Jornal de Engenharia Química Avançada

Abstrato

Optimal Adsorption Conditions for Tartrazine using Activated Carbon Prepared from Groundnut Shells (Arachis hypoheae): A Comparison between Functionalized and Non-functionalized Carbon Adsorbents

Betga Alex Worldlight*, Ntang Albert Nigho, Daouda kouotou, Mayeukeu Harding Wilfried, Kuisseu Michelle, Juluis Ndi Nsami

The removal of tartrazine from aqueous solution by activated carbon prepared from groundnut shells chemically activated with phosphoric acid, Activated Carbon (AC) and Functionalized Activated Carbon (FAC) has been investigated using kinetics models. Batch isotherm data were analysed with the pseudo-first order, pseudo-second order model as well as the intra-particle diffusion model. For structural elucidation, the materials were characterized using Fourier Transform Infrared (FTIR) and Scanning Electron Microscope (SEM). These analyses revealed that the activated carbons (AC and FAC) were predominantly mesoporous with AC more mesoporous than FAC, both having several oxygen-containing functional groups dispersed on their surface. The reaction was systematically investigated under various experimental conditions such as contact time, adsorbent dose and pH. For the two adsorbents, the quantity adsorbed of 11.57 mg/g and 11.45 mg/g respectively for AC and FAC at contact times of 5 min were obtained. The adsorption data were tested with the Langmuir, Freundlich models. Langmuir model was found to best describe the adsorption of tartrate ions with maximum monolayer adsorption capacities of 17.72 mg/g and 11.01 mg/g for AC and FAC, respectively. Results analysis indicated clearly that the pseudo-second order kinetic rate model best fitted the experimental data and therefore was the adsorption controlling mechanism or both adsorbents. The results show that these AC is a better absorbent than FAC for tartrate ions elimination.