High Chloride Concentrations Research Articles

Accelerated corrosion effects on steel pipe pile materials in simulated Nhatrang seawater, Vietnam

Steel pipe piles are widely used in coastal infrastructure due to their high strength and durability. However, in tropical marine environments like Nha Trang, Vietnam, the high chloride content, temperature, and humidity significantly accelerate the corrosion process. Despite their extensive application, no published studies have specifically addressed the corrosion behavior of steel pipe piles in Vietnam's marine environment. This study investigated the accelerated corrosion effects on steel pipe pile materials in a simulated Nha Trang seawater environment, representing typical coastal conditions in Vietnam. Using an accelerated corrosion testing method, steel pipe pile material samples were exposed to controlled Nha Trang seawater conditions with varying salinity and environmental factors such as temperature and pH. The objective of this experiment was to analyze the corrosion rate and determine the corrosion mechanisms within a short period, simulating long-term effects typically seen in real seawater environments. The experiment revealed mass loss and pitting corrosion morphology on SKK490 samples, highlighting the degradation caused by high chloride content and other conditions in the Nha Trang simulated seawater environment. The results provide critical insights into the corrosion behavior specific to Nha Trang seawater environment of Vietnam, particularly regarding the reduction in cross-sectional area of the steel pile materials. These findings offer valuable guidance for coastal infrastructure projects, especially in the selection of appropriate materials and the development of effective corrosion prevention strategies for long-term use in seawater environments

Individual and Joint Effect of Oleic Acid Imidazoline and CeCl3 on Carbon Steel Corrosion in CO2-Saturated Brine Solution

In production and transportation systems of the oil industry, brine solutions contain high concentrations of chloride and dissolved CO2, which is a very corrosive medium to which carbon steel is exposed. Therefore, finding new effective and environmentally friendly corrosion inhibitors is of great importance. The effect of CeCl3 (in concentrations from 5 mg dm−3 to 20 mg dm−3) and oleic acid imidazoline (IOA) (in concentrations from 5 mg dm−3 to 20 mg dm−3) separately and their mixtures (in concentrations from 5 mg dm−3 to 15 mg dm−3 of CeCl3 and from 5 mg dm−3 to 20 mg dm−3 of IOA) as corrosion inhibitors of AISI 1018 carbon steel corrosion in simulated brine solution saturated with CO2 at 60 °C were examined by means of weight-loss testing, electrochemical measurements (polarization resistance, linear polarization with Tafel extrapolation, electrochemical impedance spectroscopy) and surface analyses (scanning electron microscopy with energy-dispersive X-ray spectroscopy analyses, Raman spectroscopy and X-ray diffraction). All test methods showed a higher efficiency of compounds′ mixtures (from 62.77% to 97.94%) and a higher degree of corrosion protection compared to the action of individual compounds (efficiency from 3.43% to 94.61% for IOA and from 57.58% to 96.27% for CeCl3). Imidazoline, a common corrosion inhibitor in CO2-saturated systems, most likely forms a surface film with voids via its adsorption on steel surface, while cerium carbonate tends to fill these voids by creating a more compact film. In this way, a denser and thicker surface film is formed.

Investigation of Chloride Salt Erosion on Asphalt Binders and Mixtures: Performance Evaluation and Correlation Analysis.

Asphalt pavement, widely utilized in transportation infrastructure due to its favourable properties, faces significant degradation from chloride salt erosion in coastal areas and winter deicing regions. In this study, two commonly used asphalt binders, 70# base asphalt and SBS (Styrene-Butadiene-Styrene)-modified asphalt, were utilized to study the chloride salt erosion effect on asphalt pavement by immersing materials in laboratory-prepared chloride salt solutions. The conventional properties and adhesion of asphalt were assessed using penetration, softening point, ductility, and pull-off tests, while Fourier transform infrared spectroscopy (FTIR) elucidated the erosion mechanism. The Marshall stability test, freeze-thaw splitting test, and Cantabro test were applied to study the effects of chloride exposure on the strength, water stability, and structural integrity of the asphalt mixture. Finally, the grey correlation analysis was employed to assess the impact of chloride salt erosion on the performance of asphalt binders and mixtures. The findings highlight that chloride salt erosion reduces penetration and ductility in both types of asphalt binders, raises the softening point, and weakens asphalt-aggregate adhesion, confirmed as a primarily physical effect by FTIR analysis. Asphalt mixtures showed decreased strength and water stability, intensifying these impacts at higher chloride concentrations and longer erosion duration. SBS-modified asphalt binders and mixtures exhibited greater resistance to chloride salt erosion, particularly in adhesion, as demonstrated by the Cantabro and pull-out tests. Grey relational analysis revealed that erosion duration is the most influential factor, with TSR and softening point emerging as the most responsive indicators of chloride-induced changes. These findings offer critical insights for practice, providing evidence-based guidance for designing and constructing asphalt pavements in environments with high chloride levels.

