Chloride Media Research Articles

Application of a new TOPO-Cuprone type V deep eutectic solvent as a carrier of Zn(II), Cd(II), Pb(II) and Cu(II) ions in polymer inclusion membranes. Chemometric methods for new hydrogen bond acceptor (HBA) selection

A new hydrogen bond donor was selected as a deep eutectic solvent (DES) component using 0D, 1D, and 2D molecular descriptors and chemometric methods such as hierarchical cluster analysis (HCA) and principal component analysis (PCA). Compared to typical substances used as hydrogen bond donors (HBDs), namely carboxylic acids, it was found that α-benzoin oxime (Cuprone), despite of its different properties, is also a suitable DES constituent. A new DES was synthesized and applied as a carrier of Zn(II), Cd(II), Pb(II), and Cu(II) ions in polymer inclusion membranes (PIMs). Tri n-octyl phosphine oxide (TOPO) was applied as a hydrogen bond acceptor (HBA), and Cuprone was used as the HBD in the 2:1 M ratio, respectively. The transport properties of a new DES were compared with PIM systems in which TOPO:benzoic acid, TOPO:dodecanoic acid, and pure TOPO were applied. The selected physicochemical properties such as density, viscosity, and thermal stability of the new DES were examined. The transport and separation of Cd(II), Zn(II), Pb(II), and Cu(II) ions from chloride media using a new DES as a carrier were investigated. The influence of the carrier content and the presence of a plasticizer on transport efficiency during long-lasting experiments were also examined.It was found that the observed membrane transport selectivity order Zn(II) > Cd(II) > Pb(II)≫Cu(II) results from the presence of TOPO in the newly prepared DES. Moreover, systems with a plasticizer exhibit high operational stability during long–term experiments lasting over 500 h. Some drawbacks which appeared during the transport experiments were noticed and described in detail.

Corrosion inhibition performance of expired amlodipine on cupronickel alloy in a neutral chloride environment: electrochemical and surface analysis

Purpose The corrosion of cupronickel and copper alloys in marine and chloride environments presents significant challenges in the chemical and petrochemical industries. This paper aims to investigate the corrosion inhibition of cupronickel alloy (Cu-10Ni) in a sodium chloride medium using expired amlodipine as a corrosion inhibitor. The use of this drug in its expired form could reduce the costs of corrosion and help mitigate the accumulation of pharmaceutical waste. Design/methodology/approach The inhibitory action was evaluated using a weight loss method, potentiodynamic polarization, electrochemical impedance spectroscopy measurements, scanning electron microscopy (SEM) and atomic force microscopy (AFM). The effect of temperature on the inhibition performance was also studied. Findings The results of these experiments demonstrated that the drug amlodipine effectively inhibited the corrosion of cupronickel alloy in chloride solutions. The corrosion rate of cupronickel was found to decrease with increasing inhibitor concentration and to increase with rising temperature. A maximum inhibition efficiency of 91.92 was achieved with an inhibitor concentration of 0.025 g/L at 298 K. Adsorption of the inhibitor followed the Langmuir adsorption isotherm. Polarization studies indicated that the expired drug acted as a mixed inhibitor. SEM and AFM analyses confirmed that the surface morphology of cupronickel specimens was significantly improved in the presence of the inhibitor. Practical implications Amlodipine can be conveniently used to mitigate problems with the corrosion of copper alloys in chloride environments. Originality/value Amlodipine is evaluated as a novel and effective corrosion inhibitor for cupronickel alloy in neutral chloride environments.

Liquid-liquid extraction and separation of light and heavy rare earth elements from chloride solution using a mixture of tertiary amine and phosphinic acid: recycling strategies for NdFeB magnet

ABSTRACT This piece of work aims to study the extraction behavior of light and heavy rare earth elements, which are often found in permanent magnets, using a mixture of tri-octyl amine and bis-(2,4,4-trimethylpentyl) phosphinic acid from a chloride medium. The study showed that the extraction efficiency of Dy(III) is more than that of Nd(III) and Pr(III). Benzene proved to be an effective diluent. Increasing the pH of the aqueous phase improved the extraction percentages, with maximum extractions of 98.4% for Dy(III), 61.2% for Nd(III), and 58.3% for Pr(III) at pH 5.04 using 0.1 mol/L of each extractant. Adding sodium chloride enhanced the extraction efficiency due to the salting-out effect. The extraction mechanism has been proposed based on the slope analysis and FTIR data. From thermodynamic variables, the process was found to be exothermic. The simulated leach liquor of NdFeB magnets showed the highest separation factors of 67.7 (Dy/Pr) and 56.9 (Dy/Nd) at pH 2.05 with 0.25 mol/L extractants. The counter-current study showed that 4.15 mg/L Dy(III) was left behind in the raffinate indicating 97.4% removal of Dy(III) in two stages at unity phase ratio. Testing with actual leach liquor from hard disk magnets revealed a preference for iron extraction, which impeded REE extraction.

