Assessing main process mechanism and rates of sulfate reduction by granular biomass fed with glycerol under sulfidogenic conditions

Sulfate-reducing bioreactors for sulfide production are the initial stage of processes targeting elemental sulfur recovery from sulfate-rich effluents. In this work, principal reactions involved in glycerol fermentation and sulfate reduction using its products as electron donors were assessed together with their specific consumption/production rates. A battery batch activity tests without performed each product a non-methanogenic but sulfidogenic granular sludge an up-flow anaerobic blanket (UASB) reactor operated under long-term while fed crude glycerol. As result, mechanistic approach based on experimental observations is proposed work. Glycerol was mainly fermented to 1,3-propanediol, ethanol, formate, propionate acetate by fermentative bacteria. All organic intermediates found be further used reducing bacteria (SRB) except acetate. The most abundant genus detected conditions Propionispora (15.2%), Dysgonomonas (13.2%), Desulfobulbus (11.6%) Desulfovibrio (10.8%). last two SRB genera accounted 22.4% total amount retrieved sequences, which probably performing incomplete oxidation carbon source UASB reactor. single substrates, rates (SRRs) low molecular weight (MW) sources (formate ethanol) 39% higher than those high-MW ones (propionate, 1,3-propanediol butanol). However, SRRs glycerol-fed showed that played major role addition formate ethanol.