Air contains a wide variety of pollutants, and their concentrations and chemical reactions can change with emission sources, meteorological conditions, and atmospheric transport. Assistant Professor Chieh-Heng Wang's research is grounded in analytical chemistry and atmospheric monitoring. Through sampling, instrumental analysis, and data interpretation, his work examines changes in volatile organic compounds, ozone, and related pollutants in the environment.
His research covers pollutant measurement methods, emission investigations at industrial and waste-treatment facilities, and analysis of ozone precursors. By providing more accurate monitoring data, these studies establish a scientific foundation for air-pollution research and environmental management.
Volatile Organic Compounds and Atmospheric Monitoring
Volatile organic compounds, commonly referred to as VOCs, are an important focus of atmospheric pollution research. Different VOCs may originate from industrial processes, combustion, transportation, waste treatment, and other anthropogenic or natural sources. They may also participate in photochemical reactions in the atmosphere.
Professor Wang's research focuses on the sampling, separation, identification, and concentration analysis of VOCs. Analytical techniques including gas chromatography, flame ionization detection, and mass spectrometry are used to characterize pollutant composition and changes over time.
Ozone and Precursor Research
Ground-level ozone is not emitted directly in large quantities from pollution sources. Instead, it is formed through a series of sunlight-driven reactions involving nitrogen oxides and volatile organic compounds. Therefore, effective ozone management requires more than simply monitoring ozone concentrations; it also requires an understanding of the types, concentrations, and reactivity of different precursor compounds.
Related studies analyze the reactivity of organic precursors to investigate the conditions that contribute to high-ozone events and to evaluate the possible effects of different emission-reduction measures. This helps establish ozone-control strategies based on more comprehensive chemical measurements and data analysis.
Industrial Emissions and Pollution Source Investigation
Industrial areas, municipal waste incinerators, and landfills may emit a variety of volatile organic compounds. Because emission compositions are complex and are influenced by wind direction, sampling height, and atmospheric dispersion, pollution-source investigations require the integration of multiple sampling tools and analytical methods.
Professor Wang has participated in studies using unmanned aerial vehicles to investigate incinerator plumes and landfill emissions. Air samples collected at different altitudes are analyzed to determine VOC composition and pollution characteristics. This approach helps overcome some of the limitations of traditional ground-based monitoring stations and improves the completeness of pollution-source identification.
Passive Sampling and Online Measurement Technologies
Different environmental-monitoring applications require suitable sampling and analytical approaches. Online monitoring provides continuous measurements of concentration changes and helps capture the temporal characteristics of pollution events. Passive sampling, in contrast, does not require continuous pumping equipment and is suitable for collecting pollutants over longer periods at multiple locations.
Related research has developed dual-sorbent passive-sampling methods for a range of toxic volatile organic compounds and validated these methods using on-site online measurements. Comparing multiple measurement techniques can improve the reliability and flexibility of environmental-monitoring results.
Odor Pollution and Rapid Analysis
Industrial odors are often produced by mixtures of multiple compounds. Pollution events may occur briefly and may change rapidly with wind direction, creating a need for analytical methods that combine rapid response with accurate compound identification.
Research has applied mass-spectrometry techniques with different analytical speeds and resolutions to investigate volatile organic compounds in industrial pollution plumes. Rapid-response instruments can capture real-time changes in pollution plumes, while higher-resolution analytical methods provide more detailed compound identification. Combining these approaches enables a more complete characterization of odor-pollution events.
Major Research Areas
- Sampling and analysis of volatile organic compounds
- Ozone and organic precursor reactivity
- Monitoring of non-methane hydrocarbons
- Gas chromatography and mass spectrometry
- Industrial emissions and odor-pollution investigations
- Pollution monitoring at incinerators and landfills
- Passive sampling and online measurement technologies
Connecting Measurement Data with Environmental Management
Effective air-pollution management depends on reliable measurement data. Every stage of the monitoring process— from sampling location and analytical methods to instrument calibration and interpretation of results—can affect the accuracy of environmental measurements.
Analytical chemistry and atmospheric-monitoring technologies make it possible to identify pollutant types, emission sources, and changes in concentration more clearly. These data can support researchers and environmental-management agencies in evaluating pollution events, control strategies, and improvement measures.
Teaching and Talent Development
Training in air-pollution monitoring and control requires students to understand pollutant characteristics, sampling methods, analytical instruments, and environmental data. In addition to learning the principles of chemical analysis, students develop practical skills in laboratory operation, quality control, data processing, and interpretation of results.
These capabilities can be applied in environmental monitoring, air-quality management, instrumental analysis, industrial pollution prevention, and research institutions. Through hands-on measurement, students learn to understand the scientific evidence behind environmental issues.