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Three Fe3O4 magnetic solvent-free nanofluids with different amine-based coronal layer structures are synthesized and characterized by using magnetic Fe3O4 as the core, silane coupling agent as the corona, and polyether amines with different graft densities and chain lengths as the canopy. The concentration of heavy metal ions after adsorption is measured by atomic absorption spectrometry (AAS) to study the effect of Fe3O4 magnetic solvent-free nanofluids on the adsorption performance of the heavy metal ions lead (Pb(II)) and copper (Cu(II)) in water. The adsorption of Fe3O4 magnetic solvent-free nanofluid was explored by changing external condition factors such as adsorption contact time and pH. Additionally, the adsorption model is established. The magnetic solvent-free nanofluid is separated from water by applying an external magnetic field to the system, and desorption and cyclic adsorption tests are carried out. Based on the adsorption mechanism, the structure design of Fe3O4 magnetic solvent-free nanofluid was optimized to achieve optimal adsorption performance. [ABSTRACT FROM AUTHOR]

Environmental water contamination, particularly by heavy metal ions, has emerged as a worldwide concern due to their non-biodegradable nature and propensity to accumulate in soil and living organisms, posing a significant risk to human health. Therefore, the effective removal of heavy metal ions from wastewater is of utmost importance for both public health and environmental sustainability. In this study, we propose and design a membrane consisting of fluorographene (F-GRA) nanochannels to investigate its heavy metal ion removal capacity through molecular dynamics simulation. Although many previous studies have revealed the good performance of lamellar graphene membranes for desalination, how the zero-charged graphene functionalized by fluorine atoms (fully covered by negative charges) affects the heavy metal ion removal capacity is still unknown. Our F-GRA membrane exhibits an exceptional water permeability accompanied by an ideal heavy metal ion rejection rate. The superior performance of F-GRA membrane in removing heavy metal ions can be attributed to the negative charge of the F-GRA surface, which results in electrostatic attraction to positively charged ions that facilitates the optimal ion capture. Our analysis of the potential of mean force further reveals that water molecule exhibits the lowest free energy barrier relative to ions when passing through the F-GRA channel, indicating that water transport is energetically more favorable than ion. Additional simulations of lamellar graphene membranes show that graphene membranes have higher water permeabilities compared with F-GRA membranes, while robustly compromising the heavy meal ion rejection rates, and thus F-GRA membranes show better performances. Overall, our theoretical research offers a potential design approach of F-GRA membrane for heavy metal ions removal in future industrial wastewater treatment. [ABSTRACT FROM AUTHOR]

The land application of sewage sludge can cause different environmental problems due to the high content of potentially toxic elements (PTEs). The objective of this study was to compare the effect of urban biological sewage sludge (i.e. the waste of activated sludge process) and its derived biochar as the soil amendments on the bioavailability of PTEs and their bioaccumulation by corn (Zea mays L.) under two months of greenhouse conditions. The soil was treated by adding biochar samples at 0 (control), 1, 3, 5% w/w. The diethylenetriamine pentaacetic acid (DTPA)-extractable concentrations of PTEs including Zn, Pb, Cd, Cr, Ni, Fe, and Cu in soil and their accumulation by plant shoot and root were measured. Conversion of the biological sewage sludge into the biochar led to decrease the PTEs bioavailability and consequently decreased their contents in plant tissues. The DTPA extractable metal concentrations of produced biochar in comparison to the biological sewage sludge reduced 75% (Cd), 65% (Cr), 79% (Ni and Pb), 76% (Zn), 91% (Cu) and 88% (Fe). Therefore, the content of Ni, Fe, Zn and Cd in corn shoot was decreased 61, 32, 18 and 17% respectively in application of 5% biochar than of raw sewage sludge. Furthermore, the application of 5% biochar enhanced the physiological parameters of the plants including shoot dry weight (twice) and wet weight (2.25 times), stem diameter (1.70 times), chlorophyll content (1.03 times) in comparison to using 5% raw sewage sludge. The results of the study highlight that application of the biochar derived from urban biological sewage sludge in soil could decrease the risk of PTEs to the plant. [ABSTRACT FROM AUTHOR]

