Concentration of heavy metals in a Niger Delta Mangrove Creek, Nigeria

Abstract

The concentration of some heavy metals, Ca, Mg, Fe, Zn, Pb, Cd, Cr, Ni, Hg, and total hydrocarbon content (THC) were assessed in the surface waters of a Niger Delta mangrove creek (Buguma Creek). Samples were collected between November 2004 and October 2006 from five stations. The minimum and maximum concentrations of these heavy metals in the creek were 7.21- 228.5 mg/l for Ca, 51.18-428.3 mg/l for Mg, 0.01-6.78 mg/l for Fe, 0.010-0.43 mg/l for Zn, 0.01-0.61 for Pb, 0.01-0.11 for Cd, 0.01-1.49 mg/l for Cr, 0.01-2.73 mg/l for Ni, while Hg and the total hydrocarbon content was approximately 0.01 mg/l throughout the study period. The rank profile of metals according to their mean values was Mg > Ca > Fe > Zn > Ni > Cr > Pb > Cd > Hg in the study stations. There was no statistically significant difference (P > 0.05) in the concentration of heavy metals at the study stations. The EDTA hardness depicts hard water condition. The extremely low levels of the toxic heavy metals, Ni, Cr, Pb, Cd, and Hg, and total hydrocarbon content (THC) of <1 mg/l indicate that the water was not polluted. INTRODUCTION