EFFECT OF VARYING THE RATE OF PARTITIONING OF PHENANTHRENE IN NONAQUEOUS-PHASE LIQUIDS ON BIODEGRADATION IN SOIL SLURRIES

A study was conducted to determine the influence of varying the rates of partitioning of phenanthrene from nonaqueous-phase liquids to water on its biodegradation. Partitioning rates from dibutyl phthalate and 2,2,4,4,6,8,8-heptamethylnonane were rapid in slurries of soil or aquifer solids that were shaken and were affected by-the identity and volume of the nonaqueous-phase liquid, Concentrations of the surfactant Alfonic 810-60 that increased partitioning inhibited biodegradation. The rates of mass transfer from the, phthalate to water were not influenced by the identity of the environmental sample. Although the rate of mass transfer of phenanthrene did not limit its mineralization by microorganisms in the soil or aquifer solids, treatments that increased the rate of partitioning enhanced biodegradation, presumably because the treatment overcame some other factor that limited degradation of the hydrocarbon.