Fixed Film Biotreatment Systems

Most biological air treatment technologies are fixed-film systems that rely on the growth of a biofilm layer on an inert organic support such as compost or peat (biofilters) or on an inorganic support such as ceramic or plastic (biotrickling filters). For both systems, solid particles must be removed from waste gases before the gases enter the system; particulates plug the pores. Both systems are best suited for treating vapor streams containing one or two major compounds. When properly designed, biofilters are well suited for treating streams that vary in concentration from minute to minute.

Adsorption of ammonia (NH3), hydrogen sulfide (H2S), and other odors on the soil particle surface.

Adsorption of ammonia (NH3), hydrogen sulfide (H2S), and other odors on the soil particle surface.

REGENERATION REACTIONS Odorous hydrogen sulfide is oxidized to odorless sulfate H2S + 2O2 ® SO42- + 2H+ Ammonia is dissolved in water and oxidized to odorless nitrate NH3 + H2O ® NH4+ + OH2-2NH4+ + 3O2 ® 2 NO3- + 8H+ Bacteria oxidize odorous volatile organics to odorless carbon dioxide and water volatile organics + O2 ® CO2 + H2O

REGENERATION REACTIONS Odorous hydrogen sulfide is oxidized to odorless sulfate H2S + 2O2 ® SO42- + 2H+ Ammonia is dissolved in water and oxidized to odorless nitrate NH3 + H2O ® NH4+ + OH2-2NH4+ + 3O2 ® 2 NO3- + 8H+ Bacteria oxidize odorous volatile organics to odorless carbon dioxide and water volatile organics + O2 ® CO2 + H2O

FIG. 5.22.2 Adsorption of odors and regeneration of active sites.

0 0

Post a comment