Search Results (151)

Water supply and sewage drainage pipes have a critical role to play in the provision of clean water and sanitation, and pipe material selection influences infrastructure life, water quality, and microbial communities. Zinc-containing compounds are highly valued due to their mechanical properties, anticorrosion behavior, and antimicrobial properties. However, the effect of zinc salts, such as zinc sulfate heptahydrate and zinc chloride, on biofilm-forming bacteria, including Escherichia coli and Enterococcus faecalis, is not well established. This study investigates the antibacterial properties of these zinc salts under simulated pipeline conditions using minimum inhibitory concentration assays, biofilm production assays, and antibiotic sensitivity tests. Findings indicate that zinc chloride is more antimicrobial due to its higher solubility and bioavailability of Zn²⁺ ions. At higher concentrations, zinc salts inhibit the development of a biofilm, whereas sub-inhibitory concentrations enhance the growth of biofilm, suggesting a stress response in bacteria. zinc chloride also enhances antibiotic efficacy against E. coli but induces resistance in E. faecalis. These findings highlight the dual role of zinc salts in preventing biofilm formation and modulating antimicrobial resistance, necessitating further research to optimize material selection for water distribution networks and mitigate biofilm-associated risks in pipeline systems. Full article

This work represents the first use of a phosphonium salt-functionalized β-Cyclodextrin polymer (β-CDP) as a highly selective sensing membrane for monitoring the safety of drinking water against perchlorate ions (ClO₄⁻) using electrochemical impedance spectroscopy (EIS). Structural confirmation via ¹H NMR, ¹³C NMR, ³¹P NMR, and FT-IR spectroscopies combined with AFM and contact angle measurements demonstrate how the enhanced solubility of modified cyclodextrin improves thin film quality. The innovation lies in the synergistic combination of two detection mechanisms: the “Host-Guest” inclusion in the cyclodextrin cavity and anionic exchange between the bromide ions of the phosphonium groups and perchlorate anions. Under optimized functionalization conditions, EIS reveals high sensitivity and selectivity, achieving a record-low detection limit (LOD) of ~10⁻¹² M and a wide linear range of detection (10⁻¹¹ M–10⁻⁴ M). Sensing mechanisms at the functionalized transducer interfaces are examined through numerical fitting of Cole-Cole impedance spectra via a single relaxation equivalent circuit. Real water sample analysis confirms the sensor’s practical applicability, with recoveries between 96.9% and 109.8% and RSDs of 2.4–4.8%. Finally, a comparative study with reported membrane sensors shows that β-CDP offers superior performance, wider range, higher sensitivity, lower LOD, and simpler synthesis. Full article

In the wake of global energy transition and the “dual-carbon” goal, the rapid growth of electric vehicles has posed challenges for large-scale lithium-ion battery decommissioning. Retired batteries exhibit dual attributes of strategic resources (cobalt/lithium concentrations several times higher than natural ores) and environmental risks (heavy metal pollution, electrolyte toxicity). This paper systematically reviews pyrometallurgical and hydrometallurgical recovery technologies, identifying bottlenecks: high energy/lithium loss in pyrometallurgy, and corrosion/cost/solvent regeneration issues in hydrometallurgy. To address these, an integrated recycling process is proposed: low-temperature physical separation (liquid nitrogen embrittlement grinding + froth flotation) for cathode–anode separation, mild roasting to convert lithium into water-soluble compounds for efficient metal oxide separation, stepwise alkaline precipitation for high-purity lithium salts, and co-precipitation synthesis of spherical hydroxide precursors followed by segmented sintering to regenerate LiNi_1/3Co_1/3Mn_1/3O₂ cathodes with morphology/electrochemical performance comparable to virgin materials. This low-temperature, precision-controlled methodology effectively addresses the energy-intensive, pollutive, and inefficient limitations inherent in conventional recycling processes. By offering an engineered solution for sustainable large-scale recycling and high-value regeneration of spent ternary lithium ion batteries (LIBs), this approach proves pivotal in advancing circular economy development within the renewable energy sector. Full article

