High Copper Concentrations Research Articles

In situ alloying of AlCuSi using dual-wire-directed energy deposition with plasma

Abstract The current research explores additive manufacturing of a multi-phase material using dual-wire plasma-directed energy deposition technology. With this approach, new materials can be designed and tested easily on the basis of commercially available consumables. In this work, AlSi5 and CuAl8 solid wire consumables are used to produce a specific AlCuSi alloy by controlling the welding parameters and the wire feed ratio. Initial experimentation results in an alloy with 85.7 at.% aluminum, 8.4 at.% copper, 2.7 at.% silicon, and 3.2 at.% magnesium, but with some instabilities during the process. The presence of magnesium in the chemical composition could be related to plasma interaction with the substrate during the welding process. After optimizing the process parameters, the chemical composition obtained is about 76.3 at.% aluminum, 19.9 at.% copper, and 3.8 at.% silicon. Using microstructural analysis via light and scanning electron microscopy, defects such as pores and inadequately melted Cu wire material are observed in all materials produced. Although the optimization of the melting process improved the microstructure, it also increased the copper content, which in turn exerts a significant influence on the mechanical properties. Mechanical testing indicates significant embrittlement. The results underscore that the microstructure is heavily influenced by the chemical composition. Microstructural changes caused by the higher copper content, i.e., in particular the increase of the volume fraction of brittle intermetallic phases such as θ-Al2Cu, result in severe embrittlement of the obtained materials, denoted by higher hardness and reduced toughness. We conclude that the use of dual-wire plasma additive manufacturing can develop new materials by in situ alloying.

ICEmST contributes to colonization of Salmonella in the intestine of piglets

Salmonella enterica serovar 4,[5],12:i:- sequence type 34 (ST34) has recently become a global concern for public and animal health. The acquisition of mobile genetic element ICEmST, which contains two copper tolerance gene clusters, cus and pco, influences the epidemic success of this clone. Copper is used as a feed additive in swine at levels that potentially lead to selection pressure for Enterobacteriaceae; however, it remains unclear whether the copper tolerance system of ICEmST functions in vivo. We performed competition assays with Salmonella 4,[5],12:i:- ST34 wildtype (WT) and deletion mutants of ICEmST (ΔICEmST, Δcus, and Δpco) in groups of mice fed 0, 150, and 500 ppm CuSO4. In the competition of WT against ΔICEmST and Δcus, the competitive index of the 500 ppm-fed group was significantly lower than that of the 0 ppm-fed group. In the swine experiment, all individuals were fed 150 ppm CuSO4. The number of ICEmST-positive strain in the feces was significantly greater than that of ICEmST-negative strain. The serum inflammatory markers were significantly increased in swine infected with the ICEmST-positive strain. These data suggest that ICEmST, especially cus, provides Salmonella with the ability to colonize in the intestine, even at high copper concentrations, leading to swine salmonellosis.

Study of the Impact of Copper on Soil Organisms and Tomato Quality

Background: The aim of our work is to assess the impact of copper-contaminated soil on tomato fruit and soil organisms. Excessive use of copper-based pesticides has many consequences for soil biology and food quality. Methods: Our study was carried out in a section of a tomato plot in the Mostaganem region of northern Algeria. The plot was contaminated with copper, at different doses D1 (10 mg Cu Kg-1), D2 (100 mg Cu Kg-1), D3 (200 mg Cu Kg-1) and D4 (300 mg Cu Kg-1) in separate blocks. The concentrations of copper and carbohydrates and the homogeneity of the wells were assessed in order to determine the quality of the tomatoes in relation to the levels of soil contamination. Furthermore, the respiratory activity of the microorganisms and the feeding activity of the soil fauna were assessed. Result: The highest copper concentrations were 1.5±0.17 mg Cu Kg-1 and 2.05±0.3 mg Cu Kg-1 in the sites contaminated by the highest doses D3 and D4 and the highest carbohydrate concentrations were 53.03±1.38 g kg-1 and 61.15±0.65 g kg-1 in these two sites. Microbial respiration values were lowest in D3, with 8.3.10-4 ± 3.6.10-4 mg CO2 g-1 h-1 and in D4, with 1.5.10-3 ±1.4.10-4 mg CO2 g-1 h-1. In addition, wildlife feeding activity was low at both sites, with values of 27.56±17.77 % for the D3 site and 37.5±17.48 % for the D4 site. Our study has shown that copper contamination of soils affects the biological activities of soil organisms.

