scholarly journals Research on Catalytic Denitrification by Zero-Valent Iron (Fe0) and Pd-Ag Catalyst

2021 ◽  
Author(s):  
Yu Zhou ◽  
Yupan Yun ◽  
Xueyou Wen
Keyword(s):  
Response Surface Methodology ◽  
Catalytic Performance ◽  
Zero Valent Iron ◽  
Optimal Conditions ◽  
Single Factor ◽  
Condition Optimization ◽  
Performance Response ◽  
Real Wastewater ◽  
Ag Catalyst ◽  
Orthogonal Tests

Abstract This study primarily focused on how to effectively remove nitrate by catalytic denitrification through zero-valent iron (Fe0) and Pd-Ag catalyst. In order to get better catalytic performance, response surface methodology (RSM), instead of the single factor experiments and orthogonal tests, was firstly applied to optimize the condition parameters of the catalytic process. Results indicated that RSM is accurate and feasible for the condition optimization of catalytic denitrification. Better catalytic performance (71.6% N2 Selectivity) was obtained under the following conditions: 5.1 pH, 127 min reaction time, 3.2 mass ration (Pd: Ag), and 4.2 g/L Fe0, which was higher than the previous study designed by the single factor experiments (68.1%) and orthogonal tests (68.7%). However, under the optimal conditions, N2 selectivity showed a mild decrease (69.3%), when the real wastewater was used as the influent. Further study revealed that the cations (e.g., K+, Na+, Ca2+, Mg2+, and Al3+) and anions (e.g., Cl-, HCO3-, and SO42-) exist in wastewater may have distinctive influence on N2 selectivity. Finally, the reaction mechanism and kinetic model of catalytic denitrification were further studied.

scholarly journals OPTIMIZATION OF EXTRACTION PARAMETERS FOR TOTAL FLAVONOIDS FROM GARDENIA GUMMIFERA GUM RESIN BY RESPONSE SURFACE METHODOLOGY

2016 ◽  
Vol 8 (11) ◽  
pp. 64 ◽  
Author(s):  
Snehal B. Bhandare ◽  
Kirti S. Laddha
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Close Agreement ◽  
Extraction Time ◽  
Total Flavonoids ◽  
Extraction Temperature ◽  
Optimal Conditions ◽  
Single Factor ◽  
Solvent Concentration ◽  
Extraction Parameters

Objective: To optimize the extraction parameters for determining the highest yield of Total Flavonoids from Gardenia gummifera gum resin.Methods: In the present study, response surface methodology (RSM) with three level Box Behenken design (BBD) was performed to optimize extraction parameters for total flavonoids. Solvent concentration(A), extraction time (B) and extraction temperature(C) were considered for single factor experiment.Results: The highest flavonoid concentration was obtained with acetone 45.00% v/v, time 101.46 min, temperature 41.57 °C. The average experimental TFC under optimal conditions was 161.14 mg/g which was in close agreement with the predicted value of 163.42 mg/g.Conclusion: RSM-BBD is successfully applied in optimizing extraction conditions for extraction of total flavonoids from G. gummifera gum resin.

Optimization of the Preparation Technology of Resistant Starch of Cowpea Using Response Surface Methodology

2012 ◽  
Vol 554-556 ◽  
pp. 909-917 ◽  
Author(s):  
Wei Wen Huang ◽  
Wei Wang ◽  
Ji Lie Li ◽  
Zhong Hai Li
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Resistant Starch ◽  
Preparation Process ◽  
Optimal Conditions ◽  
Single Factor ◽  
Preparation Technology ◽  
Starch Concentration ◽  
Main Factors ◽  
Optimized Conditions

Response surface methodology was used to optimize the preparation technology of resistant starch (RS) production by raw cowpea bean starch. In the first optimization step, single factor experiments designed was used to evaluate the influence of RS yield. The RS yield were influenced significantly by some factors of preparation RS, including the starch concentration, autoclaving time, pullulanase dosage and enzymolysis temperature. The others in the investigation scope had no significant influence on the RS production. In the last step, four main factors were further optimized using Box-Behnken designs and response surface analysis. The optimized conditions in the process of preparation RS were starch concentration as 29%, autoclaving time as 38min, pullulanase dosage as 4.0PUN/g, enzymolysis temperature as 60°C. In our optimal conditions, rather good RS yield was 23.52±0.15% and repeatability of the preparation process was good which was valuable in further production.

