1
|
Mathuriya AS. Development of trickling bio-electrochemical reactor (TrickBER) for large scale energy efficient wastewater treatment. ENVIRONMENTAL TECHNOLOGY 2022; 43:550-559. [PMID: 32674685 DOI: 10.1080/09593330.2020.1797893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Accepted: 07/08/2020] [Indexed: 06/11/2023]
Abstract
Bioelectrochemical systems such as microbial fuel cells are novel systems; those directly transform the chemical energy contained in organics of wastewater into electrical energy by the metabolic action of the microbial community. During the last two decades, bioelectrochemical systems astonishingly increased their wastewater treatment capabilities, sustainability, and power output. However, studies on scalable architectural designs of bioelectrochemical systems received less attention. Lower power yield and high cost are two major limitations for scaling up of bioelectrochemical systems. This study reports a low cost, scalable, air cathode bio-electrochemical reactor, constructed by adopting a trickling filtration approach (TrickBER) and operated in continuous mode. Various facets of construction, installation, and operation of TrickBER were investigated and optimized to achieve an efficient performance. TrickBER was found suitable in simultaneous electricity generation during continuous wastewater treatment and, in the future, could be used in small/cottage industries.
Collapse
Affiliation(s)
- Abhilasha Singh Mathuriya
- Department of Life Sciences, School of Basic Sciences and Research, Sharda University Greater Noida- 201306, India
- Department of Biotechnology, Anand Engineering College, Keetham
| |
Collapse
|
2
|
Hoang AT, Nižetić S, Ng KH, Papadopoulos AM, Le AT, Kumar S, Hadiyanto H, Pham VV. Microbial fuel cells for bioelectricity production from waste as sustainable prospect of future energy sector. CHEMOSPHERE 2022; 287:132285. [PMID: 34563769 DOI: 10.1016/j.chemosphere.2021.132285] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/23/2021] [Accepted: 09/16/2021] [Indexed: 06/13/2023]
Abstract
Microbial fuel cell (MFC) is lauded for its potentials to solve both energy crisis and environmental pollution. Technologically, it offers the capability to harness electricity from the chemical energy stored in the organic substrate with no intermediate steps, thereby minimizes the entropic loss due to the inter-conversion of energy. The sciences underneath such MFCs include the electron and proton generation from the metabolic decomposition of the substrate by microbes at the anode, followed by the shuttling of these charges to cathode for electricity generation. While its promising prospects were mutually evinced in the past investigations, the upscaling of MFC in sustaining global energy demands and waste treatments is yet to be put into practice. In this context, the current review summarizes the important knowledge and applications of MFCs, concurrently identifies the technological bottlenecks that restricted its vast implementation. In addition, economic analysis was also performed to provide multiangle perspectives to readers. Succinctly, MFCs are mainly hindered by the slow metabolic kinetics, sluggish transfer of charged particles, and low economic competitiveness when compared to conventional technologies. From these hindering factors, insightful strategies for improved practicality of MFCs were formulated, with potential future research direction being identified too. With proper planning, we are delighted to see the industrialization of MFCs in the near future, which would benefit the entire human race with cleaner energy and the environment.
Collapse
Affiliation(s)
- Anh Tuan Hoang
- Institute of Engineering, Ho Chi Minh City University of Technology (HUTECH), Ho Chi Minh City, Viet Nam.
| | - Sandro Nižetić
- University of Split, FESB, Rudjera Boskovica 32, 21000, Split, Croatia
| | - Kim Hoong Ng
- Department of Chemical Engineering, Ming Chi University of Technology, New Taipei City, 24301, Taiwan.
| | - Agis M Papadopoulos
- Process Equipment Design Laboratory, Department of Mechanical Engineering, Aristotle University of Thessaloniki, Postal Address: GR-54124, Thessaloniki, Greece
| | - Anh Tuan Le
- School of Transportation Engineering, Hanoi University of Science and Technology, Hanoi, Viet Nam.
| | - Sunil Kumar
- Waste Reprocessing Division, CSIR-National Environmental Engineering Research Institute, Nagpur, 440 020, India
| | - H Hadiyanto
- Center of Biomass and Renewable Energy (CBIORE), Department of Chemical Engineering, Diponegoro University, Jl. Prof. Soedarto SH, Tembalang, Semarang, 50271, Indonesia; School of Postgraduate Studies, Diponegoro University, Jl. Imam Bardjo, SH Semarang, 50241, Indonesia.
