Synthesis of Activated Carbon from Cassava Peeling and Its Applications for Removal of Methylene Blue

Abstract

The present work aims to increase the value of cassava peelings by its transformation in activated carbon. The activated carbon was prepared by chemical activation using 40% of phosphoric acid solution as activation agent with an impregnation rate equal to 1.5 g of acid/g of precursor. The carbonization was carried out at 400°C for 90 minutes. Bohem titration and the Lopez-Ramon method were used to determine the chemical characteristics of the prepared activated carbon (ACCP), while surface area of the sample was estimated by methylene blue and iodine index methods. The best kinetic model that describes the adsorption reaction of MB on ACCP activated carbon is the pseudo-second-order model. Adsorption isotherm was also evaluated. Activated carbon (ACCP) has the following characteristics: pH<SUB>PZC</SUB>= 3.9; Iodine index value equal to 914.4 mg/g and methylene blue index value equal to 643.72 mg/l. ACCP has more acid functions (5.95 meq/g) than basic function (1.3 meq/g). The “batch method” was used for pollutant removal and it reveals that the contact time value is equal to 40 minutes. The influence of activated carbon mass on its methylene blue adsorption capacity was studied. The experimental data are in agreement with the Langmuir and Freundlich isotherm models. The maximum adsorption capacity obtained using Langmuir isotherm model was 75.93 mg/g.