Discover insights from thousands of peer-reviewed papers on microbial electrochemical systems
Romeo Gabriel Dumitrache
· 2021
A moving bed biofilm reactor was studied for its capability of carbon oxidation and nitrification. The hybrid system made use of suspended biomass in the forms of microbial aggregates and attached biomass in the form of biofilms on suspended carriers. The carriers used for biofilm support were made of polyethylene and have a wagon wheel shape. The carrier fill ratio, which is defined as the volume ratio of carrier to the whole reactor was a key characteristic parameter of the reactor. The experimental runs used different carrier filling ratios from 25 to 50% to determine the optimal operating value for this type of hybrid reactor. Also the nutrient conditions were modified to test the capacity of the system to adapt to various changes in phosphorus loading in the influent wastewater. The results showed that for an influent chemical oxygen demand (COD) of 600 mg/L, ammonia of about 24 mg/L and hydraulic reaction time of 6 hours there was no difference in the performance of the system under the different carrier filling rations.
Rubini S
JOURNAL OF ADVANCED APPLIED SCIENTIFIC RESEARCH · 2017
Environmental issues associated with water sanitation are not confined to developing countries alone but are the most basic human and environmental necessities all over the world. Wastewater sources are major causes for environmental pollution in surface and ground water bodies. Current wastewater treatment technologies are not sustainable to meet the ever growing water sanitation needs due to rapid industrialization and population growth, simply because they are energy and cost intensive leaving latitude for development of technologies that are energy conservative or energy yielding. For the present and future context, microbial fuel cells technology may present a sustainable and an environmentally friendly route to meet the water sanitation needs. Microbial fuel cell based wastewater systems employ bio-electrochemical catalytic activity of microbes to produce electricity from the oxidation of organic, and in some cases inorganic, substrates present in urban sewage, agricultural, dairy, food and industrial wastewaters. It provides an overview of current energy needs for wastewater treatment and potential energy recovery options followed by a comprehensive review of the principles of wastewater treatment, substrate utilization (organic removal), recent process developments, nutrient and metal removal capacities in microbial fuel cells. Several issues related to process performance, organic removal capacities and potential environmental impacts were discussed in detail
Geeta Kumari, Aman Jaiswal, Devashish Pathak et al.
Agriculture Association of Textile Chemical and Critical Reviews · 2025
Naturally occurring bacteria in wastewater have a significant potential for bioremediation, making them valuable for biological wastewater treatment. The effectiveness of microbial communities in breaking down pollutants depends on their diversity and metabolic capabilities. Therefore, developing environmentally friendly, indigenous microbial consortia is crucial for efficient wastewater treatment. In this study, 20 bacterial strains were isolated from wastewater samples collected from the dairy industry, sugar industry, and hostel sewage water in Pusa, Bihar. These isolates were screened for their ability to degrade starch, protein, and fat, as well as their potential to reduce Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD). Among the 20 isolates, 18 exhibited starch degradation, 10 showed protein degradation, and 11 demonstrated fat degradation. Notably, seven isolates (DS-13, DS-27, DS-57, DS-58, DS-67, DS-68, and DS-72) exhibited all three degradation activities and were further analyzed for their impact on BOD and COD reduction. Out of these seven isolates, three (DS-58, DS-67, and DS-72) demonstrated the highest reductions in BOD and COD when inoculated into autoclaved effluents from the dairy industry, sugar industry, and hostel sewage. In contrast, the blank (un-autoclaved effluents without bacterial inoculation) recorded BOD levels of 835 mg/L, 1035 mg/L, and 620 mg/L, and COD levels of 1680 mg/L, 2280 mg/L, and 1470 mg/L for the respective effluent sources. To enhance biodegradation efficiency, these three bacterial isolates were combined into different formulations, creating four distinct microbial consortia. Among them, consortium C4 (comprising DS- 58, DS-67, and DS-72) exhibited the highest biodegradation efficiency, with starch degradation of 14 mm, protein degradation of 24 mm, and fat degradation of 18 mm. Additionally, C4 significantly reduced BOD levels from 115 mg/L to 353 mg/L and COD levels from 407 mg/L to 641 mg/L. These findings indicated that the formulated C4 consortium has strong potential for biological wastewater treatment by effectively breaking down organic pollutants and reducing water pollution. Its application in wastewater management can contribute to environmentally sustainable bioremediation strategies.
Suraj Sevda, Ibrahim M Abu Reesh, Zhen He
Qatar Foundation Annual Research Conference Proceedings Volume 2016 Issue 1 · 2016
The availability of drinking water from the current available sources is decreasing due to the high demand and population increase. Seawater is a potential source for drinking water but the current desalination technology is energy intensive, therefore energy efficient desalination technology is desired. In the past decade microbial fuel cells (MFC) were emerged for simultaneous wastewater treatment and bioelectricity generation, in the anodic chamber of MFCs, microbes work as a biocatalyst to generate electrons from the oxidation of the organic compounds (wastewater) and transfer them to the anode electrode. These electrons flow through an external circuit to the cathode electrode where they used to reduce terminal electron acceptors (e.g., oxygen). Microbial desalination cells (MDC) are new potential technique for seawater desalination, in this device energy from wastewater is extracted by using microbes and without any external energy source, water desalination is driven. To convert an MFC to an MDC, a middle chamber is inserted in between the anodic and cathodic chambers of MFC using a pair of anion and cation exchange membranes. This middle chamber works as a desalination chamber in the MDC (Fig. 1). The cations and anions from the desalination chamber moved to the anodic and the cathodic chambers, respectively, due to the cell potential difference between the anode electrode and the cathode electrode; as a result, salts are removed from the saltwater. The first MDC study was reported in 2009 and since then there have been nearly 74 papers published about various aspects of MDC design and development, indicating a strong interest and rapid development of this technology. During this short period of time, various MDC designs were developed for salt removal and wastewater treatment. The desalination chamber volumes were increased from 3 ml to 105 liters and further progress is going on for salt removal and at the same time wastewater treatment. The performance of MDC was investigated using various concentrations of saline water in desalination chamber using industrial or synthetic wastewater in the anodic chamber. Different MDC designs were reviewed here. These developed new MDC designs named as air cathode MDC, stacked MDC (SMDC), up flow MDC (UMDC), recirculated MDC (RMDC), microbial electrodialysis cell (MEDC), submerged microbial desalination- denitrification cell (SMDDC), microbial capacitive desalination cell (MCDC) and osmotic microbial desalination cell (OsMDC). Different anion and cation exchange membranes were compared for power generation and desalination efficiency. This paper also reviews different substrates that have been used in MDCs so far. The MDCs provide an energy self-sustainable system in that water desalination and wastewater treatment conducted by using microbes as catalyst in the anodic chamber. Still the available MDCs were very small in volume that can't meet today's water desalination needs. In the long term operation of MDC, the membrane fouling and electrode stability are still two major problems limiting the development of MDCs. The possibility of scale-up, possible future potentials for synchrony of the MDCs with current desalination techniques were also discussed. Case study with real wastewater in the anodic chamber and real seawater in the desalination chamber were also discussed. Acknowledgements This work was made possible by NPRP grant # 6-289-2-125 from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the authors. Reference Sevda, S., Yuan, H., He, Z., Abu-Reesh, I.M., 2015. Microbial desalination cells as a versatile technology: Functions, optimization and prospective. Desalination 371, 9–17. doi:10.1016/j.desal.2015.05.021
Rachna Jain, Saravana Devi, Dipanjali Majumdar
Research Square · 2022
Abstract Wastewater management is a powerful tool for restricting containment and recycling of wastewater upto surface/drinking standard as per end use. The present study is designed to explore the treatment potential of indigenous microflora for effective and efficient recycling of sanitary landfill leachate under in-situ conditions. Three indigenous strains were screened and characterized as MT186162, MT186163, and MT186164. Their i n-situ metabolic potential was observed by augmentation into leachate under optimized culture conditions and depicted in the form of percent reduction in major pollutant parameters viz. BOD, COD, Chlorides, phenols, TDS, and TKN at regular time intervals. In our knowledge, it is the very first study on in-situ leachate treatment by indigenous microflora. Results revealed that bacterial growth correlated well with their metabolic potential ( p>0.01 ). >83% of BOD, COD, phenolics, and TKN were reduced with water quality reaching surface discharge standards after 41 days of augmentation. Microbial metabolic potential varied significantly ( p>0.05 ) in the order of MT186163> MT186162> MT186164 and followed first order kinetics with rate constants k deg - 0.0062-1.131 day -1 and t 1/2 of 0.612-111.7 days. In concurrence, the Leachate Pollution Index of the landfill site also dropped significantly from 13.39 to 5.1-5.2. AMES test exhibits no mutagenicity in the treated leachate samples. The study concludes that isolated strains are pervasive towards leachate contamination and efficiently reduced it upto surface wastewater discharge standards. Hence their potential can be utilized further while designing commercial leachate treatment strategies for wastewater recycling.
