The Experts below are selected from a list of 3036 Experts worldwide ranked by ideXlab platform

Boris Tartakovsky - One of the best experts on this subject based on the ideXlab platform.

  • a comparison of Microbial fuel Cell and Microbial Electrolysis Cell biosensors for real time environmental monitoring
    Bioelectrochemistry, 2019
    Co-Authors: Ademola Adekunle, Vijaya Raghavan, Boris Tartakovsky
    Abstract:

    Abstract This study compares the biosensing performance of a Microbial fuel Cell (MFC) and a Microbial Electrolysis Cell (MEC). Initial tests provided a qualitative comparison of MFC and MEC currents after the anode compartment liquid (anolyte) was spiked with acetate, or sulphates of NH4+, Na+, Mg2+, Fe2+, or a fertilizer solution. Current measurements showed that the MFC sensor had a faster response time, higher sensitivity, and faster recovery time after the spike. Following the spike tests, the MFC and MEC were operated in a continuous flow mode at several influent concentrations of acetate, and sulphates of NH4+, Na+, and Fe2+. The continuous flow tests confirmed the better performance of the MFC sensor, which was selected for further experiments. Two MFC sensors were used for real-time (on-line) COD measurements of brewery wastewater. Regression analysis showed a strong correlation between the MFC power output and COD concentrations in the anode compartment with a coefficient of determination (R2) of 0.97. Overall, results of this study suggest that an MFC-based sensor can be successfully used as a simple and cost-efficient real-time monitoring tool.

  • Removal of organic carbon and nitrogen in a membraneless flow-through Microbial Electrolysis Cell.
    Enzyme and microbial technology, 2017
    Co-Authors: Abid Hussain, Frederique Matteau Lebrun, Boris Tartakovsky
    Abstract:

    This study evaluated performance of an upflow membraneless Microbial Electrolysis Cell (MEC) with flow-through electrodes for wastewater treatment. First, methane production and COD removal were evaluated in continuous flow experiments carried out using synthetic and municipal wastewater. A 29-75% increase in methane production was observed under bioelectrochemical conditions as compared to an anaerobic control. Next, simultaneous removal of COD and nitrogen was studied under microaerobic conditions created by continuous air injection to the anodic compartment of the MEC. While the presence of oxygen decreased Coulombic efficiency due to aerobic degradation of COD, enhanced ammonium removal with near zero nitrite and nitrate effluent concentrations was observed. Evidence of direct ammonium oxidation at the anode as well as nitrite and nitrate reduction at the cathode was obtained by comparing performances of MECs operated under anaerobic and microaerobic conditions with the control reactor operated at zero applied voltage.

  • Optimizing the electrode size and arrangement in a Microbial Electrolysis Cell.
    Bioresource technology, 2011
    Co-Authors: L. Gil-carrera, P. Mehta, Adrián Escapa, Antonio Morán, V. García, Serge R. Guiot, Boris Tartakovsky
    Abstract:

    This study investigates the influence of anode and cathode size and arrangement on hydrogen production in a membrane-less flat-plate Microbial Electrolysis Cell (MEC). Protein measurements were used to evaluate Microbial density in the carbon felt anode. The protein concentration was observed to significantly decrease with the increase in distance from the anode–cathode interface. Cathode placement on both sides of the carbon felt anode was found to increase the current, but also led to increased losses of hydrogen to hydrogenotrophic activity leading to methane production. Overall, the best performance was obtained in the flat-plate MEC with a two-layer 10 mm thick carbon felt anode and a single gas-diffusion cathode sandwiched between the anode and the hydrogen collection compartments.

