Chloride Research Articles

Catalyst for the Generation of OH Radicals in Advanced Electrochemical Oxidation Processes: Present and Future Perspectives

Heterogeneous Advanced Oxidation Processes (H-AOPs) are considered a new process for removing emerging pollutants. In this case, the high reactivity of hydroxyl radicals is used to degrade persistent organic pollutants. This review explores the state-of-the-art catalyst for hydroxyl radical generation in AOPs. As a parasite reaction, chloride ions appear in alkaline conditions and compete with the active sites. The theoretical foundation of catalyst performance is explored, focusing on the fundamental principles that govern the efficiency and mechanism of hydroxyl or chloride radical production. The synthesis and electronic modification sections explore the modifications of catalysts. It discusses key methodologies for catalyst preparation, with a particular emphasis on electronic modification that enhances both activity and stability. Finally, laboratory and pilot applications highlight the effectiveness of novel or modified catalysts in different scenarios. These last findings provide insights into the future directions for research and application, aiming to draw attention to the gap between laboratory studies and real-world implementations.

Compressive Strength and Chloride Ion Penetration Resistance of GGBFS-Based Alkali-Activated Composites Containing Ferronickel Slag Aggregates

Various studies have reported the use of alkali-activated composites to enable sustainable development in the construction industry as these composites eliminate the need for cement. However, few studies have used ferronickel slag aggregates (FSAs) as an aggregate material for alkali-activated composites. Alkali-activated composites are environmentally friendly and sustainable construction materials that can reduce carbon dioxide emissions from cement production, which accounts for 7% of global carbon emissions. In the construction industry, various research was conducted to improve the performance of alkali-activated composites, such as changing the binder, alkali activator, or aggregate. However, research on the application of ferronickel slag aggregate as an aggregate in alkali-activated composites is still insufficient. In addition, the effect of ferronickel slag aggregate on the performance of alkali-activated composites when using calcium-based or sodium-based alkali activators has not been reported yet. Thus, this study prepared ground granulated blast-furnace slag-based alkali-activated composites with 0, 10, 20, and 30% FSA as natural fine aggregate substitutes. Then, the fluidity, micro-hydration heat, compressive strength properties, and resistance to chloride ion penetration of the alkali-activated composite were evaluated. The test results showed that the maximum temperature of the CF10, CF20, and CF30 samples with FSA was 35.4–36.4 °C, which is 3.8–6.7% higher than that of the CF00 sample. The 7 d compressive strength of the sample prepared with CaO was higher than that of the sample prepared with Na2SiO3. Nevertheless, the 28 d compressive strength of the NF20 sample with Na2SiO3 and 20% FSA was the highest, with a value of approximately 55.0 MPa. After 7 d, the total charge passing through the sample with Na2SiO3 was approximately 1.79–2.24 times higher than that of the sample with CaO. Moreover, the total charge decreased with increasing FSA content.

Oriented Growth of Highly Emissive Manganese Halide Microrods for Dual‐Mode Low‐Loss Optical Waveguides

Zero‐dimensional (0D) structured lead‐free metal halides have recently attracted widespread attention due to their high photoluminescence quantum yield (PLQY) and negligible self‐absorption, showing enormous potential as optical waveguides towards miniaturized photonic devices. However, due to the great difficulty in growth of rod‐like nano/micro‐sized morphologies, such applications have been less explored. Herein, a new‐type emissive organic‐inorganic manganese (II) halide crystal (TPS2MnCl4, TPS = C18H15S, triphenylsulfonium) in the form of microrods is synthesized via a facile chloride ion (Cl‐) induced oriented growth method. Due to a combination of attractive features such as a high PLQY of 86%, negligible self‐absorption and smooth crystal surface, TPS2MnCl4 microrods are well suited for use in optical waveguide with an ultra‐low optical loss coefficient of 1.20·10‐4 dB μm‐1, superior to that of most organic‐inorganic metal halide hybrids, organic materials, polymers and metal nanoclusters to the best of our knowledge. Importantly, TPS2MnCl4 microrods can further work as dual‐mode optical waveguides, combining active and passive light transmission functionalities in one single crystal. In addition, TPS2MnCl4 microrods also display remarkable performance in lighting and anti‐counterfeiting due to their distinct optical properties and commendable stability.