Mercedes Villar Navarro, Miguel Angel Cabezón, Patricia C. Damiani
Journal of Chemistry · 2018
In the present work, a chemometric-assisted spectrofluorimetric method has been developed for the simultaneous determination of natural fluorescent pesticides, carbaryl, carbendazim, and thiabendazole, in orange and banana. Only a simple extraction with methanol was required as sample pretreatment. Emission-excitation fluorescence matrices were obtained and resolved by using a second-order multivariate calibration method based on unfolded partial least-squares combined with residual bilinearization (U-PLS/RBL) for achieving “second-order advantage.” In this way, pesticides were determined in fruits even in the presence of inner filter effects, background interactions, strong spectral overlapping, and unexpected components. U-PLS can cope with effects that cause trilinearity loss such as, inner filter effects, including background in the calibration set; meanwhile, RBL allows to resolve the presence of unexpected components. The extraction technique was validated against a commonly applied technique based on the use of ethyl acetate and sodium sulfate. Besides, results obtained for real samples were statistically compared with those obtained by using HPLC. LODs of 0.038, 0.054, and 0.018 mg·kg −1 and 0.044, 0.072, and 0.020 mg·kg −1 were obtained for carbaryl, carbendazim, and thiabendazole in banana and orange samples, respectively; values were in accordance with the MRLs (Maximum Residue Limits) established by different official control organizations such as National Food Safety and Quality Service (SENASA), Codex Alimentarius (based on Food and Agriculture Organization (FAO) of the United Nations and World Health Organization (WHO), and Environmental Protection Agency (EPA).
Hyeonaug Hong, Jang Mee Lee, JaeHyoung Yun et al.
ECS Meeting Abstracts · 2020
Thylakoids are the photosynthetic complexes that absorb light energy to produce photosynthetic electrons (PEs) in the chloroplast of plant cells. PE production starts from water splitting at photosystem II (PSII) in the thylakoid membrane and they are excited by absorbing photon energy. Over the last decade, many researchers have attempted to extract PEs from thylakoid by enhancing attachment of thylakoid membranes to an electrode or using artificial mediators. However, these have some limitations including increased ohmic resistance from the length of tethering molecules and energy loss due to artificial mediators. In this study, we propose a photosynthetic electrochemical cell based on RuO 2 nanosheet modified electrode for the photosynthetic energy harvesting from thylakoids. RuO 2 is known as one of the most conductive metal oxides. Metal oxides have partially positive charges that can improve attachment of negatively charged thylakoids to the electrode. Also, partially positively and negatively charged characteristics of RuO 2 surfaces induce ensemble docking between electron carriers and electrode surface, which can attract both negatively charged electron carriers and positively charged electron carriers. Furthermore, RuO 2 nanosheets show a unique characteristic of proton adsorption, which can sustain positive electrical potential during PEs extraction. For photosynthetic energy harvesting, the photosynthetic electrochemical cell was constructed with anode based on thylakoid and air-cathode based on Pt-C, which separated by a proton exchange membrane. The light was controlled by a 100 W halogen lamp to operate the photosystem so that excited PEs can be extracted to the electrode. The surface potential of RuO 2 nanosheets modified electrodes was 250 mV vs. Ag/AgCl, which shifted positively more than 100 mV than that of the bare Au electrode. From the inspection of RuO 2 lattice by x-ray absorption spectroscopy, positively shifted surface potential is the result of proton adsorption. A positively biased electrode surface can induce a large amount of PEs extraction from the electron carriers than the Au electrode. When the light is illuminated on the thylakoids deposited electrodes, 8.9 ± 6.3 mV and 88.7 ± 13.8 mV of the surface potentials were measured from the Au and the RuO 2 modified electrode, respectively. These lowered electrode potentials are due to the redox potential of the electron carriers on the electron transport chain of the thylakoid membrane. The open-circuit voltages (OCV, the subtracted potential between the cathode and the anode) were measured 575.1 ± 6.4 mV and 424.0 ± 17.2 mV from the Au and the RuO 2 electrode, respectively. Although OCV of the RuO 2 electrode is lower than the Au electrode, the power density of the RuO 2 electrode shows 4 times higher than the Au electrode, and this is due to the enhanced PEs extraction by both the surface charge and the proton adsorption characteristics of RuO 2 nanosheets.
H. Madi, S. Diethelm, S. Poitel et al.
Fuel Cells · 2015
Abstract This work presents the poisoning effect of organic oxo‐silicon compounds (siloxanes) which are generally found in sewage biogas. Lifetime and durability associated with solid oxide fuel cell (SOFC) technology is strongly related to the amount of contaminants that reach the stack. Several experiments on Ni anode‐supported (AS) single cells are performed in order to clarify the mechanism of degradation and also the possibility of cell performance recovery. Three experiments focus on the degradation and recovery of AS Ni‐YSZ fed with H 2 , co‐feeding 5 ppm D4‐siloxane (octamethylcyclotetrasiloxane, C 8 H 24 O 4 Si 4 ) as representative compound for the organic silicon species, at 800 °C. A fourth experiment focuses on the durability of the AS Ni‐YSZ cell with variable concentrations of the impurity (0–5 ppm), during steady state polarization (0.25 A cm −2 ) for 250 h, using simulated biogas‐reformate fuel H 2 /CO/CO 2 /H 2 O: irreversible degradation was observed with the D4‐impurity feed in the anode gas. Post‐test scanning electron microscopy (SEM) results indicate formation of SiO 2 (s) deposits, which block pores and reduce the TPB length.
Kottisa Patnaik, Yueying Peng, Rajashekar Badam et al.