  • Multi-Population Model of a Microbial Electrolysis Cell
    Environmental science & technology, 2011
    Co-Authors: R.p. Pinto, Adrián Escapa, Bala Srinivasan, Boris Tartakovsky
    Abstract:

    This work presents a multi-population dynamic model of a Microbial Electrolysis Cell (MEC). The model describes the growth and metabolic activity of fermentative, electricigenic, methanogenic acetoclastic, and methanogenic hydrogenophilic microorganisms and is capable of simulating hydrogen production in a MEC fed with complex organic matter, such as wastewater. The model parameters were estimated with the experimental results obtained in continuous flow MECs fed with acetate or synthetic wastewater. Following successful model validation with an independent data set, the model was used to analyze and discuss the influence of applied voltage and organic load on hydrogen production and COD removal.

  • Hydrogen production in a Microbial Electrolysis Cell with nickel-based gas diffusion cathodes
    Journal of Power Sources, 2010
    Co-Authors: M F Manuel, Serge R. Guiot, Haijiang Wang, Vladimir Neburchilov, Boris Tartakovsky
    Abstract:

    Abstract Gas diffusion cathodes with Ni alloy and Ni catalysts manufactured by chemical deposition were tested for H2 production in a Microbial Electrolysis Cell (MEC). In a continuous flow MEC, multi-component cathodes containing Ni, Mo, Cr, and Fe, at a total catalyst load of 1 mg cm−2 on carbon support demonstrated stable H2 production at rates of 2.8 – 3.7 L L R − 1 d − 1 with only 5% methane in the gas stream. Furthermore, a Ni-only gas diffusion cathode, with a Ni load of 0.6 mg cm−2, demonstrated a H2 production rate of 4.1 L L R − 1 d − 1 . Overall, H2 production was found to be proportional to the Ni load implying that inexpensive gas diffusion cathodes prepared by chemical deposition of Ni can be successfully used for continuous production of H2 in a MEC.

L Gilcarrera - One of the best experts on this subject based on the ideXlab platform.

  • performance of a semi pilot tubular Microbial Electrolysis Cell mec under several hydraulic retention times and applied voltages
    Bioresource Technology, 2013
    Co-Authors: L Gilcarrera, Adrián Escapa, A Moran, Begona Carracedo, X Gomez
    Abstract:

    Abstract The influence of applied voltage and hydraulic retention time on the performance of a semi-pilot modular tubular wastewater-fed Microbial Electrolysis Cell (MEC) with high scalability was investigated. A chemical oxygen demand (COD) removal efficiency of 80%, as well as an energy consumption of 0.3–1.1 Wh g-COD −1 removed, were achieved. Hydrogen production was limited by the reduced amounts of organic matter fed into the reactor, the poor performance of the cathode, and COD consuming by non electrogenic microorganisms. The presence of COD consuming microorganism that do not contribute to electrogenic metabolism severely affected the MEC performance.

  • reduced energy consumption during low strength domestic wastewater treatment in a semi pilot tubular Microbial Electrolysis Cell
    Journal of Environmental Management, 2013
    Co-Authors: L Gilcarrera, Adrián Escapa, R Moreno, A Moran
    Abstract:

    Abstract The present study examines the effect of the organic loading rate and the configuration of a semi-pilot modular Microbial Electrolysis Cell (MEC) on the energy consumption during domestic (dWW) wastewater treatment. The MEC reactor consisted of twin tubular units hydraulically connected in series and was able to reduce up to 85% of the chemical oxygen demand (COD) concentration of the influent dWW at a relatively low energy consumption (1.6 kW h kg-COD −1 ). Hydrogen production was limited by the reduced amounts of organic matter fed into the reactor and the poor performance of the cathode. Overall, the results identified both an organic loading rate (OLR) threshold that makes the use of MECs for dWW treatment feasible in terms of energy consumption and COD removal efficiency and an OLR threshold that justifies the operation of two MECs in series to provide the required degree of COD removal.