Assessment of Native Wild Macromycete Strains for Mycoremediation of Copper-Contaminated Soils in Coffee Plantations

This study evaluates the mycoremediation potential of wild mushroom species from Chiapas, Mexico, specifically for high copper concentrations. Nine fungal carpophores were collected from tropical forests near coffee plantations. The morphological characteristics of the fungal strains and fruiting bodies were analyzed. Each specimen was identified through sequencing using the ITS1 and ITS4 primers. The ability to tolerate different concentrations of copper was evaluated by determining the fungal mycelial growth inhibition potential. Copper bioaccumulation by the fungi was quantified using biosorption assays with atomic absorption spectrophotometry. The enzymatic activity of laccase, lignin peroxidase, and manganese peroxidase from the fungal species was also determined in the presence of copper. Phylogenetic analysis identified the fungal species as Agaricus bisporus, A. subrufescens, Calvatia fragilis, Ganoderma coffeatum, G. lucidum, Pleurotus djmor, P. floridanus, Trametes elegans, and T. versicolor, all classified within the Agaromycetes class. The nine fungal species exhibited varying abilities to tolerate Cu2+ concentrations from 30 to 100 mg L−1. At 30 and 60 mg L−1 Cu2+, the G. lucidum H14-35 strain demonstrated the highest biosorption capacity, reaching 76.97%. Overall, the mushrooms in this study showed strong Cu2⁺ tolerance and biosorption, making them promising biomaterials for remediating copper-contaminated soils.

Impact of a Complex Passivating Agent on Heavy Metal Immobilization in Pig Manure and Plant Development

In order to immobilize heavy metals in livestock and poultry manure and promote the safe utilization of pig manure resources, this experiment utilized three types of dried pig manure mixed with soil as raw materials. A combination of biochar and bentonite was established, including treatments with the addition of pig manure (CZ), 2.5% bentonite (F1), 7.5% bentonite (F2), 2.5% biochar (F3), 7.5% biochar (F4), 2.5% biochar + 2.5% bentonite (F5), 2.5% biochar + 7.5% bentonite (F6), 7.5% biochar + 2.5% bentonite (F7), 7.5% biochar + 7.5% bentonite (F8), and with zero addition (CK). After the passivation treatments had been applied, a soybean pot experiment was established to measure various physiological indicators at different soybean development stages. The results revealed that the passivated Cu was predominantly in the reduced and residual states. The passivation rates for F8 in LPS, F7 in MPS, and F8 in HPS were 34.10%, 29.90%, and 39.50%, respectively. Among the three concentrations of a pig manure–soil mixture, the impact of low copper concentration on soybean growth was relatively minimal, whereas medium and high copper concentrations significantly impaired soybean health, resulting in varying degrees of interveinal chlorosis and leaf yellowing from the tip to the base of young leaves, thereby affecting photosynthesis. The combined application of biochar and bentonite enhanced copper passivation and facilitated soybean growth and development.

Socio-Demographic Determinant Factors for Serum Iron, Copper, Zinc, and Selenium Concentrations Among U.S. Women of Childbearing Age.

Trace elements (TEs) are essential nutrients for the human body and have a significant impact on fertility and hormone levels in women of reproductive age, underscoring the importance of understanding sociodemographic variations in their concentrations within this population. To investigate the socio-demographic factors influencing blood concentrations of four essential TEs, including iron, zinc, copper, and selenium among women of reproductive age. A cross-sectional analysis of women aged 20-44 years was performed using the National Health and Nutrition Examination Survey, 1999-2018. Serum iron data were analyzed for 9211 women across 10 cycles, while serum copper, zinc, and selenium data were available for 1027 women across 3 cycles. Generalized linear and logistic regressions examined the individual associations of socio-demographic factors, including age, race and ethnicity, education, and poverty index ratio, with iron, zinc, copper, and selenium concentrations treated as continuous and categorical outcomes, respectively. A qualitative heatmap explored the joint associations between the socio-demographic factors and the four essential TEs. Reduced iron concentrations and increased risks of insufficiency occurred in older, Black, low-education, or low-income women. Black women were more likely to have lower zinc and selenium concentrations and an increased risk of zinc insufficiency but higher copper concentrations. The qualitative heatmap found that older, Black, low-education, and low-income women generally had lower concentrations of the four TEs, particularly iron (β = -0.10; p < 0.01). Socially disadvantaged women are more likely to present with lower TE concentrations, and these specific population groups should be targeted by replenishment planning by public health initiatives.

