There are three main biological processes that can occur in a biofilter, (i) attachment of microorganism, (ii) growth of microorganism
and (iii) decay and detachment of microorganisms. As the success
of a biofilter depends on the growth and maintenance of microorganisms (biomass) on the surface of filter media, it is necessary to
understand the mechanisms of attachment, growth and detachment
on the surface of the filter media.