  • Microbial Electrolysis Cell scale up for combined wastewater treatment and hydrogen production
    Bioresource Technology, 2013
    Co-Authors: L Gilcarrera, P. Mehta, Adrián Escapa, S R Guiot, G Santoyo, A Moran, B Tartakovsky
    Abstract:

    Abstract This study demonstrates Microbial Electrolysis Cell (MEC) scale-up from a 50 mL to a 10 L Cell. Initially, a 50 mL membraneless MEC with a gas diffusion cathode was operated on synthetic wastewater at different organic loads. It was concluded that process scale-up might be best accomplished using a “reactor-in-series” concept. Consequently, 855 mL and 10 L MECs were built and operated. By optimizing the hydraulic retention time (HRT) of the 855 mL MEC and individually controlling the applied voltages of three anodic compartments with a real-time optimization algorithm, a COD removal of 5.7 g L R - 1 d - 1 and a hydrogen production of 1.0–2.6 L L R - 1 d - 1 was achieved. Furthermore, a two MECs in series 10 L setup was constructed and operated on municipal wastewater. This test showed a COD removal rate of 0.5 g L R - 1 d - 1 , a removal efficiency of 60–76%, and an energy consumption of 0.9 Wh per g of COD removed.

Adrián Escapa - One of the best experts on this subject based on the ideXlab platform.

  • performance of a semi pilot tubular Microbial Electrolysis Cell mec under several hydraulic retention times and applied voltages
    Bioresource Technology, 2013
    Co-Authors: L Gilcarrera, Adrián Escapa, A Moran, Begona Carracedo, X Gomez
    Abstract:

    Abstract The influence of applied voltage and hydraulic retention time on the performance of a semi-pilot modular tubular wastewater-fed Microbial Electrolysis Cell (MEC) with high scalability was investigated. A chemical oxygen demand (COD) removal efficiency of 80%, as well as an energy consumption of 0.3–1.1 Wh g-COD −1 removed, were achieved. Hydrogen production was limited by the reduced amounts of organic matter fed into the reactor, the poor performance of the cathode, and COD consuming by non electrogenic microorganisms. The presence of COD consuming microorganism that do not contribute to electrogenic metabolism severely affected the MEC performance.

  • reduced energy consumption during low strength domestic wastewater treatment in a semi pilot tubular Microbial Electrolysis Cell
    Journal of Environmental Management, 2013
    Co-Authors: L Gilcarrera, Adrián Escapa, R Moreno, A Moran
    Abstract:

    Abstract The present study examines the effect of the organic loading rate and the configuration of a semi-pilot modular Microbial Electrolysis Cell (MEC) on the energy consumption during domestic (dWW) wastewater treatment. The MEC reactor consisted of twin tubular units hydraulically connected in series and was able to reduce up to 85% of the chemical oxygen demand (COD) concentration of the influent dWW at a relatively low energy consumption (1.6 kW h kg-COD −1 ). Hydrogen production was limited by the reduced amounts of organic matter fed into the reactor and the poor performance of the cathode. Overall, the results identified both an organic loading rate (OLR) threshold that makes the use of MECs for dWW treatment feasible in terms of energy consumption and COD removal efficiency and an OLR threshold that justifies the operation of two MECs in series to provide the required degree of COD removal.

  • Microbial Electrolysis Cell scale up for combined wastewater treatment and hydrogen production
    Bioresource Technology, 2013
    Co-Authors: L Gilcarrera, P. Mehta, Adrián Escapa, S R Guiot, G Santoyo, A Moran, B Tartakovsky
    Abstract:

    Abstract This study demonstrates Microbial Electrolysis Cell (MEC) scale-up from a 50 mL to a 10 L Cell. Initially, a 50 mL membraneless MEC with a gas diffusion cathode was operated on synthetic wastewater at different organic loads. It was concluded that process scale-up might be best accomplished using a “reactor-in-series” concept. Consequently, 855 mL and 10 L MECs were built and operated. By optimizing the hydraulic retention time (HRT) of the 855 mL MEC and individually controlling the applied voltages of three anodic compartments with a real-time optimization algorithm, a COD removal of 5.7 g L R - 1 d - 1 and a hydrogen production of 1.0–2.6 L L R - 1 d - 1 was achieved. Furthermore, a two MECs in series 10 L setup was constructed and operated on municipal wastewater. This test showed a COD removal rate of 0.5 g L R - 1 d - 1 , a removal efficiency of 60–76%, and an energy consumption of 0.9 Wh per g of COD removed.

