A review of technologies and sorbent materials for multi-pollutant gas removal

Industrial flue gases contain multiple pollutants such as SO₂, NOₓ, mercury, particulate matter, and volatile organic compounds, each posing environmental and health risks. Traditional emission control systems treat these pollutants individually, often resulting in high costs, operational complexity, and large equipment footprints. This review presents an overview of the major flue gas pollutants and summarizes recent advances in multi-pollutant control technologies and sorbent materials. It focuses on regulated gas-phase air pollutants, with CO₂ mentioned only where sorbent chemistry overlaps. Both conventional and emerging technologies are examined, including wet and dry scrubbing systems, integrated treatment units, catalytic processes, and novel adsorption techniques. Sorbent categories such as calcium-based, carbon-based, catalytic, zeolites, MOFs, and nanomaterials, are discussed in terms of pollutant removal efficiency, regeneration, and performance limitations. Unlike previous reviews that focus on single technology routes or single material families, this review compares technologies and sorbents by pollutant combination, operating temperature, integration compatibility, and evidence from laboratory to industrial scale. This review aims to improve current practices and offering guidance to future development of cost-effective, integrated systems for simultaneous pollutant capture in industrial applications.