Chemical characterization of polymer and chloride content in waste plastic materials using pyrolysis - direct analysis in real time - high-resolution mass spectrometry.

The increasing global demand for plastic has raised the need for effective waste plastic management due to its long lifetime and resistance to environmental degradation. There is a need for rapid plastic identification to improve the mechanical waste plastic sorting process. This study presents a novel application of Temperature-Programmed Desorption-Direct Analysis in Real Time-High Resolution Mass Spectrometry (TPD-DART-HRMS) that enables rapid characterization of various plastics. This technique was applied on four commercially available reference polymers (polyethylene, polypropylene, polystyrene, polyvinyl chloride) as well as three "waste" plastic samples of mixed origin. These waste plastic samples were obtained as discards from various industrial processes with limited analytical characterization data. Through the application of CH2 Kendrick mass defect (KMD) grouping, characteristic trends in the mass spectra of each sample were identified, allowing for a simplified numerical comparison. This approach utilized a robust statistical approach using the Tanimoto coefficient, allowing for the quantitative measures of similarity between standards and unknown samples. The application of this mathematical evaluation methodology was used to identify plastic types and to distinguish structurally similar polymers. Additionally, we report that a chloride ion clustering effect with copper substrate can identify chlorinated polymer PVC (polyvinyl chloride) utilizing pyro-(-)DART-HRMS mode. PVC polymer is of particular interest in recycling due to its high chloride content, which can present technical challenges for some types of recycling. We found that chloride ion clusters are a good screening marker for the presence of chlorinated polymers in mixed waste plastic samples. This study can possibly help advance rapid and accurate analytical techniques for identifying the composition of waste plastics to advance the effectiveness of the waste plastic sorting process.

Balanced Electrolyte Solutions Versus 0.9% Saline for Kidney Transplantation: An Updated Systematic Review and Meta-analysis.

Perioperative intravenous fluids are administered to kidney transplant recipients to maintain hemodynamic stability and graft perfusion; however, the ideal fluid remains uncertain. Although 0.9% saline (saline) is commonly used, its high chloride content causes hyperchloremic metabolic acidosis and may increase the risks of delayed graft function (DGF) and hyperkalemia. Balanced electrolyte solutions (BES) have a more physiological chloride concentration and may reduce these risks. Previous meta-analyses found insufficient evidence to compare BES with saline for these outcomes; however, new studies have recently been published. In this updated review, we compared the effects of BES with saline on the risk of DGF and hyperkalemia in kidney transplantation. MEDLINE, Embase, and CENTRAL were searched for randomized controlled trials comparing BES with saline in kidney transplantation. The primary outcomes were DGF and hyperkalemia. Eligible studies were assessed for risk of bias and data were pooled for analysis. The Grading of Recommendations Assessment, Development, and Evaluation framework was used to assess the quality of evidence. Ten studies involving 1532 participants were included. The quality of evidence was high for deceased donor transplantation and very low for living donor transplantation. The relative risk (RR) of DGF associated with BES compared with saline was 0.83 (95% confidence interval [CI], 0.71-0.96; P = 0.01) in deceased donor transplantation. There was no difference in DGF in living donor transplantation (RR 0.79; 95% CI, 0.26-2.41; P = 0.68). There was no difference in hyperkalemia between groups (RR 0.87; 95% CI, 0.59-1.27; P = 0.46). Compared with saline, BES reduces the risk of DGF in deceased donor kidney transplantation without increasing hyperkalemia.

