Steel Electrodes Research Articles

Measurement and evaluation of cement paste porosity by electrochemical impedance spectroscopy

Porosity is an important part of cement paste microstructure, which significantly influences the mechanical properties (especially durability and strength) of cement-based materials. Electrochemical impedance spectroscopy (EIS) is a non-destructive method used to measure the pore system utilizing a range of frequencies of electric current, which is fed to the cement paste by stainless steel electrodes. The pore volume is obtained from the pore resistance and the matrix capacitance measured by EIS. This paper deals with the evaluation of porosity based on resistance values from EIS on a sample of pure CEM I 42.5R Portland cement paste at 3 different hydration times (age 7, 14, 28 days).

Removal of Boron from Simulated Iraqi Surface Water by Electrocoagulation Method

The removal of boron from aqueous solution was carried out by electrocoagulation (EC) using magnesium electrodes as anode and stainless steel electrodes as cathode. Several operating parameters on the removal efficiency of boron were investigated, such as initial pH, current density, initial boron ion concentration, NaCl concentration, spacing between electrodes, electrode material, and presence of carbonate concentration. The optimum removal efficiency of 91. 5 % was achieved at a current density of 3 mA/cm² and pH = 7 using (Mg/St. St. ) electrodes, within 45 min of operating time. The concentration of NaCl was o. 1 g/l with a 0.5cm spacing between the electrodes. First and second order rate equation were applied to study adsorption kinetics. The adsorption process follows second order kinetic model with good correlation. The energy consumption was evaluated for the optimum operating conditions. It was in the range of 1.296 to 1.944 Kwh/m3 . The overall expected increase in the operating cost of water treatment using membrane desalination facility (for example) will be about 20%.

Evaluation of peroxide assisted multi-oxidation systems for simultaneous removal of pharmaceutical active compounds from aqueous environment

This study aimed to evaluate the efficacy of peroxide assisted electro-chemical system (ECS) and photo-chemical system (PCS) in eliminating active pharmaceutical ingredients (APIs). Aluminum (Al) and stainless steel (SS) electrodes were used in ECS, whereas visible light (450–495 nm) was applied in PCS to remove acetaminophen (ACT) and ciprofloxacin (CIP) from both mono-component (ACT/CIP) and multi-component (ACT+CIP) systems. The study explored effect of operational parameters, kinetics, and energy requirements for removing APIs using ECS and PCS. The results showed that in ECS, Al electrodes outperformed SS electrodes with 95.15% removal of ACT and 95.52% removal of CIP using four Al electrodes at 15 V for 60 min. On the other hand, PCS at optimal conditions i.e. 16 W light intensity and FeSO4 and H2O2 dose of 0.5 g/L and 0.06 mL/L, respectively resulted in 85.25% ACT and 96.70% CIP removal. The kinetic study demonstrated that the removal of ACT and CIP through ECS followed second-order kinetics, while PCS followed a first-order model. In both ECS and PCS, ACT and CIP exhibited slightly higher removal efficiency in mono-component systems compared to multi-component systems. The EEO for removal of both APIs ranged from 0.05 to 0.3 kWh/kg in ECS and 3.9–15 kWh/kg in PCS. In general, peroxide assisted ECS and PCS both offer effective and efficient means for simultaneous removal of APIs from effluents.

Investigation of the effect of supporting electrolyte type and pH parameters on electrooxidation color removal from Direct Blue 86

In this study, color removal and electrical consumption from Direct Blue 86 (DB86) dyestuff, commonly used in the textile industry, were investigated using the electrooxidation method. A jacketed glass reactor with a volume of 2000 mL was preferred for the electrooxidation process. Five anode and five cathode electrodes with dimensions of 70 x 100 mm were used. Ti/IrO2/RuO2 was chosen as the anode material, and stainless steel (plate type) electrodes were preferred as the cathode. The effects of the supporting electrolyte type and pH parameters on color removal were investigated. NaCl, KCl, NaNO3, and Na2SO4 were used as supporting electrolytes. Experiments were conducted at pH 3, 5, 7, 9, and 11 with an applied current density of 0.325 mA/cm2. The results showed that KCl as the supporting electrolyte provided the highest color removal efficiency with 99.76%. The optimum pH value was found to be pH 9. The minimum energy consumption was calculated as 3.39 kW-h/m3 for pH 11. Based on the obtained results, it was concluded that the electrooxidation method is effective in color removal and can be preferred due to its ease of use and process control advantages.

