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Microbial Reduction of Sulfur Dioxide with Anaerobically Digested Municipal Sewage Biosolids as Electron Donors
Author(s) -
Selvaraj Punjai T.,
Sublette Kerry L.
Publication year - 1995
Publication title -
biotechnology progress
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.572
H-Index - 129
eISSN - 1520-6033
pISSN - 8756-7938
DOI - 10.1021/bp00032a006
Subject(s) - biosolids , sewage sludge , chemistry , sulfur dioxide , sewage , sulfur , reduction (mathematics) , environmental chemistry , environmental science , pulp and paper industry , environmental engineering , inorganic chemistry , organic chemistry , mathematics , engineering , geometry
A concentrated stream of sulfur dioxide (SO 2 ) is produced by regeneration of the sorbent in certain new regenerable processes for the desulfurization of flue gas. We have previously proposed that this SO 2 can be converted to elemental sulfur for disposal or byproduct recovery using a microbial/Claus process. In this process, two‐thirds of the SO 2 ‐reducing gas stream would be contacted with a mixed culture containing sulfate‐reducing bacteria (SRB), where SO 2 would act as an electron acceptor with reduction to hydrogen sulfide (H 2 S). This H 2 S could then be recombined with the remaining SO 2 and sent to a Claus unit to produce elemental sulfur. The sulfate‐reducing bacterium, Desulfouibrio desulfuricans , has been immobilized by coculture with flocforming heterotrophs from an anaerobic digester, resulting in a SO 2 ‐reducing floc that may be collected from the effluent of a continuous reactor for recycle by gravity sedimentation. The carbon and energy source for these cultures was anaerobically digested municipal sewage solids. The maximum specific activity for SO 2 reduction in these cultures, in terms of dry weight of D. desulfuricans biomass, was 9.1 mmol of SO 2 /h. g. The stoichiometry with respect to the electron donor was 15.5 mg of soluble COD/mmol of SO 2 reduced.