Assessment of the phytoremediation capacity of Vetiveria Zizanioides for the remediation of crude oil contaminated soils

Abstract

This study was conducted to evaluate the phytoremediation capacity of Vetiveria Zizanioides in crude oil-contaminated soils in Imiringi, Bayelsa State. 2000g sample of soil was collected, homogenised and divided into six equal parts A, B, C, D, E, and F, respectively. Sample B, D and F were artificially contaminated with 200 cm³ of crude oil each and homogenised again. Samples A, C, and E served as control over B, D and F, respectively. This was followed by series of tests. First, Agaricus bisporus was added to Sample C to make it a Myco-rich environment. A. bisporus was also added to sample D. A. bisporus thrived on C for 4 days while it was observed to almost immediately decompose in D. Furthermore, grown Pistia stratiotes (Linn.) was transplanted on both Samples C and D at the same time. P. stratiotes (Linn.) on Sample C blossoms while within very few minutes of transplanting, P. stratiotes (Linn.) in Sample D lost its colouration and died within two (2) hours. Moreso, both the V. zizanioides and Leptochloa caerulescence (Steud.) were grown and transplanted on samples E and F. Both grew on sample E whereas L. caerulescence (Steud.) could not even survive a day on sample F. The death of the Leptochloa caerulescence (Steud.) could be attributed to the crude oil contamination. The results of the current study shows that V. Zizanioides is promising for the remediation of petroleum hydrocarbon contaminated soils. However, further work is needed to evaluate its potency for one to two vegetation periods; and genuinely crude oil-contaminated soils.