Electrolytic Method Research Articles

INFLUENCE OF ELECTROLYSIS CONDITIONS ON THE COMPOSITION OF ELECTROLYTIC COMPOSITE COATINGS BASED ON COBALT

The composite coatings electrodeposition with the refractory metals with cobalt makes it possible to obtain a coating with a unique combination of physicochemical properties that are unattainable when using other application methods. One of the reasons for the limited use of the electrolytic method of coating with such composites is the difficulty of controlling the process. The properties of alloys of the iron subgroup with refractory metals and composites depend not only on the chemical composition (the content of the refractory component) but also on the deposition conditions. By varying the composition of the electrolyte in galvanostatic mode it is impossible to obtain high-quality composite coatings with a high content of refractory components and current efficiency. As an alternative, it was suggested the use of pulsed electrolysis mode that allows to improve the producing of composite coatings. The process of formation of composite electrolytic coatings based on cobalt Co-W-ZrO2 on a copper substrate in pulse mode with a diphosphate-citrate electrolyte was investigated. The effect of current density, pulse duration and frequency on the coating composition, surface morphology, and current efficiency of compositional electrolytic coatings based on cobalt with refractory metals. An increase in current density causes a decrease in the content of refractory metals in compositional electrolytic coatings and an increase in oxygen content. The resulting coatings differ in a uniformly developed surface without cracks, which provides a sufficiently high adhesion. It is established that the size of the globe on the surface of the alloy decreases with increasing current density to 10 A/dm2. The control of the composition of Co-W-ZrO2 galvanic alloys in a quite wide range of alloying components concentrations is being achieved by varying the parameters of the pulse electrolysis, which allows adapting of the deposition technology to the needs of the modern market.

Research Progress of Preparing Titanium Alloy By Molten Salt Method

Titanium alloy has excellent characteristics that cannot be compared with other metals such as light specific gravity, high specific strength, wide applicable temperature range, corrosion resistance, and hydrogen storage. The traditional titanium alloy smelting process is mainly based on titanium sponge as raw material, which has a long process, high energy consumption, heavy pollution, and other problems, which seriously restricts the sustainable development of titanium alloy in the world. The common methods of preparing titanium alloy are alloy melting, metal thermal reduction, powder metallurgy, and the gradually emerging molten salt electrolysis. Among them, molten salt electrolysis is recognized as the most promising method to replace the traditional titanium alloy production process, and certain achievements have been made in recent years in terms of both process and basic theory research. In this paper, the common processes of titanium alloy preparation by molten salt electrolysis at home and abroad, such as molten salt electrolytic co-deposition method, cathodic alloying method and liquid cathode method, new FFC method, and its derived SOM method, etc., will be summarized systematically, and the future research will be put forward.

Fe/Cu doped black ceramic coating on magnesium alloy by plasma electrolytic oxidation method based on first principles

The absorption of visible light by a solid material can correspond to its color. If all visible light is absorbed, the material is black, and the band width of the material defines the wave limit of visible light absorption. Based on this, the transition metal elements Fe and Cu were chosen to dope MgO, and the transition metal elements Fe or Cu were substituted to dope MgO using first-principles simulation. The doped elements' 3d and 4 s levels were introduced to shift the locations of MgO's valence and conduction bands, respectively, lowering the band gap width of MgO. The MgO ceramic coating may respond to light wave wavelength redshifting to 780 nm and entirely absorb visible light; The black MgO ceramic coating was prepared on the surface of AZ31 magnesium alloy utilizing Fe salt and Cu salt as plasma electrolytic oxidation (PEO) electrolyte additions, and the visible light absorption rates were 94.2 % and 94.1 %, respectively. The test findings show that the band gap of the MgO ceramic coating has been lowered from 4.97 eV to 1.58 eV and 1.60 eV, respectively, which is the primary reason for the achievement of strong absorption in all visible light bands. The first principle calculation of the influence of doping elements on the band gap of MgO ceramic coating can serve as a theoretical guidance for selecting coloring elements for the fabrication of black ceramic coating.

