Abstract: To analyze the pollution characteristics of mercury in particulate matters with different sizes, TSP, PM₁₀, and PM_2.5 samples were collected around a coal-fired power plant in Guizhou Province in spring of 2017. Concentrations of mercury in these samples were measured by a cold atomic fluorescence mercury analyzer. The results showed that the volume concentrations of TSP, PM₁₀, and PM_2.5 were 83.7-162, 65.2-130 and 43.6-87.1 μg·m^-3, which exceeded the limit level by 0, 5.63%, and 25.7%, respectively. he volume concentrations of mercury (Cv_(Hg)) in TSP, PM₁₀, and PM_2.5 were 68.5-102, 58.9-84.9, and 51.4-80.9 pg·m^-3 and the mass concentrations of mercury (Cm_(Hg)) were 571-810, 627-913, and 693-1083 ng·g^-1, respectively. Spatially, the concentrations of mercury in the samples collected at upwind direction were much lower than that at the downwind direction. Mercury concentration in the samples at dominant wind direction was generally higher than that at the non-dominant wind direction. Therefore, the local wind direction and sampling site influenced mercury concentration. The ratios of mercury in PM_2.5 to that in PM₁₀ were 67.5%-95.2% and the ratio between PM₁₀ to TSP were 83.1%-98.8%, which were higher than those of particle mass concentrations, indicating that mercury was mainly enriched in fine particles.

Key words: assimilates accumulation and distribution., ¹³C, organic carbon, photosynthetic characteristics, organic fertilizer