Solubilization and biodegradation of polycyclic aromatic hydrocarbon compounds in soil-water suspensions with surfactants

Miscellaneous · Wed Jan 01 00:00:00 EST 1992

OSTI ID:6243569

Laha, S

Hydrophobic organic compounds (HOCs) sorb strongly onto soil and sediment material, and the effectiveness of microbial treatment can be diminished by HOC phase partitioning and decreased substrate accessibility to microorganisms. Surfactant addition has been suggested as a technique for decreasing the interfacial tension and partitioning of the HOC with soil, and thereby increasing HOC mobility and bioavailability. However, this study indicates that nonionic surfactant solubilization of HOCs from soil may not be beneficial for the enhancement of soil bioremediation. The solubilization and microbial degradation of phenanthrene, a three-ring polycyclic aromatic hydrocarbon (PAH) compound, was examined in various soil-water systems with commercially-available surface-active agents. This was accomplished by a series of batch tests using radiolabeled techniques. The purpose of surfactant addition was to assess the effect of surfactant solubilization of PAHs on their biodegradation. For soil-water suspensions without surfactant approximately 50-60% of the phenanthrene was mineralized over the course of ten weeks. The addition of nonionic surface-active agents was observed not to be beneficial for microbial mineralization of phenanthrene in the soil-water systems, and for supra-CMC surfactant doses phenanthrene mineralization was completely inhibited for all the surfactants tested. Sub-CMC levels of surfactant in the soil-water systems generally did not have an inhibitory effect on phenanthrene mineralization, but neither did such doses serve to enhance the rate of degradation, which proceeded most rapidly in the absence of any surfactant. Companion tests suggest that the supra-CMC inhibitory effect is not a toxicity phenomenon, per se, of the surfactant or micellized PAH. An assessment of the results from the various experiments suggest that the inhibitory effect is probably related to a reversible physiological surfactant micelle-bacteria interaction.

• Research Organization: Carnegie-Mellon Univ., Pittsburgh, PA (United States)
• OSTI ID: 6243569
• Resource Relation: Other Information: Thesis (Ph.D.)
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
POLYCYCLIC AROMATIC HYDROCARBONS
BIODEGRADATION
SEDIMENTS
REMEDIAL ACTION
SOILS
SURFACTANTS
BIOLOGICAL EFFECTS
MICELLAR SYSTEMS
MICROORGANISMS
PHENANTHRENE
TRACER TECHNIQUES
AROMATICS
CHEMICAL REACTIONS
CONDENSED AROMATICS
DECOMPOSITION
HYDROCARBONS
ISOTOPE APPLICATIONS
ORGANIC COMPOUNDS
540220* - Environment
Terrestrial- Chemicals Monitoring & Transport- (1990-)