ECS Meeting Abstracts · 2021
Currently graphite is the most commercially used anode material for lithium-ion batteries (LIB), however its limited theoretical capacity of 372 mAhg -1 and slow kinetics cannot satisfy the requirements for EVs. Hence, alternative high energy density anode materials with fast kinetics are the need of the hour. The most recent development involves Mitsubishi Outlander PHEV which takes around 40 minutes for empty to full charging. Extreme fast charging, with a goal of 15 minutes fast charging, is poised to accelerate mass market production of electric vehicles. Extensive research is now directed towards carbonaceous materials that can fulfill the requirements for EV application. Key strategies involved in improving the rate capability of carbonaceous materials are (a) heteroatom doping, especially nitrogen doping and (b) increasing the d-spacing for accessing more active sites. Using conventional methods of heteroatom doping like pyrolysis of graphene oxide with urea or melamine as nitrogen source led to inclusion of up to 12 at% of nitrogen in general. Inclusion of nitrogen showed improvement in rate capability and capacity. Further search to increase nitrogen content led to the application of graphitic carbon nitride with nearly 55 at% nitrogen. Nevertheless, due to less electronic conductivity and change of crystallinity upon lithiation curbed its application in lithium-ion battery. So, currently our objective is to use nitrogen rich polymer as a single source of nitrogen and carbon to prepare heavily nitrogen doped carbon with nearly 20 at% of nitrogen with increased d-spacing and understand its effect on Li ion storage. Poly (2, 5-benzimidazole) (PBI) was synthesized by homo-polycondensation method using a bio derivable starting material 3, 4-diaminobenzoic, as earlier reported by Kaneko et.al 1 . The as prepared PBI was ground into fine powder before pyrolyzing at 800 ℃ in nitrogen atmosphere. Obtained carbon material was washed with HCl and water repeatedly and dried at 80 ℃ under vacuum before grinding into fine powder using mortar and pestle. Obtained material was systematically characterized before preparation of anodes for Li ion battery application. The SEM-EDX data revealed the content of nitrogen was as high as 18 at%. Using XPS studies, different types of nitrogen moieties were identified. Deconvolution of N1s peak revealed the presence of nitrogen in four different forms, graphitic nitrogen (10.3%), pyridinic nitrogen (6%), pyrrolic nitrogen (0.6%) and oxidized nitrogen (0.6%). The presence of pyridinic and graphitic nitrogen improve the electrical conductivity. The presence of high pyridinic nitrogen results in improved electrochemical activity. The contribution of pyridinic nitrogen in lithium storage is known to be maximum. XRD technique was utilized to understand the d-spacing of the material. Reflection corresponding to C (002) was used to calculate d-spacing. The results revealed that the d-spacing was found to be 3.5 Å which is nearly 0.2 Å higher than conventional graphite. The increased d-spacing can promote in faster diffusion of Li ion during intercalation and de-intercalation. TEM micrographs revealed the presence of macropores and mesopores. Using Cyclic Voltammograms at different scan rates and Randles Sevcik equation, the diffusion coefficient was calculated. Diffusion coefficient of PY PBI 800 was found to be several times higher than the conventional graphite anode, attributed to the increased d-spacing along with porous nature. Upon galvanostatic charge-discharge studies at different current rates, anode showed reversible capacity with nearly 99% coulombic efficiency upto 5C (1.8 Ag -1 ) rate. Further, long cycling studies were performed for >1000 cycles at 0.4, 0.8 and 1.8Ag -1 rates. Results indicated that PY PBI 800 can deliver highest de-lithiation capacity of ̴ 260 mAhg -1 at specific capacity of 0.4 Ag -1 rate (Fig) with nearly 88% capacity retention after 1000 cycles. At higher current rate of 0.8Ag -1 , and 1.8 Ag -1 it showed highest discharge capacity of 165 mAhg -1 and 135 mAhg -1 with 90% and 75% capacity retention after 1000 cycles respectively. At 5C current rate, the battery can be charged and discharged in just 9 mins. Further, full cell was studied with LiCoO 2 as cathode and PY PBI 800 as anode. Full cell studies also revealed the promising nature of PY PBI 800. Thus, carbonization is found to be a single method to enable high N-doping and increased d-spacing. The battery’s performance of charge discharge in just 9 min at 5C, with good capacity retention of nearly 75% after 1000 cycles demonstrated its promising potential for EV application. References: (1) Nag, A., Ali, M.A., Singh, A., Vedarajan, R., Matsumi, N., Kaneko, T., J. Mater. Chem. A, 2019,7, pp: 4459-4468 Acknowledgement We thank the financial support from Strategic Innovation Promotion Program (SIP), Technologies for Smart Bio-Industry and Agriculture, Japan. Figure 1
Zainab Karam, Chiara Busa
ECS Meeting Abstracts · 2023
Lithium Ion batteries (LIB) demand has shown an exciting increase lately, particularly looking for light-weight solution for portable devices [1], [2]. Recently, The development and implementation of electrode material production techniques pushed the LIB's current state performance to further improvement. Silicon (Si) anode-based electrodes are considered an attractvie alternative to conventional graphite electrodes due to their high specific capacity [3]. Theoretically, Si could alloy with Li up to Li 4.4 Si and result in a specific capacity of 4200 mAh/g, where the mechanical stress within the electrode material causes loss in the conductivity and breaking of the cell. To overcome this issue, different methodologies have been tested for further improvement of Si implementation with different nanostructures [4]. On the other hand, the production rate of LIB is very important to meet the high demand for different technologies. and, a commercial Si grade is highly recommended along with the conventional tape-casting production method. Furthermore, water-based binders, such as Polyacrylic Acid and Carboxy methyl Cellulose (cellulose-based binders) plays an important role in electrode preparation, where it is supporting the volume expansion of Si and preserveing electrode morphology [5]. Herein, we focus on producing a high-quality Si electrode with cellulose binder, enhanced by conductive carbon allotrope additives. In this study, different Si grades will be tested with different concentrations along with conductive and binder [6]. Electrochemical characterization of the Si anode half cell , such as cycling, cyclic voltammetry, and Impedance spectroscopy vs Li + metal shows extended and stabilized cycling performance, inferring a reduced anode pulverization. References [1] M. Wakihara, ‘Recent developments in lithium ion batteries’, Mater. Sci. Eng. R Rep. , vol. 33, no. 4, pp. 109–134, Jun. 2001, doi: 10.1016/S0927-796X(01)00030-4. [2] B. Scrosati, ‘Recent advances in lithium ion battery materials’, Electrochimica Acta , vol. 45, no. 15, pp. 2461–2466, May 2000, doi: 10.1016/S0013-4686(00)00333-9. [3] S. Chae, M. Ko, K. Kim, K. Ahn, and J. Cho, ‘Confronting Issues of the Practical Implementation of Si Anode in High-Energy Lithium-Ion Batteries’, Joule , vol. 1, no. 1, pp. 47–60, Sep. 2017, doi: 10.1016/j.joule.2017.07.006. [4] J. Cho, ‘Porous Si anode materials for lithium rechargeable batteries’, J. Mater. Chem. , vol. 20, no. 20, pp. 4009–4014, May 2010, doi: 10.1039/B923002E. [5] P. Parikh et al. , ‘Role of Polyacrylic Acid (PAA) Binder on the Solid Electrolyte Interphase in Silicon Anodes’, Chem. Mater. , vol. 31, no. 7, pp. 2535–2544, Apr. 2019, doi: 10.1021/acs.chemmater.8b05020. [6] A. Meyer, F. Ball, and W. Pfleging, ‘The Effect of Silicon Grade and Electrode Architecture on the Performance of Advanced Anodes for Next Generation Lithium-Ion Cells’, Nanomaterials , vol. 11, no. 12, Art. no. 12, Dec. 2021, doi: 10.3390/nano11123448.
Y. Bai, C. Wang, C. Jin et al.
Fuel Cells · 2011
Abstract Anode current collection points (ACCPs) were fabricated on the outside surface of a tubular anode‐supported solid oxide fuel cell (SOFC). The ACCPs were distributed axially along the SOFC tube with the distance between every adjacent two ACCPs the same. The effect of collecting current with different number of ACCPs on the performance of the SOFC was studied. It was found that with the same effective area, using more ACCPs to collect the current leads to better performance, while with a SOFC with a determined total surface area, there is an optimum number of ACCPs to be made and used considering the area occupied by the ACCPs themselves.
Pei Fu, Yuansheng Song, Jian Yang et al.
Journal of Heat Transfer · 2020
Abstract Gradient particle size anode has shown great potential in improving the electrical performance of anode-supported solid oxide fuel cells (SOFCs). In this study, a 3D comprehensive model is established to study the effect of various gradient particle size distribution on the cell electrical performance for the anode microstructure optimization. The effect of homogeneous particle size on the cell performance is studied first. The maximum current density of homogeneous anode SOFC is obtained for the comparison with the electrical performance of gradient anode SOFC. Then the effect of various gradient particle size distribution on the cell molar fraction, polarization losses, and electronic current density distribution is analyzed and discussed in detail. Results show that increasing the particle diameter gradient can effectively reduce the anodic concentration overpotential. Decreasing the particle diameter of anode functional layer 2 is beneficial for reducing the activation and ohmic overpotentials. On these bases, the comprehensive electrical performance of SOFCs with gradient particle size anode and homogeneous anode is compared to highlight the optimal gradient particle diameter distribution. In the studied cases of this work, the gradient particle diameter of 0.7 μm, 0.4 μm, and 0.1 μm at anode support layer (ASL), anode functional layer 1, and anode functional layer 2 (case 3) is the optimal particle size distribution.
