[Contamination characteristics and source analysis of polycyclic aromatic hydrocarbons in multimedium in karst underground river].

In order to understand the contamination characteristics of PAHs in different environmental mediums of karst underground river, the authors chose the Qingshuiquan underground river as the study object. Based on the data of air, groundwater, sediment and soil samples collected during the same period from 2013 to 2014, contrastive analysis was conducted in light of the component spectra, the distribution features and the characteristic ratios as well as the chemical and physical properties of 16 kinds of PAHs. The results showed that 3 kinds of PAHs with 2-3 rings (naphthalenes, phenanthrene and fluoranthene) were dominant in the air and underground river water, which accounted for 71.66% and 54.84% of the total PAHs. And PAHs with 4-6 rings were dominant in the soil and sediment of the underground river, which accounted for 54.26% and 65.06% of the total .PAHs. The distribution of PAHs in environmental mediums along the underground river indicated that the mean concentration PAHs in upstream area was less than that of midstream, and that of midstream was less than that of downstream, because of pollution discharge and absorption. The ratios of specific PAHs indicated that the PAHs sources in upstream rural area mainly came from the combustion of grassy, wood and coal, the PAHs sources in Ganhuai village were mainly originated from petroleum, and the PAHs sources in the outlet of the underground river mainly came from both petroleum and its combustion.