Study of the Susceptibility of Oxygen-Free Phosphorous Doped Copper to Corrosion in Simulated Groundwater in the Presence of Chloride and Sulfide

2006 ◽  
Vol 985 ◽  
Author(s):  
Ivan Escobar ◽  
Claudia Lamas ◽  
Lars Werme ◽  
Virginia Oversby
Keyword(s):  
Electrochemical Impedance ◽  
Copper Chloride ◽  
Chloride Concentration ◽  
Copper Surface ◽  
Chloride Ions ◽  
Transport Processes ◽  
Ion Concentration ◽  
Spent Fuel ◽  
High Concentration ◽  
Chloride Complexes

AbstractCopper of the quality oxygen free and high conductivity, doped with phosphorus (Cu OFP) has been chosen as the material for the fabrication of high level nuclear waste containers in Sweden. This material will be the corrosion barrier for spent fuel in the environment of a deep geological repository. It is planned that the service life of this container will be 100,000 years. During this time water with high concentration of chloride ions might come in contact with the copper surface. If pH conditions are appropriate, this might cause pitting corrosion. This work reports a study of the susceptibility of Cu OFP to corrosion when chloride ions are present, both deionized water (DW) and in standard synthetic underground water (SUW). The techniques used were electrochemical methods such as corrosion potential evolution and Tafel curves. In addition, this system was studied with Electrochemical Impedance Spectroscopy (EIS). We also used characterization techniques such as Scanning Electronic Microscopy (SEM), Energy Disperse Spectroscopy (EDS) . The main conclusions are that copper is more susceptible to corrosion at high chloride ion concentration. Additionally, when the chloride concentration is low, it is possible to form copper chloride crystals, but at the highest concentration, copper chloride complexes are formed, leaving the copper surface without deposits. When the chloride concentration is low (<0.1 M) the corrosion process is mainly controlled by diffusion, while at higher concentrations (0.1M to 1M) corrosion is controlled by transport processes. At low concentration of sulfide ( <3*10-5M), copper corrosion in the presence of chloride is controlled by diffusional processes.

scholarly journals A Study into the Localized Corrosion of Magnesium Alloy Magnox Al-80

CORROSION ◽  
10.5006/3574 ◽  
2020 ◽  
Author(s):  
Ronald Clark ◽  
James Humpage ◽  
Robert Burrows ◽  
Hugh Godfrey ◽  
Mustufa Sagir ◽  
...  
Keyword(s):  
Passive Film ◽  
Ph Dependence ◽  
Chloride Concentration ◽  
Ion Concentration ◽  
Localized Corrosion ◽  
High Concentration ◽  
Transfer Resistance ◽  
High Ph ◽  
Intact Surface ◽  
Chloride Concentrations

Magnesium (Mg) non-oxidizing alloy, known as Magnox, was historically used as a fuel cladding material for the first-generation of carbon dioxide (CO<sub>2</sub>) gas-cooled nuclear reactors in the UK. Waste Magnox is currently stored in cooling ponds, pending final disposal. The corrosion resistance of Mg and its alloys is relatively poor, compared to modern cladding materials such as zirconium (Zr) alloys, so it is important to have a knowledge of the chloride concentration/pH dependence on breakdown and localized corrosion characteristics prior to waste retrievals taking place. Our results show that Magnox exhibits passivity in high pH solutions, with charge transfer resistance and passive film thicknesses showing an increase with immersion time. When chloride is added to the system the higher pH maintains Magnox passivity, as shown through a combination of potentiodynamic and time-lapse/post corrosion imaging experiments. Potentiodynamic polarization of Magnox reveals a -229 mV<sup>-decade</sup> linear dependence of breakdown potential with chloride ion concentration. The use of the scanning vibrating electrode technique (SVET) enabled the localized corrosion characteristics to be followed. At high pH where Magnox is passive, at low chloride concentrations, the anodes which form predominantly couple to the visually intact surface in the vicinity of the anode. The high pH however means that visually intact Magnox in the vicinity of the anode is less prone to breakdown, restricting anode propagation such that they remain largely static. In high chloride concentrations the higher conductivity means that the anode and cathode can couple over greater distances and so propagation along the surface can occur at a much faster rate, with the visually intact surface acting as a distributed cathode. In addition, the chloride anion itself, when present at high concentration will play a role in rapid passive film dissolution, enabling rapid anode propagation.

