Trace organic pollutants in sediments from Huaihe River, China: Evaluation of sources and ecological risk

- Residual n-alkanes were mostly from natural sources with low proportion of petrogenic input.
- The concentrations of Σ28PAH and Σ20LAB tend to correlate with two linear models.
- Pyrolytic PAHs in urban and village areas mostly originated petroleum and diesel combustion, respectively.
- The organic pollutants in the sediments of Huaihe River mostly were obtained from local input.

SummaryIn the present study, a combination of multiple molecular markers was used to improve the identification of pollution sources in sediment samples collected from Huaihe River, China. No significant spatial variation of aliphatic hydrocarbons (normal alkanes, n-alkanes) was observed, whereas, relatively high concentrations of 28 polycyclic aromatic hydrocarbons (Σ28PAH) and 20 linear alkylbenzenes (Σ20LAB) in urban sediments and low concentrations of Σ28PAH and Σ20LAB in farm areas were determined. Overall, sediment samples collected from urban areas contained high concentration of Σ20LAB with low concentration of Σ28PAH which mostly originated from pyrolysis, while rural sediments had opposite trends, reflecting the significant input of domestic sewage in urban areas. Residual n-alkanes were mostly from natural sources with relatively low proportion of petrogenic input. For PAHs, the concentrations of diagentic perylene and pyrolytic PAHs from farm areas to urban areas tend to decrease and increase, respectively. Likely origins of pyrolytic PAHs were considered combustion of coal and petroleum related. In the village areas, pyrolytic PAHs were mostly contributed from coal and diesel combustion. Poor domestic wastewater treatment in rural areas caused low ratio of I/E. On the other hand, the results of total toxic benzo[a]pyrene (BaP) equivalent reveal the ecological risk by PAHs was negligible in Huaihe River.