The role of graphene Oxide’s aromatic rings in activated carbon made from banana leaves (ACBL) and Fe3O4 in hydrogen production

Fe3O4 is an internal magnet that can work as a medium for the electrolyte solution in electrochemical hydrogen production to facilitate electron movement. When Fe3O4 is combined with activated carbon made from banana leaves (ACBL), electron transfer occurs between the ACBL aromatic ring and Fe3+ ions from solved Fe3O4, which increases the solution’s conductivity and finally produces more hydrogen. ACBL is a biomass catalyst used as a free parameter to increase the Fe3O4 magnetic field in the solution. The Fe3O4 was synthesized using the coprecipitation method, while ACBL was obtained through an activation process to produce graphene oxide. Graphene oxide in ACBL was characterized using Scanning Electron Microscopy (SEM) EDX, Fourier Transform Infra-Red (FTIR), Brunauer, Emmett, and Teller (BET), and TEM (Transmission Electron Microscopy). BET was used to determine the surface area of ACBL. Hydrogen was produced using the electrolysis method. The SEM results showed that the elemental content of graphene oxide in ACBL was 72.47 %. The graphene oxide in ACBL had a positive charge represented by a bright color on the sample surface. The positive charge was due to the FTIR O-H and C-O groups working with Fe3O4. BET analysis showed that the average pore diameter of ACBL was 1.68 nm. The largest hydrogen production results were obtained at ACBL 200 mesh, which was 15.5 ml. ACBL from abundant biomass has magnetic and electrical potential within its aromatic ring. As the aromatic ring interacts with the magnetic field of Fe3O4, the electromagnetic field of the solution is strengthened. As a result, hydrogen production increases.

Influence of Deep Etching Surface Treatment to The Tensile Strength and Microstructure of Brazing Aluminium - Mild Steel

Since hard metals are among the materials that liquid brazing alloys scarcely adhere to, they should not be brazed without first removing the surface layer after sintering. The electrolytic etching method, which gives the surfaces of materials that are hardly wettable very good energetic qualities, is given specific attention. Deep etching is done by using a high concentration of acid solution to roughen the surface. Both dry and wet settings are suitable for etching. An etching fluid is used for etching in a wet environment. Typically, the plate or metal is submerged in an etching solution, where the substance is chemically broken down. While in dry etching, the plasma’s gas phase is where the etching takes place. Due to the presence of plasma in this situation, the etching process that takes place combines chemical and physical processes. Plasma etching is another name for dry etching. Deep etching is an etching process to obtain a rougher surface. Wet deep etching requires a longer immersion time and even several immersions are required. The purpose of this study was to determine the effect of etching treatment in the brazing process of Aluminium-Mild steel for its microstructure and mechanical properties. The specimens in this study used aluminium 6000 series, mild steel, Alusol ER4043, and etching fluid. Mild steel surfaces are deep etched before brazing. Specimen manufacturing standard refers to ASTM D1002. A micro photo test was conducted to compare the surface conditions of aluminium and mild steel with and without etching treatment. The deep etching process is carried out in three variations of time, namely 20, 30, and 40 minutes. The results showed that the tensile strength increased with deep etching treatment on the surface.

TUDY OF THE INFLUENCE OF THE ACCUMULATED DOSE OF DAMAGE IN THE NEAR-SURFACE LAYER ON RESISTANCE TO EXTERNAL INFLUENCES ASSOCIATED WITH CORROSION PROCESSES DURING HIGH-TEMPERATURE ANNEALING

Abstract. Investigating the challenges associated with the structural and strength degradation of ceramic fuel cells, which hold significant potential for hydrogen production through electrolysis methods, is a current focus ofresearch. Understanding the degradation processes and their occurrence rate is crucial in the assessment of the efficacy of these ceramics for applications in alternative energy production, specifically in the realm of hydrogen energy. The aim of this study is to ascertain the impact of doping ceramics with aluminum nitride NiAl2O4, irradiated with protons with a dose of approximately 50 dpa, on resistance to high-temperature degradation, and associated corrosive processes of oxidation and swelling, as well as migration processes of implanted hydrogen. Three types of ceramics were selected as objects for study: NiAl2O4ceramics, NiAl2O4ceramics stabilized with 0.05 M AlN, NiAl2O4ceramics stabilized with 0.15 M AlN, that are distinguished by the formation of impurity phases in Al7O3N8, with an orthorhombic type of crystal lattice. As a result of high-temperature tests, it was observed that NiAl2O4ceramics, when stabilized, exhibit reduced susceptibility to destructive alterations in strength characteristics, primarily attributed to the deformation distortion of the crystal structure caused by its swelling. These processes are associated with an augmentation in the thermal expansion of the crystal structure, manifested in the deformation swelling of the crystal lattice volume.

