Application of biochar for the removal of actinides and lanthanides from aqueous solutions

Abstract

Lanthanide and actinide (mainly from nuclear waste) removal and recovery from aqueous media have recently gained significant attention due to severe health issues related to chronic exposure. These elements tend to be expensive to recover and reuse. Critical waste management is needed for both safe waste disposal and recycling of these elements. Among the different removal techniques, adsorption with biochars and engineered biochars stands out because of its simplicity, cost-effectiveness, and environmentally friendly approach. In this chapter, we have compiled information on biochar-based adsorbents used for lanthanide and actinide removal, with a focus on the experimental conditions typically used in studies, including pH, adsorbent dosage, ionic strength, competition with other ions, and contact time. A summary of sorption kinetics, isotherm, and thermodynamics, and regeneration studies and an overview of the sorption mechanisms are also presented. Ultimately, this chapter aims to provide insight into the significant factors that can affect lanthanide and actinide removal and recovery with biochar and engineered biochars and highlight knowledge gaps and priority areas for future research.