Search Results (275)

Chloride ion penetration is one of the most aggressive threats to reinforced concrete, as it triggers the electrochemical corrosion of steel reinforcement, compromising structural integrity and durability. Chloride ingress occurs through the porous structure of concrete, making permeability control crucial for enhancing structural longevity. Fiber-reinforced concrete (FRC) is widely used to improve durability; however, the effects of different fiber types on chloride resistance remain unclear. This study examines the influence of glass and polypropylene fibers on concrete’s microstructure and chloride penetration resistance. Cylindrical specimens were prepared, including a reference mix without fibers and mixes with 0.25% and 0.50% fiber content by volume. Both fiber types were tested for chloride resistance. The accelerated non-steady-state migration method was employed to determine the resistance coefficients to chloride ion penetration, while X-ray macrofluorescence (MacroXRF) mapped the chlorine infiltration depth in the samples. Compressive strength decreased in all fiber-reinforced samples, with 0.50% glass fiber leading to a 56% reduction in strength. Nevertheless, the XRF results showed that a 0.25% fiber content significantly reduced chloride penetration, with polypropylene fibers outperforming glass fibers. These findings highlight the critical role of fiber type and volume in improving concrete durability, offering insights for designing long-lasting FRC structures in chloride-rich environments. Full article

Iopamidol (IPM), as a typical recalcitrant emerging pollutant and precursor of iodinated disinfection by-products (I-DBPs), is unsuccessfully removed by conventional wastewater treatment processes. This study comprehensively evaluated the ozone/peracetic acid (O₃/PAA) process for IPM degradation, focusing on degradation kinetics, environmental impacts, transformation products, ecotoxicity, disinfection byproducts (DBPs), and microbial inactivation. The O₃/PAA system synergistically activates PAA via O₃ to generate hydroxyl radicals (^•OH) and organic radicals (CH₃COO^• and CH₃CO(O)O^•), achieving an IPM degradation rate constant of 0.10 min⁻¹, which was significantly higher than individual O₃ or PAA treatments. The degradation efficiency of IPM in the O₃/PAA system exhibited a positive correlation with solution pH, achieving a maximum degradation rate constant of 0.23 min⁻¹ under alkaline conditions (pH 9.0). Furthermore, the process demonstrated strong resistance to interference from coexisting anions, maintaining robust IPM removal efficiency in the presence of common aqueous matrix constituents. Furthermore, quenching experiments revealed ^•OH dominated IPM degradation in O₃/PAA system, while the direct oxidation by O₃ and R-O^• played secondary roles. Additionally, based on transformation products (TPs) identification and ECOSAR predictions, the primary degradation pathways were elucidated and the potential ecotoxicity of TPs was systematically assessed. DBPs analysis after chlorination revealed that the O₃/PAA (2.5:3) system achieved the lowest total DBPs concentration (99.88 μg/L), representing a 71.5% reduction compared to PAA alone. Amongst, dichloroacetamide (DCAM) dominated the DBPs profile, comprising > 60% of total species. Furthermore, the O₃/PAA process achieved rapid 5–6 log reductions of E. coli. and S. aureus within 3 min. These results highlight the dual advantages of O₃/PAA in effective disinfection and byproduct control, supporting its application in sustainable wastewater treatment. Full article

In this study, a pH-responsive nanophotosensitizer (MT@Ce6) was rationally developed by strategic integration of MIL-101 (Fe)-NH₂ metal–organic framework with tannic acid (TA) and chlorin e6. This nanocomposite exhibits pH-responsive degradation in acidic microenvironments, facilitating Fe³⁺ release and subsequent reduction to Fe²⁺ that catalyzes Fenton reaction-mediated hydroxyl radical (•OH) generation. This cascade reaction shifts reactive oxygen species (ROS) predominance from transient singlet oxygen (¹O₂) to the long-range penetrative •OH, achieving robust biofilm disruption and over 90% eradication of methicillin-resistant Staphylococcus aureus (MRSA) under 660 nm irradiation. In vivo evaluations revealed accelerated wound healing with 95% wound closure within 7 days, while species-selective antibacterial studies demonstrated a 2.3-fold enhanced potency against Gram-positive bacteria due to their unique peptidoglycan-rich cell wall architecture. These findings collectively establish a microenvironment-adaptive nanoplatform for precision antimicrobial interventions, providing a translational strategy to address drug-resistant infections. Full article

