- 2025-07-09
Acid aerosol
Environmental Behavior and Control of Acidic Aerosols
Formation mechanism and physical properties
Acid aerosol refers to liquid/solid acidic particles with an aerodynamic diameter of ≤2.5μm (PM₂.₅), and its core characteristics are as follows:
Chemical composition:
Type Main ingredient Source
Sulfate aerosol (NH₄)₂SO₄/H₂SO₄ Coal-fired SO₂ oxidation (accounting for >60%)
Nitrate aerosol NH₄NO₃/HNO₃ Motor vehicle NOx conversion (accounting for 30%)
Particle size distribution:
Accumulation mode: 0.1-1μm (atmospheric residence time 7-30 days)
Acidity strength: pH 1.5-4.5 (measured in wet state)
Environmental migration and climate effects
■ Vertical transmission:
Tropopause penetration rate <5% (mainly distributed in the 0-5km atmosphere)
Global spread: East Asian emissions contribute 15-20% to North American deposition
■ Climate impact:
Cloud condensation nucleus (CCN) effect: increases cloud droplet concentration by 50-100%
Radiative forcing: -0.5W/m² (offsets greenhouse effect by 20%)
Ecological health risks
Exposure route Sensitive population Health damage (per 10μg/m³ increase in concentration)
Respiratory system Asthma patients Emergency visit rate ↑3.8% (sulfate aerosol)
Cardiovascular system Elderly Heart failure hospitalization rate ↑2.1%
Building Materials Limestone Monuments Corrosion rate accelerated by 300%
Pollution Control Technology
■ Source control:
Wet desulfurization: efficiency＞95% (export SO₂≤35mg/m³)
SCR denitrification: efficiency > 85% (export NOx ≤ 50mg/m³)
■ Endpoint protection:
| Equipment | Applicable scenarios | Acid aerosol removal rate |
|--------------|------------------|------------------|
| MF-1000 filter tank | Industrial plant fresh air | ＞90% (H₂SO₄ mist) |
| Electrostatic precipitator | Coal-fired power plant | ＞95% (PM₂.₅) |
