Desorption of [14C]Naphthalene from Bioremediated and Nonbioremediated Soils Contaminated with Creosote Compounds

Abstract

Bioremediation changes the quantity and nature of the contaminant matrix remaining in soil, because some compounds are selectively degraded while others remain undegraded. It was hypothesized that changes to the contaminant matrix may alter the chemical and physical properties of the soil, such that subsequent desorption of a specific PAH compound would be altered. Desorption of [14C]naphthalene from two creosote-contaminated soils was measured before and after bioremediation. Although the bioremediation treatment removed the lower-molecular weight components, increasing the average molecular weight of the residual creosote by 10−36%, partition coefficients based on the mass of organic carbon in the soil were unaffected. Partition coefficients for naphthalene in soil organic matter were 4.6−8.3 times smaller than in the creosote contaminant. When partitioning was modeled as the sum of the contributions of the nonaqueous phase contaminant and the soil organic matter, the partition coefficients for the creo...