| | - Van Viet Pham
- PATET Research Group, Ho Chi Minh City University of Transport, Ho Chi Minh City, Viet Nam.
| |
Collapse
|
3
|
Bagchi S, Behera M. Evaluation of the effect of anolyte recirculation and anolyte pH on the performance of a microbial fuel cell employing ceramic separator. Process Biochem 2021. [DOI: 10.1016/j.procbio.2021.01.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
|
4
|
Li L, Jiang B, Tang D, Zhang X, Yuan K, Zhang Q. Alkaline treatment of used carbon-brush anodes for restoring power generation of microbial fuel cells. RSC Adv 2018; 8:36754-36760. [PMID: 35558927 PMCID: PMC9088807 DOI: 10.1039/c8ra07216g] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Accepted: 10/03/2018] [Indexed: 11/27/2022] Open
Abstract
Long-term operation of microbial fuel cells (MFCs) results in an electrochemical activity decline by the degradation of the anodic biofilm. In this work, an alkaline soaking treatment is proposed as an efficient and simple method for anode regeneration. The alkaline treatment was employed in a used carbon-brush anode, and its performance was compared with those of two other traditional treatment methods, i.e. air drying and carbonization. Among all the treated MFC anodes, the one treated by alkaline soaking exhibited the highest recovery rate. A series of tests including a start-up process, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and MFC performance were performed. The results show that alkaline soaking can modify the carbon fiber by introducing carboxyl groups onto the carbon surface and completely remove the aged biofilm, demonstrating that the alkaline treatment of used anodes is a practically effective method for the performance recovery of MFCs. An alkaline soaking treatment is proposed as an efficient and simple method for anode regeneration.![]()
Collapse
Affiliation(s)
- Lin Li
- Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, Dalian University of Technology Dalian 116024 China
| | - Bo Jiang
- Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, Dalian University of Technology Dalian 116024 China
| | - Dawei Tang
- Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, Dalian University of Technology Dalian 116024 China
| | - Xiaoliang Zhang
- Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, Dalian University of Technology Dalian 116024 China
| | - Kunpeng Yuan
- Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, Dalian University of Technology Dalian 116024 China
| | - Qian Zhang
- Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, Dalian University of Technology Dalian 116024 China
| |
Collapse
|
5
|
Luo S, Sai Shankar Sampara P, He Z. Effective algal harvesting by using mesh membrane for enhanced energy recovery in an innovative integrated photobioelectrochemical system. BIORESOURCE TECHNOLOGY 2018; 253:33-40. [PMID: 29328932 DOI: 10.1016/j.biortech.2018.01.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 12/29/2017] [Accepted: 01/01/2018] [Indexed: 06/07/2023]
Abstract
In this work, an innovative design of integrated photobioelectrochemcial system (IPB) and an algal harvesting method based on polyester-mesh membrane (MM) were investigated. The algal growth/harvesting period of 6 days led to the highest surface biomass productivity (SBP) of 0.88 g m-2 day-1 and the highest energy generation of 0.157 ± 0.001 kJ day-1. The harvesting frequency of 3 times in an operational cycle (with three pieces of MM) enhanced the SBP to 1.14 g m-2 day-1. The catholyte recirculation for catholyte mixing resulted in a positive net energy production (NEP) of 0.227 ± 0.025 kJ day-1. Those results have demonstrated the benefits of both using mesh membrane and the new reactor design for algal collection with positive effects on improving IPB performance.
Collapse
Affiliation(s)
- Shuai Luo
- Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Pranav Sai Shankar Sampara
- Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Zhen He
- Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA.
