Evaluation of the use of legumes for biodegradation of petroleum hydrocarbons in soil

Abstract

The aim of this research was to evaluate the potential of six legumes: Medicago sativa L., Glycine max, Arachis hypogea, Lablab purpureus, Pheseolus vulgaris and Cajanus cajan to restore within a short period of time soil contaminated with 3% crude oil. The legumes in five replications were grown in crude oil-contaminated and crude oil-uncontaminated soil in a completely randomized design. Plants were assessed for seedling emergence, plant height and leaf number. GC-MS was used to analyze the residual crude oil from the rhizosphere of the legumes. Plant growth parameters were reduced significantly (P \ 0.05) for legumes in contaminated soil compared to their controls. In the 4th week after planting (WAP), shoot height increased across the species up to the 8th WAP. However, in the 12 WAP no significant increase in the shoot of all species was observed. Two WAP legumes planted in contaminated soil had significantly (P \ 0.05) higher leaf number than these planted in uncontaminated soil with the exception of M. sativa. In the 4th WAP, only A. hypogea and P. vulgaris had increased leaf number, while in the 6th WAP, only L. purpureus had increased leaf number and survived up to the 12th WAP while most of the legumes species died. Chromatographic profiles indicated 100% degradation of the oil fractions in C. cajan and L. purpureus after 90 days. For other legumes however, greater losses of crude oil fractions C 1 -C 10 and C 10 -C 20 were indicated in rhizosphere soil of P. vulgaris and G. max, respectively. The most effective removal (93.66%) of C 21 -C 30 components was observed in G. max-planted soil even though vegetation was not established. The legumes especially C. cajan, L. purpureus and A. hypogea are promising candidates for phytoremediation of petroleum hydrocarbon-impacted soil.

Biosurfactant-Assisted Phytoremediation of Diesel-Contaminated Soil by Three Different Legume Species

“…Legumes could be an excellent option for the phytoremediation of petroleum hydrocarbon-contaminated soil due to their unique properties [16,50,51]. However, the plant's resistance to contamination is the key determinant of its suitability for phytoremediation.…”

“…Legumes have an advantage over non-nitrogen-fixing plants because they can fix nitrogen. This means they do not have to compete with microorganisms and other plants for the limited soil nitrogen reserves in oil-contaminated areas [50]. Moreover, legumes stimulate petroleum-degrading microorganisms in the rhizosphere by providing the necessary nutrients and root exudates into the rhizosphere.…”

Effects of Plant and Soil Amendment on Remediation Performance and Methane Mitigation in Petroleum-Contaminated Soil

“…Plants that promote the decomposition of organic contaminants in soil share common characteristics, including extensive and fibrous roots that form an extended rhizosphere [21]. These plants include many common grasses, maize, and legumes (e.g., soybeans, peas, beans) and have been assessed in many TPHcontaminated soil rhizoremediation studies [22][23][24]. In this study, maize and tall fescue were examined in an indoor pot experiment, and both plant species were found to significantly improve TPH removal rates (Fig.…”

Influence of Bacteria of the Genus Pseudomonas on Leguminous Plants and Their Joint Application for Bioremediation of Oil Contaminated Soils

“…Bioremediation is an effective option for restoring oil-polluted ecosystems using the degradation capabilities of plants and microorganisms. Representatives of the family Fabaceae are often used as phytomeliorants [ 24 , 25 ], since, compared to plants of other families, legumes provide not only the recultivation of polluted soil, but also help restore the balance of nitrogen and carbon [ 26 ]. Most often, various types of alfalfa and clover and their legume-cereal crop mixtures are used to clean the soil from oil [ 27 , 28 ].…”