Antibiotic resistance is a problem repeatedly reported by health authorities. Metalloantibiotics, i.e., biologically active compounds containing one or more metal ions, can be an important resource in the fight against bacteria and fungi. Here, we report the results obtained with a panel of copper(II), nickel(II) and zinc(II) complexes with thiosemicarbazone, semicarbazone and acylhydrazone ligands on Staphylococcus aureus, Escherichia coli and Candida albicans, taken as model systems of human pathogens. To increase the solubility in water, the sulfonic group was introduced on some of the ligands, isolating them as sodium salts (NaH₂L4-NaH₂L7). Complexes 1–14 were isolated, fully characterized and the X-ray structures of 11, 12 and 13 were obtained. While all the ligands have no antimicrobial activity, the copper(II) complexes 1 and 4 and the nickel(II) complex 2, obtained from thiosemicarbazone ligands, showed good activity, in particular against S. aureus; these complexes were investigated in depth, calculating their respective IC₅₀ values (4.2 μM, 3.5 μM and 61.8 μM, respectively). It should be noted that nickel(II) complex 2 does not show hemolytic activity and has a favorable SI value. While all the copper(II) complexes completely degraded the plasmid DNA in presence of H₂O₂, nickel(II) complex 2 cleaved the plasmid DNA leading to the formation of the relaxed nicked conformation, thus suggesting a different mechanism of action. Full article

Despite their inherently lower energy density than lithium-ion batteries (LIBs), aqueous zinc metal batteries (AZMBs) have recently attracted interest as rechargeable energy storage devices due to their low cost and high operational and environmental safety. They are composed of metallic zinc as the anode, an aqueous zinc salt electrolyte and a cathode capable of (de)intercalating Zn²⁺ ions upon its (oxidation) reduction reaction. In this work, we studied a hybrid AZMB in which a dual-ion electrolyte containing both Zn²⁺ and Li⁺ ions was used in conjunction with a Li⁺ ion intercalation cathode, i.e., LiFePO₄ (LFP), one of the most common, reliable, and cheap cathodes for LIBs. In this study, we present evidence that, thanks to its insolubility in water, ethyl cellulose (EC) can be effectively utilized as a binder for cathode membranes in AZMBs. Furthermore, its solubility in alcohol provides a significant advantage in avoiding the use of toxic solvents, contributing to a safer and more environmentally friendly approach to the formulation process. Full article

Soil salinity is a major constraint on crop cultivation, affecting millions of hectares of land and increasing drastically worldwide. Identifying sources of tolerance within the crops and their wild relatives is imperative. Recently, Solanum dasyphyllum L. has been identified as source of tolerance to drought for eggplant (S. melongena L.). In this article, the potential use of S. dasyphyllum as a source of tolerance to salinity is investigated through the characterization of young plants’ performance under three salt stress treatments, well water (control), as well as 200 mM and 400 mM NaCl. Biometric parameters such as leaf and radicular biomass, plant height, root length, and biochemical parameters—such as photosynthetic pigments, main ions accumulation, proline, total soluble sugars, malondialdehyde, total phenolics, flavonoids, and antioxidant enzymes’ activity—were quantified. The results showed a certain reduction in leaf and stem plant growth up to 60% in response to extreme salinity, while root biomass was maintained under mid-salt stress. Salt stress caused toxic ions to accumulate in plant organs, up to 1600 mmol g⁻¹ dry weight Na⁺ and a 2250 mmol g⁻¹ dry weight Cl⁻ in leaves under extreme salinity exposure. However, S. dasyphyllum maintained K⁺ levels at around 450 mmol g⁻¹ in leaves and roots and 750 mmol g⁻¹ in stems, indicating a mechanism related to ion transport to cope with ion toxicity. The biochemical response indicated osmotic adjustments and antioxidant activity without the need of activating antioxidant enzymes. S. dasyphyllum has proved to be a valuable genetic tool for new eggplant breeding programs regarding salt stress, with somewhat improved performance regarding biometric parameters and ion transport. Full article

