scholarly journals Kinetics and Optimization by Response Surface Methodology of Aerobic Bioremediation. Geoelectrical Parameter Monitoring

2020 ◽  
Vol 10 (1) ◽  
pp. 405 ◽  
Author(s):  
Carla Maria Raffa ◽  
Fulvia Chiampo ◽  
Alberto Godio ◽  
Andrea Vergnano ◽  
Francesca Bosco ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Dielectric Permittivity ◽  
Response Surface ◽  
Reaction Rates ◽  
Diesel Oil ◽  
Second Order ◽  
Coaxial Cable ◽  
Oil Concentration ◽  
Two Parameters ◽  
Aerobic Bioremediation

This study aimed to investigate the kinetics of an aerobic bioremediation process of diesel oil removal by indigenous microorganisms, and to define the optimal operative conditions by means of response surface methodology. This was carried out by setting up a series of microcosms (200 g of soil), polluted with the same diesel oil concentration (70 g·kg−1 of soil), but with different water contents (u%) and carbon to nitrogen (C/N) ratios. The process was monitored by: (1) residual diesel oil concentration, to measure the removal efficiency, and (2) fluorescein production, to check the microbial activity. These two parameters were the objective variables used for the analysis of variance (ANOVA) and response surface methodology (RSM). The results allowed the interactions between u% and C/N to be defined and the optimal range to be adopted for each. The process kinetics was modeled with first- and second-order reaction rates; slightly better results were achieved for the second-order model in terms of parameter variability. Biological processes like degradation may have effects on dielectric properties of soil; an open-ended coaxial cable was used to measure the dielectric permittivity of microcosm matrices at the start and after 130 days of bioremediation. The evolution of the real and the imaginary components of dielectric permittivity provided results that supported the evidence of a biodegradation process in progress.

scholarly journals Integrated use of chemical and geophysical monitoring to study the diesel oil biodegradation in microcosms with different operative conditions

2021 ◽  
Author(s):  
Carla Maria Raffa ◽  
Andrea Vergnano ◽  
Fulvia Chiampo ◽  
Alberto Godio
Keyword(s):  
Dielectric Permittivity ◽  
Water Content ◽  
Removal Efficiency ◽  
Diesel Oil ◽  
Coaxial Cable ◽  
Imaginary Component ◽  
Oil Removal ◽  
Oil Biodegradation ◽  
Dry Soil ◽  
Two Parameters

AbstractThis study aimed to monitor the aerobic bioremediation of diesel oil-contaminated soil by measuring: a) the CO2 production; 2) the fluorescein production; 3) the residual diesel oil concentration. Moreover, the complex dielectric permittivity was monitored through an open-ended coaxial cable. Several microcosms were prepared, changing the water content (u% = 8–15% by weight), the carbon to nitrogen ratio (C/N = 20–450), and the soil amount (200 and 800 g of dry soil). The cumulative CO2 and fluorescein production showed similar trends, but different values since these two parameters reflect different features of the biological process occurring within each microcosm. The diesel oil removal efficiency depended on the microcosm characteristics. After 84 days, in the microcosms with 200 g of dry soil, the highest removal efficiency was achieved with a water content of 8% by weight and C/N = 120, while in the microcosms with 800 g of dry soil the best result was achieved with the water content equal to 12% by weight and C/N = 100. In the tested soil, the bioremediation process is efficient if the water content is in the range 8–12% by weight, and C/N is in the range 100–180; under these operative conditions, the diesel oil removal efficiency was about 65–70% after 84 days. The dielectric permittivity was monitored in microcosms with 200 g of dry soil. The open-ended coaxial cable detected significant variations of both the real and the imaginary component of the dielectric permittivity during the bioremediation process, due to the physical and chemical changes that occurred within the microcosms.

scholarly journals OPTIMIZATION OF LEVOFLOXACIN REMOVAL FROM AQUEOUS SOLUTION USING ELECTROCOAGULATION PROCESS BY RESPONSE SURFACE METHODOLOGY

2021 ◽  
Vol 52 (1) ◽  
pp. 204-217
Author(s):  
Mohammed & Mohammed-Ridha
Keyword(s):  
Aqueous Solution ◽  
Response Surface Methodology ◽  
Response Surface ◽  
Correlation Coefficient ◽  
Iron Hydroxide ◽  
Second Order ◽  
Experimental Results ◽  
Order Kinetic ◽  
Experimental Conditions ◽  
Good Agreement

