scholarly journals Response surface analysis on the effect of temperature and pH on Growth and proteolytic activity of thermophilic Bacillus sp

2010 ◽  
Vol 53 (5) ◽  
pp. 1067-1072 ◽  
Author(s):  
Krystyna Gorlach-Lira ◽  
Maria Lourdes Vieira Pedroza ◽  
Aleksandra Burdziej-Pokojska ◽  
Henryk Rozycki ◽  
Hanna Dahm
Keyword(s):  
Response Surface ◽  
Proteolytic Activity ◽  
Effect Of Temperature ◽  
Coefficient Of Determination ◽  
Bacillus Sp ◽  
P Values ◽  
Thermophilic Bacillus ◽  
Cell Biomass ◽  
Initial Ph ◽  
Statistic Model

Proteolytic activity and cell biomass of thermophilic Bacillus sp. strain were evaluated at various levels of initial pH and temperature by applying response surface methodology. The mineral medium containing yeast extract (0.01%) and starch (1%) was used throughout the experiment. The results of statistical analysis revealed the polynomial model with high coefficient of determination (R² = 0.8) for the biomass and total proteolytic activity of the strain studied. This model showed a satisfactory adjustment of the statistic model with the experimental data. The p values showed that the temperature and pH had significant effect on biomass and proteolytic activity (P<0.05) of strain tested. The highest proteolytic activity (2.333 U/ml/h) of the Bacillus sp. was predicted at 41º C and pH 4.8. The high biomass values were observed at broad range of temperature and pH.

scholarly journals Optimization of electrocoagulation of instant coffee production wastewater using the response surface methodology

2017 ◽  
Vol 19 (2) ◽  
pp. 67-71 ◽  
Author(s):  
Ha Manh Bui
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Removal Efficiency ◽  
Current Density ◽  
Cod Removal ◽  
Coefficient Of Determination ◽  
Electrolysis Time ◽  
Instant Coffee ◽  
Operating Variables ◽  
Initial Ph

Abstract The COD removal efficiency from an instant coffee processing wastewater using electrocoagulation was investigated. For this purpose, the response surface methodology was employed, using central composing design to optimize three of the most important operating variables, i.e., electrolysis time, current density and initial pH. The results based upon statistical analysis showed that the quadratic models for COD removal were significant at very low probability value (<0.0001) and high coefficient of determination (R2 = 0.9621) value. The statistical results also indicated that all the three variables and the interaction between initial pH and electrolysis time were significant on COD abatement. The maximum predicted COD removal using the response function reached 93.3% with electrolysis time of 10 min, current density of 108.3 A/m2 and initial pH of 7.0, respectively. The removal efficiency value was agreed well with the experimental value of COD removal (90.4%) under the optimum conditions.

scholarly journals Optimisation of the Maillard reaction of bovine gelatine-xylose model using response surface methodology

Food Research ◽  
2020 ◽  
Vol 4 (S1) ◽  
pp. 99-106 ◽  
Author(s):  
I. Ismarti ◽  
K. Triyana ◽  
N.A. Fadzilah ◽  
H.M. Salleh ◽  
N.F.H. Nordin
Keyword(s):  
Response Surface ◽  
Maillard Reaction ◽  
Heating Time ◽  
Coefficient Of Determination ◽  
Maillard Reaction Products ◽  
Reaction Products ◽  
Adequate Model ◽  
Surface Method ◽  
Initial Ph ◽  
Halal Authentication

The Maillard reaction is known as an amino-carbonyl reaction or non-enzymatic browning reaction which has an essential role in food processing to improve the appearance, taste and functional properties of food. In halal authentication, results could be used to differentiate the sources of gelatine based on the colour and flavour. Since many factors can influence the reaction, it is important to study and optimize the Maillard reaction in a gelatine model system using response surface method, applied to optimize the processing of bovine gelatine-xylose to improve the Maillard reaction products. In this study, the effects of initial pH, temperature, and heating time to browning intensity of melanoidin were evaluated. The increasing of initial pH, temperature and heating time were associated with an enhanced browning intensity of Maillard reaction products. This study demonstrated that the coefficient of determination 0.8429 reveals the response surface reduced linear model is an adequate model for browning intensity of Maillard reaction of the bovine gelatine-xylose system. For a system with 5% of gelatine solution and 0.75 g of xylose, the optimum condition for the browning process obtained was initial of pH 10.92, temperature of 140°C and heating time of 37.28 mins. The predicted results at optimum conditions coincided well with the experimental value with the relative error of less than 5%.

