Prospects of in-situ remediation of crude oil contaminated lands in Nigeria

The effects of crude oil exploration in Nigeria have gained both local and international attention, thereby scaling up pressure for remediation. However, there have been no significant successes recorded from previous remediation attempts. Moreover, most related research studies have been ex-situ in pot experiments, greenhouses, or small-scale experimental sites. In lieu of that, this paper discussed the prospects of in-situ remediation of the crude oil contaminated sites on a large scale in Nigeria. In consideration of current Nigeria's status of crude oil contamination and associated limiting factors to remediation, phytoremediation is the most preferable treatment technique recommendable. It is cheap, easy to manage (even by the community), liable to gain public acceptance, and restore livelihood (agriculture and fishing) to the inhabitants. We also outlined practical factors such as site conditions, plant characteristics, agronomic measures, cost estimation, operation and maintenance, the fate of the harvested plants, and regulatory standards. Herbaceous species and trees (i.e. for dendroremediation) which are climatically and environmentally adapted to Nigeria (and other tropical climates) were listed. However, on heavily contaminated soils, phytoremediation can be employed as a final "polishing step" after conventional clean-up and can be combined with other techniques such as vermiremediation so as to enhance efficiency. (C) 2020 The Authors. Published by Elsevier B.V. on behalf of African Institute of Mathematical Sciences / Next Einstein Initiative.