Enhanced adsorption films of dendrimers on mild steel for super protection

ABSTRACT This study employed metronidazole skeletons based on the target branched molecules (TBMs) for achieving efficient anti-corrosion of mild steel in HCl solution. In contrast, the reference linear molecules (RLMs) carrying a single metronidazole framework were also made. The excellent corrosion resistance performance of the target dendrimers for mild steel electrodes in HCl solution was demonstrated. It is shown that the TBMs displayed a superior anti-corrosion effect for mild steel over RLMs in HCl medium at 298 K (at 0.15 mol/L, TBM1, 97.70% versus RLM1, 90.89%). It is shown that the standard Gibbs free energy changes of the adsorption of the TBMs on mild steel surface are below −33 kJ/mol (TBM1, −34.58 kJ/mol), thus an enhanced adsorption film was formed.

Treatment of Textile Dye Effluent Using Peroxi-Electrocoagulation

During recent years, industrialization has been under steady growth. Almost every Industry, uses water as one of their basic resources, due to which discharge of wastewater has also increased. One such industry is textile industry. There are various methods to treat these effluents. One of those methods is Peroxi-Electrocoagulation. This method is an advanced electrochemical oxidation process which involves principles of electrocoagulation and electrochemical oxidation by addition of hydrogen peroxide. The objective of this study is to treat textile dye effluent and find out the COD and Sulphate removal efficiency under different operational parameters. Key Words: Textile Effluent, Peroxi-Electrocoagulation, Stainless steel electrode, Hydrogen peroxide

Corrosion of Low-Carbon Steel in a Flow of Phosphoric Acid Solution Containing Iron(III) Phosphate

Theoretical aspects of low-carbon steel corrosion in H3PO4 solutions containing FePO4 are considered. In the system under study, reactions of iron with the acid solution and Fe(III) salt are thermodynamically allowed. The oxidizing power of this medium, characterized by the Fe(III)/Fe(II) couple redox potential, is mainly determined by its anionic composition. Phosphate anions of a corrosive medium bind Fe(III) cations into complex compounds, reducing their oxidizing ability. In H3PO4 solutions containing FePO4 and Fe3(PO4)2, the dependence of the system’s redox potential on the Fe(III) and Fe(II) cation relative content is poorly described by the Nernst equation, which is due to the nonequivalent complex formation of these cations with phosphate anions. Analysis of the effect of the studied media convection on the low-carbon steel electrode reactions allowed revealing some of their features. In a FePO4-containing H3PO4 solution, kinetically controlled partial reactions of iron anodic ionization and H+ cathodic reduction, as well as diffusion-controlled Fe(III) cation cathodic reduction, occur on the steel. The FePO4 accelerating effect on the steel corrosion in H3PO4 solution is due only to the Fe(III) reduction but does not affect the H+ reduction and the iron ionization. The value of the Fe(III)-cation diffusion coefficient in the studied corrosive medium was experimentally determined from the data of cyclic voltammetry of the Pt electrode therein and the results of the studying of the cathodic reaction of a steel disk electrode at different rotation velocities. The data on the low-carbon steel corrosion in the flow of the studied media, obtained from the metal samples mass loss, are in full agreement with the results of the study of the electrode partial reactions. An accelerating effect of FePO4 on the steel corrosion in H3PO4 solutions is observed. In this environment, steel corrosion is determined by the convective factor, which is typical of processes with diffusion control. The empirical dependence of the steel corrosion rate on the medium flow intensity is described by the linear dependence k = kst + λw1/2, where kst is the steel corrosion rate in a static medium, w is the rotation velocity of the propeller stirrer that creates the medium flow, λ is the empirical coefficient.

