scholarly journals Optimization of Enhanced Ultrafiltration Conditions for Cd with Mixed Biosurfactants Using the Box-Behnken Response Surface Methodology

Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 442 ◽  
Author(s):  
Tian Chai ◽  
Huizhi Yan ◽  
Zhibin Zhang ◽  
Min Xu ◽  
Yicheng Wu ◽  
...  

A mixture of the environmentally friendly biosurfactants rhamnolipids and sophorolipids was used as a source of micelles in this study. The Box-Behnken design and response surface methodology was used to investigate the influence of factors on micellar-enhanced ultrafiltration (MEUF). Simulated Cd-containing wastewater was used for testing. Based on single-factor experiments, the initial Cd2+ concentration, biosurfactant mixing ratio (α) and pH were chosen as influential variables, and both the Cd2+ rejection coefficient and permeation flux were used as responses. A predictive model based on a quadratic polynomial regression equation was established to determine the optimized enhanced ultrafiltration conditions for Cd. The results show that the regression equation is extremely significant and fits the data accurately. The optimal enhanced ultrafiltration conditions are as follows: initial Cd2+ concentration of 10.0 mg/L, α of 0.30 and pH of 9.58. Under these conditions, the rejection coefficient and the permeation flux of Cd2+ are 99.14% and 37.36 L/m2·h, respectively. The experimental results confirm that the experimental values agree well with the values predicted by the model. Further, these results provide theoretical support for using MEUF to treat heavy metal-containing wastewater when biosurfactants are used for micelle formation.

2017 ◽  
Vol 68 (2) ◽  
pp. 331-336
Author(s):  
Gabriela Isopencu ◽  
Mirela Marfa ◽  
Iuliana Jipa ◽  
Marta Stroescu ◽  
Anicuta Stoica Guzun ◽  
...  

Nigella sativa, also known as black cumin, an annual herbaceous plant growing especially in Mediterranean countries, has recently gained considerable interest not only for its use as spice and condiment but also for its healthy properties of the fixed and essential oil and its potential as a biofuel. Nigella sativa seeds fixed oil, due to its high content in linoleic acid followed by oleic and palmitic acid, could be beneficial to human health. The objective of this study is to determine the optimum conditions for the solvent extraction of Nigella sativa seeds fixed oil using a three-level, three-factor Box-Behnken design (BBD) under response surface methodology (RSM). The obtained experimental data, fitted by a second-order polynomial equation were analysed by Pareto analysis of variance (ANOVA). From a total of 10 coefficients of the statistical model only 5 are important. The obtained experimental values agreed with the predicted ones.


Author(s):  
Wissam Zam ◽  
Ali Ali ◽  
Dimah Saleem ◽  
Sahar Alali

In recent years, Centaurium erythraea extracts have attracted much research attention in the context of prevention or treatment of many diseases due to its bioactive compounds content and antioxidant activity. The antioxidants of C. erythraea are very effective as they possess excellent antioxidant activity. Thus, it can be used as a safe and natural food preservative. The aim of this study is to make extracts more effective by optimizing the extraction conditions of the phenolics and antioxidants from C. erythraea using response surface methodology (RSM) based on a central composite design (CCD). Two process variables (Methanol volume fraction and solid - solvent ratio) were evaluated at five levels (13 experimental designs). Multiple regression analyses were performed to obtain quadratic polynomial equations using RSM; each response was fitted by a quadratic model. The adequacy of the models was proven using the analysis of variance (ANOVA). The significant effects of the factors and their interactions on the extraction efficiency were investigated at 95% confidence interval. RSM indicated that the optimal extraction conditions were 71% methanol volume fraction and 2.2:10 solid:solvent ratio. Predicted values thus obtained were close to the experimental values indicating suitability of the model.


