Effect of Enhanced Natural Attenuation Remediation on Chronically Oil-impacted Soil in some Communities of Ogoniland, Rivers State, Nigeria

Abstract

Frequent oilspills in the Niger Delta regions have created ecological problems needing solutions. This study therefore investigated the effect of enhanced Natural Attenuation Remediation (ENA) on chronically oil-impacted soil in some communities of Ogoniland, Rivers State, Nigeria. Total petroleum hydrocarbons (THCs) migration was measured at 0.5m soil depth intervals and relevant edaphic variables measured before and after an ENA remediation procedure at 6 sampling locations (OLs).THC contaminants were as high as 40,645.00mg/kg on the surface at OL 1, and undetectable at OL control. Mean concentrations of THC (Sig.value=0.018), C/N ratios (Sig.value=0.050), SO42- ions (Sig.value=0.000) and sand compositions (Sig.value=0.040) differed markedly (p<0.05) across the OLs before remediation, while concentrations of pH (Sig.tvalue=0.048), EC and K+ ions (Sig.tvalue=0.000 each), Na+ ions (Sig.tvalue=0.006), Mg2+ ions (Sig.tvalue=0.024), and clay composition (Sig.tvalue=0.020) differed (p<0.05) after remediation. Results indicate effectiveness of the cost-effective ENA technique in the restoration of soil of a Niger Delta area.

Keywords

• Natural attenuation;
• Oilspills;
• Niger Delta;
• Soil remediation;
• Petroleum hydrocarbons