Modeling and optimization of process parameters in
elucidating the adsorption mechanism of Gallic acid on
activated carbon prepared from date stones
Authors
Abdelmadjid Chedri Mammar, Lotfi Mouni, Jean-Claude Bollinger, Lazhar Belkhiri, Abdelkrim Bouzaza, Aymene Amine Assadi, Hayet Belkacemi
Publication date
2019/10/20
Journal
Separation Science and Technology
Pages
1-13
Publisher
Taylor & Francis
Description
We make use of chemical activation with phosphoric acid to prepare an activated carbon from date stones (DSAC). After characterization for surface area and pore volume, it was tested as an adsorbent for gallic acid (GA) removal from aqueous solutions: Operating variables including contact time (410 min), adsorbent dosage (0.1 g in 150 mL), GA concentration (10 mg/L) and solution pH (4.5) were optimized using the Box-Behnken design (BBD) under response surface methodology (RSM) approach. Adsorption of GA onto DSAC may be described by the pseudo-second-order kinetics model equation suggesting that the process is chemisorption. The equilibrium data fitted the Langmuir isotherm model with a maximum capacity of 156 mg/g (25°C, pH 4.5). The GA adsorption process was found to be exothermic, while ΔG° was negative implying that the reaction is spontaneous.