Specialists in the Control of Odors and Corrosion in Sewer Systems and Wastewater Treatment Plants.

TREATING ODORS

A variety of technologies are available to treat odorous air emitted from wastewater treatment plants, sludge handling facilities, and industrial processes. The selection of a particular technology or combination of technologies is dependent on factors such as:

• characteristics and strength of odorous air
• air flowrates
• contaminant loading patterns
• treatment objectives
• site characteristics
• operation and maintenance capabilities

The following table summarizes common technologies used to treat odorous air.

SUMMARY OF ODOROUS AIR TREATMENT ALTERNATIVES
Technique Frequency Of Use Cost Factors Advantages Disadvantages
Packed tower wet scrubbers High Moderate capital, high O&M cost Effective and reliable; long track record; small footprint High chemical consumption, high O&M
Activated carbon adsorbers High Cost-effectiveness depends on carbon replacement or regeneration frequency Simple; few moving parts; effective; several media options Applicable to relatively dilute air streams in order to ensure long carbon life
In-ground biofilters High Low to moderate capital; low O&M costs Simple; low O&M; effective; no chemicals Large footprint; design criteria varies; some failures due to short-circuiting, overloading
Pre-engineered biofilters Med Moderate to high capital; low O&M Low O&M, no chemicals; longer media life and smaller footprint than in-ground systems Higher capital costs than in-ground biofilters
Bioscrubbers, Biotrickling filters Med Moderate capital; low O&M Smaller footprint than biofilters, high H2S loadings possible; little or no chemicals Less efficient for non-H2S sulfur compounds
Thermal oxidizers Low Very high capital and O&M (energy) costs Effective for wide spectrum of odors and VOCs Only economical for high-strength, difficult to treat air streams
Diffusion into activated sludge basins Low Economical if use existing blowers or diffusers Simple; low O&M; effective, reliable Potential for corrosion of blower inlet components; pre-filtration of air stream required
Odor counteractants High Operating cost dependent on chemical usage Low capital cost Limited odor removal efficiency (<40%); only applicable for dilute air streams