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.

Supercritical CO2 Extraction of Plumula nelumbinis Oil Rich in γ-Sitosterol Using Response Surface Methodology

2013 ◽  
Vol 864-867 ◽  
pp. 213-216
Author(s):  
Dong Dong Jia ◽  
Rong Lan ◽  
Yong Yue Sun
Keyword(s):  
Response Surface Methodology ◽  
Factorial Design ◽  
Response Surface ◽  
Surface Analysis ◽  
Full Factorial Design ◽  
Response Surface Analysis ◽  
Optimal Conditions ◽  
Full Factorial

Supercritical CO2extraction ofPlumula nelumbinisoil rich in γ-sitosterol was investigated with a 42full factorial design and response surface analysis. At optimal conditions (P=35 MPa,T=55 C,dp=0.22 mm,Q=2.0 L/min), the yield of the extracted oil was up to 12.2%, in which the concentration of γ-sitosterol was 7.38%, indicating that the γ-sitosterol contents inPlumula nelumbinisand its oil were much higher than that in other vegetables.

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 Adsorption of Remazol Brillant Green 6B (RBG 6B) on chitin: process optimization using response surface methodology

2018 ◽  
Vol 20 (2) ◽  
pp. 257-268 ◽  
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Removal Efficiency ◽  
Dye Removal ◽  
Freundlich Isotherm ◽  
Sem Analysis ◽  
Second Order ◽  
Operating Conditions ◽  
Coefficient Of Determination ◽  
Solution Ph

In the present study, the adsorption of Remazol Brillant Green 6B (RBG 6B) on chitin which characterized by BET, FTIR, XRD and SEM analysis was studied. Response surface methodology (RSM) was applied to determine interaction between solution pH, initial RBG 6B concentration and chitin dosage being individual variables and to optimize operating conditions. According to results of variance analysis (ANOVA), the second order polynomial model was statistically significant (P<0.0001) and coefficient of determination value (R2=0.98) was high. It was determined that dye removal efficiency increased when low solution pH and initial RBG 6B dye concentration and high chitin dosage were used. The maximum dye removal efficiency was obtained as 88% at solution pH of 3.0, initial RBG 6B concentration of 75 mg L-1 and chitin dosage of 5.0 g L-1. The isotherms and kinetics studies showed that Freundlich isotherm and pseudo-second-order kinetics model fitted well to the RBG 6B adsorption data.

Three-level response surface full-factorial design: advanced chemometric approach for optimizing diclofenac sodium-imprinted polymer

2013 ◽  
Vol 71 (1) ◽  
pp. 19-30 ◽  
Author(s):  
Nasim Salimraftar ◽  
Saeed Noee ◽  
Majid Abdouss ◽  
Gholamhossein Riazi ◽  
Zahra Monsef Khoshhesab
Keyword(s):  
Factorial Design ◽  
Response Surface ◽  
Diclofenac Sodium ◽  
Full Factorial Design ◽  
Imprinted Polymer ◽  
Chemometric Approach ◽  
Full Factorial

Earphone terminal quality improvement through sequential experimental design

2015 ◽  
Vol 32 (7) ◽  
pp. 693-702 ◽  
Author(s):  
Zhen He ◽  
Xu-tao Zhang ◽  
Gui-qing Xie ◽  
Min Zhang
Keyword(s):  
Factorial Design ◽  
Response Surface ◽  
Response Surface Model ◽  
Full Factorial Design ◽  
Fractional Factorial ◽  
Surface Model ◽  
Quality Performance ◽  
Content Type ◽  
Input Variables ◽  
Full Factorial

Purpose – The purpose of this paper is to improve the key quality performance of the terminal of earphone in an electronic company. Design/methodology/approach – Sequential experimental designs are employed. Significant input variables are found through a full factorial design. Then a response surface model is constructed considering curvature in the linear model. Findings – Optimized key input variables’ parameters are found using the response surface model. The key quality performance, coplanarity of the terminal of earphone has been improved. Research limitations/implications – Instead of running a full factorial design in the first stage, a fractional factorial may be used to reduce experimental runs. Practical implications – The paper presents a good solution for reducing defects caused by large coplanarity of a kind of earphone terminal. Originality/value – The methodology used in this case can be easily extended to similar cases.

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