Engineered biochar derived from eggshell-treated biomass for removal of aqueous lead

Engineered biochars were prepared by slow pyrolysis of three types of biomass pretreated with eggshell waste. The resulting biochars were composite materials with eggshell particles on carbon surface within the pore networks, which were confirmed by various characterization tools. The engineered biochars showed relatively fast adsorption kinetics to Pb2+ aqueous solutions. In addition, adsorption isotherms showed that the Langmuir maximum Pb2+ adsorption capacities of the engineered biochars (103-261 mg/g) were higher than those of the pristine biochars (32.9-56.0 mg/g). The adsorption of Pb2+ onto the biochars were affected by adsorbent dosage, initial solution pH, and ionic strength. Findings from this work indicated that the engineered biochar from eggshell-treated biochar can be used as an effective agent for soil and water remediation and conservation.