scholarly journals Optimization of electrocoagulation operating parameters for COD removal from olive mill wastewater: application of Box-Behnken design

2019 ◽  
Vol 9 (3) ◽  
pp. 212-221
Author(s):  
Fatima Erraib ◽  
Khalid El Ass
Keyword(s):  
Response Surface ◽  
Chloride Concentration ◽  
Oxygen Demand ◽  
Olive Mill Wastewater ◽  
Operating Conditions ◽  
Cod Removal ◽  
Coefficient Of Determination ◽  
Box Behnken Design ◽  
Initial Ph ◽  
Olive Mill

Box–Behnken response surface design was successfully employed to optimize and study the olive mill wastewater (OMW) treatment by electrocoagulation (EC) process. The influence of four decisive factors were modelled and optimized to increase the removal of chemical oxygen demand (COD). The Box–Behnken design (BBD) results were analyzed and the second-order polynomial model was developed using multiple regression analysis. The model developed from the experimental design was predictive and a good fit with the experimental data with a high coefficient of determination (R2 ) value (more than 0.98). The optimal operating conditions based on Derringer’s desired function methodology are found to be; initial pH of 4.4, a current density of 27.6 mA/cm2 , electrolysis time of 14.1 min, and chloride concentration of 3.2 g/L. Under these conditions, the predicted COD removal efficiency was found to be 67.14% with a desirability value of 0.94. These experimental results were confirmed by validation experiments and proved that Box–Behnken design and response surface methodology could efficiently be applied for modelling of COD removal from OMW.

Optimization of Naphthalene Extraction from its Mixture with Base Oil and Dibenzothiophene by BMIMDMP Ionic Liquid Using Response Surface Methodology (RSM)

2014 ◽  
Vol 625 ◽  
pp. 50-56
Author(s):  
Ghassan M.J. Al Kaisy ◽  
Mohamed I.A. Mutalib ◽  
Mohd Azmi Bustam ◽  
Radzuan B. Razali
Keyword(s):  
Response Surface Methodology ◽  
Ionic Liquid ◽  
Response Surface ◽  
Extraction Process ◽  
Performance Model ◽  
Effect Of Temperature ◽  
Coefficient Of Determination ◽  
Base Oil ◽  
Series Of Experiments ◽  
The Relationship

– In this study, the Response Surface Methodology (RSM) was applied for optimizing the extraction process of Naphthalene from its mixture with Base Oil and Dibenzothiophene using the ionic liquid 1-Butyl-3-Methyimidazolium Dimethylphosphate (BMIMDMP). The series of experiments conducted were designed using Design Expert version 8.7.0.1 software for studying the effect of temperature and ionic liquid to oil mass ratio on the performance of naphthalene removal. The Analysis of Variance (ANOVA) conducted to determine the relationship developed for the two variables above with respect to the naphthalene removal showed a high coefficient of determination (R2) value of (0.9998) hence indicating a very good performance model which can be used for optimizing the extraction process. Based on the results, it shows that 67% percent removal could be achieved with one extraction stage at the optimum condition.

scholarly journals Anaerobic Acidogenic Fermentation of Cellobiose by Immobilized Cells: Prediction of Organic Acids Production by Response Surface Methodology

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1441
Author(s):  
Panagiota Tsafrakidou ◽  
Konstantina Tsigkou ◽  
Argyro Bekatorou ◽  
Maria Kanellaki ◽  
Athanasios A. Koutinas
Keyword(s):  
Response Surface Methodology ◽  
Organic Acids ◽  
Response Surface ◽  
Lignocellulosic Biomass ◽  
Immobilized Cells ◽  
Effect Of Temperature ◽  
Quadratic Effect ◽  
Linear Effect ◽  
Acidogenic Fermentation ◽  
Initial Ph