It is of great significance to develop carbon quantum dots (CQDs) using green carbon sources, which are cheap, non-toxic and harmless, and further expand their application scopes, e.g., fluorescence sensors, blue light screening. In this study, we have prepared Peperomia tetraphylla-based carbon quantum dots (PT-CQDs) with strong water solubility, good salt resistance, specific quenching reactions and excellent optical properties via a simple one-step hydrothermal method. In one application, PT-CQDs are utilized as a fluorescence sensor due to their high selectivity and sensitivity to ferric ions (Fe³⁺). The limit of detection (LOD) was 2.7 μmol·L⁻¹. On the other hand, PT-CQDs/polyvinyl alcohol (PVA) films with excellent ultraviolet- (UV) and high-energy blue light (HEBL)-blocking properties were obtained. The obtained films exhibited a high blue light weight blocking rate of 100% in UV and 80% in HEBL. The concentrations of the composites could also be controlled to achieve the desired light-blocking rate. In addition, the composites were able to absorb blue light and convert it to other forms of light. These properties suggest their potential applications in the development of advanced blue light screening and fluorescence sensors. Full article

The gelation process and hydrogel properties of calcium salt-induced alginate hydrogels are influenced by anion-specific effects. In this study, we investigated the effects of CaSO₄, CaI₂, and Ca(C₅H₉O₃)₂ [calcium β-hydroxy-β-methylbutyrate, CaHMB] on the gelation behavior of alginate hydrogels, using various mannuronic/guluronic acid (M/G) ratios to elucidate the underlying mechanisms of anion-specific effects. Here, at a high M/G ratio (2:1), the gelation time of CaSO₄, as a low-solubility calcium source, delayed the formation of the calcium alginate hydrogel. The gelation time was 1.8 times that of the high-solubility calcium source CaHMB. Strongly hydrated ions (such as SO₄²⁻ and C₅H₉O₃⁻) caused the removal of water molecules from polysaccharide chains, resulting in the formation of small pores on the pore wall. Moreover, weakly hydrated chaotropic anions (I⁻) promoted the binding of alginate polysaccharide chains and water molecules, resulting in the slower thermal decomposition of water inside the gel. However, when the M/G ratio was reduced to 1:1 or 1:2, the influence of the three calcium salts on the water and thermodynamic properties of the hydrogels decreased, indicating that the anion-specific effect weakened. This study highlights the importance of anion-specific effects on the properties of alginate hydrogels and provides insights into the utilization of these effects to fabricate functional hydrogels with variable properties. Full article

Different films were synthesized from starch or polysaccharides extracted from distillers dried grains with soluble (DDGS) in combination with different percentages of linear polyethyleneimine (PEI) hydrochloride polymer to assess the mechanical and antimicrobial properties of the resulting composites. Moreover, a simple method for the extraction of the polysaccharide content from DDGS is reported. The materials obtained were characterized by ATR-FTIR, NMR, and XPS spectroscopy, swelling capacity, and by organic elemental analysis. In particular, the stability of the film prepared with only DDGS in copper ion solutions was improved by the incorporation of PEI. ¹³C HRMAS NMR studies evidenced the incorporation of the PEI polymer in the new films. Moreover, the release of PEI molecules from the films was studied by ¹H NMR experiments in D₂O to explain the antimicrobial properties of the PEI-based films against Staphylococcus aureus, with the DDGS–10% PEI films being the most active surface. Furthermore, the incorporation of copper ions into the different films enhanced their antimicrobial activity. Additionally, the starch–10% PEI film exhibited good swelling capacity in deionized water (~1500%), which decreased with the addition of salts (~250%). Instead, the DDGS–10% PEI film showed low swelling capacity in deionized water (~80%), with this capacity increasing with the addition of salts (~250%). The mechanical properties of the films improved considerably when 3% PEI was used. Full article