Incineration is a common method in municipal solid waste management, which has several advantages such as reducing the volume of waste, but with concerns about exhaust gas and ash management. In this study, heavy metals in bottom ash, secondary furnace ash and fly ash of two waste incinerators in Tehran and Nowshahr were analyzed and its control in cement production was investigated. For this purpose, twelve monthly samples of three types of incinerator ash were analyzed. By combining the studied ashes in the raw materials, the quantity of metals in the cement was analyzed. Finally, by investigating four scenarios based on quantitative variations in the routes of municipal solid waste, ash quantity and the related risk caused by its heavy metals were studied. The results showed that the concentration of heavy metals in the three ash samples of the studied incinerators was 19,513–23,972 µg/g and the composition of the metals included Hg (less than 0.01%), Pb (2.93%), Cd (0.59%), Cu (21.51%), Zn (58.7%), As (less than 0.01%), Cr (15.88%), and Ni (0.91%). The best quality of produced cement included 20% ash and 10% zeolite, which was the basis of the next calculations. It was estimated that the reduction of the release of metals into the environment includes 37 gr/day in best scenario equal to 10.6 tons/year. Ash solidification can be considered as a complementary solution in waste incinerator management. [ABSTRACT FROM AUTHOR]

Background: The objective was to investigate self-reported hand eczema, and skin complaints at other skin locations among workers exposed to particulate matter, especially ultrafine particles. Method: We conducted a cross-sectional study on workers from one ferro-silicon smelter plant, eight chimney sweeper stations and one firefighter station across Norway. Participants answered an extended version of the Nordic Occupational Skin Questionnaire (NOSQ-2022), with additional questions about whole-body skin complaints and visible dust deposition. Results are presented as descriptive data using firefighters as reference group. Odds ratio (OR) was calculated using logistic regression on lifetime prevalence of hand eczema adjusted for potential confounders and mediators. P-values were calculated using likelihood ratio test against the crude OR. Results: A total of 186 participants answered the questionnaire: 74 chimney sweepers, 52 firefighters and 60 smelter workers. Participation rate was 95.0, 94.5 and 63.6%, respectively. Lifetime prevalence of hand eczema was 9.5, 9.6, and 28.3%, respectively. The point prevalence of hand eczema was 1.4, 1.9 and 10.0%, respectively. We estimated OR for lifetime hand eczema in smelter workers to 4.36 [95% CI: 1.31–14.43, p = 0.016] and for lifetime skin complaints in other locations to 2.25 [95% CI: 0.98–5.18, p = 0.058]. The lifetime prevalence of skin complaints at other locations was 18.9, 23.1 and 40.0%, respectively. The point prevalence was 14.9, 9.6 and 16.7%, respectively. These estimates were not statistically significant but indicates that smelter workers have more skin complaints also at other locations. Conclusion: This study reports a more than four-fold increased risk of hand eczema in smelter workers, and possibly a higher risk of skin complaints in other body locations, compared to the other occupations. Longitudinal studies with larger population are needed to verify the marked increased risk of eczema among smelters and establish causation. [ABSTRACT FROM AUTHOR]

The ongoing anthropogenic pollution of the biosphere with As, Cd, Hg and Pb will inevitably result in an increased influx of their corresponding toxic metal(loid) species into the bloodstream of human populations, including children and pregnant women. To delineate whether the measurable concentrations of these inorganic pollutants in the bloodstream are tolerable or implicated in the onset of environmental diseases urgently requires new insight into their dynamic bioinorganic chemistry in the bloodstream–organ system. Owing to the human exposure to multiple toxic metal(loid) species, the mechanism of chronic toxicity of each of these needs to be integrated into a framework to better define the underlying exposure–disease relationship. Accordingly, this review highlights some recent advances into the bioinorganic chemistry of the Cd2+, Hg2+ and CH3Hg+ in blood plasma, red blood cells and target organs and provides a first glimpse of their emerging mechanisms of chronic toxicity. Although many important knowledge gaps remain, it is essential to design experiments with the intent of refining these mechanisms to eventually establish a framework that may allow us to causally link the cumulative exposure of human populations to multiple toxic metal(loid) species with environmental diseases of unknown etiology that do not appear to have a genetic origin. Thus, researchers from a variety of scientific disciplines need to contribute to this interdisciplinary effort to rationally address this public health threat which may require the implementation of stronger regulatory requirements to improve planetary and human health, which are fundamentally intertwined. [ABSTRACT FROM AUTHOR]

