Ecotoxicological assessment of nano-remediated crude oil contaminated soil using Zea mays

The germination of seedlings is hindered in soil due to the excessive presence of petroleum hydrocarbons resulting from crude oil spill. This contamination not only pollutes the environment but also renders it unsuitable for habitation, inhibits animal grazing, and results in the degradation of natural beauty and aesthetic appeal. In this work, the ecotoxicological effect of nanoremediated soil previously contaminated with crude oil was assessed. Petroleum hydrocarbons were eliminated from crude oil contaminated soil through the utilization of nanomaterial adsorbents namely: Multiwalled Carbon Nanotubes (MWCNTs), MWCNTs + IONP (Iron Oxide Nanoparticle), and P.N.C (Polymer Nanocomposite) followed by the cultivation of Zea mays seedling on the nanoremediated soils then observed over a period of seven days. Both the contaminated and treated samples were evaluated for their respective functional groups, structural morphology and elemental compositions using Fourier Transform Infrared (FTIR), Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Fluorescence (ED XRF) techniques. The seedlings were then harvested, and the lengths of their leaves, shoots, and roots were measured and recorded. Results indicated a germination rate of over 70 % achieved for seedlings cultivated in the nanoremediated soils, in contrast to a germination rate of only 40 % for seedlings grown in untreated crude oil contaminated soil. Seedlings from the soil treated with P.N.C exhibited the most favorable growth parameters, with leaf, shoot, and root lengths measuring 7.64, 4.83, and 8.04 cm respectively. In comparison, seedlings germinated in crude oil contaminated soil displayed measurements of 3.4, 2.79, and 5.32 cm for leaf, shoot, and root lengths, respectively. The pH levels of the treated soils were raised from 5.7 to 6.9, 6.3, and 6.7 for MWCNTs only, MWCNTs + IONP, and P.N.C, respectively. This augmentation had a positive impact on the uptake of nutrients through the root hairs. Additionally, it was noted that the presence of MWCNTs did not impede the germination and growth of Zea mays seedlings. This technique exhibits considerable potential for widespread adoption by farmers, oil companies, and environmental agencies as a rapid and effective nano-remediation method.