The Influence and Mechanism of Polyvinyl Alcohol Fiber on the Mechanical Properties and Durability of High-Performance Shotcrete

This study investigates the impact of polyvinyl alcohol (PVA) fibers on the mechanical properties and durability of high-performance shotcrete (HPS). Results demonstrate that PVA fibers have a dual impact on the performance of HPS. Positively, PVA fibers enhance the tensile strength and toughness of shotcrete due to their intrinsic high tensile strength and fiber-bridging effect, which significantly improves the material’s splitting tensile strength, deformation resistance, and toughness, and the splitting tensile strength and peak strain have been found to be increased by up to 30.77% and 31.51%, respectively. On the other hand, the random distribution and potential agglomeration of PVA fibers within the HPS matrix can lead to increased air-void formations. This phenomenon raises the volume content of large bubbles and increases the average bubble area and diameter, thereby elevating the pore volume fraction within the 500–1200 μm and >1200 μm ranges. Therefore, these microstructural changes reduce the compactness of the HPS matrix, resulting in a decrease in compressive strength and elastic modulus. The compressive strength exhibited a reduction ranging from 10.44% to 15.11%, while the elastic modulus showed a decrease of between 8.09% and 12.67%. Overall, the PVA-HPS mixtures with different mix proportions demonstrated excellent frost resistance, chloride ion penetration resistance, and carbonation resistance. The electrical charge passed ranged from 133 to 370 C, and the carbonation depth varied between 2.04 and 6.12 mm. Although the incorporation of PVA fibers reduced the permeability and carbonation resistance of shotcrete, it significantly mitigated the loss of tensile strength during freeze–thaw cycles. The findings offer insights into optimizing the use of PVA fibers in HPS applications, balancing enhancements in tensile properties with potential impacts on compressive performance.

Printing High‐Quality Formanidinum Lead Triiodide Films: Understanding the Critical Role of α‐Phase Nucleation Before Thermal Annealing

AbstractUpscaling the coating of formamidinium lead triiodide (FAPbI3) thin film is essential to realizing full printing and thereby roll‐to‐roll production of perovskite photovoltaics. However, thin‐film FAPbI3 processed from antisolvent‐free, printing methods suffer from undesirable degradation to the non‐photoactive phase, particularly in ambient processing conditions. Here, the most critical stage in thin‐film processing is identified as the gas‐quenching treatment of the as‐cast wet film. It is crucial to achieve both the nucleation of α‐phase nanocrystals and their sufficient growth at room temperature, which are indispensable for templating the growth of a highly crystalline and stable α‐FAPbI3 film during subsequent thermal annealing. The gas‐quenching‐treated film without these α‐phase nanocrystals can only be converted to meta‐stable α‐FAPbI3 by thermal annealing. By precisely identifying the spontaneous doping of cesium ion (Cs+) as a key factor in triggering α‐FAPbI3 nucleation and the role of chloride ion (Cl−) in enhancing nanocrystal growth, a generalized mechanism for additive engineering for the precursor ink is theorized. The identified mechanism translates to a power conversion efficiency of 19.36% for fully printed carbon‐electrode solar cells, 16.23% for carbon‐electrode minimodules, and excellent operational stability, showing the promising potential of this proposed fabrication route in the upscaling of perovskite photovoltaics.

Oriented Growth of Highly Emissive Manganese Halide Microrods for Dual-Mode Low-Loss Optical Waveguides.

