Cathode Solution Research Articles

Simultaneous electricity generation and sulfide removal via a dual chamber microbial fuel cell

Microbial fuel cells (MFCs) have recently been used to alter different sources of substrates to produce bioelectricity. MFCs can also be used for wastewater treatment and electricity generation simultaneously. Sulfur compounds such as sulfides commonly exist in wastewater and organic waste. In this study a dual chamber MFC was constructed for power production. Sulfide was used as the electron donor in the anaerobic anode compartment. A mixed culture of microorganisms was used as an active biocatalyst to convert the substrate into electricity. The obtained experimental results illustrated that the MFC can successfully alter sulfide to elementary sulfur while generating power. The initial concentration of sulfide in the anode compartment was 0.4 g l-1 and it was completely removed after 3 days of MFC operation. The influence of oxygen was examined in the cathode chamber and the cell voltage gradually increased during aeration, reaching 480 mV after 1200 s. Hexacyanoferrate was added to the cathodic solution in different concentrations and its effects were investigated. The maximum generated voltage, power and current density were 988.9145 mV, 346.746 mW.m-2, 1285.64 mA.m-2, respectively and they were obtained in the presence of 1.4 g l-1 of mediator.

Trace analysis of heavy metal ions in electroplate waste water by capillary electrophoresis with visual offline sample stacking via moving neutralization boundary

A moving neutralization boundary (MNB) was developed as a novel model of visual offline sample stacking for the trace analysis of heavy metal ions (HMIs) by capillary zone electrophoresis (CZE). In the stacking system, the motion direction of MNB to cathode was used with 2.1 mmol/L HCl-98 mmol/L KCl-trace metal ions in the anodic solution and 4.0 mmol/L NaOH-96 mmol/L KCl in the cathodic solution. The voltage was constant at 180 V and the flow rate of the anolyte and catholyte was 1 mL/min. The metal ions in the gel after stacking were detected by capillary electrophoresis. The calibration curves showed good linear relationship (r > or = 0.998 5) in the concentration range used in the experiments. The pre-concentration factors were up to 80 - 150 and the limits of detection (LODs) were 0.163, 0.256, 0.077, 0.153, 0.203, 0.062 and 0.142 mg/L for Cu(II), Zn(II), Ni(II), Mg(II), Ca(II), Cr(III) and Fe(III), respectively, obviously lower than the national standards. The intra-day and inter-day assay precisions were good (the relative standard deviations (RSDs) less than 7.42%). Finally, the developed method has been successfully used for the stacking and the detection of heavy metal ions in electroplate waste water.

A PbS Film Synthesized by Ultrasonic Wave Assisted Chemical Bath Deposition Method and its Application in Photoelectrochemical Cell

A Lead sulfide (PbS) film synthesized by ultrasonic wave assisted chemical bath deposition (CBD) method. The as-deposited films were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM) measurements. The photoelectrochemical (PEC) cell, with PbS/ITO/glass as a photo cathode and Na2SO4 (0.10 M) solution as an electrolyte, was constructed and investigated for PEC properties. The film shows a p-type conduction mechanism.

Localised corrosion and cathodic protection of 17 4PH propeller shafts

Some 17 4PH propeller shafts showed severe localised corrosion after a long period of time in Ancona harbour. The shaft is concentrically mounted in an AISI 304 stern tube through two rubber bearings. Both 17 4PH and AISI 304 stainless steels were characterised by anodic polarisation in natural sea water, in order to obtain the necessary corrosion parameters for designing a suitable cathodic protection of the propeller system. The cathodic protection effectiveness was tested on a portion (about 1 m long) of this system. Two cathodic protection methods were tested: an impressed current cathodic protection at −0·3 V(SCE) and a galvanic cathodic protection. The tests were performed both in stagnant and in moving sea water and the results showed that these cathodic protection solutions were able to protect the propeller system; in particular some guidelines are suggested for both old and new ships.