Effect of calcium chloride on thickening and rheological properties of a self-thickening acid

The crosslinked polymer acid solution relies on a crosslinking agent to form a high-viscosity gel under the condition of weak hydrochloric acid concentration (pH value of about 2–4), and it is difficult to form a high-viscosity gel at high hydrochloric acid concentration. In this work, calcium chloride was investigated as a promoter to enhance the thickening and rheological ability of a self-thickening agent, at high temperature and high concentrations of hydrogen chloride. The results demonstrated that 10 wt.% of calcium chloride can greatly increase the viscosity of a self-thickening acid in the range of high concentration acid (15–10wt.% of hydrogen chloride), which is conducive to the early diversion of the acid solution and better realizes the deep acidification of low permeability formation. Thus, this study provides a novel perspective for developing new self-diverting agents.

Management of groundwater resources in the Tolga region (south-east Algeria)

This study attempted to assess and map the quality of Tolga's groundwater in order to determine its suitability for human consumption and agricultural use. The results of analyses of the physicochemical parameters of the water samples were compared with WHO potability standards and standard agricultural water quality indices, namely sodium adsorption ratio SAR ,Soluble sodium percentage Na% , Magnesium risk MH , Kelly ratio KR and permeability index PI. According to the results analysed, most of the physicochemical parameters are above WHO tolerance limits and within the limits of empirical water quality indices for agricultural use. In our study, the graphical maps obtained by kriging are fitted with theoretical variogram models that best approximate the point cloud. The suitability of these models for our sample is verified by cross-validation results. The graphical representation shows high concentrations of conductivity, salinity, calcium, magnesium, sodium, bicarbonate and chloride, which are located in the Eastern part of the region, and increase progressively from northwest to east. These waters are highly charged with salts and have maximum conductivity values.

Midterm effects of irrigation with desalinated seawater on soil properties and constituents in a Mediterranean citrus orchard

Desalinated seawater (DSW) is the newest source of water for irrigated croplands, although its use could lead to soil degradation and crop phytotoxicity, due to its high concentrations of boron, sodium and chloride. However, the impacts of DSW on soil properties have not been thoroughly investigated, with more research needed to fully understand how DSW affects soil health. This study presents the effects of irrigating with DSW, mixed water (50 % desalinated seawater + 50 % fresh water) and DSW treated on-farm to reduce its boron concentration on soil properties and constituents, compared to fresh water. Soils were monitored at two depths (0–25 cm and 25–50 cm) every four months for six years, and soil physicochemical characteristics were analyzed. DSW presented low salinity (0.9 dS m–1), basic pH (8.4), high concentrations of Na, Cl, and B, and low concentrations of Ca and Mg. The results showed that soil nutrients, organic/inorganic carbon, pH, cation exchange capacity, and soil texture were not affected by the irrigation water used. However, after about three years of DSW application, soil accumulation of boron and sodium began to rise, with a clear tendency to increase over time, reaching concentrations of 2.3 mg kg−1 and 699 mg L−1, respectively, after six years. Conversely, the concentration of chlorides did not increase in soils irrigated with DSW, due to the high mobility of that element. Although no risk of salinization was observed with the use of DSW (mean value of 2.6 dS m−1), the risk of soil alkalinization increased, as the sodium absorption ratio rose from 4 to 6 and the exchangeable sodium percentage from 6.2 % to 10.2 %. The treatment involving on-farm B reduction provided the most suitable irrigation water, with the lowest concentrations in soil of available boron (1.4 mg kg−1), water-soluble chlorides (143 mg L−1) and sodium (129 mg L−1), and presented no risk of soil salinization (2.1 dS m−1) or alkalinization. Long-term DSW application could cause phytotoxicity and soil alkalinization. Therefore, strategies to mitigate those risks must be implemented, such as blending DSW with other water sources or on-farm DSW treatment to reduce its ionic load.

Correlation between surface wettability and fluid physics characteristics of lignite under compound solution regulation

The specific composition and ratio of the composite wetting agent will affect its dust reduction effect. Therefore, in order to study the effect of the composite wetting agent on the wettability and physical structure of lignite, the anionic surfactant sodium dodecyl sulfate was selected and mixed with different concentrations of sodium chloride to obtain different concentrations of the composite wetting agent. The correlation between the fluid physical properties of these composite wetting agents and the wetting of lignite surfaces was comprehensively explored by contact angle measurement, surface tension analysis, and low-temperature liquid nitrogen adsorption experiments, and the potential effects on pore structure were investigated. The results showed that as the sodium chloride concentration increased, the surface tension, contact angle, adhesion work, and surface free energy of the composite solution decreased, while the diffusion coefficient increased. There was a high linear correlation between the pore diameter of coal and the contact angle (R2 = 0.955), which revealed the close relationship between the permeability behavior of the fluid in the coal pores and the physical structure of the coal body. In addition, composite wetting agents with high sodium chloride concentrations exhibited a specific pore expansion effect, which helped optimize the coal's pore distribution and thus promoted effective coal wetting. This study not only deepens our understanding of the role of fluid physics principles in dust removal technology but also provides an important theoretical basis for selecting suitable composite wetting agents and their optimal ratios.