Zero-dimensional (0D) structured lead-free metal halides have recently attracted widespread attention due to their high photoluminescence quantum yield (PLQY) and negligible self-absorption, showing enormous potential as optical waveguides towards miniaturized photonic devices. However, due to the great difficulty in growth of rod-like nano/micro-sized morphologies, such applications have been less explored. Herein, a new-type emissive organic-inorganic manganese (II) halide crystal (TPS2MnCl4, TPS = C18H15S, triphenylsulfonium) in the form of microrods is synthesized via a facile chloride ion (Cl-) induced oriented growth method. Due to a combination of attractive features such as a high PLQY of 86%, negligible self-absorption and smooth crystal surface, TPS2MnCl4 microrods are well suited for use in optical waveguide with an ultra-low optical loss coefficient of 1.20·10-4 dB μm-1, superior to that of most organic-inorganic metal halide hybrids, organic materials, polymers and metal nanoclusters to the best of our knowledge. Importantly, TPS2MnCl4 microrods can further work as dual-mode optical waveguides, combining active and passive light transmission functionalities in one single crystal. In addition, TPS2MnCl4 microrods also display remarkable performance in lighting and anti-counterfeiting due to their distinct optical properties and commendable stability.

Super Chloride Ionic Conductivity in CsSnCl3‐Based Perovskite Compound and Its Application for Solid‐State Chloride Batteries

A CsSnCl3‐based solid electrolyte in which 5% of Sn sites are occupied by Y ions, CsSn0.95Y0.05Cl3.05 (CSYC), is developed using a one‐step mechanical ball‐milling method. CSYC exhibits a stable cubic perovskite crystal structure and a high chloride ion conductivity of 4.9 mS cm−1. The relative density of a CSYC pellet following cold pressing without heat treatment is 97.5%. The high relative density and ionic conductivity are considered to originate from the high mechanical plasticity of the pellets, as evidenced by a low Young's modulus of 8.2 GPa. An all‐solid‐state chloride ion battery cell using CSYC as the electrolyte, BiCl3 as the active cathode material, and Sn as the anode is confirmed to operate at room temperature. The cell shows a large initial discharge capacity of 178 mAh g−1, ≈70% utilization, and good capacity retention with a reversible capacity of 100 mAh g−1 after 40 cycles. The mechanical plasticity of CSYC is considered to be a major contributor to its high ionic conductivity and good battery cycling performance.

Corrosion Evaluation and Mechanism Research of AISI 8630 Steel in Offshore Oil and Gas Environments

In this study, we optimized the traditional composition of AISI 8630 steel and evaluated its corrosion resistance through a series of tests. We conducted corrosion tests in a 3.5% NaCl solution and performed a 720 h fixed-load tensile test in accordance with the NACE TM-0177-2016 standard to assess sulfide stress corrosion cracking (SSCC). To analyze the corrosion products and the structure of the corrosion film, we employed X-ray diffraction and transmission electron microscopy. The corrosion rate, characteristics of the corrosion products, structure of the corrosion film, and corrosion resistance mechanism of the material were investigated. The results indicate that the optimized AISI 8630 material demonstrates excellent corrosion resistance. After 720 h of exposure, the primary corrosion products were identified as chromium oxide, copper sulfide, iron oxide, and iron–nickel sulfide. The corrosion film exhibited a three-layer structure: the innermost layer with a thickness of 200–300 nm contained higher concentrations of alloying elements and formed a dense, cohesive rust layer that hindered the diffusion of oxygen and chloride ions, thus enhancing corrosion resistance. The middle layer was thicker and less rich in alloying elements, while the outer layer, approximately 300–400 nm thick, was relatively loose.

Theoretical Study of the Halogen Concentration Effect on the 1,3-Butadiene Polymerization Catalyzed by the Neodymium-Based Ziegler–Natta System

In this work, an attempt is made to theoretically substantiate the experimentally known facts of the influence of halogen concentration on the catalytic properties of the neodymium-based Ziegler–Natta system. Based on the structural and thermochemical data obtained using modern methods of quantum chemistry, the process of the 1,3-butadiene cis-1,4-polymerization under the model active centers of the neodymium Ziegler–Natta catalysts with different contents of chloride ions was studied. Results are presented that explain the increase in the cis-stereospecificity and activity of the polymerization system with an increase in the content of the chloride ions in the neodymium catalytic system. Reasons were established for the decrease in the concentration of active centers relative to the introduced Nd(III) with an excess of chloride ions and the occurrence of the anti-syn isomerization as a source of the formation of the trans-1,4-structures in the cis-1,4-polybutadiene.

