Indication and Quantitative Assessment of Polyarene Sources in Soils by Statistical Modeling (Oil and Gas Extraction Area, Volgograd Region)

The polyarene complex of soils was investigated, and PAH sources were assessed quantitatively in soils in the area subjected to heterogeneous technogenic impact near the town of Zhirnovsk, Volgograd oblast. The objects of study were the soils on interfluve areas within the oil and gas field, including soils of agricultural lands, floodplains, urban area, as well as oil-contaminated soils. PAH concentrations vary from 16 to 330000 ng/g; light PAHs, naphthalene and phenanthrene homologues are predominant; heavy PAHs were detected in the amount of 78.5 ng/g mainly in the urban area. The Positive Matrix Factorization (PMF) model was used to indicate and quantify the PAH sources. The following sources of PAHs were identified: emanation, old oil injection, new oil injection, traffic, public gas-pyrogenic, public wood-pyrogenic, and biogeochemical. They determine, respectively, the following associations of PAHs in soils: diphenyl, anthracene-chrysene, chrysene-naphthalene, fluorene-benzo[ghi]perylene, tetraphene-benzo[ghi]perylene, pyrene-anthracene-benzo[a]pyrene, and phenanthrene associations.

Automated summary

The study revealed a wide range of PAH concentrations in soils near Zhirnovsk town subjected to heterogeneous technogenic impact, with predominance of light PAHs and heavy PAHs mainly detected in urban areas.