Activated carbon from baobab fruit shells through domestic processes

Abstract

Surface and groundwater pollution is rampant due to poor waste management and runoff. Dry regions of the country also writhe from water scarcity which leaves communities to resort to unsafe water supplies for domestic use. It is estimated that about 90% rural households in Zimbabwe consume untreated water (Hoko, 2005) and that more than 75% of Zimbabwe's population lives under water stressed conditions in most rural areas (Manyanhaire et al., 2009). Commercially produced activated carbon is expensive. The aim of the research was to investigate the production of activated carbon from baobab fruit shells (a cheap raw material) using a method that can be employed at rural homesteads in removing organic pollutants. Two methods of producing activated carbon were also compared i.e. activating before carbonization and activating after carbonization. Activating with salt after carbonization proved to be the efficient (adsorption% 93.2). A contact time of 60 minutes was determined as the maximum time required for adsorption and a pollutant concentration equivalent to 0.3M oxalic acid gave the highest adsorption of 98.9%. The activated carbon from baobab fruit shells follows a Langmuir isotherm which explains the existence of a monolayer and the saturation of adsorption sites on the activated carbon. It was concluded that activated carbon from baobab fruit shells have the potential of removing organic pollutants from water.

Keywords: activated carbon, percentage adsorption, carbonization, adsorption, organic pollutants and fruit shells