Experimental study on the influence of different curing methods on the performance of concrete

Curing concrete is an effective method to ensure concrete’s mechanical and durability performance. This article experimentally investigates the impact of various curing methods (air curing, sprinkler curing, geotextile curing, and composite geotextile curing) on the compressive strength of concrete at 7, 14, and 28 days, as well as the carbonation depth and chloride ion diffusion coefficient at 28, 56, and 90 days. The effects of different curing methods on concrete performance are compared. The experimental results demonstrate that sprinkler, geotextile, and composite geotextile curing at 7 and 14 days effectively enhance concrete’s mechanical and durability performance. Compared to air curing concrete at 28 days, sprinkler, geotextile, and composite geotextile curing reduced by 17.75 %, 25.11 %, and 31.51 %, respectively, but the average absolute deviation is reducing. From 28 to 90 days, air curing concrete’s chloride ion diffusion coefficient decreases by 8.5 %. For concrete specimens under sprinkler curing, geotextile curing, and composite geotextile curing, the chloride ion diffusion coefficient decreases by 20.4 %, 8.3 %, and 6.0 %, respectively. Beyond 28 days, the durability performance of concrete under composite geotextile curing, including carbonation depth and chloride ion diffusion coefficient, tends to stabilize. The optimal curing period of 28 days is determined based on comprehensive mechanical and durability performance. Composite geotextile curing retains moisture on the concrete surface, slows evaporation, reduces watering frequency and labour costs, and promotes long-term concrete performance development. Carbonation tests and durability performance, such as chloride ion diffusion coefficient, are more sensitive to concrete curing effects. Single indicators like mechanical or durability performance cannot comprehensively evaluate concrete’s long-term performance. Concrete quality should be comprehensively evaluated by considering strength, carbonation depth, chloride ion diffusion coefficient, and other indicators.

Efficient synthesis of cellulose acetate through one-step homogeneous acetylation of cotton cellulose in binary ionic liquids

Cellulose acetate (CA) is an important cellulose derivative with a wide range of applications. To adopt a more efficient and environmentally friendly method to synthesize cellulose acetate, a binary ionic liquid mixture of 1-butyl-3-methylimidazole chloride salt (BmimCl) and 1-butyl-3-methyldihydroimidazole phosphate (BmimH2PO4) was used. Compared to the conventional methods, this approach didn't require pre-activation of cellulose and the process of homogeneous acetylation proceeded without a catalyst. By simply adjusting the reaction conditions, cellulose acetate with a degree of substitution (DS) in the range of 0.83–3.0 was produced by one-step homogeneous acetylation without hydrolysis. Furthermore, the cellulose acetate film produced by solvent casting exhibited smooth surface characteristics, 95 % transparency, and 57.9 MPa tensile strength. Therefore, this study highlights the importance of using binary ionic liquid mixtures for facile synthesis of cellulose acetate. Due to their excellent transparency and mechanical properties, newly synthesized cellulose acetate films could replace commercial films.

Lubiprostone Improves Distal Segment-Specific Colonic Contractions through TRPC4 Activation Stimulated by EP3 Prostanoid Receptor

Background: Prokinetic agents are effective in increasing gastrointestinal (GI) contractility and alleviating constipation, often caused by slow intestinal motility. Lubiprostone (LUB), known for activating CLC-2 chloride channels, increases the chloride ion concentration in the GI tract, supporting water retention and stool movement. Despite its therapeutic efficacy, the exact mechanisms underlying its pharmacological action are poorly understood. Here, we investigated whether LUB activates the canonical transient receptor potential cation channel type 4 (TRPC4) through stimulation with E-type prostaglandin receptor (EP) type 3. Methods: Using isotonic tension recordings on mouse colon strips, we examined LUB-induced contractility in both proximal and distal colon segments. Quantitative real-time polymerase chain reaction (qRT-PCR) was conducted to determine mRNA levels of EP1-4 receptor subtypes in distal colonic muscular strips and isolated myocytes. The effects of a TRPC4 blocker and EP3 antagonist on LUB-stimulated contractions were also evaluated. Results: LUB showed significant contraction in the distal segment compared to the proximal segment. EP3 receptor mRNA levels were highly expressed in the distal colon tissue, which correlated with the observed enhanced contraction. Furthermore, LUB-induced spontaneous contractions in distal colon muscles were reduced by a TRPC4 blocker or EP3 antagonist, indicating that LUB-stimulated EP3 receptor activation may lead to TRPC4 activation and increased intracellular calcium in colonic smooth muscle. Conclusions: These findings suggest that LUB improves mass movement through indirect activation of the TRPC4 channel in the distal colon. The segment-specific action of prokinetic agents like LUB provides compelling evidence for a personalized approach to symptom management, supporting the defecation reflex.