This study was aimed to investigate the response surface methodology (RSM) to evaluate the effects of various experimental conditions on the removal of levofloxacin (LVX) from the aqueous solution by means of electrocoagulation (EC) technique with stainless steel electrodes. The EC process was achieved successfully with the efficiency of LVX removal of 90%. The results obtained from the regression analysis, showed that the data of experiential are better fitted to the polynomial model of second-order with the predicted correlation coefficient (pred. R2) of 0.723, adjusted correlation coefficient (Adj. R2) of 0.907 and correlation coefficient values (R2) of 0.952. This shows that the predicted models and experimental values are in good agreement. The results of the kinetic study showed that the second-order kinetic model was in good agreement with the experimental results and suggested that the mechanism of chemisorption controlled the LVX adsorption. The experimental results indicated that the adsorption of LVX on iron hydroxide flocs follows Sips isotherm with the value of the correlation coefficient (R2) of 0.937. Sips isotherm shows that both homogenous and heterogeneous adsorption can occur.

scholarly journals Application of Response Surface Methodology to Enhance Phenol Removal from Refinery Wastewater by Microwave Process

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Sherif A. Younis ◽  
Waleed I. El-Azab ◽  
Nour Sh. El-Gendy ◽  
Shuokr Qarani Aziz ◽  
Yasser M. Moustafa ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Output Power ◽  
Petroleum Refinery ◽  
Irradiation Time ◽  
Reaction Rates ◽  
Design Parameters ◽  
Phenol Removal ◽  
Refinery Wastewater ◽  
Petroleum Refinery Wastewater

Phenol contaminated petroleum refinery wastewater presents a great threat on water resources safety. This study investigates the effect of microwave irradiation on removal of different concentrations of phenol in an attempt for petroleum refinery wastewater treatment. The obtained results show that the MW output power and irradiation time have a significant positive effect on the removal efficiency of phenol. The kinetic reaction is significantly affected by initial MW output power and initial phenol concentrations. Response surface methodology (RSM) was employed to optimize and study the interaction effects of process parameters: MW output power, irradiation time, salinity, pH, and H2O2 concentration using central composite design (CCD). From the CCD design matrix, a quadratic model was considered as an ultimate model (R2 = 0.75) and its adequacy was justified through analysis of variance (ANOVA). The overall reaction rates were significantly enhanced in the combined MW/H2O2 system as proved by RSM. The optimum values for the design parameters of the MW/H2O2 process were evaluated giving predicted phenol removal percentage of 72.90% through RSM by differential approximation and were confirmed by experimental phenol removal of 75.70% in a batch experiment at optimum conditions of 439 W MW power, irradiation time of 24.22 min, salinity of 574 mg/L, pH 5.10, and initial H2O2 concentration of 10% (v/v).

scholarly journals Optimization of pyrocatechol violet biosorption by Robinia pseudoacacia leaf powder using response surface methodology: kinetic, isotherm and thermodynamic studies

2015 ◽  
Vol 6 (2) ◽  
pp. 333-344 ◽  
Author(s):  
Neda Khorshidi ◽  
Ali Niazi
Keyword(s):  
Response Surface Methodology ◽  
Factorial Design ◽  
Response Surface ◽  
Robinia Pseudoacacia ◽  
Freundlich Isotherm ◽  
Second Order ◽  
Full Factorial Design ◽  
Order Kinetic ◽  
Pyrocatechol Violet ◽  
Full Factorial

We have investigated the biosorption of pyrocatechol violet (PCV) from aqueous solutions by Robinia pseudoacacia tree leaves as a low-cost and eco-friendly biosorbent. A full factorial design was performed for screening the main variables and their interactions, which reduces the large total number of experiments. Results of the full factorial design (24) based on an analysis of variance (ANOVA) demonstrated that the initial PCV concentration, contact time, pH and temperature are statistically significant. Box-Behnken design, a response surface methodology, was used for further optimization of these selected factors. The ANOVA and some statistical tests such as lack-of-fit and coefficient of determination (R2) showed good fit of the experimental data to the second-order polynomial model. The Langmuir and Freundlich isotherm models were used to describe the equilibrium isotherms. Equilibrium data fitted well with the Freundlich isotherm model (R2 > 0.97). In addition, thermodynamic parameters (ΔG°, ΔH° and ΔS°) were calculated, these parameters show that the biosorption process was spontaneous (ΔG° = −2.423) and exothermic (ΔH° = −9.67). The biosorption kinetic data were fitted with the pseudo-second-order kinetic model (R2 > 0.999). These results confirm that R. pseudoacacia leaves have good potential for removal of PCV from aqueous solution.