Lipophilic EDTA-based ligands in different diluents for the extraction of rare earths: Preliminary results with Nd(III), Dy(III) and Pr(III) in chloride and nitrate media

A separation method for the recovery of neodymium(III) from two different media, chloride and nitrate, by implementing solvent extraction technique with a novel lipophilic diamide derivative of ethylenediamine tetraacetic acid (EDTA), namely 2,2’-N,N′-didecyl-dioxo-N,N′,N″,N″’-tetraazatetratriacontane-N″,N″’-diyl diacetic acid (H2E-4C10), has been investigated. Initial screening results demonstrated acceptable solubility (ca. 15 mM) of the diamide in 1,3-diisopropylbenzene (DiPB) and in a 93:7 v:v n-dodecane:n-octanol mixture (DOm) as non-polar diluents. Further investigations aiming at determining operational parameters associated with the befitted extractant systems were conducted at pH ranging from 2 to 4 in chloride and nitrate media. A pH-dependent performance of the proposed systems revealed loading capacity peaking at pH = 3 with the respective values of 1.7 and 2.0 g L−1 in nitrate and chloride media. The extraction efficiency, the distribution coefficients, and the separation factor (E%,D and SF, respectively) were determined for an equimolar mixture of neodymium (Nd) and two other potential competitive lanthanides, namely dysprosium (Dy) and praseodymium (Pr). The best selectivity was observed in the chloride medium at pH = 4 yielding SFNd/Pr = 1.48 and SFNd/Dy = 2.03. Neodymium-to-extractant stoichiometry was evidenced in chloroform to be 1:1 H2E:Nd at pH = 2. Thermodynamic constants related to the considered extraction equilibrium have been determined by using the Van't Hoff relation and the slope analysis method. It appeared within the selected pH-range that the mechanism of the Nd3+ transfer was strongly influenced by the nature of the diluent. This was illustrated by the enthalpy-driven transfer when Nd3+ was extracted with the H2E-4C10-Dom system (aliphatic diluent) while the transfer became entropy-driven when the extraction was performed with the H2E-4C10-DiPB system (aromatic diluent). The complexation of Nd3+ involved mainly the participation of both the amide and carboxylic functional groups. The transfer of the cation to the organic phase might occur through the formation of the Nd(HE)A2 complex (where A is either a nitrate or a chloride anion), allowing for the lowest associated standard Gibbs free energy of transfer (−28 < ΔG° < −24 kJ mol−1) regardless of the aqueous feed.

Effect of surface corrosion on the zeta potential of copper in acidic solutions

The comprehensive investigation was conducted to analyze the corrosion behavior and surface potential of pure copper surfaces in various acidic solutions. We carried out Zeta potential measurement, electrochemical measurement and in situ Raman spectroscopy to investigate the corrosion process and surface potential of copper in acidic solutions with different pH. It was found that the variation in zeta potential with pH corresponds to the corrosion behavior of copper during this process. In 1mmol / L aqueous chloride media, when the pH is greater than 3.5, unalloyed copper is oxidized to monovalent copper. At this stage, as the pH decreases, the zeta potential gradually increases. When the pH reaches 3.5, the Zeta potential reaches the highest, and the rate of cuprous oxide formation reaches the maximum. When the pH continues decrease, unalloyed copper begins to be oxidized to divalent copper, and the zeta potential will also decrease, the surface charge state shifts to the positive direction. Furthermore, our experimental findings are complemented by Density Functional Theory (DFT) calculations.

