Distribution and potential sources of polycyclic aromatic hydrocarbons in soils around coal-fired power plants in South Africa.
The distribution and potential sources of 15 polycyclic aromatic hydrocarbons (PAHs) in soils in the vicinity of three South African coal-fired power plants were determined by gas chromatography-mass spectrometry. PAH compound ratios such as phenanthrene/phenanthrene + anthracene (Phen/Phen + Anth) were used to provide reliable estimation of emission sources. The total PAH concentration in the soils around three power plants ranged from 9.73 to 61.24 μg g(-1), a range above the Agency for Toxic Substances and Disease Registry levels of 1.0 μg g(-1) for significantly contaminated site. Calculated values of Phen/Phen + Anth ratio were 0.48 ± 0.08, 0.44 ± 0.05, and 0.38 + 0.04 for Matla, Lethabo, and Rooiwal, respectively. Flouranthene/fluoranthene + pyrene (Flan/Flan + Pyr) were found to be 0.49 ± 0.03 for Matla, 0.44 ± 0.05 for Lethabo, and 0.53 ± 0.08 for Rooiwal. Such values indicate a pyrolytic source of PAHs. Higher molecular weight PAHs (five to six rings) were predominant, suggesting coal combustion sources. A good correlation existed between most of the PAHs implying that these compounds were emitted from similar sources. The carcinogenic potency B[a]P equivalent concentration (B[a] Peq) at the three power plants ranged from 3.61 to 25.25 indicating a high carcinogenic burden. The highest (B[a] Peq) was found in samples collected around Matla power station. It can therefore be concluded that the soils were contaminated with PAHs originating from coal-fired power stations.
Chemistry Department, University of South Africa, P. O. Box 392, UNISA, Pretoria, 0003, South Africa.
Olumuyiwa O
OO
Okedeyi
Mathew M
MM
Nindi
Simiso
S
Dube
O R
OR
Awofolu
D003031:Coal; D004784:Environmental Monitoring; D004787:Environmental Pollution / Q000706:statistics & numerical data; D008401:Gas Chromatography-Mass Spectrometry; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis*; D011210:Power Plants; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis*; D013019:South Africa
D003031:Coal; D011084:Polycyclic Aromatic Hydrocarbons; D012987:Soil; D012989:Soil Pollutants