Effect of Animal Bone Biochar on Total Petroleum Hydrocarbon Reduction and Fertility Restoration in Crude Oil–Contaminated Soil
Ejike Immaculate Ugochi
World Bank Africa Centre of Excellence for Oilfield Chemicals Research, University of Port Harcourt, Choba, PMB 5323, Port Harcourt, Rivers State, Nigeria.
Ogugbue Chimezie Jason
World Bank Africa Centre of Excellence for Oilfield Chemicals Research, University of Port Harcourt, Choba, PMB 5323, Port Harcourt, Rivers State, Nigeria and Department of Microbiology, University of Port Harcourt, Choba, PMB 5323, Port Harcourt, Rivers State, Nigeria.
Onojake Mudiaga C. *
World Bank Africa Centre of Excellence for Oilfield Chemicals Research, University of Port Harcourt, Choba, PMB 5323, Port Harcourt, Rivers State, Nigeria, Petroleum & Environmental Chemistry Research Group, Department of Pure and Industrial Chemistry, University of Port Harcourt, Choba, PMB 5323, Port Harcourt, Rivers State, Nigeria and Institute of Natural Resources, Environment and Sustainable Development (INRES), University of Port Harcourt, Choba, PMB 5323, Port Harcourt, Rivers State, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
Crude oil contamination significantly impairs soil fertility and plant productivity due to hydrocarbon toxicity, reduced microbial function, and nutrient imbalance. This study evaluated the efficacy of cow bone-derived biochar (ABB) in enhancing total petroleum hydrocarbon (TPH) degradation and supporting the recovery of soil productivity in crude oil-polluted soils. A 90-day experiment was conducted using soils artificially contaminated with 5% (w/w) crude oil and amended with 20 g, 60 g, and 100 g of ABB per kilogram of soil. The remediation performance was assessed through TPH degradation analysis and plant bioassays using Phaseolus vulgaris (White bean) as a test crop. Results revealed a significant, dose-dependent reduction in TPH levels across all treatments. By Day 90, the highest ABB amendment (100 g/kg) achieved up to 75% TPH removal, compared to only 28% in the unamended control. Plant growth parameters, including germination rate, shoot and root length, leaf count improved markedly in ABB-treated soils. The enhancements indicated reduced hydrocarbon toxicity and partial restoration of soil fertility. The porous, alkaline nature of ABB likely contributed to contaminant adsorption and pH buffering, creating a more favorable environment for plant establishment. This study demonstrates that animal bone-derived biochar is a cost-effective and sustainable amendment that supports both hydrocarbon remediation and biological recovery in oil-impacted soils. The dual functionality of ABB in promoting contaminant breakdown while enhancing soil productivity presents a viable strategy for ecological restoration.
Keywords: Biochar amendments, bioremediation, petroleum, soil fertility restoration