This article discusses the design and analysis of a new chemical chemosensor for detecting mercury(II) ions. The chemosensor is a hydrazone made from 4-methylthiazole-5-carbaldehyde and fluorescein hydrazide. The structure of the chemosensor was confirmed using various methods, including nuclear magnetic resonance spectroscopy, infrared spectroscopy with Fourier transformation, mass spectroscopy, and quantum chemical calculations. The sensor's ability in the highly selective and sensitive discovery of Hg2+ ions in water was demonstrated. The detection limit for mercury(II) ions was determined to be 0.23 µM. The new chemosensor was also used to detect Hg2+ ions in real samples and living cells using fluorescence spectroscopy. Chemosensor 1 and its complex with Hg2+ demonstrate a significant tendency to enter and accumulate in cells even at very low concentrations. [ABSTRACT FROM AUTHOR]

Cosmetic products are chemical substances or mixtures used on the skin, hair, nails, teeth, and the mucous membranes of the oral cavity, whose use is intended to clean, protect, correct body odor, perfume, keep in good condition, or change appearance. The analysis of cosmetic ingredients is often challenging because of their huge complexity and their adulteration. Among various analytical tools, mass spectrometry (MS) has been largely used for compound detection, ingredient screening, quality control, detection of product authenticity, and health risk evaluation. This work is focused on the MS applications in detecting and quantification of some common cosmetic ingredients, i.e., preservatives, dyes, heavy metals, allergens, and bioconjugates in various matrices (leave-on or rinse-off cosmetic products). As a global view, MS-based analysis of bioconjugates is a narrow field, and LC- and GC/GC×GC-MS are widely used for the investigation of preservatives, dyes, and fragrances, while inductively coupled plasma (ICP)-MS is ideal for comprehensive analysis of heavy metals. Ambient ionization approaches and advanced separation methods (i.e., convergence chromatography (UPC2)) coupled to MS have been proven to be an excellent choice for the analysis of scented allergens. At the same time, the current paper explores the challenges of MS-based analysis for cosmetic safety studies. [ABSTRACT FROM AUTHOR]

The global environmental issue of soil contamination with antibiotic-resistance genes has garnered increased attention in recent years due to its impact on ecosystems and human health. Despite this recognition, researchers face challenges in comprehensively understanding the mechanisms underlying the production and dissemination of soil resistance genes, particularly in relation to their implications for human health. This lack of understanding poses a barrier to the development of effective and precise control strategies. Biochar, a sustainable material, exhibits favorable adsorption properties characterized by its large pores and specific surface area. Therefore, we propose to explore the potential application of biochar addition in soil resistance gene management. In order to establish a solid research foundation in this area, in this paper we review the mechanisms underlying the generation and accumulation of soil resistance genes over the last decade, along with their transmission pathways and interfacial interactions. Biochar may help repair soil resistance genes by affecting factors like antibiotic levels, environmental conditions, enzymatic activity, and gene migration mechanisms, opening up new research possibilities. Highlights: The sources, transmission routes and effects on human health of soil ARGs are summarized, and the mechanism of soil ARGs control by biochar is discussed on the basis of the positive effects by biochar. The ways in which biochar affects soil ARGs are analyzed in several directions (soil physicochemical properties, heavy metal content, antibiotic content, microbial structure and enzyme activity) in an attempt to provide a basis for the next studies. The mechanisms of biochar in the regulation of antibiotics and heavy metals for soil ARGs removal are systematically and comprehensively described, while also prospecting the potential application of biochar in soil ARGs removal. [ABSTRACT FROM AUTHOR]

