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Heavy Metals and Hydrocarbon Contamination of Surface water in Azuabie Creek within Bonny Estuary, Nigeria
MOSLEN, M & AIGBERUA, A
Abstract
The aim of this study was to assess some heavy metals (Cr, Ni, Cd, Pb, Zn and Cu) and hydrocarbon
concentrations of Azuabie creek using the Okujagu creek as a control location. Seventy two samples were collected from
four stations (AZ1, AZ2, AZ3 and OK) in six months (July – December 2016). Samples were analyzed using AAS and GC
spectrophotometry while ANOVA and PCA were used for data analysis.The hydrocarbons (THC, 0.3 ± 0.07 – 84.6 ± 28.85
mg/l, TPH,0.07 ± 0.03 - 45.20 ± 13.88 mg/l & PAH, 0.001 ± 0.0003 – 0.384 ± 0.104 mg/l) were generally higher in Azuabie
creek and showed increased concentration over time with significant difference (p<0.001) between locations and also
between months. The increase in hydrocarbon level is due to oil bunkering and other anthropogenic activities in the study
area. The concentration of Cr, Ni, Cd, and Pb generally exceeded WHO and USEPA limits in water while those of Zn and
Cu fell below such regulatory limits. Site discrimination by PCA showed AZ1 & AZ2 as most dissimilar stations traceable
to higher contaminant levels associated with such sites. In conclusion, the variables within Azuabie creek showed higher
contaminant level compared to the control creek. Complete isolation of each site examined indicates dissimilarity in the
water quality with respect to contaminant level within the creek hence regular monitoring is needed to detect water quality
changes.
Keywords
Heavy metals; hydrocarbon; surface water; contamination
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