Effects of Periodic Electric Potential and Electrolyte Recirculation on Electrochemical Remediation of Contaminant Mixtures in Clayey Soils

This paper investigates the operational factors that affect an integrated electrochemical remediation (IECR) process for the degradation and removal of both organic and heavy metal contaminants in low permeability soils. IECR aims to degrade the organic contaminants through chemical oxidation process and at the same time remove the heavy metals through electromigration. Hydrogen peroxide is used as an oxidant which is transported into the soil by the electroosmotic flow. The natural iron in the soil acts as a catalyst for the decomposition of hydrogen peroxide in a Fenton-like process. Kaolin soil was used as model low permeability soil. Soil was polluted with phenanthrene and nickel at concentrations of 500 mg/kg each. Experiments were carried out at a constant voltage gradient of 1 VDC/cm using 10 % H2O2 as a flushing solution at the anode. The use of periodic voltage gradient and the recirculation of the cathodic solution to the anode favored the electroosmotic flow and the contaminant removal. Phenanthrene was eliminated from the soil in an average value of 30 %. Though electroosmotic flow was registered in all the experiments, negligible amount of phenanthrene was detected in the electrode solutions, confirming that the removal of phenanthrene is due to chemical oxidation. Nickel was solubilized and transported towards the cathode, but it was accumulated in the close vicinity of the cathode due to the high pH. Overall, this study showed that IECR has potential to remediate soils contaminated by both organic compounds and heavy metals.

A new advanced lithium ion battery: Combination of high performance amorphous columnar silicon thin film anode, 5 V LiNi0.5Mn1.5O4 spinel cathode and fluoroethylene carbonate-based electrolyte solution

A new advanced Li-ion battery comprising a high performance amorphous columnar silicon thin film anode, a high voltage LiNi0.5Mn1.5O4 spinel composite cathode and fluoroethylene carbonate (FEC)-based electrolyte solution (FEC/DMC 1:4 with 1M LiPF6) is reported. This advanced battery demonstrated hundreds of cycles, excellent charge–discharge efficiency and rate capability.

Modelling and Simulation of Double Chamber Microbial Fuel Cell: Cell Voltage, Power Density and Temperature Variation with Process Parameters

AbstractIn the present paper steady state models of a double chamber glucose glutamic acid microbial fuel cell (GGA-MFC) under continuous operation have been developed and solved using Matlab 2007 software. The experimental data reported in a recent literature has been used for the validation of the models. The present models give prediction on the cell voltage and cell power density with 19–44% errors, which is less (up to 20%) than the errors on the prediction of cell voltage made in some recent literature for the same MFC where the effects of the difference in pH and ionic conductivity between anodic and cathodic solutions on cell voltage were not incorporated in model equations. It also describes the changes in anodic and cathodic chamber temperature due to the increase in substrate concentration and cell current density. Temperature profile across the membrane thickness has also been studied.

Application of Assumed IVIVC in Product Life Cycle Management: A Case Study of Trimetazidine Dihydrochloride Extended Release Tablet

Microbial Fuel Cell (MFC) is a bio-electrochemical device used essentially for power generation and is now emerging as a sustainable waste treatment system. In this paper, we report detoxification of chromium VI contaminated water using algae biomass in a dual chamber salt bridge MFC. The device showed high chromium removal efficiency with 98% removal achieved in 96 h at pH 2. Initial pH of the cathode solution had a significant effect on device performance with acidic pH values favouring high chromium removal, Open Circuit Potential (OCV), power density and anodic COD removal. The power density value of 207 mW/m 2 and open circuit potential of 760 mV was attained at pH 2. Algae biomass driven MFC thus, proved to be an efficient bioremediation device with good power production.

Simultaneous Chromium Removal and Power Generation Using Algal Biomass in a Dual Chambered Salt Bridge Microbial Fuel Cell

Microbial Fuel Cell (MFC) is a bio-electrochemical device used essentially for power generation and is now emerging as a sustainable waste treatment system. In this paper, we report detoxification of chromium VI contaminated water using algae biomass in a dual chamber salt bridge MFC. The device showed high chromium removal efficiency with 98% removal achieved in 96 h at pH 2. Initial pH of the cathode solution had a significant effect on device performance with acidic pH values favouring high chromium removal, Open Circuit Potential (OCV), power density and anodic COD removal. The power density value of 207 mW/m 2 and open circuit potential of 760 mV was attained at pH 2. Algae biomass driven MFC thus, proved to be an efficient bioremediation device with good power production.

Using waste Li ion batteries as cathodes in rechargeable Li–liquid batteries

The rechargeable Li-liquid battery was developed using waste Li ion battery materials immersed in water and used as the liquid cathode. Either the Li metal or Li ions (by the formation LixC6 or Li(4+x)Ti5O12) was harvested from waste Li ion source materials such as a waste anode (LixC6), cathode (LixFePO4), and electrolyte (LiPF6 in EC:DEC) by charging the cell, which then discharged with the waste products in the liquid cathode solution to produce electric energy. When the Li4Ti5O12 was used as the anode with the waste products as the cathode in the proposed battery system, a good cycle-life with high coulombic efficiency was observed.