Extraction of Flavonoids from Clovers

2012 ◽  
Vol 195-196 ◽  
pp. 360-363
Author(s):  
Chun Gang Chen ◽  
Fen Xia Han ◽  
Yuan Zhang ◽  
Yu Zhong Shi
Keyword(s):  
Response Surface Methodology ◽  
Optimum Condition ◽  
Central Composite Design ◽  
Response Surface ◽  
Ethanol Concentration ◽  
Response Surfaces ◽  
Second Order ◽  
Order Model ◽  
Solid Ratio ◽  
Central Composite

The extraction of flavonoids from clovers was optimized to maximize flavonoid yield Y in this study. A central composite design of response surface methodology involving extracting time, liquid-solid ratio, extracting temperature and ethanol concentration was used, and second-order model for Y was employed to generate the response surfaces. The optimum condition for Y was determined as follows: extracting time 24min, liquid-solid ratio 20, extracting temperature 80°C, and ethanol concentration 72%. Under the optimum condition, the flavonoid yield was 2.49%.

scholarly journals Combined Surfactant and Enzyme-Assisted Extraction of Pectin from Hawthorn (Crataegus monogyna Jacq.) Fruits

2022 ◽  
Vol 51 (4) ◽  
pp. 733-742
Author(s):  
Anastasia Novikova ◽  
Liubov Skrypnik
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Polynomial Regression ◽  
Polynomial Equation ◽  
Second Order ◽  
Wild Fruits ◽  
Assisted Extraction ◽  
Order Polynomial ◽  
Extraction Parameters ◽  
Enzyme Assisted Extraction

Introduction. Commercial pectin is usually obtained from apples or citrus fruits. However, some wild fruits, such as hawthorn, are also rich in pectin with valuable nutritional and medical properties. The research objective was to study and improve the process of combined surfactant and enzyme-assisted extraction of pectin from hawthorn fruits. Study objects and methods. The study involved a 1% solution of Polysorbate-20 surfactant and a mix of two enzymes, namely cellulase and xylanase, in a ratio of 4:1. The response surface methodology with the Box-Behnken experimental design improved the extraction parameters. The experiment featured three independent variables – temperature, time, and solvent-to-material ratio. They varied at three levels: 20, 40, and 60°C; 120, 180, and 240 min; 15, 30, and 45 mL per g. Their effect on the parameters on the pectin yield was assessed using a quadratic mathematical model based on a second order polynomial equation. Results and discussion. The response surface methodology made it possible to derive a second order polynomial regression equation that illustrated the effect of extraction parameters on the yield of polyphenols. The regression coefficient (R2 = 98.14%) and the lack-of-fit test (P > 0.05) showed a good accuracy of the model. The optimal extraction conditions were found as follows: temperature = 41°C, time = 160 min, solvent-to-material ratio = 32 mL per 1 g. Under the optimal conditions, the predicted pectin yield was 14.9%, while the experimental yield was 15.2 ± 0.4%. The content of galacturonic acid in the obtained pectin was 58.5%, while the degree of esterification was 51.5%. The hawthorn pectin demonstrated a good complex-building ability in relation to ions of copper (564 mg Cu2+/g), lead (254 mg Pb2+/g), and cobalt (120 mg Co2+/g). Conclusion. Combined surfactant and enzyme-assisted extraction made improved the extraction of pectin from hawthorn fruits. The hawthorn pectin can be used to develop new functional products.

Tool-Life Testing by Response Surface Methodology—Part 2

1964 ◽  
Vol 86 (2) ◽  
pp. 111-116 ◽  
Author(s):  
S. M. Wu
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Tool Life ◽  
Statistical Significance ◽  
Cutting Speed ◽  
Order Effect ◽  
Second Order ◽  
First Order ◽  
Independent Variable ◽  
Basic Philosophy

This paper is a continuation of a previous paper in which the basic philosophy of response surface methodology has been explained and a first-order tool-life-predicting equation has been developed. This part of the paper illustrates the development of a second-order tool-life-predicting equation in 18 and 24 tests. It was found that the second-order effect did not show statistical significance within the cutting ranges of this project; however, the second-order effect of cutting speed has been found important by the study of residuals. If only one independent variable is investigated, a minimal number of tests can be used to find a second-order equation. Examples of designs in three, five, and six tests are illustrated.

