Relationship between Organic Matter Content of Soil and the Sequestration of Phenanthrene

A study was conducted to determine the relationship between organic matter content of soil and the availability of aged phenanthrene. Phenanthrene was aged for 200 days in sterile samples of dissimilar soils, soils treated with H{sub 2}O{sub 2} to reduce the content of organic matter, and sand. Sequestration as measured by the extent of mineralization of phenanthrene by an added bacterium was appreciable in samples with >2.0% organic C, and the bioavailability of the hydrocarbon declined with time of aging. Sequestration was not evident in soils or sand with 2.0% organic C, but a small effect on rate was evident in soil and sand with 2.0% organic C and the least in sand. Aging as measured by a decline in extractability of 1-butanol was evident in all soils, although the rate was fastest in soil with >2.0% organic C. The volume occupied by pores of <10-{micro}m diameter was highermore » in soils containing more organic matter and was negligible in sand. The authors suggest that the organic matter content of soil is a major determinant of sequestration.« less