Exhaust filters - Import export

A bio scrubber combines physical scrubbers with a biological activation unit. In this process, air polluted with a wide variety of pollutants is cleaned with the aid of a washing liquid which is loaded with microorganisms and biocatalysts (various enzymes) taken from nature. The washing water absorbs the exhaust air and pollutants from the air. Subsequently, added microorganisms oxidise them. These microorganisms use the air pollutants as substrate and nutrient medium and convert them into naturally formed decomposition products such as CO2, water, and biomass. Here, the washing water is continuously regenerated and used in a closedcircuit water treatment system. TYPICAL APPLICATION AREAS These plants are primarily used for watersoluble ingredients of the exhaust air. The usual pollutants that are filtered from the exhaust air with the help of bio scrubbers include aldehydes such as formaldehyde, alcohols, ketones and other hydrocarbon compounds.

When it comes to filter material, there are a few points to consider. The filter material should have a large surface area. This ensures a good exchange rate between exhaust air and filter material and provides sufficient space for microorganisms to colonise. The filter material must be designed in such a way that it has a good water holding capacity. The colonised microorganisms are only viable in a moist environment. In general, different filter materials are used in one batch. The reason for this it ensures both a good stability of the filter bed and a larger surface. In addition, the added microorganisms must be sufficiently supplied with inorganic nutrients and trace elements, unless this is provided by the composition of the exhaust air. The temperature inside the biofilter system plays a decisive role as well. Temperatures between 5 °C and 40 °C are favourable for the microorganisms to work properly.