Removal of hydrogen sulfide in biogas from wastewater treatment sludge by real-scale biotrickling filtration desulfurization process

Abstract

The biological removal of hydrogen sulfide in biogas is an increasingly adopted alternative to conventional physicochemical processes because of its economic and environmental benefits. In this study, a real-scale biotrickling filtration (BTF) process packed with polypropylene carrier was used to investigate the removal of high concentrations of H2S in biogas from an anaerobic digester. The results show that H2S in biogas was entirely removed under different inlet concentrations of H2S from 2,923 to 4,400 ppmv, and the elimination capacity of H2S in the filter achieved about 52.71 g H2S/m3/h). In addition, the process efficiency was found to be independent of the inlet H2S concentration. The removal of high concentrations of H2S in biogas was accomplished by the BTF process with SOB (Acidithiobacillus thiooxidans), which is active in the acidic environment (pH 1.5–3.5). In addition, the process efficiency was found to be independent of the inlet H2S concentration. Consequently, a real-scale BTF process allowed the potential use of biogas and the recovery of elemental sulfur resources simultaneously. HIGHLIGHTS H2S in biogas produced from WWT sludge was removed by a real-scale BTF plant.; The process efficiency was found to be independent of inlet H2S concentration.; The elimination capacity of the system reached a maximum of value.; The real-scale BTF unit was found to provide sufficient removal efficiency for H2S in the biogas.;

Keywords

• anaerobic sludge digester
• biogas
• biological desulfurization
• biotrickling filter
• removal of hydrogen sulphide