Afras Air

Biological Odor Control

Bio-Trickling Filter

Odors emitted by sewage treatment and manufacturing waste are typically an indication of an anaerobic or "septic" condition. Early stages of processing will tend to produce foul smelling gases, with hydrogen sulfide being most common in generating complaints. Large process plants in urban areas will often treat the odors with carbon reactors, a contact media with bio-slimes, small doses of chlorine, or circulating fluids to biologically capture and metabolize the noxious gases. Other methods of odor control exist, including addition of iron salts, hydrogen peroxide, calcium nitrate, etc. to manage hydrogen sulfide levels.


Our Biofilteration System uses micro organisms fixed to porous organic media to break down pollutants present in an air stream.  The micro organisms grow in our Biofilter on surface of media particles.  The filter-bed media consists of relatively inert substances (wood chips, compost, bark) which ensure large surface attachment area and additional nutrient supply. This technology requires longer Empty Bed Residence Time (EBRT) compared to Bio-Trickling Filter, and as the result requires larger foot-print.

Our Biofilters are most suitable for an air stream with lower H2S but higher VOC concentration.

Carbon Vessels Odor Control

Carbon Scrubber Odor Control - Available Standards 5000 and 10,000 (Custom Design up to 100,000)

 Industrial and municipal odors are often detectable below 1 ppm of Hydrogen Sulfide (H2S) and Volatile Organic Compounds  (VOCs), so  odor control scrubbers are engineered to function at 98-99% efficiencies and higher for true, “zero odor” performance.

 Afrasenvo scrubbers are ideal for continuous, automatic odor control. Gas volume is not limited, but generally ranges from 35 cfm to 150,000 cfm. Where the gas stream contains corrosives, provides a single scrubber for scrubbingcorrosives and odors.

This technology neutralizes corrosive fumes while using minimal water and energy and yielding a clean stack. Afrasenvo Odor control systems operate in the 99%+ efficiency range and are effective for a broad range of contaminants. 

Scrubber Design

Depending on odor composition Afrasenvo  scrubbers have 2-3 independent stages. Mercaptins and amines are best handled with wet scrubber sections. Sulphur and other compositions may require consecutive treatment stages, including acid, caustic and oxidation stages.