Abstract:Elemental mercury (Hg0) and chlorinated volatile organic compounds (CVOCs), which are highly toxic, exhibit significant migration and transformation capabilities, making them prone to forming various secondary pollutants in the atmosphere. This poses serious threats to human and environmental health, garnering widespread global attention. Despite numerous studies, controlling mercury and CVOCs in industrial flue gas remains a significant research challenge. Notably, there are few reports on the impact of CVOCs on the low-temperature adsorption of Hg0. This study investigated the low-temperature adsorption performance of various common adsorbents for Hg0, specifically assessing the effect of CVOCs using chlorobenzene as a model compound. We prepared three types of materials: activated carbon and its modified materials, sulfide, and metal oxides, and evaluated their Hg0 adsorption activity at low temperature (80-120 ℃). The adsorption performance was ranked as follows: CuS/AC>CuS>Mn2O3>AC>HCl/AC. Brunauer-Emmet-Teller (BET) analysis indicated no direct relationship between the specific surface area or pore type of the adsorbents and their Hg0 adsorption performance. In contrast, X-ray photoelectron spectroscopy (XPS) results revealed that oxidizing species such as Cu2+, , and Mn3+ in CuS and Mn2O3 served as the primary active sites for the chemisorption of Hg0. After adding chlorobenzene, the adsorption performance of CuS/AC and AC remained unchanged, while the other three materials exhibited inhibited performance, particularly Mn2O3, whose adsorption efficiency decreased by over 50%. Hg0 temperature-programmed desorption (TPD) experiments demonstrated that HgS was the predominant form of mercury in CuS/AC and CuS when only mercury was present in the flue gas. In Mn2O3, HgO was the primary form, accompanied by some physically adsorbed mercury, whereas AC only facilitated physical adsorption of Hg0. In HCl/AC, both HgCl2 and physical adsorbed Hg0 were detected. Following the addition of CVOCs, the main form of mercury in CuS remained HgS, while physical adsorbed mercury appeared in CuS/AC. Additionally, Mn2O3 exhibited a new adsorption component, HgCl2. Kinetic analyses indicated that the adsorption process of Hg0 across different adsorbent materials conformed to a pseudo-first kinetic model (R2>0.99), highlighting the dominant role of external diffusion. The presence of chlorobenzene further enhanced the chemisorption of Hg0 by HCl/AC and Mn2O3. Moreover, the Hg0 adsorption capacities of AC, HCl/AC, CuS, and Mn2O3 decreased significantly in the presence of chlorobenzene, dropping from 842.5, 573.4, 55 505.6, and 3 352.6 μg/g to 730.3, 181.7, 5 504.1, and 434.0 μg/g, respectively. By exploring the effects of CVOCs on the adsorption of Hg0, this study contributes valuable insights for future research on low-temperature co-adsorption methods involving Hg0 and CVOCs. Close-