Background: The main challenge for large-scale production of bacterial cellulose (BC) includes high production costs interlinked with raw materials, and low production rates. The valorization of renewable nutrient sources could improve the economic effectiveness of BC fermentation while their direct bioconversion into sustainable biopolymers addresses environmental pollution and/or resource depletion challenges. Herein a green bioprocess was developed to produce BC in high amounts with the rather unexplored bacterial strain Komagataeibacter rhaeticus, using waste streams such as wine distillery effluents (WDE) and biodiesel-derived glycerol. Also, BC was evaluated as a bio-adsorbent for phenolics, dyes and metals removal to enlarge its market diversification. Results: BC production was significantly affected by the WDE mixing ratio (0–100%), glycerol concentration (20–45 g/L), type of glycerol and media-sterilization method. A maximum BC concentration of 9.0 g/L, with a productivity of 0.90 g/L/day and a water holding capacity of 60.1 g water/g dry BC, was achieved at 100% WDE and ≈30 g/L crude glycerol. BC samples showed typical cellulose vibration bands and average fiber diameters between 37.2 and 89.6 nm. The BC capacity to dephenolize WDE and adsorb phenolics during fermentation reached respectively, up to 50.7% and 26.96 mg gallic acid equivalents/g dry BC (in-situ process). The produced BC was also investigated for dye and metal removal. The highest removal of dye acid yellow 17 (54.3%) was recorded when 5% of BC was applied as the bio-adsorbent. Experiments performed in a multi-metal synthetic wastewater showed that BC could remove up to 96% of Zn and 97% of Cd. Conclusions: This work demonstrated a low-carbon approach to produce low-cost, green and biodegradable BC-based bio-adsorbents, without any chemical modification. Their potential in wastewater-treatment-applications was highlighted, promoting closed-loop systems within the circular economy era. This study may serve as an orientation for future research towards competitive or targeted adsorption technologies for wastewater treatment or resources recovery. [ABSTRACT FROM AUTHOR]

Recent progress in the development of MnO2-based micromotors has shown the immense potential of these motile devices to remediate environmental contamination. However, the production of such micromotors on an industrial scale through a facile, efficient and reproducible process remains challenging. The present work aimed to address this issue using naturally occurring and abundant pine pollen (PP) grains. The immersion of PP in potassium permanganate (KMnO4) solutions was found to generate MnO2 nanoparticles (NPs) on the PP surfaces, the amount and distribution of which was readily adjusted by varying the coating time. Because of the asymmetrical shape of the PP grains, the MnO2/PP composites exhibited rapid self-propulsion at a maximum speed of 360.686 μm/s (approximately eight body lengths/s) in low-concentration hydrogen peroxide (H2O2) solutions. The ability of these materials to remediate heavy metal pollutants was also examined and was evidently increased by a factor of 1.5 compared with static counterparts. These composites could also be recovered and reused over three consecutive cycles. The competitive cost, continuous motion and superior decontamination capacity of these materials suggests potential applications in the rapid removal or degradation of heavy metal ions, toxic organic dyes, pathogenic bacteria and other pollutants in wastewater. These micromotors represent a new approach to the utilization of natural materials in environmental remediation. [ABSTRACT FROM AUTHOR]

The monitoring of essential and toxic elements in patients with Opioid Use Disorder (OUD) undergoing methadone treatment (MT) is important, and there is limited previous research on the urinary levels of these elements in MT patients. Therefore, the present study aimed to analyze certain elements in the context of methadone treatment compared to a healthy group. In this study, patients with opioid use disorder undergoing MT (n = 67) were compared with a healthy group of companions (n = 62) in terms of urinary concentrations of some essential elements (selenium (Se), zinc (Zn), copper (Cu), iron (Fe), manganese (Mn), calcium (Ca)) and toxic elements (lead (Pb), cadmium (Cd), arsenic (As), and chromium (Cr)). Urine samples were prepared using the acid digestion method with a mixture of nitric acid and perchloric acid and assessed using the ICP-MS method. Our results showed that the two groups had no significant differences in terms of gender, education level, occupation, and smoking status. Urinary concentrations of Se, Cu, and Fe levels were significantly lower in the MT group compared to the healthy subjects. However, the concentrations of Pb, Cd, As, Mn, Cr, and Ca in the MT group were higher than in the healthy group (p < 0.05). No significant difference was established between the levels of Zn in the two groups (p = 0.232). The results of regression analysis revealed that the differences between the concentration levels of all metals (except Zn) between two groups were still remained significant after adjusting for all variables (p < 0.05). The data obtained in the current study showed lower urinary concentrations of some essential elements and higher levels of some toxic elements in the MT group compared to the healthy subjects. These findings should be incorporated into harm-reduction interventions. [ABSTRACT FROM AUTHOR]