Monte Carlo simulation of an ammonia adsorption refrigeration system based on calcium chloride impregnated nanoporous carbon.

We use Monte Carlo simulations to investigate the effect of incorporating calcium chloride salt into nanoporous carbon on the performance of an ammonia-carbon adsorption refrigeration system. Simulations of ideal carbon slit-pores with pore sizes of 1, 2, and 3nm, each containing calcium chloride with ion densities of 0.0, 0.25, and 0.5nm-3, were carried out at temperatures between 0 and 30 °C and ammonia pressures up to 15.0 bar. The results reveal that ideal 1nm pores are able to achieve a good refrigeration performance using waste heat below 100 °C to drive the process, but adding salt to these pores increases the waste heat temperature required beyond 100 °C. However, ideal 2nm pores require the addition of 0.25nm-3 salt to achieve a similar performance, while the 3nm pores were unable to achieve a satisfactory refrigeration performance. Considering that real nanoporous carbons usually feature a variety of specific adsorption sites and non-ideal geometries that should have a similar impact to adding salt, these results indicate that nanoporous carbons with pores in the range of 1-2nm are likely to hold the most promise for adsorption refrigeration applications and that the addition of salt may not always be helpful.

Cobalt Molybdenum Telluride as an Efficient Trifunctional Electrocatalyst for Seawater Splitting

A mixed-metal ternary chalcogenide, cobalt molybdenum telluride (CMT), has been identified as an efficient tri-functional electrocatalyst for seawater splitting, leading to enhanced oxygen evolution reaction (OER), hydrogen evolution reaction (HER), and oxygen reduction reaction (ORR). The CMT was synthesized by a single step hydrothermal technique. Detailed electrochemical studies of the CMT-modified electrodes showed that CMT has a promising performance for OER in the simulated seawater solutions, exhibiting a small overpotential of 385 mV at 20 mA cm−2, and superior catalyst durability for prolonged period of continuous oxygen evolution. Interestingly, while gas chromatography analysis confirmed the evolution of oxygen in an anodic chamber, it showed that there was no chlorine evolution from these electrodes in alkaline seawater, highlighting the novelty of this catalyst. CMT also displayed remarkable ORR activity in simulated seawater as indicated by its four-electron reduction pathway forming water as the dominant product. One of the primary challenges of seawater splitting is chlorine evolution from the oxidation of dissolved chloride salts. The CMT catalyst successfully and significantly lowers the water oxidation potential, thereby separating the chloride and water oxidation potentials by a larger margin. These results suggest that CMT can function as a highly active tri-functional electrocatalyst with significant stability, making it suitable for clean energy generation and environmental applications using seawater.

Chloride permeation resistance of sulphoaluminate cement-based composite characterized by both alternating current section and RCM methods

Sulphoaluminate cement (SAC) was widely used for rapid repair and strengthening of building structures due to its excellent quick hardening and high early strength behavior. This study developed a SAC-based engineering cement composites (ECC) with ultra-high molecular weight polyethylene (UHMWPE) and investigated its mechanical properties. Chloride ion permeability coefficient were evaluated by new alternating-current sectioning and rapid chloride migration (RCM). The mechanism of the SAC-ECC against chloride erosion were quantified using nitrogen isothermal adsorption. The results show that the fracture energy, tensile strength and strain of SAC-ECC samples are higher than that of normal ECC. The polyethylene (PE) fiber could significantly improve the flexural strength and toughness with PE fiber content of 0.75% by volume. The hydration products generated could react with chloride ion to make it chemically stabilized, leading to reduce the chloride ion diffusion coefficient significantly. Based on microscopic analysis (SEM), the pore structure in SAC-ECC composite improved remarkedly while the volume of harmful pore decreased evidently as well. SAC-ECC developed in this paper could be poetically applied to strengthening and repair of marine concrete structures.