Extraordinary Mechanical Properties of a Field‐Assisted Sintering Technique/Spark Plasma Sintering Consolidated Stainless Steel with High Copper Content of 9 wt%

The solidification behavior of a novel X1CrCuNiN 18‐9‐6 (concentrations in wt%) stainless steel is studied by thermodynamic calculations and corresponding microstructure investigations. The thermodynamic calculations of the X1CrCuNiN 18‐9‐6 steel predict a metastable austenitic structure, which is verified by microstructural analyses. In the as‐cast state before heat treatment, a few copper precipitates, mostly over 50 μm in size, are visible, which are located exclusively in the interdendritic regions. The electrode inert gas atomization process is applied to produce a steel powder using a pre‐material in as‐cast state with significantly increased Cu content of 9 wt%. After atomization, despite the rapid cooling, micrometer‐sized copper precipitates form again, which are homogeneously distributed in the microstructure, but are mostly less than 10 μm in size and thus much finer than in the initial cast state. The short processing times during field‐assisted sintering technique/spark plasma sintering makes it possible to produce a bulk material with a porosity of less than 1%. Miniature samples produced from the as‐sintered material exhibit uniform elongation values of 30%–40% with a tensile strength of about 640 MPa under tensile loading conditions.

Investigation of wear and transverse rupture strength of AA2219/ZrO2/B4C hybrid composite materials prepared with 3D ball mixer and produced by spark plasma sintering

ABSTRACT Aluminum alloys have advanced to meet the growing demand for strong, lightweight materials. The 2219 aluminum alloy has gained popularity due to its superior mechanical properties and high copper content. However, despite these improvements, the wear characteristics of metal matrix composites with ceramic reinforcements have been suboptimal. This study aims to develop metal matrix composites that improve the mechanical and wear properties of AA2219 aluminum alloy. A homogeneous mixture was created using a 3D mechanical mixer/miller apparatus. ZrO2 and B4C reinforcements were added to the matrix in ratios of 5%, 10%, and 15%, including hybrid composites with both reinforcements. Mechanical and wear characteristics were analyzed, and a 3D profilometer was used to evaluate wear properties and determine tribological parameters. The results showed that the pulverized reinforcement particles were uniformly dispersed within the matrix. The sample with a hybrid reinforcement comprising 15% of the total composition exhibited the highest hardness, measuring 164.96 hV. This study demonstrates that incorporating ceramic reinforcements in specific ratios can significantly enhance the mechanical and wear properties of 2219 aluminum alloy composites.

Heavy metal immobilisation with microbial-induced carbonate precipitation: a review

Microbial-induced carbonate precipitation (MICP) is a promising bioremediation technology for heavy metal immobilisation. This review explores the applications and efficacy of MICP in environmental challenges. It provides a comprehensive overview of the mechanism, primarily through ureolysis, detailing the process from urea hydrolysis to heavy metal precipitation as carbonate minerals. Alternative pathways such as photosynthesis and nitrate reduction are also discussed, highlighting the broad applicability of MICP. The review covers the historical evolution and advancements of MICP as a sustainable solution for heavy metal contamination. Recent studies demonstrate the efficiency of MICP in achieving high removal rates in diverse environments. The sustainable operation, precise targeting of heavy metal species, and versatility of MICP are examined. Challenges such as high copper concentrations, acidic conditions, and cost considerations are addressed. The article provides future directions and solutions to these challenges, including leveraging machine learning for optimal performance and enhancing cost considerations through detailed analyses. This review improves understanding of MICP’s potential, provides a valuable resource for researchers in environmental engineering and the built environment, and encourages innovative approaches within these fields.

