Effect of organic supplement on the poly aromatic hydrocarbon content of a crude oil polluted soil

Le résumé fourni par la source

Background/Aim: One of the many catastrophes produced by mankind throughout history is the environmental deterioration that results from oil spills during extraction, processing, transportation, and corrosion of pipelines or damage. The aim of the study was to remediate crude oil polluted soil through bio stimulation using soybean waste and pigeon droppings. Materials and Methods: Soil samples were obtained from the Rivers State University Demonstration farmland, Port Harcourt, Rivers State. The soil was contaminated evenly with crude oil, thereafter, nutrients were applied. Soil was assayed before and after contamination while physicochemical parameters and Polycyclic Aromatic Hydrocarbon were monitored throughout the experimental period. Bioremediation monitoring was for 56 days, analyses were carried out at 14 days interval. Five (5) experimental setups were employed, and they include Uncontaminated Soil, contaminated Soil, contaminated Soil + Soybean Waste, contaminated Soil + Pigeon Droppings and contaminated Soil + Soybean Waste + Pigeon Droppings. Results: The microbiological analysis revealed that total heterotrophic bacterial count ranged from 4.77±0.47×106 to 5.2±2.80×108 CFU/g, Fungal counts, 5.1±1.11×103 SFU/g to 4.3±0.96×104, Hydrocarbon Utilizing Bacterial counts, 3.9±0.59×103 CFU/g to 3.4±0.10×104, Hydrocarbon Utilizing Fungal counts 3.0±0.53×103 to 2.8±0.59×104 (SFU/g). The bacterial genera identified were Serratia, Bacillus, Chryseobacterium, Aeromonas, Pseudomonas, Micrococcus and Staphylococcus species while the fungal genera were Aspergillus, Penicillium, Trichoderma, Candida, Trichophyton, Alternaria, Colletotrichum and Rhizopus species. The resu lts of the physicochemical parameters observed on day 56 showed that Total Organic Carbon was between 0.80% and 2.08% and the Soil Organic Matter ranged from 2.456 to 3.654%. Total Hydrocarbon Content ranged from 145.33 to 14576.56 mg/kg. The amount of % Bioremediation efficiency at the end of the monitoring (56 days) in the different treatments were as follows: CS+SBW+PD 81.94% > CS+SBW 80.58% > CS+PD 75.53% > CNTRL -VE 53.08%. Conclusion: The findings of the study indicate that pigeon droppings and soybean waste are suitable agents for increased bioremediation because of their high nutritional content. It also showed that a mixture of both bio stimulating agents improved the environment, hence, flourishing of biological activities and it has been demonstrated to be a cost-efficient, environmentally benign and long-lasting method of cleaning up organic contaminants from contaminated soils.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.