scholarly journals Degradation of Oxytetracycline by Electrochemical, Fenton and Electro-fenton Processes Using SS316 and SS316/β-PbO2 Anodes: Process Optimization Using Rsm-ccd, Bioassay Test and Degradation Pathway

2021 ◽  
Author(s):  
Kamal Hasani ◽  
Sama Hosseini ◽  
Heliya Gholizadeh ◽  
Abdollah Dargahi ◽  
Mehdi Vosoughi
Keyword(s):  
Degradation Pathway ◽  
Electrochemical Process ◽  
Fenton Process ◽  
Optimal Conditions ◽  
Optimal Value ◽  
Anode Electrode ◽  
Optimal Values ◽  
Electrochemical Fenton ◽  
And Staphylococcus Aureus ◽  
Central Composite

Abstract The aim of the present study was to evaluate the efficiency of advanced oxidation processes (electrochemical, Fenton and electro-Fenton) in the removal of oxytetracycline using SS316 and SS316/β-PbO2 anodes. This study was performed experimentally on a laboratory scale in a 250 mL reactor. First, experiments were designed for the electrochemical process using a central composite design, and the optimal conditions for the variables pH(3.53), electric current density(3.85mA/cm2), initial concentration of oxytetracycline (20mg/L) and electrolysis time (42.35min) was obtained; then, under these conditions, the efficiency of Fenton process with FeSO4 variable without the presence of electrodes was evaluated, and its optimal value was 0.3 g/L, and then in the presence of optimal values ​​of the above 5 variables, the efficiency of electro-Fenton process with H2O2 changes were investigated and the optimal value of 0.12 was obtained for H2O2. The removal efficiencies of oxytetracycline in electrochemical, Fenton, and electro-Fenton processes were 84.7%, 73.4%, and 98.2%, respectively. Under optimal conditions, the SS316/β-PbO2 anode electrode enhanced the oxytetracycline efficiency by electron-Fenton process to 100%. The results of bioassay with microorganisms showed that the reduction of toxicity of the effluent treated by electro-Fenton process for Pseudomonas aeruginosa and Staphylococcus aureus was 84.5% and 69%, respectively.

scholarly journals OPTIMIZING THE PROCESS OF TRANSFORMING COFFEE HUSKS INTO BIOCHAR BY MEANS OF HYDROTHERMAL CARBONIZATION

2018 ◽  
Vol 54 (4B) ◽  
pp. 138
Author(s):  
Tran Thi Hien
Keyword(s):  
Maximum Yield ◽  
Hydrothermal Carbonization ◽  
Optimal Conditions ◽  
Coffee Husk ◽  
Optimal Value ◽  
Face Centered ◽  
Composite Face ◽  
Temperature Time ◽  
Central Composite ◽  
Water Ratio

The conditions of the hydrothermal carbonization process to produce biochar from coffee husk will be optimized for maximum yield. Besides, response surface methodology (RSM) and central composite face-centered (CCF) method will be used in designing experiments. Also, the optimal value of factors such as temperature, time and biomass: water ratio which can provide a maximum yield of biochar will be worked out using Modde 5.0. As a result, the optimal conditions for maximum yield of biochar was obtained as temperature of 180 oC, 3.5 h and biomass: water ratio of 15 %. It can also be concluded that temperature has greater impact on the transformation of biochar than time and biomass: water ratio.

Computational simulation applied to improve fuel bioethanol distillation

2013 ◽  
pp. 645-650
Author(s):  
Fabio R.M. Batista ◽  
Antonio J.A. Meirelles
Keyword(s):  
Experimental Validation ◽  
Computational Simulation ◽  
Industrial Plant ◽  
Careful Study ◽  
Optimal Conditions ◽  
Liquid Equilibrium ◽  
Steam Consumption ◽  
Wine Composition ◽  
Standard Solution ◽  
Central Composite

Experimental validation of the process simulation a typical industrial bioethanol unit was conducted, comparing the obtained results with the information collected in an industrial plant. A standard solution containing water, ethanol and 17 congeners was chosen to represent the fermented must, whose composition was selected according to analyses of samples of industrial wines. A careful study of the vapour-liquid equilibrium of the wine components was performed. An attempt to optimise the industrial plant was conducted considering two optimising approaches: the central composite design (CCD) and the Sequential Quadratic Programming (SQP). The process was investigated in terms of bioethanol alcoholic graduation, ethanol recovery, energy consumption and ethanol loss. The results showed that the simulation approach was capable of correctly reproducing a real plant of bioethanol distillation and that the optimal conditions are slightly different from those used at the industrial plant investigated. Substantial fluctuations in wine composition were easily controlled for the two loop controls preventing an off-specification product. The optimised conditions indicate a distillation process able to produce bioethanol according to the legislation requirements and with appropriate steam consumption and loss of ethanol. However, for the production of alcohols with superior qualities, substantial changes in the production system may be required.