Weak magnetic field for enhanced degradation of sulfamethoxazole by the CoFe2O4/PAA system: Insights into performance and mechanism

In this work, a novel approach coupling a heterogeneous weak magnetic field (WMF) with the CoFe2O4/peroxyacetic acid (PAA) system was employed to enhance the degradation of sulfamethoxazole (SMX). Under the optimized conditions of 50 mT WMF, 0.1 g/L CoFe2O4, 0.2 mM PAA, and initial pH 6.0, a complete degradation of 10 μM SMX was achieved in 25 min, exhibiting a high synergistic coefficient of 1.61. This result indicates a significant synergistic effect among WMF, CoFe2O4, and PAA in effectively degrading SMX. The introduction of WMF did not alter the pH application range of the CoFe2O4/PAA system. Furthermore, the degradation efficiency of SMX by the CoFe2O4/PAA/WMF system was significantly reduced in the presence of humic acid (HA) and bicarbonate ions (HCO3−), while chloride ions (Cl−) exhibited a minor inhibitory effect. Quenching experiments and electron paramagnetic resonance (EPR) analysis reveal that WMF did not alter the types of reactive oxygen species (ROS) generated in the CoFe2O4/PAA system. The degradation of SMX in the CoFe2O4/PAA/WMF system involved both radical (CH3C(O)O∙ and CH3C(O)OO∙) and non-radical (1O2) oxidation pathways, driven by the redox cycling between ≡Co2+/≡Co3+ and PAA, as well as the rapid adsorption and transformation of oxygen (O2) at oxygen vacancies (OV), respectively. The presence of WMF enhanced the utilization of PAA by CoFe2O4 by improving the convection and mass transport in the solution, facilitating the formation of superoxide anion (O2∙−) and supplemented lattice oxygen (O2−) through the directional migration of paramagnetic O2 towards the CoFe2O4 surface, thus significantly promoting ROS formation. Additionally, the degradation pathways of SMX in the CoFe2O4/PAA/WMF system were proposed based on density functional theory (DFT) calculations and the detected transformation products (TPs). The toxicity of SMX was effectively reduced, as verified by predictions from the Ecological Structure-Activity Relationship Model (ECOSAR) procedure. The excellent catalytic performance, reusability, and effective degradation of various organic pollutants demonstrated by the CoFe2O4/PAA/WMF system suggest its potential as a promising strategy for water treatment.

Stabilized/solidified chlorine saline soils with ground granulated blast furnace slag and calcium carbide residue

To optimize the use of chlorine saline soils commonly found in many coastal areas, ground granulated blast furnace slag (GGBS) and calcium carbide residue (CCR) were used in this study to stabilize/solidify these soils. This study aims at evaluating the suitability of GGBS-CCR as industrial by-products in improving the mechanical behaviors of chlorine saline soil in comparison with the use of Portland cement (PC) as a traditional binder. The optimal proportion of the binder was determined by the unconfined compressive strength, conductivity, and leaching characteristics. Moreover, the water stability coefficients, collapse coefficients and microscopic characteristics of the solidified soil were evaluated. The results reveal that when the ratio of GGBS to CCR in the binder is 4:1, the 28-day unconfined compressive strength reaches 4.53 MPa, and the leaching of chloride ions is reduced by 94.1 %. The excellent water stability and reduced collapsibility further indicate that GGBS-CCR is a preferable binder for solidifying saline soil compared to PC. Furthermore, microscopic analysis revealed that chloride ions in the saline soil were involved in the hydration reaction to form Friedel's salt.

