Determination of physico-chemical soil quality around yorla oil field area in rivers state, Nigeria
Gbode Lekia Yenor, Akhionbare SMO
Post-remediation status of soil around Yorla oilfield in Kpean community of Rivers State was assessed. A total of 4 soil samples were obtained from four different locations at a depth of 0-20cm using soil auger. Results showed the following levels: N, P, K (0.17 0.01)%, (22.83 1.23) mg/kg, and (32.03 1.82)mg/kg respectively; TPH (607.98 432.06) mg/kg, TOM (2.02 0.16)%, TOC (1.16 0.09)%, Temperature (25.60 0.17)0C, Electrical Conductivity (47.93 1.57) μS/cm and pH (5.99 0.20). The mean concentrations of the heavy metals were Cd (0.03 0.01)mg/kg, Pb (0.40 0.16) mg/kg, Cr (6.18 1.43) mg/kg, Zn (2.91 0.01)mg/kg, V (0.90 0.04)mg/kg, Ni (0.07 0.01)mg/kg and As (0.11 0.03)mg/kg. The principal component analysis showed that principal components 1, 2, 3, were highly correlated with Pb, TPH and soil Temperature respectively. The levels of the quality parameters differed significantly between the control and sampling stations A (sig.F = 0.000), B (sig.F= 0.002) and C (sig.F=0.000) at P <0.05. The soil was moderately acidic and had lower TOC values in the oil impacted soil. Result obtained revealed that the concentration of heavy metals were within the recommended limits by Environmental Guidelines And Standards for the Petroleum Industry In Nigeria (EGASPIN). The observation of this study indicated that the remediation carried out at the oil-spill site was poorly executed and it is recommended that proper treatment of the soil should be carried out so that it could be used for the intended purpose by the community.