Nimas M. S. Sunyoto1, 2, Warin Rukruem3, Benjaphon Suraraksa4, and Pawinee Chaiprasert1
The removal of hydrogen sulfide in biogas is imperatively required as it lead the corrosion to the engines and pipe lines when it is used as biofuel (1). Biofilter was broadly used as an alternative on hydrogen sulfide removal. The common bacteria used in the H2S removal including Thiobacillus sp., Beggiota sp., and Pseudomonas sp (2). However, the utilization of mix culture seemed to be more favourable in the field application. This study investigated the role of Sulfide oxidizing bacteria (SOB) to be used as converting agent in high strength H2S removal. The study used three different particle sizes of packing material namely RHAB of 0.5-1.0 cm (RHAB type 1), 1.5-2.0 cm (RHAB type 2) and 2.0-3.5 cm (RHAB type 3). The operation was carried out in 5 litres working volume biofilter under controlled dissolved oxygen (DO) 0.5 mg.l-1 and pH 7 and employed mix culture seed sludge taken from open pond of swine manure wastewater treatment. The synthetic hydrogen sulfide gas in high strength of H2S (3,000 ppm) was fed in upflow direction at various flow rate. H2S loading rate (SLR) at 0.17 and 0.25 l.min-1 was used at the 30 and 20 minutes of GRT resulting in H2S loading rate of 8.18 and 12.27 g H2S.m-3.h-1, respectively. The role of SOB in term of H2S removal efficiency, bacterial activity and metabolic products produced under high strength of inlet H2S was investigated. The average of removal efficiency of RHAB type 1, 2 and 3 was in the range of 97,8-99,6% at GRT 30 minutes and 91,3-94,8% at GRT 20 minutes. In addition, the study of bacterial activity showed that the avarage bacterial activity was 8.6-12.63 g Na2S2O3.g VSS-1.day-1. Moreover it was found that the activity of SOB had converted the H2S into S0 form up to 81,1%.
Keywords: H2S removal, biogas, biofilter
- Fischer, M. E., et al., Biogas purification : H2S removal using biofiltration. Waterloo University, Ontario, Canada, 1-138 (2010)
- Pipatmanomai, S., et al., Economic assessment of biogas-to-electricity generation system with H2S removal by activated carbon in small pig farm. Applied Energy, 86, 669–674 (2008)
*)This abstract was originally presented at 5th Young Scientist Seminar at Yamaguchi Seminar Park, Yamaguchi, Japan, November 22-23th 2011