/or the enzyme loading decreases. In such cases, diffusion of cellulases to the available cellulose surface limits the rate of glucose release. We notably see that increasing biomass loading, while keeping enzyme loading constant should be favored for both small- (R < 300 $$\mu m$$ μ m ) and middle-ranged (300 < R < 1000 $$\mu m$$ μ m ) substrates to enhance enzyme diffusion while minimizing the use of enzymes. In such cases, working at enzyme loadings exceeding the full coverage of the cellulose surface (i.e. eI>1) does not bring a significant benefit. For larger particles (R > 1000 $$\mu m$$ μ m ), increases in biomass loading do not offset the significant internal mass transfer limitations, but high enzyme loadings improve enzyme penetration by maintaining a high concentration gradient within the particle. We also confirm the well-known importance of cellulose accessibility, which increases with pretreatment. Conclusions Based on the developed model, we are able to propose several design criteria for deconstruction process. Importantly, we highlight the crucial role of adjusting the enzyme and biomass loading to the wood particle size and accessible cellulose surface to maintain a strong concentration gradient, while avoiding unnecessary excess in cellulase loading. Theory-based approaches that explicitly consider the entire lignocellulose particle structure can be used to clearly identify the relative importance of bottlenecks during the biomass deconstruction process, and serve as a framework to build on more detailed cellulase mechanisms.

Study on TCF Bleaching of Reed Displacement Cooking Pulp

2013 ◽  
Vol 726-731 ◽  
pp. 543-547
Author(s):  
Ting Ting Fan ◽  
Ying Han ◽  
Guang Wei Sun ◽  
Jing Hui Zhou
Keyword(s):  
Hydrogen Peroxide ◽  
Peracetic Acid ◽  
Optimal Conditions ◽  
Experimental Conditions ◽  
Environment Friendly ◽  
Bleaching Process ◽  
Paper Making ◽  
Bleached Pulp ◽  
Method Yield ◽  
Temperature Time

With the improvement of environmental protection requirements, paper-making enterprises are imperative to eliminate pollution directly in production. This paper aims to adopt environment-friendly bleaching method, yield good quality pulp products. Op-Pa-P bleaching process of reed displacement cooking pulp is studied in this paper (O-oxygen, P-hydrogen peroxide, Pa-peracetic acid ). The experimental conditions of Op and Pa stage were optimized respectively. It included oxygen pressure, temperature, time in Op stage and charge of peracetic acid, temperature, time in Pa stage. The results show that the optimal technological conditions of Op are: 0.9Mpa, 100°C, 70min, Op stage can make brightness increase by 57.3%, viscosity decrease by 25% and KMnO4 number reduce to 2.6. Pa stage optimal conditions are Pa charge 1.5%, 70°C, 75min, brightness reached to 79.1 %ISO, KMnO4 number to 1.0, viscosity to 631mL.g-1. The brightness of P bleached pulp reached to 84.8%ISO, viscosity 601 mL.g-1, KMnO4 number 0.8.

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