SOURCE IDENTIFICATION AND ECOTOXICOLOGICAL RISK ASSESSMENT OF POLYCYCLIC AROMATIC HYDROCARBONSIN SEDIMENT FROM KOMADUGU RIVER BASIN, YOBE STATE, NIGERIA Page No: 4355-4365

By: Joseph C Akan, Zakari Mohammed, Abdullahi Idi Mohammedand Lami Jafiya

Keywords: PAHs, sediments, diagnostic ratios, ERM, MACs, Komadugu River

Abstract: Polycyclic aromatic hydrocarbons (PAHs) were determined in sediments from five sampling points designated as S1 to S5 from Komadugu River basin, Yobe State, Nigeria. The concentrations of PAHs in sediment samples ranged from 1.42E-04 to 1.65E-01 mg/kg. Dry season were observed to show the highest concentrations of all the studied PAHs with a total value of 2.72E+00 mg/kg, while the rainy season shows the lowest concentrations with a total value of 1.88E+00 mg/kg. The concentrations of the studied PAHs in the sediment samples were below the maximum allowable concentrations (MACs) of 0.15 to 3.0 mg/kg. Results of the study shows that the ratio of BaA/BaA + Chr were between 0.40 and 0.50 with mean of 0.57, which indicate pyrogenic sources, the Ant/Ant + Phe ratios were between 0.21 and 0.63 indicating fuel combustion sources, while Flua/Flua+Pyr of 0.44 confirmed the combustion of fuel as the main PAH source in the study area. The diagnostic ratios show both fuel combustion and pyrogenic sources of PAH in the study area. The m-ERM-q in the sediments were below 0.1 indicating an 11 percent probability of toxicity and are therefore classified as low priority sites.



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