Air pollutant exhausters - Import export

The BIOCATDUOscrubber from WesselUmwelttechnik consists of two units. One unit is the already mentioned BIOCATscrubber. 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 BIOCATDUOscrubbers from Wessel, gaseous pollutants as well as dust can be removed from the exhaust air at the same time. The BIOCATDUOscrubbers have two separate washing water circuits for this purpose. It is characterised by a compact design, as both units are housed in one column. COMMON USE CASES The BIOCATDUOscrubbers are used in the woodbased 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.

Adsorption plants are an efficient way of filtering VOC (volatile organic compounds) or other pollutants from exhaust air, flue and exhaust gases in industrial and municipal applications. In comparison to absorption processes, in which harmful substances are bound by the use of liquids, an adsorption plant concentrates the pollutants These are physically attached to an adsorbent such as zeolite or activated carbon. The adsorption process is efficient and costeffective, especially for low to medium pollutant concentrations in large volume flows. If necessary, concentrated solvents, for example, can be recovered and reused with the help of other technologies. Especially for exhaust air streams with low or medium concentrations of VOC and other harmful exhaust gases, the use of socalled VOC concentrators is of great advantage.

Industrial air scrubbers are used to purify the exhaust air of pollutants, for example in the chemical or pharmaceutical industry. As soon as the exhaust air meets the legal requirements for clean gas values, it can be returned to the environment. Absorptive exhaust air purification by waste gas scrubbers is a frequently used technology. Gas scrubbers are suitable for removing pollutants, aerosols and dust from the exhaust air. Especially watersoluble exhaust air components are separated with high efficiency.

Biological exhaust air cleaning is used whenever exhaust air has to be cleaned from volatile organic compounds (VOCs) and odours. Biofilters play a major role in this process. The polluted exhaust air is passed through a filter medium where the VOCs and odours are separated. Normally, this medium is an organic carrier material where microorganisms are grown on. They convert the VOCs and odours into noncritical components by means of their metabolism. Especially regarding the removal of odorous substances, biofilters are a very efficient and comparatively inexpensive way of biofiltration with an efficiency of up to 99 %. BIOCATbiofilters have a high degree of efficiency in a wide range of applications, even for exhaust air components that are difficult to dissolve in water.

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.