Enhancement of Naphthalene Biodegradation by Sulfate Application in Brackish Subsurface Systems
Abstract
Anaerobic biodegradation is the most dominant mechanism in the petroleum hydrocarbon
contaminated subsurface systems. Due to depletion of terminal electron acceptors such
as sulfate, anaerobic degradation of organic contaminants can be restricted. Hence,
engineered sulfate application has been proposed as an effective remediation strategy to
enhance the activities of sulfate reducer bacteria (SRB) in the contaminated subsurface
systems. However, biodegradation process is significantly affected by environmental
conditions and sulfate application in the contaminated saline and brackish coastal regions is
unknown. A series of flow-through reactors (FTRs) representative of dynamic anaerobic
subsurface conditions were conducted using undisturbed soil samples collected from
brackish (semi)-arid coastal environments in Qatar. Dissolved naphthalene as one of the
most dominant petroleum hydrocarbons that can be found in most of the contaminated
sites was injected into FTRs under different salinity conditions. The relevant geochemical
indicators as well as soil adsorption and dissolved phase concentrations were measured.
The results confirmed development of reducing conditions as well as SRB activity
under experimental conditions. Salinity did not restrict bioremediation and dissolved
naphthalene degradation was more stable and enhanced under brackish water conditions
because microbial cultures within the undisturbed soil were adapted to the brackish
water conditions at the field sampling environment. This paper will provide an overview
of the flow-through experiments and key findings.
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- Civil and Environmental Engineering [851 items ]
- Theme 3: Geotechnical, Environmental, and Geo-environmental, Engineering [21 items ]