Hazard quotient, microbial diversity, and plant composition of spent crude oil-polluted soil

• Published in: Beni-Suef University journal of basic and applied sciences 2020-07, Vol.9 (1), p.1-9, Article 26
• Main Authors: Ikhajiagbe, Beckley, Ogwu, Matthew Chidozie
• Format: Article
• Language: English
• Subjects: Bacteria; Bakeries; Biodiversity; Cadmium; Chromium; Composition; Crude oil; Electric generators; Electric power; Engines; Flowers & plants; Hazard quotient; Heavy metals; Hydrocarbons; Laboratories; Local government; Manganese; Medicine; Medicine & Public Health; Microbial diversity; Microorganisms; Oil pollution; Oil spills; Power plants; Quotients; Soil contamination; Soil mechanics; Soil microorganisms; Soil pollution; Soil remediation; Soils; Species composition; Spent crude oil; Workshops
• ISSN: 2314-8543; 2314-8535; 2314-8543
• DOI: 10.1186/s43088-020-00052-0

Background The present work assesses the concentration of some heavy metal, plant species composition, and microbial diversity of spent crude oil-polluted soil from electric generator plant house, auto mechanic workshop, bakery, and auto spare part shops in four local governments areas (Egor, Ikpoba-Okha, Oredo, and Ovia North) in Edo State, Southern Nigeria. Results Hazard quotient (HQ) of heavy metals varied in all the spent crude oil-polluted soil evaluated in the study. The HQ of heavy metals from auto mechanic workshop had the highest values for Cr (2.19), Mn (0.0965), Zn (4.1108), Fe (9.32015), and Cd (0.0155). The most frequent bacterial and fungal species found in all 16 sites were Bacillus subtilis (93.75%) and Aspergillus niger (100.0%) respectively. Auto spare part shops in Oredo had a bacterial count of 1.0 × 10 5  CFU/g while the bacteria count around power generator plants in Egor had a bacteria count of 1.71 × 10 5  CFU/g. Some of the plant species identified around all the sites include Acanthospermum hispidum , Alternanthera repens , Axonopus compressus , Cyperus esculentus , Eleusine indica , Paspalum scrobiculatum , and Tridax procumbens. Conclusion Spent crude oil pollution of the soil led to high amounts of heavy metal in the soil. However, the presence of higher plants and variable diversity and richness of microorganisms found in the soil are likely contributing to the remediation of the polluted soil.