Background: Copper-induced gene expression in Xanthomonas campestris pv. campestris (Xcc) is typically evaluated using targeted approaches involving qPCR. The global response to copper stress in Xcc and resistance to metal induced damage is not well understood. However, homologs of heavy metal efflux genes from the related Stenotrophomonas genus are found in Xanthomonas which suggests that metal related efflux may also be present. Methods and Results: Gene expression in Xcc strain BrA1 exposed to 0.8 mM CuSO4.5H2O for 15 minutes was captured using RNA-seq analysis. Changes in expression was noted for genes related to general stress responses and oxidoreductases, biofilm formation, protein folding chaperones, heat-shock proteins, membrane lipid profile, multiple drug and efflux (MDR) transporters, and DNA repair were documented. At this timepoint only the cohL (copper homeostasis/tolerance) gene was upregulated as well as a chromosomal czcCBA efflux operon. An additional screen up to 4 hrs using qPCR was conducted using a wider range of heavy metals. Target genes included a cop-containing heavy metal resistance island and putative metal efflux genes. Several efflux pumps, including a copper resistance associated homolog from S. maltophilia, were upregulated under toxic copper stress. However, these pumps were also upregulated in response to other toxic heavy metals. Additionally, the temporal expression of the coh and cop operons was also observed, demonstrating co-expression of tolerance responses and later activation of part of the cop operon. Conclusions: Overall, initial transcriptional responses focused on combating oxidative stress, mitigating protein damage and potentially increasing resistance to heavy metals and other biocides. A putative copper responsive efflux gene and others which might play a role in broader heavy metal resistance were also identified. Furthermore, the expression patterns of the cop operon in conjunction with other copper responsive genes allowed for a better understanding of the fate of copper ions in Xanthomonas. This work provides useful evidence for further evaluating MDR and other efflux pumps in metal-specific homeostasis and tolerance phenotypes in the Xanthomonas genus. Furthermore, non-canonical copper tolerance and resistance efflux pumps were potentially identified. These findings have implications for interpreting MIC differences among strains with homologous copLAB resistance genes, understanding survival under copper stress, and resistance in disease management. [ABSTRACT FROM AUTHOR]

The primary factors that restrict agricultural productivity and jeopardize human and food safety are heavy metals (HMs), including arsenic, cadmium, lead, and aluminum, which adversely impact crop yields and quality. Plants, in their adaptability, proactively engage in a multitude of intricate processes to counteract the impacts of HM toxicity. These processes orchestrate profound transformations at biomolecular levels, showing the plant's ability to adapt and thrive in adversity. In the past few decades, HM stress tolerance in crops has been successfully addressed through a combination of traditional breeding techniques, cutting-edge genetic engineering methods, and the strategic implementation of marker-dependent breeding approaches. Given the remarkable progress achieved in this domain, it has become imperative to adopt integrated methods that mitigate potential risks and impacts arising from environmental contamination on yields, which is crucial as we endeavor to forge ahead with the establishment of enduring agricultural systems. In this manner, nanotechnology has emerged as a viable field in agricultural sciences. The potential applications are extensive, encompassing the regulation of environmental stressors like toxic metals, improving the efficiency of nutrient consumption and alleviating climate change effects. Integrating nanotechnology and nanomaterials in agrochemicals has successfully mitigated the drawbacks associated with traditional agrochemicals, including challenges like organic solvent pollution, susceptibility to photolysis, and restricted bioavailability. Numerous studies clearly show the immense potential of nanomaterials and nanofertilizers in tackling the acute crisis of HM toxicity in crop production. This review seeks to delve into using NPs as agrochemicals to effectively mitigate HM toxicity and enhance crop resilience, thereby fostering an environmentally friendly and economically viable approach toward sustainable agricultural advancement in the foreseeable future. [ABSTRACT FROM AUTHOR]

