Degradation of ciprofloxacin by peroxymonosulfate activation using catalyst derived from spent lithium-ion batteries

The recovery and reuse of anode materials from spent lithium-ion batteries has attracted increasing attention. This study provides a strategy for the high-value utilization of waste anode materials. Two kinds of catalysts containing different graphite C content were prepared by a calcination process using the anode material of spent lithium-ion batteries. The synthesized AM (AM-450/AM-850) catalysts were applied to activate peroxymonosulfate and degrade ciprofloxacin in water. The AM catalysts consist of CuO and graphite C, which can effectively activate peroxymonosulfate. Under optimal conditions (ciprofloxacin = 10 mg/L; catalyst = 0.4 g/L; [peroxymonosulfate] = 1.0 mM), the degradation efficiencies of AM-450 and AM-850 for ciprofloxacin were 90% and 84% separately within 60 min. Both radical pathways (SO4·−, HO· and ·O2−) and non-radical pathways (1O2, surface electron transfer) participated in the degradation of ciprofloxacin in AM-450/PMS and AM-850/PMS systems with a noticeable difference. The surface electron transfer non-radical channel was the main channel for ciprofloxacin degradation in AM-450/PMS, while the radical degradation channel played a crucial role in AM-850/PMS system. This work presented a novel insight into the peroxymonosulfate heterogeneous activation mechanism with the use of spent lithium-ion batteries derived-catalyst.