Distribution characteristics, source analysis and ecological risk of polycyclic aromatic hydrocarbons in surface water of Guoyang Coal Mine Area, Anhui Province

In order to study the spatial distribution, source and ecological risk of polycyclic aromatic hydrocarbons (PAHs) in surface water of Guoyang mining area, gas chromatography-mass spectrometry (GC-MS) was used to detect and analyze the concentration of 16 kinds of priority control PAHs in surface water of the study area. The results showed that the concentration range of ∑PAHs in the surface water of Guoyang mining area was 93.59-1 701.77 ng/L, with an average content of 674.16 ng/L. The concentration range of monomer PAHs was nd-362.44 ng/L. Among monomer PAHs, the proportion of 2-ring, 3-ring and 4-ring PAHs was relatively high, while that of 6-ring PAHs was relatively low. Compared with the surface water in other regions of China, the concentration of PAHs in the surface water of the research area was at a moderate to high level. In terms of spatial distribution, there was a significant difference in the concentration of PAHs in the surface water of the study area. The closer to the mining area, the higher the concentration of PAHs. The molecular diagnostic ratio (MDR), positive matrix factorization (PMF) and principal component analysis (PCA) methods obtained similar source apportionment results. The results showed that PAHs in surface water mainly came from transportation sources, coal combustion sources and petroleum sources. The contribution rates of each pollution source obtained from PCA were 37.32% for coal combustion sources, 35.51% for transportation sources and 13.92% for petroleum sources, respectively. The contribution rates of each pollution source obtained from PMF model were 42.66% for transportation sources, 30.85% for coal combustion sources, and 26.49% for petroleum sources, respectively. The ecological risk assessment results indicate that BaA, BbF and BkF are at a high risk level, while the remaining monomer PAHs are at a moderate risk level. Among the 22 sampling points, only 6 are at the medium ecological risk level, and the rest are at the high ecological risk level. In general, the overall ecological risk of surface water in Guoyang mining area is at the medium to high risk level, which is potentially harmful to organisms, and ecological risk prevention needs to be strengthened.