Implications of volatile fatty acid profile on the metabolic pathway during continuous sulfate reduction

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• 作者：Sueli M. Bertolino ; Isabel C.B. Rodrigues ; Renata Guerra-Sá ; Sé ; rgio F. Aquino ; Versiane A. Leã ; o ; ^{versiane@demet.em.ufop.br} ; ^{versiane.ufop@gmail.com}
• 关键词：UASB reactor ; Sulfate reduction ; Lactate ; Propionate ; Fermentation ; Metabolic pathways
• 刊名：Journal of Environmental Management
• 出版年：2012
• 期刊代码：82_03014797
• 类别：env
• 出版时间：30 July, 2012
• 卷：103
• 期：Complete
• 页码：15-23
• 文件大小：661 K

摘要

Volatile fatty acid (VFA) profile is an important parameter in anaerobic reactors because it enables the assessment of metabolic pathways. Volatile fatty acids were monitored during sulfate reduction in a UASB (upflow anaerobic sludge blanket) reactor treating 2 g/L sulfate concentration and with the organic loading increasing from 3.5 kg COD/m³ d to 5.9 kg COD/m³ d, for a 1-day residence time. In the absence of recirculation, the best outcome (65%reduction) was noticed with the lowest organic loading (3.55 kg/m³ d). When recirculation was applied, sulfate reduction yields increased to 89%, corresponding to a sulfate removal rate of 1.94 kg SO₄^{2鈭?/sup>/m3 d. The reactor performance was discussed in relation to microbial diversity and metabolic pathways. At high organic loading, two metabolic pathways account for lactate degradation: (i) lactate is oxidized to acetate and carbon dioxide by the incomplete-oxidizer SRB (sulfate-reducing bacteria) Desulfomonas, Desulfovibrio, Desulfolobus, Desulfobulbus and Desulfotomaculum spp.; (ii) lactate is converted to acetate by fermenting bacteria such as Clostridium sp. High propionate concentrations imply that there are low sulfate reduction efficiencies.}