Evaluation of torrefied poplar-biomass as a low-cost sorbent for lead and terbium removal from aqueous solutions and energy co-generation

•Torrefaction allows the building of materials for co-firing/sorption applications.•Torrefaction allows increasing the content of lignin of woody biomass.•The higher heating values increases as a function of the torrefaction severity.•Torrefied poplar biomass is an efficient sorbent for metal recovery from waters.•The high lignin content of the torrefied materials enhances the sorption of terbium.