Study on hydration and Pb2+ adsorption of cement-spent coffee ground biochar composite cementitious material

A biochar was derived from spent coffee ground by phosphoric acid pyrolysis. Cement-spent coffee ground biochar (CGB) composite cementitious material was prepared by replacing cement by CGB with replacements of 20 %, 40 %, and 60 %, respectively. Then both hydration and Pb 2+ adsorption of the composite were studies in this paper. The results mainly show that although hydration of the composite has inevitably been inhibited to a certain extent due to the incorporation of CGB, under a coupling effect of both cement and CGB, the composite has exhibited super excellent adsorption for Pb 2+ . The utilization of spent coffee ground in building materials could not only provide a new approach for its consumption in a large scale, but could also improve adsorption of cement concrete for heavy metals. Finally, value added of both spent coffee ground and cement concrete could be increased, and their application fields could also be expanded.