| |
Collapse
|
6
|
Zou S, He Z. Efficiently "pumping out" value-added resources from wastewater by bioelectrochemical systems: A review from energy perspectives. WATER RESEARCH 2018; 131:62-73. [PMID: 29274548 DOI: 10.1016/j.watres.2017.12.026] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2017] [Revised: 12/11/2017] [Accepted: 12/12/2017] [Indexed: 06/07/2023]
Abstract
Bioelectrochemical systems (BES) can accomplish simultaneous wastewater treatment and resource recovery via interactions between microbes and electrodes. Often deemed as "energy efficient" technologies, BES have not been well evaluated for their energy performance, such as energy production and consumption. In this work, we have conducted a review and analysis of energy balance in BES with parameters like normalized energy recovery, specific energy consumption, and net energy production. Several BES representatives based on their functions were selected for analysis, including direct electricity generation in microbial fuel cells, hydrogen production in microbial electrolysis cells, nitrogen recovery in BES, chemical production in microbial electrosynthesis cells, and desalination in microbial desalination cells. Energy performance was normalized to water volume (kWh m-3), organic removal (kWh kg COD-1), nitrogen recovery (kWh kg N-1), chemical production (kWh kg-1), or removed salt during desalination (kWh kg-1). The key operating factors such as pumping system (recirculation/feeding pumps) and external power supply were discussed for their effects on energy performance. This is an in-depth analysis of energy performance of various BES and expected to encourage more thinking, analysis, and presentation of energy data towards appropriate research and development of BES technology for resource recovery from wastewater.
Collapse
Affiliation(s)
- Shiqiang Zou
- Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24061, USA
| | - Zhen He
- Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24061, USA.
| |
Collapse
|
7
|
|
8
|
Li J, Hu L, Zhang L, Ye DD, Zhu X, Liao Q. Uneven biofilm and current distribution in three-dimensional macroporous anodes of bio-electrochemical systems composed of graphite electrode arrays. BIORESOURCE TECHNOLOGY 2017; 228:25-30. [PMID: 28056366 DOI: 10.1016/j.biortech.2016.12.092] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 12/20/2016] [Accepted: 12/22/2016] [Indexed: 06/06/2023]
Abstract
A 3-D macroporous anode was constructed using different numbers of graphite rod arrays in fixed-volume bio-electrochemical systems (BESs), and the current and biofilm distribution were investigated by dividing the 3-D anode into several subunits. In the fixed-volume chamber, current production was not significantly improved after the electrode number increased to 36. In the case of 100 electrodes, a significant uneven current distribution was found in the macroporous anode. This was attributed to a differential pH distribution, which resulted from proton accumulation inside the macroporous anode. The pH distribution influenced the biofilm development and led to an uneven biofilm distribution. With respect to current generation, the uneven distribution of both the pH and biofilm contributed to the uneven current distribution. The center had a low pH, which led to less biofilm and a lower contribution to the total current, limiting the performance of the BESs.
Collapse
Affiliation(s)
- Jun Li
- Key Laboratory of Low-Grade Energy Utilization Technologies and Systems, Chongqing University, Ministry of Education, Chongqing 40003, China; Institute of Engineering Thermophysics, Chongqing University, Chongqing 400030, China
| | - Linbin Hu
- Key Laboratory of Low-Grade Energy Utilization Technologies and Systems, Chongqing University, Ministry of Education, Chongqing 40003, China; Institute of Engineering Thermophysics, Chongqing University, Chongqing 400030, China
| | - Liang Zhang
- Key Laboratory of Low-Grade Energy Utilization Technologies and Systems, Chongqing University, Ministry of Education, Chongqing 40003, China; Institute of Engineering Thermophysics, Chongqing University, Chongqing 400030, China.