MIF Inhibition by ISO-1 Decreased Autophagic Activity in Primary Astrocytes During Cobalt Chloride-Induced Hypoxia.

Ischemic stroke is a leading contributor to death and disability worldwide, driving extensive research into pharmacological treatments beyond thrombolysis. Macrophage migration inhibitory factor (MIF), a cytokine, is implicated in several pathological conditions. In this study, we examined the effects of MIF on autophagy in astrocytes under the condition of chemical hypoxia. Primary astrocytes were treated with cobalt chloride, a well-known drug for inducing chemical hypoxia, followed by Western blot analyses to assess the HIF-1α, MIF, and LC3 protein levels along with a CCK assay. Additionally, cobalt chloride-treated astrocytes were co-treated with the MIF inhibitor ISO-1, and Western blot analyses were performed for MIF and LC3. Cell viability was evaluated using the CCK assay in astrocytes treated with cobalt chloride and ISO-1, with additional rapamycin treatment. Our results show that ISO-1 reduced LC3-II levels in astrocytes exposed to high concentrations of cobalt chloride (1000 μM) for 6 h. Moreover, rapamycin decreased cell viability in astrocytes treated with both 1000 μM cobalt chloride and ISO-1. Our data suggest that MIF plays a role in inducing autophagy in astrocytes under hypoxic conditions and is involved in the regulation of autophagic activity.

(Invited) Electrochemical Stripping for Ammonia Recovery: Mechanisms and Impacts of Chlorine Evolution

Electrochemical stripping is an attractive alternative to converting NH4 + to NH3(g) via the OH− produced by the hydrogen evolution reaction at the cathode. However, conventional electrochemical systems suffer from relatively low ammonia recovery (<80%) and need of external acid solution to absorb ammonia. To address the limitations, this work has developed a novel stacked system that uses anodic oxygen evolution reaction (OER) to in−situ produce acid and achieve chemical free ammonia recovery. To solve the issue of ammonia escape caused by constant current charging in conventional electrochemical systems, pulsed electric field (PEF) has been applied to regulate side reactions and interfacial mass transfer, weakening the sweeping effect of hydrogen gas produced by the cathodic hydrogen evolution reaction on ammonia gas. With an ammonia removal rate of 35.1 g−N m−2 h−1 and an electrical energy consumption of 28.9 kWh kg−N−1, our chemical−free system in PEF mode has achieved significantly higher ammonia recovery (>90%) from high-strength streams.With regard to a high concentration of chloride, high potentials during electrolysis may lead to the generation of strong active chlorine. The non−specific oxidation of ammonia by active chlorine results in lower ammonia recovery. This study therefore combined in−situ Raman spectroscopy to explore the effects of chloride ion concentration and pH on ammonia speciation and recovery. Under strong acidic conditions, active chlorine mainly escaped in the form of Cl2(g), thus having a negligible effect on ammonia recovery. The proposed system maintained good stability after 390 h continuous operation. While the effect of active chlorine on ammonia oxidation was negligible, the reaction of chlorine with dissolved organic matter (DOM) can form more toxic by-products. This work further realized the effective control of by-products through the integration with activated carbon adsorption process.Overall, the total cost to recover 1 kg of NH3–N using the electrochemical system from real waste stream is $15.9, which includes $11.1 for capital expenses (CapEx) and $4.8 for operating expenses (OpEx). This highlights the great potential for realizing high ammonia recovery in practical applications, and provides insights to innovations in treatment and resource recovery.