  • Optimizing the electrode size and arrangement in a Microbial Electrolysis Cell.
    Bioresource technology, 2011
    Co-Authors: L. Gil-carrera, P. Mehta, Adrián Escapa, Antonio Morán, V. García, Serge R. Guiot, Boris Tartakovsky
    Abstract:

    This study investigates the influence of anode and cathode size and arrangement on hydrogen production in a membrane-less flat-plate Microbial Electrolysis Cell (MEC). Protein measurements were used to evaluate Microbial density in the carbon felt anode. The protein concentration was observed to significantly decrease with the increase in distance from the anode–cathode interface. Cathode placement on both sides of the carbon felt anode was found to increase the current, but also led to increased losses of hydrogen to hydrogenotrophic activity leading to methane production. Overall, the best performance was obtained in the flat-plate MEC with a two-layer 10 mm thick carbon felt anode and a single gas-diffusion cathode sandwiched between the anode and the hydrogen collection compartments.

  • Multi-Population Model of a Microbial Electrolysis Cell
    Environmental science & technology, 2011
    Co-Authors: R.p. Pinto, Adrián Escapa, Bala Srinivasan, Boris Tartakovsky
    Abstract:

    This work presents a multi-population dynamic model of a Microbial Electrolysis Cell (MEC). The model describes the growth and metabolic activity of fermentative, electricigenic, methanogenic acetoclastic, and methanogenic hydrogenophilic microorganisms and is capable of simulating hydrogen production in a MEC fed with complex organic matter, such as wastewater. The model parameters were estimated with the experimental results obtained in continuous flow MECs fed with acetate or synthetic wastewater. Following successful model validation with an independent data set, the model was used to analyze and discuss the influence of applied voltage and organic load on hydrogen production and COD removal.

A Moran - One of the best experts on this subject based on the ideXlab platform.

  • performance of a semi pilot tubular Microbial Electrolysis Cell mec under several hydraulic retention times and applied voltages
    Bioresource Technology, 2013
    Co-Authors: L Gilcarrera, Adrián Escapa, A Moran, Begona Carracedo, X Gomez
    Abstract:

    Abstract The influence of applied voltage and hydraulic retention time on the performance of a semi-pilot modular tubular wastewater-fed Microbial Electrolysis Cell (MEC) with high scalability was investigated. A chemical oxygen demand (COD) removal efficiency of 80%, as well as an energy consumption of 0.3–1.1 Wh g-COD −1 removed, were achieved. Hydrogen production was limited by the reduced amounts of organic matter fed into the reactor, the poor performance of the cathode, and COD consuming by non electrogenic microorganisms. The presence of COD consuming microorganism that do not contribute to electrogenic metabolism severely affected the MEC performance.

  • reduced energy consumption during low strength domestic wastewater treatment in a semi pilot tubular Microbial Electrolysis Cell
    Journal of Environmental Management, 2013
    Co-Authors: L Gilcarrera, Adrián Escapa, R Moreno, A Moran
    Abstract:

    Abstract The present study examines the effect of the organic loading rate and the configuration of a semi-pilot modular Microbial Electrolysis Cell (MEC) on the energy consumption during domestic (dWW) wastewater treatment. The MEC reactor consisted of twin tubular units hydraulically connected in series and was able to reduce up to 85% of the chemical oxygen demand (COD) concentration of the influent dWW at a relatively low energy consumption (1.6 kW h kg-COD −1 ). Hydrogen production was limited by the reduced amounts of organic matter fed into the reactor and the poor performance of the cathode. Overall, the results identified both an organic loading rate (OLR) threshold that makes the use of MECs for dWW treatment feasible in terms of energy consumption and COD removal efficiency and an OLR threshold that justifies the operation of two MECs in series to provide the required degree of COD removal.

