Microbial Biotechnology

Environmental Biotechnology

Electronic Journal of Biotechnology ISSN: 0717-3458 Vol. 11 No. 2, Issue of April 15, 2008
© 2008 by Pontificia Universidad Católica de Valparaíso -- Chile Received June 19, 2007 / Accepted December 6, 2007
DOI: 10.2225/vol11-issue2-fulltext-13

Selection of sulfur oxidizing bacterium for sulfide removal in sulfate rich wastewater to enhance biogas production

Duangporn Kantachote*
Department of Microbiology
Faculty of Science
Prince of Songkla University
Hat-Yai 90112, Thailand
Tel: 66 74 288310
Fax: 66 74 446661
E-mail: duangporn.k@psu.ac.th

Wilawan Charernjiratrakul
Department of Microbiology
Faculty of Science
Prince of Songkla University
Hat-Yai 90112, Thailand
Tel: 66 74 288324
Fax: 66 74 446661
E-mail: wilawan.c@psu.ac.th

Napavarn Noparatnaraporn
Department of Microbiology
Faculty of Science
Kasetsart University
Bangkok 10900, Thailand
Tel: 662 579 4956
Fax: 662 5797546
E-mail: fscinvn@ku.ac.th

Kohei Oda
Department of Applied Biology
Faculty of Textile Science
Kyoto Institute of Technology
Kyoto, Japan
Tel: 81 75 7247775
Fax: 81 75 7247760
E-mail: bika@kit.ac.jp

Web site: http://www.psu.ac.th

*Corresponding author

Financial support: This work was supported by the National Research Council of Thailand (NRCT) and Japan Society for the Promotion of Science (JSPS).

Keywords: biodesulfurization, biogas, effluent from a sulfate reduction reactor, sulfide.


BOD: biochemical oxygen demand
COD: chemical oxygen demand
DS: dissolved sulfide
H2S: hydrogen sulfide
MSM: mineral salts medium
MPB: methane producing bacteria
ROW: raw optimized wastewater
SOB: sulfur oxidizing bacteria
SOW: sterile optimized wastewater
SRB: sulfate reducing bacteria
SRR: a sulfate reduction reactor
SEM: scanning electron microscope
TKN: total Kjeldahl nitrogen
TS: total sulfide
TSY: thiosulfate yeast extract medium
UASB: upflow anaerobic sludge blanket
VFAs: volatile fatty acids

Abstract   Full Text

Sulfur oxidizing bacteria (SOB) were isolated and tested in order to remove sulfide from high sulfate wastewater to reduce the amount of hydrogen sulfide (H2S) in the produced biogas. A promising SOB isolate, designated as isolate T307, was selected due to its best sulfide removal (86.7%) in the effluent of a sulfate reduction reactor (SRR) over a 24 hrs incubation. The bacterium was able to grow better as a mixotroph (yeast extract as a carbon source) than as a chemolithoautotroph. In addition, as a heterotroph, the bacterium grew well with yeast extract and peptone. Based on partial 16S rRNA gene sequence, the isolated T307 was an Alcaligenes sp. and was able to convert most of sulfide species (total sulfide: TS; dissolved sulfide: DS and H2S) into elemental sulfur or sulfate over a 20 hrs period of cultivation by controlling the speed of shaking. In a biogas reactor set, after pre-treating a sulfide medium with Alcaligenes sp. T307 there was a much higher specific yield of CH4 (238 ml CH4 g-1COD removed) and more biogas (154 ml L-1 d-1) was produced with the biogas containing more methane (48.1% CH4, 51.5% CO2 and 0.41% H2S) in comparison to a control with a specific yield of CH4, (72 ml CH4 g-1COD removed) 86 ml L-1 d-1 biogas produced with a composition of 35.5% CH4, 63.7% CO2 and 0.86% H2S.

Supported by UNESCO / MIRCEN network