Response surface methodology was used to derive a prediction model for organic acids production by anaerobic acidogenic fermentation of cellobiose, using a mixed culture immobilized on γ-alumina. Three parameters (substrate concentration, temperature, and initial pH) were evaluated. In order to determine the limits of the parameters, preliminary experiments at 37 °C were conducted using substrates of various cellobiose concentrations and pH values. Cellobiose was used as a model sugar for subsequent experiments with lignocellulosic biomass. The culture was well adapted to cellobiose by successive subculturing at 37 °C in synthetic media (with 100:5:1 COD:N:P ratio). The experimental data of successive batch fermentations were fitted into a polynomial model for the total organic acids concentration in order to derive a predictive model that could be utilized as a tool to predict fermentation results when lignocellulosic biomass is used as a substrate. The quadratic effect of temperature was the most significant, followed by the quadratic effect of initial pH and the linear effect of cellobiose concentration. The results corroborated the validity and effectiveness of the model.

scholarly journals Optimisation of Reactive Black 5 dye removal by electrocoagulation process using response surface methodology

2016 ◽  
Vol 75 (4) ◽  
pp. 952-962 ◽  
Author(s):  
W. T. Mook ◽  
M. K. Aroua ◽  
M. Szlachta ◽  
C. S. Lee
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Treatment Time ◽  
Textile Wastewater ◽  
Coefficient Of Determination ◽  
Percentage Error ◽  
Reactive Black 5 ◽  
Solution Ph ◽  
Initial Ph ◽  
Electrocoagulation Process

In this work, a regression model obtained from response surface methodology (RSM) was proposed for the electrocoagulation (EC) treatment of textile wastewater. The Reactive Black 5 dye (RB5) was used as a model dye to evaluate the performance of the model design. The effect of initial solution pH, applied current and treatment time on RB5 removal was investigated. The total number of experiments designed by RSM amounted to 27 runs, including three repeated experimental runs at the central point. The accuracy of the model was evaluated by the F-test, coefficient of determination (R2), adjusted R2 and standard deviation. The optimum conditions for RB5 removal were as follows: initial pH of 6.63, current of 0.075 A, electrolyte dose of 0.11 g/L and EC time of 50.3 min. The predicted RB5 removal was 83.3% and the percentage error between experimental and predicted results was only 3–5%. The obtained data confirm that the proposed model can be used for accurate prediction of RB5 removal. The value of the zeta potential increased with treatment time, and the X-ray diffraction pattern shows that iron complexes were found in the sludge.

scholarly journals Land surface model photosynthesis and parameter calibration for boreal sites with adaptive population importance sampler

2019 ◽  
Author(s):  
Jarmo Mäkelä ◽  
Jürgen Knauer ◽  
Mika Aurela ◽  
Andrew Black ◽  
Martin Heimann ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Land Surface ◽  
Carbon Fixation ◽  
Gross Primary Production ◽  
Effect Of Temperature ◽  
Coefficient Of Determination ◽  
Surface Model ◽  
Drought Event ◽  
Forest Site ◽  
Delayed Effect

Abstract. We calibrated the JSBACH model with six different stomatal conductance formulations using measurements from 10 FLUXNET coniferous evergreen sites in the Boreal zone. The parameter posterior distributions were generated by adaptive population importance sampler and the optimal values by a simple stochastic optimisation algorithm. The observations used to constrain the model are evapotranspiration (ET) and gross primary production (GPP). We identified the key parameters in the calibration process. These parameters control the soil moisture stress function and the overall rate of carbon fixation. We were able to improve the coefficient of determination and the model bias with all stomatal conductance formulations. There was no clear candidate for the best stomatal conductance model, although certain versions produced better estimates depending on the examined variable (ET, GPP) and the used metric. We were also able to significantly enhance the model behaviour during a drought event in a Finnish Scots pine forest site. The JSBACH model was also modified to use a delayed effect of temperature for photosynthetic activity. This modification enabled the model to correctly time and replicate the springtime increase in GPP (and ET) for conifers throughout the measurements sites used in this study.