scholarly journals The chloride effect in the human embryonic haemoglobins

1995 ◽  
Vol 309 (3) ◽  
pp. 959-962 ◽  
Author(s):  
O Hofmann ◽  
G Carrucan ◽  
N Robson ◽  
T Brittain
Keyword(s):  
Oxygen Affinity ◽  
Chloride Concentration ◽  
Chloride Ion ◽  
Chloride Ions ◽  
Ion Concentration ◽  
Chloride Binding ◽  
Independent Components ◽  
Binding Data ◽  
Chloride Effect ◽  
Allosteric Model

The interactions of the three human embryonic haemoglobins with chloride ions have been investigated. Each of the three embryonic haemoglobins exhibits a unique pattern of oxygen-affinity-dependence on chloride ion concentration. Human embryonic haemoglobin Portland (zeta 2 gamma 2) is found to be completely insensitive to chloride ion concentration. Haemoglobin Gower I (zeta 2 gamma 2) shows a small concentration dependence, whilst haemoglobin Gower II (alpha 2 epsilon 2) exhibits a dependence approaching that of the adult protein. The degree of co-operativity for each protein is essentially chloride concentration independent. The chloride-dependent and -independent components of the alkaline Bohr effects have been measured for each of the embryonic haemoglobins and compared with that of the adult protein. Both the chloride-binding data and the Bohr effect have been analysed in terms of the recently developed allosteric model proposed by Perutz [Perutz, Fermi, Poyart, Pagnier and Kister (1993) J. Mol. Biol. 233, 536-545].

scholarly journals Diffusion Behavior of Chloride Ions in Concrete Box Girder under the Influence of Load and Carbonation

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2117
Author(s):  
Yinglong Liu ◽  
Pengzhen Lin ◽  
Junjun Ma
Keyword(s):  
Coupling Effect ◽  
Chloride Concentration ◽  
Chloride Ion ◽  
Chloride Ions ◽  
Ion Concentration ◽  
Scale Model ◽  
Test Results ◽  
Box Girder ◽  
Concrete Box Girder ◽  
The Difference

In order to study the durability degradation characteristics of concrete box girder under load and carbonation and chloride ion erosion, a scale model of concrete box girder was made for experimental research. According to the test results, the diffusion characteristics of chloride ions in the concrete box girder under the coupling effect of load and carbon dioxide were analyzed. By revising the calculation formula of the existing chloride ion concentration considering multiple factors, a calculation model of chloride ion concentration considering the influence of carbonation was proposed, and the test results were verified. The results show that the chloride concentration of the box girder on the same cross section is non-uniformly distributed due to the shear lag effect and the spatial structure. After considering the effect of carbonation, the difference rate of the improved model proposed in this paper is generally within 10%. Compared with the original model, the difference rate is reduced by a maximum of 19%.

A Study of Uranyl (VI) Chloride Complexes in Aqueous Solutions under Hydrothermal Conditions using Raman Spectroscopy

MRS Advances ◽  
2020 ◽  
Vol 5 (51) ◽  
pp. 2623-2629
Author(s):  
Diwash Dhakal ◽  
Nadib Akram ◽  
Robert A. Mayanovic ◽  
Hakim Boukhalfa ◽  
Hongwu Xu
Keyword(s):  
Raman Spectroscopy ◽  
Nuclear Waste ◽  
Nuclear Reactor ◽  
Aqueous Media ◽  
Chloride Concentration ◽  
Spent Fuel ◽  
Hydrothermal Conditions ◽  
Chloride Complexes ◽  
Complex Species ◽  
Uranyl Chloride

