Sewage smell from a wastewater treatment plant is usually caused by hydrogen sulfide, ammonia, mercaptans, organic sulfur compounds, and volatile organic compounds released from inlet works, equalization tanks, sludge areas, anaerobic zones, and pumping stations. A reliable solution normally combines source enclosure, negative-pressure collection, and a treatment system such as low-temperature plasma, microwave ultraviolet oxidation, chemical scrubbing, activated carbon adsorption, or biological deodorization.
The right process depends on odor concentration, air volume, humidity, corrosion risk, discharge limits, and whether the odor contains high levels of H2S or mixed VOCs.
Main odor sources in wastewater plants
Common odor points include:
- Inlet pumping stations and coarse screens
- Grit chambers and primary treatment areas
- Equalization tanks and anaerobic tanks
- Sludge thickening, dewatering, and storage rooms
- Leachate collection points
- Covered channels and wet wells
In most plants, the problem is not only one source. Odor spreads because gases escape from several open or poorly sealed locations at the same time.
Recommended treatment process
For stable odor control, the usual engineering sequence is:
- Cover the odor source with FRP, stainless steel, or corrosion-resistant covers.
- Keep the covered area under slight negative pressure.
- Collect the gas through corrosion-resistant ducts.
- Pretreat high humidity, dust, or acid mist when necessary.
- Treat the collected gas with the selected deodorization equipment.
- Discharge through a stack after meeting the required standard.
Equipment selection guide
| Odor condition | Recommended process | Notes |
|---|---|---|
| Low to medium concentration mixed odor | Low-temperature plasma equipment | Good for H2S, ammonia, mercaptans, and low-concentration VOC odor |
| Wastewater stations with strong organic odor | Microwave UV oxidation equipment | Suitable for odor oxidation and photolysis of complex gas |
| High H2S concentration | Chemical scrubber + polishing unit | Scrubbing reduces acid gas load before final treatment |
| Low concentration, intermittent odor | Activated carbon adsorption | Useful as polishing or backup treatment |
| Large stable biological odor load | Biofilter or bioscrubber | Requires space and stable operating conditions |
When low-temperature plasma is suitable
Low-temperature plasma is useful when the plant needs compact equipment, fast start-up, and treatment for mixed odor components. It can be used for sewage stations, sludge rooms, garbage leachate odor, and industrial wastewater odor.
Related equipment: Low Temperature Plasma Equipment
When microwave UV oxidation is suitable
Microwave UV oxidation is suitable for wastewater odor that contains mixed organic compounds, sulfur odor, and odor from garbage or sludge treatment areas. It is often selected when the project needs oxidation instead of only adsorption.
Related equipment: Microwave Ultraviolet Oxidation Equipment
FAQ
What is the best way to remove sewage smell?
The best method is to enclose the odor source, collect the gas under negative pressure, and treat it with equipment matched to the gas composition. Equipment alone is less effective if the odor source is not sealed and collected.
Can activated carbon remove sewage smell?
Activated carbon can remove low-concentration odor and VOCs, but it may saturate quickly when H2S, humidity, or high organic load is present. It is often better as a polishing stage.
Is plasma equipment suitable for wastewater odor?
Yes. Low-temperature plasma can treat many low to medium concentration wastewater odor gases, especially when combined with good collection design.
How do you control H2S odor in sewage plants?
High H2S odor is usually controlled with source covering, chemical scrubbing, oxidation equipment, and corrosion-resistant ducting.
