Sulfide Oxidizing Bacteria (SOB) Role in Biofilter to Remove High Strength Hydrogen Sulfide From Biogas

Nimas M. S. Sunyoto^{1, 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

 

References:

1. Fischer, M. E., et al., Biogas purification : H₂S removal using biofiltration. Waterloo University, Ontario, Canada, 1-138   (2010)
2. 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

Endophytic Fungi Isolated from Mangrove (Rhyzopora mucronata) and Its Antibacterial Activity on Staphylococcus aureus and Escherichia coli

A. A. Prihanto, M. Firdaus and R. Nurdiani
Dept. Fishery Product Technology, Faculty of Fisheries and Marine Science, Brawijaya University, Veteran street, Malang, Indonesia
Abstract: Disc diffusion method was used to investigate the antibacterial activity of methanol extract of five endophytic fungi isolated from mangrove (Rhizopora mucronata) on Staphylococcus aureus ATCC 9144 andEscherichia coli ATCC 8739. Fungi were isolated from leaf, stem and root of R. mucronata. Potato dextrose agar and potato dextrose broth were used for fungi purification and fermentation. Fungal metabolites were extracted with methanol (1:1 v/v) for 24 h before vacuum evaporated to yield the crude extracts. Antimicrobial activity test was done according to the Kirby-Bauer test. The inhibition zone around each disc was considered to measure antibacterial activity of endophytic fungi. Only three endophytic fungi showed inhibition activity on S. aureus ATCC 9144 and two endophytic fungi showed inhibition on E. coli ATCC 8739. The results suggested that the extracts have a high potential for enteric diseases treatment caused by foodborne pathogen.

Key words: Antibacterial, endophytic fungi, mangrove, Rhyzopora mucronata.
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