A long-term study on the effect of magnetite supplementation in continuous anaerobic digestion of dairy effluent – Enhancement in process performance and stability

Baek, Gahyun; Kim, Jaai; Lee, Changsoo

doi:10.1016/j.biortech.2016.10.019

Cited by 110 publications

(52 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The authors proposed that the dominating electron transfer mechanisms might be shifted toward DIET from IHT in the presence of carbon cloth in a harsh environment such as acidic pH. It is in line with the phenomenon observed in anaerobic digesters, which became sour owing to imbalanced syntrophic mechanisms and then recovered rapidly after magnetite supplementation [6].…”

Section: Carbon Fiberssupporting

confidence: 59%

“…Much faster organic removal and methane production were observed, with corresponding producing and consuming patterns of intermediates (i.e., VFAs and hydrogen). The effect of magnetite addition to treat cheese whey was further investigated in the continuous mode to focus more on the process performance and stability over a long-term period (over 360 days) [6]. The reactor with added magnetite showed much better performance for both methane production and organic degradation.…”

Section: Iron Oxidesmentioning

confidence: 99%

“…Conventionally, this relationship is balanced by indirect interspecies electron transfer (IIET) using electron carriers like hydrogen and formate. A disruption of this syntrophy can lead to the accumulation of intermediates like volatile fatty acids (VFAs) as well as high hydrogen partial pressure; these can lead to a significant deterioration of AD efficiency [6].…”

Section: Introductionmentioning

confidence: 99%

“…We demonstrated that its use enhanced organic degradation and methanogenesis rates. Several other conductive materials, such as granular activated carbon (GAC), biochar, and carbon cloth, have also been reported to promote DIET in mixed cultures and defined co-cultures [6,[11][12][13][14].…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Role and Potential of Direct Interspecies Electron Transfer in Anaerobic Digestion

et al. 2018

Self Cite

View full text Add to dashboard Cite

Anaerobic digestion (AD) is an effective biological treatment for stabilizing organic compounds in waste/wastewater and in simultaneously producing biogas. However, it is often limited by the slow reaction rates of different microorganisms' syntrophic biological metabolisms. Stable and fast interspecies electron transfer (IET) between volatile fatty acid-oxidizing bacteria and hydrogenotrophic methanogens is crucial for efficient methanogenesis. In this syntrophic interaction, electrons are exchanged via redox mediators such as hydrogen and formate. Recently, direct IET (DIET) has been revealed as an important IET route for AD. Microorganisms undergoing DIET form interspecies electrical connections via membrane-associated cytochromes and conductive pili; thus, redox mediators are not required for electron exchange. This indicates that DIET is more thermodynamically favorable than indirect IET. Recent studies have shown that conductive materials (e.g., iron oxides, activated carbon, biochar, and carbon fibers) can mediate direct electrical connections for DIET. Microorganisms attach to conductive materials' surfaces or vice versa according to particle size, and form conductive biofilms or aggregates. Different conductive materials promote DIET and improve AD performance in digesters treating different feedstocks, potentially suggesting a new approach to enhancing AD performance. This review discusses the role and potential of DIET in methanogenic systems, especially with conductive materials for promoting DIET.

show abstract

Section: Carbon Fiberssupporting

confidence: 59%

Section: Iron Oxidesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Role and Potential of Direct Interspecies Electron Transfer in Anaerobic Digestion

et al. 2018

Self Cite

View full text Add to dashboard Cite

show abstract

“…Iron-oxide nanoparticles such as hematite and magnetite stimulated the growth of Geobacter by syntrophic association with methanogens via enhanced electric currents. Enhanced methanogenesis in a continuous anaerobic bioreactor with magnetite supplementation was also observed by Baek et al (2016). Hematite nanoparticles were coupled into an anaerobic system by Gadhe et al (2015), where both glucose utilization rate and H 2 production rate was significantly enhanced.…”

