Upcycling of spent battery acid-leaching residue and waste plastic into magnetic-recyclable industrial flue gas DeHg sorbent

The extensive application of batteries has precipitated a notable generation of solid waste, necessitating urgent management to avert environmental concerns. Concurrently, flue gas mercury pollution poses a growing threat to human health and ecosystems. This work presents a novel one-step co-pyrolysis method, which directly upgrades spent battery acid-leaching residue (SBAR) and polyphenylene sulfide (PPS) plastic into magnetic-recyclable sorbents for efficient Hg⁰ removal. The conversion of CaSO₄ and FeSO₄ in SBAR to CaS and Fe₇S₈, facilitated by PPS, is crucial for Hg⁰ capture. Optimization of the pyrolysis parameters discloses that SBAR-PPS_op, prepared at 700 °C with a PPS doping ratio of 0.33, manifests outstanding Hg⁰ removal performance (η = 100 % in pure N₂), exceptional anti-interference capacity (η > 98 % in simulated flue gas), and excellent recyclability (η > 95 % after 10 cycles). Its remarkable regenerability stems from the adaptive alteration of Hg adsorption configurations on CaS. During successive reuses, the reduction of active S sites induces a shift from Hg-S-bridge to Hg-S-top bonding, mitigating the performance decline of recycled sorbents. This attempt provides an illuminating avenue for the integrated disposal and management of SBAR and waste PPS plastics.