Crude petroleum pollution causes some serious ecological disasters in the ocean.Marine sediment microbial fuel cells(MSMFCs)have been utilized as a novel method for in-situ degradation and a long-term power source.Her...Crude petroleum pollution causes some serious ecological disasters in the ocean.Marine sediment microbial fuel cells(MSMFCs)have been utilized as a novel method for in-situ degradation and a long-term power source.Herein,the effect of different concentrations of rhamnolipids biosurfactant on the electrochemical performance of MSMFCs anode and the higher efficiency of oil degradation are creatively investigated.The results indicate that the anode in sediment containing rhamnolipids effectively enriches the indigenous electrogenic Pseudophaeobacter and Pseudomonas,which significantly enhances the electrochemical performance of the MSMFCs.Under rhamnolipids at the concentration of 200 mg kg^(-1)in sediment,the anode specific capacitance(401.45 Fm^(-2)),exchange current density(4.87×10^(-2)mAm^(-2)),and cell maximum power density(140.24 mWm^(-2))increase by 2.50,38.65,and 2.11 times,respectively,in comparison with its natural sediment.And the oil degradation rate(40.06%)was higher than the blank(17.55%).It demonstrates that the synergistic effect between electrochemical catalytic degradation and emulsifying solubilization of rhamnolipids surfactant directly accelerates the degradation of petroleum in marine sediment,which will provide a novel method and theoretical guidance for in-situ degradation and efficient removal of crude petroleum on ocean floor.展开更多
Cathode activity plays an important role in the improvement of the microbial fuel cells on ocean floor （BMFCs）. A comparison study between Rayon-based （CF-R） and PAN-based carbon fiber （CF-P） cathodes is conduct...Cathode activity plays an important role in the improvement of the microbial fuel cells on ocean floor （BMFCs）. A comparison study between Rayon-based （CF-R） and PAN-based carbon fiber （CF-P） cathodes is conducted in the paper. The two carbon fibers were heat treated to improve cell performance （CF-R-H ＆ CF-P-H）, and were used to build a new BMFCs structure with a foamy carbon anode. The maximum power density was 112.4mWm-2 for CF-R-H, followed by 66.6mWm-2 for CF-R, 49.7 mWm-2 for CF-P-H and 21.6mWm-2 for CF-P respectively. The higher specific area and deep groove make CF-R have a better power output than with CF-P. Meanwhile, heat treatment of carbon fiber can improve cell power, nearly two-fold higher than heat treatment of plain fiber. This improvement may be due to the quinones group formation to accelerate the reduction of oxygen and electron transfer on the fiber surface in the three phase boundary after heat treatment. Compared to PAN-based carbon fiber, Rayon-based carbon fiber would be preferentially selected as cathode in novel BMFCs design due to its high surface area, low cost and higher power. The comparison research is significant for cathode material selection and cell design.展开更多
Electrode materials have an important effect on the property of microbial fuel cell(MFC). Carbon foam is utilized as an anode and further modified by urea to improve its performance in marine benthic microbial fuel ce...Electrode materials have an important effect on the property of microbial fuel cell(MFC). Carbon foam is utilized as an anode and further modified by urea to improve its performance in marine benthic microbial fuel cell(BMFC) with higher voltage and output power. The electrochemical properties of plain carbon foam(PC) and urea-modified carbon foam(UC) are measured respectively. Results show that the UC obtains better wettability after its modification and higher anti-polarization ability than the PC. A novel phenomenon has been found that the electrical potential of the modified UC anode is nearly 100 m V lower than that of the PC, reaching-570 ±10 m V(vs. SCE), and that it also has a much higher electron transfer kinetic activity, reaching 9399.4 m W m-2, which is 566.2-fold higher than that from plain graphite anode(PG). The fuel cell containing the UC anode has the maximum power density(256.0 m W m-2) among the three different BMFCs. Urea would enhance the bacteria biofilm formation with a more diverse microbial community and maintain more electrons, leading to a lower anodic redox potential and higher power output. The paper primarily analyzes why the electrical potential of the modified anode becomes much lower than that of others after urea modification. These results can be utilized to construct a novel BMFC with higher output power and to design the conditioner of voltage booster with a higher conversion ratio. Finally, the carbon foam with a bigger pore size would be a potential anodic material in conventional MFC.展开更多