Nak Gyu Go, Seung Taek Lee, Woo Young Yoon
ECS Meeting Abstracts · 2019
Over the last several decades, new battery technologies have been developed due to the need for consistently high energy density batteries. Lithium metal is the ideal cathode for next-generation lithium batteries, because it has a high specific capacity (3860 mAh g −1 ) and the lowest reduction potential (−3.040 V vs. standard hydrogen electrode, SHE). However, safety issues caused by Li dendritic growth during Li plating interfere with the use of lithium metal-based rechargeable batteries. Li dendrites can cause dead lithium to accumulate on the lithium metal surface, resulting in increased resistance at the interface or short-circuiting, which can lead to explosion. Several studies have been proposed to inhibit the growth of lithium dendrites, such as electrolyte additives, surface coating, separator modification, and lithium metal host. In this experiment, Li was isolated by physically mixing Li and graphite to form a composite electrode, thereby suppressing Li dendrite growth. Li metal powder is synthesized by the droplet emulsion technique and this shape is prohibited dendrite growth. These Li metal powder+graphite composite anode was experimented with constant current charge/discharge tests and constant voltage tests. And the structure, morphology, and electrochemical properties of the new type of battery’s electrode were investigated by the implementation of X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), and energy dispersive spectroscopy (EDS). The result was analyzed by electrochemical impedance spectroscopy (EIS).
Farshid Zabihian, Asad Davari, Gifty Osei-Prempeh
International Journal of Renewable Energy Resources · 2023
The objective of this paper is to present the results of experimentations on the state-of-the-art anode electrocatalysts and the membrane-electrode assemblies (MEAs) developed for direct carbon monoxide fuel cells (DCMFCs). The custom-made platinum-ruthenium (Pt-Ru) MEAs along with a commercial MEA were tested to evaluate the impacts of cell temperature, different types of fuel and oxidant, the flow rate of fuel and oxidant, and humidification temperature on the performance of the MEAs. It was shown that both the catalyst manufacturing process and the test procedure are repeatable. Also, it was shown that the performance of Pt-Ru cells when fueled by CO and CO-containing fuels was markedly inferior to that of hydrogen-fueled fuel cells. However, there were some promising signs that with the right catalysts and optimum operating conditions, the performance of DCMFCs can be significantly improved. It was also shown that increasing the operating temperature always improved the performance. While increasing the flow rates of the reactants improved the performance of the MEAs, there was a limit to this improvement. Furthermore, generally speaking, the performance of the MEAs was better when fed with CO rather than CO-N2 and O2 rather than air but the actual impact depended on other operating conditions.
Martin Andersson, Xinrong Lu, Jinliang Yuan et al.
ECS Transactions · 2011
In this study a two dimensional CFD (COMSOL Multiphysics) is employed to study the effect of anode microscopic structures on the transport phenomena and reactions for an anode-supported solid oxide fuel cell (SOFC). FCs can be considered as energy devices, involving multiple processes, such as (electro-) chemical reactions, heat exchange, gas- and ionic transport. All these complex processes are strongly integrated, needing modeling as an important tool to understand the couplings between mass-, heat-, momentum transport and chemical reactions. For the porous material, the Knudsen diffusion is taken into account in this study. The chemical- and electrochemical reaction rates depend on temperature, material structure, catalytic activity, degradation and partial pressure among others. It is found that the anode thickness and also the anode pore size need to be optimized to achieve high cell efficiency, when the Knudsen diffusion effects are included.
Sung Ho Cho, Woo Young Yoon
ECS Meeting Abstracts · 2016
Lithium Sulfur (Li-S) battery has a theoretically high specific capacity of 1675 mAh/g, which one of the most promising energy source for electric vehicles (EVs), hybrid electric vehicles (HEVs). However, Li-S batteries have problems resulting from the polysulfides dissolution into the electrolyte, volumetric extension of sulfur and insulating property of elemental sulfur. These causes make the loss of active materials and the capacity fading phenomenon. Even we address the as-mentioned issues, we necessarily encounter the formation of dendrite on the lithium metal anode. In our research, we use a lithium powder as an anode material to suppress the dendritic issue of lithium metal. The examination was conducted by comparing between the lithium foil and lithium powder. The cyclic voltammetry were tested at the scan rate of 0.1mV/s and 0.5mV/s with voltage range of 1.5V to 3.0V. Cells were tested at the current densities of 0.2 C-rate and 0.5 C-rate with 1.7V to 2.8V.
Zheng Li, Tianshou Zhao, Lin Zeng
ECS Meeting Abstracts · 2024
The "hydrogen society" concept has emerged as a response to the increasing demand for carbon-free energy and the aim of achieving "carbon neutrality". Proton exchange membrane fuel cells (PEMFCs) are considered the most promising hydrogen energy utilization units for commercialization, despite facing challenges related to durability and cost. One of the key obstacles is anode reversal, which inevitably occurs during the operation of PEMFC and significantly reduces performance, eventually leading to failure. Therefore, it is essential to investigate the mechanisms that affect anti-reversal performance and find effective strategies to improve reversal tolerance without compromising performance. Two approaches have been put forward. First, we aim to enhance the reversal tolerance of proton exchange membrane fuel cells (PEMFCs) by using polyaniline (PANI) coated carbon as a catalyst support. The PANI coating acts as a protective layer that isolates the carbon from the corrosive environment, resulting in improved anti-reversal performance. Moreover, the PANI coating helps to distribute the catalyst nanoparticles and ionomer uniformly, leading to enhanced polarization. We have tested various carbon supports to confirm the applicability of this coating strategy and optimized the thickness of the PANI coating to avoid any adverse effects on performance. Additionally, we have developed a high-specific-surface-area conductive oxide Ti 4 O 7 as an anode catalyst support to overcome the negative effects of carbon corrosion. By shortening the electron transfer pathway and increasing metal coverage, we have achieved comparable polarization performance to conventional carbon-supported counterparts. Our Ir@IrO x /Pt/Ti 4 O 7 -fabricated RTA has demonstrated approximately ten times longer reversal time (6 hours) and two orders of magnitude lower degradation rate than the conventional carbon-supported counterpart. These systematic studies aim to promote the development of highly durable and reversal-tolerant anodes, providing a promising outlook for practical, high-performance, low-degradation, and cost-effective RTA fabrication.
O. Horner, D. P. Wilkinson, E. L. Gyenge
Journal of The Electrochemical Society · 2024
Seawater electrolysis suffers from many issues that must be resolved before the technology can be scaled. The corrosive hypochlorite formation at the anode can damage the electrode and other electrolyzer components. Furthermore, hypochlorite is unstable and can decay, particularly when exposed to heat and metal ions, which could lead to erroneously high oxygen evolution reaction (OER) selectivity calculations in catalyst benchmarking experiments, resulting in poor catalyst and electrolyzer component selection. In this study, we used the rotating ring-disc electrode (RRDE) technique for the characterization of IrO 2 , NiO, Co 3 O 4 , RuO 2 , Pt/C, and PtRu electrocatalysts at near-neutral pH (8.4) in 0.5 M NaCl. The RRDE can overcome the challenge posed by thermocatalytic hypochlorite decay. IrO 2 and PtRu were also studied over a range of chloride concentrations from 0.1 to 1 M. Our findings reveal that elevated temperatures (313 and 333 K) are conducive to higher OER selectivity, as the OER faradaic efficiency (FE) on IrO 2 increased by 23% at 1.22 V vs SHE when the temperature was increased from 293 to 333 K. Increasing the chloride concentration from 0.1 to 1 M increased the OER current density by 40% and 200% on IrO 2 and PtRu, respectively, indicating a synergistic relationship.
Tianyu Cao, Yixiang Shi, Ningsheng Cai
ECS Meeting Abstracts · 2015
Liquid antimony is considered to be a promising anode for direct carbon fuel cell. The pilot system built in this research is made up with fuel supplement unit, cooling sub-system and power generating core block with tubular SOFC (solid oxide fuel cell) planted into liquid antimony bath. The metal bath serves as anode of direct carbon fuel cell and shall be fluidized during fuel cell operation. The fluidize wind acts as a carrier as well as a stirrer, for it carries pulverized coal directly into liquid antimony bath to feed the fuel cell before mixing the coal up with antimony anode. Well-stirred fluidized anode promotes the fuel cell performance, enhancing heat and mass transfer in the anode region, reducing the risk of thermal shock of tubular SOFC as well as accelerating the electrochemical oxidation of carbon fuel at the same time. The system exhibits stable performance during operation, and well-designed setup of liquid metal bath makes it much easier for stack assembly and system scale up, on the other hand, continuous fuel supply procedure employed in this system will also inspire direct carbon fuel cell operation in its future application. Figure 1
Tianyu Cao, Yixiang Shi, Ningsheng Cai
ECS Meeting Abstracts · 2017
Liquid tin has been widely employed as anodes in SOFCs to digest carbonaceous fuels. Liquid tin anode SOFCs fed on methane, kerosene, and carbon black have been successfully constructed and operated. However, the formation of a SnO 2 blocking film at electrochemical reactive sites hinders further electrochemical reaction and impedes steady power generation of the fuel cell system. Here we manage to suppress the formation of isolating SnO 2 film by anode fluidization. Tubular liquid tin anode SOFC has been fabricated and tested in present work. Fuels (H 2 and simulated syngas with different H 2 /CO ratio) are supplied to the electrochemical reactive interface between the anode and the electrolyte via a manner of bubbling bed. H 2 was found to effectively reduce SnO 2 formed when the SOFC was discharged at a constant potential of 0.45V, and anode fluidization has doubled the fuel cell’s power output. We anticipate that anode fluidization in this study will principally simplify the configuration of liquid tin anode SOFC and maintain the stable operation of the fuel cell system. Figure 1
Long Cheng, Yaxin Zhang, Dandan Li et al.
