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Denitrification Coupled Biotreatment of PAHs for Treating Wet SoilsEPA Grant Number: U915984
Title: Denitrification Coupled Biotreatment of PAHs for Treating Wet Soils
Investigators: Miles, Kenyatta
Institution: Howard University
EPA Project Officer: Graham, Karen
Project Period: January 1, 2001 through January 1, 2002
Project Amount: $66,210
RFA: Minority Academic Institutions (MAI) Fellowships for Graduate Environmental Study (2001) RFA Text | Recipients Lists
Research Category: Academic Fellowships , Engineering and Environmental Chemistry , Fellowship - Engineering
The objective of this research project is to improve treatment coefficients for nitrate-driven bioremediation of polycyclic aromatic hydrocarbon (PAH)-contaminated soils in wet conditions.
There is increasing evidence that in the absence of oxygen, microorganisms are capable of oxidizing complex organic carbon contaminants in the subsurface environment by using other electron acceptors such as nitrate. Recent work has shown that under anaerobic conditions, PAHs can be degraded by a consortium of microorganisms. Other recent studies suggest that both the lag time and effectiveness of low-cost treatments on biodegradation of a PAH added to soil are related to the history of the soil's exposure to PAHs. Degradation of heavier PAHs, such as pyrene or benzo-a-pyrene, may be enhanced by systems containing less complex PAHs, such as naphthalene and anthracine. The mechanism for this is believed to be changes in the soil microbial community structure initiated by the presence of more readily degraded PAHs. An ability to quantify these relationships would benefit industry's capabilities in treating low-oxygen, water-saturated systems. In a series of laboratory studies, mesocosm/bioreactor techniques will be used to relate remediation and microbial consortia changes following PAH amendments to soil. Nitrate additions will be varied to assess the impact of denitrification on remediation rates. At least two thermal regimes and two soil moisture regimes will be examined.