DOI: 10.1016/j.watres.2018.11.038
Scopus记录号: 2-s2.0-85057436076
论文题名: Modeling capillary fringe effect on petroleum vapor intrusion from groundwater contamination
作者: Yao Y. ; Mao F. ; Xiao Y. ; Luo J.
刊名: Water Research
ISSN: 431354
出版年: 2019
起始页码: 111
结束页码: 119
语种: 英语
英文关键词: Capillary fringe
; Groundwater contamination
; Numerical simulations
; Petroleum vapor intrusion
; Smear zone
Scopus关键词: Air quality
; Biodegradation
; Computer simulation
; Contamination
; Gasoline
; Groundwater
; Hydrocarbons
; Indoor air pollution
; Moisture control
; Numerical models
; Risk assessment
; Soil moisture
; Source separation
; Volatile organic compounds
; Aerobic biodegradation
; Capillary fringe
; Groundwater contaminants
; Groundwater contamination
; Indoor air concentration
; Separation distances
; Soil gas concentration
; Vapor intrusion
; Groundwater pollution
; ground water
; hydrocarbon
; oxygen
; petroleum
; air quality
; biodegradation
; capillary fringe
; cleanup
; concentration (composition)
; groundwater pollution
; hydrocarbon
; indoor air
; modeling
; numerical method
; numerical model
; petroleum hydrocarbon
; simulation
; soil gas
; soil moisture
; volatile organic compound
; air quality
; ambient air
; Article
; biodegradation
; comparative study
; controlled study
; diffusivity
; gas transport
; moisture
; oxygen concentration
; porosity
; priority journal
; rate constant
; soil
; soil moisture
; soil respiration
; soil water content
; steady state
; stoichiometry
; water contamination
; water vapor
; United States
英文摘要: At contaminated sites, indoor inhalation of volatile organic compounds from groundwater contamination, known as vapor intrusion (VI), is an important exposure pathway to determine groundwater cleanup level. Based on empirical analysis, US EPA concluded that there is a low probability for vapors from fuel hydrocarbons dissolved in groundwater to induce indoor concentrations that exceed risk-based standards, and recommended 6 feet vertical building-source separation distance as the risk screening tool for such cases. In this study, we examine this recommendation by performing numerical modeling to investigate the detailed effects of the capillary fringe on petroleum vapor biodegradation and attenuation. First, the numerical model is validated by comparison with laboratory data and field measurements in US EPA's database. Then the verified model is used to simulate two scenarios involving the capillary fringe effect, one with a groundwater source at various depth and the other with a soil gas source located above the groundwater level. For a groundwater contaminant source, the capillary fringe plays a significant role in VI by controlling the soil moisture content and oxygen availability, thus affecting the soil gas concentration biodegradation and attenuation. Specifically, the capillary fringe effect can significantly decrease the indoor air concentration by decreasing upward diffusion rates of hydrocarbon, increasing the thickness of the aerobic zone, and enhancing aerobic biodegradation. As a result, it is highly unlikely for sources located at groundwater level to induce unacceptable vapor intrusion risks, supporting US EPA's recommendation. Moreover, the simulations suggest that the vertical smear zone of residual light non-aqueous liquid contamination, induced by temporal fluctuations of groundwater level, may lead to a potential threat to indoor air quality for a short vertical source-building separation distance, and thus requires more attention. The sensitivity test of the numerical model also indicates that it is the vertical separation distance between building foundation and the top of the smear zone instead of the smear zone thickness that should be given more attention during the investigation. © 2018 Elsevier Ltd Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/122110
Appears in Collections: 气候变化事实与影响
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作者单位: MOE Key Lab of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China; Research Center for Air Pollution and Health, Zhejiang University, Hangzhou, 310058, China; Institute of Environmental Health, Zhejiang University, Hangzhou, 310058, China; School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332, United States
Recommended Citation:
Yao Y.,Mao F.,Xiao Y.,et al. Modeling capillary fringe effect on petroleum vapor intrusion from groundwater contamination[J]. Water Research,2019-01-01