Comparative study of MMO and BDD anodes for electrochemical degradation of diuron in methanol medium

Treating emerging pollutants at low concentrations presents significant challenges in terms of degradation efficiency. Anodic oxidation using active and non-active electrodes shows great potential for wastewater treatment. Thus, this study compared the efficiency of a commercial mixed metal oxide anode (MMO: Ti/Ti0.7Ru0.3O2) and a boron-doped diamond anode (BDD) for the electrochemical oxidation of diuron in methanol, in chloride and sulfate media. The MMO anode achieved diuron removal rates of 94.9% and 92.8% in chloride and sulfate media, respectively, with pseudo-first-order kinetic constants of 0.0177 and 0.0143 min−1. The BDD anode demonstrated slightly higher removal rates, achieving 96.2% in sulfate medium and 96.9% in chloride medium, with respective kinetic constants of 0.0193 min⁻1 and 0.0177 min⁻1. Increasing the current density enhanced diuron removal by up to 15% for both electrodes; however, excessively high current densities led to increased energy consumption due to side reactions. The present of water had antagonistic effects, resulting in removal rates of 91.1% for chloride media using the BDD anode; and 87.4% and 90.4% in sulfate media with MMO and BDD anodes, respectively. The MMO anode in chloride medium did not show significant difference in the degradation percentage, reaching 96% of diuron removals. The degradation mechanism was proposed based on the detection of various by-products. The primary reactions observed during the oxidation of diuron in methanol involved chlorine substitution in the aromatic ring and dealkylation. These processes generated several intermediates and by-products at low concentrations, ultimately leading to high diuron removal.

Crystallization test: A prognostic biomarker in oral potentially malignant disorders and oral cancer.

The aim of study is to evaluate the crystallization pattern seen in cupric chloride medium using haemolyzed blood of control, Oral potentially malignant disorders (OPMDs) and oral squamous cell carcinoma (OSCC) patients. Study comprise 90 patients including control, OPMDs and OSCC. To create a haemolysed blood, a drop of blood was obtained and distilled water was added. Crystallization test using 0.1 ml of haemolyzed blood and 20% of a 10 ml cupric chloride solution. During 24 to 28 hours, this solution was put in a BOD incubator. Crystallization pattern in control group is eccentric placed nucleus and peripheral radiating lines while in OPMDs and OSCC presence of transverse bar. Crystallization test showed 100% positivity in OSCC while 73.33% seen in control group. 90% sensitivity in OSCC and 76.67% sensitivity in OPMDs. OPMDs lesion convert from white to mixed red and white lesion and OSCC appear as non-healing ulcer or ulcero-proliferative growth increase in number of transverse bars. More number of transverse bars suggestive of high malignant potential.

Elaboration and investigation of formulated polymer composites as some potential anticorrosion coatings for brass surface in 3.5% NaCl solution: theoretical approaches

ABSTRACT Polymer composite derivatives [(TGEMM/MDA/0%, TGEMM/MDA/6%, TGP/MDA/0%, and TGP/MDA/6%)] were elaborated through using tetraglycidyl ether of methyl-α-D-mannopyranoside (TGEMM) and 2,3,4,5-tetraglycidyloxy pentanal (TGP) as matrices, methylene dianiline (MDA) as curing agent and glass system (1-x) (2Bi2O3 - B2O3) - x BaO (with x = 0% and 6%) as filler. Different composites prepared were investigated as some potential anticorrosive protection coatings for brass electrode in sodium chloride medium (3.5% NaCl). Polymer composite coatings were characterized using FTIR spectroscopy, SEM/EDS, EFM, PDP, and EIS techniques. The anticorrosive protection efficiencies increase with increasing charge incorporated in composites, in the following order: TGP/MDA/0% < TGEMM/MDA/0% < TGP/MDA/6% < TGEMM/MDA/6% and the later achieving a maximum of 90.67% (EFM), 95.45% (PDP), and 97.86% (EIS), respectively. SEM/EDS characterization suggests a smooth surface in the presence of composite derivatives, which is more significant in the presence of TGEMM/MDA/6%. DFT calculations and MD simulations confirm the data obtained by experimental study and offer insights into its structural properties.