Degradation of nicosulfuron by a novel isolated bacterial strain Klebsiella sp. Y1: condition optimization, kinetics and degradation pathway

2016 ◽  
Vol 73 (12) ◽  
pp. 2896-2903 ◽  
Author(s):  
Lin Wang ◽  
Xiaolin Zhang ◽  
Yongmei Li
Keyword(s):  
Response Surface Methodology ◽  
Bacterial Strain ◽  
Degradation Pathway ◽  
Optimal Conditions ◽  
16S Rdna Sequence ◽  
16S Rdna Sequence Analysis ◽  
Condition Optimization ◽  
Metabolic Degradation ◽  
Hydrolysis Of ◽  
Optimal Ph

Abstract A novel bacterial strain Klebsiella sp. Y1 was isolated from the soil of a constructed wetland, and it was identified based on the 16S rDNA sequence analysis. The co-metabolic degradation of nicosulfuron with glucose by Klebsiella sp. Y1 was investigated. The response surface methodology analysis indicated that the optimal pH and temperature were 7.0 and 35 °C, respectively, for the degradation of nicosulfuron. Under the optimal conditions, the degradation of nicosulfuron fitted Haldane kinetics model well. The removal of nicosulfuron was triggered by the acidification of glucose, which accelerated the hydrolysis of nicosulfuron. Then, the C–N bond of the sulfonylurea bridge was attacked and cleaved. Finally, the detected intermediate 2-amino-4,6-dimethoxypyrimidine was further biodegraded.

scholarly journals Homogenate Extraction of Crocins from Saffron Optimized by Response Surface Methodology

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Yingpeng Tong ◽  
Yu Jiang ◽  
Dan Guo ◽  
Yongqiu Yan ◽  
Shiping Jiang ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Ethanol Concentration ◽  
Extraction Yield ◽  
Extraction Time ◽  
Process Conditions ◽  
Extraction Temperature ◽  
Single Factor ◽  
Extraction Voltage ◽  
Homogenate Extraction

Saffron, which has many kinds of biological activities, has been widely used in medicine, cosmetics, food, and other fields of health promotion industries. Crocins are the main component of saffron (Crocus sativus L.). At present, most of the extraction methods for crocins require long time or special instruments to complete the process and some of them are not suitable for industrial production at present. In this article, homogenate extraction technology which is a convenient and efficient method was developed for crocins extraction from saffron. Firstly, the influences of extraction voltage, extraction time, ethanol concentration, and temperature on crocins yield were studied by single factor experiments; and then response surface methodology (RSM) was used to optimize levels of four variables based on the result of single factor experiments. Results showed that the optimum extraction process conditions for crocins were as follows: extraction voltage, 110 V; ethanol concentration, 70%; extraction temperature, 57°C; and extraction time, 40 s. Based on these conditions, the extraction yield of crocins can reach 22.76% which is higher than ultrasonic extraction method. Therefore, homogenate extraction is an effective way to extract crocins from saffron with higher extraction yield and shorter extraction time.

Optimization of the Ultrasonic Extraction of Gypenoside III from Gynostemma pentaphyllum by Response Surface Methodology

2012 ◽  
Vol 550-553 ◽  
pp. 1866-1870
Author(s):  
Xiao Dan Tang ◽  
Hai Yang Hang ◽  
Shao Yan Wang ◽  
Jing Xiang Cong
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Extraction Yield ◽  
Raw Material ◽  
Extraction Temperature ◽  
Optimal Conditions ◽  
Gynostemma Pentaphyllum ◽  
Bioactive Component ◽  
Yield Value ◽  
Ultrasonic Time

Gypenosides III is a major bioactive component which is rich in Gynostemma pentaphyllum. For better utilization of the native resource, response surface methodology was used to optimize the extraction conditions of gypenosides III from G. pentaphyllum. The effects of three independent variables on the extraction yield of gypenosides III were investigated and the optimal conditions were evaluated by means of Box-Behnken design. The optimal conditions are as follows: ratio of ethanol to raw material 25, extraction temperature 58°C and ultrasonic time 25min. Under these conditions, the yield of gypenoside III is 1.216±0.05%, which is agreed closely with the predicted yield value.

