Sulfate reduction during the acidification of sucrose at pH 5 under thermophilic (55 degrees C) conditions. II: effect of sulfide and COD/SO(2-)(4) ratio.
This work studied the effect of the sulfide concentration and COD/SO(2-)(4) ratios (4 and 1) on sulfate reduction and acidification in a thermophilic (55 degrees C) UASB reactor fed with sucrose (4 g COD(l(reactor)d)(-1)) operated at a reactor mixed liquor pH controlled at 5 for a period of 301 days. When implementing N(2) stripping, sulfate reduction efficiencies up to 95%, corresponding to volumetric sulfate reduction rates of 0.87 and 4.2g (l(reactor)d)(-1) at the COD/SO(2-)(4) ratios of 4 and 1, respectively, were achieved. Sulfide was toxic to sulfate reduction at a total dissolved sulfide concentration of 100 mg l(-1). Acidification was always complete and acetate was the only form of substrate in the effluent at a COD/SO(2-)(4) ratio of 1. The sludge was well retained in the reactor and kept its granular shape throughout the reactor run.
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Sub-Department of Environmental Technology, Wageningen University Biotechnion - Bomenweg, 2, P.O. Box 8129, 6700 EV Wageningen, The Netherlands.
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D000143:Acids / Q000378:metabolism*; D000438:Alcohols / Q000032:analysis; D056804:Biofuels; D019149:Bioreactors; D004583:Electrons; D005232:Fatty Acids, Volatile / Q000032:analysis; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D019344:Lactic Acid / Q000032:analysis; D010084:Oxidation-Reduction / Q000187:drug effects; D010100:Oxygen / Q000378:metabolism*; D012722:Sewage / Q000382:microbiology; D013395:Sucrose / Q000378:metabolism*; D013431:Sulfates / Q000378:metabolism*; D013440:Sulfides / Q000494:pharmacology*; D013696:Temperature; D014865:Waste Disposal, Fluid
D000143:Acids; D000438:Alcohols; D056804:Biofuels; D005232:Fatty Acids, Volatile; D012722:Sewage; D013431:Sulfates; D013440:Sulfides; D019344:Lactic Acid; D013395:Sucrose; D010100:Oxygen