Waterborne gastrointestinal infections remain a global health concern, with approximately 1.7 billion diarrhea-related illnesses annually attributable to protozoan parasites. These pathogens are transmitted through contaminated water and exhibit high resistance to chlorination, posing substantial challenges to effective water treatment. This study focused on the most prevalent intestinal parasites in the Los Ríos Region of Chile: Blastocystis sp., Giardia duodenalis, and Entamoeba coli. The objectives were to assess the prevalence of eukaryotic parasites in water samples—covering both drinking and recreational sources—to describe the circulating subtypes of Blastocystis sp. and to identify ecological factors associated with parasite presence. Water samples were analyzed using conventional PCR, next-generation sequencing (NGS) was employed for Blastocystis sp. subtype identification, and the environmental predictors were evaluated using a multivariable logistic regression model. A total of 132 water samples were analyzed, of which 15.2% were positive for Blastocystis sp. and 1.5% for E. coli, while no samples tested positive for G. duodenalis. We identified subtypes ST1–ST4 of Blastocystis sp., along with ST7, ST10, ST14, ST21, and ST23–ST26, the latter being reported for the first time in Chile. Ecological factors significantly associated with Blastocystis sp. presence included higher water temperature and greater rainfall at positive sites. Potable water was associated with significantly lower odds of Blastocystis sp. infection (aOR = 0.04, 95% CI: 0.00–0.87; p = 0.041), while precipitation increased infection odds by 3% per additional millimeter (aOR = 1.03, 95% CI: 1.00–1.06; p = 0.036). Greater distance to the nearest farmhouse was also significantly associated with reduced infection risk, suggesting that proximity to livestock environments may influence Blastocystis sp. transmission. These findings help explain the high prevalence of Blastocystis sp. observed in humans in the Los Ríos Region and highlight the pivotal role of ecological conditions in driving waterborne transmission. To our knowledge, this is the first environmental study in Chile to clearly demonstrate the association between human infection, environmental factors, and the transmission dynamics of Blastocystis sp. Full article

This review explores current knowledge on the environmental, oxidative, and genomic effects of sucralose (E955), an artificial sweetener widely used in food products, including those for children, and known to cross both the placental barrier and into breast milk. Although initially considered safe, research conducted over the past two decades has presented conflicting evidence regarding its long-term impact, particularly on ecosystems and biological systems. Structurally similar to chlorinated compounds such as perfluoralkyl substances (PFAS), sucralose is highly persistent in the environment, which complicates its degradation and removal, especially from aquatic systems. Several studies have reported behavioral, metabolic, and even genomic alterations in aquatic organisms exposed to sucralose, raising concerns about its broader ecological safety. In addition, its presence has been linked to shifts in microbiota composition in both environmental and human contexts. Reports of sucralose-induced oxidative stress further highlight the need for caution in its continued use, particularly in sensitive formulations. Given its widespread presence and resistance to degradation, further investigation into the environmental and biological safety of sucralose is urgently needed. Full article

The market value of litchi fruit is declining quickly due to its susceptibility to disease and rapid pericarp browning. Slightly acidic electrolyzed water (SAEW) treatment is recognized as a safe disinfection technology that not only preserves the quality of postharvest produce, but also enhances disease resistance. This study assessed the efficacy of SAEW in preserving litchi fruit and boosting its resistance to disease. Litchi fruit underwent treatment with SAEW at various available chlorine concentrations (ACC) (10, 25, 50, and 75 mg/L) and subsequently stored at 25 °C for a duration of six days. The results revealed that SAEW with an ACC of 25 mg/L markedly improved the postharvest quality of litchi fruits, reduced disease incidence, and enhanced the appearance of the pericarp and nutrient levels in the arils. Additionally, this treatment enhanced the levels of disease resistance-related compounds, including lignin, flavonoids, and total phenolics, in the pericarp of litchis during the later storage stages (p < 0.05). Furthermore, in the final three days of storage, there were also noticeable increases (p < 0.01) in the activities of pericarp disease resistance enzymes (DREs), such as phenylalanine ammonialyase, cinnamate-4-hydroxylase, 4-coumarate CoA ligase, cinnamyl alcohol dehydrogenase, peroxidase, polyphenol oxidase, chitinase, and β-1,3-glucanase. Based on these results, it was concluded that SAEW triggered DRE activities and increased the accumulation of disease resistance-related compounds by regulating the phenylpropane pathway to suppress disease development, and elevated the storage quality of harvested litchi fruit. Consequently, SAEW has proven to be an effective and safe method for enhancing the storability of litchi fruit. Full article