Phytoremediation is a cost-effective and environmentally friendly method, offering a suitable alternative to chemical and physical approaches for the removal of pollutants from soil. This research explored the phytoremediation potential of Alhagi camelorum, a plant species, for total petroleum hydrocarbons (TPHs) and heavy metals (HMs), specifically lead (Pb), chromium (Cr), nickel (Ni), and cadmium (Cd), in oil-contaminated soil. A field-scale study spanning six months was conducted, involving the cultivation of A. camelorum seeds in a nursery and subsequent transplantation of seedlings onto prepared soil plots. Control plots, devoid of any plants, were also incorporated for comparison. Soil samples were analyzed throughout the study period using inductively coupled plasma-optical emission spectroscopy (ICP‒OES) for HMs and gas chromatography‒mass spectrometry (GC‒MS) for TPHs. The results showed that after six months, the average removal percentage was 53.6 ± 2.8% for TPHs and varying percentages observed for the HMs (Pb: 50 ± 2.1%, Cr: 47.6 ± 2.5%, Ni: 48.1 ± 1.6%, and Cd: 45.4 ± 3.5%). The upward trajectory in the population of heterotrophic bacteria and the level of microbial respiration, in contrast to the control plots, suggests that the presence of the plant plays a significant role in promoting soil microbial growth (P < 0.05). Moreover, kinetic rate models were examined to assess the rate of pollutant removal. The coefficient of determination consistently aligned with the first-order kinetic rate model for all the mentioned pollutants (R2 > 0.8). These results collectively suggest that phytoremediation employing A. camelorum can effectively reduce pollutants in oil-contaminated soils. [ABSTRACT FROM AUTHOR]

This article presents the results of field research, as well as the results of the use of remote-sensing data in the geochemical study of the soil cover of the Yertis River basin. In the work, the content of the gross form of heavy metals in the soil of the river basin was investigated. The atomic absorption method determined the content of the Poor configuration of elements of elements in soils. Statistical processing of the obtained data from N. A. Plokhinsky was carried out using the Statistica program. Also, using the performed indices in the remote sensing of clay minerals, iron oxides, and carbonates, the spatial distribution and comparison of pollutants in the soil cover of the river basin were revealed. The methods and means of image processing tested in this study can be used to create maps of the distribution of pollutants. Also, the data obtained reflect the patterns of distribution of heavy metals in the soils of the basin and can be used to optimize landscapes and improve the organization of ecological and geochemical monitoring. [ABSTRACT FROM AUTHOR]

The magnetic states of antiferromagnetic insulating thin films are a promising medium for information storage, but characterization of these states has proven to be challenging. One approach is via magnetotransport measurements in an adjacent heavy metal layer. To this end, we synthesized and characterized a series of Cr2O3 films and bilayers on Al2O3 substrates with three different orientations: m-plane, a-plane, and c-plane. X-ray diffraction results demonstrated orientation control of the Cr2O3 thin film, with m-plane films displaying a higher degree of mosaic spread than the a- and c-plane films. Reciprocal space maps showed that the films are mostly relaxed, although there was a small and different degree of strain in each orientation. The m-plane films were under 2% compressive strain, the a-plane film was under 0.5% compressive strain, and the c-plane film was completely relaxed to bulk values. To probe the magnetic state of the films, we measured the angular dependent magnetoresistance of Cr2O3/Pt bilayers for each orientation. We found a nontrivial temperature dependence of the sign of the magnetoresistance, pointing to the complex interplay between the exchange and anisotropy energies that vary with orientation. We propose that strain and mosaic spread may contribute to a difference in magnetic anisotropies among the samples and the resulting temperature dependence of the magnetoresistance. This work demonstrates the importance of considering the competition between antiferromagnetic exchange and magnetic anisotropy when storing information in the spin state of an antiferromagnetic insulator. [ABSTRACT FROM AUTHOR]