Marine sediment microbial fuel cell(MSMFCs)can be utilized as a long lasting power source to drive small instruments to work for long time on ocean floor and its higher power has a significant meaning for practical ap...Marine sediment microbial fuel cell(MSMFCs)can be utilized as a long lasting power source to drive small instruments to work for long time on ocean floor and its higher power has a significant meaning for practical application.Anode modification can greatly improve the performance of MSMFCs.Herein,humic acid(HA)and humic acid-iron ion complex(HA-Fe)were used to modify the anode for constructing a better MSMFCs.The results indicated that HA-Fe modified anode,better than HA modification,significantly improved the MSMFCs cell power output.The maximum power density of HA-Fe modified MSMFCs is 165.3 mW m−2,which are 6.5-folds of blank MSMFCs.The number of microorganisms on anode,redox activity,and relative kinetic activity were 1.8-,6.1-,and 13.1-folds of blank MSMFCs,respectively.The MSMFCs improvement would be attributed to the electron transfer media of HA and the valence conversion of Fe ions.A synergistic interaction between the naturally occurring HA and Fe ions on the anodic surface in marine sediments would make the modified anodes have‘renewable’characteristics,which is beneficial for the MSMFCs to maintain its long-term higher power.展开更多
Microbial fuel cell(MFC) on the ocean floor is a kind of novel energy-harvesting device that can be developed to drive small instruments to work continuously.The shape of electrode has a great effect on the performanc...Microbial fuel cell(MFC) on the ocean floor is a kind of novel energy-harvesting device that can be developed to drive small instruments to work continuously.The shape of electrode has a great effect on the performance of the MFC.In this paper,several shapes of electrode and cell structure were designed,and their performance in MFC were compared in pairs:Mesh(cell-1) vs.flat plate(cell-2),branch(cell-3) vs.cylinder(cell-4),and forest(cell-5) vs.disk(cell-6) FC.Our results showed that the maximum power densities were 16.50,14.20,19.30,15.00,14.64,and 9.95 mWm-2 for cell-1,2,3,4,5 and 6 respectively.And the corre-sponding diffusion-limited currents were 7.16,2.80,18.86,10.50,18.00,and 6.900 mA.The mesh and branch anodes showed higher power densities and much higher diffusion-limited currents than the flat plate and the cylinder anodes respectively due to the low diffusion hindrance with the former anodes.The forest cathode improved by 47% of the power density and by 161% of diffusion-limited current than the disk cathode due to the former's extended solid/liquid/gas three-phase boundary.These results indicated that the shape of electrode is a major parameter that determining the diffusion-limited current of an MFC,and the differences in the elec-trode shape lead to the differences in cell performance.These results would be useful for MFC structure design in practical applica-tions.展开更多
Improving the performance of anode is a crucial step for increasing output power of marine sediment microbial fuel cells(MSMFCs)to drive marine monitor to work for a long term on the ocean floor.A pyrolyzed iron phtha...Improving the performance of anode is a crucial step for increasing output power of marine sediment microbial fuel cells(MSMFCs)to drive marine monitor to work for a long term on the ocean floor.A pyrolyzed iron phthalocyanine modified multi-walled carbon nanotubes composite(FePc/MWCNTs)has been utilized as a novel nodified anode in the MSMFC.Its structure of the composite modified anode and electrochemical performance have been investigated respectively in the paper.There is a substantial improvement in electron-transfer efficiency from the bacteria biofilm to the modified anode via the pyrolyzed FePc/MWCNTs composite based on their cyclic voltammetry(CV)and Tafel curves.The electron transfer kinetic activity of the FePc/MWCNTs-modified anode is 1.86 times higher than of the unmodified anode.The maximum power density of the modified MSMFC was 572.3±14 m W m^-2,which is 2.6 times larger than the unmodified one(218.3±11 m W m^-2).The anodic structure and cell scale would be greatly minimized to obtain the same output power by the modified MSMFC,so that it will make the MSMFC to be easily deployed on the remote ocean floor.Therefore,it would have a great significance for us to design a novel and renewable long term power source.Finally,a novel molecular synergetic mechanism is proposed to elucidate its excellent electrochemical performance.展开更多