Advanced Functional Materials · 2026
Abstract Fast charging of high‐loading graphite anodes in lithium‐ion batteries (LIBs) is hampered by sluggish Li + ion transport kinetics, leading to detrimental Li dendrite formation and safety hazards. Herein, a copper‐based metal‐organic framework (Cu‐MOF) functionalized hydroxyapatite/bacterial cellulose (Cu‐MOF@HB) composite nanofibers separator is designed to address these critical challenges. The hierarchical porous structure of the Cu‐MOF@HB separator enhances electrolyte wettability and adsorption. Density functional theory (DFT) calculation reveals that abundant open metal sites within the Cu‐MOF promote PF 6 − anion immobilization via Lewis acid‐base interactions, effectively increasing the Li + ion transference number and facilitating faster Li + ion migration within the separator. Consequently, the Cu‐MOF@HB separator effectively mitigates concentration polarization at the graphite anode/separator interfaces, suppressing Li dendrite formation and improving Coulombic efficiency. This significantly improves fast‐charging performance in high‐loading LiFePO 4 (15.5 mg cm −2 )||graphite (7.5 mg cm −2 ) batteries, achieving 79% capacity retention after 600 cycles at 3 C, compared to only 16% with a conventional polypropylene (PP) separator. Critically, the Cu‐MOF@HB separator also exhibits exceptional thermal stability and flame retardancy, enhancing battery safety. This work highlights the significant potential of interfacial engineering of separators, particularly through the incorporation of functional MOFs and thermally stable inorganic nanofibers, for achieving safe and high‐performance fast‐charging LIBs.
Rodney G. Powers, Ivan R. Lasa, Michael T. Mather
CORROSION 2012 · 2012
Abstract Embedded sacrificial zinc anodes have emerged as a promising means of enhancing the durability of repairs to corrosion-deteriorated concrete structures. Sacrificial zinc anodes are encased in grout materials that are formulated with the intent of maintaining the zinc anode in an electrochemically active state. These grouts typically contain salts or humectants comprised of high pH media. Research has shown these grout additives to be capable of activating the zinc anode only on a limited, short-term basis. This paper discusses laboratory testing of a highly conductive proprietary grout material that has demonstrated capability to maintain long-term an electrochemically active state for both encapsulated zinc point anodes for localized repairs, and also in laminated surface-applied panels for large scale protection in either wet or dry zones.
Mani Pujitha Illa, Chandra Shekhar Sharma, Mudrika Khandelwal
ECS Meeting Abstracts · 2020
An ever increasing demand for high energy and high power rating Lithium-ion batteries (LIB) for electric hybrid vehicles persuaded the development of novel electrode materials with large storage capability and faster kinetic process. Carbon nanomaterials, owing to their unique and tunable physical and chemical properties, have been widely investigated as anode materials for LIBs. Diversified strategies involving the synthesis of carbon materials with hierarchical structures (morphology and porosity), and heteroatom doping have shown significant improvement in electrochemical performance of these carbon nanomaterials. In consideration to this, we hereby demonstrate the synthesis and utilization of hierarchical nitrogen-doped porous carbon structures derived from bacterial cellulose-polyaniline nano-composites as a promising anode material for LIBs. Microstructural analysis of the derived carbon revealed the inheritance of fibrous backbone as obtained from bacterial cellulose along with nano-granular structure of polyaniline. The structural and electrochemical properties of as-derived porous carbon structures are analysed systematically by performing XRD, Raman spectroscopy, XPS, cyclic voltammetry, galvanostatic charge/discharge studies and impedance spectroscopy. These results unveiled significantly large reversible capacities of 432, 233, and 127 mAh/g at 1, 5, and 10 C-rate respectively with excellent capacity retention. The energy and power densities of these hierarchical porous carbon structures were increased by 54% and 41% respectively when compared to pure bacterial cellulose derived carbon. This enhanced electrochemical performance may be attributed to the combined effect of interconnected micro-meso porous network of hard carbon along with nitrogen doping. The core-shell structure of this derived carbon accommodates the volume changes during lithium-ion insertion and de-insertion, rendering excellent cyclic stability even at high C rates without causing pulverization.
Illa Mani Pujitha, Mudrika Khandelwal, Chandra Shekhar Sharma
ECS Meeting Abstracts · 2018
Despite recent developments at lab-scale, Lithium ion is still fastest growing and most promising technology for rechargeable batteries. Although graphite has been conventionally used as anode materials in commercial Li ion batteries, a lot of other allotropes of carbon have also been explored in literature. Carbon nanofibers (CNF) based anode which are primarily derived from polymer precursors such as PAN, SU-8 negative photoresist, cellulose acetate is one such example. However, there is still a need to look for alternative precursors to yield CNF on commercial basis using a scalable, low-cost and sustainable route. Bacterial cellulose, a β-1,4 linked exopolysaccharide which is produced by some special kind of obligate aerobic bacteria is one such potential precursor. Bacterial cellulose which is devoid of lignin, hemicellulose and pectin unlike plant cellulose, comprises three-dimensional (3-D) inter woven nanofibrous network. Bacterial cellulose has several unique properties like higher degree of crystallinity, greater mechanical properties and modability. The fiber morphology and porosity of bacterial cellulose can be controlled to a great extent by employing different fermentation conditions, post treatment (drying and purification) and modifying the network formation by additives in fermentation media. Recent advances not only allows in-situ modification of bacterial cellulose properties using additives but also there are few reports on controlling the orientation and patterning of bacterial cellulose nanofibrils. However there are only few recent studies on exploring the bacterial cellulose as a polymer precursor to carbon upon controlled pyrolysis and to use them as anode. There is still a gap towards the integration of modifying the structural properties of bacterial cellulose and to correlate its effect on as-derived CNF and to further evaluate their electrochemical performance. This work is an effort toward this objective. In the present work, we will first discuss the fermentative production of bacterial cellulose, influence of bioprocess parameters and post production treatments on its physiochemical properties, followed by controlled pyrolysis to yield bacterial cellulose derived CNF. Average diameter of bacterial cellulose CNF was in the range of 20-50 nm. Depending on the fermentation media and growth conditions, crystallinity of bacterial cellulose and its derived carbon can be tuned to a great extent. These bacterial cellulose derived CNF were then used as an anode in half-cell configuration to investigate their electrochemical performance. We shall also present the way forward to explore the in-situ modification of bacterial cellulose to further provide a tight control on the physiochemical properties of CNFs upon pyrolysis with the perspective of their utilization as high performance anode for lithium-ion batteries. Given the scalability and relative low cost production of bacterial cellulose and as-derived CNFs may pave the way of their utilization for commercial electrodes in future. Figure 1
Poulomi Chandra, Anoop Verma, Aastha Palta et al.
Research Square · 2025
Abstract A novel electrooxidation (EO) unit was investigated for disinfecting wastewater, offering a promising alternative. This study continuously treated simulated bacterial wastewater using a mixed metal oxide (MMO) anode, mimicking hospital ward conditions. Optimal disinfection (96% bacterial inactivation) was achieved in continuous mode at a current density of 7.14 mA/cm 2 , 0.2 g/L NaCl, 9 minutes treatment time, and 40 mL/min flow rate. Real sewage wastewater achieved 92% inactivation at 8 minutes under these conditions. The MMO anode remained durable and effective after 300 cycles. EO presents a robust and affordable technology with an electrical consumption of 0.184 kWh/m 3 and an operational cost of $1.88/m 3 . These findings suggest this EO technique is a viable approach for decentralized wastewater treatment in hospital infectious wards, with the potential for real-world application.