scholarly journals Photocatalytic-Fenton Process under Simulated Solar Radiation Promoted by a Suitable Catalyst Selection

Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 885
Author(s):  
Aida M. Díez ◽  
Helen E. Valencia ◽  
Maria Meledina ◽  
Joachim Mayer ◽  
Yury V. Kolen'ko
Keyword(s):  
Methylene Blue ◽  
Solar Radiation ◽  
Water Scarcity ◽  
Published Data ◽  
Fenton Process ◽  
Optimal Conditions ◽  
Operational Conditions ◽  
The Future ◽  
Simulated Solar Radiation ◽  
Catalyst Selection

Considering water scarcity, photo-based processes have been presented as a depollution technique, which should be optimized in order to be applied in the future. For that, the addition of an active photocatalyst and the usage of solar radiation are mandatory steps. Thus, Fe3O4–SiO2–TiO2 was synthesized, and its performance was evaluated using simulated solar radiation and methylene blue as a model pollutant. Under optimal conditions, 86% degradation was attained in 1 h. These results were compared to recent published data, and the better performance can be attributed to both the operational conditions selection and the higher photocatalyst activity. Indeed, Fe3O4–SiO2–TiO2 was physico-chemically characterized with techniques such as XRD, N2 isotherms, spectrophotometry, FTIR, electrochemical assays and TEM.

scholarly journals Sulfaquinoxaline Oxidation and Toxicity Reduction by Photo-Fenton Process

2021 ◽  
Vol 18 (3) ◽  
pp. 1005
Author(s):  
Vanessa Ribeiro Urbano ◽  
Milena Guedes Maniero ◽  
José Roberto Guimarães ◽  
Luis J. del Valle ◽  
Montserrat Pérez-Moya
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pilot Plant ◽  
Environmental Water ◽  
Fenton Process ◽  
Experimental Conditions ◽  
Laboratory Bench ◽  
Degradation Rates ◽  
Bacterial Growth Inhibition ◽  
And Staphylococcus Aureus

Sulfaquinoxaline (SQX) has been detected in environmental water samples, where its side effects are still unknown. To the best of our knowledge, its oxidation by Fenton and photo-Fenton processes has not been previously reported. In this study, SQX oxidation, mineralization, and toxicity (Escherichia coli and Staphylococcus aureus bacteria) were evaluated at two different setups: laboratory bench (2 L) and pilot plant (15 L). The experimental design was used to assess the influence of the presence or absence of radiation source, as well as different H2O2 concentrations (94.1 to 261.9 mg L−1). The experimental conditions of both setups were: SQX = 25 mg L−1, Fe(II) = 10 mg L−1, pH 2.8 ± 0.1. Fenton and photo-Fenton were suitable for SQX oxidation and experiments resulted in higher SQX mineralization than reported in the literature. For both setups, the best process was the photo-Fenton (178.0 mg L−1 H2O2), for which over 90% of SQX was removed, over 50% mineralization, and bacterial growth inhibition less than 13%. In both set-ups, the presence or absence of radiation was equally important for sulfaquinoxaline oxidation; however, the degradation rates at the pilot plant were between two to four times higher than the obtained at the laboratory bench.

Degradation of Amaranth azo dye in water by heterogeneous photo-Fenton process using FeWO4 catalyst prepared by microwave irradiation

2015 ◽  
Vol 73 (1) ◽  
pp. 88-94 ◽  
Author(s):  
Eric da Cruz Severo ◽  
Chayene Gonçalves Anchieta ◽  
Vitória Segabinazzi Foletto ◽  
Raquel Cristine Kuhn ◽  
Gabriela Carvalho Collazzo ◽  
...  
Keyword(s):  
Azo Dye ◽  
Fenton Reaction ◽  
Catalytic Properties ◽  
Interactive Effects ◽  
Fenton Process ◽  
Operational Parameters ◽  
Treatment Efficiency ◽  
Experimental Conditions ◽  
Decolorization Efficiency ◽  
Central Composite

FeWO4 particles were synthesized by a simple, rapid and facile microwave technique and their catalytic properties in heterogeneous photo-Fenton reaction were evaluated. This material was employed in the degradation of Amaranth azo dye. Individual and interactive effects of operational parameters such as pH, dye concentration and H2O2 dosage on the decolorization efficiency of Amaranth dye were evaluated by 23 central composite design. According to characterization techniques, a porous material and a well-crystallized phase of FeWO4 oxide were obtained. Regarding the photo-Fenton reaction assays, up to 97% color and 58% organic carbon removal were achieved in the best experimental conditions. In addition, the photo-Fenton process maintained treatment efficiency over five catalyst reuse cycles to indicate the durability of the FeWO4 catalyst. In summary, the results reveal that the synthesized FeWO4 material is a promising catalyst for wastewater treatment by heterogeneous photo-Fenton process.

