Synthesis and adsorption properties of activated carbons from biomass of Prunus domestica and Jacaranda mimosifolia for the removal of heavy metals and dyes from water

[Display omitted] ► Jacaranda and plum kernels are used in the synthesis of activated carbons. ► A calcium solution extracted from egg shells is used to impregnate these precursors. ► Activated carbons are used for the removal of dye AB25, MB and Pb2+ from water. ► Activated carbons obtained from plum kernels show the best adsorption performance. Activated carbon is the most widely used adsorbent for wastewater treatment and water pollution control. Lignocellulosic precursors obtained from crops and fruits offer several advantages for synthesizing activated carbons due to its wide availability and their interesting physicochemical properties. In particular, biomass of plum kernel and jacaranda are alternative lignocellulosic precursors for activated carbon preparation. This study reports the application of Prunus domestica and Jacaranda mimosifolia biomass for the synthesis of activated carbons to remove commercial dyes (i.e., AB25 and methylene blue) and Pb2+ ions from aqueous solutions. Two different methodologies for the preparation of activated carbons were analyzed, namely, direct carbonization at 800°C and the impregnation of the biomass with a calcium solution extracted from egg shell wastes prior to carbonization. Results indicated that both carbonization and activation processes improved the uptake of lead, acid blue 25 and methylene blue up to 10 times with respect to adsorption results obtained for raw precursors. Characterization of raw precursors and activated carbons by several techniques were used to understand the adsorption results obtained in this study. Overall, activated carbons obtained from plum kernels showed the best performance for the removal of these priority water pollutants. The adsorption capacities of plum kernel adsorbents are higher (up to 100%) than those obtained for adsorbents prepared from jacaranda.