The electrochemical performances of cathode play a key role in the marine sediment microbial fuel cells(MSMFCs)as a long lasting power source to drive instruments,especially when the dissolved oxygen concentration is ...The electrochemical performances of cathode play a key role in the marine sediment microbial fuel cells(MSMFCs)as a long lasting power source to drive instruments,especially when the dissolved oxygen concentration is very low in seawater.A CTS-Fe^(3+)modified cathode is prepared here by grafting chitosan(CTS)on a carbon fiber surface and then chelating Fe^(3+)through the coordination process.The electrochemical performance in seawater and the output power of the assembled MSMFCs are both studied.The results show that the exchange current densities of CTS and the CTS-Fe^(3+)group are 5.5 and 6.2 times higher than that of the blank group,respectively.The potential of the CTS-Fe^(3+)modified cathode increases by 138 mV.The output power of the fuel cell(613.0 mW m^(-2))assembled with CTS-Fe^(3+)is 54 times larger than that of the blank group(11.4 mW m^(-2))and the current output corresponding with the maximum power output also increases by 56 times.Due to the valence conversion between Fe^(3+)and Fe^(2+)on the modified cathode,the kinetic activity of the dissolved oxygen reduction is accelerated and the depolarization capability of the cathode is enhanced,resulting higher cell power.On the basis of this study,the new cathode materials will be encouraged to design with the complex of iron ion in natural seawater as the catalysis for oxygen reduction to improve the cell power in deep sea.展开更多
Anode modification plays a key role in higher power output in marine sediment microbial fuel cells(MSMFCs).A low-molecular organosilicon compound(3-aminopropyltriethoxysilane)was grafted onto the surface of carbon fel...Anode modification plays a key role in higher power output in marine sediment microbial fuel cells(MSMFCs).A low-molecular organosilicon compound(3-aminopropyltriethoxysilane)was grafted onto the surface of carbon felt using chemical method and a composite modified anode was prepared through organic ligands coordination Fe^(3+)for better electro-chemical per-formance.Results show that the biofilm resistance of the composite modified anode(2707Ω)is 1.3 times greater than that of the unmodified anode(2100Ω),and its biofilm capacitance also increases by 2.2 times,indicating that the composite modification pro-motes the growth and attachment of electroactive bacteria on the anode.Its specific capacitance(887.8 Fm^(−2))is 3.7 times higher than that of unmodified anode,generating a maximum current density of 1.5Am^(−2).In their Tafel curves,the composite modified anodic exchange current density(5.25×10^(−6)Acm^(−2))is 5.8 times bigger than that of unmodified anode,which suggests that the electro-chemical activity of redox,anti-polarization ability and electron transfer kinetic activity are significantly enhanced.The marine sediment microbial fuel cell with the composite modified anode generates the higher power densities than the blank(203.8mWm^(−2) versus 45.07mWm^(−2)),and its current also increases by 4.4 times.The free amino groups on the anode surface expands a creative idea that the modified anode ligates the natural Fe(Ⅲ)ion in sea water in the MSMFCs for its higher power output.展开更多
基于实际工程,借助电磁暂态仿真软件EMTP-RV,建立了广西灵川县灵田风电场的详细仿真模型及与风电场接入同一变电站110 k V母线的灵川电铁牵引站及机车负荷模型。研究了风电场在不同风速出力和电铁负荷状态下公共接入点电能质量,以及风...基于实际工程,借助电磁暂态仿真软件EMTP-RV,建立了广西灵川县灵田风电场的详细仿真模型及与风电场接入同一变电站110 k V母线的灵川电铁牵引站及机车负荷模型。研究了风电场在不同风速出力和电铁负荷状态下公共接入点电能质量,以及风电场与电铁牵引负荷接入同一110 k V母线的相互影响。并开发了电能质量计算模板用于多种电能质量指标的计算。多种运行工况的仿真表明,风电场与电铁负荷接入同一母线会恶化电网的运行条件,导致公共接入点剧烈电压波动,并向公共电网注入大量谐波。针对仿真中揭示的电压波动与功率振荡现象,结合现场条件,针对性提出合理调度风电出力、谐波治理与无功补偿等多项改善措施,使接入点的电能质量满足国家标准。展开更多
基金financially supported by the National Natural Science Foundation of China(No.22075262)。
