Accumulation of Heavy Metals in the Seeds of Zea mays L. from Crude Oil Impacted Soils in Kom-Kom, Rivers State, Nigeria

Abstract

This study assessed and modelled the accumulation of heavy metals in the seeds of Zea mays L. (maize) planted in a crude oil impacted soil. A total of thirteen soil samples were randomly collected. Five samples each were obtained from plot A (PA)and plot B (PB); the crude oil impacted plots. Three samples were obtained from plot C (PC); the control plot which was about 200 m away from the spill impacted area. All samples were analysed for Total Petroleum Hydrocarbon (TPH) and Heavy Metals [iron (Fe), lead (Pb), zinc (Zn), chromium (Cr) and vanadium (V)]. Maize was planted on each of the thirteen plots and the seeds upon harvest was analysed for heavy metals (Fe, Pb, Zn, Cr and V). The seed accumulation factors for each heavy metal was modelled using TPH as the independent variable. Aside the Zn regression model with R2 value of 0.399, other models performed well with R2 values of 0.994, 0.942, 0.974 and 0.964 for Fe, Pb, Cr and V respectively. TPH was able to model the seed parameters with relatively high model performance except for Zinc. This suggests that accumulation of some heavy metals in the seed of the Zea mays L. planted is dependent on TPH. These models can be useful in predicting accumulation of heavy metals in the seeds of Maize planted in a crude oil polluted soil.