Thermophilic sulphate and sulphite reduction in lab-scale gas-lift reactors using H2 and CO2 as energy and carbon source

Abstract

Feasibility of thermophilic (55°C) sulphate and sulphite reduction with H2 and CO2 gas‐mixtures was studied in gas‐lift reactors, which contained pumice particles as carrier material. Particular attention was paid to biomass retention and the competition between hydrogenotrophic sulphate‐reducers and other hydrogenotrophic thermophiles. A model medium with defined mineral nutrients was used. The results of the experiments clearly demonstrate that sulphate conversion rates up to 7.5 g SO42−/L per day can be achieved. With sulphite, a reduction rate of 3.7 g S/L per day was obtained, which equals a sulphate conversion rate of 11.1 g SO42−/L per day. Under the applied conditions, a strong competition for hydrogen between hydrogenotrophic sulphate‐reducers, tentatively designated as Desulfotomaculum sp., and hydrogenotrophic methanogens was observed. The outcome of the competition could not be predicted. Growth of the mixed culture was totally inhibited at an H2S concentration of 250 mg/L. Poor attachment of sulphate‐reducing bacteria was observed in all experiments. The biomass concentration did not exceed 1.2 g/L, despite the presence of 50 g/L of pumice. The reason for this phenomenon remains to be understood. © 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 55: 807–814, 1997.

Microbial conversion of sulfur dioxide in flue gas to sulfide using bulk drug industry wastewater as an organic source by mixed cultures of sulfate reducing bacteria

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Challenges of a feasible route towards sustainability in environmental protection

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H2 enrichment from synthesis gas by Desulfotomaculumcarboxydivorans for potential applications in synthesis gas purification and biodesulfurization

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