Experimental study on surface optimization of dosage in magnetic coagulation process for enhancing primary treatment of urban sewage

This work aims to investigate the minimum dosage required to achieve optimal removal of carbon, nitrogen, and phosphorus in the Chemical Enhanced Primary Treatment (CEPT) process using magnetic coagulation technology. A response surface methodology was adopted to generate multiple regression models to optimize the dosages of three types of coagulation, i.e., polyaluminum chloride (PAC), polyacrylamide (PAM), and magnetic medium Fe3O4 particles (MP), based on the removal rates of chemical oxygen demand (COD), ammonia nitrogen (NH3-N), and total phosphorus (TP). The results showed that the regression models could predict results well with actual engineering results. Compared to the traditional coagulation process, the synergistic enhancement of PAC+PAM+MP in the CEPT process significantly improved the treatment effects. Based on the COD removal rates, PAC performed better than MP, followed by PAM; likewise, for the NH3-N and TP removal rates, PAC outperformed PAM, followed by MP. The optimized PAC, PAM, and MP dosages were 135.87, 1.51, and 108.36 mg/L, respectively, reaching 92.27 % COD, 71.98 % NH3-N, and 91.33 % TP removal rates with less than 5 % errors compared to the experimental verification results. These optimization models offer a practical and cost-saving reference for enhancing the primary treatment effect on carbon, nitrogen, and phosphorus removal using PAC+PAM+MP.

Separation and purification of heavy rare earth elements by a silica/polymer-based β-aminophosphonic acid resin from chloride media

High-purity heavy rare earths (HREs) are important for promoting the development of cutting-edge materials, but their efficient separation and purification still face significant challenges. Here, a silica/polymer-based β-aminophosphonic acid resin (HEHAEP/SiO2-P) was prepared by vacuum impregnation for the separation of HREs from chloride media. At pH = 2.0, the separation factors (SF) for Er/Ho, Tm/Er, Yb/Tm and Lu/Yb were 2.35, 3.62, 3.14 and 1.23, respectively, surpassing those of some other reported impregnating resins. The maximum adsorption capacity of HEHAEP/SiO2-P for Ho, Er, Tm, Yb and Lu were 33.5, 34.6, 37.0, 38.3 and 43.2 mg/g, respectively. The adsorption process was characterized as homogeneous monolayer chemisorption, driven by entropy in a spontaneous endothermic reaction. Complete desorption of the adsorbed HREs was achieved using 4.0 mol/L HNO3. Employing our strategy, as exemplified by Tm, high-purity Tm2O3 (99.997 %) was obtained by HEHAEP/SiO2-P resin in the column chromatography separation system. FT-IR and XPS analysis demonstrated that both P-OH and PO groups participated in the coordination reaction during the HREs adsorption.

Iron(III) and neodymium co-extraction mechanism with TODGA from chloride medium

In the context of NdFeB magnets recycling, solvent extraction of lanthanides using diglycolamides is promising but their separation from iron(III) remains a challenge. Here, the extraction mechanisms of iron(III) and neodymium by TODGA (N,N,N′,N′-tetraoctyldiglycolamide) were examined in chloride medium. The choice of chloride media was driven by the efficiency of HCl in dissolving NdFeB magnets. Neodymium was chosen as a representative lanthanide to examine the co-extraction mechanism. For the extraction of iron(III), UV–visible and FT-IR spectra provide evidence for the extraction of FeCl4- with the participation of TODGA carbonyl groups. For the extraction with both elements, the solvent extraction study points out that there is co-extraction of neodymium and iron(III). Neodymium(III) extraction percentage increases from 6 to more than 97 % by adding iron(III). From spectroscopic studies (UV–visible, FT-IR) and thermodynamic modelling of extraction data, it is shown that three molecules of TODGA extract neodymium, as for neodymium-only extraction. They also reveal the presence of Fe(III) as FeCl4- anion in the outer sphere of [Nd(TODGA)3]3+. This brings to the conclusion that [Nd(TODGA)3](FeCl4)3 complex is formed in the organic phase. DFT (Density Functional Theory) calculations confirm that FeCl4- can replace Cl- in the outer sphere of [Nd(TODGA)3]3+, in a two-step reaction, with the initial formation of [Nd(TODGA)3]Cl3 followed by the binding of FeCl3 to the outer-sphere chloride ion. These results pave the way to the design of new diglycolamides that are selective towards iron(III) from chloride medium. The complete dissolution solution of NdFeB is represented by a highly acidic medium (a solution of 3 M HCl), whereas the leaching solution (partial dissolution of NdFeB) is represented by a weakly acidic medium (NaCl).

