Low-carbon control of heavy metals in industrial flue gas

Heavy metals emitted from industrial sectors represent a class of recalcitrant atmospheric pollutants with severe ecotoxicological hazards even at trace levels. Their control is complicated by temperature-dependent volatilization, chemical transformation, phase redistribution, and interactions with reactive flue-gas components. This Mini Review examines heavy-metal control from the physicochemical basis of release and speciation to gas-phase regulation, interfacial capture, and removal in conventional air-pollution-control devices. Particular attention is given to low-carbon control strategies, which aim to reduce additional energy and material inputs by lowering energy consumption, implementing co-benefit control, and utilizing flue-gas components, while avoiding placing an excessive burden on downstream treatment processes. Controlled cooling, adsorption, catalytic or chemical speciation conversion, wet absorption, and plasma-assisted activation can effectively regulate heavy-metal fate, but their overall benefit depends on energy demand, reagent consumption, and the stability of the resulting metal-containing residues. Current technologies also face three persistent limitations: high energy and material inputs, secondary release from unstable captured metals, and difficulties in resource recovery from complex residues. Future development should therefore couple efficient removal with lower process burden and a defined final endpoint, directing recoverable streams toward resource recovery and other residues toward durable stabilization. This system-level perspective positions low-carbon heavy-metal control as an important direction for cleaner industrial flue-gas management.