Recovery of sulfuric acid and iron from titanium dioxide waste acid by membrane electrolysis combined with selective electrodialysis

The waste acid generated during the production of titanium dioxide contained a high proportion of ferrous ions. Comprehensive utilization of these waste acid involves the recovery of sulfuric acid and iron. However, traditional methods faced difficulty in attaining the desired outcome. Therefore, this study proposed a treatment process primarily based on membrane electrolysis. Initially, selective electrodialysis was employed to recover sulfuric acid from the waste acid. The effects of initial acid concentration, potential, and operating time on the performance of selective electrodialysis were investigated. Subsequently, a three-chamber membrane electrolysis method was utilized to oxidize Fe2+ to Fe3+ in the anode chamber and generate OH– in the cathode chamber. Both compounds were directed to the precipitation chamber through ion exchange membranes, resulting in the formation of iron hydroxide and the successful recovery of iron. The findings revealed that when the waste acid had a high initial concentration, it was recommended to operate at a higher potential. When treating 18 % of the waste acid, 77.5 % of the sulfuric acid can be recovered while 78 % of the ferrous ions were retained. As the acidity decreased, the potential could be reduced, resulting in a higher recovery rate of sulfuric acid and retention rate of Fe2+. By using a current of 150 mA during membrane electrolysis and maintaining a pH of 2.4 in the precipitation chamber, a purity of 94 % iron hydroxide was achieved. The ion flux of the anion exchange membrane decreased by 19 % after 8 h of electrolysis. This reduction could be mitigated by cleaning the membrane with titanium dioxide waste acid with a pH of 0.4 for 30 min. This study is expected to introduce innovative ideas and methods for the efficient and high-purity recovery of resources from titanium dioxide waste acid.

Continuous carbon fiber recycling technology using the electrolytic sulfuric acid method

Our objective is to achieve the societal implementation of the Circular Economy Program for Automobile Carbon Fibers. This involves recycling carbon fibers sourced from carbon fiber reinforced plastics/carbon fiber reinforced thermoplastics (CFRP/CFRTP) discarded from automobiles and reintegrating them into the manufacturing processes of automobiles. Although, the existing carbon fiber recycling technology recycles the carbon fiber into a finely chopped state; it is not the original continuous carbon fiber product. A novel recycling technology is elucidated herein, referred to as the electrolytic sulfuric acid method (ESAM). The ESAM recycles carbon fibers by decomposing only the resin component of CFRP/CFRTP into CO2 and water using oxidative active species generated by electrolytic sulfuric acid. This method can (1) be applied to all resins, (2) maintains strength of the recycled carbon fibers, and (3) regenerates continuous carbon fibers. Moreover, it is the only technology applicable to CFRP pressure tanks. The successful recycling of continuous carbon fiber from pressure tanks has been achieved, enabling the production of new tanks and unidirectional CFRTP tape. This technology recycles the original continuous carbon fiber product, thus enabling a “close” resource circulation cycle. We have not yet confirmed the number of times recycling can be performed. However, according to the method described in this paper, the recycling process can yield continuous carbon fibers without a decrease in physical properties. Therefore, theoretically, it becomes possible to recycle indefinitely and revert the fibers to their original state, provided that the strength reduction during product use is not a significant consideration.

Simultaneous extraction and separation of Ni(OH)2, Ni powder and Ni plate from waste nickel-cobalt scrap in one spot: Control sequence of electrical reduction

Extracting valuable metals from waste lithium-ion batteries is beneficial to the long-term growth of social economy and environmental maintenance from lithium-ion batteries, yet it faces serious challenges. The study aims to propose a harmless and efficient electrolysis method for selectively preparing nickel products from lithium-ion batteries leachate by controlling the competitive reductive order for Ni2+ and H2O. Compared with current pyrometallurgy, hydrometallurgy, and bio-metallurgy methods, electrolysis method allows selective preparation of different nickel products. No additional chemicals are introduced, or no membrane limitation. Achieving zero pollution emissions while saving costs. The results of serial experiments show that the level of nickel reduction can be controlled to produce different types of nickel products. The current efficiency reached a maximum value of 84.7±4.5%. 125 A/m2, 0.05 M Ni2+, 1.5 h, 60 A/m2, 0.1 M Ni2+, 2 h, 125 A/m2, 0.25 M Ni2+, 2 h are the optimal conditions for forming Ni(OH)2, black powder Ni and silvery flake Ni, respectively. In electrolysis process, selective nickel products, H2 and O2 can be prepared. H2 can be used as clean energy and increases economic benefits. This study provides a clean and high-efficiency method for selectively preparing nickel products from lithium-ion batteries leachate.