Defatted microalgae Haematococcus pluvialis: A sustainable source for gold recovery

The defatted microalgae Haematococcus pluvialis (HP), obtained from various production lots, were subjected to two different treatments: drying without chemical treatment (DH1, DH2, and DH3) and treatment with concentrated sulfuric acid (TH1, TH2, and TH3). These treated materials were employed as efficient and eco-friendly adsorbents to investigate the adsorption behavior of Au(III) in acidic chloride media. The treated adsorbents demonstrated exceptional performance, achieving 100 % adsorption of Au(III) across a broad range of hydrochloric acid (HCl) concentrations from 0.01 to 5.00 M, whereas the dry adsorbents exhibited up to 90 % adsorption only at low HCl concentrations. Both dry and treated adsorbents exhibited superior selectivity for Au(III) in the presence of a mixture of precious metal ions. The adsorption isotherms of Au(III) followed the Langmuir type of adsorption mechanism, and the maximum adsorption capacities for Au(III) were estimated as 1.57, 0.88, and 1.52 mol kg–1 for DH1, DH2, and DH3, and 6.17, 4.80, and 5.37 mol kg–1 for TH1, TH2, and TH3, respectively. The adsorbed Au(III) ions were reduced to the elemental state, as confirmed by X-ray diffraction patterns, scanning electron microscopy/energy-dispersive X-ray analyses, and digital micrographs of the adsorbents after Au(III) adsorption. Successful desorption of the adsorbed Au(III) was achieved using acidic thiourea solution.

Arsenic immobilization from high-As sulfide copper ores through high-pressure leaching with ferric and sodium chloride media

The processing of high-impurity ores has become increasingly common in recent years. Enargite (Cu3AsS4) is an important source of copper, but it is notorious for its high arsenic content, posing serious environmental concerns. This study explores the potential of a high-pressure leaching system for treating high-arsenic-containing copper ores. The leaching behavior of enargite was studied to elucidate the role of ferric sulfate and NaCl in enhancing the dissolution of enargite and the fixation of As in the residue. Under optimized leaching conditions of 160 °C, 1.0 MPa, 0.1 mol/L Fe2(SO4)3, and 0.34 mol/L NaCl, excellent copper extractions (97 %) and immobilization of arsenic (98 %) was achieved. The Fe/As ratio in the feed significantly influenced arsenic removal minerals, with lower ratios of less than 1 favoring scorodite precipitation, while higher ratios (Fe/As > 1) promoted arsenic removal through sorption and co-precipitation with natrojarosite. Sodium chloride addition enhanced natrojarosite precipitation, reducing the total dissolved iron in the leachate. Arsenic attenuation onto jarosite was found to be difficult to form in the absence of NaCl and was more effective with mixed minerals (enargite, chalcopyrite, and pyrite) as opposed to only enargite. A relationship was established between Fe and free acidity in the leachate when NaCl was used, with a correlation coefficient of 0.992. Additionally, a correlation coefficient of 0.921 was obtained between final Fe and As concentrations in the leachate suggesting that As tenors can be managed by controlling free acidity. Evaluation of the environmental stability of the leach residue using the TCLP test showed an As leachability of 5.84 mg/L.

Ultrafine Grain 316L Stainless Steel Manufactured by Ball Milling and Spark Plasma Sintering: Consequences on the Corrosion Resistance in Chloride Media

This paper reports experimental results concerning the corrosion of 316L austenitic stainless steels produced by ball milling and spark plasma sintering in NaCl electrolyte. Specimens with grain sizes ranging from 0.3 µm to 3 µm, without crystallographic texture, were obtained and compared with a cast that is 110 µm in grain size and an annealed reference. The potentiodynamic experiments showed that the reduction in grain size leads to a degradation of the electrochemical passivation behavior. This detrimental effect can be overcome by appropriate passivation in a HNO3 concentrated solution before consolidation. The Mott–Schottky measurements showed that the semiconducting properties of the passive layer do not vary significantly on the grain size, especially the donor density, which is responsible for the chemical passivation breakdown by chloride anions. The total electrical resistance of the layer, measured by impedance spectroscopy is always lower than the one of a cast and annealed 316L, but it slightly increases with a reduction in grain size in the ultrafine grain range. This is followed by a slight increase in the thickness of the oxide layer. The effect of chloride ions is very pronounced in terms of passivation breakdown if the powder is not passivated prior to sintering. This leads to the nucleation and growth of subsurface main pits and the formation of secondary satellite pits, especially for the smallest grain sizes. Passivation of the 316L powder before sintering has been found to be an effective way to prevent this phenomenon.

