Dissolved pollutants in waters or pollutants in process airstreams can be adsorbed to different types of solid materials in fixed beds. When a certain amount is adsorbed the bed does not have the ability to take up more way a breakthrough occurs and the pollutants will pass through the bed. Exchange or regenerating of the adsorbent must be done.
There are various types of adsorptions systems:
- Beds of one time use where the adsorbent is replaced and destructed
- Regeneration of the bed at site with steam or heated gas and the adsorbed substances are condensed or combusted
- The adsorbent is taken to other site for regeneration or reactivating.
The adsorbent can be of various types depending on pollutant and application. For example, active carbon, synthetic zeolites or polymer materials can be used but also natural materials like peat can be used.
Advantages
- Relatively uncomplicated equipment
- Relatively low pressure drop
- Minor problems with waste products and waste waters from the regeneration
Applications
- Toxic- or colour – matters in waste waters
- VOC and bad smelling substances in different types of process – and ventilation air
