Electricity production during wastewater treatment in a mediator-less MFC inoculated with aged anaerobic sludge (original) (raw)
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International Journal of Hydrogen Energy, 2011
A new type of microbial fuel cell (MFC), multi-anode/cathode MFC (termed as MAC MFC) containing 12 anodes/cathodes were developed to harvest electric power treating domestic wastewater. The power density of MAC MFCs increased from 300 to 380 mW/m 2 at the range of the organic loading rates (0.19e0.66 kg/m 3 /day). MAC MFCs achieved 80% of contaminant removal at the hydraulic retention time (HRT) of 20 h but the contaminant removal deceased to 66% at the HRT of 5 h. In addition, metal-doped manganese dioxide (MnO 2) cathodes were developed to replace the costly platinum cathodes, and exhibited high power density. CueMnO 2 cathodes produced 465 mW/m 2 and CoeMnO 2 cathodes produced 500 mW/m 2. Due to the cathode fouling of the precipitation of calcium and sodium, a decrease in the power density (from 400 to 150 mW/m 2) and an increase in internal resistance (R in) (from 175 to 225 U) were observed in MAC MFCs.
Bioresources and Bioprocessing, 2017
Microbial fuel cells (MFCs) are devices that exploit living microbes for electricity generation coupled to organics degradation. MFCs are expected to be applied to energy-saving wastewater treatment (WWT) as alternatives to activated-sludge reactors (ASRs). Although extensive laboratory studies have been performed to develop technologies for WWT-MFCs, limited information is available for comparative evaluation of MFCs and ASRs in terms of organics removal and waste-sludge production. In the present study, laboratory WWT experiments were performed using cassette-electrode MFCs and ASRs that were continuously supplied either with artificial domestic wastewater (ADW) containing starch and peptone or with artificial industrial wastewater (AIW) containing methanol as the major organic matter. We found that these two types of WWT reactors achieved similar organics-removal efficiencies, namely, over 93% based on chemical oxygen demands for the ADW treatment and over 97% for the AIW treatment. Sludge was routinely removed from these reactors and quantified, showing that amounts of waste sludge produced in MFCs were approximately one-third or less compared to those in ASRs. During WWT, MFCs continuously generated electricity with Coulombic efficiencies of 20% or more. In reference to ASRs, MFCs are demonstrated to be attractive WWT facilities in terms of stable organics removal and low waste-sludge production. Along with the unnecessity of electric power for aeration and the generation of power during WWT, the results obtained in the present study suggest that MFCs enable substantial energy saving during WWT.
Fuel, 2008
The possibility of bioelectricity generation from anaerobic chemical wastewater treatment was evaluated in a microbial fuel cell (MFC) [dual-chambered; mediator less anode; aerated cathode; plain graphite electrodes] employing selectively enriched hydrogen producing (acidogenic) mixed culture. Performance of MFC was evaluated at two organic/substrate loading rates (OLR) (1.165 Kg COD/m 3 -day and 1.404 Kg COD/m 3 -day) in terms of bioelectricity production and wastewater treatment at ambient pressure and temperature under acidophilic microenvironment (pH 5.5) using non-coated plain graphite electrodes (mediatorless anode; air cathode). Experimental data demonstrated the feasibility of in situ bioelectricity generation along with wastewater treatment. The performance of MFC with respect to power generation and wastewater treatment was found to depend on the applied OLR. Maximum voltage of 716 mV (2.84 mA; OLR À1.165 kg COD/m 3 -day) and 731 mV (2.97 mA; OLR-1.404 kg COD/m 3 -day) was observed at stable operating conditions. Substrate degradation rate (SDR) of 0.519 Kg COD/m 3 -day and 0.858 Kg COD/m 3 -day was observed at two OLRs studied. Maximum power yield (0.73 W/Kg COD R and 0.49 W Kg/COD R ) and current density (339.87 mA/m 2 and 355.43 mA/m 2 ) was observed at applied 50 X resistance. Fuel cell performance was evaluated employing polarization curve (100 X-30 KX), Coulombic efficiency (€ cb ) and cell potentials along with sustainable power yield at stable phase of fuel cell operation. Designed MFC configuration, adopted operating conditions and used parent inoculum showed positive response.
Biosensors and …, 2009
Function of microbial fuel cell (MFC) as bio-electrochemical treatment system in concurrence with power generation was evaluated with composite chemical wastewater at high loading conditions (18.6 g COD/l; 56.8 g TDS/l). Two dual chambered MFCs [non-catalyzed graphite electrodes; mediatorless anode] were studied separately with aerated and potassium ferricyanide catholytes under similar anodic operating conditions [mixed consortia; pH 6]. Marked improvement in power output was observed at applied higher substrate loading rate for extended period of time without any process inhibition. Catholyte nature showed significant influence on power generation [ferricyanide-651 mV; 18.22 mA; 6230 mW/kg COD R (500 ); 2321.69 mA/m 2 (100 ); 11.80 mW/m 3 and aerated-578 mV; 10.23 mA; 2450 mW/kg COD R (400 ); 1220.68 mA/m 2 (100 ); 5.64 mW/m 3 ] but not on wastewater treatment efficiency. Along with enhanced substrate degradation, relatively good removal of color (31%) and TDS (51%) was also observed during MFC operation, which might be attributed to the diverse bio-electrochemical processes triggered due to substrate metabolism and subsequent in situ bio-potential (voltage) generation. Apart from power generation, various unit operations pertaining to wastewater treatment viz., biological (anaerobic) process, electrochemical decomposition and electrochemical oxidation were found to occur symbiotically in the anode chamber. Among them anaerobic metabolism is considered to be a crucial and important rate limiting step. In view of inherent advantages, function of MFC as integrated bio-electrochemical treatment system in the direction of various wastewater treatment operations can be exploited.
