Browsing by Author "Ikeanumba, Michael Okwudiri"

Now showing 1 - 1 of 1
  • Thumbnail Image
    ItemOpen Access
    Bioremediation of crude oil and heavy metals polluted soil with constructed wetland system
    (Federal University of Technology, Owerri, 2024-11) Ikeanumba, Michael Okwudiri
    The preliminary part of this study was carried out to determine the tolerance limit of eight (8) eight native plant species in soil polluted with crude oil (3%, 7%, and 10% concentrations) and fixed levels of heavy metals (Zn: 39.4 mg/L, Ni: 10.2 mg/L, Cu: 29.4 mg/L, Pb: 11.2 mg/L). The selected plants—Brachiaria distachyoides Stapf, Paspalum conjugatum P.J. Bergius, Cyperus dichrostachyus Hochst. ex A. Rich., Kalanchoe pinnata (Lam.) Pers., Panicum maximum Jacq., Mimosa pudica L., Mariscus ligularis L., and Mariscus rotundus—were sourced from crude oilimpacted sites.Results showed that Paspalum conjugatum P.J. Bergiusgave the best result, thriving in 10% crude oil and heavy metal-contaminated soil for five months followed byMariscus ligularis L. and Brachiaria distachyoides Stapfwhich survived for 30 days under the same conditions. Other species were only able to tolerate 7% crude oil heavy metals. Toxicology studies of amendments revealed that a 1% native soap solution provided optimal growth stimulation for hydrocarbon-utilizing microorganisms (bacteria and fungi), followed by 1% poultry manure and a 1% combination of both. This was followed by 10%, while higher amendment concentrations of 30% significantly inhibited microbial growth.The study shows the effectiveness of hybrid constructed wetlands for the remediation of soil and water polluted with crude oil and heavy metals. Microbial analysis identified Pseudomonas xiamenensis, Acinetobacter baumannii, Alcaligenes cloacae, Enterobacter cloacae, Pantoea dispersa, Lysinibacillus fusiformis, and Kocuria palustris as hydrocarbon-degrading bacterial species in the soil. Among these, Pseudomonas xiamenensis was the most prolific biosurfactant producer, while the others showed moderate production levels.These findings provide valuable insights into the development of sustainable strategies for bioremediation of crude oil and heavy metal-polluted soils.