Obtention of Suitable Pregnant Leach Solution (PLS) for Copper Solvent Extraction Plants from Copper Concentrate Using Hydrogen Peroxide and Iodine in a Sulfuric Acid–Chloride Medium

Copper leaching presents an environmentally friendly alternative to traditional sulfide ore processing methods. This study investigates an efficient leaching process for copper concentrate, utilizing a solution of sulfuric acid (H2SO4) and potassium iodide (KI) in a chloride medium (NaCl), enhanced by hydrogen peroxide (H2O2) at room temperature. A significant aspect of this research was optimizing the KI concentration to minimize iodide sublimation into iodine gas (I2). Through the experimental design, the optimal dosages of reagents were determined, leading to maximized copper extraction of approximately 27% in 45 min of testing at room temperature. The results showed that it is possible to obtain a suitable pregnant leach solution (PLS) (i.e., in the range of 3 to 8 g/L of Cu) for treatment in available copper solvent extraction (SX) plants with a cost of less than 4.5 USD/t Cu, according to the economic analysis carried out. The results of this study determine the most effective operational conditions for leaching and ensure a suitable PLS for SX plants in a cost-effective and environmentally friendly manner. This approach could significantly contribute to more sustainable practices in the mining and processing of copper ores.

تثبيط التآكل للصلب المقوى في كلوريد الصوديوم بنسبة 3.5 % باستخدام عقار بنتوكسيفيلين منتهي الصلاحية: دراسة فقدان الكتلة

Corrosion is a major issue affecting the durability and performance of various metallic materials, leading to substantial economic losses and safety hazards. The corrosion of reinforced steel in sodium chloride environment poses a significant concern for various industrial applications. This study aims to investigate the corrosion inhibition properties of expired pentoxifylline drug on reinforced steel in a 3.5% NaCl solution. The mass loss method was utilized to quantify the corrosion rate and assess the efficiency of the expired pentoxifylline drug as a potential corrosion inhibitor. The results indicate that the corrosion rate of steel in the 3.5% NaCl solution decreased significantly in the presence of expired drug. Higher concentrations of expired drugs have shown a greater impact on corrosion inhibition. Investigation of the effects of temperature on corrosion inhibition efficacy. The inhibition efficiency increased with increasing concentrations of the inhibitor and decreased with increasing immersion time. The experimental data were tested according to the Langmuir adsorption isotherm, through which the equilibrium adsorption constant (Kads) was calculated and found to be 4.38 litres mol-1 as the maximum value when immersed for one day. The standard free energy of adsorption (∆G_ads^o) ranged from 45 to 30.5 kJ mol-1. Keywords: Reinforced steel, sodium chloride medium, inhibition, expired drugs, pentoxifylline

Exploring the viability of peracetic acid-mediated antibiotic degradation in wastewater through activation with electrogenerated HClO

Electrochemical advanced oxidation processes (EAOPs) face challenging conditions in chloride media, owing to the co-generation of undesirable Cl−disinfection byproducts (Cl−DBPs). Herein, the synergistic activation between in-situ electrogenerated HClO and peracetic acid (PAA)-based reactive species in actual wastewater is discussed. A metal-free graphene−modified graphite felt (graphene/GF) cathode is used for the first time to achieve the electrochemically-mediated activation of PAA. The PAA/Cl− system allowed a near−complete sulfamethoxazole (SMX) degradation (kobs =0.49 min−1) in only 5 min in a model solution, inducing 32.7− and 8.2−fold rise in kobs as compared to single PAA and Cl− systems, respectively. Such enhancement is attributed to the occurrence of 1O2 (25.5 μmol L−1 after 5 min of electrolysis) from the thermodynamically favored reaction between HClO and PAA-based reactive species. The antibiotic degradation in a complex water matrix was further considered. The SMX removal is slightly susceptible to the coexisting natural organic matter, with both the acute cytotoxicity (ACT) and the yield of 12 DBPs decreasing by 29.4 % and 37.3 %, respectively. According to calculations, HClO accumulation and organic Cl−addition reactions are thermodynamically unfavored. This study provides a scenario-oriented paradigm for PAA−based electrochemical treatment technology, being particularly appealing for treating wastewater rich in Cl− ion, which may derive in toxic Cl−DBPs.

