Aggregated particles caused by instrument artifact

Loading...
Thumbnail Image

Authors

Pierce, Ashley M.
Loria-Salazar, Sandra M.
Arnott, W. Patrick
Edwards, Grant C.
Miller, Matthieu B.
Gustin, Mae S.

Issue Date

2018

Type

Article

Language

Keywords

Research Projects

Organizational Units

Journal Issue

Alternative Title

Abstract

Previous studies have indicated that superaggregates, clusters of aggregates of soot primary particles, can be formed in large-scale turbulent fires. Due to lower effective densities, higher porosity, and lower aerodynamic diameters, superaggregates may pass through inlets designed to remove particles < 2.5 mu m in aerodynamic diameter (PM2.5). Ambient particulate matter samples were collected at Peavine Peak, NV, USA (2515 m) northwest of Reno, NV, USA from June to November 2014. The Teledyne Advanced Pollution Instrumentation (TAPI) 602 Beta(Plus) particulate monitor was used to collect PM2.5 on two filter types. During this time, aggregated particles > 2.5 mu m in aerodynamic diameter were collected on 36 out of 158 sample days. On preliminary analysis, it was thought that these aggregated particles were superaggregates, depositing past PM10 (particles < 10 mu m in aerodynamic diameter) pre-impactors and PM2.5 cyclones. However, further analysis revealed that these aggregated particles were dissimilar to superaggregates observed in previous studies, both in morphology and in elemental composition. To determine if the aggregated particles were superaggregates or an instrument artifact, samples were investigated for the presence of certain elements, the occurrence of fires, high relative humidity and wind speeds, as well as the use of generators on site. Samples with aggregated particles, referred to as aggregates, were analyzed using a scanning electron microscope for size and shape and energy dispersive X-ray spectroscopy was used for elemental analysis. It was determined, based on the high amounts of aluminum present in the aggregate samples, that a sampling artifact associated with the sample inlet and prolonged, high wind events was the probable reason for the observed aggregates.

Description

Citation

Pierce, A. M., Loría-Salazar, S. M., Arnott, W. P., Edwards, G. C., Miller, M. B., & Gustin, M. S. (2018). Aggregated particles caused by instrument artifact. Atmospheric Measurement Techniques, 11(4), 2225–2237. doi:10.5194/amt-11-2225-2018

Publisher

Journal

Volume

Issue

PubMed ID

ISSN

1867-1381

EISSN

Collections