The Removal of Hydrogen Sulfide from Biogas in a Microaerobic Biotrickling Filter Using Polypropylene Carrier as Packing Material

Biological removal of hydrogen sulfide in biogas is an increasingly adopted alternative to the conventional physicochemical processes, because of its economic and environmental benefits. In this study, a microaerobic biofiltration system packed with polypropylene carrier was used to investigate the removal of high concentrations of H2S contained in biogas from an anaerobic digester. The results show that H2S in biogas was removed completely under different inlet concentrations of H2S from 2065 +/- 234 to 7818 +/- 131 ppmv, and the elimination capacity of H2S in the filter achieved about 122 g H2S/m(3)/h. It was observed that the content of CH4 in biogas increased after the biogas biodesulfurization process, which was beneficial for the further utilization of biogas. The elemental sulfur and sulfate were the main sulfur species of H2S degradation, and elemental sulfur was dominant (about 80 %) under high inlet H2S concentration. The results of terminal restriction fragment length polymorphism (T-RFLP) and fluorescence in situ hybridization (FISH) show that the population of sulfide-oxidizing bacteria (SOB) species in the filter changed with different concentrations of H2S. The microaerobic biofiltration system allows the potential use of biogas and the recovery of elemental sulfur resource simultaneously.