scholarly journals Optimization of Crude Oil and PAHs Degradation by Stenotrophomonas rhizophila KX082814 Strain through Response Surface Methodology Using Box-Behnken Design

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Praveen Kumar Siddalingappa Virupakshappa ◽  
Manjunatha Bukkambudhi Krishnaswamy ◽  
Gaurav Mishra ◽  
Mohammed Ameenuddin Mehkri
Keyword(s):  
Response Surface Methodology ◽  
Crude Oil ◽  
Response Surface ◽  
Oxygen Demand ◽  
Inoculum Size ◽  
Coefficient Of Determination ◽  
Oil Removal ◽  
Box Behnken Design ◽  
Stenotrophomonas Rhizophila ◽  
Crude Oil Removal

The present paper describes the process optimization study for crude oil degradation which is a continuation of our earlier work on hydrocarbon degradation study of the isolate Stenotrophomonas rhizophila (PM-1) with GenBank accession number KX082814. Response Surface Methodology with Box-Behnken Design was used to optimize the process wherein temperature, pH, salinity, and inoculum size (at three levels) were used as independent variables and Total Petroleum Hydrocarbon, Biological Oxygen Demand, and Chemical Oxygen Demand of crude oil and PAHs as dependent variables (response). The statistical analysis, via ANOVA, showed coefficient of determination R2 as 0.7678 with statistically significant P value 0.0163 fitting in second-order quadratic regression model for crude oil removal. The predicted optimum parameters, namely, temperature, pH, salinity, and inoculum size, were found to be 32.5°C, 9, 12.5, and 12.5 mL, respectively. At this optimum condition, the observed and predicted PAHs and crude oil removal were found to be 71.82% and 79.53% in validation experiments, respectively. The % TPH results correlate with GC/MS studies, BOD, COD, and TPC. The validation of numerical optimization was done through GC/MS studies and   % removal of crude oil.

Electrocoagulation and nanofiltration integrated process application in purification of bilge water using response surface methodology

2016 ◽  
Vol 74 (3) ◽  
pp. 564-579 ◽  
Author(s):  
Ceyhun Akarsu ◽  
Yasin Ozay ◽  
Nadir Dizge ◽  
H. Elif Gulsen ◽  
Hasan Ates ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Removal Efficiency ◽  
Cod Removal ◽  
Positive Sign ◽  
Aluminum Electrode ◽  
Integrated Process ◽  
Bilge Water ◽  
Cod Removal Efficiency ◽  
Initial Ph

Marine pollution has been considered an increasing problem because of the increase in sea transportation day by day. Therefore, a large volume of bilge water which contains petroleum, oil and hydrocarbons in high concentrations is generated from all types of ships. In this study, treatment of bilge water by electrocoagulation/electroflotation and nanofiltration integrated process is investigated as a function of voltage, time, and initial pH with aluminum electrode as both anode and cathode. Moreover, a commercial NF270 flat-sheet membrane was also used for further purification. Box–Behnken design combined with response surface methodology was used to study the response pattern and determine the optimum conditions for maximum chemical oxygen demand (COD) removal and minimum metal ion contents of bilge water. Three independent variables, namely voltage (5–15 V), initial pH (4.5–8.0) and time (30–90 min) were transformed to coded values. The COD removal percent, UV absorbance at 254 nm, pH value (after treatment), and concentration of metal ions (Ti, As, Cu, Cr, Zn, Sr, Mo) were obtained as responses. Analysis of variance results showed that all the models were significant except for Zn (P &gt; 0.05), because the calculated F values for these models were less than the critical F value for the considered probability (P = 0.05). The obtained R2 and Radj2 values signified the correlation between the experimental data and predicted responses: except for the model of Zn concentration after treatment, the high R2 values showed the goodness of fit of the model. While the increase in the applied voltage showed negative effects, the increases in time and pH showed a positive effect on COD removal efficiency; also the most effective linear term was found as time. A positive sign of the interactive coefficients of the voltage–time and pH–time systems indicated synergistic effect on COD removal efficiency, whereas interaction between voltage and pH showed an antagonistic effect.

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