The liquid used within a wet scrubber is typically recirculated through the system rather than continuously discharged after a single pass. As the scrubbing solution repeatedly comes into contact with contaminated air, it absorbs, neutralises or captures pollutants that have been removed from the gas stream.
Over time, this means the circulating liquid can accumulate dissolved salts, suspended solids, reaction products and other contaminants. A controlled proportion of the solution may therefore need to be removed and replaced with fresh liquid to maintain effective treatment conditions.
Exeon’s scrubX™ wet scrubber system continuously monitors and adjusts its scrubbing solution, with automated chemical dosing helping maintain the conditions required for effective pollutant removal.
Is Wet Scrubber Liquid Reused?
Yes. Recirculation is an important part of the wet scrubbing process.
Within scrubX™, the treatment liquid passes through the packed tower, where it comes into direct contact with contaminated air. Pollutants transfer from the gas stream into the liquid before the solution returns to the system reservoir and is recirculated.
Reusing the scrubbing liquid helps reduce unnecessary water and chemical consumption while maintaining continuous treatment.
However, the liquid cannot normally be recirculated indefinitely without some form of management. As contaminants and reaction products build up, they can affect the chemistry and performance of the solution.
What Is Wet Scrubber Blowdown?
Blowdown is the controlled removal of a proportion of the circulating scrubbing solution.
It is used to prevent excessive concentrations of salts, solids and captured pollutants from building up within the system. Fresh make-up water and, where required, treatment chemicals can then be introduced to maintain the appropriate operating conditions.
The amount and frequency of blowdown depends on factors including:
- Pollutant type and concentration
- Scrubbing chemistry
- Operating hours
- Water quality
- Rate of contaminant accumulation
- Required treatment performance
The liquid-management arrangement should therefore be considered when the wet scrubber is designed rather than treated as an afterthought.
What Happens to the Removed Liquid?
The appropriate handling method depends on what the scrubber has removed from the air.
Used liquid may contain dissolved contaminants, salts, suspended solids or products created by chemical neutralisation. Its composition should therefore be assessed before determining whether it can enter an existing site wastewater treatment process or requires separate treatment or disposal.
Sites handling chemical or industrial emissions may have different requirements from sewage, food processing or waste facilities.
Exeon designs industrial odour and emission control systems around the complete process, including the practical requirements associated with air treatment and system operation.
How Is the Scrubbing Liquid Kept Effective?
Maintaining the correct chemistry is essential. Parameters such as pH and reagent concentration influence how efficiently pollutants are absorbed or neutralised.
scrubX™ uses automated monitoring and chemical dosing to help keep the circulating solution within its intended operating range. This supports consistent treatment while avoiding unnecessary chemical addition.
Regular maintenance should also include inspecting pumps, sensors, dosing equipment, pipework and liquid levels to ensure the recirculation system continues operating correctly.
Where the emission stream requires another treatment stage, scrubX™ can also be combined with hi-flo™ activated carbon filtration as part of a multi-stage treatment arrangement.
Exeon’s wider range of industrial air filtration technologies allows the complete treatment process to be configured around the contaminants and operating conditions of each site.
Planning for recirculation, blowdown and appropriate handling of used scrubbing liquid from the outset helps ensure a wet scrubber remains effective, practical to operate and suitable for long-term industrial emission control.
Contact Exeon today to arrange a site consultation or request a tailored proposal. Our technical team will assess your airflow volumes and contaminant profile to design a system that delivers consistent emission control.