Utilizing reactive polysulfides flux Na2Sx for the synthesis of sulfide solid electrolytes for all-solid-state sodium batteries

Sulfide solid electrolytes are attractive for the development of all-solid-state sodium batteries owing to their high ionic conductivities and formability. While the performance related to ionic conductivity and additional functions is strongly influenced by composition and crystal polymorphs, the use of delicate and less stable sulfide starting materials limits their variability.In this study, we propose a universal and convenient synthesis method for sulfide solid electrolytes utilizing Na2Sx polysulfide flux as a stoichiometric reactant. These polysulfides mitigate synthetic constraints by eliminating the requirement for unstable sulfide starting materials. They efficiently react with raw materials, including single elements, under ambient pressure, without the necessity for a sealed reaction vessel.Na3BS3 glass, and Na2.88Sb0.88W0.12S4 solid electrolytes was prepared by using Na2Sx working as lowly volatile flux to prepare. Na2S and S immediately reacted with each other without sulfur vaporization, and stoichiometric Na2Sx liquid was formed at temperatures above 500 °C. The Na2Sx flux itself oxidized B, Sb, and W uniformly at moderate temperatures, and stoichiometric electrolytes were obtained in a one-step process without sealed vessels and a vacuum condition. In addition, Na3BS3 glass was produced by direct quenching at 700 °C. The obtained Na2.88Sb0.88W0.12S4 demonstrated the extremely high ionic conductivity of 125 mS cm−1 at 25 °C, due to the stoichiometric substitution of WS42−.

Electrochemical formation and characterization of Ni-Sc intermetallic compounds in LiF-CaF2 eutectic melt

The present investigation aimed to examine the cathodic behavior of Sc(III) on a reactive nickel electrode within a fluoride molten salt system. The electrochemical formation process of Ni-Sc alloy in LiF-CaF2 eutectic melt was investigated using cyclic voltammetry and square wave voltammetry electrochemical techniques. The formation of Ni-Sc intermetallic compounds induces a depolarization phenomenon, hence promoting the underpotential deposition of scandium onto the Ni electrode. The standard Gibbs free energy of formation for Ni-Sc intermetallic compounds were calculated by the use of open-circuit chronopotentiometry measurements. Furthermore, Ni-Sc alloys were fabricated via potentiostatic and galvanostatic electrolysis methods and subsequently characterized by X-ray diffraction, scanning electron microscopy, and energy-dispersive spectroscopy. The results indicated that a sequential emergence of Ni5Sc, Ni2Sc, and combined NiSc+NiSc2 intermetallic compounds escalates as the cathodic polarization potential. Multifarious Ni-Sc intermetallic compounds can be synthesized by controlling the electrolysis conditions, providing new insights for the preparation of Ni-Sc alloy and establishing a theoretical foundation for the synthesis of Ni-Sc intermediate alloy for solid-state reactive cathodes.

Modification of the surface of titanium alloys by the synthesis of coatings by the PEO method in alkaline electrolytes saturated with diatomite

One of the most promising directions of modern materials science is the search for methods of improving the biocompatibility properties of metals used in implantology, which will allow to reduce the percentage of rejection of implants by the living organism. Therefore, it is promising to use processing methods to change the state of the surface of metals due to surface modification, which includes the method of plasma electrolytic oxidation. The main goal of this work was to develop a technological process for obtaining coatings with higher biocompatibility compared to the base metal due to the introduction of natural components into the coating. The presence of elements in biocoatings and their quantity was determined using a scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDS), which allowed for targeted analysis of the surface of the samples. The elemental composition of coatings synthesised on the basis of titanium alloy in alkaline electrolytes based on KOH, liquid glass of calcium hydroxide, sodium polyphosphate and sodium pyrophosphate with the addition of hydroxyapatite and diatomite was researched in the work. A direct relationship between the composition of the electrolyte and the Ca/P ratio was established. It has been proven that biocoatings synthesised in alkaline solutions by the PEO method satisfy the conditions of biocompatibility. It has been established that in an environment containing alkalis and phosphates, coatings are synthesised for which Ca/P = 1.21. The introduction of hydroxyapatite into the electrolyte leads to an increase in the Ca/P ratio to a value of 1.28, and an increase in the concentration of the electrolyte and the addition of diatomite increases this ratio to a value of 1.57. The obtained results establish the possibility of a wide range of regulation of the Ca/P ratio in the biocoating