Combinational supplements of organic amendments alleviate copper-induced stress in Withania coagulans (Dunal)

Heavy metal contamination in the whole biosphere, especially in soil, is accountable for most of the adverse consequences influencing the prosperity of fauna and flora. A pot experiment was designed to investigate the effects of Copper (Cu) with and without combinational supplements of organic amendments (OAs) [cow dung citric acid and amino acid (L-glutamine)] on various physiological and biochemical parameters of Withania coagulans. The peat moss soil was treated with two concentrations of Cu [ and (10mM, 15mM)] alone and/or with organic amendments [cow dung (10g, 15g), citric acid (05mM, 10mM), and amino acid (05mM, 10mM)]. After four weeks, the results revealed that a higher concentration of Cu significantly reduced the plant agronomic traits by 31% (Number of leaves), 17% (Shoot length), 24% (Root length), 19% (Fresh weight), and 35% (Dry weight), whereas photosynthetic pigments by 34% carotenoids, 33% chlorophyll a (chl a), and 16% chlorophyll b (chl b) compared to control. Moreover, it was noticed that the combination of organic amendments alleviates the negative effects of a higher concentration of Cu on agronomic traits and photosynthetic pigments of a tested plant. The additional supplements of organic amendments improved the plant physiology and enhanced the antioxidant enzyme activities to overcome the induced oxidative damage by the higher concentration of copper. Our findings showed that higher doses of Cu had an impact on the agronomic and biochemical characteristics of Withania coagulans, whereas the addition of organic amendments alleviated that impact of Cu.

Assessment of trace metal elements in selected Plants around the vicinity of Ebedei Gas Flaring Station located at Ebedei Village, Ukwani Local Government Area, Delta State, Nigeria

This study evaluated the trace metal elements in selected plants around the Ebedei Gas Flaring Station, Ukwani Local Government Area, Delta State, Nigeria. The plants analyzed include Azadirachta indica, Cymbopogon citratus, Moringa oleifera, Carica papaya) and Alstonia boonei. The analysis revealed that Alstonia boonei had the highest concentration of Copper at 6.87 mg/kg, while the lowest concentration of Lead (0.06 mg/kg) was found in Carica papaya. The trace metal levels in the plants ranged from 0.06 mg/kg for Lead to 6.87 mg/kg for Copper, with Azadirachta indica showing moderate levels across all measured metals. These concentrations were within the permissible limits set by WHO for vegetables, indicating no immediate threat to consumers. However, the study highlights the potential for bioaccumulation over time, which could elevate these levels and pose health risks. The study thus recommends conducting regular monitoring of trace metal levels in plants around gas flaring sites to prevent potential health hazards. In addition, soil remediation strategies should be implemented to reduce metal uptake by plants and public awareness campaigns should be carried out to educate the local population on the risks of consuming plants from contaminated areas.

Accumulation of Heavy Metals in the Leaves of Some Woody Plants in Osh City

Pollution of the environment with harmful substances occupies a leading place among global environmental problems. This phenomenon is closely related to anthropogenic activity, especially in cities. The origin and chemical nature of harmful substances are different, but heavy metals occupy a special place among them. Over the past ten years, research aimed at studying the distribution of heavy metals in the environment and their accumulation in plants has significantly developed. Because the Sustainable Development Goals adopted by the UN in 2015 provide for by 2030, to reduce the negative environmental impact of cities per capita, including by paying special attention to air quality and the removal of urban and other waste. The purpose of our research was to determine the characteristics of the accumulation of heavy metals in the leaves of trees and shrubs growing in the park areas of Osh. The trees selected as objects were Salix babylonica L., Acer pseudoplatanus L., Populus ×canescens (Aiton) Sm., Platanus orientalis L., Juniperus virginiana L., planted in park areas near highways. The concentration of heavy metals was determined by the atomic absorption method in the Central Laboratory State Enterprise under the Ministry of Natural Resources, Ecology and Technical Control of the Kyrgyz Republic. Quantitative analysis revealed the presence of some heavy metals: manganese, copper, lead, strontium and zinc in all plant samples. Laboratory tests showed a high concentration of copper, exceeding the MAC. Based on the research results, we note the need to continue studying the influence of heavy metals on the physiological processes of various tree species in Osh and expanding the geography of research in the city’s microdistricts.

