The studies on characterization of different type of adsorbent such as coconut shell activated carbon, activated carbon from groundnut and activated carbon from corncob has been performed. The characterization of the adsorbents includes estimation of various parameters such as bulk density, BET surface area, SEM, porosity, pH, iodine number and methylene blue number. Surface area of adsorbents was found by BET surface area analyzer. The pore structure of activated carbon was observed through SEM analysis. The porosity and pore volume was estimated using mercury porosimeter. The adsorbent that showed best surface properties was used for adsorption of methylene blue dye. Adsorption capacity of the activated carbon was determined to access its maximum potential for methylene blue removal.
1.1 BACKGROUND OF THE STUDY
The increase in population has boosted the growth of different industries leading to discharge of pollutants into the water bodies. Among those industries textile, food, cosmetic, paper industries lead to discharge of dye that needs immediate attention. Colour in the water results from various organic chemicals that prevent the sunlight to penetrate affecting the aquatic system. Aquatic organisms and plants are affected due to the release of toxic organic chemicals (Gupta, 2012).
Various methods to address this issue has been published by many researchers such as sedimentation with clarification, coagulation and flocculation, chemical oxidation, filtration using membranes, adsorption, biodegradation etc. For example among these adsorption is a well established technology to deal with dye removal. Methylene blue dye has been used in most of the industries and its removal is a matter of great concern. Low cost adsorbents such as coir pith, sawdust, fruit shell, banana pith, pea nut hull, wheat barn etc has been employed (Chandran et al, 2012). However the use of carbon produced form some agricultural residuals as an adsorbent is greatly sorted as a result of its adsorption capacity (Yadav, 2013).
Carbon produced from agricultural residuals such as corncob, ground shell, coconut etc is a form of carbon processed to have small, low-volume pores that increase the surface area available for adsorption or chemical reactions (Vadivelan,2011). The production of carbon from these agricultural residuals is special type of carbonaceous substance. They have highly crystalline form and extensively developed internal pore structure. Due to activation, internal pore network is created which imparts certain surface chemistries (functional groups) inside each particle. Thus carbon gets its unique characteristics leading to high surface area, porosity and greater strength.
The adsorptivity of the adsorbent depends on both the size of the molecule being adsorbed and the pore size of the adsorbent. The organic material which has high carbon content is used as the raw material for the synthesis of the carbon. There are many cheap, easily available sources used for carbon production such as groundnut shell, corncob, coconut shell wheat husk, straw, palm fiber, rubber wood saw dust, and palm fiber etc. carbon is used in the abatement of hazardous contaminants, treatment of municipal and industrial waste water, as catalyst or catalyst support in medicine, and the recovery of valuable metals (Vadivelan and Kumar, 2010).
Thus the aim of this research is to investigate and show comparison of carbon produced from corncob, groundnut shell and coconut shell.
1.2 AIM AND OBJECTIVES OF THE STUDY
This work tends to study the comparison of carbon production from agricultural residuals such as corncob, groundnut shell and coconut shell. Finding the best among them. Therefore, the specific objectives are as follows;
1. To examine the characterization of carbon produced from corncob, groundnut shell and coconut shell
2. Compare the characteristics of the three; corncob, groundnut shell and coconut shell carbon.
3. To find out the best carbon that is produced which is the best over the other two for adsorption process.
1.3 JUSTIFICATION OF THE STUDY
Carbon production from concob, groundnut shell and coconut shell are processed to have small, low-volume pores that increase the surface area available for adsorption or chemical reactions. Carbon can be used in gas purification, decaffeination, gold purification, metal extraction, water purification, medicine, sewage treatment, air filters in gas masks and respirators, filters in compressed air and many other applications. Also, carbon adsorption has numerous applications in removing pollutants from air or water streams both in the field and in industrial processes.
Furthermore, carbon (charcoal) is an allowed substance used by organic farmers in both livestock production and wine making. In livestock production it is used as a pesticide, animal feed additive, processing aid, nonagricultural ingredient and disinfectant. In organic winemaking, carbon is allowed for use as a processing agent to absorb brown color pigments from white grape concentrates.
The project work is centered on activated carbon of agricultural product using corncob, groundnut and coconut shell. The scope of the work also covers adsorption, activated carbon development and characteristics of activated carbon.