Converting spent battery anode waste into a porous biocomposite with high Pb(II) ion capture capacity from solution

Taking advantage of the low-cost carbon and manganese sources of the spent battery anode waste (SB), porous biocomposites were synthesized by co-pyrolyzing of SB with sawdust. Synthesis method was optimized, and potential biocomposite application in the aspect of Pb(II) removal in the wastewater was investigated and the related possible mechanism of Pb(II) removal was discussed. Composite derived at 750 °C with 10% SB loading amount had high Pb(II) adsorption capacity with negligible influence of ion strength. The maximum Pb(II) adsorption capacity was around 183.82 mg/g at 298 K and pH 4, and the increase of the temperature favored Pb(II) adsorption. Pb(II) adsorption behavior fitted the intraparticle diffusion model and Redlich-Pearson model. Pb(II) removal was governed by precipitation, complexation and Cπ−Pb(II) bond interaction combined processes. Co-pyrolysis of sawdust with SB not only explores an approach for the SB utilization but also provides an excellent biocomposite for solution Pb(II) ion adsorptive removal.