Cu Concentration in Vegetable-Cultivated Soil: Comparison Between Open Fields and Protected Environments in Brazil

High copper (Cu) concentration in soils used for vegetable production is an agricultural, social and environmental issue. The excess of Cu in soil can cause toxicity in plants, reducing growth and yields. Moreover, Cu can also be absorbed and accumulated in edible organs, increasing risks for human health. This study aimed to compare Cu fractions in soils: (1) non-cultivated, natural soil (NC), (2) soils cultivated with open field crops (FCs) and (3) soils cultivated in controlled environments (CEs). The survey was carried out on 25 sites in Rio Grande do Sul (Southern Brazil), with each site containing the three types of soils described above. From these sites, the four with the highest soil Cu concentrations were selected to compare soluble (Cu-CaCl2), available (Cu-EDTA) and total (Cu-EPA) Cu. Both total and available soil Cu concentration in soil solution, in CE and FC areas were higher than in NC. At sites 23R1 (Oxisol) and 11R1 (Molisol) the soluble and available Cu content was higher in the FC environment than in CEs, and the same was observed for the total Cu content at sites 23R1 (Oxisol) and 9R1 (Molisol). Some FC soils showed total Cu concentrations higher than the limits established by Brazilian environmental legislation, being, as a consequence, potentially contaminated. Soil monitoring and cropping practices must be adopted to reduce the Cu content in soils of vegetable crops in this region.

Tolerance of free-living larval stage of a parasite from coastal mining areas in northern Humboldt Current to copper pollution at low and high temperatures.

Metal pollution is a worldwide problem and one of the greatest threats to ecosystem integrity due to its toxicity, persistence, and bioaccumulation in biological systems. Anthropogenic pollution impacts marine organisms and host-parasite dynamics, with the northern Chilean coast experiencing elevated copper levels in marine waters and sediments due to mining activities. In this study, we assessed the effects of exposure to copper concentrations at low and high-water temperatures on the survival and longevity of the marine parasite Himasthla sp. cercariae (Trematoda: Digenea) using the snail Echinolittorina peruviana as its first intermediate host. Snails were collected from intertidal rocky pools in northern Chile (23°S). To assess parasite survival and longevity, cercariae were collected from a pool of infected snails, and their mortality was recorded every 6 hours until all cercariae were dead. In a preliminary experiment conducted at 19°C, cercariae were exposed to different copper concentrations (0.2, 1.5, 3.0, and 6.0 mg/L) for 78 hours. Cercariae showed tolerance to copper. However, at the higher copper concentration (6 mg/L), survival was negatively impacted (50%) at 54 hours. In contrast, at the lower concentration (0.2 mg/L) and in the control group, cercariae sustained a 73-90% survival rate even after 54 hours. Based on these findings, we conducted subsequent experiments involving two copper treatments (0.2 and 3.0 mg/L) and two temperatures (14 and 22°C). Survival and longevity were significantly higher at lower temperature and copper concentration (14°C and 0.2 mg/L). Conversely, at higher temperature and copper concentration (22°C and 3 mg/L), survival and longevity decreased to only 66 hours. Our results show that Himasthla sp. cercariae tolerated most copper concentrations, with vulnerability observed primarily in high water temperatures, indicating an adverse effect on cercariae performance. This study contributes valuable insights into how parasites respond to environmental pollution, in marine ecosystems influenced by anthropogenic activities.

Fundamentals of copper(II) adsorption on phyllosilicate minerals relevant to crud formation in solvent extraction from heap leach liquors

Because of the common presence of different silicate minerals, like kaolinite, montmorillonite and muscovite as gangue minerals in the beneficiation of copper oxide ores, the interaction between copper(II) ions in solution and each of these minerals is a field of strong interest, considering their implications on the aggregation of these minerals in the extreme pH conditions typical of hydrometallurgical unit operations for copper production. After copper adsorption isotherms determination at pH 2 and 4, specific adsorption data were fitted to both Langmuir and Freundlich models. It was found that adsorption is systematically larger at pH 4, and that montmorillonite is the mineral that displays a larger adsorption capacity, as in principle expected by its larger cation exchange capacity, CEC. A good fitting to the Langmuir model was obtained for the three samples, and montmorillonite also appears to conform to Freundlich isotherm predictions, as the tested concentrations of copper(II) do not allow to reach saturation. Furthermore, some desorption is measured for kaolinite and muscovite at the highest copper concentrations, probably because of significant interactions between the adsorbed ions. No such desorption was detected in montmorillonite samples. An XPS analysis of the surfaces of the three minerals suggests that copper adsorption in kaolinite is not associated to a cation exchange process but rather to electrostatic interactions between silica-like faces of the clay. In contrast, ionic exchange of structural calcium (for montmorillonite) or potassium (in the case of muscovite) seems to be the predominant mechanism of Cu(II) adsorption in the other two samples. Electrophoretic mobility determinations agree with this hypothesis: the mobility (always negative, with no traces of charge inversion) decreases in absolute value when kaolinite particles are in contact with solutions of increasing copper concentration at pH 2 or pH 4. On the other hand, the electrophoretic mobility values of muscovite and montmorillonite showed a weak pH and copper concentration dependence, a result that matches well with the ion exchange processes detected in the XPS measurements.

