BIOREMEDIATION OF CRUDE OIL CONTAMINATED SOIL USING SAW-DUST
Abstract
This study evaluated the effectiveness of sawdust in the bioremediation of crude oil-contaminated soil over a period of 45 days. Standard microbiological and physiochemical methods were employed. The baseline analysis of uncontaminated soil revealed total heterotrophic bacterial (THB) and hydrocarbon-utilizing bacterial (HUB) counts of 7.4x105 CFU/g and 6.0x105 CFU/g, respectively. Following contamination, untreated soil (Sample B) exhibited THB and HUB counts of 8.4x104 CFU/g and 7.4x105 CFU/g, respectively. Samples treated with 3% sawdust (Sample C), 5% sawdust (Sample D), and NPK (Sample E) showed substantial increases, with THB counts of 1.5x106, 1.1x106, and 2.6x106 CFU/g, and HUB counts of 1.38x106, 1.0x6, and 2.4x105 CFU/g on day 0. By day 45, HUB counts increased to 3.1x106 CFU/g (Sample C), 2.4 106 CFU/g (Sample D), and 1.3x106 CFU/g (Sample E). Hydrocarbon degradation was significant, with the PAH content of untreated soil reducing from 25280.34 mg/kg to 24780.15 mg/kg. Treated samples showed more pronounced reductions: 7304.06 mg/kg (Sample C), 6864.18 mg/kg (Sample D), and 2138.94 mg/kg (Sample E). Microbial characterization identified 12 genera of THB and 10 genera of HUB, with Bacillus (23.7%), Pseudomonas (20.8%), and Serratia (12.5%) dominating.The study demonstrated the effectiveness of sawdust and NPK in enhancing bacterial activity and hydrocarbon degradation, highlighting their potential as cost-effective bioremediation strategies. Field-scale applications and long-term soil health assessments are recommended for future research.
Full-Text Access Notice
In accordance with the NERD Policy on promoting peer-reviewed publication, public access to the full text of a project, thesis or dissertation is restricted for three years, allowing the author and supervisors sufficient time to pursue peer-reviewed publication.
During this period, researchers with legitimate academic or research purposes may request authorisation directly from the author to enable NERD to release the indexed full texts of the work using the form below.