| | - Ding-Ding Ye
- Key Laboratory of Low-Grade Energy Utilization Technologies and Systems, Chongqing University, Ministry of Education, Chongqing 40003, China; Institute of Engineering Thermophysics, Chongqing University, Chongqing 400030, China
| | - Xun Zhu
- Key Laboratory of Low-Grade Energy Utilization Technologies and Systems, Chongqing University, Ministry of Education, Chongqing 40003, China; Institute of Engineering Thermophysics, Chongqing University, Chongqing 400030, China
| | - Qiang Liao
- Key Laboratory of Low-Grade Energy Utilization Technologies and Systems, Chongqing University, Ministry of Education, Chongqing 40003, China; Institute of Engineering Thermophysics, Chongqing University, Chongqing 400030, China
| |
Collapse
|
9
|
Koroglu EO, Cetinkaya AY, Ozkaya B, Demir A. Simultaneous production of bioelectricity and treatment of membrane concentrate in multitube microbial fuel cell. J Biosci Bioeng 2016; 122:594-600. [DOI: 10.1016/j.jbiosc.2016.04.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2015] [Revised: 04/07/2016] [Accepted: 04/08/2016] [Indexed: 10/21/2022]
|
10
|
Kong F, Wang A, Ren HY. Optimized matching modes of bioelectrochemical module and anaerobic sludge in the integrated system for azo dye treatment. BIORESOURCE TECHNOLOGY 2015; 192:486-493. [PMID: 26080106 DOI: 10.1016/j.biortech.2015.06.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Revised: 05/29/2015] [Accepted: 06/01/2015] [Indexed: 06/04/2023]
Abstract
In this work, three matching modes (relative positions, catholyte flow sequences, and flow regimes) of bioelectrochemical module and anaerobic sludge were evaluated and optimized for azo dye treatment in the integrated system with embedding modular bioelectrochemical system into anaerobic sludge reactor. Results showed that it was favorable to operate this integrated system under the condition of 1/4 cathode soaking into sludge with spiral distributor in down-flow direction. Current, electrochemical impedance spectroscopy and pH clearly demonstrated the important role of 1/4 soaking in electron/proton transfer. The down-flow direction flowed through electrode zone and then sludge zone could benefit to the efficient use of cathode and improve AO7 treatment. Furthermore, the positive effect of spiral catholyte distributor might be due to its promoting role in mixing and creating a spiral flow channel around the cathode electrode-microbes-solution interface. These results exhibited great potential for matching modular bioelectrochemical system with anaerobic treatment process.
Collapse
Affiliation(s)
- Fanying Kong
- State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China.
| | - Aijie Wang
- State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China; Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| | - Hong-Yu Ren
- State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China.
| |
Collapse
|
11
|
Increased performance of a tubular microbial fuel cell with a rotating carbon-brush anode. Biosens Bioelectron 2015; 63:558-561. [DOI: 10.1016/j.bios.2014.08.014] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Accepted: 08/11/2014] [Indexed: 11/22/2022]
|
12
|
Michie IS, Kim JR, Dinsdale RM, Guwy AJ, Premier GC. The influence of anodic helical design on fluid flow and bioelectrochemical performance. BIORESOURCE TECHNOLOGY 2014; 165:13-20. [PMID: 24726135 DOI: 10.1016/j.biortech.2014.03.069] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Revised: 03/12/2014] [Accepted: 03/15/2014] [Indexed: 06/03/2023]
Abstract
In this study three different tubular helical anode designs are compared, for each helical design the pitch and nominal sectional area/liquid flow channel between the helicoids was varied and this produced maximum power densities of 11.63, 9.2 and 6.73Wm(-3) (small, medium and large helical flow channel cross-sections). It is found that the level of mixing and the associated shear rates present in the anodes affects both the power development and biofilm formation. The small helical flow channel carbon anode produced 40% more biofilm and this result was related to modelling data which determined a system shear rate of 237s(-1), compared to 52s(-1) and 47s(-1) for the other reactor configurations. The results from computational fluid dynamic modelling further distinguishes between convective flow conditions and supports the influence of helical structure on system performance, so establishing the importance of anodic design on the overall electrogenic biofilm activity.
Collapse
Affiliation(s)
- Iain S Michie
- Sustainable Environment Research Centre (SERC), Faculty of Computing, Engineering and Science, University of South Wales, Pontypridd, Mid-Glamorgan CF37 1DL, UK.
| | - Jung Rae Kim
- School of Chemical and Biomolecular Engineering, Pusan National University (PNU), Republic of Korea
| | - Richard M Dinsdale
- Sustainable Environment Research Centre (SERC), Faculty of Computing, Engineering and Science, University of South Wales, Pontypridd, Mid-Glamorgan CF37 1DL, UK
| | - Alan J Guwy
- Sustainable Environment Research Centre (SERC), Faculty of Computing, Engineering and Science, University of South Wales, Pontypridd, Mid-Glamorgan CF37 1DL, UK
| | - Giuliano C Premier
- Sustainable Environment Research Centre (SERC), Faculty of Computing, Engineering and Science, University of South Wales, Pontypridd, Mid-Glamorgan CF37 1DL, UK
| |
Collapse
|
13
|
Ieropoulos IA, Ledezma P, Stinchcombe A, Papaharalabos G, Melhuish C, Greenman J. Waste to real energy: the first MFC powered mobile phone. Phys Chem Chem Phys 2014; 15:15312-6. [PMID: 23939246 DOI: 10.1039/c3cp52889h] [Citation(s) in RCA: 135] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This communication reports for the first time the charging of a commercially available mobile phone, using Microbial Fuel Cells (MFCs) fed with real neat urine. The membrane-less MFCs were made out of ceramic material and employed plain carbon based electrodes.
