Modeling of phenol adsorption isotherm onto activated carbon by non-linear regression methods: models with three and four parameters

2018 ◽  
Vol 136 ◽  
pp. 199-206
Author(s):  
Donald Raoul Tchuifon Tchuifon ◽  
George Nche Ndifor-Angwafor ◽  
Aurelien Bopda ◽  
Solomon Gabche Anagho
Keyword(s):  
Activated Carbon ◽  
Adsorption Isotherm ◽  
Linear Regression ◽  
Phenol Adsorption ◽  
Regression Methods ◽  
Non Linear

scholarly journals Progress-curve equations for reversible enzyme-catalysed reactions inhibited by tight-binding inhibitors

1990 ◽  
Vol 265 (3) ◽  
pp. 647-653 ◽  
Author(s):  
S E Szedlacsek ◽  
V Ostafe ◽  
R G Duggleby ◽  
M Serban ◽  
M O Vlad
Keyword(s):  
Linear Regression ◽  
Competitive Inhibition ◽  
Tight Binding ◽  
The Other ◽  
First Order ◽  
Regression Methods ◽  
Progress Curve ◽  
Dead End ◽  
Non Linear ◽  
Inhibition Constants

The rate equation for a tight-binding inhibitor of an enzyme-catalysed first-order reversible reaction was used to derive two integrated equations. One of them covers the situations in which competitive, uncompetitive or non-competitive inhibition occurs and the other refers to the special non-competitive case where the two inhibition constants are equal. For these equations, graphical and non-linear regression methods are proposed for distinguishing between types of inhibition and for calculating inhibition constants from progress-curve data. The application of the non-linear regression to the analysis of stimulated progress curves in the presence of a tight-binding inhibitor is also presented. The results obtained are valid for any type of ‘dead-end’-complex-forming inhibitor and can be used to characterize an unknown inhibitor on the basis of progress curves.

scholarly journals Comparative analysis of linear and nonlinear equilibrium models for the removal of metronidazole by tea waste activated carbon

2020 ◽  
Vol 82 (7) ◽  
pp. 1484-1494
Author(s):  
Peter Emmanuel Ebili ◽  
Manase Auta ◽  
Kehinde Shola Obayomi ◽  
Joseph Onyebuchi Okafor ◽  
Muibat Diekola Yahya ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Adsorption Isotherm ◽  
Active Sites ◽  
Linear Models ◽  
Physical Adsorption ◽  
Freundlich Isotherm ◽  
Cost Effective ◽  
Chi Square ◽  
Tea Waste ◽  
Non Linear

Abstract Tea waste was carbonized at 400 °C for 45 min and modified with potassium hydroxide (KOH), to enhance the active sites for the adsorption of antibiotics. The developed tea waste activated carbon (TWAC) was used as a novel eco-friendly and cost-effective adsorbent for metronidazole (MZN) removal from aqueous solution. The textural and surface properties of the adsorbent were determined using Brunauer-Emmett-Teller (BET) and FT-Raman analysis. The BET surface was found to have increased from 24.670 to 349.585 after carbonization and KOH modification. The batch experimental parameters were optimized and equilibrium time was found to be 75 min. Linear and non-linear models were carried out on the adsorption isotherm and kinetics to determine the best fit for the adsorption data. The adsorption equilibrium data were well fitted by the Freundlich isotherm and pseudo-second order models, with higher regression correlation (R2) and smaller chi-square (χ2), as predicted by the non-linear model. The thermodynamic results revealed the adsorption of MZN as spontaneous, physical, and consistently exothermic in character. The activation energy value of 7.610 kJ/mol further revealed that the adsorption process is dominated majorly by physical adsorption. The removal of MZN onto TWAC was best described by the non-linear adsorption isotherm and kinetics model.

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