Molecules ◽  
2019 ◽  
Vol 24 (4) ◽  
pp. 711 ◽  
Author(s):  
Arief Md Yusof ◽  
Siti Abd Gani ◽  
Uswatun Zaidan ◽  
Mohd Halmi ◽  
Badrul Zainudin

This study investigates the ultrasound-assisted extraction of flavonoids from Malaysian cocoa shell extracts, and optimization using response surface methodology. There are three variables involved in this study, namely: ethanol concentration (70–90 v/v %), temperature (45–65 °C), and ultrasound irradiation time (30–60 min). All of the data were collected and analyzed for variance (ANOVA). The coefficient of determination (R2) and the model was significant in interaction between all variables (98% and p < 0.0001, respectively). In addition, the lack of fit test for the model was not of significance, with p > 0.0684. The ethanol concentration, temperature, and ultrasound irradiation time that yielded the maximum value of the total flavonoid content (TFC; 7.47 mg RE/g dried weight (DW)) was 80%, 55 °C, and 45 min, respectively. The optimum value from the validation of the experimental TFC was 7.23 ± 0.15 mg of rutin, equivalent per gram of extract with ethanol concentration, temperature, and ultrasound irradiation time values of 74.20%, 49.99 °C, and 42.82 min, respectively. While the modelled equation fits the data, the T-test is not significant, suggesting that the experimental values agree with those predicted by the response surface methodology models.


e-Polymers ◽  
2011 ◽  
Vol 11 (1) ◽  
Author(s):  
P. Agarwal ◽  
A. Mondal ◽  
P.K. Mishra ◽  
P. Srivastava

AbstractThe present work describes the statistical process optimization of a lowcost production process of PLA using organometallic (stannous octoate) compounds. The process optimization for both lactide and polylactide, was developed by factorial design and response surface methodology. The influence of different experimental parameters such as reaction temperature, time, concentration of catalyst and co-initiator concentration on the yield of lactide and polylactide has been evaluated. There are many studies reported on the synthesis of polylactide but no earlier study exists for the application of statistical analysis in determining the interactions among the process variables for lactide and polylactide production. Central composite experimental design with multiple linear regression has been used to estimate the coefficients of the polynomial model equation for the yield(s) of both lactide and polylactide. The statistical significance of polynomial model equation was validated by F test (ANOVA). Determination coefficient (R2) values found to be 0.913 and 0.958 for lactide and polylactide respectively, states that predicted values were in good agreement with the experimental values. Results of the statistical analysis showed that the model fits in all cases. Above synthesised polymer was characterized by FT-IR, 1H-NMR, DSC and GPC to confirm the polymer structure and properties.


Author(s):  
Ganapati D. Yadav ◽  
Somnath Dattatray Shinde

Abstract Response surface methodology (RSM) was used to model and optimize the immobilized Candida antarctica lipase B catalysed synthesis of butyl-4-methyl-3-oxopentanoate. To determine optimum conditions of the transesterification, a four-factor and five-level central composite rotatable design (CCRD) was used. The factors studied were enzyme load (A), reaction temperature (B), methyl-4-methyl-3-oxopentanoate concentration (C) and n-butanol concentration (D). A quadratic polynomial regression model was used to analyze the experimental data at a 95% confidence level (p < 0.05). The results indicated that the RSM approach gave reasonable results for the optimization of the reaction parameters in the range of tested parameters. The optimal conditions for the enzymatic reaction were obtained at 0.01 mol of methyl-4-methyl-3-oxopentanoate and 0.03 mol of n-butanol using 104 mg of Novozym 435 at 55 °C and 300 rpm for 6 h. Under these conditions, the transesterification percentage was 87 %. Further, kinetic modelling of the enzymatic synthesis was illustrated. Initial rate data and progress curve data were used to arrive at a suitable model. The kinetics was found to obey the ternary complex ordered bi-bi model with inhibition by the substrate methyl-4-methyl-3-oxopentanoate. The values of kinetic parameters obtained from nonlinear regression analysis were found to be Vmax of 0.04 mol/L.min; Km(A) 0.11 mol/L; Km(B) 2 mol/L and Ki(A) 2.2 mol/L.


2013 ◽  
Vol 746 ◽  
pp. 380-384 ◽  
Author(s):  
Hui Zi Fu ◽  
Yong Zhu Cui ◽  
Wang Xiao ◽  
Li Hua Lv

In the present work, dye-free, salt-free coloration in wool fabric was studied. Response surface methodology (RSM) was used to develop predictive models for simulation and optimization of the color index a*b*ΔE. The influence of the viriables (sulfuric acid concentration,dyeing time ,dyeing temperature and concentration of DMBA) were investigated with the help of MINITAB16 software. The modeling methodologies was statisticallyanalysed by the coefficient of determination (R2), Correlation Coefficient values and Correlation Coefficient values. Results indicated excellent performance of experimental data by polynomial regression model.Finally, the corresponding effects of the independent viariables were studied by the analysis of variance (ANOVA).


