Bioelectrochemical enhancement of hydrogen and methane production from the anaerobic digestion of sewage sludge in single-chamber membrane-free microbial electrolysis cells

Guo, Xuesong; Liu, Junxin; Xiao, Benyi

doi:10.1016/j.ijhydene.2012.11.087

Cited by 136 publications

(37 citation statements)

References 29 publications

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“…Guo et al reported that the hydrogen production was 2.5 and 7.7 mL (per 1.8 g VSS ) from sludgebased MECs using a Ti/Ru electrode with voltages of 1.4 and 1.8 V, respectively. 35 from sludge digestion in a MEC at 2 V with only 75% of the highest energy efficiency. 38 Compared with the energy and environmental benefits, Fe loss was unlikely a problem.…”

Section: Significances Of This Workmentioning

confidence: 99%

Enhancement of sludge decomposition and hydrogen production from waste activated sludge in a microbial electrolysis cell with cheap electrodes

Feng

Liu

Zhang

2015

Environ. Sci.: Water Res. Technol.

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Low hydrogen production from anaerobic digestion of sludge has greatly limited the application of biological hydrogen-producing technology. An Fe/graphite electrode was installed into an anaerobic digester to enhance the hydrogen production from waste sludge in this study. The electrode accelerated the decomposition of the sludge, and the production of short-chain fatty acids was 3.5 folds of that in a control anaerobic reactor with no electrode. The hydrogen production was 90.6 mL g VSS −1, while it was almost undetectable in the control. The results suggested that the hydrogen was produced from the cathodic reduction of H + coupling with the anodic oxidation of sludge. The excessive consumption of the cathodic H + drove the pH up to 9.2-9.5 in the electric-anaerobic system which inevitably inhibited the occurrence of methanogenesis. This led to quite low methane production in this electric-anaerobic system. The microbial analysis showed that exoelectrogens were enriched in the presence of an Fe electrode. It catalyzed the anodic oxidation of the sludge to produce more electrons for the cathodic hydrogen production. Raising the voltage supply boosted the H 2 production, but the net energy output was obtained at 0.3 and 0.6 V.

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Section: Significances Of This Workmentioning

confidence: 99%

Enhancement of sludge decomposition and hydrogen production from waste activated sludge in a microbial electrolysis cell with cheap electrodes

Feng

Liu

Zhang

2015

Environ. Sci.: Water Res. Technol.

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“…One new and important application of MECs is the addition of electrodes directly into an anaerobic digester, in order to improve performance and increase the methane concentration in the product gas78910. Such an integration is not practical using MFCs as the anaerobic digestion (AD) process requires oxygen free environment.…”

mentioning

confidence: 99%

Set anode potentials affect the electron fluxes and microbial community structure in propionate-fed microbial electrolysis cells

Hari

Katuri

Logan

et al. 2016

Sci Rep

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Anode potential has been shown to be a critical factor in the rate of acetate removal in microbial electrolysis cells (MECs), but studies with fermentable substrates and set potentials are lacking. Here, we examined the impact of three different set anode potentials (SAPs; −0.25, 0, and 0.25 V vs. standard hydrogen electrode) on the electrochemical performance, electron flux to various sinks, and anodic microbial community structure in two-chambered MECs fed with propionate. Electrical current (49–71%) and CH4 (22.9–41%) were the largest electron sinks regardless of the potentials tested. Among the three SAPs tested, 0 V showed the highest electron flux to electrical current (71 ± 5%) and the lowest flux to CH4 (22.9 ± 1.2%). In contrast, the SAP of −0.25 V had the lowest electron flux to current (49 ± 6%) and the highest flux to CH4 (41.1 ± 2%). The most dominant genera detected on the anode of all three SAPs based on 16S rRNA gene sequencing were Geobacter, Smithella and Syntrophobacter, but their relative abundance varied among the tested SAPs. Microbial community analysis implies that complete degradation of propionate in all the tested SAPs was facilitated by syntrophic interactions between fermenters and Geobacter at the anode and ferementers and hydrogenotrophic methanogens in suspension.

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“…As a result, low acetate concentration was consistently reported in anaerobic digestion systems coupled with the MEC reactions Guo et al, 2013;Choi and Ahn, 2014;Wang et al, 2014;Asztalos and Kim, 2015). These literature articles strongly indicate that the presence of the MEC reactions reduces acetate concentration and thus leads to supplementing the rate-limiting acetoclastic methanogenesis reaction.…”

Section: Acetoclastic Methanogenesis At 6-day Srtmentioning

confidence: 85%

“…Eventually, we aimed to reduce the long SRT requirement of mesophilic anaerobic digesters and investigate how the shortened SRT conditions along with the MEC reactions affect other biological reactions, including acetoclastic and hydrogenotrophic methanogenesis. There are a number of previous studies where wastewater sludge or animal manure wastewater was treated in bioelectrochemical systems (Pham et al, 2006;Rodrigo et al, 2007;Tartakovsky et al, 2011;Liu et al, 2012;Lu et al, 2012;Ge et al, 2013;Guo et al, 2013;Tartakovsky et al, 2014). A recent study also showed enhanced CH4 production and decomposition of individual organic acids by implementing an MEC in an anaerobic digester .…”

Section: Introductionmentioning

confidence: 99%

Lab-Scale Experiment and Model Study on Enhanced Digestion of Wastewater Sludge using Bioelectrochemical Systems

Asztalos¹,

Kim²

2015

J ENV INFORM

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ABSTRACT. Anaerobic digestion is the slowest process in municipal wastewater treatment, requiring at least 15 days of SRT (solids retention time). Here, we implemented microbial electrolysis cells (MECs) in anaerobic digesters to shorten the long SRT requirement. The MEC bioanode oxidizes acetic acid while the cathode produces H2 gas. The electrode reactions can expedite acetic acid decomposition and thus enhance the rate of biosolids destruction because acetoclastic methanogenesis is known to be the rate-limiting step in conventional anaerobic digestion. A lab-scale electrically-assisted digester (EAD) with the MEC reactions was operated under a continuous fed-batch mode using raw wastewater sludge. Additionally, a steady-state model was developed by incorporating the MEC reaction in ADM1 (Anaerobic Digestion Model No.1 by International Water Association). In experiments, the EAD achieved 55% VSS (volatile suspended solids) removal and 61% COD (chemical oxygen demand) removal at a 6-day SRT while the control digester (built with the same electrode components but no MEC reactions induced) showed only 47% VSS removal and 50% COD removal. This result indicates that the SRT requirement can be substantially reduced by implementing the MEC reactions in mesophilic anaerobic digestion. Under a 14-day or 2-day SRT condition, however, the EAD did not show meaningful improvements on the COD and VSS removal compared to the control digester. Hydrogenotrophic methanogenesis was sufficiently rapid as H2 gas was not detected in produced biogas. The mathematical simulation results demonstrated that the MEC reactions substantially reduce acetic acid concentration and thus supplement the slow acetoclastic methanogenesis reaction.

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Bioelectrochemical enhancement of hydrogen and methane production from the anaerobic digestion of sewage sludge in single-chamber membrane-free microbial electrolysis cells

Cited by 136 publications

References 29 publications

Enhancement of sludge decomposition and hydrogen production from waste activated sludge in a microbial electrolysis cell with cheap electrodes

Enhancement of sludge decomposition and hydrogen production from waste activated sludge in a microbial electrolysis cell with cheap electrodes

Set anode potentials affect the electron fluxes and microbial community structure in propionate-fed microbial electrolysis cells

Lab-Scale Experiment and Model Study on Enhanced Digestion of Wastewater Sludge using Bioelectrochemical Systems

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