Bio scrubbers are systems for the biological cleaning of exhaust air and exhaust gases and thus for the reduction of odours and polluting emissions. 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 bio scrubbers from Wessel-Umwelttechnik work almost without wastewater and are therefore very sustainable, regardless of the nature of the exhaust air. The basic requirement, however, is that the ingredients are water-soluble and bioavailable. Wessel-Umwelttechnik supplies turnkey plants like the Wessel BIOCAT-Scrubbers in single- and multi-stage construction.
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 closed-circuit water treatment system.
These plants are primarily used for water-soluble 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.
The BIOCAT-DUO-scrubber from Wessel-Umwelttechnik consists of two units. One unit is the already mentioned BIOCAT-scrubber. A second unit, the DLP (Dust Low Pressure) scrubber stage, is a cleaning stage for separating dust and fine fibres from the exhaust air. With the BIOCAT-DUO-scrubbers from Wessel, gaseous pollutants as well as dust can be removed from the exhaust air at the same time. The BIOCAT-DUO-scrubbers have two separate washing water circuits for this purpose. It is characterised by a compact design, as both units are housed in one column.
The BIOCAT-DUO-scrubbers are used in the wood-based panels industry, for example. More precisely: where MDF boards (medium density fibre) and moulded fibre parts are produced. Here the exhaust air contains fine wood fibres which have to be filtered out of the exhaust air. Furthermore, pollutants and odours must also be reduced.
Wessel continuously optimises its bio scrubber systems. This means, the legally required clean gas values can be safely maintained, now and in the future. The systems work efficiently, i.e. the efficiency of odour, pollutant and dust separation is high. The systems also meet all requirements for operational safety.
The BIOCAT bio-scrubbers from Wessel-Umwelttechnik require only very little maintenance and operating effort. It is, for example, not necessary to replace bio-filter material as with the BIOCAT bio-filters. Once installed, the system runs with low energy costs, among other things, thanks to low pressure losses in the entire system. The system is also easy to regulate if the exhaust air composition fluctuates.
Biological exhaust air cleaning systems in general and bio-scrubbers in particular are considered sustainable systems for exhaust air cleaning. Hardly any wastewater is produced in the process. Secondary emissions such as CO2, CO, NOx or dioxin do not occur with these purification systems. Waste heat is also not generated. The biomass produced during the cleaning process with the help of microorganisms and biocatalysts, which must be utilised, is low.
Bio scrubbers are used wherever exhaust air with volatile organic components and odorous substances are produced. For almost all industrial sectors and municipal applications, insofar as the pollutants contained in the exhaust air are water-soluble and non-toxic for the microorganisms added, bio scrubbers are an efficient and sustainable solution. These include: