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Titolo:
Measuring chemical emissions using open-path Fourier transform infrared (OP-FTIR) spectroscopy and computer-assisted tomography
Autore:
Todd, LA; Ramanathan, M; Mottus, K; Katz, R; Dodson, A; Mihlan, G;
Indirizzi:
Univ N Carolina, Dept Environm Sci & Engn, Chapel Hill, NC 27599 USA Univ N Carolina Chapel Hill NC USA 27599 Engn, Chapel Hill, NC 27599 USA
Titolo Testata:
ATMOSPHERIC ENVIRONMENT
fascicolo: 11, volume: 35, anno: 2001,
pagine: 1937 - 1947
SICI:
1352-2310(2001)35:11<1937:MCEUOF>2.0.ZU;2-7
Fonte:
ISI
Lingua:
ENG
Soggetto:
LEAST-SQUARES METHODS; IMAGE-RECONSTRUCTION; AIR; ALGORITHMS; SYSTEM; GASES;
Keywords:
tomography; ammonia; swine waste;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Physical, Chemical & Earth Sciences
Citazioni:
27
Recensione:
Indirizzi per estratti:
Indirizzo: Todd, LA Univ N Carolina, Dept Environm Sci & Engn, Chapel Hill, NC 27599 USA Univ N Carolina Chapel Hill NC USA 27599 apel Hill, NC 27599 USA
Citazione:
L.A. Todd et al., "Measuring chemical emissions using open-path Fourier transform infrared (OP-FTIR) spectroscopy and computer-assisted tomography", ATMOS ENVIR, 35(11), 2001, pp. 1937-1947

Abstract

This paper reports on a field study that was part of a large-scale, multi-seasonal research study with the North Carolina Department of Environment, Health, and Natural Resources, to measure nitrogen emissions from an intensive swine confinement facility. The study measured emission rates using tracer gases and a horizontal network of open-path Fourier transform infrared (FTIR) optical rays placed less than a meter above the surface of an approximately 6 acre intensive swine waste lagoon in Eastern North Carolina. Thisnetwork of rays simultaneously monitored the ammonia and the tracer gases every 2 min. The open-path measurements were combined with the mathematicalmapping techniques of computer-assisted tomography (CAT) to create two-dimensional concentration maps of the gases for the entire lagoon surface. Forthis study, a ratioing technique was applied to the tomographic concentration maps to estimate the nitrogen emission rates (from ammonia) using knowntracer emission rates. The average concentrations of ammonia measured in August, November, and May were 0.81, 0.25, and 0.74 ppm, respectively. In general, ammonia concentrations were lowest at the center of the lagoon and could vary across a lagoon from 2 to 4 times depending upon the time of the day and the meteorological conditions. Emission rates were only calculated for November and May, up until midnight. In November 1997, the average fluxwas 1910 mug Nm(-2)-min(-1)(range 542-4695 mug Nm(-2)-min(-1)) and in May the average flux was 4775 mug Nm(-2)-min(-1)(range 2572-8499 mug Nm(-2)-min(-1)). This study was important because it not only provided nitrogen emission rate measurements using a new technology which can measure concentrations over large areas in real time, it was the first large-scale outdoor field study using this application. (C) 2001 Elsevier Science Ltd. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 19/01/20 alle ore 14:26:24