Applications and Limitations of Quantifying Speciated and Source-Apportioned VOCs with Metal Oxide Sensors

While low-cost air quality sensor quantification has improved tremendously in recent years, speciated hydrocarbons have received little attention beyond total lumped volatile organic compounds (VOCs) or total non-methane hydrocarbons (TNMHCs). In this work, we attempt to use two broad response metal...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	Kristen Okorn, Michael Hannigan
Formato:	article
Lenguaje:	EN
Publicado:	MDPI AG 2021
Materias:	low-cost sensors volatile organic compounds positive matrix factorization source attribution VOC speciation Meteorology. Climatology QC851-999
Acceso en línea:	https://doaj.org/article/5827141d65e94263a6bb2d9300cb94a4
Etiquetas:	Agregar Etiqueta Sin Etiquetas, Sea el primero en etiquetar este registro!

id	oai:doaj.org-article:5827141d65e94263a6bb2d9300cb94a4
record_format	dspace
spelling	oai:doaj.org-article:5827141d65e94263a6bb2d9300cb94a42021-11-25T16:43:57ZApplications and Limitations of Quantifying Speciated and Source-Apportioned VOCs with Metal Oxide Sensors10.3390/atmos121113832073-4433https://doaj.org/article/5827141d65e94263a6bb2d9300cb94a42021-10-01T00:00:00Zhttps://www.mdpi.com/2073-4433/12/11/1383https://doaj.org/toc/2073-4433While low-cost air quality sensor quantification has improved tremendously in recent years, speciated hydrocarbons have received little attention beyond total lumped volatile organic compounds (VOCs) or total non-methane hydrocarbons (TNMHCs). In this work, we attempt to use two broad response metal oxide VOC sensors to quantify a host of speciated hydrocarbons as well as smaller groups of hydrocarbons thought to be emanating from the same source or sources. For sensors deployed near oil and gas facilities, we utilize artificial neural networks (ANNs) to calibrate our low-cost sensor signals to regulatory-grade measurements of benzene, toluene, and formaldehyde. We also use positive matrix factorization (PMF) to group these hydrocarbons along with others by source, such as wet and dry components of oil and gas operations. The two locations studied here had different sets of reference hydrocarbon species measurements available, helping us determine which specific hydrocarbons and VOC mixtures are best suited for this approach. Calibration fits on the upper end reach above R<sup>2</sup> values of 0.6 despite the parts per billion (ppb) concentration ranges of each, which are magnitudes below the manufacturer’s prescribed detection limits for the sensors. The sensors generally captured the baseline trends in the data, but failed to quantitatively estimate larger spikes that occurred intermittently. While compounds with high variability were not suited for this method, its success with several of the compounds studied represents a crucial first step in low-cost VOC speciation. This work has important implications in improving our understanding of the links between health and environment, as different hydrocarbons will have varied consequences in the human body and atmosphere.Kristen OkornMichael HanniganMDPI AGarticlelow-cost sensorsvolatile organic compoundspositive matrix factorizationsource attributionVOC speciationMeteorology. ClimatologyQC851-999ENAtmosphere, Vol 12, Iss 1383, p 1383 (2021)
institution	DOAJ
collection	DOAJ
language	EN
topic	low-cost sensors volatile organic compounds positive matrix factorization source attribution VOC speciation Meteorology. Climatology QC851-999
spellingShingle	low-cost sensors volatile organic compounds positive matrix factorization source attribution VOC speciation Meteorology. Climatology QC851-999 Kristen Okorn Michael Hannigan Applications and Limitations of Quantifying Speciated and Source-Apportioned VOCs with Metal Oxide Sensors
description	While low-cost air quality sensor quantification has improved tremendously in recent years, speciated hydrocarbons have received little attention beyond total lumped volatile organic compounds (VOCs) or total non-methane hydrocarbons (TNMHCs). In this work, we attempt to use two broad response metal oxide VOC sensors to quantify a host of speciated hydrocarbons as well as smaller groups of hydrocarbons thought to be emanating from the same source or sources. For sensors deployed near oil and gas facilities, we utilize artificial neural networks (ANNs) to calibrate our low-cost sensor signals to regulatory-grade measurements of benzene, toluene, and formaldehyde. We also use positive matrix factorization (PMF) to group these hydrocarbons along with others by source, such as wet and dry components of oil and gas operations. The two locations studied here had different sets of reference hydrocarbon species measurements available, helping us determine which specific hydrocarbons and VOC mixtures are best suited for this approach. Calibration fits on the upper end reach above R<sup>2</sup> values of 0.6 despite the parts per billion (ppb) concentration ranges of each, which are magnitudes below the manufacturer’s prescribed detection limits for the sensors. The sensors generally captured the baseline trends in the data, but failed to quantitatively estimate larger spikes that occurred intermittently. While compounds with high variability were not suited for this method, its success with several of the compounds studied represents a crucial first step in low-cost VOC speciation. This work has important implications in improving our understanding of the links between health and environment, as different hydrocarbons will have varied consequences in the human body and atmosphere.
format	article
author	Kristen Okorn Michael Hannigan
author_facet	Kristen Okorn Michael Hannigan
author_sort	Kristen Okorn
title	Applications and Limitations of Quantifying Speciated and Source-Apportioned VOCs with Metal Oxide Sensors
title_short	Applications and Limitations of Quantifying Speciated and Source-Apportioned VOCs with Metal Oxide Sensors
title_full	Applications and Limitations of Quantifying Speciated and Source-Apportioned VOCs with Metal Oxide Sensors
title_fullStr	Applications and Limitations of Quantifying Speciated and Source-Apportioned VOCs with Metal Oxide Sensors
title_full_unstemmed	Applications and Limitations of Quantifying Speciated and Source-Apportioned VOCs with Metal Oxide Sensors
title_sort	applications and limitations of quantifying speciated and source-apportioned vocs with metal oxide sensors
publisher	MDPI AG
publishDate	2021
url	https://doaj.org/article/5827141d65e94263a6bb2d9300cb94a4
work_keys_str_mv	AT kristenokorn applicationsandlimitationsofquantifyingspeciatedandsourceapportionedvocswithmetaloxidesensors AT michaelhannigan applicationsandlimitationsofquantifyingspeciatedandsourceapportionedvocswithmetaloxidesensors
_version_	1718413017991872512

Applications and Limitations of Quantifying Speciated and Source-Apportioned VOCs with Metal Oxide Sensors

Ejemplares similares