Engineered active pure water with reduced hydrogen bonds catalyzes itself in green energy production of oxygen and hydrogen evolution reactions

Noble metals, like platinum (Pt), palladium (Pd) and gold (Au), that possess special electronic configurations, are popularly used in renewable energy technologies of oxygen and hydrogen evolution reactions (OER and HER). Recently, approaches for renewable energies have focused on earth-abundant and cheap catalysts with different chemical compositions and structures. In this work, we propose an alternative strategy for OERs and HERs, focusing on water itself, utilizing Au-free condensed water (PAW-C) from heated trace Au-containing plasmon-activated water (PAW). Compared to active PAW, the electron-doping structure of PAW-C was reduced, while the degree of reduced hydrogen bonds (HBs) in PAW-C was enhanced. Encouragingly, compared to deionized water (DIW)-based 0.1 M KOH solutions, the measured current densities of OERs on a catalytic Pt electrode were significantly higher by average magnitudes of 45% and 23% for the PAW-C-based and PAW-based 0.1 M KOH solutions, respectively. Compared to the DIW-based 0.1 M H2SO4 solution, the measured current density of HER on a catalytic Pt electrode was significantly higher by an average magnitude of 20% for the PAW-C-based 0.1 M H2SO4 solution (an average higher magnitude of 15% for the PAW-based solution). Moreover, this proposed strategy was applicable to inert carbon and stainless steel electrodes for OERs. After aging for 3 days, the activity of the PAW-C of enhancing OERs was reduced by only ca. 5%. This fact indicates that its practical applications are promising. Active and stable PAW-C has emerged as a promising green solvent applicable to more-effective OERs and HERs.

Evaluation of corrosion resistance of Znx-Mn1-x coatings electrodeposited on 1020 carbon steel rotating electrode from choline chloride and urea at eutectic composition

Znx-Mn1-x coatings were successful electrodeposited on a rotating 1020 carbon steel electrode from an electroplating solution prepared by the mixture of choline chloride (ChCl) with urea (U) with the molar ratio of 1:2 (1ChCl:2U) and without the addition of additives. Their corrosion performances of the electrodeposited coatings were evaluated in 3.5% NaCl solution by open circuit potential (Eoc) monitoring, potentiodynamic polarization and linear polarization around Eoc. The chemical analysis of the electrodeposited coatings showed that the Mn electrodeposition was inhibited with the increase of the electrode rotation rate. The images of the surface morphologies showed that the increase in the rotation promoted grain refinement, producing more homogeneous surfaces with nodular grains. The X-ray diffraction patterns revealed crystalline structures with distinct phases of Zn and Mn, indicating the joint electrodeposition of Zn and Mn did not produce the formation of intermetallic phases. The Znx-Mn1-x coatings had better corrosion protective performance than the Zn coating. Finally, the Zn84Mn16 coating was best, presenting in the immersion tests a lifetime 3 times longer than the pure Zn coating.

2D and 3D electrochemical degradation (ECD) of raw cotton industry wastewater (CIWW) using stainless steel and aluminium electrodes.

Two-dimensional (2D) and three-dimensional (3D) batch electrochemical degradation (ECD) of raw cotton industry wastewater (CIWW) was adopted using stainless steel (SS) and aluminium (Al) electrodes. ECD as a treatment option was aimed at removing priority quality parameters, viz. chemical oxygen demand (COD), colour, chloride, nitrate, etc. COD removal of 85 and 80% were achieved by using 3D SS and 2D SS electrodes operated at 6 V (0.9 A) for a maximum electrolysis time (ET) of 30 min. Similarly, 76 and 70% COD removal were achieved for 3D Al and 2D Al electrodes, respectively. Simultaneous colour removal in the 2D ECD system using SS and Al electrodes was low by 12 and 11% compared to the 3D ECD system. Water quality parameters, viz. total dissolved solids, chloride, nitrate, phosphates, and sulphate were also removed by 3D (SS and Al) and 2D (SS and Al) electrodes. Higher pollutant removal efficiencies were observed at 30 min ET for 3D SS electrodes compared to 2D SS, 3D Al, and 2D Al. Post-ECD slurry showed good settling characteristics for SS electrodes generating dense and sturdy flocs giving a low sludge volume index values for 2D SS electrodes compared to other electrode options.