Erik Lindemann, Inês Didier, Uwe Schröder
ChemElectroChem · 2025
In 1991, Habermann and Pommer published their work on a microbial fuel cell based on sulfide (S 2− ) mediation at cobalt hydroxide modified graphite anodes. Despite the promising character of the presented concept, literature does not show any follow‐up study or successful reproduction of the results. The common denominator among all further studies that involve sulfide oxidation is the working electrode: The use of plain graphite instead of cobalt impregnated graphite results in irreversible electrode blockage by build‐up of elemental sulfur ( S 0 ). In this—purely abiotic—study, the electrochemical properties of cobalt‐deposited electrodes are investigated when brought in contact with sulfide‐containing solutions. This study thereby shows that cobalt acts as a catalyst accelerating the oxidation of S 2− to higher oxidation products, thereby avoiding sulfur build‐up on the electrode surface. The sulfide oxidation can proceed directly at the cobalt oxide surface, or via a soaking and subsequent oxidation mechanism. In this process, the cobalt layer itself is “charged” by transformation to cobalt sulfide (CoS), which is subsequently “discharged” oxidatively resulting in the production of current. The insights presented here pave the way for a replication and utilization of the original results by Habermann and Pommer.
Carlo Santoro, Sofia Babanova, Baikun Li et al.
ECS Meeting Abstracts · 2014
MFC is a promising bio-electrochemical device capable of converting organic compounds (e.g. organic wastes) into useful electricity. In single chamber microbial fuel cells (SCMFCs), the anode is immersed in a solution containing organics that are oxidized and converted by the anodophillic bacteria attached at the anode, and the cathode is exposed to air for oxygen reduction reaction (ORR). As in nature, oxygen is the most preferable final electron acceptor due to its high reduction potential (~0.62 V vs Ag/AgCl at pH=7). The most common cathodes used in SCMFCs need noble catalyst (e.g. platinum) to achieve low overpotentials and subsequently high Open Circuit Potentials (OCP) of 0.3-0.4 V vs Ag/AgCl 1 . But even those cathodes often suffer severe potential losses especially at low current densities 2 . On the other hand, it has been found and routinely proved that air-breathing enzyme-based cathodes exploring birilubin oxidase (BOx) could achieve a cathode OCP higher than 0.5 V vs Ag/AgCl due to the low overpotential and high kinetics of the enzymatic catalyzed reactions 3 . The concept of a Hybrid MFCs had been previously proved and studied in two-chamber MFC 4 . For the first time, hybrid membraneless SCMFCs with microbial-based anode and enzyme-based cathode (BOx) were developed in this study and explored for high power generation. Air-breathing gas-diffusional cathode were prepared using 30%wt PTFE treated carbon cloth (Fuel Cell Earth) as current collector and cathode support. Teflonized carbon black (Vulcan XC72R with 35%wt PTFE was utilized as a gas-diffusional layer. The inner side of the teflonized carbon black (XC35) was additionally pretreated to achieve a gradient from hydrophobic to hydrophilic properties across the layer. The carbon cloth, the XC35 layer and a multi-walled nanotube paper (MWNTP) were fused together by hydraulic pressure. The MWNTP was used to support the catalytic layer on which BOx dissolved in phosphate buffer solution (PBS) was applied and then kept at 4 o C for 16 hours for enzyme immobilization. Membraneless and membrane-based (Nafion 117) SCMFC configuration was studied and compared in this experimentation. SCMFCs (volume of 130 ml) fed with PBS and NaOAc were run in a batch mode for a week. The batch mode SCMFC tests showed that the cathode OCP was higher than 0.5 V vs Ag/AgCl in all SCMFCs tested and stabilizes for an hour. The initial cathode polarization curves showed low overpotentials and ohmic resistances at low current generation (Figure 1a). All cathodes had significantly higher performances in comparison to the Pt-based cathode till 0.2 V vs. Ag/AgCl. Greater ohmic and mass-transfer losses during the cathode polarization were observed when a polymeric membrane (Nafion 117) was used. Markedly high power densities (referred to geometric cathode area) up to 200 μW/cm 2 (2 W/m 2 ) were reached in membraneless SCMFCs with PBS and sodium acetate (Figure 1b). When a polymeric membrane (Nafion 117) was applied in SCMFCs, the power generation dropped to 24-26 μW/cm 2 (0.24-0.26 W/m 2 ), which is most likely due to increased ohmic and diffusional losses given by the presence of a solid barrier. This study showed the possibility of using enzymatic cathode (bilirubin oxidase) in membraneless SCMFCs with high power generation. The highest power density (2 W/m 2 ) ever reported in a single bottle MFC fed with acetate in phosphate buffer was achieved in this study. The main problem related with the exploration of enzymatic electrodes in wastewater MFCs is the enzymes short lifetime and deactivation cased from contaminants in the wastewater. Further studies should be conducted in order to enhance the lifetime and the long-term operation efficiency of the developed enzymatic MFCs. References: 1 Zhang, F., Cheng, S., Pant, D., Van Bogaert, G., Logan B.E., (2009). Electrochemistry Communications, 11, 2177–2179 2 Rismani-Yazdia, H., Carverb, S.M., Christya, A.D., Tuovinen, O.H. (2008). Journal of Power Sources, 180, 683–694. 3 Higgins, S.R., Lau, C., Atanassov, P., Minteer, S.D., Cooney, M.J. (2011). ACS Catal., 1, 994–997 4 Ciniciato G.P.M.K., Lau, C., Cochrane, A., Sibbett, S.S., Gonzalez, E.R., Atanassov, P. (2012). Electrochimica Acta, 82, 208-213
Rachel Yoho, Bradley Lusk, Sudeep Popat et al.
ECS Meeting Abstracts · 2016
Anode-respiring bacteria (ARB) catalyze the complete oxidation of organic compounds (e.g. acetate, glucose) into electrical current and carbon dioxide. ARB naturally produce a biofilm at the electrode surface of up to 100 micrometers, where even cells on the outer part of the biofilm are participating in current production. The specific pathway by which ARB transport electrons intra- and extracellularly is still largely unknown. This is largely due to the fact that many ARB have redundant respiratory mechanisms, leading to a large set of possible proteins involved in these mechanisms. Our research utilizes a variety of electrochemical techniques in order to characterize electron transport responses from various ARB. Our goal is to provide insights into the possible mechanisms of electron transfer from the electrochemical responses of ARB biofilms. Through these experiments, we have observed a complex response to anode potential that allows ARB, such as G. sulfurreducens , to optimize their efficiency in electron transport. In G. sulfurreducens , two pathways were identified for anode respiration with midpoint potentials of – 0.155 ±0.005 and –0.095 ± 0.003 V versus SHE. G. sulfurreducens can shift between these two pathways depending on the anode potential in order to optimize its energy recovery from anode respiration. Pathway shifts were observed within 5-20 minutes of a shift in anode potential, suggesting that this microorganism has a potential-sensing mechanism. The fast shifts also confirm that the slow-scan cyclic voltammograms (~1 mV/s or slower) commonly performed in our field can be the result of transient responses by ARB, who can shift pathways within the experimental time. Multiple redox pathways have also been observed in thermophile T. ferriacetica and alkaliphile Geoalkalibacter ferrihydriticus , suggesting that most ARB can have multiple anode-respiration pathways. While the topic of electron transport is the focus of most ARB research, ionic transport is an important factor in determining rate-limiting and potential loss processes. ARB require near-neutral pH in the medium to grow, differing from chemical fuel cells commonly employed, which run under acidic or alkaline conditions. This pH requirement results in a major transport limitation, as H + ions (now in mM range) should be transported from anode to cathode to achieve electron neutrality. In an MXC anode, H + ions accumulate in the ARB biofilm, creating an acidification that limits current generation. This behavior has been observed with several ARB, including T. ferriacetica and Glk. ferrihydriticus . Through these experiments, we determined that the rate-limiting protein that is responsible for the potential response of ARB is a proton-coupled reaction. Experiments at different pH values result in shifts in the midpoint potential response of ARB, suggesting a proton coupled redox reaction. The specific stoichiometry of the reaction is difficult to elucidate since the H + accumulation in the biofilm causes a pH gradient. Nonetheless, our studies provide insights into the characteristics of the rate-limiting proteins in anode respiration which are yet to be identified.