Section: Introductionmentioning

confidence: 79%

Promotion of Para-Chlorophenol Reduction and Extracellular Electron Transfer in an Anaerobic System at the Presence of Iron-Oxides

et al. 2018

View full text Add to dashboard Cite

Anaerobic dechlorination of chlorophenols often subjects to their toxicity and recalcitrance, presenting low loading rate and poor degradation efficiency. In this study, in order to accelerate p-chlorophenol (p-CP) reduction and extracellular electron transfer in an anaerobic system, three iron-oxide nanoparticles, namely hematite, magnetite and ferrihydrite, were coupled into an anaerobic system, with the performance and underlying role of iron-oxide nanoparticles elucidated. The reductive dechlorination of p-CP was notably improved in the anaerobic systems coupled by hematite and magnetite, although ferrihydrite did not plays a positive role. Enhanced dechlorination of p-CP in hematite or magnetite coupled anaerobic system was linked to the obvious accumulation of acetate, lower oxidation–reduction potential and pH, which were beneficial for reductive dechlorination. Electron transfer could be enhanced by Fe2+/Fe3+ redox couple on the iron oxides surface formed through dissimilatory iron-reduction. This study demonstrated that the coupling of iron-oxide nanoparticles such as hematite and magnetite could be a promising alternative to the conventional anaerobic reduction process for the removal of CPs from wastewater.

show abstract

Upgrading continuous H₂gas recovery from rice straw hydrolysate via fermentation process amended with magnetite nanoparticles

et al. 2019

View full text Add to dashboard Cite

Summary Continuous H2 production from alkali‐hydrolyzed rice straw in two mesophillic anaerobic baffled reactors (ABRs) was investigated in parallel. ABR1 was inoculated with thermally pretreated sludge while the sludge in ABR2 was amended with magnetite nanoparticles (MNPs). Both reactors were operated at organic loading rates (OLRs) ranged from 0.8 to 4.8 gCOD/L/day. The addition of MNPs significantly improved the H2 production and yield, ie, maximum H2 yield was 21.4 ± 3.2 and 60.6 ± 5.7 mL/g CODremoved for both ABR1 and ABR2, respectively, at OLR of 1.6 gCOD/L/day. Likewise, substrate degradation efficiency (SDE) was augmented from 48.4 ± 3.9% (ABR1) to 55.8 ± 4.2% (ABR2). The enhancement effect of MNPs can be emphasized by hydrogenase enzyme activity increase from 0.097 ± 0.013 to 0.205 ± 0.019 mg MBreduced/min at ABR1 and ABR2, respectively. Besides, ABR2 witnessed higher concentrations of acetate (HAc) and butyrate (HBu) coupled with lower values of propionate (HPr). Additionally, HAc/HBu ratio for ABR2 (3.03 ± 0.31) was higher than that for ABR1 (1.95 ± 0.29). Microbial analysis indicated that Bacillus and Clostridium species became dominant in mixed culture bacteria supplemented with MNPs. Furthermore, economic analysis revealed that the minimum payback period of 10.5 years at OLR of 3.2 gCOD/L/day was recorded for ABR2 compared with 14.6 years at OLR of 4.8 gCOD/L/day for ABR1.

show abstract

A long-term study on the effect of magnetite supplementation in continuous anaerobic digestion of dairy effluent – Enhancement in process performance and stability

Cited by 110 publications

References 33 publications

Role and Potential of Direct Interspecies Electron Transfer in Anaerobic Digestion

Role and Potential of Direct Interspecies Electron Transfer in Anaerobic Digestion

Promotion of Para-Chlorophenol Reduction and Extracellular Electron Transfer in an Anaerobic System at the Presence of Iron-Oxides

Upgrading continuous H₂gas recovery from rice straw hydrolysate via fermentation process amended with magnetite nanoparticles

Contact Info

Product

Resources

About

A long-term study on the effect of magnetite supplementation in continuous anaerobic digestion of dairy effluent – Enhancement in process performance and stability

Cited by 110 publications

References 33 publications

Role and Potential of Direct Interspecies Electron Transfer in Anaerobic Digestion

Role and Potential of Direct Interspecies Electron Transfer in Anaerobic Digestion

Promotion of Para-Chlorophenol Reduction and Extracellular Electron Transfer in an Anaerobic System at the Presence of Iron-Oxides

Upgrading continuous H2gas recovery from rice straw hydrolysate via fermentation process amended with magnetite nanoparticles

Contact Info

Product

Resources

About

Upgrading continuous H₂gas recovery from rice straw hydrolysate via fermentation process amended with magnetite nanoparticles