Photodynamic therapy (PDT) is a non-invasive therapeutic method with over a century of medical use, especially in dermatology, ophthalmology, dentistry, and, notably, cancer treatment. With an increasing number of clinical trials, there is growing demand for innovation in PDT. Despite being a promising treatment for cancer and bacterial infections, PDT faces limitations such as poor water solubility of many photosensitizers (PS), limited light penetration, off-target accumulation, and tumor hypoxia. This review focuses on chlorins—well-established macrocyclic PSs known for their strong activity and clinical relevance. We discuss how nanotechnology addresses PDT’s limitations and enhances therapeutic outcomes. Nanocarriers like lipid-based (liposomes, micelles), polymer-based (cellulose, chitosan, silk fibroin, polyethyleneimine, PLGA), and carbon-based ones (graphene oxide, quantum dots, MOFs), and nanospheres are promising platforms that improve chlorin performance and reduce side effects. This review also explores their use in Antimicrobial Photodynamic Therapy (aPDT) against multidrug-resistant bacteria and in oncology. Recent in vivo studies demonstrate encouraging results in preclinical models using nanocarrier-enhanced chlorins, though clinical application remains limited. Full article

Electrolysis desaturation has emerged as an innovative technique to mitigate liquefaction risk by reducing soil saturation in liquefiable foundations. This study evaluated the effectiveness of horizontal electrolysis on calcareous sandy foundations in marine environments by employing 35‰ NaCl solution as pore fluid under different current intensities (1A, 2A, and 4A). Experimental results demonstrated that hydrogen gas was generated at the cathode, while chlorine gas was produced at the anode, with peak gas retention rates of 100%, 90.83%, and 63.26% for 1A; 97.61%, 79.04%, and 60.94% for 2A; and 95.37%, 48.49%, and 42.81% for 4A over three electrolysis cycles. Three key findings emerged from our investigation: First, the resistivity of calcareous sand displayed a three-stage variation pattern, primarily governed by temperature and gas content evolution. Second, the temperature-corrected resistivity model provided reliable saturation data, revealing that electrode-adjacent soil layers exhibited significantly greater saturation reduction compared to intermediate layers. The average saturation variation during a single electrolysis cycle reached 3.2%, 2.6%, and 4.4% for 1A, 2A, and 4A, respectively, in the soil layers near the electrodes, compared to 2.1%, 1.7%, and 3.3% in the middle soil layers under the same current intensities. Third, upon stopping electrolysis, gas redistribution led to decreased saturation in upper soil layers, with lower current intensities more effective in retaining gases within the soil matrix. Based on these findings, an electrolytic influence coefficient for calcareous sand applicable to Archie’s formulation is proposed. This study enhances the understanding of the mechanism of electrolysis desaturation and provides a theoretical basis for the effectiveness of electrolysis desaturation on calcareous sand foundations. Full article

Cement-based materials used in China’s coastal and salt lake areas in the northwest are exposed to long-term chloride corrosion, which deteriorates the materials and substantially reduces the durability of the structures. This study investigates the chlorine ion erosion resistance in salt spray environments of cement-based materials made with iron ore tailings (IOTs) as an aggregate (namely, IOTCs). The compressive strength, mass loss, and relative dynamic elastic modulus (RDEM) macroscopic performance of IOTC undergoing different chloride diffusion times (0–180 d) were explored in detail. Chloride ion profiles at 0–180 d were analyzed via chemical titration, while X-ray computed tomography (CT) and scanning electron microscopy (SEM) were employed to characterize microstructural evolution. The results demonstrate that IOTC exhibited superior chloride resistance compared to conventional concrete (GC). While both materials showed early strength gain (<60 d) due to hydration and pore-filling effects, IOTC experienced only a 23.9% strength loss after long-term exposure (180 d) significantly less than the 37.2% reduction in GC. Chloride profiling revealed that IOTC had 43.5% lower free chloride ions (C_f) and 32% lower total chloride ions (C_t) at 1 mm depth after 180 d, alongside reduced chloride diffusion coefficients (D_a). The CT analysis revealed that IOTC exhibited a significantly denser and more uniformly distributed pore structure than GC, with a porosity of only 0.67% under chloride-free conditions. SEM confirmed IOTC’s more intact matrix and fewer microcracks. Full article

