title: Metabolic divergence in simultaneous biological removal of nitrate and sulfide for elemental sulfur production under temperature stress.
abstract: The simultaneous removal of NO3-and HS-at temperature stress (25-10°C) is evaluated here. An expanded granular sludge bed (EGSB) reactor was run over 120days at N/S molar ratio of 0.35 (for S0production) under constant sulfur loading rate of 0.4kgS/m3d. The simultaneous removal of NO3-and HS-, was achieved at applied conditions. Average HS--S removal varied from 98 (25°C) to 89.2% at 10°C, with almost complete NO3-removal. Average S0yield ranged from 83.7 at 25°C to 67% at 10°C. The temperature drop caused a decrease in granular sludge accumulated S0fraction by nearly 2.5 times. Decreased temperature caused metabolic pathway change observed as higher SO42-production, apparently allowing the biomass to obtain more energy per HS-consumed. It is hypothesized that the metabolic shift is a natural response to compensate for temperature-induced changes in energy requirements.
authors.affiliation: University College of Southeast Norway, Kjølnes Ring 56, Porsgrunn 3918, Norway. Electronic address: michal.sposob@usn.no.
authors.forename: Michal
authors.initials: M
authors.lastname: Sposob
authors.affiliation: University College of Southeast Norway, Kjølnes Ring 56, Porsgrunn 3918, Norway.
authors.forename: Rune
authors.initials: R
authors.lastname: Bakke
authors.affiliation: University College of Southeast Norway, Kjølnes Ring 56, Porsgrunn 3918, Norway.
authors.forename: Carlos
authors.initials: C
authors.lastname: Dinamarca
mesh_terms: D019149:Bioreactors; D009566:Nitrates / Q000378:metabolism; D013440:Sulfides / Q000378:metabolism; D013455:Sulfur / Q000378:metabolism*; D013696:Temperature
chemical_list: D009566:Nitrates; D013440:Sulfides; D013455:Sulfur
keywords: Autotrophic denitrification; Elemental sulfur recovery; Sulfate production; Sulfide removal; Temperature impact