Bio-Electrochemical Enhancement of Hydrogen and Methane Production in a Combined Anaerobic Digester (AD) and Microbial Electrolysis Cell (MEC) from Dairy Manure

Anaerobic digestion (AD) is a biological-based technology that generates methane-enriched biogas. A microbial electrolysis cell (MEC) uses electricity to initiate bacterial oxidization of organic matter to produce hydrogen. This study determined the effect of energy production and waste treatment when using dairy manure in a combined AD and MEC (AD-MEC) system compared to AD without MEC (AD-only). In the AD-MEC system, a single chamber MEC (150 mL) was placed inside a 10 L digester on day 20 of the digestion process and run for 272 h (11 days) to determine residual treatment and energy capacity with an MEC included. Cumulative H2 and CH4 production in the AD-MEC (2.43 L H2 and 23.6 L CH4) was higher than AD-only (0.00 L H2 and 10.9 L CH4). Hydrogen concentration during the first 24 h of MEC introduction constituted 20% of the produced biogas, after which time the H2 decreased as the CH4 concentration increased from 50% to 63%. The efficiency of electrical energy recovery (ηE) in the MEC was 73% (ηE min.) to 324% (ηE max.), with an average increase of 170% in total energy compared to AD-only. Chemical oxygen demand (COD) removal was higher in the AD-MEC (7.09 kJ/g COD removed) system compared to AD-only (6.19 kJ/g COD removed). This study showed that adding an MEC during the digestion process could increase overall energy production and organic removal from dairy manure.

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Optimising the Hydraulic Retention Time in a Pilot-Scale Microbial Electrolysis Cell to Achieve High Volumetric Treatment Rates Using Concentrated Domestic Wastewater

Molecules ◽

10.3390/molecules25122945 ◽

2020 ◽

Vol 25 (12) ◽

pp. 2945 ◽

Cited By ~ 3

Author(s):

Daniel D. Leicester ◽

Jaime M. Amezaga ◽

Andrew Moore ◽

Elizabeth S. Heidrich

Keyword(s):

Retention Time ◽

Hydraulic Retention Time ◽

Oxygen Demand ◽

Domestic Wastewater ◽

Direct Analysis ◽

Pilot Scale ◽

Electrolysis Cell ◽

Treatment Technique ◽

Microbial Electrolysis Cell ◽

Microbial Electrolysis

Bioelectrochemical systems (BES) have the potential to deliver energy-neutral wastewater treatment. Pilot-scale tests have proven that they can operate at low temperatures with real wastewaters. However, volumetric treatment rates (VTRs) have been low, reducing the ability for this technology to compete with activated sludge (AS). This paper describes a pilot-scale microbial electrolysis cell (MEC) operated in continuous flow for 6 months. The reactor was fed return sludge liquor, the concentrated filtrate of anaerobic digestion sludge that has a high chemical oxygen demand (COD). The use of a wastewater with increased soluble organics, along with optimisation of the hydraulic retention time (HRT), resulted in the highest VTR achieved by a pilot-scale MEC treating real wastewater. Peak HRT was 0.5-days, resulting in an average VTR of 3.82 kgCOD/m3∙day and a 55% COD removal efficiency. Finally, using the data obtained, a direct analysis of the potential savings from the reduced loading on AS was then made. Theoretical calculation of the required tank size, with the estimated costs and savings, indicates that the use of an MEC as a return sludge liquor pre-treatment technique could result in an industrially viable system.

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Long-term performance of a microbial electrolysis cell operated with periodic disconnection of power supply

RSC Advances ◽

10.1039/c8ra01863d ◽

2018 ◽

Vol 8 (30) ◽

pp. 16842-16849 ◽

Cited By ~ 2

Author(s):

S. A. Hussain ◽

M. Perrier ◽

B. Tartakovsky

Keyword(s):

Chemical Oxygen Demand ◽

Power Supply ◽

Oxygen Demand ◽

Electrolysis Cell ◽

Microbial Electrolysis Cell ◽

New Approach ◽

Microbial Electrolysis ◽

Long Term Performance ◽

Term Performance

This study describes a new approach for achieving stable long-term performance and maximizing removal of chemical oxygen demand (COD) in a Microbial Electrolysis Cell (MEC) by periodic disconnection of the MEC power supply.

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An intermittent power supply scheme to minimize electrical energy input in a microbial electrolysis cell assisted anaerobic digester

Bioresource Technology ◽

10.1016/j.biortech.2020.124109 ◽

2021 ◽

Vol 319 ◽

pp. 124109 ◽

Cited By ~ 2

Author(s):

Basem S. Zakaria ◽

Bipro Ranjan Dhar

Keyword(s):

Power Supply ◽

Energy Input ◽

Electrical Energy ◽

Anaerobic Digester ◽

Electrolysis Cell ◽

Microbial Electrolysis Cell ◽

Microbial Electrolysis

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A novel microbial electrolysis cell-A/O system treating cotton dyeing pretreatment wastewater: performance and microbial diversity analysis

Water Science & Technology ◽

10.2166/wst.2019.216 ◽

2019 ◽

Vol 79 (11) ◽

pp. 2156-2165 ◽

Cited By ~ 1

Author(s):

Donglei Wu ◽

Mingjie Zhang ◽

Meiqing Yang ◽

Shuwen Du ◽

Weiwang Chen ◽

...

Keyword(s):

Microbial Diversity ◽

Applied Voltage ◽

Textile Industry ◽

Oxygen Demand ◽

Electrolytic Cell ◽

Electrolysis Cell ◽

Microbial Electrolysis Cell ◽

Activity Increase ◽

Microbial Electrolysis ◽

Cotton Dyeing

Abstract The textile industry is developing rapidly in China. It generates large volumes of cotton dyeing pretreatment wastewater (CDPW). CDPW contains high concentrations of pollutants characterized by their strongly alkaline and recalcitrant nature for microbial degradation. This project aimed to evaluate the performance of a microbial electrolysis cell (MEC) coupled with anoxic/oxic (A/O) system (MEC-A/O) in treating CDPW, as well as analyze changes in microbial diversity. The results indicated that the effect of biological treatment in an electrolytic cell to treat CDPW was optimal at the voltage of 0.6V. The chemical oxygen demand (COD) removal efficiency under optimum conditions was 69.13%, higher than that of the A/O system alone (48.93%). Within a certain range, applied voltage was able to enhance microbial activity, increase the sludge concentration and enlarge the sludge particle size. At the same time, the applied voltage could effectively increase the abundance and the diversity of Bacteria and Archaea, as well as accelerate the degradation of pollutants.

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An integrated microbial electrolysis-anaerobic digestion process combined with pretreatment of wastewater solids to improve hydrogen production

Environmental Science Water Research & Technology ◽

10.1039/c7ew00189d ◽

2017 ◽

Vol 3 (6) ◽

pp. 1073-1085 ◽

Cited By ~ 8

Author(s):

Jeff R. Beegle ◽

Abhijeet P. Borole

Keyword(s):

Anaerobic Digestion ◽

Hydrogen Production ◽

Hydrogen Gas ◽

Cell Process ◽

Electrolysis Cell ◽

Microbial Electrolysis Cell ◽

Thermal Hydrolysis ◽

Anaerobic Digestion Process ◽

Digestion Process ◽

Microbial Electrolysis

This paper explores an integrated anaerobic digestion/microbial electrolysis cell process (ADMEC) with alkaline or thermal hydrolysis pretreatment methods to improve COD conversion to hydrogen gas.

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