Author(s):  
K. Boujounoui ◽  
A. Abidi ◽  
A. Baçaoui ◽  
K. El Amari ◽  
A. Yaacoubi

SYNOPSIS Response surface methodology (RSM), central composite design (CCD), and desirability functions were used for modelling and optimization of the operating factors in chlorite and talc (collectively termed 'mica') flotation. The influence of pulp pH, cyanide (NaCN) consumption, and particle size was studied with the aim of optimizing ssilicate flotation while minimizing recoveries of galena, chalcopyrite, and sphalerite. Flotation tests were carried out on a representative sample of a complex sulphide ore from Draa Sfar mine (Morocco). The model predictions for the flotation of each of the minerals concerned were found to be in good agreement with experimental values, with R2 values of 0.91, 0.98, 0.99, and 0.90 for mica, galena, chalcopyrite, and sphalerite recoveries, respectively. RSM combined with desirability functions and CCD was successfully applied for the modelling of mica flotation, considering simultaneously the four flotation responses to achieve the maximum recovery of mica and minimal loss of Pb, Cu, and Zn to the flotation concentrate. Keywords: chlorite, talc, flotation, response surface methodology, central composite design, optimization.


2019 ◽  
Vol 2 (1) ◽  
pp. 332-342
Author(s):  
Ha Thi Ngoc Lai ◽  
Phuong Viet Nguyen ◽  
Hoai Thi Tran ◽  
Viet Ha Thi Dao ◽  
Ha Hai Hoang

Chlorogenic acid is a natural antioxidant that is widespread in the plant kingdom and can be found at a high content level in green coffee beans. This secondary metabolite in green coffee beans has potent biological properties including antioxidant, anti-inflammatory, anti-cancer, anti-obesity, anti-hypertension, and anticonvulsant. In this study, the extraction of chlorogenic acid from Vietnamese green coffee beans was optimized using the response surface methodology. A second-order polynomial model with three important variables (liquid-to-solid ratio, temperature, and extraction time) was used. A rotatable central composite design consisting of 21 experimental runs with three replicates at the center point was applied to describe the experimental data. The experimental results properly conformed to the constructed model (R2 = 0.8549). The optimized conditions were as follows: 40% ethanol (v/v), a liquid-to-solid ratio of 11.77, at 85oC for 64 min. Four extractions were performed in parallel using the optimal conditions to validate the model. The experimental values highly agreed with the predicted value (P <0.05).


Separations ◽  
2021 ◽  
Vol 8 (9) ◽  
pp. 134
Author(s):  
Nenghui Li ◽  
Jing Li ◽  
Dongxia Ding ◽  
Jianming Xie ◽  
Jing Zhang ◽  
...  

To determine the optimum parameters for extracting three carotenoids including zeaxanthin, lutein epoxide, and violaxanthin from pepper leaves by response surface methodology (RSM), a solvent of acetone and ethyl acetate (1:2) was used to extract carotenoids with four independent factors: ultrasound time (20–60 min); ratio of sample to solvent (1:12–1:4); saponification time (10–50 min); and concentration of saponification solution (KOH–methanol) (10–30%). A second-order polynomial model produced a satisfactory fitting of the experimental data with regard to zeaxanthin (R2 = 75.95%, p < 0.0197), lutein epoxide (R2 = 90.24%, p < 0.0001), and violaxanthin (R2 = 73.84%, p < 0.0809) content. The optimum joint extraction conditions of zeaxanthin, lutein epoxide, and violaxanthin were 40 min, 1:8, 32 min, and 20%, respectively. The optimal predicted contents for zeaxanthin (0.823022 µg/g DW), lutein epoxide (4.03684 µg/g dry; DW—dry weight), and violaxanthin (16.1972 µg/g DW) in extraction had little difference with the actual experimental values obtained under the optimum extraction conditions for each response: zeaxanthin (0.8118 µg/g DW), lutein epoxide (3.9497 µg/g DW), and violaxanthin (16.1590 µg/g DW), which provides a theoretical basis and method for cultivating new varieties at low temperatures and weak light resistance.


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