REVITALIZING GROUNDWATER AND HYDROCARBON IMPACTED SOIL USING INSITU/EXSITU REMEDIATION TECHNIQUES IN OMKPOBU, RIVERS STATE, NIGERIA

Abstract

With all the numerous spills all across Niger Delta ranging from various sources it become imperative for the remediation of the impacted areas. Remediation is means or a process by which an impacted area contaminated by crude oil is restored. Bioremediation could be view from two perspectives which includes Insitu and Exsitu strategies. Both strategies are primarily aimed at removing the contaminants from soil and ground water. While the Insitu strategy address contamination issues in the subsurface the Exsitu strategy address contamination at the surface. Typical examples of the insitu strategies includes Biosparging, Bioventing while that exsitu includes the deployment of landfarming strategies and Biopiling. This research deployed both insitu and exsitu remediation strategy. Specifically, Landfarming as an exsitu remediation techniques was used to address the soil component of the research work. While biosparging remediation strategy was deployed to address contamination within the groundwater. Biosparging and land farming techniques have shown that remediation, especially in terms of groundwater, can be done faster when there are used together. The Exhumed impacted soil was made to undergo steps associated with landfarming techniques. Contaminated soil were exhumed and spread over a prepared bed area for aeration or oxygenation. The spread soil was frequently tilled before there were used to construct windrows to aid the aeration process. The total petroleum hydrocarbons of land farmed soil were drastically reduced before they were returned. These is in line with the view of International Centre for Soil and Contaminated Sites (2006) that ‘’Effective remediation through landfarming will increase microbial activities that will eventually address contamination on soil. Similarly, the impacted ground water also felt the impact of this action and with addition of the sparging operations there were also reduction in the Total Petroleum Hydrocarbon level in the groundwater over the period of the project. The operations of biosparging do not only influence the reduction of Total Petroleum Hydrocarbon (TPH) in the groundwater but also other contaminants of concerns such as benzene.