Copper biomarkers and their relationship with parameters of insulin resistance in obese women.

Some studies have demonstrated the involvement of high concentrations of copper in the manifestation of insulin resistance in individuals with obesity. The objective of this study was to evaluate the copper nutritional status and its relationship with parameters of glycemic control in women with obesity. An observational case-control clinical study involving 203 women aged between 20 and 50years, divided into two groups: obese (n = 84) and eutrophic (n = 119). Body weight, height and waist, hip and neck circumferences, dietary copper intake, copper biomarkers, determine ceruloplasmin activity and glycemic control parameters were measured. It was observed that women with obesity had higher copper concentrations in plasma and lower concentrations in erythrocytes when compared to the control group. Analysis of glycemic control parameters revealed a statistically significant difference in fasting blood glucose (p < 0.05) between groups. The study identified a significant positive correlation between plasma copper and fasting insulin values and the Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) index (p < 0.05). The results of this study demonstrate that obese women have high copper concentrations in plasma and lower concentrations in erythrocytes. Furthermore, the significant positive correlation between plasma copper and fasting insulin and HOMA-IR index suggests the influence of this mineral on glycemic control parameters in obese women.

Optimization of Copper-Ammonia-Sulfate Electrolyte for Maximizing Cu(I):Cu(II) Ratio Using pH and Copper Solubility

An investigation has been carried out to understand the solution chemistry of the Cu-NH−-SO4−2 system, focusing on the effect of pH on the solubility of copper in the solution and maximizing the Cu(I):Cu(II) ratio. A Pourbaix diagram for the Cu-N-S system has also been created using the HSC Chemistry software for a wide range of Cu-NH3 species, unlike most other studies that focused only on Cu(NH3)42+ and Cu(NH3)52+ (Cu(II)) as the dominant species. The Pourbaix diagram demonstrated that the Cu(I) exists as Cu(NH3)2+, while the Cu(II) species are present in the system as Cu(NH3)42+ and Cu(NH3)52+, depending upon the Eh and pH of the solution. Copper precipitation was observed in the electrolyte at pH values less than 8.0, and the precipitation behavior increased as the pH became acidic. The highest Cu(I):Cu(II) ratio was observed at higher pH values of 10.05 due to the higher solubility of copper at higher alkaline pH. The maximum Cu(II) concentration can be achieved at 4.0 M NH4OH and 0.76 M (NH4)2SO4. In the case of low pH, the highest Cu(I):Cu(II) ratio obtained was 0.91 against the 4.0 M and 0.25 M concentrations of NH4OH and (NH4)2SO4, respectively. Meanwhile, at high pH, the maximum Cu(I):Cu(II) ratio was 15.11 against the 0.25 M (NH4)2SO4 and 4.0 M NH4OH. Furthermore, the low pH experiments showed the equilibrium constant (K) K &lt; 1, and the high pH experiments demonstrated K &gt; 1, which justified the lower and higher copper concentrations in the solution, respectively.

The balance between alleviating copper damage and maintaining root function during root pruning with excessive copper.

Coating high concentrations of copper (Cu) on the inner wall of containers can efficiently inhibit root entanglement of container-grown seedlings. However, how the protective and defensive responses of roots maintain root structure and function during Cu-root pruning is still unclear. Here, Duranta erecta L. seedlings were planted in the containers coated with 40 (T1), 80 (T2), 100 (T3), 120 (T4), 140 (T5) and 160 (T6) g L-1 Cu(OH)2 with containers without Cu(OH)2 as the control. Although T5 and T6 produced the best inhibitory effect on root entanglement, root anatomy structure was damaged. T1 and T2 not only failed to completely control root circling, but also led to decreased root activity and stunted growth. Cu(OH)2 treatments significantly increased lignin concentration of roots with the highest values at T3 and T4. Compared with T3, seedlings at T4 had higher height, biomass and root activity, and no significant root entanglement. Excessive Cu accumulation in Cu(OH)2 treatments changed the absorption of other mineral nutrients and their allocation in the roots, stems and leaves. Overall, Ca was decreased while Mg, Mn, Fe and K were increased, especially K and Mn at T4 which is related to defense capacity. The results indicate that there is a Cu threshold to balance root entanglement control, defense capacity and nutrient uptake function under excessive Cu for container-grown D. erecta seedlings.