Wastewater treatment and electricity generation by membrane less microbial fuel
International Journal of Environmental Engineering, 2014
Membrane less microbial fuel cell (ML-MFC) is one of the attractive approaches for the simultaneous electricity generation and wastewater treatment. In this present paper, electricity generation by ML-MFC has been studied in continuous mode. Several experiments such as effect of aeration in cathode compartment, sludge concentration, initial substrate concentration and the COD removing capability of the ML-MFC were investigated to maximise the performance. A maximum power density of 8.98mW/m 2 was observed at the current density of 34.02 mA/m 2. COD removal was detailed from 44% to 54% in all experiments.
WATER, 2021
One of the important factors in enhancing the performance of microbial fuel cells (MFCs) is reactor design and configuration. Therefore, this study was conducted to evaluate the regressors and their operating parameters affecting the double anode chamber–designed dual-chamber microbial fuel cell (DAC-DCMFC) performance. Its primary design consists of two anode chamber compartments equipped with a separator and cathode chamber. The DAC-DCMFCs were parallelly operated over 8 days (60 days after the acclimation period). They were intermittently pump-fed with the different organic loading rates (OLRs), using chemically enriched sucrose as artificial wastewater. The applied OLRs were adjusted at low, medium, and high ranges from 0.4 kg.m−3.d−1 to 2.5 kg.m−3.d−1. The reactor types were type 1 and type 2 with different cathode materials. The pH, temperature, oxidation-reduction potential (ORP), optical density 600 (OD600), chemical oxygen demand (COD), and total organic carbon (TOC) were measured, using standard analytical instruments. In general, the power production achieved a maximum of 866 ± 44 mW/m2, with a volumetric power density of 5.15 ± 0.26 W/m3 and coulombic efficiency of 84%. Two-stage COD and TOC removal at medium OLR achieved a range of 60–80%. Medium OLR is the recommended level to enhance power production and organic removal in DAC-DCMFC. The separated anode chambers into two parts in a dual anode chamber microbial fuel cell adjusted by various organic loadings expressed a preferable comprehension in the integrated MFCs for wastewater treatment.
Fuel, 2008
The possibility of bioelectricity generation from anaerobic chemical wastewater treatment was evaluated in a microbial fuel cell (MFC) [dual-chambered; mediator less anode; aerated cathode; plain graphite electrodes] employing selectively enriched hydrogen producing (acidogenic) mixed culture. Performance of MFC was evaluated at two organic/substrate loading rates (OLR) (1.165 Kg COD/m3-day and 1.404 Kg COD/m3-day) in terms of bioelectricity production and wastewater treatment at ambient pressure and temperature under acidophilic microenvironment (pH 5.5) using non-coated plain graphite electrodes (mediatorless anode; air cathode). Experimental data demonstrated the feasibility of in situ bioelectricity generation along with wastewater treatment. The performance of MFC with respect to power generation and wastewater treatment was found to depend on the applied OLR. Maximum voltage of 716 mV (2.84 mA; OLR −1.165 kg COD/m3-day) and 731 mV (2.97 mA; OLR-1.404 kg COD/m3-day) was observed at stable operating conditions. Substrate degradation rate (SDR) of 0.519 Kg COD/m3-day and 0.858 Kg COD/m3-day was observed at two OLRs studied. Maximum power yield (0.73 W/Kg CODR and 0.49 W Kg/CODR) and current density (339.87 mA/m2 and 355.43 mA/m2) was observed at applied 50 Ω resistance. Fuel cell performance was evaluated employing polarization curve (100 Ω–30 KΩ), Coulombic efficiency (€cb) and cell potentials along with sustainable power yield at stable phase of fuel cell operation. Designed MFC configuration, adopted operating conditions and used parent inoculum showed positive response.
Secondary Sludge Biodegradation and Electricity Generation in Biocathode Microbial Fuel Cells
Sewage - Recent Advances, New Perspectives and Applications [Working Title], 2021
The looking for sustainable sewage sludge management technology in the wastewater treatment plants, has brought to light the biocathode microbial fuel cells (bMFCs) which allow simultaneous biological stabilization and direct energy generation, avoiding the production of biogas. In the present study, the performance of bMFCs for the treatment of secondary sludge as anodic substrate was evaluated by analyzing the removal of organic matter, destruction of volatile solids and the generation of electrical energy under different operating conditions and applying two types of cathode chambers. The results indicated that VSS and tCOD removals up to 92% and 87% respectively can be achieved in the anodic chamber generating simultaneously energy. Current and power densities of 1.80 ± 0.09 A∙m−3 and 0.43 ± 0.02 W∙m−3 respectively were reached, showing that bMFCs are a reliable alternative to generate electricity during the sewage sludge stabilization process. It was revealed that the pH value ...
Microbial Fuel Cell (MFC) Technology for Household Waste Reduction and Bio - Energy Production
2016
MFC is a bioreactor, extracts chemical energy from organic compounds, directly as electrical energy, through microbial degradation under anaerobic conditions. The main objective of the current study is to compare the degradation ability and corresponding electric potential development from different household substrates using lab scale MFC. 50hr batch experiments were conducted with household organic rich substrates like coconut water, rice starch and milk. Different concentrations of KMnO 4were used as oxidizing agent in the cathode chamber. A voltage of about 300to 700mV was produced from 125ml of substrates seeded with cow dung. Coconut water and starch produced electric potential with the support of oxidizing agent KMnO 4, where as the potential produced by milk found to be independent of the KMnO 4concentration. The maximum electric potential developed was 762mV from coconut water at 1500mg/l KMnO 4with a COD reduction of 22%.