Effect of p-Type Semiconductor Electrode on Photovoltaic Properties in n/p Tandem-Type Dye-Sensitized Solar Cell

To improve the light-to-electric energy conversion efficiency of a dye-sensitized solar cell, a p-type semiconductor electrode was introduced to the cell so that n/p tandem-type solar cell was composed. In the tandem cell, the TiO2 adsorbed with N719 dye molecules and the p-type semiconductor were used an anode and a cathode, respectively, and acetonitrile solution containing iodide was done as an electrolyte. The cathode was prepared on a surface of platinum layer formed on a FTO glass plate by plasma spattering CuxBiyOz as the p-type semiconductor. Short-circuit current density and conversion efficiency of the tandem cell were larger than those in a cathode without the p-type semiconductor layer. The p-type semiconductor layer will be able to absorb low energy photons passed through the anode. After ZnO particles were coated on a surface of the p-type semiconductor layer, open-circuit voltage was increased. Such coating of the particles will be effective to depress a back-transfer at the interface between the p-type semiconductor layer and the electrolyte and band-bending of the p-type semiconductor.

Electricity generation from acidogenic food waste leachate using dual chamber mediator less microbial fuel cell

The acidogenic fermentation and electrochemical performance of mediator less dual chambered microbial fuel cell (MFC) with carbon electrodes for food waste leachate was studied. COD and pH of the food waste leachate were found 135.11 g/L and 3.93 respectively at the end of 58th day of fermentation. The potassium permanganate as a cathode solution with food waste leachate was the substrate source to an anodic chamber. After electrochemical evaluation of MFC for food waste leachate, it was observed that maximum 1.12 V open circuit voltage (OCV) was obtained for the COD load of 5000 mg/L. At optimum condition, MFC gave 66.75 A/m3 of current density and 15.14 W/m3 of power density along with the substrate removal of 90% in terms of COD. It was observed that ion exchange capacity (IEC) was reduced due to membrane fouling. The Scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR) analysis shows the deposition of microorganism and cations on fouled membrane, which significantly deteriorate the MFC performance. This study reveals the possibilities to reduce the quantity of food waste along with the production of bio-electricity.

Decolorization of an azo dye Orange G in microbial fuel cells using Fe(II)-EDTA catalyzed persulfate

This study constructed a microbial fuel cell (MFC) using Fe(II)-EDTA catalyzed persulfate as the cathode solutions to decolorize Orange G (OG) and harvest electricity simultaneously. Chelated Fe2+ could activate persulfate to generate sulfate free radicals (SO4-) which with high oxidation potential (E0=2.6V) can degrade azo dyes. The influence of some important factors such as pH value of cathode solutions, dosages of K2S2O8, Fe2+ and EDTA were investigated in a two-chamber microbial fuel cell. Under an optimal condition, the maximum power density achieved 91.1mWm−2, the OG removal rate was 97.4% and the K2S2O8 remaining rate was 47.3% after 12h. The OG degradation by Fe(II)-EDTA catalyzed persulfate was found to follow the second-order kinetic model.

Nitrate reduction with biotic and abiotic cathodes at various cell voltages in bioelectrochemical denitrification system

Electrochemical treatment of nitrate ions was attempted using different catalysts on the cathode in bioelectrochemical denitrification systems. The carbon cathode coated by biofilm (biocathode) could remove 91 % of nitrate ions at 1.0 V, which was almost same as the Pt-coated electrode (90 %). The exchange current density of biocathode was 0.0083 A/m(2), which was almost 22 times higher than with an abiotic plain carbon cathode. The formation of intermediate products in nitrate reduction varied depending on the cell voltage. At 0.5 V, a large portion of nitrate was converted to ammonia, but at more increased cell voltage (0.7 and 1 V) a high amount of nitrite ions was found with little ammonia formation in cathodic solution. The maximum nitrate removal rate was 0.204 mg NO(3)-N/cm(2)d by biocathode, while plain carbon paper showed only 0.176 mg NO(3)-N/cm(2)d. Electrochemical analysis of chronoamperometry showed a higher stable current generation for biocathode (3.1 mA) and Pt-coated cathode (2.8 mA) as compared to plain carbon (0.6 mA) at 0.7 V of poised voltage.