The heavy metal content of Pb, Zn, and Ni in soil, nettle plants (rhizomes, stems, and leaves), and snail shells was investigated in this study. Samples were collected during the summer-autumn period of 2020 from the vicinity of the TC Kosova A power plant in Obiliq (Prishtina), Kosovo, and compared to samples from the control site, Brezne-Opoja. Soil samples were dried at 105°C for 48 hours and treated with a mixture of 69% HNO3 and HClcc in a 1:3 ratio. Similarly, biota samples were dried at 105°C for 48 hours and treated with a mixture of 69% HNO3 and H2O2cc in a 1:3 ratio. All sample types were digested in the microwave at 200°C for 45 minutes and analyzed using a flame type absorber (Analyticyena Contra AAA). The results indicate significantly higher concentrations of Pb, Ni, and Zn in the Obiliq area compared to Opoja, in both soil and biota (nettle and snail shells), suggesting potential environmental impact from the nearby coal-burning plant, heavy traffic, or other urban services. The average values generally fell below the limits specified by the UK (1989) or Germany (1992) standards (Directive 2008/50/EC). However, the Zn content in all soil samples exceeded the German standard. Pb and Zn were found to be extensively absorbed by nettle plants (U. dioica) and garden snails (H. pomatia), whereas Ni showed no significant bioaccumulation in either species, despite its high concentration in the soil. Nettle plants exhibited heavy bioaccumulation of Pb, reaching levels up to 105.6 mg/kg dw, surpassing the German standard limit. Nettle plants show promise in the phytoremediation and soil amendment processes for heavy metal pollution, particularly for Pb and Zn, but not for Ni. Garden snails can serve as bioindicators for assessing heavy metal pollution and its impact on transfer processes within the food chain, as well as the resulting effects on biochemical and physiological processes in living organisms, specifically in relation to oxidative stress. The contamination of soil and biota with heavy metals in the Obiliq area should be regarded as a significant concern. Therefore, regular monitoring of heavy metal content in agricultural, garden, livestock, and poultry activities is necessary to mitigate the associated health risks to humans. [ABSTRACT FROM AUTHOR]

For the first time, composites of metal-organic framework MOF-5 and conjugated polymer polyaniline (PANI), (MOF-5/PANI), prepared using PANI in its conducting (emeraldine salt, ES) or nonconducting form (emeraldine base, EB) at various MOF-5 and PANI mass ratios, were evaluated as electrode materials for the electrochemical detection of cadmium (Cd2+) and lead (Pb2+) ions in aqueous solutions. Testing of individual components of composites, PANI-ES, PANI-EB, and MOF-5, was also performed for comparison. Materials are characterized by Raman spectroscopy, scanning electron microscopy (SEM) and dynamic light scattering (DLS), and their electrochemical behavior was discussed in terms of their zeta potential, structural, morphology, and textural properties. All examined composites showed high electrocatalytic activity for the oxidation of Cd and Pb to Cd2+ and Pb2+, respectively. The MOF/EB-1 composite (71.0 wt.% MOF-5) gave the highest oxidation currents during both individual and simultaneous detection of two heavy metal ions. Current densities recorded with MOF/EB-1 were also higher than those of its individual components, reflecting the synergistic effect where MOF-5 offers high surface area for two heavy metals adsorption and PANI offers a network for electron transfer during metals' subsequent oxidation. Limits of detection using MOF/EB-1 electrode for Cd2+ and Pb2+ sensing were found to be as low as 0.077 ppm and 0.033 ppm, respectively. Moreover, the well-defined and intense peaks of Cd oxidation to Cd2+ and somewhat lower peaks of Pb oxidation to Pb2+ were observed at voltammograms obtained for the Danube River as a real sample with no pretreatment, which implies that herein tested MOF-5/PANI electrodes could be used as electrochemical sensors for the detection of heavy metal ions in the real water samples. [ABSTRACT FROM AUTHOR]

