Sensitivity analysis on parameters and processes affecting vapor intrusion risk

Handle URI:
http://hdl.handle.net/10754/599594
Title:
Sensitivity analysis on parameters and processes affecting vapor intrusion risk
Authors:
Picone, Sara; Valstar, Johan; van Gaans, Pauline; Grotenhuis, Tim; Rijnaarts, Huub
Abstract:
A one-dimensional numerical model was developed and used to identify the key processes controlling vapor intrusion risks by means of a sensitivity analysis. The model simulates the fate of a dissolved volatile organic compound present below the ventilated crawl space of a house. In contrast to the vast majority of previous studies, this model accounts for vertical variation of soil water saturation and includes aerobic biodegradation. The attenuation factor (ratio between concentration in the crawl space and source concentration) and the characteristic time to approach maximum concentrations were calculated and compared for a variety of scenarios. These concepts allow an understanding of controlling mechanisms and aid in the identification of critical parameters to be collected for field situations. The relative distance of the source to the nearest gas-filled pores of the unsaturated zone is the most critical parameter because diffusive contaminant transport is significantly slower in water-filled pores than in gas-filled pores. Therefore, attenuation factors decrease and characteristic times increase with increasing relative distance of the contaminant dissolved source to the nearest gas diffusion front. Aerobic biodegradation may decrease the attenuation factor by up to three orders of magnitude. Moreover, the occurrence of water table oscillations is of importance. Dynamic processes leading to a retreating water table increase the attenuation factor by two orders of magnitude because of the enhanced gas phase diffusion. © 2012 SETAC.
Citation:
Picone S, Valstar J, van Gaans P, Grotenhuis T, Rijnaarts H (2012) Sensitivity analysis on parameters and processes affecting vapor intrusion risk. Environmental Toxicology and Chemistry 31: 1042–1052. Available: http://dx.doi.org/10.1002/etc.1798.
Publisher:
Wiley-Blackwell
Journal:
Environmental Toxicology and Chemistry
Issue Date:
30-Mar-2012
DOI:
10.1002/etc.1798
PubMed ID:
22392684
Type:
Article
ISSN:
0730-7268
Sponsors:
The research work described in this article was funded by the award for KAUST Center-in-Development SOWACOR.
Appears in Collections:
Publications Acknowledging KAUST Support

Full metadata record

DC FieldValue Language
dc.contributor.authorPicone, Saraen
dc.contributor.authorValstar, Johanen
dc.contributor.authorvan Gaans, Paulineen
dc.contributor.authorGrotenhuis, Timen
dc.contributor.authorRijnaarts, Huuben
dc.date.accessioned2016-02-28T05:53:59Zen
dc.date.available2016-02-28T05:53:59Zen
dc.date.issued2012-03-30en
dc.identifier.citationPicone S, Valstar J, van Gaans P, Grotenhuis T, Rijnaarts H (2012) Sensitivity analysis on parameters and processes affecting vapor intrusion risk. Environmental Toxicology and Chemistry 31: 1042–1052. Available: http://dx.doi.org/10.1002/etc.1798.en
dc.identifier.issn0730-7268en
dc.identifier.pmid22392684en
dc.identifier.doi10.1002/etc.1798en
dc.identifier.urihttp://hdl.handle.net/10754/599594en
dc.description.abstractA one-dimensional numerical model was developed and used to identify the key processes controlling vapor intrusion risks by means of a sensitivity analysis. The model simulates the fate of a dissolved volatile organic compound present below the ventilated crawl space of a house. In contrast to the vast majority of previous studies, this model accounts for vertical variation of soil water saturation and includes aerobic biodegradation. The attenuation factor (ratio between concentration in the crawl space and source concentration) and the characteristic time to approach maximum concentrations were calculated and compared for a variety of scenarios. These concepts allow an understanding of controlling mechanisms and aid in the identification of critical parameters to be collected for field situations. The relative distance of the source to the nearest gas-filled pores of the unsaturated zone is the most critical parameter because diffusive contaminant transport is significantly slower in water-filled pores than in gas-filled pores. Therefore, attenuation factors decrease and characteristic times increase with increasing relative distance of the contaminant dissolved source to the nearest gas diffusion front. Aerobic biodegradation may decrease the attenuation factor by up to three orders of magnitude. Moreover, the occurrence of water table oscillations is of importance. Dynamic processes leading to a retreating water table increase the attenuation factor by two orders of magnitude because of the enhanced gas phase diffusion. © 2012 SETAC.en
dc.description.sponsorshipThe research work described in this article was funded by the award for KAUST Center-in-Development SOWACOR.en
dc.publisherWiley-Blackwellen
dc.subjectBiodegradationen
dc.subjectDynamic processesen
dc.subjectModelingen
dc.subjectVapor intrusionen
dc.subjectVariable soil moistureen
dc.titleSensitivity analysis on parameters and processes affecting vapor intrusion risken
dc.typeArticleen
dc.identifier.journalEnvironmental Toxicology and Chemistryen
dc.contributor.institutionWageningen University and Research Centre, Wageningen, Netherlandsen
dc.contributor.institutionDeltares, Delft, Netherlandsen

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