In a biotechnological process for hydrogen sulfide (H2S) removal from gas streams, operating at natronophilic conditions, formation of thiosulfate (S2O3(2-)) is unfavorable, as it leads to a reduced sulfur production. Thiosulfate formation was studied in gas-lift bioreactors, using natronophilic biomass at [Na+] + [K+] = 2 mol L(-1). The results show that at sulfur producing conditions, selectivity for S2O3(2-) formation mainly depends on the equilibrium between free sulfide (HS(-)) and polysulfide (Sx(2-)), which can be controlled via the pH. At pH 8.6, 21% of the total dissolved sulfide is present as Sx(2-) and selectivity for S2O3(2-) formation is 3.9-5.5%. At pH 10, 87% of the total dissolved sulfide is present as Sx(2-) and 20-22% of the supplied H2S is converted to S2O3(2-), independent of the H2S loading rate. Based on results of bioreactor experiments and biomass activity tests, a mechanistic model is proposed to describe the relation between S2O3(2-) formation and pH.
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http://dx.doi.org/10.1021/es7024438 | DOI Listing |
Sci Total Environ
January 2025
Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China.
Despite many studies on the environmental cycling of As, Fe, and S, sulfide (S(-II))-induced hydrous ferric arsenate (HFA) transformation remains to be elucidated. Herein, we investigated the anaerobic reaction of HFA with S(-II) at three environmental concentrations (1, 10, and 50 mM) at pH 48. Changes in solid-phase As, Fe, and S speciation were investigated by XRD, FTIR, Raman, XPS, synchrotron XANES, SEM, and TEM.
View Article and Find Full Text PDFWater Res
February 2025
National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China.
Sulfur-based autotrophic denitrification (SADN) offers new pathway for nitrite supply. However, sequential transformation of nitrogen and sulfur forms, and the functional microorganisms driving nitrite accumulation in SADN with different reduced inorganic sulfur compounds (RISCs), remain unclear. Desirable nitrite accumulation was achieved using elemental sulfur (S-group), sulfide (S-group) and thiosulfate (SO-group) as electron donors.
View Article and Find Full Text PDFInt J Mol Sci
November 2024
Research Laboratory "Medical Digital Images Based on the Basic Model", Department of Bioengineering, Faculty of Bioengineering and Veterinary Medicine, Don State Technical University, Rostov-on-Don 344000, Russia.
Hydrogen sulfide (HS) donors are emerging as promising candidates for neuroprotective agents. However, HS-dependent neuroprotective mechanisms are not yet fully understood. We have demonstrated that an HS donor (sodium sulfide, NaS) reduces the expression of inducible NO synthase (iNOS) and amyloid-beta precursor protein (APP) in damaged neural tissue at 24 h and 7 days following traumatic brain injury (TBI).
View Article and Find Full Text PDFEnviron Res
January 2025
School of Environmental and Municipal Engineering, Tianjin Chengjian University, Jinjing Road 26, Tianjin, 300384, China.
Thiosulfate-driven denitrification coupled with anammox (TDDA) has garnered interest for its efficient and innovative nitrogen removal capabilities. However, the intricate dynamics of the internal microbial community and the specific characteristics of anaerobic ammonium oxidizing bacteria (AnAOB) remain incompletely understood. This study combines experimental methods with density functional theory (DFT) calculations to address these gaps.
View Article and Find Full Text PDFSci Total Environ
December 2024
Laboratory of Environmental Technology, INET, Tsinghua University, Beijing 100084, PR China; Beijing Key Laboratory for Radioactive Waste Treatment, Tsinghua University, Beijing 100084, PR China. Electronic address:
Sulfur-based mixotrophic denitrification has significant potential as a promising denitrification technology for treating low ratio of carbon-to‑nitrogen (C/N) wastewater. This paper provided an in-depth and comprehensive overview of the sulfur-based mixotrophic denitrification process and discussed the underlying mechanisms and functional microorganisms. Possible electron transfer pathways involved in the sulfur-based mixotrophic denitrification process are also analyzed in detail.
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