Fresh produce, such as peaches and apples, are agricultural commodities, making them susceptible to contamination by foodborne pathogens such as Listeria monocytogenes and Salmonella enterica. Traditional methods, such as chlorine washes, have limitations related to antimicrobial efficacy, prompting interest in alternative techniques, such as power ultrasound. This study evaluated the use of power ultrasound, alone and combined with organic acids (citric, lactic, and malic), to reduce pathogen populations on whole apples and peaches. Pathogen cocktails of L. monocytogenes and S. enterica were spot-inoculated on fruit surfaces at an initial population level of 8–9 log CFU/fruit. The fruits were then submerged in water or citric, malic, or lactic acid at concentrations of 1%, 2%, or 5% alone or with power ultrasound treatment at 40 kHz for 2, 5, or 10 min. Results revealed that treatment conditions on apples exhibited significantly greater pathogen reduction than on peaches, likely due to the smoother surface topology on apples compared to the rougher, trichome-covered peach surfaces. Between the two pathogens, L. monocytogenes exhibited significantly greater resistance to treatments, resulting in maximum reductions of approximately 4 log CFU/fruit. In contrast, treatments were more effective against S. enterica, as lactic acid alone reduced S. enterica populations by >6 log CFU/fruit. Malic acid was the second-most effective organic acid against S. enterica, leading to >4 log CFU/fruit reduction. Synergistic antimicrobial effects were observed when organic acids were used in combination with power ultrasound. For instance, an additional reduction of 2–3 log CFU/fruit was achieved for S. enterica compared to the use of organic acid treatments alone. These findings support the use of organic acid and power ultrasound in hurdle as an effective strategy to mitigate foodborne pathogen risks on whole fruits such as apples and peaches. Further research would be helpful to optimize and validate such hurdle treatments for inactivating a broader spectrum of microbial pathogens on diverse produce surfaces. Full article

The corrosion behaviour of lean duplex S32101 (1.4162—X2CrMnNiN21-5-1) stainless steel was assessed in various corrosive environments relevant to the pulp and paper industry. Electrochemical techniques, including open-circuit potential measurements and cyclic polarisation, were used to evaluate the corrosion resistance of S32101 stainless steel in various acidic, saline, and industrial liquors such as black, green, and white liquors, as well as dissolved chlorine dioxide bleaching solutions. To evaluate the extent of damage and corrosion mechanisms, post-exposure surface analysis was conducted using scanning electron microscopy (SEM). The results showed that S32101 experienced pitting corrosion in chloride-containing solutions, particularly in salt and acidified-salt environments. Corrosion rates increased with rising temperatures across all solutions. The highest corrosion rate of 3.17 mm/yr was observed in the highly alkaline white liquor at 50 °C, whilst chlorine dioxide induced the least aggressive effects at all temperatures. The suitability of S32101 stainless steel in handling pulp and paper liquors is shown in its corrosion resistance against the bleaching medium and low-temperature saline solutions, but it is not recommended for prolonged exposure to high alkaline liquors or chloride-rich solutions. Full article

Chlorine-based plasma is widely used in key etching applications. However, while etching the wafer materials, chlorine plasma can cause damage to the internal components of the etching chamber, which adversely affects the equipment’s lifespan. As a result, selecting appropriate coating materials for the chamber’s internal components is essential for mitigating corrosion. The etch resistance of these coatings directly impacts not only the quality of wafer production but also the operational safety and maintenance cycle of the etching equipment. In this study, three yttrium oxyfluoride coatings with different oxygen contents (3%, 6%, and 9%) were prepared using atmospheric plasma spraying technology. The etch resistance of these YOF coatings, as well as yttrium oxide coating, was systematically investigated under a Cl₂/O₂ plasma environment. Transmission electron microscopy analysis revealed that at the initial stage, Cl⁻ formed a protective layer on the surface of the YOF coatings, effectively slowing down further etching by Cl⁻. Among the samples, the YOF 6% coating exhibited the best etching resistance, which is primarily attributed to its higher capacity for Cl⁻ adsorption. Overall, YOF coatings demonstrated excellent resistance in chlorine-based plasma environments, with YOF 6% in particular showing great potential as an ideal protective material for etching chamber components. Full article