Water splitting with a dual photo-electrochemical cell and hybrid catalysis for enhanced solar energy utilization

This paper performs a thermodynamic analysis of a modified dual photo-electrochemical cell for water electrolysis, previously developed by Grätzel. In a typical Grätzel cell, a semi-transparent photo-electrode is used in conjunction with a dye photo-sensitized cell to generate a bias voltage necessary to overcome the inherent over-potentials caused by irreversibilities within the cell. The modified method implements hybrid photo-catalysis instead of heterogeneous catalysis. In the hybrid photo-catalysis approach, both homogeneous and heterogeneous photo-catalysts are used to enhance the speed of the water splitting reaction and to widen the portion of the solar radiation spectrum for the process. The dual cell consists of two tandem units. The first unit is a photo-electrolysis cell exposed to solar radiation (at both cathodic and anodic sides) via a transparent window, whereas the second unit is a dye-sensitized solar cell, which assists the photo-electrolysis cell. In the cathodic solution, there are dissolved Brewer-type supra-molecular complexes for photo-catalytic water reduction to generate hydrogen. They absorb solar radiation in the upper visible spectrum and dislocate multiple electrons at the active center. The complexes accept electrons donated from a GaP-based semi-transparent photo-cathode. The remaining un-absorbed radiation (mainly in the infrared range) crosses the semitransparent counter-electrode and the back glass. It is absorbed by a solar thermal collector for enhancing the solar radiation utilization by co-generating low-grade heat. The tandem cell with hybrid photo-catalysis has promising potential of improved solar radiation utilization. This paper analyzes the system efficiency and shows that 4% energy efficiency can be obtained for hydrogen generation. About 20% of the incident solar spectrum can be captured by the cell and used for hydrogen generation. Around 60% of solar radiation is recovered in the form of heat on a flat plate solar thermal collector placed behind the cell. The influence of catalyst concentration and pH also is studied. The device forms a four-gap solar absorber system, which is coupled to a cogeneration sub-system for heating, so the solar energy utilization is maximized. The four-gap system absorbs photons at 1.6, 2.1, 2.3, and 2.7 eV and generates five reversible potentials of 0.42, 0.9, 1.6, 2.1, and 2.3 V. Based on the predicted results, the reaction rate appears to be enhanced with respect to other solar electrolysis cells (such as photo-electrolyzers and a dual photo-electrochemical cell) because homogeneous catalysis enhances the electrode kinetics. Copyright © 2012 John Wiley & Sons, Ltd.

Electrokinetic remediation of dredged sediments polluted with heavy metals with different enhancing electrolytes

Electrokinetic removal of Cu, Zn, Cd, Cr, Pb and Ni from contaminated dredged material has been carried out on thirteen tests evaluating the effectiveness of different enhancing solutions of different nature (distilled water, citric acid, acetic acid, humic acid and EDTA). Several experimental variables were analyzed (type of enhancing solution, concentration, zeta potential, initial and final pH of the anolyte and catholyte, constants of chelation equilibriums (logβ) and precipitation (pKs), ionic mobility and charge density passed) and the main mechanisms of their action were critically analyzed. It was derived that there is not just one enhancing solution that is the best universal one for all the metals in the sediment and that modeling of the decontamination process should incorporate the particularities of the different species. However, as a generalization, it could be said that, apart from the charge density passed, the pH of the cathodic solution, quelation ability and the zeta potential seems to appear as the most relevant factors in the efficiency of the process.

Characterization of Bioelectrochemical Fuel Cell Fabricated With Agriculture Wastes and Surface Modified Electrode Materials

A bioelectrochemical fuel was fabricated with pretreated and fermented rice husks. The fuel was characterized with variation of process variables by determination of chemical oxygen demand (COD) which is a measure of the oxygen equivalent of electrochemically oxidizable organic fuel to produce electrical energy. The electrodes of the cell were made with nanoporous pure Al coated with platinum, platinum-ruthenium, and platinum-ruthenium-carbon. Anodization parameters were optimized by studying E-I characteristics in sulfuric and oxalic acids with variation of concentration and temperature. Pore size on the order of 30–50 nm was obtained by a two stage anodization. The performance of the cell was evaluated by determining open circuit potential, E-I characteristics, polarization studies, and cyclic voltammetry. A steady onload potential of 600–800 mV was obtained with current density on the order of 15–25 mA/cm2. High power density of 10–15 mW/cm2 has been obtained with electrode materials coated with Pt + Ru or Pt + Ru + C. The performance of coating on nanoporous structure was greatly reflected in the polarization studies, which showed a huge reduction of polarization resistance and increase of exchange current density by many times, the effect being more for anode with anodic solution, fermented rice husk, than with cathode with phosphate buffer cathodic solution. The surface morphology examined by SEM, showed nanodeposits of Pt, Pt-Ru, and the presence of carbon like structure. XRD peaks clearly reveal presence of Pt, Pt-Ru, and carbon.

