Grantee Research Project Results
2022 Progress Report: Enabling real-time, low-cost measurement of hazardous air pollutants
EPA Grant Number: R840425Title: Enabling real-time, low-cost measurement of hazardous air pollutants
Investigators: Isaacman-VanWertz, Gabriel , Kroll, Jesse H. , Papapostolou, Vasileios
Institution: Virginia Polytechnic Institute and State University , Massachusetts Institute of Technology
EPA Project Officer: Chung, Serena
Project Period: May 1, 2022 through May 12, 2025
Project Period Covered by this Report: May 1, 2022 through April 30,2023
Project Amount: $800,000
RFA: Measurement and Monitoring Methods for Air Toxics and Contaminants of Emerging Concern in the Atmosphere (2021) RFA Text | Recipients Lists
Research Category: Air Quality and Air Toxics
Objective:
The overarching goal of this work is the development, optimization, and demonstration of a novel technique for measuring hazardous air pollutants. This project couples multiple approaches of low-cost sensing with new technologies for sample enrichment and fast chromatographic separation. Central to this technique is the measurement and chemical characterization of analytes using a multidimensional array of low-cost sensors for volatile organic gases (VOCs). This project overcomes the sensitivity and selectivity limitations of existing low-cost sensors by developing two new front-ends. First, a novel inlet will enrich the analytes within the sample flow in real time, improving sensitivity of the sensors. This will be followed by a rapid inline gas chromatography (GC) column to provide some analyte separation, greatly improving selectivity of the measurement, and enabling the identification and quantification of individual hazardous air pollutants. This project includes the demonstration and validation of the developed technologies by deployment alongside instrumentation at existing sites in southern California where emissions of hazardous air pollutants might be expected to occur.
Progress Summary:
This reporting period included significant progress on all three central technologies being developed. Development and evaluation of the enriching inlet is approximately complete and is undergoing peer review for publication in the scientific literature. Analyte concentrations were enhanced by up to a factor of 47 times in sample flows between 0.2 and 5 sccm (higher enrichment at lower flows), with a descriptive model able to predict enrichment as a function of operating conditions. Development of the inline GC approach also saw significant advances, with demonstrated resolution of compounds differing by only a single carbon number in under one minute. Operating parameters of flow and sampling duration were tested across the proposed ranges, with further evaluation of GC column phase and dimensions planned for the next reporting period. An array of sensors sharing a common inlet was demonstrated and yielded detailed quantification of sensitivity of 12 different sensors to 10 different analytes, with relatively unique distributions of sensitivities for each compound. Together, these results advance the project toward a feasible complete prototype that incorporates all three developed and evaluation technologies for measurements of simple and complex mixtures, which will be explored in the next reporting period. By addressing shortcomings in the sensitivity and selectivity of low-cost sensors, the tools and techniques developed as part of this project and demonstrated in this reporting period are expected to expand access to measurements of hazardous air pollutants by researchers and members of the community.
Future Activities:
Activities in the next reporting period will be focused on advancing the development and evaluation of the in-line GC and the sensor array. Sensor array development will advance to evaluation of simple mixtures and ambient samples. A core goal of the next reporting period is the coupling of all three central components. Coupling the GC column with multiple low-cost sensors as a detector is expected in the next period, which will require overcoming engineering challenges posed by low flows. In-line GC data collected by the sensor array will represent a critical step toward full deployment. Once coupled, all three components will be operated as a complete prototype suitable for laboratory work, with a focus on optimizing co-dependent parameters such as flows and temperatures. A complete deployable package is expected in the third year of the project.
Journal Articles on this Report : 1 Displayed | Download in RIS Format
| Other project views: | All 2 publications | 2 publications in selected types | All 2 journal articles |
|---|
| Type | Citation | ||
|---|---|---|---|
|
|
Panji NS and Isaacman-VanWertz G. A Novel inlet for enriching concentrations of reactive organic gases in low sampling flows. Atmospheric Measurement Techniques Discussions 2023. doi:10.5194/amt-2023-102, in review. |
R840425 (2022) |
Exit |
Supplemental Keywords:
instrumentation, atmospheric gases, air quality, hazardous air pollutantsRelevant Websites:
none
Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.