Characterisation of Activated Carbon Prepared from Groundnut Shell Waste in Katsina State

Agricultural waste biomass presents a cost-effective precursor for the production of activated carbon, an adsorbent material with wide-ranging environmental and industrial applications. In Katsina State, North West Nigeria, groundnut shell waste is generated in substantial quantities as a by-product of groundnut oil processing but remains largely underutilised. This study characterised activated carbon prepared from groundnut shells sourced from a processing facility in Katsina metropolis. The shells were carbonised at 500 degrees Celsius in a muffle furnace, followed by chemical activation using zinc chloride solution at a 1:1 impregnation ratio. The activated product was characterised by determination of iodine number, methylene blue number, surface area, moisture content, ash content, pH of aqueous extract, and bulk density. Scanning electron microscopy images revealed a well-developed porous microstructure, consistent with materials of high adsorptive capacity. The iodine number was 812 mg/g, and the methylene blue number was 246 mg/g, both of which meet or exceed standards for commercially acceptable activated carbon. BET surface area analysis gave a value of 724 m2/g. Ash content was 6.3 percent, and moisture content was 7.1 percent. The aqueous pH was 6.4, suggesting a slightly acidic product suitable for cationic pollutant removal. These results confirm that groundnut shell waste from Katsina State is a viable and locally available precursor for producing activated carbon of acceptable quality for water treatment and related applications. Industrial-scale production is recommended as a value-addition strategy for the agricultural sector.

Keywords: activated carbon, groundnut shell, characterisation, adsorption, Katsina State