ABSTRACTThe transport and deposition of uranium under hydrothermal conditions in the Earth’s crust has been a subject of ongoing study but is yet to be completely understood. In addition, there is little known about the fate of nuclear waste, consisting of uranium from spent fuel and other radioactive materials, upon storage in repositories or in nuclear reactor facilities. Because the nuclear waste often comes in contact with aqueous fluids in storage environments, studies of uranyl complexation with chloride and other ligands in aqueous media, to high temperature and pressure conditions, are needed. The primary purpose of this study was to investigate the speciation of aqueous uranyl (VI) chloride complexes, in solutions having a 0.05 M uranyl concentration and [Cl] concentrations ranging from 0.2 M to 6 M, under hydrothermal conditions. The aqueous uranyl chloride complexes in the samples were studied using Raman spectroscopy and the hydrothermal diamond anvil cell (HDAC), at temperatures up to 500 °C and pressures up to ~ 0.5 GPa. The uranyl bond stretching band feature occurring in the ~810 to 870 cm-1 region was fitted using the Voigt peak shape to determine the speciation of the equilibrium uranyl chloride complexes present in the samples. As expected, the n integer value of the UO2Cln+2-n complex species increases with the increase in temperature and chloride concentration, generally trending toward charge neutrality at high temperatures.

Pitting corrosion and effect of Euphorbia echinus extract on the corrosion behavior of AISI 321 stainless steel in chlorinated acid

2019 ◽  
Vol 37 (3) ◽  
pp. 259-271 ◽  
Author(s):  
Y. Koumya ◽  
R. Idouhli ◽  
M. Khadiri ◽  
A. Abouelfida ◽  
A. Aityoub ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Pitting Corrosion ◽  
Electrochemical Impedance ◽  
Chloride Concentration ◽  
Analysis Data ◽  
Chloride Ions ◽  
General Corrosion ◽  
Visible Absorption ◽  
Pitting Potential ◽  
Aisi 321

AbstractStainless steel (SS) is a very corrosion-resistant alloy used in different industrial plants because of its chemical and mechanical properties. However, the high chloride concentration in sulfuric acid (H2SO4) may promote both general corrosion and pitting corrosion. The pitting corrosion susceptibility in SS in chlorinated H2SO4 and the effect of Euphorbia echinus extract (EEE) on both general corrosion and pitting corrosion have been studied using potentiodynamic polarization, electrochemical impedance spectroscopy, chronoamperometry, cyclic voltammetry, and scanning electron microscopy (SEM). The pitting potential has been found to shift slightly in the presence of chloride ions (Cl−) in H2SO4. Also, pitting corrosion initiation has been demonstrated in the recorded chronoamperograms as a linear straight line having a positive slope. EEE has reduced the general corrosion and the inhibitor adsorption was found to follow the Langmuir isotherm. SEM micrographs showed that the tested inhibitor has efficiently acted on pitting corrosion for different concentrations of Cl−. Also, the kinetic findings were in good agreement with the surface analysis data. Fourier transform infrared spectroscopy and ultraviolet-visible absorption spectrophotometric measurements provided more insights on the interaction between the chemical functional groups of the inhibitor and the SS surface.

scholarly journals Effect of Nd3+ Ion Concentration on the Corrosion Resistance of API X70 Steel in Chloride-Rich Environments

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
D. M. Martinez de la Escalera ◽  
J. J. Ramos-Hernandez ◽  
E. Porcayo-Palafox ◽  
J. Porcayo-Calderon ◽  
J. G. Gonzalez-Rodriguez ◽  
...  
Keyword(s):  
Open Circuit Potential ◽  
Inhibition Efficiency ◽  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Protective Layer ◽  
Open Circuit ◽  
Chloride Ions ◽  
Ion Concentration ◽  
Linear Polarization Resistance ◽  
Potentiodynamic Polarization Curves

In this study, the effect of the addition of Nd3+ ions as a corrosion inhibitor of the API X70 steel in a medium rich in chlorides was evaluated. The performance of the Nd3+ ions was evaluated by means of electrochemical techniques such as potentiodynamic polarization curves, open circuit potential measurements, linear polarization resistance, and electrochemical impedance spectroscopy, as well as by means of scanning electron microscopy and EDS measurements. The results showed that Nd3+ ions reduce the corrosion rate of steel at concentrations as low as 0.001 M Nd3+. At higher concentrations, the inhibition efficiency was only slightly affected although the concentration of chloride ions was increased by the addition of the inhibitor. The adsorption of the Nd3+ ions promotes the formation of a protective layer of oxides/hydroxides on the metal surface, thereby reducing the exchange rate of electrons. Nd3+ ions act as a mixed inhibitor with a strong predominant cathodic effect.