文摘Crude petroleum pollution causes some serious ecological disasters in the ocean.Marine sediment microbial fuel cells(MSMFCs)have been utilized as a novel method for in-situ degradation and a long-term power source.Herein,the effect of different concentrations of rhamnolipids biosurfactant on the electrochemical performance of MSMFCs anode and the higher efficiency of oil degradation are creatively investigated.The results indicate that the anode in sediment containing rhamnolipids effectively enriches the indigenous electrogenic Pseudophaeobacter and Pseudomonas,which significantly enhances the electrochemical performance of the MSMFCs.Under rhamnolipids at the concentration of 200 mg kg^(-1)in sediment,the anode specific capacitance(401.45 Fm^(-2)),exchange current density(4.87×10^(-2)mAm^(-2)),and cell maximum power density(140.24 mWm^(-2))increase by 2.50,38.65,and 2.11 times,respectively,in comparison with its natural sediment.And the oil degradation rate(40.06%)was higher than the blank(17.55%).It demonstrates that the synergistic effect between electrochemical catalytic degradation and emulsifying solubilization of rhamnolipids surfactant directly accelerates the degradation of petroleum in marine sediment,which will provide a novel method and theoretical guidance for in-situ degradation and efficient removal of crude petroleum on ocean floor.
基金support by the Key Project of Nature Science Fund of Shandong Province, China (ZR2011B Z008)the Special Fund of Marine Renewable Energy from China’s State Oceanic Administration (GHME 2011GD04)
文摘Cathode activity plays an important role in the improvement of the microbial fuel cells on ocean floor （BMFCs）. A comparison study between Rayon-based （CF-R） and PAN-based carbon fiber （CF-P） cathodes is conducted in the paper. The two carbon fibers were heat treated to improve cell performance （CF-R-H ＆ CF-P-H）, and were used to build a new BMFCs structure with a foamy carbon anode. The maximum power density was 112.4mWm-2 for CF-R-H, followed by 66.6mWm-2 for CF-R, 49.7 mWm-2 for CF-P-H and 21.6mWm-2 for CF-P respectively. The higher specific area and deep groove make CF-R have a better power output than with CF-P. Meanwhile, heat treatment of carbon fiber can improve cell power, nearly two-fold higher than heat treatment of plain fiber. This improvement may be due to the quinones group formation to accelerate the reduction of oxygen and electron transfer on the fiber surface in the three phase boundary after heat treatment. Compared to PAN-based carbon fiber, Rayon-based carbon fiber would be preferentially selected as cathode in novel BMFCs design due to its high surface area, low cost and higher power. The comparison research is significant for cathode material selection and cell design.
基金supported by the Key Project of Natural Science Fund of Shandong Province,China(ZR2011 BZ008)the Special Fund of Marine Renewable Energy from State Ocean Bureau,China(GHME2011GD 04)
文摘Electrode materials have an important effect on the property of microbial fuel cell(MFC). Carbon foam is utilized as an anode and further modified by urea to improve its performance in marine benthic microbial fuel cell(BMFC) with higher voltage and output power. The electrochemical properties of plain carbon foam(PC) and urea-modified carbon foam(UC) are measured respectively. Results show that the UC obtains better wettability after its modification and higher anti-polarization ability than the PC. A novel phenomenon has been found that the electrical potential of the modified UC anode is nearly 100 m V lower than that of the PC, reaching-570 ±10 m V(vs. SCE), and that it also has a much higher electron transfer kinetic activity, reaching 9399.4 m W m-2, which is 566.2-fold higher than that from plain graphite anode(PG). The fuel cell containing the UC anode has the maximum power density(256.0 m W m-2) among the three different BMFCs. Urea would enhance the bacteria biofilm formation with a more diverse microbial community and maintain more electrons, leading to a lower anodic redox potential and higher power output. The paper primarily analyzes why the electrical potential of the modified anode becomes much lower than that of others after urea modification. These results can be utilized to construct a novel BMFC with higher output power and to design the conditioner of voltage booster with a higher conversion ratio. Finally, the carbon foam with a bigger pore size would be a potential anodic material in conventional MFC.
