Bioremediation of contaminated sediments
- Rice Univ., Houston, TX (United States)
Contaminants in bottom sediments have historically been considered to have minimal environmental impact because they are buried, sorbed or electrostatically bound to clay particles, or incorporated into humus. Physical and chemical conditions such as alkalinity, pH, and redox of the sediments also play a part in sequestering contaminants. As long as the sediments are undisturbed, the contaminants are considered stabilized and not an immediate environmental problem. Resuspension of bottom sediments makes contaminants more available for dispersal into the marine environment. Events that can cause resuspension include storm surges, construction activity, and dredging. During resuspension, sediment particles move from an anaerobic to aerobic environment, changing their redox characteristics, and allowing the indigenous aerobic bacteria to grow and utilize certain classes of contaminants as energy sources. The contaminants are also more available for use because the mixing energy imparted to the particles during resuspension enhances mass transfer, allowing contaminants to enter the aqueous phase more rapidly. The contaminants targeted in this research are polynuclear aromatic hydrocarbons (PAHs), a class of contaminant commonly found in bottom sediments near highly industrialized areas. PAH sources include fossil fuel combustion and petroleum spills. Previous research has shown that PAHs can be biodegraded. Size and structure, i.e., number and configuration of condensed rings, can affect compound disappearance. The focus of this research was to examine the relationship between resuspension and biodegradation of PAHs in lab scale slurry reactors. The rate and extent of contaminant release from the sediments into an uncontaminated water column was determined. Oxygen demand of initially anaerobic sediments were investigated. Then rate and extent of phenanthrene biodegradation was examined.
- OSTI ID:
- 111509
- Report Number(s):
- CONF-9504110-; TRN: 95:005009-0052
- Resource Relation:
- Conference: 21. Environmental Protection Agency (EPA) annual Risk Reduction Engineering Laboratory research symposium, Cincinnati, OH (United States), 4-6 Apr 1995; Other Information: PBD: 1995; Related Information: Is Part Of 21st Annual RREL research symposium: Abstract proceedings; PB: 398 p.
- Country of Publication:
- United States
- Language:
- English
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