When do you have to consider about Alternatives?
The biological degradability of pollutants is a precondition for the proper function of a biofilter. This precondition is usually fulfilled for all volatile organic compounds especially odourous compounds. Hydrogensulfide and ammonia are very good degradable.
Not or very slow biological degradable volatile pollutants
Organic cyan-compounds are not or very slow degradable by bacteria as well as halogenated compounds. For these kind of pollutants activated carbon filters could be used because any thermic degradation of these compounds would only create another pollutant.
Very high concentration of pollutants
|If the concentrations of pollutants are very high (>5g/m³ waste air) other treatments could be more economic because high pollutant concentrations require adequate large biofilter plants. In any case a comparative calculation for a biofilter and an alternative methode should be done in order to get a good basis for investment decision.|