title: A numerical investigation of oxygen concentration dependence on biodegradation rate laws in vapor intrusion.
abstract: In subsurface vapor intrusion, aerobic biodegradation has been considered as a major environmental factor that determines the soil gas concentration attenuation factors for contaminants such as petroleum hydrocarbons. The site investigation has shown that oxygen can play an important role in this biodegradation rate, and this paper explores the influence of oxygen concentration on biodegradation reactions included in vapor intrusion (VI) models. Two different three dimensional (3-D) numerical models of vapor intrusion were explored for their sensitivity to the form of the biodegradation rate law. A second order biodegradation rate law, explicitly including oxygen concentration dependence, was introduced into one model. The results indicate that the aerobic/anoxic interface depth is determined by the ratio of contaminant source vapor to atmospheric oxygen concentration, and that the contaminant concentration profile in the aerobic zone was significantly influenced by the choice of rate law.
authors.affiliation: IJRC-PTS, MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
authors.forename: Yijun
authors.initials: Y
authors.lastname: Yao
authors.forename: Rui
authors.initials: R
authors.lastname: Shen
authors.forename: Kelly G
authors.initials: KG
authors.lastname: Pennel
authors.forename: Eric M
authors.initials: EM
authors.lastname: Suuberg
mesh_terms: D001673:Biodegradation, Environmental; D004785:Environmental Pollutants / Q000378:metabolism*; D008962:Models, Theoretical; D010100:Oxygen / Q000378:metabolism*
chemical_list: D004785:Environmental Pollutants; D010100:Oxygen