Speciation of Heavy Metals in Sediment of Agbabu Bitumen deposit area, Nigeria

Speciation of heavy metals Cu, Cd, Pb, Ni, Zn, Mn, Fe, Cr and Hg was carried out on sediment of Agbabu with a sequential extraction procedure in the dry and rainy seasons of year 2008. Hg was not detected in all the fractions in the two seasons. In the dry season, all the metals were mostly abundant in Fraction-5, however, Cr (30%) and Mn (23.73%) had high abundance in Fraction-1, Zn (30.97%) was high in Fraction-III, Cu (45.14%) and Fe (31.67%) were also high in Fraction-4. In the rainy season, Cr (35.82%) was mostly abundant in Fraction-1, Zn (36.71%) was high in Fraction-3, Cu (29.28%) was high in Fraction-4 and the remaining metals were mostly abundant in Fraction-V. From the results of the two seasons, the metals had high abundance in Fraction-5 indicating firstly, low mobility and bioavailability, secondly, low degree of pollution by the metals considered and thirdly, the origin of the metals in the environment was likely to be lithogenic. The average potential mobility was calculated for the metals in the two seasons and the following decreasing order was obtained: Cr>Zn>Cu>Mn>Fe>Cd>Ni>Pb>Hg. @JASEM J. Appl. Sci. Environ. Manage. December, 2010, Vol. 14 (4) 47 - 51