Boosting Mechanical Properties of Orthoses - Foot Ankle by Adding Carbon Nanotube Particles

2021 ◽  
Vol 1039 ◽  
pp. 518-536
Author(s):  
Abbas H. Jeryo ◽  
Jumaa S. Chiad ◽  
Wajdi S. Abbod
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Model Building ◽  
Fatigue Tests ◽  
Bending Test ◽  
Vacuum System ◽  
High Yield ◽  
Fatigue Properties ◽  
The Matrix ◽  
Two Parameters

In this process, optimum laminating properties were used in producing prosthesis and orthoses were researched and selected based on high yield, ultimate stresses, stresses of bending and fatigue properties. The process of the optimal selection is the Response Surface Methodology (RSM), which has been used to reach two parameters: reinforcement perlon fiber and percent of multi-strand carbon MWCNT nanotube combined with the matrix resin. The response surface methodology is a combination of mathematician and statistic techniques which are used for experimental model building and analysis of problems. This technique revealed 13 separate laminations samples with a percentage of separate Perlon layers No. and MWCNT Wt %. Tests were conducted for all lamination materials as defined in RSM methods and rendered by vacuum system, including fatigue tests for the ideal laminating material as opposed to laminations developed in the prior study (three Tensile test, Bending test and Fatigue tests according to the ASTM D638 and D790 respectively). Tests from the system version 10.0.2 of Design Expert found lamination (10 perlon layers and 0.75% of MWCNTs) to be the best according to overall yield, ultimate and bending loads in the 12 other laminations. Fatigue eventually revealed that constraints were applied to the stamina tension (2,66, 1,66) for optimum lamination, relative to ten perlon lamination layers and 424 lamination respectively.

scholarly journals Useful Numerical Statistics of Some Response Surface Methodology Designs

2016 ◽  
Vol 8 (4) ◽  
pp. 40
Author(s):  
Iwundu M. P.
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Optimality Criteria ◽  
Second Order ◽  
First Order ◽  
Central Composite Designs ◽  
Alphabetic Optimality ◽  
Main Effects ◽  
Composite Designs ◽  
Central Composite

<p>Useful numerical evaluations associated with three categories of Response Surface Methodology designs are presented with respect to five commonly encountered alphabetic optimality criteria. The first-order Plackett-Burman designs and the  Factorial designs are examined for the main effects models and the complete first-order models respectively. The second-order Central Composite Designs are examined for second-order models. The A-, D-, E-, G- and T-optimality criteria are employed as commonly encountered optimality criteria summarizing how good the experimental designs are. Relationships among the optimality criteria are pointed out with regards to the designs and the models. Generally the designs do not show uniform preferences in terms of the considered optimality criteria. However, one interesting finding is that central composite designs defined on cubes and hypercubes with unit axial distances are uniformly preferred in terms of E-optimality and G-optimality criteria.</p>

Optimization of Fermentation Process of Pear Vinegar by Response Surface Methodology

2011 ◽  
Vol 201-203 ◽  
pp. 2513-2516 ◽  
Author(s):  
Han Gao ◽  
Gui Fang Xu ◽  
Yuan Yuan Fan ◽  
Hai Juan Nan ◽  
Su Fang Fu
Keyword(s):  
Response Surface Methodology ◽  
Optimum Condition ◽  
Central Composite Design ◽  
Response Surface ◽  
Fermentation Process ◽  
Second Order ◽  
Order Model ◽  
Optimization Of Fermentation ◽  
Temperature Time ◽  
Central Composite

The fermentation process of pear vinegar was optimized to maximize the amount of acetate in this study. A central composite design of response surface methodology involving inoculation rate, temperature, time was used, and second-order model for the amount of acetate was employed to generate the response surface. The optimum condition for the fermentation process was determined as follows: inoculation rate 8.65 %, temperature 30.17 °C, time 7.44 d. The obtained amount of acetate at the optimum condition was 9.53%.

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