Effective peroxymonosulfate activation by lithium cobaltite recovered from spent lithium-ion batteries for enhanced carbamazepine degradation in a wide pH range.

Considering the high cost and complicated recycling process of spent lithium-ion batteries (SLIBs), transforming SLIBs into environment functional materials may be a wise approach. Herein, lithium cobaltite (LCO) cathode powders recovered from SLIBs were used to activate peroxymonosulfate (PMS) for removing carbamazepine (CBZ). The recovered LCO enables a 98.2% removal efficiency of CBZ (2.5 mg/L) within 10 min, which was effective at a broader pH range (pH = 5.0-11.0). The influence of key factors (initial pH, PMS, and catalyst dosage) and coexisting substances (SO, HPO, NO, Cl, HCO, and HA) on CBZ degradation were examined in detail. The primary radical species during the degradation of CBZ were proved to be O, SO, andOH that generated from PMS activation initiated by the valence change of Co in recovered LCO. The recovered LCO displayed excellent reusability with about 80.0% removal of CBZ after six cycles. Homogeneous activation of PMS mainly contributed to CBZ degradation in the first run, but the recovered LCO catalyst dominated the heterogeneous activation of PMS for the degradation of CBZ in the second to sixth run. Finally, the CBZ degradation pathways were presented based on the identified intermediates. This research has offered a new strategy of "treating wastes with wastes" to maximize the recycling of electronic wastes to remove emerging pollutants.