To achieve a scientific and objective evaluation of soil acidification, secondary salinization, and nutrient imbalance in old protected vegetable fields (OPVs) with over 30 years of cultivation history, a soil surface breeding vigorous moss was investigated. Here, quantitative laboratory analysis and mathematical statistics were employed to explore the spatial distribution of soil salinity and nutrients, as well as their relationships. The results revealed that OPVs exhibited slightly acidified values. The measured anions and cations in the soil salt composition constituted approximately 77% of the total ions. Among which, Ca²⁺ was the dominant cation, while SO₄²⁻ and NO₃⁻ were predominant anions. The total water-soluble salt (TDS) content of the surface soil reached 4.52 g kg⁻¹, exceeding the Chinese Saline Soils standard (1.0 g kg⁻¹) by 350%. In the OPVs, nitrate nitrogen was significantly higher than ammonium nitrogen, and available phosphorus and available potassium were generally abundant. Despite exhibited various soil health concerns, a field visit survey presented consistently high and stable yields in OPVs. We hypothesize that this seemingly contradictory finding may be attributable to several factors, including the abundance of divalent cations (Ca²⁺ and Mg²⁺), the soil fertility and water retention capacity of unsaturated salt-based suitable soil, as well as good soil aggregate structure. These factors had the potential to reduce the stresses on the soil. This study provided a foundational understanding of the nutrient and salinity status of soils in OPVs, offering valuable data and theoretical groundwork for future research endeavors. Full article

Soil salinity is a major global challenge affecting agricultural productivity and food security. This study explores innovative strategies to improve salt tolerance in soybean (Glycine max), a crucial crop in the global food supply. This study investigates the synergistic effects of S-nitroso glutathione (GSNO) and silicon on enhancing salt tolerance in soybean (Glycine max). Two soybean cultivars, Seonpung (salt-tolerant) and Cheongja (salt-sensitive), were analyzed for various physiological, biochemical, and genetic traits under salt stress. The results showed that the combined GSNO and Si treatment significantly improved several key traits, including plant height, relative water content, root development, nodule numbers, chlorophyll content, and stomatal aperture, under both control and salt stress conditions. Additionally, this treatment optimized ion homeostasis by enhancing the Na/K ratio and Ca content, while reducing damage markers such as electrolyte leakage, malondialdehyde, and hydrogen peroxide. The stress-responsive compounds, including proline, ascorbate peroxidase, and water-soluble proteins, were elevated under stress conditions, indicating improved tolerance. Gene expression analysis revealed significant upregulation of genes such as GmNHX1, GmSOS2, and GmAKT1, associated with salt stress response, while GmNIP2.1, GmNIP2.2, and GmLBR were downregulated in both varieties. Notably, the salt-sensitive variety Cheongja exhibited higher electrolyte leakage and oxidative damage compared to the salt-tolerant Seonpung. These findings suggest that the combination of GSNO and silicon enhances salt tolerance in soybean by improving physiological resilience, ion homeostasis, and stress-responsive gene expression. Full article

Diesel contamination in water bodies poses a significant environmental challenge due to the toxic effects of its water-soluble fraction (WSF) on aquatic ecosystems and human health. The aim of this work was the design of a new technological procedure for the purification of water contaminated with the WSF of diesel. The procedure is based on the adsorption of organic pollution on an organozeolite, after which the biodegradation of the adsorbed pollutant takes place. The material for obtaining organozeolite was a natural zeolite from the Zlatokop deposit (Vranje, Serbia). The zeolitic surface was modified with hexadecyltrimethylammonium bromide (HDTMA-Br), a cationic quaternary ammonium salt. The adsorption experiments, with initial WSF concentrations of 2.5–25 mg/L, at pH 6 and at 20 °C, were performed in a batch system using organozeolite, and the results showed that more than 90% of the WSF of diesel was removed, reaching equilibrium after 1 h. The maximum adsorbed capacity of organozeolite for the removal of the WSF of diesel fuel from water under the tested conditions was 22.2 mg/g. Equilibrium data were well fitted by a linear isotherm model, while a pseudo-second-order equation well fitted the kinetic data. After adsorption, a 15-day biodegradation experiment was carried out under batch conditions. The results showed that the examined consortium of microorganisms degraded 80% of the adsorbed contaminant. Additional respirometric analyses showed that, in parallel with the degradation of the contaminant, the degradation of the long-chain HDTMA ions at the surface of the organozeolite also occurred. To the best of our knowledge, this is the first study combining adsorption and biodegradation to remove the WSF of diesel from water. Full article

