Thesis Abstract

Abstract
Activated carbon is a widely used adsorbent in various applications due to its high surface area and porosity. In this study, activated carbon was synthesized from corn cob using two different methods chemical activation and microwave activation. The objective was to compare the characteristics and adsorption properties of the activated carbon produced by these two methods. The chemical activation method involved impregnating the corn cob with phosphoric acid as the activating agent, followed by carbonization at high temperatures. The microwave activation method, on the other hand, utilized microwave radiation to heat the corn cob precursor in the presence of an activating agent. The activated carbons obtained from both methods were characterized using various techniques including scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET) surface area analysis, and thermogravimetric analysis (TGA). The results showed that the chemical activation method produced activated carbon with a higher surface area compared to the microwave activation method. The BET surface area of the chemically activated carbon was found to be 1200 m2/g, while the microwave activated carbon had a surface area of 800 m2/g. SEM images revealed differences in the surface morphology of the two activated carbons, with the chemically activated carbon exhibiting a more porous structure. The adsorption capacities of the activated carbons were evaluated by studying the adsorption of methylene blue dye from aqueous solution. The chemical activated carbon exhibited a higher adsorption capacity compared to the microwave activated carbon, attributed to its higher surface area and pore volume. The adsorption isotherms of both activated carbons were analyzed using Langmuir and Freundlich models, with the chemical activated carbon showing better fit to the Langmuir model indicating monolayer adsorption. Overall, this study highlights the influence of synthesis method on the characteristics and adsorption properties of activated carbon derived from corn cob. The findings suggest that the chemical activation method results in activated carbon with superior properties compared to microwave activation, making it a more promising approach for the production of high-quality activated carbon for various applications in water treatment and pollution control.

Thesis Overview

INTRODUCTION

1.1 BACKGROUND OF STUDY

Activated carbon, also widely known as activated charcoal or activated coal is a form of carbon which has been processed to make it extremely porous and thus to have a very large surface area available for adsorption or chemical reactions (Mattson et al., 1971). The word active is sometimes used in place of activated. It is characterized by high degree of micro porosity. A gram of activated carbon can have a surface area in excess of 500 m2. Sufficient activation for useful applications may come solely from the high surface area, though further chemical treatment generally enhances the adsorbing properties of the material. Activated carbon is most commonly derived from charcoal.

Waste biomass is getting increasing attention all over the world for activated carbon development as it is renewable, widely available, cheap and environmentally friendly resource. The common method of development is thermochemical (Kumar et al., 2005). The main concern is the removal of chemical component by adsorption from the liquid or gas phase (Bansal et al.,1988).