Atmospheric Deposition of PAHs in Dashiwei Karst Tiankeng Group in Leye,Guangxi
广西乐业大石围天坑群多环芳烃的干湿沉降

In order to understand atmospheric deposition of polycyclic aromatic hydrocarbons impact on ecological environment of Dashiwei Karst Tiankeng Group in Leye County,Guangxi(National Geological Park), the dry and wet deposition samples around Dashiwei Tiankeng were collected by season for a year, and were analyzed utilizing GC-MS for 16 EPA PAHs. The results showed that PAH depositional fluxes ranged from 132.36-1655.27 ng·(m2·d)-1, with an average value of 855.00 ng·(m2·d)-1. Weight of PAHs which deposited into Dashiwei Tiankeng was 51.98 g·a-1, and the dominant PAH compounds are benzob]fluoranthene, chrysene, benzoa]pryene, benzok]fluoranthene, anthracene, phenanthrene and naphthalene. Spatial distribution of PAHs around Dashiwei Tiankeng was: the east valley entrance>the south valley entrance>the north valley entrance>the west peak; seasonal variability of PAH depositional fluxes was: spring>summer>autumn>winter. Deposition fluxes of PAHs were 4.6 times higher in spring and summer than those in autumn and winter. The dominant PAH compounds were 4-6 rings PAHs in spring and summer, but the dominant PAH compounds were 2-3 rings PAHs in autumn and winter. PAH depositional fluxes in this study area were closely related with precipitation, wind direction, temperature, wind speed and location of pollution sources. PAHs increased in spring and summer in Dashiwei Karst Tiankeng Group, this could be transported by atmospheric movement from higher air temperature and lower elevation areas where industry developed in Guangxi.