In-situ biogas enrichment using generated photovoltaic hydrogen

Hydrogen is the richest element in energy per unit of mass that exist. The challenge nowadays is its handling for different usages, as biogas upgrading. This research aims to study the behaviour of biogas upgrading with photovoltaic in-situ hydrogen generation with different type of substrates. It operates into batch reactors with 85 % of humidity of the mixture, with stainless steel electrodes at a controlled direct current voltage of 1.2 V at 38 °C, using pig slurry, chicken dung and rabbit poop (p > 0.05). Results showed a hydrogen generation during the process of 0.13 mol, 0.21 mol and 0.192 mol for pig slurry, chicken dung and rabbit poop, respectively. Leading to energy balance and energy recovery efficiency of 302.24 Wh.kg−1 and 12.45 %, 596.53 Wh.kg−1 and 19.99 %, and 1158.84 Wh.kg−1 and 30.33 % for pig slurry, chicken dung and rabbit poop, respectively. This upgrading technique improved biomethanization, but varied depending on substrate chemical characteristics involved.

Remediation of marine dead zones by enhancing microbial sulfide oxidation using electrodes

Marine dead zones caused by hypoxia have expanded over the last decades and pose a serious threat to coastal marine life. We tested sediment microbial fuel cells (SMFCs) for their potential to reduce the release of sulfide from sediments, in order to potentially protect the marine environment from the formation of such dead zones. Steel electrodes as well as charcoal-amended electrodes and corresponding non-connected controls of a size of together 24 m2 were installed in a marine harbour, and the effects on water quality were monitored for several months. Both pure steel electrodes and charcoal-amended electrodes were able to reduce sulfide concentrations in bottom water (92 % to 98 % reduction, in comparison to disconnected control steel electrodes). Also phosphate concentrations and ammonium were drastically reduced. SMFCs might be used to eliminate hypoxia at sites with high organic matter deposition and should be further investigated for this purpose.

Theta‐Gamma Phase‐Amplitude Coupling Deficit in Streptozotocin AD Rat Model

AbstractBackgroundTheta rhythms are known to encode sensory information and reflect their effect into gamma oscillations through a modulation process known as theta‐gamma phase‐amplitude coupling (PAC) (Amemiya et al., Cell Reports 2018). The role of the PAC as a network‐level indicator of cognitive impairment in disorders such as dementia and Alzheimer’s disease has received much attention recently (Zheng et al. Nature communication 2020).Injection of Streptozotocin (STZ) in animals is reported to cause resistance to insulin uptake in the brain, leading to memory and cognitive impairment (Kamat, Neural Regeneration Research 2015). The current study examines the induced deficit in the PAC as an early indicator of neurodegenerative effects of STZ.Method3 adult male Wistar rats were included in this study (270 – 300 g). Intraventricular injection of STZ was performed at a dose of 3 mg / Kg with a volume of 10 μl. Two stainless steel electrodes were implanted in the hippocampus (CA1) and medial prefrontal cortex (mPFC). The rats were free to move during recording. LFP data were recorded and segmented into windows of 20 s. Preprocessing and noisy trial rejection were employed for artifact removal, and the theta‐gamma PAC was measured using the mean vector length (tf‐MVL) method (Munia et al., Scientific Reports 2019).ResultOne week after STZ injection, the theta‐gamma PAC values did not show a significant change but after two weeks variation was observed. During this period, the power of different frequency bands was also measured and no significant change was observed even after two weeks. Theta‐gamma PAC deficiency was observed in both regions (CA1 and mPFC).ConclusionSTZ’s intracerebro‐ventricular injection is known to produce cognitive deficits along with an increase in Aβ deposition. This study reports that cross‐frequency coupling deficiency is also observed in this AD mouse model. Moreover, the PAC deficit was detected earlier than any change was observed in the spectral analysis of the data, suggesting that it can serve as a diagnosis tool for memory impairment due to neurodegeneration in the STZ mouse model of AD.

Synthesis and performance of a cathode catalyst derived from Bauhinia accuminata seed pods in single and stacked microbial fuel cell.

