Chemical scrubbers remove odorous substances from a gas stream. They do this by dissolving the odorous emissions or absorbing them into the scrubbing media. The scrubbing media is usually a liquid, but can also be:
- a slurry
- a powder – for example, a dry scrubber.
Use chemical scrubbers to pre-treat odour emissions to:
- adjust the pH
- adjust the moisture
- reduce concentrations of acid gases, ammonia or other chemicals.
Treat the remaining odour by using another control, such as a biofilter or activated carbon filter.
Type of control
- Chemical
When to use chemical scrubbing
A chemical scrubber is a popular method to reduce odour. It's used in a variety of industries that produce fumes and gases.
Chemical scrubbers are suitable for controlling:
- ammonia
- chlorine
- sulphur
- carbon dioxide
- highly acidic gases, including fluoride.
Chemical scrubbing can also remove mercury.
Industries use a chemical scrubber for:
- chemical processes
- metal finishing
- sewage treatment
- other industrial applications where fumes and gases need to be controlled.
Considerations and requirements
There are different chemical scrubbing options. To choose the best solution, consider your circumstances:
- what types of odour are generated
- how concentrated the odour emissions are
- temperature of the fumes or gases produced
- the pH of the gas stream (acid gases <7 or ammonia >7)
- the efficiency rate that the chemical scrubber needs.
Determine the efficiency rate by accounting for the factors above as well as your other odour treatment or pre-treatment methods.
A qualified professional can help you select the best type of chemical scrubber for your business. Visit Work with a consultant.
Make sure there's appropriate contact time between the odour emissions and the scrubbing media. This achieves optimal removal of odour. The length of time depends on your circumstances and the type of scrubber you select.
You must maintain your chemical scrubber once it is installed. Harmful microorganisms grow in poorly maintained chemical scrubbers. Replace or refresh the scrubbing media often. How often you refresh or replace the scrubbing media depends upon:
- what chemical scrubber you implement
- the concentration of odour emissions in the gas stream
- the gas stream flow rate.
In some instances, scrubbing media may need changing daily.
Reuse or dispose of the scrubbing media safely when you replace it. Chemical scrubbing removes odour from the gas stream. However, it does not eliminate odour particles. Instead, the particles become trapped within the scrubbing media.
There are waste duties and obligations that you must meet when reusing or disposing of chemical scrubbing media.
For safety information, check with your supplier, and refer to the WorkSafe Australia guidance Safe handling of industrial waste: A practical guide for workplaces(opens in a new window).
For more information on requirements for managing odour, visit Control odour from your business.
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