4-Diphenylaminobenzaldehyde-formulated isonicotinohydrazide for the rapid recognition of Cu2+ ions; Application of RGB tool, pharmaceutical samples, and DFT studies

High copper concentrations have been linked to several harmful illnesses in humans and negatively affect the kidneys and liver. The design and synthesis of simple and effective chemosensors for recognizing copper (Cu2+) ions are extremely significant. However, most of the colorimetric chemosensors have been developed using an intramolecular charge transfer binding mechanism based on donor-acceptor conjugation systems. This study aimed to fabricate a novel Schiff base colorimetric chemosensor, N'-(4-(diphenylamine) benzylidene) isonicotinohydrazide (DPBA-INH), with high sensitivity and selectivity towards copper ions in the semi-aqueous medium (DMSO: H2O, 7:3, v/v). The synthesized receptor DPBA-INH was distinguished using various spectroscopic methods, including NMR analysis, Fourier transform infrared spectroscopy, HRMS, and ultraviolet-visible (UV–vis) spectroscopy. When exposed to sunlight, the receptor DPBA-INH with Cu2+ ion complexation exhibited a color change from orange to pale yellow. A Job's plot and electrospray ionization mass spectra confirmed the presence of complexation at a stoichiometric binding proportion of the receptor to Cu2+ ions of 1:1. The receptor DPBA-INH interacts with Cu2+ ions in a 1:1 stoichiometric manner with a detection limit of 1.40 × 10−7 M. The experimental results were supported by a theoretical DFT study. Moreover, the receptor effectively measured Cu2+ ions in pharmaceutical samples and test strip analyses. Furthermore, the rapid colorimetric recognition of Cu2+ ions in a semi-aqueous medium was achieved using DPBA-INH, which was demonstrated to be an excellent receptor. Notably, DPBA-INH was employed to detect copper ions in real water samples.

The antibacterial activity of the copper for Staphylococcus aureus 124 and Pseudomonas aeruginosa 18 depends on its state: metalized, chelated and ionic

The hypothesis that the antibacterial effect of copper depends on its state was tested. It was studied the antibacterial effect of copper applied to the fabric, copper in chelated and free (ionic) forms on the growth intensity of Staphylococcus aureus 124 and Pseudomonas aeruginosa 18 in the in vitro system after a single or “primary” contact. Classical microbiology methods were used. Copper was applied to the fabric by magnetron and arc planar discharge systems, and the culture of microalgae Dunaliella viridis, resistant to the action of high concentrations of copper, was used to obtain copper in chelated form. It was shown that a thin layer of copper (3 μm) applied to the fabric showed pronounced antibacterial activity against Staphylococcus (85 % compared to the antibiotic meropenem) and less pronounced activity against Pseudomonas, which is resistant to meropenem. Copper in ionic form inhibited the growth of Staphylococcus aureus 124 as well as the antibiotic, and also effectively inhibited the growth of Pseudomonas aeruginosa 18 i.e., copper ions did not have species specificity like the antibiotic. Components of Dunaliella viridis microalgae cells had weakly expressed antibacterial effect to these types of bacteria, and supplementary addition of copper sulfate to the biomass of microalgae led to an increase of their antibacterial activity and this is more pronounced for microalgae culture in which the ratio « chelated/ionic » forms of copper is shifted to the ionic form. It was shown that the antibacterial activity of microalgae biomass after the first introduction into the tested bacterial cultures depends on the amount of free or “weakly bound” with cell components copper ions. It is suggested that the antibacterial effect of fabric with a thin layer of copper may be determined by two mechanisms: the action of copper ions and mechano-bactericidal effects, while chelated forms of copper may have a prolonged effect on bacterial cultures.