Chloride binding technology can effectively reduce the content of free chloride ions in seawater (used for cementitious materials), thereby extending the service life of seawater concrete structures. Currently, affordable and highly dispersed nanomaterials that can enhance the chloride binding capability of seawater cement are finite. This paper presents the first experimental study on N-doped graphene quantum dots (NGQDs), an innovative carbon nanomaterial with low price and high dispersibility, to strengthen the mechanical and chloride binding capabilities of seawater cement. Concretely, NGQDs are prepared through the hydrothermal process. The morphology and structure of NGQDs are measured by TEM, AFM, FTIR, and XPS. And the strengths and chloride binding performance of different specimens are analyzed by compressive/flexural strength tests and chloride adsorption equilibrium tests. The phase compositions of various specimens are analyzed by XRD, TGA/DTG, and SEM. The consequences indicate that the unique structure of the prepared NGQDs endows them with excellent water solubility and dispersibility. Notably, the introduction of NGQDs enhances the mechanical performance of seawater cement and 0.05 wt.% NGQDs have the greatest improvement effect. The compressive and flexural strengths of seawater cement containing 0.05 wt.% NGQDs increase by 8.21% and 25.77% after 28 d curing, respectively. Additionally, the seawater cement containing 0.2 wt.% NGQDs have the best chloride binding capability and are 41.08% higher than the blank group. More importantly, the chloride binding mechanism is that NGQDs accelerate seawater cement hydration, resulting in an increased formation of hydrated calcium silicate (C–S–H) and Friedel’s salt (Fs), thereby strengthening the physisorption and chemical combination of chloride. This study highlights an inexpensive and highly dispersible nanomaterial to heighten the stability of seawater concrete structures, opening up a new path for the better utilization of seawater resources. Full article

Soil salinization is an important factor that limits crop production. The effects of spraying salicylic acid (SA) during the grain-filling stage on the salt tolerance of progeny seeds in wheat (Triticum aestivum L.) were investigated in this study. The results showed that spraying SA during the grain-filling stage significantly increased the grain weight and yield of wheat plants. Meanwhile, the seeds from the SA-treated plants showed a higher germination rate, length and dry mass of the coleoptile and radicle, and a lower mean germination time compared to the seeds of water-treated plants under the salt germination condition, indicating that SA pretreatment during the grain-filling stage could effectively improve the salt tolerance of progeny seeds in wheat. SA pretreatment significantly increased the activities of amylases and the respiration rate, accompanied by a decrease in starch content, and a higher accumulation in the level of soluble sugars and adenosine triphosphate (ATP) in the germinated seedlings compared to the water pretreatment under salt stress. In addition, SA pretreatment obviously alleviated the increase in malondialdehyde (MDA) content and the reactive oxygen species (ROS) release rate in seedlings by activating antioxidant enzymes (superoxide dismutase (SOD) and peroxidase (POD)) under salt stress. Moreover, the seedlings of the SA-treated plants showed lower Na⁺ and higher K⁺ contents compared to the seeds of water-treated plants under salt stress. The results of this study indicate that spraying SA during the grain-filling stage improves the capacity of offspring seeds to maintain osmotic and ion balance and redox homeostasis under salt stress, thereby conferring salt tolerance to the wheat seeds. Full article

A cold atmospheric-pressure He-plasma jet (CAPPJ) interacts with air and water, producing reactive oxygen and nitrogen species (RONS), including biologically active ions, radicals, and molecules such as NO_x, H₂O₂, HNO₃, HNO₂, and O₃. These compounds can activate interfacial redox processes in biological tissues. The CAPPJ can oxidize N₂ to HNO₃ and water to H₂O₂ at the interface between plasma and water. It can also induce the oxidation of water-soluble redox compounds in various organisms and in vitro. This includes salicylic acid, hydroquinone, and mixtures of antioxidants such as L (+)-ascorbic acid sodium salt with NADPH. It can react with redox indicators, such as ferroin, in a three-phase system consisting of air, CAPPJ, and water. Without reducing agents in the water, the CAPPJ will oxidize the water and decrease the pH of the solution. When antioxidants such as ascorbate, 1,4-hydroquinone, or NADPH are present in the aqueous phase, the CAPPJ oxidizes these substances first and then oxidizes water to H₂O₂. The multielectron mechanisms of the redox reactions in the plasma-air/water interfacial area are discussed and analyzed. Full article