1. Masking Method
- Principle: Mixing stronger fragrances with odor to make it tolerable.
- Application: Quick, temporary solution for low-concentration odors (~2.5), such as unorganized emission sources.
- Advantages: Fast, flexible, low-cost.
- Disadvantages: Odor substances remain untreated.
2. Dilution and Diffusion Method
- Principle: Releasing gases via chimneys or diluting with odorless air to lower odor concentration.
- Application: Medium and low concentrations with organized emissions.
- Advantages: Simple equipment, low cost.
- Disadvantages: Weather dependency; odor persists.
3. Thermal and Catalytic Combustion
- Principle: Complete combustion of odor substances at high temperatures.
- Application: High concentration, small volume of flammable gases.
- Advantages: High purification efficiency, thorough decomposition.
- Disadvantages: High costs, potential secondary pollution.
4. Water Absorption
- Principle: Dissolving water-soluble odors in water.
- Application: Water-soluble gases with organized emissions.
- Advantages: Simple and low-cost.
- Disadvantages: Low efficiency; requires secondary treatment.
5. Chemical Absorption
- Principle: Reaction of odors with chemical solutions.
- Application: High-volume, high-concentration odors.
- Advantages: Effective for specific gases; mature technology.
- Disadvantages: Low overall efficiency, high chemical usage.
6. Adsorption Method
- Principle: Transferring odors from gas to solid phase using adsorbents.
- Application: Low concentration, high purification needs.
- Advantages: Very high efficiency.
- Disadvantages: Expensive adsorbents, challenging regeneration.
7. Biofiltration
- Principle: Decomposition of odors by microorganisms on filter beds.
- Application: Widely used and mature technology.
- Advantages: Low-cost operation.
- Disadvantages: Large space, challenging maintenance.
8. Biotrickling Filtration
- Principle: Similar to biofiltration but uses inert materials.
- Application: Specific odor substances.
- Advantages: Stable operation, no material replacement needed.
- Disadvantages: Complex operation, requires nutrients.
9. Washing with Activated Sludge
- Principle: Absorbing and degrading odors in slurry with microorganisms.
- Application: Wide range, large gas volumes.
- Advantages: Compact, manageable.
- Disadvantages: High capital costs, complexity.
10. Aeration with Activated Sludge
- Principle: Dispersing odors in sludge with microorganisms.
- Application: Used in Japan for sewage treatment odor control.
- Advantages: High removal efficiency.
- Disadvantages: Limited by aeration intensity.
11. Multiphase Catalytic Oxidation
- Principle: Decomposing pollutants with catalysts.
- Application: High-volume, high-concentration gases.
- Advantages: Compact, low-cost.
- Disadvantages: Requires reagents.
12. Low-Temperature Plasma
- Principle: Using plasma-generated active particles to break down pollutants.
- Application: Effective for complex odors.
- Advantages: High versatility.
- Disadvantages: High initial costs.