Proximate and Ultimate Analysis of Walnut Shell as a Potential Low Cost Adsorbent using Different Activating Agents (KOH and H2SO4)

Abstract The need to eradicate toxic or unwanted elements present in the environment has given rise to the use of low cost adsorbents. The feasibility of walnut shell as a low cost adsorbent was analyzed via Proximate and Ultimate analysis using two chemically activated agents (KOH and H2SO4). The walnut sample was carbonized at a temperature of 564 ÂșC for one hour and allowed to cool at room temperature for two hours after which the shells were crushed and sieved to various particle sizes. The proximate and ultimate compositions of the samples were determined in accordance with ASTM methods while the physical properties were determined by qualitative and quantitative methods. The results of the physical properties investigated were; pH (7.7 and 6.9), bulk density (573.9 kg/m3 and 542.7 kg/m3), pore density (700.5 kg/m3 and 673.8 kg/m3 porosity (81.93% and 80.54%), density (635 kg/m3 and 612.1 kg/m3), specific surface area (871 m2/g and 819 m2/g) for KOH and H2SO4 activated walnut shells respectively. The proximate and ultimate analysis gave the following results; % fixed carbon (68.39 and 62.23), % moisture content (13.72 and 16.59), % volatile matter (11.40 and 13.51), % ash content (6.49 and 7.69), % Hydrogen (2.91 and 2.69), % Nitrogen (1.87 and 1.83) KOH and H2SO4 activated walnut shells. The percentage Methylene blue removal was found out to be 91.96% and 74.85% for KOH and H2SO4 activated walnut shells. The results obtained showed that activated carbon produced from walnut has an excellent adsorptive capacity while KOH performs better than H2SO4 in processing activated carbon materials.

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Updated: May 12, 2018 — 1:58 am