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This content will become publicly available on July 1, 2026

Title: Continuous Monitoring of Sulfur Dioxide Removal Using K-Band Molecular Rotational Resonance Spectroscopy
Sulfur dioxide (SO2), an air pollutant, poses significant threats to both public health and the environment. It is one of the six air pollutants regulated by the U.S. Environmental Protection Agency (EPA) under the Clean Air Act. In efforts to determine the application of molecular rotational resonance (MRR) spectroscopy for monitoring SO2and its removal from point sources, a K-band MRR technique was evaluated. This method was applied to measure the products of heated mixtures of SO2and oxygen (O2) in the presence of ammonium metavanadate (NH4VO3) as a catalyst. The observed MRR spectrum revealed the presence of SO2, water vapor (H2O), and ammonia (NH3) due to the sensitivity of MRR to only polar species. SO2removal was further confirmed by the disappearance of SO2as NH3formed. The work presented here analyzed the measurements of SO2and validated K-band MRR for monitoring SO2removal. It was observed that the K-band MRR maintains its linearity and other polar species in the mixture did not interfere with MRR signature of SO2. The limit of detection, better than 1%, was determined by evaluating targeted K-band MRR signal response of SO2removal obtained at varying partial pressures of SO2in the mixture and using the MRR signal of pure SO2at 3 mTorr as a reference (100%). Additionally, the results showed that the accuracy and precision of K-band MRR for measuring SO2partial pressure were satisfactory.  more » « less
Award ID(s):
2213264
PAR ID:
10625163
Author(s) / Creator(s):
; ; ; ;
Editor(s):
Kazarian, S
Publisher / Repository:
Applied Spectroscopy
Date Published:
Journal Name:
Applied Spectroscopy
Volume:
79
Issue:
7
ISSN:
0003-7028
Page Range / eLocation ID:
1155 to 1163
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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