Removal of phenol from steel wastewater by combined electrocoagulation with photo-Fenton

2018 ◽  
Vol 78 (6) ◽  
pp. 1260-1267 ◽  
Author(s):  
Mohammad Malakootian ◽  
Mohammad Reza Heidari
Keyword(s):  
Reaction Time ◽  
Removal Efficiency ◽  
Current Density ◽  
Steel Industry ◽  
High Efficiency ◽  
Oxygen Demand ◽  
Optimal Conditions ◽  
Suitable Alternative ◽  
Steel Mills ◽  
Real Wastewater

Abstract Phenol and its derivatives are available in various industries such as refineries, coking plants, steel mills, drugs, pesticides, paints, plastics, explosives and herbicides industries. This substance is carcinogenic and highly toxic to humans. The purpose of the study was to investigate the removal of phenol from wastewater of the steel industry using the electrocoagulation–photo-Fenton (EC-PF) process. Phenol and chemical oxygen demand (COD) removal efficiency were investigated using the parameters pH, Fe2+/H2O2, reaction time and current density. The highest removal efficiency rates of phenol and COD were 100 and 98%, respectively, for real wastewater under optimal conditions of pH = 4, current density = 1.5 mA/cm2, Fe2+/H2O2 = 1.5 and reaction time of 25 min. Combination of the two effective methods for the removal of phenol and COD, photocatalytic electrocoagulation photo-Fenton process is a suitable alternative for the removal of organic pollutants in industry wastewater because of the low consumption of chemicals, absence of sludge and other side products, and its high efficiency.

scholarly journals Response surface methodology-artificial neural network based optimization and strain improvement of cellulase production by Streptomyces sp.

2020 ◽  
Vol 36 (4) ◽  
Author(s):  
Ega Soujanya Lakshmi ◽  
Manda Rama Narasinga Rao ◽  
Muddada Sudhamani
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Response Surface Methodology ◽  
Response Surface ◽  
Wild Strain ◽  
Cellulase Activity ◽  
Cellulase Production ◽  
Optimal Conditions ◽  
Zone Formation ◽  
Artificial Neural

ABSTRACT Thirty seven different colonies were isolated from decomposing logs of textile industries. From among these, a thermotolerant, grampositive, filamentous soil bacteria Streptomyces durhamensis vs15 was selected and screened for cellulase production. The strain showed clear zone formation on CMC agar plate after Gram’s iodine staining.  Streptomyces durhamensis vs15 was further confirmed for cellulase production by estimating the reducing sugars through dinitrosalicylic acid (DNS) method. The activity was enhanced by sequential mutagenesis using three mutagens of ultraviolet irradiation (UV), N methyl-N’-nitro-N-nitrosoguanidine (NTG) and Ethyl methane sulphonate (EMS). After mutagenesis, the cellulase activity of GC23 (mutant) was improved to 1.86 fold compared to the wild strain (vs15). Optimal conditions for the production of cellulase by the GC 23 strain were evaluated using Response Surface Methodology (RSM) and Artificial Neural Network (ANN). Effect of pH, temperature, duration of incubation, , and substrate concentration on cellulase production were evaluated. Optimal conditions for the production of cellulase enzyme using Carboxy Methyl Cellulase as a substrate are 55 oC of temperature, pH of 5.0 and incubation for 40 h. The cellulase activity of the mutant Streptomyces durhamensis GC23 was further optimised to 2 fold of the activity of the wild type by RSM and ANN.  

scholarly journals Applying Response Surface Methodology to optimize the decarbonization process of Timahdit oil shale

2019 ◽  
Vol 8 (5) ◽  
pp. 372-379 ◽  
Author(s):  
Laila Makouki ◽  
Meriem Tarbaoui ◽  
Samia Glissi ◽  
Said Mansouri ◽  
Hassan Hannache ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Acetic Acid ◽  
Response Surface ◽  
Oil Shale ◽  
Processing Time ◽  
Texture Evolution ◽  
Optimal Conditions ◽  
X Ray ◽  
Decarbonization Process ◽  
Scanning Electron

The present article aims to optimize the decarbonization of Timahdit oil shale layer Y by removing carbonates from the raw rock using acetic acid. The response surface methodology “central composite design (CCD)” has been used as a method of optimization to study the 3 factors of the process. The factors studied are the concentration of the acid, the processing time, and the ratio (liquid/solid). The optimal conditions with 68.17% of residue rate are obtained with 2 mol/l as concentration, 120 min as a time of treatment and 10.02 for the ratio.The raw (Y) and optimized materials (YO) were characterized by Scanning Electron Microscopy (SEM), X-ray fluorescence (XRF) and X-ray diffraction (XRD). The results showed that the acetic acid used to remove carbonates affects the chemical composition and the texture evolution of the residues.

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