Technical updates to basic proteins focalization using IPG strips

BackgroundGel-based proteomic is a popular and versatile method of global protein separation and quantification. However, separation of basic protein still represents technical challenges with recurrent problems of resolution and reproducibility.ResultsThree different protocols of protein loading were compared using MCF7 cells proteins. In-gel rehydration, cup-loading and paper-bridge loading were first compared using 6–11 IPG strips, as attempted, in-gel rehydration gave large horizontal steaking; paper-bridge loading displayed an interesting spot resolution, but with a predominant loss of material; cup-loading was selected as the most relevant method, but still needing improvement. Twelve cup-loading protocols were compared with various strip rehydration, and cathodic wick solutions. Destreak appeared as better than DTT for strip rehydration; the use of isopropanol gave no improvement. The best 2DE separation was observed with cathodic wicks filled with rehydration solution complemented with DTT. Paper-bridge loading was finally analyzed using non-limited samples, such as bovine milk. In this case, new spots of basic milk proteins were observed, with or without paper wicks.ConclusionAccording to this technical study of basic protein focalization with IPG strips, the cup-loading protocol clearly displayed the best resolution and reproducibility: strips were first rehydrated with standard solution, then proteins were cup-loaded with destreak reagent, and focalisation was performed with cathodic wicks filled with rehydration solution and DTT. Paper-bridge loading could be as well used, but preferentially with non-limited samples.

Peracetylated N-Acetylmannosamine, a Synthetic Sugar Molecule, Efficiently Rescues Muscle Phenotype and Biochemical Defects in Mouse Model of Sialic Acid-deficient Myopathy

Distal myopathy with rimmed vacuoles/hereditary inclusion body myopathy (DMRV/hIBM), characterized by progressive muscle atrophy, weakness, and degeneration, is due to mutations in GNE, a gene encoding a bifunctional enzyme critical in sialic acid biosynthesis. In the DMRV/hIBM mouse model, which exhibits hyposialylation in various tissues in addition to muscle atrophy, weakness, and degeneration, we recently have demonstrated that the myopathic phenotype was prevented by oral administration of N-acetylneuraminic acid, N-acetylmannosamine, and sialyllactose, underscoring the crucial role of hyposialylation in the disease pathomechanism. The choice for the preferred molecule, however, was limited probably by the complex pharmacokinetics of sialic acids and the lack of biomarkers that could clearly show dose response. To address these issues, we screened several synthetic sugar compounds that could increase sialylation more remarkably and allow demonstration of measurable effects in the DMRV/hIBM mice. In this study, we found that tetra-O-acetylated N-acetylmannosamine increased cell sialylation most efficiently, and in vivo evaluation in DMRV/hIBM mice revealed a more dramatic, measurable effect and improvement in muscle phenotype, enabling us to establish analysis of protein biomarkers that can be used for assessing response to treatment. Our results provide a proof of concept in sialic acid-related molecular therapy with synthetic monosaccharides.

Gold(III) recovery from non-toxic electrolytes using hybrid electrodialysis–electrolysis process

The process of gold(III) ions removal from hydrochloric solutions containing 0.01molL−1 HAuCl4 accompanied with metal electrodeposition from cathodic non-cyanide solutions is studied at galvanostatic electrodialysis. A possibility of gold(III) electrodeposition from 0.1molL−1 solutions of sulphuric, nitric, hydrochloric, perchloric acids and ammonia is demonstrated. The effects of the main electrodialysis parameters as well as of the composition of the cathodic solution on the gold(III) transport and electrodeposition rate are determined. It is shown that the gold(III) electrodeposition degree increases as the current density (0–6mA/cm2) and the process duration (0–3h) increase. The gold electrodeposits with good adhesion and of bright appearance are obtained in all studied systems.