Efficient removal of ammonia from aqueous solution using coal-based carbon membrane via electrochemical oxidation in the present of chloride ion

To tackle the escalating issue of ammonia nitrogen water pollution, developing efficient removal technologies holds paramount significance. In this work, an electrochemical membrane reactor (EMR) was constructed for the decontamination of ammonia nitrogen wastewater using the coal-based carbon membrane (CCM) as the flow-through anode. The removal efficiency and degradation mechanism of ammonia nitrogen by EMR during the treatment were investigated. It was found that, under applied voltage and in the presence of chloride ions, the CCM exhibited excellent chlorine evolution performance, and as a result, the EMR had excellent ammonia nitrogen removal efficiency. The removal of ammonia nitrogen by the flow-through EMR was following the pseudo-first-order kinetics. Analysis revealed that various operating parameters, including applied voltage, chloride ion concentration, flow rate, pH value, and initial ammonia concentration, all significantly influenced the ammonia nitrogen treatment performance of EMR. At optimal operation conditions (feed concentration of 30mg/L, applied voltage of 2.8V, NaCl concentration of 0.1mol/L and flow rate of 2ml/min), the EMR achieved a removal rate of 100% for ammonia nitrogen with a low energy consumption (EC) of 0.0380kW•h/g-NH4-N. The degradation mechanism analysis revealed that the primary means of ammonia removal relied on indirect oxidation mediated by OCl·, which was generated by the oxidation of Cl- on the surface of CCM within the solution under the influence of the electric field. Furthermore, the EMR demonstrated good applicability across various water matrices. In conclusion, the EMR holds considerable potential for the decontamination of ammonia nitrogen-containing wastewater.

The combined leaching of copper, gold and uranium in chloride solutions. I. Chalcopyrite

In a study (Part II) aimed at the simultaneous heap leaching of copper (predominantly chalcopyrite), gold and uranium from an ore, it was found that this could be achieved using chlorate as the oxidant in chloride solutions. As a result, a more detailed study has been made using electrochemical and batch leach tests on pure chalcopyrite electrodes under typical heap leach conditions.The use of chlorate at moderately low concentrations has shown that enhanced rates of dissolution of chalcopyrite can be maintained over periods up to 4 days at ambient temperatures in acidic chloride solutions. The rate of dissolution is enhanced at higher acid concentrations. The rate in the presence of chlorate does not appear to depend on the iron(III) (and presumably the copper(II)) concentration.The observed rates are significantly greater than those predicted for oxidative dissolution from the electrochemistry and the mixed potential model. An alternative non-oxidative mechanism has been revisited to account for this difference.A preliminary measurement has been made of the kinetics of the oxidation of hydrogen sufide and iron(III) by low concentrations of chlorine produced by reaction of chlorate with chloride ions. These reactions are rapid, and theory shows that they would support the proposed non-oxidative mechanism.

Analysis of deliquescent chloride salt by laser-induced breakdown spectroscopy with controlled uniform precipitation

BackgroundThe electrolytic efficiency in magnesium (Mg) production by molten salt electrolysis is mainly affected by the chloride content, which is determined by the metal content in the cooled molten salt. Laser-induced breakdown spectroscopy (LIBS) is a potential element detection method in cooled molten salt element detection. However, the cooled molten chloride salt is easily deliquescent, which greatly affects the LIBS detection results. ResultsTo solve the problem, a liquid-phase precipitation method based on the addition of a dispersant named as controlled uniform precipitation (CUP) method was proposed to pretreat the samples. Compared with the conventional powder compacting method and precipitation method, the CUP obtained the highest spectral stability and detection accuracy. The average relative standard deviation (ARSD) of Mg, Ca, and Na decreased from the 51.80%, 77.04%, and 44.01% to 6.77%, 6.27%, and 29.97%, the determination coefficient of the calibration curve (R2) increased from 0.044, 0.084, and -0.109 to 0.974, 0.954, and 0.802, and the average relative error (ARE) decreased from 58.49%, 52.46%, and 99.78% to 8.58%, 11.28%, and 29.38%, respectively, compared with the powder compacting method. Further investigation showed that the CUP method suppressed the sample deliquescence and the coffee ring effect, leading to the performance improvement of LIBS quantitative detection. SignificanceThe CUP provided an effective method of detecting metal elements for deliquescent samples and showed applied potential for other precipitable elements detection.