Adsorption of 2,4-dinitrophenol on Activated Carbon Prepared from Cotton Cakes: Non-linear Isotherm Modeling

In this research, cotton cake has been investigated as a cheap and available precursor used for the production of novel carbon using phosphoric acid and potassium hydroxide as chemical activating agents with 2:1; 1:1, impregnation ratio at various concentrations of 0.5M; 1M; 1.5M using the batch adsorption mode to 2,4-dinitrophenol. Carbonization was performed at 450oC for one hour and allowed to cool. The KOH activated carbon has exhibited high Iodine number values ranging between 447 and 590 mg/g. Thus, KOH was the activating agent in our study and the best ratio was used for the continuation of our work. The activated carbon was characterized by Fourier transform-infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and proximate analysis (pHZCP, pH, bulk density, moisture content, ash content, volatile mater, fix carbon content and matter soluble in water).The experimental isotherms were analyzed using two, three and four parameter sorption isotherm models. Three errors analysis methods were used to evaluate the experimental data: correlation coefficient (R2), Chi-square (χ2), Average Relative Error (ARE), Sum of Absolute Errors (EABS) and Root mean square error (RMSE) values were tested to find the best fitting isotherm. According to chi-square test (X²), it appears that the Freundlich (two parameters), Hill (three parameters) and Marczweski-Jaroniec (four parameters) models describe better the adsorption data.