Pengolahan Lindi Tempat Pemprosesan Akhir Sampah Talang Gulo Dengan Metode Elektrolisis

The Talang Gulo control landfill waste final processing site (TPA) has been decommissioned and converted into a Sanitary Landfill TPA in the city of Jambi. Even though it has been deactivated, the waste resulting from the decomposition of waste at the TPA control landfill must be managed. One of the wastes that is managed is leachate. Before being released into the environment, leachate must be processed in leachate ponds so that the receiving environment is not polluted. Some of the leachate parameters that must be managed are mercury (Hg) and cadmium (Cd), because if these two parameters enter surface water they will have a negative impact on aquatic biota. The research is planned at the Batanghari University Engineering Laboratory. On a laboratory scale, the Hg and Cd parameters of leachate can be reduced using the electrolysis method. Electrolysis is an alternative method for processing leachate because the chemical reaction process using electrodes can reduce the Hg and Cd parameters. The hypothesis that can be taken is that the electrolysis method can reduce the Hg and Cd parameters of landfill leachate.

Электролизные растворы в санитарной обработке: прошлое и настоящее

New knowledge about biofilm microorganisms and their resistance needs new approaches to disinfection. The article traces the story of electrolysis, as well as inorganic chloractive and oxygen-active disinfectants. It describes the basic electrolysis scheme for obtaining salines and electrochemically activated substances. As a rule, their properties determine the target efficiency of the disinfectant. Certain electrochemical processes occur in anodic and cathodic chambers during electrolysis. They are associated with redox reactions of strongly adsorbed electroactive intermediate molecular forms obtained from water. They depend on the concentration of electrolyte in the solution, current power, electrolysis time, temperature, etc. The electrolytic method has good industrial prospects as it simultaneously produces chloractive anolyte solutions and alkaline catholyte solutions. They can be used as a complex for equipment sanitization purposes.

A Comprehensive Review on the Power Supply System of Hydrogen Production Electrolyzers for Future Integrated Energy Systems

Hydrogen energy is regarded as an ideal solution for addressing climate change issues and an indispensable part of future integrated energy systems. The most environmentally friendly hydrogen production method remains water electrolysis, where the electrolyzer constructs the physical interface between electrical energy and hydrogen energy. However, few articles have reviewed the electrolyzer from the perspective of power supply topology and control. This review is the first to discuss the positioning of the electrolyzer power supply in the future integrated energy system. The electrolyzer is reviewed from the perspective of the electrolysis method, the market, and the electrical interface modelling, reflecting the requirement of the electrolyzer for power supply. Various electrolyzer power supply topologies are studied and reviewed. Although the most widely used topology in the current hydrogen production industry is still single-stage AC/DC, the interleaved parallel LLC topology constructed by wideband gap power semiconductors and controlled by the zero-voltage switching algorithm has broad application prospects because of its advantages of high power density, high efficiency, fault tolerance, and low current ripple. Taking into account the development trend of the EL power supply, a hierarchical control framework is proposed as it can manage the operation performance of the power supply itself, the electrolyzer, the hydrogen energy domain, and the entire integrated energy system.

Morphology and Distribution of Primary Carbides in Forged Cr-Ni-Mo-V/Nb Steel.

This study aims to investigate in situ the three-dimensional (3D) morphology and distribution of primary carbides (PCs) in electro-slag remelting (ESR) forged 30Cr3Ni3Mo2V steel. A facile non-aqueous electrolytic etching method was applied to prepare 3D PCs on the matrix. The morphology, composition, and element concentrations of PCs were characterized using a combination of optical microscopy (OM), scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), and electron back-scattered diffusion (EBSD). The precipitation, type, and composition of PCs in the same steel were also simulated using Thermo-Calc software Version 2015a. The results indicate that PC is rich in Nb, which is a potential heterogeneous nucleating agent. Both the size and number of PCs increase from the edge to the center of the ingot. The large-sized PCs present three dominant types of morphology, which vary in different regions, i.e., a bulky type dominates in the edge region, a lamellar type dominates in the middle region, and a stripy type dominates in the core region. The results of EBSD analysis show that the orientation of PCs with different morphologies is different and that more nanosized V-rich type carbides are precipitated on the matrix. The thermodynamic calculations show that MC precipitates from the liquid phase when the solid phase fraction is greater than 0.985 and that the MC-type carbides are rich in Nb, which agrees well with the experimental results.