Juan Esteban Velez, Carlos Sanchez
ECS Transactions · 2013
The electrical energy generation from biodegradable waste, has been gainingground due the growing demand of this resource and the environmental impactassociated. The latter creates a paradox, from one side we have the satisfaction of theenergy demand, in other hand we create a problem that in long term could be worst, forexample the contamination of the soil, air and water by the use of toxic products(petroleum, carbon, uranium, etc.) in order to satisfy the growing demand. In that way themicrobial fuel cells, try to solve both problems at the same time, generating electricalenergy by oxidation of waste water and treat it in the process, reducing the organicloading (8). However, this technology is far from be perfect, because of the low powergeneration, that is not near to satisfy the actual energy demand. This work is looking tomodel the anode of a MFC from thermodynamics of irreversible process theory thisbecause of the need to taking account the fluxes and forces behind the behavior showedby these devices that arise from the two thermodynamic laws, in order to theorize aboutthis phenomena and to define the most appropriate parameters that make possible anoptimal performance. The main goal of this work is to open a new methodology of designMFC to treat the water of streams in the metropolitan area of Medellin, emphasizing inthe improvement of the power level of the cell.
T. Ware, Dustin Simon, K. Hearon et al.
Macromolecular Materials and Engineering · 2012
Planar electronics processing methods have enabled neural interfaces to become more precise and deliver more information. However, this processing paradigm is inherently 2D and rigid. The resulting mechanical and geometrical mismatch at the biotic-abiotic interface can elicit an immune response that prevents effective stimulation. In this work, a thiol-ene/acrylate shape memory polymer is utilized to create 3D softening substrates for stimulation electrodes. This substrate system is shown to soften in vivo from more than 600 to 6 MPa. A nerve cuff electrode that coils around the vagus nerve in a rat and that drives neural activity is demonstrated.
O Abdelwahab, N Amin, E-S El-Ashtoukhy et al.
Global NEST Journal · 2021
Discharging wastewater from industries without any treatment causes environmental pollution and endangers biotic life. In this study, pollutant removal by electrocoagulation (EC) process was investigated using wastewater of the ore processing plant (magnesite crushing and screening plant). In the EC process, iron-iron and copper-copper electrodes were used in parallel in the reactor. Chemical oxygen demand (COD), Sulphate, Chromium (VI), Nickel, Zinc, Magnesium, and Total Suspended Solids (TSS) removals were investigated in the EC process of mineral processing industry wastewater with the iron electrode. These pollutants were calculated as %97.6, %95.1, %98.2, %98.1, %97.8, %88.2, and %98.9, respectively. COD, Sulphate, Chromium (VI), Nickel, Zinc, Magnesium, and TSS removals in the EC process of mineral processing industry wastewater with the copper electrode are %92.8, %94.9, %99.5, %98.7, %96.1, %91.6, and %96.9 respectively. It has been observed that high removal efficiency can be achieved by using the electrocoagulation process in the treatment of ore washing wastewater resulting from the crushing and screening processes in the Chrome Magnesite processing plant.
M. Chandel, P. Kumar, A. Arora et al.
Analytical Chemistry · 2022
Crop diseases cause the release of volatiles. Here, the use of an SnO2-based chemoresistive sensor for early diagnosis has been attempted. Ionone is one of the signature volatiles released by the enzymatic and nonenzymatic cleavage of carotene at the latent stage of some biotic stresses. To our knowledge, this is the first attempt at sensing volatiles with multiple oxidation sites, i.e., ionone (4 oxidation sites), from the phytovolatile library, to derive stronger signals at minimum concentrations. Further, the sensitivity was enhanced on an interdigitated electrode by the addition of platinum as the dopant for a favorable space charge layer and for surface island formation for reactive interface sites. The mechanistic influence of oxygen vacancy formation was studied through detailed density functional theory (DFT) calculations and reactive oxygen-assisted enhanced binding through X-ray photoelectron spectroscopy (XPS) analysis.
Lauren B. Kaiser-Jackson, Markus Dieser, M. McGlennen et al.
ECS Sensors Plus · 2023
During the growth of a polycrystalline ice lattice, microorganisms partition into veins, forming an ice vein network highly concentrated in salts and microbial cells. We used microfabricated electrochemical impedance spectroscopy (EIS) sensors to determine the effect of microorganisms on the electrochemical properties of ice. Solutions analyzed consisted of a 176 μS cm−1 conductivity solution, fluorescent beads, and Escherichia coli HB101-GFP to model biotic organisms. Impedance spectroscopy data were collected at −10 °C, −20 °C, and −25 °C within either ice veins or ice grains (i.e., no veins) spanning the sensors. After freezing, the fluorescent beads and E. coli were partitioned into the ice veins. The corresponding impedance data were discernibly different in the presence of ice veins and microbial impurities. The presence of microbial cells in ice veins was evident by decreased electrical characteristics (electrode polarization between electrode and ice matrix) relative to solid ice grains. Further, this electrochemical behavior was reversed in all bead-doped solutions, indicating that microbial processes influence sensor response. Linear mixed-effects models empirically corroborated the differences in polarization associated with the presence and absence of microbial cells in ice. We show that EIS has the potential to detect microbes in ice and differentiate between veins and solid grains.
R. A. Isibor, A. A. Olaojo, Adetoyese Yomi Oyelade
Ajayi Crowther Journal of Pure and Applied Sciences · 2023
Water is an essential resource for the sustainability of the human race and other biotic lives. This study emerged from variation observed in the groundwater distribution coupled with its quality within the Agudu neighbourhood. This investigation was centred on the geophysical and geochemical characterizations of the aquiferous units. Electrical resistivity method involving Vertical Electrical Sounding (VES) technique and geochemical assessment of groundwater were adopted for the study. A total of twenty VES points were occupied using the Schlumberger electrodes array and the current electrode separation (AB/2) ranged from 2 to 80 m. The data were subjected to both manual processing and computer base iteration using WinResist software. Twenty water samples were collected from wells across the community and subjected to physicochemical assessment. Flame photometry was used in analyzing the cations (Mg2+, Ca2+, Na+ , K+ ) while spectrophotometry was used for chloride, sulphate, bicarbonate, and nitrate. The VES sections revealed two to five geo-electric layers, the weathered and the fractured units were the aquiferous zones. The Dar-Zarrouk parameters were used in establishing the groundwater potential map and classifying the aquifer potential zones. The concentration of major cations was in the order Ca2+>Mg2+>Na+>K+ while that of anions were HCO3>Cl->SO4 -2>NO-3 . The pH values fall within the World Health Organisation’s recommended value, it ranged from slightly acidic to slightly alkaline. All the parameters fall within the permissible level except Ca2+ and water hardness at some locations. The techniques engaged were able to reveal the groundwater distribution and also characterised the chemistry of groundwater.
Ndepana Andrew, Anthony Trofe, Eric Laws et al.
Small · 2025
Abstract The chemistry of the extracellular electron transfer (EET) process in microorganisms can be understood by interfacing them with abiotic materials that act as external redox mediators. These mediators capture and transfer extracellular electrons through redox reactions, bridging the microorganism and the electrode surface. Understanding this charge transfer process is essential for designing biocapacitors capable of modulating and storing charge signatures as capacitance at the electrode interface. Herein, a novel biointerfacial strategy is presented to investigate directional charge injection from a non‐exoelectrogenic living microbe to an electrode surface using the porous metal–organic framework (MOF), MIL‐88B. The biohybrid, formed by interfacing Escherichia coli (E. coli) with MIL‐88B, demonstrates symbiotic interactions between the biotic and abiotic components, facilitating EET from E. coli to the electrode via the MOF. Acting as a redox mediator, the MOF catalyzes E. coli's exoelectrogenic activity, generating distinct charge capacitive signatures at the E. coli‐MOF interface. This system integrates the capacitive signatures resulting from the EET process with the MOF's intrinsic pseudocapacitive properties and surface‐controlled capacitive effects, functioning as a highly efficient biocapacitor. Furthermore, this approach of converting the biochemical energy of a non‐exoelectrogenic microorganism into capacitive signatures opens a new pathway for translating biological signals into functional outputs, paving the way for autonomous biosensing platforms.
