Bioremediation of Crude Oil-polluted Soil Using Broiler-Chicken Droppings

Abstract

The impact of poultry droppings in the bioremediation of crude oil-polluted soil was evaluated. Different concentrations of the poultry droppings (10%, 30%, and 50%) were also studied. The physicochemical and microbiological properties of the soil were monitored for a period of 6 months. The poultry droppings had total heterotrophic bacterial and fungal counts of 4.2 × 104cfu/g and 1.8 × 104 cfu/g respectively. The total hydrocarbon utilizers increased progressively from month 2 to month 3, after which a decline from month 4 down occuured. The total heterotrophic microbial counts also increased from month 2 to month 4 followed by a decline from month 5 down. The control showed slight increase in microbial growth. The microbial growth rate increased as the concentration of the poultry droppings increased. Statistical analyses showed a significant difference at (P<0.05), level for the amended options and control. The total hydrocarbon content of the oil-polluted soil decreased from 6609.83 to 2951.37ml/g. Bacillus spp Pseudomonas spp Flavobacterium spp Fusarium spp, Aspergillus spp were isolated. Alkaline pH was observed in the poultry droppings as well as in the amended soils at 50% and lowest at the control. Ecotoxicity assay, measured in terms of germination index was used to evaluate the extent of contaminant removal.. Using seeds of Viciafaba, germination index of 95 % was observed in the 50 % amended option only. The study therefore showed that poultry droppings can serve as a good remediation material in the reclamation of a crude oil-polluted lithosphere.