SNP alleviates ferric and salt stress in Phaseolus vulgaris seeds

Seed germination and early development are delicate events often influenced by various environmental factors. Among these factors, the accumulation of salts and heavy metals in the soil is noteworthy. This study aimed to observe the effect of priming with solutions of sodium nitroprusside, polyethylene glycol 6000, and potassium nitrate on the germination of Phaseolus vulgaris seeds exposed to toxic conditions of iron and sodium chloride. Seeds were germinated on plates placed in a growth chamber at a constant temperature of 25°C and a 12-hour photoperiod. The percentage of germination, germination speed, root and shoot lengths, catalase, peroxidase activities, and malondialdehyde content were evaluated. Exposure to high concentrations of sodium chloride and iron reduced germination percentage, germination speed, root and shoot lengths of treated plants. Only sodium nitroprusside treatment mitigated the effects of stressors. No increase in malondialdehyde content was observed in any treatment, suggesting no lipid peroxidation of membranes. However, all treatments showed increased catalase activity, possibly indicating oxidative stress and metabolic damage. Sodium nitroprusside stands out as a stress alleviator for sodium chloride and iron accumulation during the germination phase.

Anti-Amyloid Aggregation and Anti-Hyperglycemic Activities of Novel Ruthenium Uracil Schiff Base Compounds.

The formation and characterization of new diamagnetic ruthenium uracil mono-imine compounds: [(η6-p-cymene)RuII(L)Cl][BF4] (L=H2urpda=5-((pyridin-2-yl)methyleneamino)-6-aminouracil) for 1, urdpy=6-amino-1,3-dimethyl-5-((pyridin-2-ylmethylene)amino)uracil) for 2 or urqda=5-((quinolin-2-yl)methyleneamino)-6-aminouracil) for 3); cis-[Ru(bipy)2(urpy)](BF4)2 (4) (urpy=5-((pyridin-2-yl)methyleneamino)uracil) and cis-[Ru(bipy)2(dapd)] (5) (H2dadp=5,6-diaminouracil) are described. A ruthenium(IV) uracil Schiff base compound, trans-[Ru(urpda)(PPh3)Cl2] (6) was also formed. Various physicochemical techniques were utilized to characterize the novel ruthenium compounds. Similarly, the stabilities of 1-3 and 6 monitored in chloro-containing and the non-coordinating solvent, dichloromethane show that they are kinetically inert, whereas, in a high nucleophilic environment, the chloride co-ligands of these ruthenium complexes were rapidly substituted by DMSO. In contrast, the substitution of the labile co-ligands for these ruthenium complexes by DMSO molecules in a high chloride content was suppressed. Solution chemical reactivities of the different ruthenium complexes were rationalized by density functional theory computations. Furthermore, the binding affinities and strengths between BSA and the respective ruthenium complexes were monitored using fluorescence spectroscopy. In addition, the in vitro anti-diabetic activities of the novel metal complexes were assessed in selected skeletal muscle and liver cell lines.

Effects of Sodium-Glucose Co-Transporter 2 Inhibitors on Serum Chloride Concentrations in Patients with Heart Failure.

In the past few years, some reports have shown that serum chloride concentration is a more powerful prognostic predictor than serum sodium levels in heart failure (HF). Elevated Na/Cl ratio has shown to be independently associated with all-cause death in acute HF. We evaluated changes in serum chloride concentrations and Na/Cl ratio in correlation with various clinical factors during 12 months of follow-up in patients in whom SGLT2is were initiated as part of HF therapy. This was a prospective observational study conducted at University Hospital Dubrava and involving patients with HF. We included 241 participants between May 2021 and April 2023. All data were obtained before the introduction of SGLT2is, and the same parameters were obtained at 6 and 12 months of follow-up as well. The results show that higher chloride concentration at both 6 and 12 months is an independent predictor of lower NT-proBNP levels. The chloride concentrations did not differ significantly between these groups in the follow-up period. There were no statistically significant differences in the Na/Cl ratio at different timepoints. The presence of cardiovascular risk factors did not significantly affect the increase in chloride concentration. Our results suggest that hypochloremia could be a potentially modifiable risk factor, given the influence of SGLT2is on chloride concentration, but also an ominous sign of a poor outcome in patients with HF. We believe that the determination of chloride concentrations should become routine in the monitoring of patients with HF.

