[Pollution Characteristics and Identification of Risk Zones of Polycyclic Aromatic Hydrocarbons and Their Derivatives in Sediments and Soils of Chagan Lake].

Sediments and soils are primary reservoirs and potential secondary sources of polycyclic aromatic hydrocarbons （PAHs）. Investigating the pollution characteristics of PAHs and their derivatives in these environments is of significant environmental， health， and ecological relevance. In this study， Chagan Lake， a typical lake in the agricultural region of northeast China， was selected as the research area. Thirteen surface sediment and soil samples were collected in July 2021 to analyze the pollution characteristics， influencing factors， and ecological risks of 19 PAHs and 11 derivatives. The results showed that the contents of 19 PAHs in sediments ranged from 106.7 to 915.0 ng·g^-1， higher values than those in soils， which ranged from 251.7 to 718.1 ng·g^-1. The average contents of parent PAHs （PPAHs）， methylated PAHs （MPAHs）， oxygenated PAHs （OPAHs）， and nitro PAHs （NPAHs） in sediments and soils were 327.6， 57.7， 59.7， and 21.1 ng·g^-1， respectively. The dominant congeners were primarily 3-ring （38%）， 2-ring （91%）， 3-ring （72%） and 2-ring （81%）， PAHs. An examination of derivatives of Nap， Flu， Ant， and BaA revealed that 2-MN and BA-7，12-D were the main derivatives of Nap and BaA， respectively， with contents lower than their parent compounds. In contrast， the contents of derivatives such as 9-FL， 2-NF， AQ， and 2-MAQ were higher than those of their parent compounds Flu and Ant. Quantitative results from the linear mixing model indicated that the sand ratio had a greater influence on the contents of PPAHs and MPAHs than TOC， particularly for 2-3 ring PPAHs， whereas the effect on 4-6 rings was opposite. Ecological risk assessments indicated that the contents of Nap and Phe in sediments and surrounding soils exceeded the threshold for adverse ecological effects， with 28% of the Chagan Lake area classified as a high-risk zone for overlapping Nap and Phe contamination.