Utilization of macroporous beads impregnated with Cyanex 572 for effective separation of Sr(II), Y(III), and Zr(IV) from chloride medium: batch and fixed-bed column study

This work focuses on using a new, inexpensive adsorbent, Amberlite XAD–4 resin impregnated with Cyanex 572 to extract and separate Zr(IV) from its parents Y(III) and Sr(II). The extraction performance was investigated using both batch and continuous flow techniques. The highest separation factor of Zr from Y and Sr was obtained at 0.05 mol L−1 HCl. Zr(IV), Y(III), and Sr(II) were found to have maximal monolayer capacities of 29.1, 9.3, and 6.1 mg g−1, respectively. Chromatography was utilized to effectively separate the relevant metals from their mixed solution in a single step, yielding high recovery values of approximately 99.0%.

Electrochemical behavior and theoretical studies of arylazo (1-naphthyl-2-cyanoacetamide) derivatives as new corrosion inhibitors for Inconel 800 in chloride solution

In this study, synthesize and insight the corrosion inhibition properties of two novel derivatives of 1-naphthyl-2-cyanoacetamide (NCDs) [2-cyano-2-((5,6-dimethyl-1H-benzo[d]imidazol-2-yl) diazenyl)-N (naphthalene-1-yl)acetamide] (NCD1) and [2-Cyano-N-(naphthalene-1-yl)-2-[(4,6-dimethyl-1H-pyrazolo [3, 4-b] pyridine-3-yl) hydrazono] acetamide] (NCD2). The characterization of the synthesized NCDs was confirmed through the utilization of Mass fragmentation analysis, 1H-NMR, and IR. The corrosion inhibition performance of NCDs as a novel and environmentally safe corrosion inhibitor has been investigated by electrochemical techniques, a chemical technique, and theoretical studies for its anti-corrosion behavior of Inconel 800 in chloride medium. In addition, the surface morphology and inhibitor adsorption on the Inconel 800 surface were confirmed utilizing SEM, EDX, FTIR, and AFM. The advantages of NCDs include their low toxicity, environmental friendliness, ease of preparation, low odor, contain (N, O, and π-Bonds), and the inhibition efficiency elevated with decreasing solution temperature as well as inhibitor dose increase, yielding increased efficiencies of 91.8% and 95.7% for NCD1 and NCD2, respectively, at the optimum concentration of 21 ×\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ imes$$\\end{document} 10–6 mol. L−1 and 298 K temperature. An analysis of Tafel plots reveals that NCDs adhere to a mixed and isothermal Langmuir adsorption mechanism. Density Functional Theory (DFT) and Monte Carlo (MC) simulation manifest the two compounds of NCDs can be adsorbed at the Fe (110) surface in a paralleled way, and can have a smaller energy gap (ΔE) value and exhibit higher efficiency. The experimental and theoretical findings confirm that the synthesized compounds obtained are capable of protecting the Inconel 800 from corrosion by creating an anti-corrosion coating on the surface.

Design, Manufacturing, Microstructure, and Surface Properties of Brazed Co-Based Composite Coatings Reinforced with Tungsten Carbide Particles

Brazing is a joining process that involves melting a filler metal and flowing it into the joint between two closely fitting parts. While brazing is primarily used for joining metals, it can also be adapted for certain coating deposition applications. The present study investigates the microstructure and corrosion behavior and sliding wear resistance of WC (Tungsten Carbide)-CoCr-Ni reinforced Co-based composite coatings deposited onto the surface of AISI 904L stainless steel using a vacuum brazing method. The primary objective of this experimental work was to evaluate the influence of WC-based particles added to the microstructure and the properties of the brazed Co composite coating. The focus was on enhancing the sliding wear resistance of the coatings while ensuring that their corrosion resistance in chloride media was not adversely affected. The morphology and microstructure of the composite coatings were investigated using scanning electron microscopy (SEM) and phase identification by X-ray diffraction (XRD). The SEM analysis revealed in the coating the presence of intermetallic compounds and carbides, which increase the hardness of the material. The sliding wear resistance was assessed using the pin-on-disk method, and the corrosion properties were determined using electrochemical measurements. The results obtained showed that as the WC particle ratio in the Co-based composite coating increased, the mechanical properties improved, the alloy became harder, and the tribological properties were improved. The evaluation of the electrochemical tests revealed no significant alterations of the manufactured composite in comparison with the Co-based alloys. In all cases, the corrosion behavior was better compared with that of the stainless-steel substrate.