The MoS2/rGO embed in macro-porous PAN gel as a novel DGT binding phase for the rapid and accurate detection of trace Hg(II)

The development of binding gels with a fast uptake rate, high capacity, and good selectivity could be beneficial for trace Hg(II) detection based on the DGT technology. In this study, a novel PAN@MoS2/rGO-DGT was assembled by using the nanocomposite embedded in polyacrylonitrile membrane (PAN@MoS2/rGO) as the binding phase. The interior regular finger-like macropore of the gel provided a convenient channel for the rapid mass diffusion of Hg(II), and the abundant sulfur offered the paramount driving force for trapping Hg(II). These endowed the PAN@MoS2/rGO with an impressive reaction rate, capacity, and selectivity toward Hg(II) and featured the PAN@MoS2/rGO-DGT with excellent diffusion rate (D) and adaptability in the complex matrixes across a wide range of pH, ion strength, common cations. However, the uptake of Hg(II) was influenced by the high content of chloride, thus a calibrated model was established based on the chloride concentration to correct the accumulated mass and D. After that, the high accuracy of this method was confirmed through the good consistency between Hg(II) concentration assessed by DGT and in bulk solution when the DGT was deployed to the river water, seawater, and domestic wastewater at the static and dynamic Hg(II) concentration. Field trials in the prawn farming seawater and lake water also showed a negligible deviation of Hg(II) content from the DGT and the conventional method, acquiring the actual Hg(II) level as 1.07–3.69 ng/L. The findings highlighted the application potential of macropore PAN gel hybrid with nanocomposite as a promising binding phase for trace Hg(II) or other pollutant detection.

Groundwater remediation techniques around Kodungaiyur dump yard

Abstract The groundwater around the Kodungaiyur dump yard, in Tamil Nadu, India, is polluted due to the percolation of leachate from the dumpsite. This paper proposes three remedial techniques to make the groundwater drinkable for the people living near the Kodungaiyur trash yard. Twelve bore wells around the Kodungaiyur dumpsite provided water samples for which the physicochemical parameters were measured. Moderately high concentrations of Total Hardness (TH), Total Alkalinity (TA), Chloride, Sulphate, Nitrate, Sodium, and Total Dissolved Solids (TDS) are present in the groundwater around the dump yard. The Physicochemical parameters of the samples tend to deviate from the standards prescribed by WHO and BIS. Therefore, remedial measures such as solar distillation, Activated Charcoal, and the Phytoremediation process are suggested to reduce the contaminants in the groundwater. The activated charcoal removes the unpleasant color of the water completely and makes the water clear and transparent through filtration. The solar distillation process does not affect the pH value and is reduced by 4.5% in the phytoremediation technique. Similarly, the level of chlorides is reduced by 99% in solar distillation and by 56% in the phytoremediation technique. Total hardness is reduced by 89.88% in the solar still process and 56.65% in the phytoremediation technique. Sodium is reduced by 99.88% in solar still and 57.03% in the phytoremediation technique. The economical and eco-friendly nature of the suggested techniques makes it sustainable for future generations.

Understanding lipid oxidation in dried meat and cured dried meat: Insights from peroxide index analysis

The lipid oxidation process is one of the main food spoilage reactions, resulting in the appearance of unpleasant flavors and odors, known as rancidity. This study aimed to evaluate the lipid oxidation activity through the peroxide index, together with some chemical and biochemical constituents, of meat products with a high sodium content that underwent salting process and were sold to consumers. Samples of dried meat/charqui (CA: n = 22 and CB: n = 22) and jerked beef (JBA: n = 27 and JBB: n = 27) were analyzed. The peroxide index, rancidity test, formaldehyde test, sodium chloride, sodium, nitrite, proximate composition, and calories were analyzed. The main results demonstrated a high peroxide index and nitrite concentrations in jerked beef samples (JBA and JBB). The high concentrations of moisture and nitrite probably increased lipid oxidation in jerked beef samples, and lipid oxidation activity was inhibited by high concentrations of sodium chloride in dried meat samples.

Treatment of cosmetic wastewater containing N, N-dimethylformamide and high concentration of chloride salt by chemical precipitation and electrochemical method.