Modeling of supercritical fluid extraction of flavonoids from Calycopteris floribunda leaves

2014 ◽  
Vol 68 (3) ◽  
Author(s):  
Xiong Liu ◽  
Dong-Liang Yang ◽  
Jia-Jia Liu ◽  
Kuan Xu ◽  
Guo-Hui Wu
Keyword(s):  
Supercritical Fluid Extraction ◽  
Supercritical Fluid ◽  
Extraction Process ◽  
Optimal Conditions ◽  
Fluid Extraction ◽  
Pressure Method ◽  
Organic Solvent Extraction ◽  
Drug Lead ◽  
Temperature And Pressure ◽  
Central Composite

AbstractThe aim of this study was to obtain flavonoids extracts from Calycopteris floribunda leaves using supercritical fluid extraction (SFE) with CO2 and a co-solvent. Pachypodol, a potential anticancer drug lead compound separated from the extracts, was examined. Classical organic solvent extraction (CE) with ethanol was performed to evaluate the high pressure method. HPLC analysis was introduced to interpret the differences between SFE and CE extracts in terms of antioxidant activity and the concentration of pachypodol. SFE kinetics and mathematical modeling of the overall extraction curves (OEC) were investigated. Evaluation of the models against experimental data showed that the Sovová model performs the best. The supercritical fluid extraction process was optimized using a central composite design (CCD), where temperature and pressure were adjusted. The optimal conditions of SFE were: pressure of 30 MPa and temperature of 35°C.

scholarly journals Optimisation of Biogas Production through Variation of PH, Detention Time and Ratio of Substrate to Water for Rural Utilization

2019 ◽  
Vol 2 (1) ◽  
pp. 52-59 ◽  
Author(s):  
A G Jiya ◽  
U J Ijah ◽  
M Galadima ◽  
U G Akpan
Keyword(s):  
Rural Community ◽  
Numerical Optimization ◽  
Biogas Production ◽  
High Yield ◽  
Input Process ◽  
Domestic Waste ◽  
Detention Time ◽  
Biogas Yield ◽  
Optimal Values ◽  
Central Composite

A response surface methodology (RSM) was utilized in this study for optimisation of biogas production process. The optimal values of process parameter capable of giving a high yield of biogas were established. A biodigester of 20 liters capacity capable of producing biogas from rural household domestic waste was designed, constructed and used in the study. Its major units are the anaerobic and gas collecting units. The process parameters investigated are the pH of the substrate, detention time and ratio of substrate to water while the yield of biogas was used as performance characteristics. The experiment was based on a central composite rotatable design (CCRD). The results revealed that the highest yield of biogas was obtained from a combination of detention time of 30 days, ratio of substrate to water of 1:1 and pH of 7, while the least yield of biogas of 11 cm3 was obtained from combination of detention time of 30 days, ratio of substrate to water of 1:3 and pH of 2. Numerical optimization carried out with the goal of maximizing the biogas yield revealed optimum values of detention time of 40 days, the ratio of substrate and water used; 1:2 and pH of 6.71 for biogas of 771.77 cm3 with the desirability of 0.9850. The detention time had the highest significant effects on the yield of biogas. The results of this study provided standard input process variables capable of yielding the optimum yield of biogas for the rural community.

PRODUCTIVE LONGEVITY OF COWS: INFLUENCE OF METABOLITES OF METABOLISM ON REPRODUCTIVE FUNCTION

2020 ◽  
pp. 19-22
Author(s):  
Е.О. КРУПИН ◽  
Ш.К. ШАКИРОВ
Keyword(s):  
Life Expectancy ◽  
Ketone Bodies ◽  
Reproductive Function ◽  
Lactation Period ◽  
Protein Ratio ◽  
Protein Mass ◽  
Service Period ◽  
Optimal Value ◽  
Mass Fractions ◽  
Optimal Values

