Phytoremediation of fuel oil and lead co-contaminated soil by Chromolaena odorata in association with Micrococcus luteus

ABSTRACT

Phytoremediation is widely promoted as a cost-effective technology for treating heavy metal and total petroleum hydrocarbon (TPH) co-contaminated soil. This study investigated the concurrent removal of TPHs and Pb in co-contaminated soil (27,000 mg kg⁻¹ TPHs, 780 mg kg⁻¹ Pb) by growing Siam weed (Chromolaena odorata) in a pot experiment for 90 days. There were four treatments: co-contaminated soil; co-contaminated soil with C. odorata only; co-contaminated soil with C. odorata and Micrococcus luteus inoculum; and co-contaminated soil with M. luteus only. C. odorata survived and grew well in the co-contaminated soil. C. odorata with M. luteus showed the highest Pb accumulation (513.7 mg kg⁻¹) and uptake (7.7 mg plant⁻¹), and the highest reduction percentage of TPHs (52.2%). The higher TPH degradation in vegetated soils indicated the interaction between the rhizosphere microorganisms and plants. The results suggested that C. odorata together with M. luteus and other rhizosphere microorganisms is a promising candidate for the removal of Pb and TPHs in co-contaminated soils.

KEYWORDS:

• Chromolaena odorata
• enhanced phytoextraction
• enhanced rhizodegradation
• Micrococcus luteus
• Pb
• petroleum remediation

Acknowledgment

The authors are grateful to Associate Professor Philip Round for assistance with editing the manuscript.

Funding

This work received a financial support through the Petroleum Authority of Thailand Public Company Limited, Bangkok, Thailand. This research work was supported by grants from the Center of Excellence on Environmental Health and Toxicology (EHT), Thailand.