Applications of waste date stones as a source of versatile activated carbons

Date pits or stones are becoming an increasingly available renewable biomass resource. Activated carbons for removal of pollutants from both the liquid and gas phase present a potential value-added use of such waste material. Date stones have a high elemental carbon content in the range of 42%– 47% and accordingly the yield of activated carbon is still attractive after physical or chemical activation. The limited number of studies, reporting the conversion of date stones to various types of activated carbons, demonstrates that these carbons can remove phenolic organic compounds, dye-stuffs, heavy metal ions, and various gases. This article reviews the research undertaken on the production and application of date stone derived activated carbons in terms of activation conditions and adsorption capacities for different pollutants. In certain studies, significantly high adsorption capacities are reported indicating the future prospects for these carbons are highly attractive.