The cathode catalyst in microbial fuel cell (MFC) plays a crucial role in scaling up. Activity of biomass-derived activated carbon catalysts with appropriate precursor selection in a natural clay membrane-based MFC of 250mL was studied. The performance of scaled up MFC of 1.5L capacity with two different configurations was monitored. Rod-shaped particles with slit-type pores and amorphous graphitic nature with a surface area of 800.37m2/g was synthesized. The intrinsic doping of heteroatoms N and P in the catalyst was with atomic weight percentages of 4.5 and 3.5, respectively and the deconvolution of N1 spectra confirmed pyridinic N and graphitic N content of 17.3% and 34.1% validating its suitability as a cathode catalyst. Electrochemical characterization of the catalyst coated SS mesh electrode confirmed that a loading of 5mg/cm2 rendered higher catalytic activity compared to bare SS mesh. The maximum power density in catalyst modified cell was 0.91W/m3 compared to 0.02W/m3 as obtained in a plain stainless steel electrode cell at a COD removal efficiency of 93.3%. Series, parallel, and parallel-series combinations of 6 cells showed a maximum voltage of 4.15V when connected in series and a maximum power density of 1.54W/m3 when connected in parallel. System with multielectrode assembly achieved better power and current density (0.84W/m3 and 1.97A/m3) than the mixed parallel series circuitry (0.7W/m3 and 0.57A/m3). These performance results confirm that the catalyst is effective in both stacked and hydraulically connected system.

Affinity-based electrochemical biosensor with antifouling properties for detection of lysophosphatidic acid, a promising early-stage ovarian cancer biomarker

Electrochemical techniques are considered to be highly sensitive, capable of fast response and can be easily miniaturized, properties which can aid with regard to the fabrication of compact point-of-care medical devices; however, the main challenge in developing such a tool is overcoming a ubiquitous, problematic phenomenon known as non-specific adsorption (NSA). NSA is due to the fouling of non-target molecules in the blood on the recognition surface of the device. To overcome NSA, we have developed an affinity-based electrochemical biosensor using medical-grade stainless steel electrodes and following a unique and novel strategy using silane-based interfacial chemistry to detect lysophosphatidic acid (LPA), a highly promising biomarker, which was found to be elevated in 90 % of stage I OC patients and gradually increases as the disease progresses to later stages. The biorecognition surface was developed using the affinity-based gelsolin-actin system, which was previously investigated by our group to detect LPA using fluorescence spectroscopy. We demonstrate the capability of this label-free biosensor to detect LPA in goat serum with a detection limit of 0.7 µM as a proof-of-concept for the early diagnosis of ovarian cancer.

Blood-saving dissection with monopolar tungsten needle electrodes and Teflon-coated spatula electrodes in tumor orthopedics

IntroductionResection of musculoskeletal tumors and reconstruction with tumor endoprostheses often results in blood loss requiring transfusion of blood products. We assessed the blood-saving potential of using monopolar tungsten needle electrodes and polytetrafluoroethylene (PTFE)-coated spatula electrodes (intervention) compared with conventional dissection with sharp instruments and coagulation with uncoated steel electrodes (control).MethodsWe retrospectively analyzed data of 132 patients (79 interventions, 53 controls) undergoing surgery by one single experienced surgeon in our tertiary referral center between 2012 and 2021.ResultsIntraoperative blood loss in the intervention group was reduced by 29% [median (IQR): 700 (400–1200) vs 500 (200–700) ml; p = 0.0043]. Postoperative wound drainage decreased by 41% [median (IQR): 1230 (668–2041) vs 730 (450–1354) ml; p = 0.0080]. Additionally, patients in need of PRBCs during surgery declined from 43% to 15% (23/53 vs 12/79; p = 0.0005), while the transfusion rate after surgery did not change notably. The number of patients in need of revision surgery due to wound healing disorders was low in both groups (control group: 4/53 vs intervention group: 4/79). Only one patient in the control group and two patients in the intervention group underwent revision surgery due to hemorrhage. Baseline characteristics were similar between groups (sex, Charlson Comorbidity score, tumor entity).ConclusionDissection with tungsten needle electrodes and PTFE-coated spatula electrodes appears an effective surgical blood-saving measure without increased risk of wound healing disorders.Level of evidenceIII, retrospective comparative study.Clinical trial registration. The study was registered at ClinicalTrials.gov. Identifier: NCT05164809.