Дана оценка причин выбраковки дойных коров из стад, определена продолжительность их жизни, установлены соотношения МДЖ и МДБ в молоке коров и на основании этого выявлены взаимосвязи с содержанием кетоновых тел в молоке и некоторыми показателями воспроизводства. Наиболее часто животные выбывают из стада в связи с гинекологическими заболеваниями — 45,9%, за первые 100 дней лактации — 42,05%. Продолжительность жизни коров, выбракованных вследствие инфекционных и инвазионных болезней, является минимальной и составляет 4 года, у коров, выбывших по причине внутренних незаразных и хирургических болезней, на 15 и 20% больше. При соотношении массовых долей жира и белка (СЖБ) 1,10 и менее содержание бета-гидроксимасляной кислоты (БОМК) в молоке достоверно (на 80%, P<0,01) превышает данный показатель у животных с оптимальными значениями СЖБ. У коров с оптимальным СЖБ уровень ацетона в молоке был выше порогового на 28,57%, а у животных с низкими значениями СЖБ достоверное превышение составило 42,85% (P<0,05). Особи с СЖБ ниже оптимальных значений в первые 100 дней характеризовались более длительным периодом лактации в целом на 8,57%, в то время как у животных с оптимальным СЖБ ее продолжительность приближалась к стандартной и составила 308,13 дня (P<0,001), межотельный период был на 5,39% менее продолжительным (P<0,001). При оптимальных значениях СЖБ длительность сервис-периода равнялась 112,91 дня, что на 14,73% короче (P<0,001) продолжительности сервис-периода у животных с низкими значениями СЖБ. The analysis of the reasons for leaving dairy cows from the herd was carried out. The life expectancy of cows has been determined. The ratios of fat to protein mass fractions in cow's milk have been established. The relationship between the content of ketone bodies in milk and reproductive indicators in animals was revealed. Most often, animals leave the herd due to gynecological diseases (45.9%), and in the first 100 days of lactation (42.05%). The life expectancy of cows culled due to infectious and invasive diseases is minimal and amounts to 4 years. For cows abandoned due to internal non-communicable and surgical diseases, life expectancy was 15 and 20% longer. When the ratio of mass fractions of fat to protein was 1.10 or less, the content of beta-hydroxybutyric acid in milk significantly (by 80%, P<0.01) exceeded this indicator in animals with optimal values of the ratio of fat to protein. In cows with an optimal fat to protein ratio, the acetone level in milk was 28.57% above normal. In animals with a low value of the ratio of fat to protein, the significant excess was 42.85% (P<0.05). Animals with a ratio of fat to protein below the optimal value were characterized by a longer lactation period in general by 8.57%. In animals with an optimal fat-to-protein ratio, the duration of lactation approached the standard one and was 308.13 days (P<0.001), and the interbody period was 5.39% shorter (P<0.001). With optimal values of the fat-to-protein ratio, the duration of the service period was 112.91 days, which is 14.73% shorter (P<0.001) than the duration of the service period in animals with low values of the fat-to-protein ratio.

Bondonic Electrochemistry

2017 ◽  
pp. 277-359
Author(s):  
Mihai V. Putz ◽  
Marina A. Tudoran ◽  
Marius C. Mirica
Keyword(s):  
Photovoltaic Effect ◽  
Cost Effective ◽  
Electrochemical Process ◽  
Electronic Charge ◽  
Galvanic Cells ◽  
Chemistry Modeling ◽  
Anode Electrode ◽  
Electronic Charge Transfer ◽  
Photo Current

The main concepts of electrochemistry are reviewed in a fundamental manner as well for the applicative approach of asymmetric currents in the galvanic cells; the whole electrochemical process is eventually combined with embedded the bondonic chemistry modeling the electronic charge transfer sensitizing the anode electrode and the overall photovoltaic effect through the electrolyte fulfilling the red-ox closed circuit; the resulted bondonic electrochemistry may be suited for integration with the fresh approach of sensitization of the solar cells by the bonding quantum dots (the bondots), see the preceding chapter of the same book, towards a bondonic-bondotic photo-electrochemical integrated and cost-effective photo-current conversion; it may be used as well as for laser-based technique in controlling the electrochemical effects with optical lattices acting towards condensing the electrons into bondons and controlling them thereof.

scholarly journals Pineapple Bark Performance in Dyes Adsorption: Optimization by the Central Composite Design

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Ahlam Fegousse ◽  
Abdelali El Gaidoumi ◽  
Youssef Miyah ◽  
Rabea El Mountassir ◽  
Anissa Lahrichi
Keyword(s):  
Central Composite Design ◽  
Design Methodology ◽  
Brilliant Green ◽  
Optimal Conditions ◽  
Initial Concentration ◽  
Dyes Adsorption ◽  
Experimental Design Methodology ◽  
Central Composite ◽  
Adsorbent Dose ◽  
Scanning Electron

This work is concerned with the study of the adsorption in aqueous medium of a three-dye mixture which contains Methylene Blue, Brilliant Green, and Congo Red on the pineapple bark. This adsorbent material has been characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The experimental design methodology, based on the response surface methodology (RSM) by the central composite design (CCD), has been applied for the optimization of the parameters, namely, the temperature, dose of the adsorbent, and pH. The yield reached 98.91% under optimal conditions (T = 30°C; adsorbent dose = 2.5 g·L−1; pH = 9.8) at an initial concentration of 20 mg·L−1.

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