  • Microbial Electrolysis Cell scale up for combined wastewater treatment and hydrogen production
    Bioresource Technology, 2013
    Co-Authors: L Gilcarrera, P. Mehta, Adrián Escapa, S R Guiot, G Santoyo, A Moran, B Tartakovsky
    Abstract:

    Abstract This study demonstrates Microbial Electrolysis Cell (MEC) scale-up from a 50 mL to a 10 L Cell. Initially, a 50 mL membraneless MEC with a gas diffusion cathode was operated on synthetic wastewater at different organic loads. It was concluded that process scale-up might be best accomplished using a “reactor-in-series” concept. Consequently, 855 mL and 10 L MECs were built and operated. By optimizing the hydraulic retention time (HRT) of the 855 mL MEC and individually controlling the applied voltages of three anodic compartments with a real-time optimization algorithm, a COD removal of 5.7 g L R - 1 d - 1 and a hydrogen production of 1.0–2.6 L L R - 1 d - 1 was achieved. Furthermore, a two MECs in series 10 L setup was constructed and operated on municipal wastewater. This test showed a COD removal rate of 0.5 g L R - 1 d - 1 , a removal efficiency of 60–76%, and an energy consumption of 0.9 Wh per g of COD removed.

Bruce E. Rittmann - One of the best experts on this subject based on the ideXlab platform.

  • fermentation pre treatment of landfill leachate for enhanced electron recovery in a Microbial Electrolysis Cell
    Bioresource Technology, 2014
    Co-Authors: Mohamed Mahmoud, César I. Torres, Prathap Parameswaran, Bruce E. Rittmann
    Abstract:

    Abstract Pre-fermentation of poorly biodegradable landfill leachate (BOD 5 /COD ratio of 0.32) was evaluated for enhanced current density ( j ), Coulombic efficiency (CE), Coulombic recovery (CR), and removal of organics (BOD 5 and COD) in a Microbial Electrolysis Cell (MEC). During fermentation, the complex organic matter in the leachate was transformed to simple volatile fatty acids, particularly succinate and acetate in batch tests, but mostly acetate in semi-continuous fermentation. Carbohydrate had the highest degree of fermentation, followed by protein and lipids. j , CE, CR, and BOD 5 removal were much greater for an MEC fed with fermented leachate (23 A/m 3 or 16 mA/m 2 , 68%, 17.3%, and 83%, respectively) compared to raw leachate (2.5 A/m 3 or 1.7 mA/m 2 , 56%, 2.1%, and 5.6%, respectively). All differences support the value of pre-fermentation before an MEC for stabilization of BOD 5 and enhanced electron recovery as current when treating a recalcitrant wastewater like landfill leachate.

  • Effect of pH and Hydraulic Retention Time on Fermentation Product Distribution and Subsequent Treatment in Microbial Electrolysis Cell
    2012
    Co-Authors: Krishnan Vijayaraghavan, Hyung-sool Lee, Steve Van Ginkel, César I. Torres, Prathap Parameswaran, Chen Zhou, Bruce E. Rittmann
    Abstract:

    The objectives of this study are to examine the effect of reactor pH on fermentation product distribution using anaerobic sequencing batch reactors and to evaluate the subsequent conversion of the products to H2 in an MEC. The fermentation experiments were conducted using milk as substrate at varying fermentation pH namely 4 to 7, in order to verify the volatile fatty acid distribution.The fermented liquor served as a substrate in Microbial Electrolysis Cell.