基金supported by the National Natural Science Foundation of China(No.22075262).
文摘Marine sediment microbial fuel cell(MSMFCs)can be utilized as a long lasting power source to drive small instruments to work for long time on ocean floor and its higher power has a significant meaning for practical application.Anode modification can greatly improve the performance of MSMFCs.Herein,humic acid(HA)and humic acid-iron ion complex(HA-Fe)were used to modify the anode for constructing a better MSMFCs.The results indicated that HA-Fe modified anode,better than HA modification,significantly improved the MSMFCs cell power output.The maximum power density of HA-Fe modified MSMFCs is 165.3 mW m−2,which are 6.5-folds of blank MSMFCs.The number of microorganisms on anode,redox activity,and relative kinetic activity were 1.8-,6.1-,and 13.1-folds of blank MSMFCs,respectively.The MSMFCs improvement would be attributed to the electron transfer media of HA and the valence conversion of Fe ions.A synergistic interaction between the naturally occurring HA and Fe ions on the anodic surface in marine sediments would make the modified anodes have‘renewable’characteristics,which is beneficial for the MSMFCs to maintain its long-term higher power.
基金supported by the Key Project of Natural Science Fund of Shandong Province (ZR2011BZ008)the Marine Renewable Energy Special Fund Project from the State Oceanic Administration PRC (GHME2011GD04)+2 种基金the Scientific and Technology Development Plan Project of Shandong Province,China (2008GG10007003)the Key Laboratory of Submarine Geoscience and Exploring Technology of the Ministry of Education,Ocean University of China (Grant No. 2008-01)the Key Laboratory of Marine Environment & Ecology,Ministry of Education (Grant No. 2008010)
文摘Microbial fuel cell(MFC) on the ocean floor is a kind of novel energy-harvesting device that can be developed to drive small instruments to work continuously.The shape of electrode has a great effect on the performance of the MFC.In this paper,several shapes of electrode and cell structure were designed,and their performance in MFC were compared in pairs:Mesh(cell-1) vs.flat plate(cell-2),branch(cell-3) vs.cylinder(cell-4),and forest(cell-5) vs.disk(cell-6) FC.Our results showed that the maximum power densities were 16.50,14.20,19.30,15.00,14.64,and 9.95 mWm-2 for cell-1,2,3,4,5 and 6 respectively.And the corre-sponding diffusion-limited currents were 7.16,2.80,18.86,10.50,18.00,and 6.900 mA.The mesh and branch anodes showed higher power densities and much higher diffusion-limited currents than the flat plate and the cylinder anodes respectively due to the low diffusion hindrance with the former anodes.The forest cathode improved by 47% of the power density and by 161% of diffusion-limited current than the disk cathode due to the former's extended solid/liquid/gas three-phase boundary.These results indicated that the shape of electrode is a major parameter that determining the diffusion-limited current of an MFC,and the differences in the elec-trode shape lead to the differences in cell performance.These results would be useful for MFC structure design in practical applica-tions.
基金supported by the National Defense Science and Technology Innovation Zone Project (Nos. 17H863-05-ZT-002-040-001 and 18-H863-05-ZT-002-01301
文摘Improving the performance of anode is a crucial step for increasing output power of marine sediment microbial fuel cells(MSMFCs)to drive marine monitor to work for a long term on the ocean floor.A pyrolyzed iron phthalocyanine modified multi-walled carbon nanotubes composite(FePc/MWCNTs)has been utilized as a novel nodified anode in the MSMFC.Its structure of the composite modified anode and electrochemical performance have been investigated respectively in the paper.There is a substantial improvement in electron-transfer efficiency from the bacteria biofilm to the modified anode via the pyrolyzed FePc/MWCNTs composite based on their cyclic voltammetry(CV)and Tafel curves.The electron transfer kinetic activity of the FePc/MWCNTs-modified anode is 1.86 times higher than of the unmodified anode.The maximum power density of the modified MSMFC was 572.3±14 m W m^-2,which is 2.6 times larger than the unmodified one(218.3±11 m W m^-2).The anodic structure and cell scale would be greatly minimized to obtain the same output power by the modified MSMFC,so that it will make the MSMFC to be easily deployed on the remote ocean floor.Therefore,it would have a great significance for us to design a novel and renewable long term power source.Finally,a novel molecular synergetic mechanism is proposed to elucidate its excellent electrochemical performance.
