luokai0 Air Quality Expert
Before Starting
- Source characterization or receptor modeling?
- Regulatory compliance or research focus?
- Which pollutants? (criteria, HAPs, GHGs)
Core Expertise Areas
Pollutants and Standards
Criteria pollutants: CO, NOx, SOx, PM2.5, PM10, ozone, lead under NAAQS. HAPs: hazardous air pollutants, 187 listed under Clean Air Act. GHGs: CO2, CH4, N2O, HFCs regulated under climate policy. NAAQS: national ambient air quality standards, primary and secondary standards. AQI: air quality index 0-500, communicates health risk to public.
Emission Sources
Point sources: stacks, vents, identifiable single emission points. Area sources: fugitive emissions, agricultural, small sources aggregated. Mobile sources: vehicles, aircraft, trains, significant urban contribution. Emission factors: AP-42 database provides emission factors by source category. Continuous monitoring: CEMS measure emissions in real time for major sources.
Atmospheric Dispersion
Gaussian plume: C = Q over 2 pi sigma_y sigma_z u times exponential terms. Stability classes: Pasquill-Gifford A through F, neutral D most common. Mixing height: limits vertical dispersion, varies diurnally. AERMOD: EPA preferred model for near-field dispersion from industrial sources. CALPUFF: Lagrangian puff model for long range and complex terrain.
Emission Controls
Electrostatic precipitator: charge and collect particles, over 99% efficiency. Fabric filter: baghouse, PM control, efficiency depends on fabric and cleaning. Wet scrubber: spray liquid absorbs gas pollutants and large particles. SCR: selective catalytic reduction, NOx control using ammonia over catalyst. Thermal oxidizer: combust VOCs and HAPs at high temperature.
Best Practices
- Use site-specific meteorological data for dispersion modeling
- Validate emission inventory with source testing periodically
- Apply best available control technology for new major sources
- Consider secondary pollutant formation from primary emissions
Common Pitfalls
| Pitfall | Fix |
|---|---|
| Default met data instead of site-specific | Use on-site or nearest representative met station |
| Ignoring building downwash | Include building downwash for stacks near tall structures |
| Wrong emission factor for source type | Match AP-42 table to actual process conditions |
| Missing fugitive emissions | Fugitive sources often exceed stack emissions |
Related Skills
- environmental-remediation-expert
- water-treatment-expert
- climatology-expert