Remediative Capacity of Crude Oil-polluted Soil After Exposure to Poultry Manure and Phosphate Minerals

Abstract

This study investigated the impact of two soil amendments (poultry manure and phosphate rock minerals) on the intrinsic remediation capacity of a crude oil-contaminated soil. Well drained top soil (0-10 cm) was polluted with crude oil at the rate of 0.02mL/g of soil and amended with phosphate rock (PR) and poultry manure in three batches at 20 g, 30 g, 40 g and 50 g per 500 g of soil respectively in plastic bowls. Soil samples were collected from plastic bowls for physicochemical, microbiological, biodegradability and total hydrocarbon contents analyses. Results revealed improvement in physicochemical parameters in pH, total nitrogen and phosphorus of 7.00-7.50, 0.12-0.22 %, and 13.20- 65.42 mg/100 g after remediation against 4.30, 0.02 % and 6.05 mg/100 g recorded in day zero respectively. Bacillus subtilis (2.01), Pseudomonas aeruginosa (1.94), Mucor mucedo (2.47) and Penicillium notatum (2.43) had high biodegradation potential (NTU). The remediation efficiency of total hydrocarbon content after remediation was enhanced by two factors; increased concentrations of amendments of 50 g of poultry manure (4.62 mg/100 g; 66.45 %) and phosphate rock (0.33 mg/100 g; 97.60 %); And by application of combined amendments of both poultry manure and phosphate rock (0.19 mg/100 g; 98.62 %) compared to control (8.46mg/100 g; 38.56 %). Poultry manure and phosphate rock amendments enhance bioremediation efficiency in clean-up of crude oil polluted site and obviously a contamination free environment is a healthy and safe environment for all.

Keywords: Bioremediation, Poultry manure, Phosphate mineral, Hydrocarbon content