@article{4e3383e0fcfc11dd83f3000ea68e967b,
title = "Soil Physical Constraints on Intrinsic Biodegradation of Petroleum Vapors in a Layered Subsurface",
abstract = "Intrinsic biodegradation of organic contaminants in the soil vadose zone depends on site-specific soil properties controlling biophysical and geochemical interactions within the soil pore space. In this study we evaluated the effect of soil texture and moisture conditions on aerobic biodegradation in a deep and highly layered vadose zone contaminated with petroleum hydrocarbons. Soil slurry experiments on benzene biodegradation were used for determining the relative potential for hydrocarbon biodegradation in 100 soil samples collected from 2-16 m below ground surface. Regardless of nutrient-poor and calcareous subsoil conditions, the results showed a significant aerobic biodegradation potential. Average first-order rate constants (k1) ranged from 0 to 5 d-1 and varied significantly across soil types in the order sandy loam > fine sand > limestone. Within samples with high biodegradation potential, soil moisture conditions were controlling an upper boundary of the aerobic microbial activity, due to a close link between water content and the potential for oxygen diffusion in the soil. The results suggest soil texture and moisture conditions to be governing the potential for aerobic intrinsic biodegradation in the deep vadose zone. As a result, management of petroleum hydrocarbon spill sites will benefit from site-specific conceptual models in which the vadose zone is divided into geological compartments with different biophysical potential for biodegradation and bioremediation.",
keywords = "Um{\ae}ttet zone, Jordtekstur, Vandindhold, Kulbrinteforurening, Bioremediering, Biologisk nedbrydning, Vadose zone, Soil texture, Soil water content, Hydrocarbon contamination, Bioremediation, Biodegradation",
author = "Kristensen, {Andreas Houlberg} and Kaj Henriksen and Lars Mortensen and Scow, {Kate M.} and Per M{\o}ldrup",
year = "2010",
doi = "10.2136/vzj2009.0010",
language = "English",
volume = "9",
pages = "137--147",
journal = "Vadose Zone Journal",
issn = "1539-1663",
publisher = "GeoScienceWorld",
number = "1",
}