Bioaugmentation with Mixed Hydrogen-Producing Acetogen Cultures Enhances Methane Production in Molasses Wastewater Treatment

Abstract

Hydrogen-producing acetogens (HPA) have a transitional role in anaerobic wastewater treatment. Thus, bioaugmentation with HPA cultures can enhance the chemical oxygen demand (COD) removal efficiency and CH4 yield of anaerobic wastewater treatment. Cultures with high degradation capacities for propionic acid and butyric acid were obtained through continuous subculture in enrichment medium and were designated as Z08 and Z12. Bioaugmentation with Z08 and Z12 increased CH4 production by glucose removal to 1.58. Bioaugmentation with Z08 and Z12 increased the COD removal rate in molasses wastewater from 71.60% to 85.84%. The specific H2 and CH4 yields from COD removal increased by factors of 1.54 and 1.63, respectively. Results show that bioaugmentation with HPA-dominated cultures can improve CH4 production from COD removal. Furthermore, hydrogen-producing acetogenesis was identified as the rate-limiting step in anaerobic wastewater treatment.

Characteristics of Biohydrogen Production and Performance of Hydrogen-Producing Acetogen by Increasing Normal Molasses Wastewater Proportion in Anaerobic Baffled Reactor

“…However, in Stage III, the contribution rate decreased to 77.4% because the biohydrogen production efficiency in compartment II was significantly enhanced. Although a certain amount of hydrogenproducing acetogens was enriched in other compartments, their contribution to the total biohydrogen production of ABR was relatively low due to the limitation of fermentation substrates (carbohydrates) and hydrogen consumption of methanogens and homoacetogen [21]. Compartment 2 showed the highest contribution rate of 18.5% in Stage III, whereas compartment 4 presented little contribution rate for biohydrogen production.…”

Effect of Hydraulic Retention Time on Anaerobic Baffled Reactor Operation: Enhanced Biohydrogen Production and Enrichment of Hydrogen-producing Acetogens

“…In Compartment IV, the biogas production rate decreased the least; the reason was attributed to the further enrichment of methanogens (Figures 4-7) in Stage II. The presence and metabolism of methanogens were conducive to the enrichment of HPA [2,6]. However, the biohydrogen production efficiency in Compartment IV was low due to the hydrogen consumption [23,24] and still showed a decreasing trend.…”

“…For Compartment IV, the content of biohydrogen in biogas increased significantly in the previous stage and then decreased, while the content of methane significantly increased. Therefore, the methanogens in Compartment IV were further enriched and presented dominant position [2,6,14] although the biomass was relatively low. The presence and metabolism of methanogens were conducive to the enrichment of HPA.…”

“…The specific biohydrogen production rate also decreased from 24.34 to 2.7 L/(kg MLVSS·d). enrichment of biohydrogen-producing acetogens, the specific hydrogen and methane yields from COD removal increased by factors of 1.54 and 1.63 in normal molasses wastewater treatment [2]. In addition, lipid production through microalgae cultivation in normal molasses wastewater treatment presented its economic feasibility when a lipid content of 28.9% and lipid productivity of 94.4 mg·m −3 ·d −1 were finally obtained [3,4].The use of fermentation to produce biohydrogen is a process in which hydrogen-producing microorganisms metabolize organic matter to produce hydrogen under anaerobic conditions [5].…”

Treatment of microfiber alkali weight‐reduction wastewater with high salt concentration by Fenton oxidation and bacterial degradation

“…They can effectively reduce the contaminant load by transforming it into less dangerous compounds through the specialised‐microorganisms which include indigenous or allochthonous wild‐types or genetically modified organisms (Park et al , 2008). Many screened strains or acclimated microbial consortia are shown significant ability of degradating recalcitrant or toxic organics (Chen et al , 2016; Wang et al , 2018). But up to now, there have been few reports on the biological degradation of EG.…”