Collapse
Affiliation(s)
- Ioannis A Ieropoulos
- Bristol Robotics Laboratory, Faculty of Environment & Technology, University of the West of England, BS16 1QY, Bristol, UK.
| | | | | | | | | | | |
Collapse
|
14
|
Tong Y, He Z. Current-driven nitrate migration out of groundwater by using a bioelectrochemical system. RSC Adv 2014. [DOI: 10.1039/c3ra47851c] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
|
15
|
Wang H, Wang G, Ling Y, Qian F, Song Y, Lu X, Chen S, Tong Y, Li Y. High power density microbial fuel cell with flexible 3D graphene-nickel foam as anode. NANOSCALE 2013; 5:10283-90. [PMID: 24057049 DOI: 10.1039/c3nr03487a] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The structure and electrical conductivity of anode play a significant role in the power generation of microbial fuel cells (MFCs). In this study, we developed a three-dimensional (3D) reduced graphene oxide-nickel (denoted as rGO-Ni) foam as an anode for MFC through controlled deposition of rGO sheets onto the nickel foam substrate. The loading amount of rGO sheets and electrode surface area can be controlled by the number of rGO loading cycles. 3D rGO-Ni foam anode provides not only a large accessible surface area for microbial colonization and electron mediators, but also a uniform macro-porous scaffold for effective mass diffusion of the culture medium. Significantly, at a steady state of the power generation, the MFC device with flexible rGO-Ni electrodes produced an optimal volumetric power density of 661 W m(-3) calculated based on the volume of anode material, or 27 W m(-3) based on the volume of the anode chamber. These values are substantially higher than that of plain nickel foam, and other conventional carbon based electrodes (e.g., carbon cloth, carbon felt, and carbon paper) measured in the same conditions. To our knowledge, this is the highest volumetric power density reported for mL-scale MFC device with a pure strain of Shewanella oneidensis MR-1. We also demonstrated that the MFC device can be operated effectively in a batch-mode at least for a week. These new 3D rGO-Ni electrodes show great promise for improving the power generation of MFC devices.
Collapse
Affiliation(s)
- Hanyu Wang
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, California 95064, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Zhang F, Ge Z, Grimaud J, Hurst J, He Z. Long-term performance of liter-scale microbial fuel cells treating primary effluent installed in a municipal wastewater treatment facility. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:4941-8. [PMID: 23517192 DOI: 10.1021/es400631r] [Citation(s) in RCA: 128] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Two 4 L tubular microbial fuel cells (MFCs) were installed in a municipal wastewater treatment facility and operated for more than 400 days on primary effluents. Both MFCs removed 65-70% chemical oxygen demand (COD) at a hydraulic retention time (HRT) of 11 h and reduced about 50% suspended solids. The COD removal rates were about 0.4 (total) or 0.2 (soluble) kg m(-3) day(-1). They could handle fluctuation, such as emptying the anode for 1-3 days or different HRTs. The preliminary analysis of energy production and consumption indicated that the two MFCs could theoretically achieve a positive energy balance and energy consumption could be reduced using larger tubing connectors. Through linkage to a denitrifying MFC, the MFC system improved the removal of total nitrogen from 27.1 to 76.2%; however, the energy production substantially decreased because of organic consumption in the denitrifying MFC. Establishing a carbon (electron) balance revealed that sulfate reduction was a major electron scavenger (37-64%) and methane production played a very minor role (1.3-3.3%) in electron distribution. These results demonstrate the technical viability of MFC technology outside the laboratory and its potential advantages in low energy consumption, low sludge production, and energy recovery from wastes.
Collapse
Affiliation(s)
- Fei Zhang
- Department of Civil Engineering and Mechanics, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53211, USA
| | | | | | | | | |
Collapse
|