Author : TCHUIFON TCHUIFON Donald Raoul, ANAGHO Solomon Gabche, NCHE George Ndifor-A. and KETCHA Joseph Mbadcam

Activated carbons prepared by chemical activation of rice and coffee husks with phosphoric acid were used to study the adsorption of salicylic and sulfosalicylic acids. The characterization of the prepared activated carbons showed that the pH at zero charge was between 2.3 and 3.45; the bulk density was around 0.800 g/cm3 and the iodine number was between 476 and 590 mg/g. The adsorption process took place in two stages, and the adsorbents had a good affinity for the two acids. The adsorption capacity was found to increase with increasing molar mass of the adsorbates, and the best pH for adsorption of 2 was below the pH of zero charge. The kinetic and equilibrium examination of the process showed the adsorption to be chemical in nature, exothermic and occurred only over a monolayer.

Keywords: adsorption, activated carbon, phenolic compounds, rice and coffee husks.

Article published in International Journal of Current Engineering and Technology, Vol.5, No.3 (June-2015)