Also known as trickling filters and biotrickling filters, biological scrubbers or bioscrubbers use a modified form of packed tower technology. A special packing is used that encourages and allows the growth of a highly active biological medium on the packing surface. The packing and biological medium are irrigated with water. The pollutants in the gas stream are absorbed into the water and aerobically degraded by the biological medium. The technology is applicable to most odour control and many VOC emissions control applications, such as sewage treatment works, pump stations, rendering plants, food plants and the like.
The technology provides the following advantages:
- High efficiency gas absorption, to over 99% on hydrogen sulphide if required
- Minimized chemical consumption- very low operating costs compared with chemical scrubbers
- Robust technology, able to handle widely varying inlet loads
- The packing is inert and does not degrade over time
- Chemical scrubbers can be readily converted to biological scrubbers to reduce operating costs