Study on ductile fracture behavior of hydrogen-charged API pipeline steel

With the increasing focus on reducing carbon emissions, hydrogen has emerged as a promising alternative energy source. However, the safe transportation of hydrogen poses challenges due to its potential impact on the integrity of pipeline materials. This study aims to investigate the effect of hydrogen charging time on the plastic behavior and ductile fracture characteristics of API 5L X42 pipelines, which are commonly used for transporting hydrocarbons. Tensile tests were conducted on various types of hydrogen-charged specimens at room temperature to assess different fracture modes. Hydrogen was introduced into the specimens using a cathodic electrolytic method, and 24-h charging time durations were considered. Finite element analyses were performed on standard dog-bone and notched tension specimens to evaluate the plastic behavior, employing the Swift hardening law to model the flow stress. Numerical analyses were conducted to determine the loading path leading to fracture initiation. A damage framework based on the Hosford–Coulomb model was utilized to predict ductile fracture under non-proportional loading conditions. The findings of this study provide insights into the fracture behavior of pipelines under hydrogen exposure, aiding in the design and assessment of safe and reliable hydrogen transport systems.

Optimasi Pemisahan Perak dari Limbah Fixer melalui Variasi Tegangan

Fixer solution is a chemical substance in the form of a concentrated liquid that is used to wash radiographic films. The Fixer Solution functions to dissolve the silver halide layer on unexposed radiographic films. This research aims to design a waste fixer solution processing device using the electrolysis method and to regulate the voltage to the optimal point to produce a large electrolysis rate. Design an electrolysis device using stainless steel electrodes with a trapezoidal cathode with parallel sides of the cathode with lengths of 170 mm, 145 mm and a cathode height of 155 mm. The anode is rectangular with a length of 30 mm and a height of 169 mm. The method for making tools goes through several stages, namely making tool designs, testing tools, and testing waste fixer solution. The fixer waste used comes from Betesdha Wonosari Hospital. In this research, each test used 5 liters of fixer waste at each voltage which was regulated for 3 hours. The higher the mass voltage produced, the higher the electrolysis rate will be. However, the higher the voltage, the faster the sulfidation process will be. In the design of this fixer waste management tool, it can work optimally at a voltage of 4 V with a speed of 4.87 g/hour.

Analysis of the Particle Size and Morphology of Tin Powder Synthesized by the Electrolytic Method.

This article discusses the effect of electrolysis parameters on the particle size and morphology of the tin powder synthesized by the electrolytic method. The electrolytic method is simple and can eliminate the risk of lead and arsenic gas emissions owing to the low temperature of the process. The effects of tin concentration in a sulfate-based electrolyte, a mass ratio of thiourea/gelatin as additives, current density, and electrolysis time on the particle size and morphology of the synthesized tin powder were examined. Pure tin and titanium plates were used as the anode and the cathode, respectively. After the electrolysis experiments were completed, the synthesized tin powders were analyzed by a particle size analyzer, a scanning electron microscope, and X-ray diffraction. The optimum condition of the experiment that resulted in the highest D90 was achieved at an initial concentration of SnSO4 = 3 g/L, a mass ratio of thiourea/gelatin = 1/4, a current density of 1 A/dm2, and a 10 min electrolysis time. Under this condition, 90% of the tin powder size obtained was smaller than 2.279 μm, showing a rounded morphology with a length-to-width ratio of 1.15. The current efficiency increased with increasing tin concentration, decreasing current density, and a shorter electrolysis time.

Low-level tritium measurements in freshwater and seawater samples

The aim of this study was to test two potential tritium determination methods (with and without electrolysis enrichment) suitable for low-level measurements. Both methodologies were applied to water samples from the Baltic Sea and ten Polish rivers providing new data on tritium activity concentration. Optimization steps carried out to the standard method lowered minimum detectable activity concentration (MDC) from 3.1 to 1.8 Bq L–1 (at 95% confidence level) enabling to apply it to environmental water samples. However, electrolytic enrichment method of MDC of 0.20 Bq L–1 provided more accurate results for tritium activity concentration in surface waters.