Part B: Advances in gas emission control techniques for anaerobic-based STPs Technical Note 5 – Biofiltration systems for waste gas treatment

Abstract

Nos efluentes de reatores anaeróbios estão presentes gases produzidos durante o processo de tratamento (e.g. CH4 and H2 S). The techniques for controlling the emissions of the gases presented in this collection of Technical Notes (TNs) are based on the principle of desorption of the dissolved gases in effluent, through their transfer to the gaseous phase. The resulting gas, called waste gas, must be properly managed, for example, by means of its destruction/oxidation in biofilters or biotrickling filters. These biofiltration techniques can also be used to treat the waste gas generated in confined areas for odor and corrosion control in the sewage treatment plants (STPs). In this sense, the present TN seeks to contribute to the knowledge of the H2 S and CH4 treatment process through biofiltration. The necessary conditions for the biofiltration of H2 S and CH4 are quite different, reaching H2 S removal efficiencies between 90% and 100% for detention times between 1 and 2 min, and CH4 removal efficiencies between 70% and 100% for much longer detention times, between 20 and 30 min, considering the use of sequential bioreactor systems.