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Watt-level road-vibration energy acquisition technology has wide application prospects because it can supply power to wireless low-power traffic-infrastructure sensors and solve power supply, wiring, and transmission difficulties. However, the depolarization and fragmentation of piezoelectric ceramics under long-term traffic loads leads to a significant decrease in their energy conversion efficiency. Hence, in this study, the PZT-5H piezoelectric ceramics used in road piezoelectric energy harvesters were recycled. An entire process was proposed for recycling piezoelectric ceramics. The experimental results show that the piezoelectric ceramics before and after recycling had a stable phase structure and excellent performance parameters. Under identical polarization conditions, the piezoelectric charge constant d33 of the recycled ceramics reached 75% of that of the initial ceramics. Subsequently, the output performance of the piezoelectric harvester unit was tested under different traffic loads. When the excitation displacement was 1 mm and the excitation frequency was 10 Hz, the maximum open-circuit voltage of the proposed piezoelectric harvester unit was 21.08 V, close to the 23.13 V of the initial ceramic harvester; furthermore, the power generation performance recovery reached 91.14%. In this study, a technological process for recycling piezoelectric ceramics in a piezoelectric road energy harvester was proposed to offer new ideas for the industrialization of piezoelectric road backends. [ABSTRACT FROM AUTHOR]

Copyright of Environmental Science & Technology (10036504) is the property of Editorial Board of Environmental Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the long-term electricity generation and driving sensor work process of marine sediment microbial fuel cells(MSMFCs), its cathode in the seawater may be embedded into the marine sediment, which will affect the electrochemical performance and lead to MSMFCs failure. The article simulated the embedding ratio of cathodes in sediment in the laboratory: 1/3, 1/2, 2/3, in order to investigate the changes of the electrochemical performance of the cathode and the electricity generation performance of MSMFCs. The results show that: the open circuit potential dropped and the required longer steady time with the higher embedding ratio of the cathode. Its capacitance decreased gradually, and the minimum capacitance was 32 F/cm2 (2/3 group), which was 0.72 times of the Blank. The kinetic activity decreased firstly and then increased, and its maximum activity was 1.61 times of the Blank (2/3 group); The maximum power density of the MSMFCs was 140.83 mW/m2 (1/3 group), which was 1.21 times of the Blank. With the increase of embedding ratio of the cathode in the marine sediment, its electrochemical performance and electricity generation performance of MSMFCs both fluctuates, but the normal operation of MSMFCs can still be ensured.

In microbial fuel cell (MFC), the anode is the carrier of microbial attachment and growth, and its material and surface structure play a vital role in MFC electricity generation. Therefore, anode surface optimization is an effective way to improve MFC performance. Although the power generation of bacteria has been confirmed and studied as early as the beginning of the 20th century, up to now, MFC still has the extremely challenging problem of low current and low power output in practical application. To improve the performance of MFC, several strategies have been applied to enhance the bacterial extracellular electron transfer. One promising technology is the genetic engineering approach, and some outstanding research results have been obtained. Another effective strategy is to design and fabricate a high-performance electrode because anode material is the essential factor affecting MFC performance, which provides surface active sites for microbial adhesion, reproduction and interfacial electron transfer. At present, the MFC anodes mainly include carbon-based electrodes and a variety of metal electrodes, but untreated anodes have always been unable to overcome the obstacle of low power output. Anode modification, a common and effective method, is employed for improving the power output of MFC. For this reason, this review is primarily focused on the applications of various anode materials and its nanoscale modification in the field of MFC, including the influence of different anode materials on the power output of MFC, and analyzes the reasons why anode modification enhances output performance. Furthermore, the influence of anode research on the practical application of MFC in the future is prospected. [ABSTRACT FROM AUTHOR]

To explore the operating performance of the organic Rankine cycle (ORC) experimental system with low cooling-water temperature in cold region, an organic Rankine cycle experimental system was built in Harbin, and the thermal model was also given. The operating performance of condensation temperature, net power output, power generation and power-electricity conversion efficiency of the system was investigated with heat-source temperatures of 79.0-113.6 ℃ and cooling-water temperature of 6.4 ℃. The results show that the condensation temperature of ORC system with cooling-water temperature of 6.4 ℃ in Harbin is 13.1 ℃, which is 19.0 ℃ lower than that with cooling-water temperature of 30.8 ℃ in Taipei. The maximum electricity generation of the system in Harbin is 1.44 kW, which is 30.9% (0.34 kW) higher than that in Taipei. The low temperature cooling water in Harbin can reduce the operating condensation temperature of ORC system for improving the power and electricity generation performance of the system. [ABSTRACT FROM AUTHOR]

