No abstract

This study was performed to elucidate the distribution, concentration trend and possible source of polycyclic aromatic hydrocarbons (PAHs) in surface water and bed sediments of the Hungarian upper section of the Danube River and the Moson Danube branch. A total of 217 samples (water and sediments) were collected from four different sampling sites in the period of 2001-2010 and analysed for the 16 priority US Environmental Protection Agency PAHs. Concentrations of total 16 PAHs (∑PAHs) in water samples ranged from 25 to 1,208 ng/L, which were predominated by two- and three-ring PAHs. The ∑PAH concentrations in sediments ranged from 8.3 to 1,202.5 ng/g dry weight. Four-ring PAHs including fluoranthene and pyrene were the dominant species in sediment samples. A selected number of concentration ratios of specific PAH compounds were calculated to evaluate the possible sources of PAH contamination. The ratios reflected a pattern of pyrogenic input as a major source of PAHs. The levels of PAHs determined were compared with other sections of the Danube and other regions of the world.

The objective of this study was to investigate the concentration level and distribution of polycyclic aromatic hydrocarbons (PAHs) in surface water of the Raba River; the largest Danube tributary in Hungary. A total of 54 water samples were collected in the period of 2008-2011 and analysed for PAHs by gas chromatography-mass spectrometry (GC/MS) method. The total PAH concentrations (sum of the concentrations of 17 individual PAH compounds) ranged from 41 to 437 ng/L with the mean value of 111 ±  69.4 ng/L. Phenanthrene and naphthalene were the dominant species in the surface water. Using TEF approaches on the mean concentration PAH data, benzo[a]pyrene and dibenz[ah]anthracene contributed the highest carcinogenic exposure equivalent. A selected number of concentration ratios of specific PAH compounds were calculated to evaluate the possible sources of PAH contamination. The ratios reflected a pattern of pyrogenic input as a major source of PAHs. The comparison of the total PAH concentrations observed for Raba River with other surface waters of the world confirmed that the Raba River could not be regarded as a contaminated river according to the levels of PAHs.

Polycyclic aromatic hydrocarbons (PAHs) were identified and quantified in surface water and sediments from 9 sites in the Hungarian upper section of the Danube River and its tributaries in autumn 2012. The total PAH concentrations (sum of the concentrations of 17 individual PAH compounds) in water samples ranged from 67 to 96 ng L(-1), which were predominated by two- and three-ring PAHs. The total PAH concentrations in sediments ranged from 35.2 to 288.3 ng g(-1) dw. Four-ring PAHs including fluoranthene and pyrene were the dominant species in sediment samples. The spatial distribution of PAHs in sediments was site-specific. The highest benzo[a]pyrene equivalent concentration was determined at the site located near a hazardous waste incinerator. However, the comparison of the total PAH concentrations determined with other sections of the Danube River and the environmental quality standards revealed that the PAH concentrations are relatively low in the Hungarian upper section. A selected number of concentration ratios of specific PAH compounds reflected a pattern of pyrogenic input as a major source of PAHs.

The aim of this paper is to investigate the concentrations of polycyclic aromatic hydrocarbons (PAHs) in surface water of the Hungarian upper section of the Danube River in the period of 2007-2010. A total of 77 water samples were collected from the sampling sites located at Rajka, Medve and Komárom (1848, 1806 and 1766 river km) under the authority of the Inspectorate for Environment, Nature and Water of the North Transdanubian Region designated by the Hungarian National Monitoring Programme. Sixteen PAHs identified by the US Environmental Protection Agency (USEPA) as priority pollutants were monitored. Concentrations of total 16 PAHs (∑PAHs) ranged from 25 to 357 ng⋅L-1 with the mean value of 98.27 ± 58.48 ng⋅L-1. The low and medium molecular weight PAHs (2-3 and 4 ring) ranged from below method detection limit (<1) to 136 ng⋅L-1 while high molecular weight PAHs (5-6 ring) were present at much lower concentrations (<1-25 ng⋅L-1). The 2-3-ring PAHs contributed to about 64% while 4-6-ring PAHs accounted for 36% of the ∑PAHs. The dominant species are naphthalene and phenanthrene in the surface water. Concentration ratios of specific PAH compounds including anthracene/(anthracene+phenanthrene) and fluoranthene/(fluoranthene+pyrene) were calculated to evaluate the possible sources of PAH contamination. The levels of ∑PAHs determined in our study were compared with other sections of the Danube and other regions of the world.