Nitrate-reducing, sulfide-oxidizing bacteria as microbial oxidants for rapid biological sulfide removal |
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Authors: | Bart De Gusseme Peter De Schryver Michaël De Cooman Kim Verbeken Pascal Boeckx Willy Verstraete & Nico Boon |
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Institution: | Laboratory of Microbial Ecology and Technology (LabMET), Ghent University, Ghent, Belgium;;Department of Metallurgy and Materials Science, Ghent University, Ghent, Belgium;and;Laboratory of Applied Physical Chemistry (ISOFYS), Ghent University, Ghent, Belgium |
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Abstract: | The emission of hydrogen sulfide into the atmosphere of sewer systems induces the biological production of sulfuric acid, causing severe concrete corrosion. As a possible preventive solution, a microbial consortium of nitrate-reducing, sulfide-oxidizing bacteria (NR-SOB) was enriched in a continuously stirred tank reactor in order to develop a biological technique for the removal of dissolved sulfide. The consortium, dominated by Arcobacter sp., was capable of removing 99% of sulfide. Stable isotope fractioning of the sulfide indicated that the oxidation was a biological process. The capacity of the NR-SOB consortium for rapid removal of sulfide was demonstrated by using it as an inoculum in synthetic and real sewage. Removal rates up to 52 mg sulfide-S g VSS?1 h?1 were achieved, to our knowledge the highest removal rate reported so far for freshwater species in the absence of molecular oxygen. Further long-term incubation experiments revealed the capacity of the bacteria to oxidize sulfide without the presence of nitrate, suggesting that an oxidized redox reserve is present in the culture. |
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Keywords: | microbially induced concrete corrosion (MICC) sulfate reduction H2S production biologically produced sulfur nitrate reduction electron sink |
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