Hybrid Zinc Coatings with Chitosan/Alginate Encapsulated CuO-Nanoparticles for Anticorrosion and Antifouling Protection of Mild Steel

The construction of anticorrosion coatings containing antifouling agents is an effective way to ensure the long-term durability of marine steel infrastructures. In this work, an innovative hybrid coating was prepared by introducing biocide CuO nanoparticles in ordinary zinc coating to improve its protective ability for steel in aggressive salt water environments. The CuO nanoparticles were embedded inside the matrix of chitosan/alginate complexes to prevent spontaneous copper leaching during corrosive attacks. Two procedures were applied for the electrodeposition of hybrid/composite zinc-based coatings on low-carbon steel substrates (DC current): first—the co-electrodeposition of encapsulated CuO nanoparticles with zinc on a cathode (steel) electrode from a sulfate electrolyte with a relatively low pH value of about 4.5–5.0 and second—the encapsulated CuO nanoparticles were electrodeposited from aqueous solution as an intermediate layer between two zinc deposits. The particles size and stability of suspensions were evaluated using dynamic light scattering. Both hybrid coatings were compared in terms of surface morphology and hydrophilicity (SEM and AFM analysis, contact angle measurement) and corrosion resistance (potentiodynamic polarization curves, polarization resistance). The protective characteristics of the coatings were compared in a 3.5% NaCl solution and artificial sea water. The hybrid coating showed 2–4 times higher polarization resistance than the bare zinc coating during a 30 day immersion in artificial sea water, indicating that this coating has the necessary characteristics to be used in a marine environment.

Microbiologically influenced corrosion behavior of 304 stainless steel in ZnO nanofluids

Abstract The microbiologically influenced corrosion (MIC) behavior of 304 stainless steel by sulfate-reducing bacteria (SRB) in ZnO nanofluids was studied by electrochemical measurements, antibacterial activity tests and surface analysis. The results showed that ZnO nanoparticles (NPs) had little effect on the corrosion resistance of 304 stainless steel, but could effectively inhibit the MIC of stainless steel and reduce the adhesion of biofilm on its surface, which was related to the antibacterial effect of ZnO NPs. The antibacterial effect of 100 mg/L ZnO NPs reached 89.5 %. Electrochemical tests showed that with the increase of the concentration of ZnO NPs, the passive current density of the stainless steel electrode decreased, the film resistance increased in ZnO nanofluids containing SRB, and the MIC was inhibited. The antibacterial effect of ZnO NPs is mainly due to the formation of strongly oxidising ·OH in water. The presence of ZnO NPs inhibited the formation of biofilm and deposition of sulfide on stainless steel surface, thus slowing down the corrosion damage of SRB to stainless steel.

Treatment of debrominated wastewater by electrocoagulation using Mild Steel electrodes

Most process industries produce a large amount of effluent which includes bromine, which is valuable for further use. After the separation of valuable bromine from such industrial wastewater, a sizeable amount of debrominated wastewater (DWW) with a large amount of contaminates is left over. Considering the chemical oxygen demand (COD), total dissolved solid (TDS), turbidity, and color parameters, DWW cannot be discharged directly to water bodies. It mandatorily requires to be treated for the removal of various contaminants. Wastewater treatment includes traditional processes like chemical treatment, biological treatment, and physical treatment. Although they have been effective, each process has its limitations and can be energy-intensive and costly. Electrocoagulation (EC) is a highly effective treatment process that has been widely used to treat complex industrial wastewater. To treat DWW, The EC treatment was conducted in a 2-liter batch reactor using Mild Steel electrodes (MS) arranged as four parallel plates. After the treatment achieved maximum color, turbidity, COD, and TDS removal of 71.91%,100%, 36.36%, and 24.95%, respectively, at optimal current intensity 2 A, pH 9, and electrode spacing 1.5 cm. Energy consumption of 3 Wh/L was observed as a maximum at pH 11 and a maximum total metal consumption (TMC) of 2.11 g/L at pH 7. The highest foam and residue weight was 6.81 kg/m3 at pH 9 and the highest sedimentation rate was found at pH 11. Electrocoagulation treatment time was also examined for each parameter such as pH, electrode gap, and current intensity.

Electrochemical Reduction of K2MoO4–Fe2O3 Binary Melts Using a Consumable Steel Electrode to Produce Ferromolybdenum Alloys

Electrochemical Reduction of K2MoO4–Fe2O3 Binary Melts Using a Consumable Steel Electrode to Produce Ferromolybdenum Alloys