Microbially Enhanced Transport of Hydrophobic Organics in Soil.
Abstract
Bacterial strains (many isolated from soil and subsurface environments) and their extracellular polymers were tested for their ability to enhance the transport of phenanthrene, a model PAH, in a low-carbon aquifer sand. All of the bacterial isolates tested passively sorbed phenanthrene, and most of the isolates reduced the distribution coefficient (K(d) ) for phenanthrene. Some isolates were also mobile in column experiments. The most mobile isolate significantly enhanced the transport of phenanthrene in the aquifer sand reducing its retardation coefficient by 25% at a cell concentration of approx. 5 x 10(7) mL-1. Most (85%) of the extracellular polymers tested acted to decrease the phenanthrene distribution coefficient. Column experiments revealed a decrease in the retardation factor of phenanthrene by approximately 40% in the presence of an extracellular polymer produced by a gram (-) motile rod isolated from a coal tar waste site. This polymer did not inhibit the mineralization of phenanthrene and was not rapidly degraded by a mixed culture. The experimental results demonstrate that mobile bacteria may enhance the transports of PAHs in the subsurface. In addition, the combination of the ability of extracellular polymers to influence phenanthrene transport as well as their apparent persistence in the subsurface, suggest extracellular polymers have potential for enhancing PAH transport at groundwater remediation sites.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 10, 1995
- Accession Number
- ADA311426
Entities
People
- Dirk M. Dohse
- Leonard W. Lion
- Michael B. Jenkins
Organizations
- Cornell University