The Importance of Polishing Media in Odor Control Systems
For wastewater treatment facilities, food waste operations, and even oil and gas applications, odor control is more than a nuisance — it’s a regulatory, operational, and community concern. One critical but often overlooked component in an effective air filtration system is polishing media: the final defense against trace-level gases that standard filtration can’t fully remove.
Why Polishing Media Matters
Many filtration systems are designed to target the most concentrated contaminants in a facility’s gas stream — most often hydrogen sulfide (H2S), mercaptans, and various volatile organic compounds (VOCs). These are handled by the primary media layers. But for operations requiring near-complete odor removal or sensitive instrumentation protection, polishing media is essential.
Polishing media is placed at the last pass of a multi-stage system, just before air is discharged. Its role is to capture residual gases that pass through the earlier layers — ensuring compliance with air quality standards and reducing the risk of community complaints or equipment corrosion.
Odor Control Challenges in Wastewater and Food Waste Facilities
Wastewater facilities face some of the most complex gas profiles, with sulfur compounds like H₂S and mercaptans being especially persistent. Even when the primary filtration media is effective, low-level gas breakthroughs can still occur.
Polishing media addresses these trace compounds and helps ensure total odor control. The same applies to food waste processing sites, which often deal with similar gas compositions and benefit from the same polishing strategies.
Common Polishing Media Types
CPS Blend and CPS 12 Blend
Among the most widely used polishing options are CPS Blend and CPS 12 Blend, both of which combine:
- Potassium permanganate-impregnated alumina (PureAir 8 is used in CPS Blend; PureAir 12 is used in CPS 12 Blend)
- Virgin bituminous activated carbon
This dual-function media offers both adsorption and chemical neutralization of sulfur-based gases, mercaptans, and VOCs. CPS 12 Blend provides a higher capacity and longer media life, making it ideal for higher concentrations or extended operating cycles.
These products are typically installed after the primary H2S-targeting media, polishing the remaining gas before final air discharge. Both meet UL certification requirements.
PureAir 8 and PureAir 12
PureAir 8 and PureAir 12 are high-performance polishing medias engineered to target sulfur-based gases, including hydrogen sulfide, mercaptans, and VOCs. Both are made from potassium permanganate-impregnated activated alumina, offering strong oxidative capacity and reliable performance in a wide range of applications.
PureAir 12 features approximately 50% greater adsorption capacity than PureAir 8, making it a strong choice for systems with higher contaminant loads or longer changeout cycles. These medias can be used on their own or in conjunction with other layers depending on system design and gas profile.
While CPS Blend and CPS 12 Blend are often selected as the default polishing solution in wastewater and food waste applications due to their blended formulation, PureAir 8 and 12 remain essential tools in our product lineup. They provide proven effectiveness, media flexibility, and UL-certified performance across a wide variety of odor control and corrosion prevention needs.
Applications Beyond Wastewater
Polishing media also plays a critical role in the oil and gas industry, particularly in protecting sensitive electronics and instrumentation. Even trace concentrations of corrosive gases can damage circuit boards and sensors. A final polishing stage helps prevent this, extending equipment lifespan and reducing maintenance costs.
A Tailored Approach to Clean Air
Polishing media isn’t one-size-fits-all. System design, gas loading conditions, and application type all influence the right media choice. Whether you need CPS 12 for high-performance sulfur compound removal or a custom blend using PureAir media, PureAir Filtration can help design a solution that fits your exact needs.
Get a Customized Recommendation
Need help identifying the best polishing media for your application? Contact our team to discuss your system and ensure complete protection — from the first pass to the last.
