At Air Technology Systems, we have a number of Solutions catered to resolving your Odour Control issues with the highest levels of efficiency.
Carbon Filters
Industrial carbon filters use adsorption onto carbon media to treat odours.
Different chemical impregnations into the carbon can increase the capacity for adsorption for specific chemicals.
Due to the method of treatment, once a set amount of contaminant has adsorbed onto the media, the media is then spent and cannot hold any more media.
However, if the media has capacity for adsorption, they are incredibly efficient regardless of the concentration of contaminant in the air stream.
Different Approaches
Industrial carbon filters are therefore used as either single stage treatment for low odour sources, single stage treatment for sources with fluctuating / infrequent odour loads, or final polishing stages for larger Odour Control Systems.
Media Replacement
Once the carbon is spent, you will need to arrange a media replacement.
This involves the removing of the media, usually using a vacuum bagging unit, which extracts the media out directly into a skip, or self-contained vessel.
It can then be removed from site and often disposed of as non-hazardous waste or re-generated and recycled.
Depending on the contaminants that you have been treating, this may be subject to hazardous waste disposal. This can be checked at the point of disposal. New media must then be reloaded into the vessel.
Biofilters
Biofilter Odour Control uses a biological process to treat odours in the air.
Essentially, the biofilter media, kept damp via an irrigation system, provides a base for a bug population to grow on once food is provided, in the form of airflow, into the biofilter.
This is a very low-cost solution to operate, only requiring the electricity to run the fan(s) and the intermittent irrigation system to maintain the feed.
Biofilters have several constraints that lead to them not being suitable for every application.
Challenges
Firstly, as they are maintaining a population of bugs to feed off the odour, they are only suitable for constant odour loads.
Additionally, only a single population of bugs can grow on one biofilter.
In this scenario, you can either use two biofilters in series, with the first treating the highest odour load and the second picking up the contaminant that bypassed stage 1.
An alternative is to use a chemical scrubber to treat one of the compounds and then a biofilter for the other.
Chemical Scrubbers
Chemical scrubbers, also known as Wet Scrubbers, typically have a far smaller footprint than a biofilter for the same airflow.
Along with the scrubber tower, you will also require chemical storage, chemical dosing pumps and cabinet, recirculation pumps, softened water, and various instrumentation to control the system.
Therefore, the overall footprint of a scrubber system is still reasonably large, although it can be much more easily fitted into constrained areas being made up from several small plant items.
Challenges
Where the biofilter only required occasional water, the scrubber is constantly running, regularly emptying and refilling, and always adjusting to the inlet load detected.
This means that the operational costs of a scrubber system are high compared to the other systems, but they are incredible at treating a huge variety of odours at ever changing concentrations.
Ammonia
Where ammonia is a concern on sites, we can use a Chemical Scrubber as a first stage of treatment, with the added benefit of it being able to pre-humidify air.
At levels up to 5ppm, water as a scrubbing medium alone is very effective at removing ammonia from air.
If over time the ammonia levels increase, this has the additional benefit of being ready to easily modify to an acid dosing scrubber to treat higher loads.
Fans
Odour control systems are typically high-pressure systems, and therefore usually require centrifugal fans. Often, they are within explosive atmospheres too, so Air Technology Systems and our suppliers are experienced in working with a range of equipment suitable for ATEX, corrosive, or otherwise aggressive atmospheres.