scholarly journals Use of a Handheld X-ray Fluorescence Analyser to Quantify Chloride Ions In Situ: A Case Study of Structural Repair

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 571
Author(s):  
Servando Chinchón-Payá ◽  
Julio E. Torres Martín ◽  
Nuria Rebolledo Ramos ◽  
Javier Sánchez Montero
Keyword(s):  
Correction Factor ◽  
Chloride Concentration ◽  
Chloride Ion ◽  
Chloride Ions ◽  
Ion Concentration ◽  
X Ray ◽  
Structural Repair ◽  
Critical Areas ◽  
Different Depths

To ensure that a structure will last throughout its service life, repairing reinforced concrete entails, among others, correctly marking off the area affected by aggressive agents that may deteriorate both the concrete and the steel. Chloride, the most damaging source of reinforcement corrosion, may diffuse to a greater or lesser distance from the surface depending on the ease of penetration. In this study, we calibrated a handheld X-ray fluorescence analyser (hXRF) and used it to quantify the chloride concentration in cement-based materials. The findings were verified against a series of samples of known concentration to establish a suitable correction factor. Chloride ions were quantified precisely and accurately with the hXRF instrument, and we calculated a correction factor of 1.16. The instrument and the information recorded were used to quantify the chloride ion content in different parts of an existing structure. The analyser identified apparently healthy areas that could, nonetheless, pose oxidation problems in the near future due to significant chloride concentration. Chloride quantification data at different depths can be used to draw diffusion or penetration profiles and to determine whether ion concentration around the reinforcement is within the recommended limits. The method developed can be applied in situ to quickly locate the most critical areas.

scholarly journals How Sodium Chloride Concentration in the Nutrient Solution Influences the Mineral Composition of Tomato Leaves and Fruits

HortScience ◽  
2009 ◽  
Vol 44 (3) ◽  
pp. 707-711 ◽  
Author(s):  
Francesco Giuffrida ◽  
Marianna Martorana ◽  
Cherubino Leonardi
Keyword(s):  
Sodium Chloride ◽  
Nutrient Solution ◽  
Chloride Concentration ◽  
Linear Increase ◽  
Ion Concentration ◽  
High Concentration ◽  
Tomato Plants ◽  
Nacl Concentration ◽  
Electrical Conductivities ◽  
Linear Decline

Tomato plants (Solanum lycopersicum L. cv. Durinta) were grown in an open soilless system to evaluate the effects of sodium chloride (NaCl) concentration in the nutrient solution on the ion compositions in plant tissues. The treatments were defined by a factorial combination of five NaCl concentrations and three leaves position/age and two fruits' position. Seedlings were transplanted in perlite and, 7 days after transplanting, five salinity treatments were imposed by adding 7, 21, 37, 49, or 64 mm of NaCl to the nutrient solutions; the final electrical conductivities were: 2.7, 4.5, 6.0, 7.5, and 8.6 dS·m−1, respectively. Increased salinity in the nutrient solution resulted in a reduction in tomato dry matter (from 534 to 375 g per plant) and in a linear increase in sodium (from 0.37% to 1.39%) and chloride (from 1.75% to 5.73%) in the leaves as well as in the fruit tissues (from 0.08% to 0.26% for sodium and from 0.63% to 1.34% for chloride). Leaf under the first cluster showed higher levels of sodium (+54%) and chloride (+32%) than leaf under the fifth cluster and old leaf accumulated more sodium (+15%) and chloride (+25%) than younger ones. The exposure of the tomato plants to increasing salinity resulted in a linear decline in nitrate (from 1.21% to 0.50%), total nitrogen (from 3.31% to 3.03%), sulphate (from 3.71% to 3.12%), and potassium leaves (from 2.76% to 1.51%); the potassium reduction was more evident in younger leaves than in older ones. All macronutrients, except calcium, decreased in the fruit tissues with increasing NaCl concentration in the nutrient solution. However, for phosphate, the reduction of the ion concentration was evident only in the fruit from the fifth cluster (–35%). The position of the fruit on the plant significantly affected the concentration of ion, which was higher for all determined ions in the fruit of the first truss. The levels of Na+ and Cl– found in the plant tissue seem to confirm the hypothesis that the plant dry biomass reduction may also be traced to the toxicity of these ions as a consequence of this high concentration. On the other hand, although generally influenced by antagonism with sodium and chloride, the amount of main macronutrients did not reach deficiency levels that influenced the growth processes, except in the case of potassium.

