Author/Authors :
gharsalli, amor national engineering school of gabes - department of chemical engineering, Tunisia , bagane, mohamed national engineering school of gabes - department of chemical engineering, Tunisia , porte, catherine conservatoire national des arts et métiers - laboratoire de génie des procédés pour l’environnement, l’énergie et la santé (lgpees-ea21), France , havet, jean louis conservatoire national des arts et métiers - laboratoire de génie des procédés pour l’environnement, l’énergie et la santé (lgpees-ea21), France , ammar, salah university of gabes - faculty of science - department of chemistry, Tunisia
Abstract :
In this work, a bentonite activation processes with ammonium chloride were investigated using the Response Surface Methodology (RSM). The specific surface areas (SBET) of the treated samples were chosen as the process response. The effect of four independent factors; namely activation temperature (50-90°C), contact time (2-6h), liquid-to-solid mass ratio (4-7g/g) and ammonium chloride concentration (1-2 mol L-1) on the process response were determined. A basic experimental design has been done according to a Central Composite Orthogonal Design matrix (CCOD). Indeed, it aimed at obtaining a relationship between the specific surface area and the factors. The optimum conditions for ammonium activation process which maximized the specific surface area (SBET ) were found to be 98.28°C, 6.828 h, 4.627 g/g and 0.793 mol L-1 respectively for temperature, contact time, liquid-to-solid mass ratio and ammonium chloride concentration. Under these optimum conditions a specific surface area of activated bentonite of 89.9 m² g-1 was predicted. The experimental value obtained under optimum conditions (87.545 m² g-1) was in good agreement with the predicted value. The second order polynomial model developed was satisfactory in fitting the experimental results. The treatment of Tunisian bentonite with ammonium chloride solution produces an increase in the specific surface area from 47.3 to 87.545 m² g-1 corresponding to an 85% increase.
NaturalLanguageKeyword :
Activated bentonite , response surface methodology , ANOVA , optimization