LaOCl-mediated ethane chlorination into 1,2-dichloroethane offers a promising pathway for low-temperature, large-scale ethane upgrading. However, under Cl₂-rich conditions, LaOCl undergoes detrimental chlorination into lanthanum chloride (LaCl₃), accompanied by extensive surface hydroxylation. Such severe structural evolution limits the practical application of La-based catalysts under industrially relevant conditions. In this study, an alumina-stabilized La catalyst was prepared via a coprecipitation method. We demonstrated that strong La-O-Al interactions effectively resist structural degradation of La species under reaction conditions, enabling the modified catalyst to maintain exceptional stability under high Cl₂ concentrations. At a C₂H₆/Cl₂ ratio of 4:9, the optimized catalyst achieves an ethane conversion of 61%, with 1,2-dichloroethane selectivity sustained above 74% for 12 h without noticeable deactivation. In contrast, the bulk LaOCl counterpart suffers from rapid over-chlorination, shifting product dominance to trichloroethane within 10 h. Advanced spectroscopy characterization reveals that selectivity loss in LaOCl originates from phase collapse into LaCl₃, whereas Al₂O₃ stabilization preserves the metastable LaOCl_x phase in a highly dispersed state, ensuring selective C–Cl bond formation. These results highlight the critical role of stabilizing metastable oxychloride phases through robust metal oxide interactions, establishing a design framework for rare-earth catalysts in high-concentration chlorine environments. Full article

The prevention of human infectious diseases associated with waterborne pathogens is reliant on the effective disinfection of water supplies by drinking water treatment plants and adequately maintained distribution networks. For decades, the chlorination of water has safeguarded public health, where chlorine is broadly applied in both water disinfection and food production facilities, including the dairy industry, from farm to fork. The identification of chlorine disinfection byproducts in water supplies and dairy food produce is of great concern, however, due to their cytotoxic, genotoxic, mutagenic, teratogenic, and potential endocrine-disrupting activity. The association between the trihalomethanes (THMs) and haloacetic acids (HAAs) and tumour formation is documented and has led to the implementation of maximum contaminant levels enforced by the European Union. Furthermore, chlorine resistance in bacterial species is associated with multidrug resistance in clinically relevant pathogens, where antibiotic- and biocidal-resistant genes are also environmental pollutants. Increasing the concentration of chlorine to surmount this resistance will ultimately lead to increasing concentrations of byproducts in both water and food products, exceeding the EU requirements. This article provides insight into chlorine DBPs as a toxicological public health risk and the relationship between chlorine resistance and antibiotic resistance in microbes relevant to dairy food production. Full article

This study investigates the development and performance of a novel GE-EP@OIM solid corrosion inhibitor for enhancing long-term corrosion protection in the oil-and-gas industry’s corrosive environment. The inhibitor was synthesized by incorporating organic imidazole molecules (OIMs) into a Gel-Epoxy (GE-EP) matrix, achieving an OIM-loading capacity of approximately 34.75% (generally reported capacity is up to 20%). The solid inhibitor was designed as a smart material, which exhibits temperature-responsive release behavior in a chlorine-corrosive environment. A combination of electrochemical measurements, weight loss testing, and scanning electron microscopy (SEM) was employed to assess the inhibitor’s performance. The results demonstrate that GE-EP@OIMs significantly improve corrosion resistance, particularly at elevated temperatures (50 °C), with the long-term protection effect serving as a key highlight, maintaining efficacy for up to 60 days, and it shows enhanced stability compared to conventional inhibitors. While the mechanical properties of GE-EP@OIMs are slightly diminished due to the incorporation of OIMs, the inhibitor still meets the necessary fluidity and performance criteria for medium- to long-term applications. This material shows considerable promise for mitigating corrosion in oilfield operations, especially for downhole tubing, and presents a cost-effective solution to the widespread corrosion challenges in the industry. Full article