Highly Efficient Degradation of Carbamazepine by Activating Peroxymonosulfate with Lithium Cobaltite Cathode Powders Recovered from Spent Lithium-Ion Batteries

It is critical to maximize the reuse of spent lithium-ion batteries (LIBs) due to their significant impact on the economy, society, and environment. In this study, lithium cobaltite (LCO) cathode powders, recovered from spent LIBs, were used as a metallic catalyst to activate peroxymonosulfate (PMS) for carbamazepine (CBZ) degradation. Results revealed that the recovered LCO enables a 99.8% removal efficiency of CBZ (2.5 mg L −1 ) within 1 min due to the rapid electron-transfer rate. Furthermore, recovered LCO exhibited good stability and reusability. Besides, the influence of key factors (such as initial pH, PMS, and catalyst dosage), as well as coexisting anions (such as SO 4 2− , H 2 PO 4 − , NO 3 − , Cl − , and HCO 3 − ), on CBZ degradation were examined in detail. The recovered LCO exhibited excellent catalytic activities in PMS activation at a broader pH range (PH=5.0–11.0). Scavenging experiments and electron paramagnetic resonance (EPR) demonstrated that 1 O 2 , SO 4 . - , and ⋅OH were the primary radical species in the reaction process. By using XPS and electrochemical analysis, the mechanism of PMS activation indicated that radical species were generated through the valence change of Co in recovered LCO. 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 recycle of e-wastes to remove emerging pollutants.