Sustainable conversion of agriculture wastes into activated carbons: energy balance and arsenic removal from water

International audienceThe aims of this study are to investigate the production of activated carbons (AC) from Senegal agricultural wastes such as cashew shells, millet stalks and rice husks and to implement them in adsorption processes devoted to arsenic (V) removal. AC were produced by a direct physical activation with water steam without other chemicals. This production of AC has also led to co-products (gas and bio-oil) which have been characterized in terms of physical, chemical and thermodynamical properties for energy recovery. Considering the arsenic adsorption results and the energy balance for the three studied biomasses, the first results have shown that the millet stalks seem to be more interesting for arsenate removal from natural water and an energy recovery with a GEEelec of 18.9%. Cashew shells, which have shown the best energy recovery (34.3%), are not suitable for arsenate removal. This global approach is original and contributes to a recycling of biowastes with a joint recovery of energy and material