A Critical Study of the Evidence for Peripheral Inhibitory Axons in Insects

1968 ◽  
Vol 49 (1) ◽  
pp. 201-222
Author(s):  
P. N. R. USHERWOOD
Keyword(s):  
Potassium Concentration ◽  
Chloride Concentration ◽  
Chloride Ions ◽  
Resting Potential ◽  
Equilibrium Potential ◽  
Critical Study ◽  
Muscle Fibres ◽  
High Concentration ◽  
Bathing Medium

1. The metathoracic anterior coxal adductor (a.c.a.) muscle of the locust and the grasshopper is innervated by a peripheral inhibitory axon similar to the inhibitory axon which innervates the metathoracic extensor tibiae muscles of these insects. No evidence was found to justify calling this axon an inhibitory-conditioning axon. 2. Hyperpolarizing inhibitory postsynaptic potentials (IPSPs) are normally recorded from a.c.a. muscle fibres during stimulation of this axon, and if the bathing medium contains a high concentration of potassium ions the tonic fibres of the a.c.a. muscle relax slightly during inhibitory stimulation. 3. The IPSPs are chloride potentials and can be converted to depolarizing responses by changing either the external or internal chloride concentration of the a.c.a. muscle fibres. Depolarizing IPSPs are frequently accompanied by small contractions of a.c.a. muscle fibres innervated by the inhibitory axon. 4. The a.c.a. muscle fibres are permeable to potassium and chloride ions but influx of potassium chloride is much faster than efflux. Therefore when a.c.a. muscle fibres are loaded with chloride by exposing them to high-K saline (20-100 m-equiv. potassium/l.) and are then returned to normal (10 m-equiv. potassium/l.) saline the internal chloride concentration remains elevated for some time and during this period the equilibrium potential for the inhibitory response is less negative than the resting potential and the IPSPs are depolarizing. 5. Depolarizing IPSPs are usually recorded from a.c.a. muscle fibres of locusts and grasshoppers when these fibres are transferred from their normal bathing medium, haemolymph, to 10 K saline. Probably the main reason for this reversal of the IPSPs is the entry of KCl into the muscle fibres during dissection of the nerve-muscle preparations. Large quantities of KCl would be released into the environment surrounding these preparations from muscle fibres cut and removed during dissection. 6.Depolarizing IPSPs were more frequently recorded from muscle fibres of grassfed locusts than from fibres of starved locusts. The potassium concentration of haemolymph of grass fed locusts is higher than that of locust saline (10 m-equiv./l.). 7. The potassium concentration of locust haemolymph presumably fluctuates in vivo but these fluctuations are too slow to affect the sign of the IPSP. The IPSPs are therefore always hyperpolarizing in vivo. 8. The effect of changes in the potassium concentration of the bathing medium on the magnitude and polarity of the IPSP could account for the diverse responses recorded previously from a.c.a. muscle fibres of locusts and grasshoppers.

Electrochemistry of High Concentration Copper Chloride Complexes

2013 ◽  
Vol 85 (16) ◽  
pp. 7696-7703 ◽  
Author(s):  
Hong Zhao ◽  
Jinho Chang ◽  
Aliaksei Boika ◽  
Allen J. Bard
Keyword(s):  
Copper Chloride ◽  
High Concentration ◽  
Chloride Complexes
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