title: Denitrifying sulfide removal and carbon methanogenesis in a mesophilic, methanogenic culture.
abstract: The inhibitory effects of 90-189 mg l(-1) of sulfide and 25-75 mg-Nl(-1) of nitrate on methanogenesis were investigated in a mixed methanogenic culture using butyrate as carbon source. In the initial phase of 90 mg l(-1)S(2-) test, autotrophic denitrification of nitrate occurred with sulfide as the electron donor. Then the sulfate-reducing strains converted the produced sulfur back to sulfide via heterotrophic oxidation pathway. Methanogenesis was not markedly inhibited when 90 mg l(-1) of sulfide was dosed alone. When 25-75 mg-Nl(-1) of nitrate was presented, initiation of methanogenesis was seriously delayed. Nitrogen oxides (NO(x)), the intermediates for nitrate reduction via denitrification pathway, inhibited methanogenesis. The 90 mg l(-1) of sulfide favored heterotrophic dissimilatory nitrate reduction to ammonia (DNRA) pathway for nitrate reduction. Possible ways of maximizing methane production from an organic carbon-rich wastewater with high levels of sulfide and nitrate were discussed.
authors.affiliation: Department of Chemical Engineering, National Taiwan University, Taipei 106, Taiwan.
authors.forename: Biing-Teo
authors.initials: BT
authors.lastname: Wong
authors.forename: Duu-Jong
authors.initials: DJ
authors.lastname: Lee
mesh_terms: D001421:Bacteria, Anaerobic / Q000378:metabolism*; D019149:Bioreactors; D002087:Butyrates; D002849:Chromatography, Gas; D002851:Chromatography, High Pressure Liquid; D058440:Denitrification / Q000502:physiology*; D008697:Methane / Q000096:biosynthesis*; D009589:Nitrogen Oxides / Q000378:metabolism; D010084:Oxidation-Reduction; D013440:Sulfides / Q000378:metabolism*
chemical_list: D002087:Butyrates; D009589:Nitrogen Oxides; D013440:Sulfides; D008697:Methane