Margot Jacquet, Miriam Izzo, Piotr Wróbel et al.
Materials Horizons · 2024
Solar-converting nanosystems using self-renewing biomaterial resources carry great potential for developing sustainable technologies to ameliorate climate change and minimize reliance on fossil fuels. By mimicking natural photosynthesis, diverse proof-of-concept biosolar systems have been used to produce green electricity, fuels and chemicals. Efforts so far have focused on optimizing light harvesting, biocatalyst loading and electron transfer (ET), however, the long-term performance of best-performing systems remains a major challenge due to the intensive use of diffusive, toxic mediators. To overcome this limitation, we developed a rationally designed nanosystem based on the entrapment of non-toxic mediator, ferrocene dimethanol (Fc), localized at the abiotic-biotic molecular interface that efficiently promoted ET between electrode surface and two photosynthetic proteins: cytochrome c and photosystem I. We demonstrate that space-confined Fc mediators (1 nM) are as effective in terms of ET kinetics as a 500 000-fold higher concentration of freely-diffusive Fc. The Fc-confined biophotocathodes showed a milestone photocurrent density of 14 μA cm-2 under oxic conditions compared to analogous planar (2D) biophotoelectrodes, with a photoconductive biolayer stable for over 5 months. The space-confined ET mediation reported in this work opens a new avenue for efficiently interfacing biomachineries, providing a benchmark design advancement in the quest for viable biohybrid technologies.
Jaehyoung Yun, Hyemin Kim, JungMin Kang et al.
ECS Meeting Abstracts · 2024
Over the last decade, various wearable sensor technologies that can monitor human health precisely in real time have extensively been developed. More recently, such wearable biosensor technologies have been employed to observe the condition of plants as well. In particular, a glucose sensor, which has been actively researched for diabetes, can also be applied to plants. A level of glucose concentration in plants indicates cellular metabolic status, biotic and abiotic stress of plants. However, unlike advanced glucose sensors for humans, early glucose sensors based on glucose oxidase are still used in plants glucose monitoring. The enzyme-based glucose sensor has several disadvantages including the stability problem due to denaturation of enzymes and difficulty of immobilizing enzymes on the electrode surface. Additionally, glucose oxidase needs a redox shuttle to transfer electrons, which complicate the sensor manufacturing process. Moreover, H2O2 is generated as a byproduct of glucose oxidase and glucose reaction, which can cause damage to plants and enzymes. In this study, non-enzymatic microneedle (MN) glucose sensor was developed using Co3O4 as a substitute for glucose oxidase. Co3O4 have electrocatalytic properties and chemical stability, showing higher sensitivity compared to glucose oxidase, and is suitable for long-term monitoring. However, it has the disadvantage of low electrical conductivity, making it difficult to transfer electrons, which are generated from the reaction with glucose, to a sensor electrode. Therefore, carbon nanomaterials were mixed to increase electron transfer efficiency and drop casted on the working electrode of a screen-printed sensor. To optimize the ratio of Co3O4 and carbon nanomaterials, the sensitivity was observed by comparing the peak current of cyclic voltammogram and saturation currents of amperogram according to each mixing ratio. Through the analysis results, it was confirmed that 17 wt% carbon nanomaterial had the highest sensitivity of 207 μA/mM cm2. Afterwards, a MN array sensor was fabricated to measure the glucose in plant leaves. MN can penetrate the epidermis of the leaf and enable to measure the glucose from near the phloem of the leaf. MN array structure was fabricated by dispensing SU-8 into a PDMS negative mold and cured by UV exposure. The working and reference electrode of MN array were coated with Co3O4/carbon composite and pseudo-Ag/AgCl ink, respectively, using a pneumatic 3D printer. Pt sputtering was conducted for forming the counter electrode. The metabolism of plants was confirmed by measuring the glucose concentration of leaves at day and night using a MN glucose sensor. References [1] Giraldo, Juan Pablo, et al. Nature nanotechnology 14.6 (2019): 541-553. [2] Teymourian, Hazhir, Abbas Barfidokht, and Joseph Wang. Chemical Society Reviews 49.21 (2020): 7671-7709. [3] Chen, Qianying, et al. Biomacromolecules 23.9 (2022): 3928-3935. [4] Harry, Micaela, et al. Sensing and Bio-Sensing Research 23 (2019): 100262. [5] Perdomo, Sammy A., et al. Biosensors and Bioelectronics 231 (2023): 115300. [6] Jiao, Kailong, et al. Royal Society Open Science 4.12 (2017): 170991.
A. M. Craven, G. Aiken, J. Ryan
Environmental Science & Technology · 2012
The ratio of copper to dissolved organic matter (DOM) is known to affect the strength of copper binding by DOM, but previous methods to determine the Cu(2+)-DOM binding strength have generally not measured binding constants over the same Cu:DOM ratios. In this study, we used a competitive ligand exchange-solid-phase extraction (CLE-SPE) method to determine conditional stability constants for Cu(2+)-DOM binding at pH 6.6 and 0.01 M ionic strength over a range of Cu:DOM ratios that bridge the detection windows of copper-ion-selective electrode and voltammetry measurements. As the Cu:DOM ratio increased from 0.0005 to 0.1 mg of Cu/mg of DOM, the measured conditional binding constant ((c)K(CuDOM)) decreased from 10(11.5) to 10(5.6) M(-1). A comparison of the binding constants measured by CLE-SPE with those measured by copper-ion-selective electrode and voltammetry demonstrates that the Cu:DOM ratio is an important factor controlling Cu(2+)-DOM binding strength even for DOM isolates of different types and different sources and for whole water samples. The results were modeled with Visual MINTEQ and compared to results from the biotic ligand model (BLM). The BLM was found to over-estimate Cu(2+) at low total copper concentrations and under-estimate Cu(2+) at high total copper concentrations.
D. Koutsouras, Leona V. Lingstedt, Katharina Lieberth et al.
Advanced Healthcare Materials · 2019
Electrodes coated with poly(3,4‐ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) have been employed to measure the integrity of cellular barriers. However, a systematic experimental study of the correlation between tissue integrity and impedance of the sensing device has not yet been conducted. Using impedance spectroscopy, how the impedance ratio of the biological tissue to the recording device affects the recording ability of the latter is investigated. PEDOT:PSS‐coated electrodes of various dimensions are employed and the effect of their size to their sensing efficiency is examined. The biotic/abiotic ensemble is modeled with a simple equivalent circuit and an analytical expression of the total impedance as a function of frequency is extracted. The results reveal a critical impedance ratio of the biological tissue to the sensor which allows for efficient sensing of the tissue integrity. This work provides the ground rules for improved impedance‐based biosensors with optimized sensitivity.
Ke Xu, Yinan Yang, Jianfei Ding et al.
Advanced Materials · 2024
The interface between electrodes and neural tissues plays a pivotal role in determining the efficacy and fidelity of neural activity recording and modulation. While considerable efforts have been made to improve the electrode‐tissue interface, the majority of studies have primarily concentrated on the development of biocompatible neural electrodes through abiotic materials and structural engineering. In this study, an approach is presented that seamlessly integrates abiotic and biotic engineering principles into the electrode‐tissue interface. Specifically, ultraflexible neural electrodes with short hairpin RNAs (shRNAs) designed to silence the expression of endogenous genes within neural tissues are combined. The system facilitates shRNA‐mediated knockdown of phosphatase and tensin homolog deleted on chromosome 10 (PTEN) and polypyrimidine tract‐binding protein 1 (PTBP1), two essential genes associated in neural survival/growth and neurogenesis, within specific cell populations located at the electrode‐tissue interface. Additionally, it is demonstrated that the downregulation of PTEN in neurons can result in an enlargement of neuronal cell bodies at the electrode‐tissue interface. Furthermore, the system enables long‐term monitoring of neuronal activities following PTEN knockdown in a mouse model of Parkinson's disease and traumatic brain injury. The system provides a versatile approach for genetically engineering the electrode‐tissue interface with unparalleled precision, paving the way for the development of regenerative electronics and next‐generation brain–machine interfaces.