Biological waste gas purification - Biofilters
|Publication Date:||1 March 2016|
|ICS Code (Other standards related to air quality):||13.040.99|
This standard covers the biological treatment of waste gas/exhaust air streams for the control of gase ous pollutant, aerosol and notably odorant emissions. Biodegradation of the air pollutants is accomplished under aerobic conditions by microorganisms colonising on solid support media. This treatment technology is referred to as biofiltration, the associated systems as biofilters.
The standard provides an overview of waste gas streams that have been successfully treated and/or pollutants that have been effectively degraded in biofilter systems. It addresses the criteria to be considered for the proper design of the biofilter system, discusses performance evaluation criteria and presents production processes in which biofilters have become successfully established for waste gas treatment.
Note: In the following description, the gaseous process effluents to be treated are mainly referred to as waste gas. Depending on the application, the term "waste gas" may therefore also relate to exhaust air.
Gas volumes and flows indicated normally relate to standard temperature and pressure conditions. Exceptions are the surface and volumetric loading rates of the biofilter where the associated volumetric gas flow rates relate to the actual operating conditions.
Where applicable, reference is made to the statutory regulations and technical rules to be observed.
This standard describes the state of the art in biofiltration technology for biological waste gas treatment. Regardless of the numerous practical applications of biofilters, the applicability of biofiltration to the specific waste gas stream should be confirmed by field pilot studies in all cases where no application-specific
Biofilters have become successfully established in the applications listed in Table 1 (see VDI 2590 and [1 to 4]). This list does not make any claims to completeness with regard to the components there listed for the individual applications.
Table 2 shows the individual substances and substance groups for which biodegradation results are available from biofiltration tests.
Note: Depending on the specific waste gas composition, the individual substances may exhibit a biodegradation behaviour differing from that in Table 2.
It should be noted that the list is based on experience available so far (e. g. as per [5 to 7]) and that there are no clear cut-off points between the individual categories. Table 2 may serve as a decision-making basis to determine whether prior treatability tests in a biofilter pilot plant will be needed (see Section 6.3).