We examine the role of regulatory independence on electricity generation performance in India. Electricity generation in India is exposed to several regulatory jurisdictions with varying levels of regulatory independence. Based on the level of regulatory independence, we classify Indian coal fired power plants into two groups, and evaluate their performance over the period 2005–14 using the non-radial directional distance function model in a meta-frontier framework. We find that plants under relatively less independent state regulators are more inefficient than plants under the largely independent central regulator. Differences in independence between state and central regulators account for nearly half of the inefficiency of plants under the state regulation. Regression analysis reveals that the channels of causation of regulatory independence on plant performance are through its effects on coal consumption and electricity generation. Our results suggest the need for two policy interventions: (1) providing greater independence to state regulators for bridging the performance gaps between plants subject to different regulators, and (2) a more forward-looking norm setting process through the use of benchmarking techniques by identifying best practices and performance among plants. [ABSTRACT FROM AUTHOR]

In microbial fuel cell (MFC), the anode is the carrier of microbial attachment and growth, and its material and surface structure play a vital role in MFC electricity generation. Therefore, anode surface optimization is an effective way to improve MFC performance. Although the power generation of bacteria has been confirmed and studied as early as the beginning of the 20th century, up to now, MFC still has the extremely challenging problem of low current and low power output in practical application. To improve the performance of MFC, several strategies have been applied to enhance the bacterial extracellular electron transfer. One promising technology is the genetic engineering approach, and some outstanding research results have been obtained. Another effective strategy is to design and fabricate a high-performance electrode because anode material is the essential factor affecting MFC performance, which provides surface active sites for microbial adhesion, reproduction and interfacial electron transfer. At present, the MFC anodes mainly include carbon-based electrodes and a variety of metal electrodes, but untreated anodes have always been unable to overcome the obstacle of low power output. Anode modification, a common and effective method, is employed for improving the power output of MFC. For this reason, this review is primarily focused on the applications of various anode materials and its nanoscale modification in the field of MFC, including the influence of different anode materials on the power output of MFC, and analyzes the reasons why anode modification enhances output performance. Furthermore, the influence of anode research on the practical application of MFC in the future is prospected. [ABSTRACT FROM AUTHOR]

Copyright of Journal Of Sichuan University (Natural Sciences Division) / Sichuan Daxue Xuebao-Ziran Kexueban is the property of Editorial Department of Journal of Sichuan University Natural Science Edition and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract Background Extracellular electron transfer (EET) is essential in improving the power generation performance of electrochemically active bacteria (EAB) in microbial fuel cells (MFCs). Currently, the EET mechanisms of dissimilatory metal-reducing (DMR) model bacteria Shewanella oneidensis and Geobacter sulfurreducens have been thoroughly studied. Klebsiella has also been proved to be an EAB capable of EET, but the EET mechanism has not been perfected. This study investigated the effects of biofilm transfer and electron mediators transfer on Klebsiella quasipneumoniae sp. 203 electricity generation performance in MFCs. Results Herein, we covered the anode of MFC with a layer of microfiltration membrane to block the effect of the biofilm mechanism, and then explore the EET of the electron mediator mechanism of K. quasipneumoniae sp. 203 and electricity generation performance. In the absence of short-range electron transfer, we found that K. quasipneumoniae sp. 203 can still produce a certain power generation performance, and coated-MFC reached 40.26 mW/m2 at a current density of 770.9 mA/m2, whereas the uncoated-MFC reached 90.69 mW/m2 at a current density of 1224.49 mA/m2. The difference in the electricity generation performance between coated-MFC and uncoated-MFC was probably due to the microfiltration membrane covered in anode, which inhibited the growth of EAB on the anode. Therefore, we speculated that K. quasipneumoniae sp. 203 can also perform EET through the biofilm mechanism. The protein content, the integrity of biofilm and the biofilm activity all proved that the difference in the electricity generation performance between coated-MFC and uncoated-MFC was due to the extremely little biomass of the anode biofilm. To further verify the effect of electron mediators on electricity generation performance of MFCs, 10 µM 2,6-DTBBQ, 2,6-DTBHQ and DHNA were added to coated-MFC and uncoated-MFC. Combining the time–voltage curve and CV curve, we found that 2,6-DTBBQ and 2,6-DTBHQ had high electrocatalytic activity toward the redox reaction of K. quasipneumoniae sp. 203-inoculated MFCs. It was also speculated that K. quasipneumoniae sp. 203 produced 2,6-DTBHQ and 2,6-DTBBQ. Conclusions To the best of our knowledge, the three modes of EET did not exist separately. K. quasipneumoniae sp.203 will adopt the corresponding electron transfer mode or multiple ways to realize EET according to the living environment to improve electricity generation performance.

