Preparation and Characterization of Activated Carbon from Areca Catechu Nuts as an Absorbent for the Removal of Optilan Red and Glimepiride

Abstract

A series of activated carbons have been prepared from Areca catechu nuts of 425 µm by chemical activation with ortho-phosphoric acid (in the ratio of 0.4:1,0.7:1,1:1,1.5:1 and 2:1), potassium hydroxide (in the ratio 1:1) and zinc chloride (in the ratio 1:1) at 400°C in an inert atmosphere of nitrogen using tube furnace. The methylene blue number and iodine number obtained for the activated carbons were in the range of 108 to 405 mg/gm and 690 to 1080 mg/gm respectively, activated carbon impregnated with ortho-phosphoric acid in the ratio 1:1 (AC-1C) having the highest methylene blue number of 405.243 mg/gm and iodine number of 1080.122 mg/gm. The FT-IR comfirmed the presence of functional groups such as ʋOH, ʋC=O, ʋC-O-C, ʋC=C. The SEM images confirmed the porous structure of the activated carbons. The amorphous structure of the activated carbons was ascertained by XRD patterns. The qm values of AC-1C for the adsorption of methylene blue, optilan red and glimepiride were found to be 434.782, 909,090 and 140.845 mg/gm respectively from Langmuir adsorption isotherm. The adsorption kinetics of optilan red and glimepiride on activated carbons were found to follow pseudo-second order kinetics with k2 value of 2.245×10-3 and 3.21×10-4 gm/mg.min. These experimental results indicated that the Areca catechu nuts can be used as precursor materials for the preparation of high surface area nanoporous activated carbon as an adsorbent.