Hydrogen sulfide production from elemental sulfur by Desulfovibrio desulfuricans in an anaerobic bioreactor

Abstract

Feasibility of elemental sulfur reduction by Desulfovibrio desulfuricans in anaerobic conditions in a stirred reactor was studied. Hydrogen was used as energy source, whereas the carbonated species were bicarbonate and yeast extract. Attention was paid to reactor engineering aspects, biofilm formation on the sulfur surface, hydrogen sulfide formation rate and kinetics limitations of the sulfur reduction. D. desulfuricans formed stable biofilms on the sulfur surface. It was found that active sulfur surface availability limits the reaction rate. The reaction rate was first order with respect to sulfur and hydrogen velocity had no effect in the reaction rate for the range 8.2 x 10(-2) to 4.1 x 10(-1) Nm(3) m(-2) min(-1). At a superficial gas velocity (u(G)) = 3.1 x 10(-2) Nm(3) m(-2) min(-1), H(2)S(g) production rate decreased due to a deficient H(2)S stripping. A maximum H(2)S(g) production rate of 2.1 g H(2)S L(-1) d(-1) was achieved during 5 days with an initial sulfur density of 4.7% (w/v).

Biological S0reduction at neutral (pH 6.9) and acidic (pH 3.8) conditions: Performance and microbial community shifts in a H2/CO2-fed bioreactor

“…For instance, Guo et al (2021) reports VSPR reaching 0.844 ± 0.115 g S 2-•L -1 •d -1 at pH 3.8 and 25 °C while Sun et al (2020b) found VSPR up to 0.845 g S 2-•L -1 •d -1 at pH 3.5 and room temperature (not specified). Furthermore, the VSPR at the circumneutral pH is also in the same order of magnitude of those reported from research performed at laboratoryscale (Escobar et al, 2007;Zhang et al, 2018a) and industrial applications (Gonzalez-Contreras et al, 2016), under comparable pH and temperature conditions. This consistency in VSPR across studies, transcending differences in inoculum, electron donor, S 0 source, operational parameters, reactor configurations, and scale, hints at an intrinsic limit in microbial S 0 -reduction rates.…”

Long Chain Fatty Acid Degradation Coupled to Biological Sulfidogenesis: A Prospect for Enhanced Metal Recovery

“…The presence of Desulfovibrio species with elemental sulfur as electron acceptor opens possibilities for further studies, as there are no reports of extended sulfidogenesis from the reduction of sulfur coupled to the degradation of complex organic matter by this group. Escobar et al (2007) showed the feasibility of elemental sulfur reduction by Desulfovibrio desulfuricans with hydrogen as electron donor and obtained maximal sulfide production rates of 2.1 g H 2 S L −1 d −1 . However, Biebl and Pfennig (1977) tested D. desulfuricans and D. vulgaris and no growth on elemental sulfur was observed, but slow and definite growth was observed for D. gigas.…”

“…The aquatic environmental pollution originating from heavy metals in solution is of utmost relevance due to its impact on public health, environment, and economy. Sulfidogenic reactors have become suitable alternatives for the treatment of metalrich wastewaters (Escobar et al, 2007;Gallegos-Garcia et al, 2009), with high levels of metals precipitated as highly insoluble metal sulfides. As a proof of concept, the stripping of sulfide for heavy metal precipitation shown in this study (Figure 6) increased the possibility of degrading the highly energetic bonds in LCFA compounds, mitigating the complexity of FOGs in lipid-rich wastewater while removing and recycling metals from metallurgical emissions.…”

Anaerobic Processes

“…In an anaerobic stirred reactor, fed in batches, sulfur could be biologically reduced with Desulfovibrio desulfuricans, however, available surface area of the sulfur limited the rate of reaction (Escobar et al, 2007). (Dar, Stams et al, 2007).…”