Three identical H-type microbial fuel cell reactors were used to study the removal of organic pollutant and electricity generation performance by microbial fuel cells (MFC) under different sludge concentrations. The results showed that when the average sludge concentration (MLSS) of anode chamber is 2530 mg • L-1,5183 mg • L-1 and 10 200 mg • L-1, MFC can remove organics well. The increase of sludge concentration is beneficial to the formation of anode biofilm and the start-up of the system. However,it is not that the higher the sludge concentration,the greater the MFC's ability to remove organic pollutant and generate electricity. With the increase of sludge concentration,the removal of organic matter increases first and then decreases,while the internal resistance of the system decreases first and then increases,leading to the decrease of output voltage and power density. At the anode sludge concentration for an average of 5183 mg • L-1,effect of MFC on removal of organic pollutant,the highest reached 85%,the output voltage of 0. 78 V,the apparent resistance is low, 344.4 f2,power density of 421. 9 mW • m-3,charge and discharge performance is better. It indicates that, the suitable activated sludge concentration is favorable for the removal of organics and electricity generation of MFC. The results provide a theoretical basis and operational method for improving MFC processing efficiency and electricity performance. [ABSTRACT FROM AUTHOR]

The variation of substrate concentration in anode chamber directly affects the power generation efficiency and decontamination performance of microbial fuel cell (MFC). In this study, three concentrations of swine wastewater with 800 mg/L, 1600 mg/L and 2500 mg/L were selected as substrates, and the performance of MFC and response characteristics of anode microbial community were investigated. The results show that the concentration of a selected substrate is positively correlated with the output voltage of MFC and chemical oxygen demand (COD) removal rate. The microbial community diversity in the anode chamber and the performance of battery can be significantly affected when concentration changes in different ways, which helps to selectively cultivate the adaptable dominant bacteria to enhance the stability and decontamination performance of MFC. The community structure of anodic biofilm is mainly composed of Proteobacteria, Bacteroidetes, Firmicutes, Chloroflexi and Spirochaetae. These findings are meaningful to improve the treatment effects of swine wastewater and can help to find out the mechanism of varying concentration that influences the production of microorganisms in MFC.

To study the feasibility to utilize the microbial desalination cell (MDC) to desalinate complex saltwater, the objective of this study was to investigate the effects of different salinity anions on anode performance. Experiments were conducted using three different salinity anions (Cl − , SO 4 2 − , and HCO 3 − ) with different concentrations in the anode of two-chamber microbial fuel cell (MFC). Results showed that the supplement of anions, with concentration ranges of 25–50 mM for Cl − , 25 mM for SO 4 2 − , and 25–100 mM for HCO 3 − , into the substrate increased the voltage output of the MFC. With the HCO 3 − concentrations from 0 to 100 mM, the coulombic efficiencies increased from 29% to 44%, and the power densities increased from 465 to 1064 mW/m 2 . At the same conductivity, the electron production in the MFC with the anions was in the order: HCO 3 − > Cl − > SO 4 2 − . The presence of HCO 3 − enhanced the buffer capacity of the anolyte and maintained the activity of the anode biofilm, in which the dominant species included Geobacter uraniireducens , Desulfofaba fastidiosa , and Mycobacterium fortuitum . This study suggests that the MDC can be used to desalinate complex saltwater to improve wastewater treatment in the anode chamber. [ABSTRACT FROM AUTHOR]

Because geologic sedimentation and hydrofracturing processes are not homogeneous, the reservoirs of enhanced geothermal systems (EGSs) are also heterogeneous; this has a significant influence on the electricity generation performance of EGS. Presently, there are a lack of systematic and profound studies on the effect of vertical permeability heterogeneity in stratified formation on the electricity generation performance of EGS. In order to uncover the effect of vertical permeability heterogeneity on electricity generation performance of EGS, in this work we analyzed the influence of vertical permeability heterogeneity on electricity generation performance of EGS through a numerical method based on geological data at the Yangbajing geothermal field. The results indicate that when the average permeability of stratified formations is constant for a homogeneous reservoir, the system attains maximum water production rate, maximum electric power, minimum reservoir impedance and maximum pump power; with the increasing of the vertical permeability heterogeneity, the water production rate gradually decreases, the electric power gradually declines, the reservoir impedance gradually increases and the pump power gradually declines. When the average permeability of stratified formations is constant, with the increasing of the vertical permeability heterogeneity, the injection pressure and energy efficiency only changes very slightly; this indicates that the vertical permeability heterogeneity is not the main factor affecting the system injection pressure and energy efficiency. [ABSTRACT FROM AUTHOR]

The variation of substrate concentration in anode chamber directly affects the power generation efficiency and decontamination performance of microbial fuel cell (MFC). In this study, three concentrations of swine wastewater with 800 mg/L, 1600 mg/L and 2500 mg/L were selected as substrates, and the performance of MFC and response characteristics of anode microbial community were investigated. The results show that the concentration of a selected substrate is positively correlated with the output voltage of MFC and chemical oxygen demand (COD) removal rate. The microbial community diversity in the anode chamber and the performance of battery can be significantly affected when concentration changes in different ways, which helps to selectively cultivate the adaptable dominant bacteria to enhance the stability and decontamination performance of MFC. The community structure of anodic biofilm is mainly composed of Proteobacteria, Bacteroidetes, Firmicutes, Chloroflexi and Spirochaetae. These findings are meaningful to improve the treatment effects of swine wastewater and can help to find out the mechanism of varying concentration that influences the production of microorganisms in MFC. [ABSTRACT FROM AUTHOR]