Effect of Fermented and Non-fermented Vernonia Amygdalina (Bitter Leaf) Extract on Remediation of Crude Oil Contaminated Loamy Sand Soil

This work considered the remediation of hydrocarbon polluted soil using different volume of fermented and unfermented Vernonia amygdalina (bitter leaf) extracts. The NPK (Nitrogen, Phosphorus, and Potassium) value of the non-fermented and fermented Vernonia amygdalina extract, as well as the pretest of the of the particle size distribution/textural class of the soil conditions, were examined. Physicochemical and bacteriological parameters of the treated soil such as Total Petroleum Hydrocarbon (TPH), Total Polycyclic Aromatic Hydrocarbon (TPAH), Total Monocyclic Aromatic Hydrocarbon (TMAH), and Bacteria Count were determined. The study used Microsoft Excel software, paired t-tests and Analysis of Variance (ANOVA) for statistical analyses. The results showed that the Vernonia amygdalina extract, both fermented and non-fermented, had a high NPK (Nitrogen, Phosphorus, and Potassium) values, hence, making both extracts suitable for cleaning up contaminated soil. At the end of the 72-day remediation period, the results similarly demonstrated a considerable reduction in TPH, TPAH, and BTEX (TMAH) in all treatment approaches. Over the course of 72 days, the percentage reductions for TPH, TPAH, and TMAH for fermented and non-fermented extracts were 98.37, 96.94, 94.51, and 98.57, 92.02, 94.51, respectively. The microorganisms in the area had an impact on these degradations as well. Furthermore, the results of the ANOVA (Analysis of Variance) indicated a slight difference at 95% confidence intervals. Therefore, it is advised that the non-fermented and fermented Vernonia amygdalina extracts be utilized on loamy sand soil contaminated with crude oil for its remediation.