  • significance of biological hydrogen oxidation in a continuous single chamber Microbial Electrolysis Cell
    Environmental Science & Technology, 2010
    Co-Authors: Hyung-sool Lee, Bruce E. Rittmann
    Abstract:

    A single-chamber Microbial Electrolysis Cell (MEC) that used a high density of nonmetal-catalyst carbon fibers as the anode achieved high volumetric current densities from 1470 ± 60 to 1630 ± 50 A/m3 for a hydraulic retention time of 1.6−6.5 h. The high current density was driven by a large anode surface area and corresponded to a volumetric chemical oxygen demand (COD)-removal rate of 27−49 kg COD/m3·d. Observed H2 harvesting rates were from 2.6 ± 0.10 to 4.3 ± 0.46 m3 H2/m3·d, but the H2 production rates computed from the current densities were 16.3−18.2 m3 H2/m3·d. Tracking all significant electron sinks (residual acetate, H2, CH4, biomass, and soluble Microbial products (SMP)) in the single-chamber MEC showed that H2 reoxidation by anode-respiring bacteria recycled H2 between the cathode and the anode, and this caused the large discrepancy in H2 production and harvest rates. H2 recycle accounted for 62−76% of observed current density, and this made the observed Coulombic efficiency 190−310% at steady ...

  • characterization of energy losses in an upflow single chamber Microbial Electrolysis Cell
    International Journal of Hydrogen Energy, 2010
    Co-Authors: Hyung-sool Lee, Bruce E. Rittmann
    Abstract:

    Abstract We characterized electrode energy losses and ohmic energy loss in an upflow, single-chamber Microbial Electrolysis Cell (MEC) with no metal catalyst on the cathode. The MEC produced 0.57 m 3 -H 2 /m 3 -d at an applied voltage of ∼1 V and achieved a cathodic conversion efficiency of 98% and a H 2 yield of 2.4 mol H 2 /mol acetate. Eliminating the membrane lowered the ohmic energy loss to 0.005 V, and the pH energy loss became as small as 0.072 V. The lack of metal catalyst on the cathode led to a significant cathode energy loss of 0.56 V. The anode energy loss also was relatively large at 0.395 V, but this was artificial, due to the high positive anode potential, poised at +0.07 V (vs. the standard hydrogen electrode). The energy-conversion efficiency (ECE) was 75% in the single-chamber MEC when the energy input and outputs were compared directly as electrical energy. To achieve an energy benefit out of an MEC (i.e., an ECE >100%), the applied voltage must be less than 0.6 V with a cathodic conversion efficiency over 80%. An ECE of 180% could be achieved if the anode and cathode energy losses were reduced to 0.2 V each.

  • fate of h2 in an upflow single chamber Microbial Electrolysis Cell using a metal catalyst free cathode
    Environmental Science & Technology, 2009
    Co-Authors: César I. Torres, Prathap Parameswaran, Bruce E. Rittmann
    Abstract:

    With the goal of maximizing the H2-harvesting efficiency, we designed an upflow single-chamber Microbial Electrolysis Cell (MEC) by placing the cathode on the top of the MEC and carried out a program to track the fate of H2 and electron equivalents in batch experiments. When the initial acetate concentration was 10 mM in batch-evaluation experiments lasting 32 h, the cathodic conversion efficiency (CCE) from coulombs (i.e., electron equivalents in current from the anode to the cathode) to H2 was 98 ± 2%, the Coulombic efficiency (CE) was 60 ± 1%, the H2 yield was 59 ± 2%, and methane production was negligible. However, longer batch reaction time (∼ 7 days) associated with higher initial acetate concentrations (30 or 80 mM) led to significant H2 loss due to CH4 accumulation: up to 14 ± 1% and 16 ± 2% of the biogas at 30 and 80 mM of acetate, respectively. Quantitative PCR proved that no acetoclastic methanogens were present, but that hydrogenotrophic methanogens (i.e., Methanobacteriales) were present on b...