Potential of Castor Seed (Ricinus communis) for Remediation of Petroleum Products Contaminated Soil in Billiri, Gombe State, Nigeria.

Petroleum products consist of hazardous chemicals such as benzene, toluene, ethylbenzene, xylene, and naphthalene, which can be detrimental to all parts of the ecosystem, especially the land. Hence, the objective of this paper was to evaluate the potential of castor seed (Ricinus communis) for remediation of petroleum products contaminated soil in Billiri, Gombe State, Nigeria using appropriate standard techniques. Tests results showed that the petroleum products significantly altered the physicochemical properties, heavy metals and THC of the soil. The soil porosity decreased from 76.20% to 36.5%; the soil pH decreased from 7.10 to 6.0; the THC increased from 0.268 mg/kg to 878.4 mg/kg while heavy metals content such as copper level increased from 17.20 mg/kg to 53.9 mg/kg; the lead content increased from 10.39 mg/kg to 16.0 mg/kg; while the iron content increased from 31.72 mg/kg to 63.4 mg/kg after the contamination. After the 14 weeks phytoremediation period, Ricinus communis was able to degrade the THC in the soil from 878.4 mg/kg to 254 mg/kg while also showing potential for the degradation of other heavy metals in the soil. [ABSTRACT FROM AUTHOR]