基金supported by the National Natural Science Foundation of China(No.22075262)。
文摘The electrochemical performances of cathode play a key role in the marine sediment microbial fuel cells(MSMFCs)as a long lasting power source to drive instruments,especially when the dissolved oxygen concentration is very low in seawater.A CTS-Fe^(3+)modified cathode is prepared here by grafting chitosan(CTS)on a carbon fiber surface and then chelating Fe^(3+)through the coordination process.The electrochemical performance in seawater and the output power of the assembled MSMFCs are both studied.The results show that the exchange current densities of CTS and the CTS-Fe^(3+)group are 5.5 and 6.2 times higher than that of the blank group,respectively.The potential of the CTS-Fe^(3+)modified cathode increases by 138 mV.The output power of the fuel cell(613.0 mW m^(-2))assembled with CTS-Fe^(3+)is 54 times larger than that of the blank group(11.4 mW m^(-2))and the current output corresponding with the maximum power output also increases by 56 times.Due to the valence conversion between Fe^(3+)and Fe^(2+)on the modified cathode,the kinetic activity of the dissolved oxygen reduction is accelerated and the depolarization capability of the cathode is enhanced,resulting higher cell power.On the basis of this study,the new cathode materials will be encouraged to design with the complex of iron ion in natural seawater as the catalysis for oxygen reduction to improve the cell power in deep sea.
基金This work was supported by the National Natural Sci-ence Foundation of China(No.22075262).
文摘Anode modification plays a key role in higher power output in marine sediment microbial fuel cells(MSMFCs).A low-molecular organosilicon compound(3-aminopropyltriethoxysilane)was grafted onto the surface of carbon felt using chemical method and a composite modified anode was prepared through organic ligands coordination Fe^(3+)for better electro-chemical per-formance.Results show that the biofilm resistance of the composite modified anode(2707Ω)is 1.3 times greater than that of the unmodified anode(2100Ω),and its biofilm capacitance also increases by 2.2 times,indicating that the composite modification pro-motes the growth and attachment of electroactive bacteria on the anode.Its specific capacitance(887.8 Fm^(−2))is 3.7 times higher than that of unmodified anode,generating a maximum current density of 1.5Am^(−2).In their Tafel curves,the composite modified anodic exchange current density(5.25×10^(−6)Acm^(−2))is 5.8 times bigger than that of unmodified anode,which suggests that the electro-chemical activity of redox,anti-polarization ability and electron transfer kinetic activity are significantly enhanced.The marine sediment microbial fuel cell with the composite modified anode generates the higher power densities than the blank(203.8mWm^(−2) versus 45.07mWm^(−2)),and its current also increases by 4.4 times.The free amino groups on the anode surface expands a creative idea that the modified anode ligates the natural Fe(Ⅲ)ion in sea water in the MSMFCs for its higher power output.
文摘基于实际工程,借助电磁暂态仿真软件EMTP-RV,建立了广西灵川县灵田风电场的详细仿真模型及与风电场接入同一变电站110 k V母线的灵川电铁牵引站及机车负荷模型。研究了风电场在不同风速出力和电铁负荷状态下公共接入点电能质量,以及风电场与电铁牵引负荷接入同一110 k V母线的相互影响。并开发了电能质量计算模板用于多种电能质量指标的计算。多种运行工况的仿真表明,风电场与电铁负荷接入同一母线会恶化电网的运行条件,导致公共接入点剧烈电压波动,并向公共电网注入大量谐波。针对仿真中揭示的电压波动与功率振荡现象,结合现场条件,针对性提出合理调度风电出力、谐波治理与无功补偿等多项改善措施,使接入点的电能质量满足国家标准。
