Research Goals: To screen a variety of North American tree species for their ability to enhance the degradation of PAHs and for potential use in phytoremediation strategies.

Overview:  Polycyclic aromatic hydrocarbons (PAHs) are a class of persistent organic pollutants often found in the soil and associated with serious health risks to humans. Unlike heavy metals, PAHs are rarely taken up by plants and transported above the ground. However, bacteria and fungi present in the soil are capable of degrading PAHs. Many species of grasses and other plants have been shown to selectively enhance such microbial populations and in those studies planted soil often had higher rates of degradation than did unplanted soil. Root exudates secreted by plants may play a role in altering or stimulating the microbial community and/or affecting the availability of contaminants to microbes.

Progress to Date: Currently soil samples are being collected and spiked with a mixture of PAHs. These samples will then be evaluated to determine the relationship of soil aging and PAH extraction technique to the availability of the contaminant mixture.

Application of Knowledge: Bioremediation of contaminated soil and groundwater, biofilm processes in wastewater treatment, PAH biodegradation.

Future Directions: Characterize the root exudates of different tree species and evaluate the affect exudates have on microbial communities.

Techniques Incorporated: HPLC, ASE.

Keywords:
PAH biodegradation
Biofilm
Bioremediation
Microelectrodes
Confocal microscopy