High-strength wastewater containing elevated levels of chloride salt and N, N-dimethylformamide (DMF) solvent was collected from manufacturing of sunscreen cream (for UVA/UVB protection) at a cosmetic factory. In evaporation process, precipitates, formed due to the high chloride content (around 160g/L), clog the pipeline, seriously reducing the treatment efficiency. This study aimed to develop a two-stage process integrating chemical precipitation and electrochemical oxidation to specifically remove the concentrated chloride salt and organic compounds (COD >100g/L). Chloride ions were initially recovered as insoluble Friedel's salt using calcium hydroxide (Ca(OH)2) and sodium aluminate (NaAlO2) as the precipitants. The [Cl]/[Ca]/[Al] ratio and solution pH were optimized to obtain a pure crystallized phase of Ca2AlCl(OH)6•2H2O. Afterwards, the organic compound were treated by a Fered-Fenton with the addition of H2O2 and FeSO4 to degrade the remaining COD. The cost and energy consumption of this integrated processes were evaluated, compared to the conventional evaporation method.

Corrosion study of cola soft drink cans

The study of corrosion in aluminium packaging is fundamental to ensuring the quality and safety of the product. The varnish layer present on metal packaging aims to minimize any interaction between the food or drink and the metal, as well as minimizing the corrosion process. The acidic nature of soft drinks, as well as the ions present in solution, such as phosphates, benzoates or chlorides, play a strong role in the oxidative process of aluminum. This study evaluated the corrosion of the body of aluminum cola cans. The beverage was first characterized and the results obtained were: pH =2.5; 7.5 oBrix; chloride concentration of 0.17g/L, acidity 0.17 %m/m; density 1.04 g/mL and concentration of reducing sugars was 11.3 %m/m. The corrosion of aluminum in model solutions with different concentrations of citric acid and NaCl was studied via linear polarization for samples with and without varnish. The statistical analysis carried out, via factorial design 23 with a triplicate at the center point, showed that the corrosion rate (CR) of the sample with varnish was significantly influenced by temperatures above 45 oC in the range of chlorides studied. On the other hand, the CR of the sample without varnish was strongly influenced by the combination of high temperatures and high chloride concentrations. Removing the varnish resulted in a higher activation energy (AE = 67.48 kJ/mol) when removed with acetone and then polished with sandpaper compared to the sample with varnish (AE = 88.92 kJ/mol). From a kinetic point of view, this showed the protective effect of this layer and its effectiveness against corrosion. The ΔHo and ΔGo activation parameters of the process were positive, showing that corrosion is an endothermic process with increased disorder when the varnish is removed, respectively. It is therefore important to buy the product with the packaging in good condition to guarantee the integrity of the protective layer and its quality, since oxidation of the aluminum can lead to products that compromise the quality of the food or drink.

Surface modification of fibres with silane for enhancing the durability of FRP composites as reinforcement for seawater sea sand concrete (SWSSC): A review

This review discusses the necessity of surface modification to effectively use fibre-reinforced polymers (FRPs) as reinforcements for seawater and sea sand concrete (SWSSC). FRPs can be a viable reinforcement material for SWSSC as an alternative to the traditional carbon steel reinforcement that will suffer unacceptably high rates of corrosion due to the very high chloride content of the SWSSC environment. FRPs exhibit mechanical properties similar to steels but suffer insignificant degradation/corrosion due to chloride. However, the fibres in certain FRPs (such as basalt FRPs and glass FRPs) suffer degradation due to attack by the alkaline environment of concrete, causing degradation in fibre-matrix interfacial strength and loss of FRPs’s overall mechanical strength and durability. Therefore, fibres used in such FRPs require suitable surface modification to ameliorate their degradation, enabling their practical use as reinforcements of SWSSC. While carbon fibre-reinforced polymers (CFRPs) demonstrate superior resistance to alkali-induced degradation, their widespread use in large-scale civil engineering is hindered by high costs. In this review, more economic alternatives, i.e., basalt fibre-reinforced polymers (BFRPs) and glass fibre-reinforced polymers (GFRPs) are critically reviewed. To enhance the durability of FRPs and mitigate alkali-induced degradation of the basalt/glass fibres, suitable surface modifications are necessary to safeguard the mechanical properties of FRPs. Underpinned by a comprehensive discussion on the necessity of surface modification of fibres for the use of FRPs in SWSSC environment, this review focuses on the potential of advanced approaches for surface modifications of the fibres, i.e., coatings of silanes, and silanes impregnated with graphene nanoplatelets (GNPs), graphene oxide (GO) and its functionalised derivatives or metal oxides (such as SiO2, ZrO2, Al2O3, TiO2 and CeO2). This review critically discusses the opportunities for suitable surface modification of basalt and glass fibres for enabling the durable use of FRPs as reinforcements for sweater sea sand concrete.