Background: Minimizing the risk of heavy metal pollution is of utmost importance to ensure consumer safety. In this research, we utilized inductively coupled plasma‐mass spectrometry to determine the presence of 12 heavy metals in Taiwanese commercial edible oils, both refined and unrefined. Results: Our analytical findings revealed significantly lower levels of heavy metals in refined oils compared with unrefined oils. Through principal component analysis and cluster analysis of 19 types of edible oils, we identified Cd, Ba, Fe, Pb, and Co as the primary variables influencing heavy metal levels in edible oils. Notably, the heavy metal contents in the edible oils did not surpass international standards. Risk assessment results indicated that unrefined oils carried higher risk levels than refined oils. The incremental lifetime cancer risk values calculated for unrefined oils exceeded 10−6 in all age groups except for the 19 ~ 65 years category, while the noncarcinogenic risks remained well below 1, regardless of refined or unrefined oils. Conclusions: Our study sheds light on the distribution characteristics of heavy metal contents in edible oils, highlighting higher levels of heavy metals and associated risks in non‐refined oils compared with refined oils. Ultimately, the presence of heavy metals in edible oils poses low health risks to the human body. [ABSTRACT FROM AUTHOR]

The high salt in seawater samples brings great challenges for analyzing trace heavy metals. To achieve the green separation and rapid detection of trace lead and copper in seawater, a method of coconut shell biochar enrichment was established. By using the method of adsorption and desorption, lead and copper elements in seawater were enriched on coconut shell biochar, and the coconut shell biochar powder was repeatedly washed with pure water to remove the salt matrix in seawater. The desorption was dissolved with 7.5% HNO3, and the desorption solution was filtered with 0.45μm filter membranes and analyzed by ICP-MS. Two metal elements showed good linear relationships within the range of 0.10−100μg/L, and the linear correlation coefficients were greater than 0.9995. The method had a detection limit of 0.005μg/L for Pb and 0.006μg/L for Cu, meeting the evaluation requirements of seawater quality assessment stipulated in Technical Specification for Assessment of Sea Water, Marine Sediment and Marine Biological Quality (HJ1300—2023). The spiked recovery rates for seawater samples were between 96.1% and 102.3%, with the relative standard deviation less than 5%. This method had the advantages of simple operation, low costs, environmental protection, and high reliability and sensitivity [ABSTRACT FROM AUTHOR]

Lake Nasser is a freshwater lake that supplies over 95% of Egypt's freshwater budget. Therefore, the quality of water in the lake is critical for its conservation. In addition to assessing the metal pollution load, the quality of water and sediment in the lake was assessed by collecting water and sediment samples for metal content analysis. Lake Nasser is a warm monomictic water body with a single circulation cycle in the cold months. Dissolved oxygen content in bottom water samples often dropped significantly to levels below international guidelines, reflecting reduced rates of photosynthetic activity. Although 50% of the lake's water samples contained Pb concentrations slightly above the World Health Organization's (WHO) limit for drinking water, the metal pollution index did not exceed the critical level and was classified as low metal water pollution. Based on the geoaccumulation index (I-geo), the enrichment factor (EF) and the pollution load index, the sediments of Lake Nasser are practically uncontaminated with metals. Ni has the highest EF and I-geo values, while Ni and Cd contributed the most to the ecological risk and toxic risk index. The obtained results revealed that Cd and Ni in the sediments may pose a threat to organisms living in Lake Nasser. [ABSTRACT FROM AUTHOR]

This study investigates the concentrations and spatial distribution of toxic heavy metals (Cd, Cu, Pb and Zn) through chemical analysis of rainwater samples collected in Tehran, Iran during winter and spring of 2022, characterized by different land use, emission sources, traffic conditions and population density. The average concentrations of the examined heavy metals at the five sampling sites were 52.9, 11.8, 14.6 and 0.93 μg l−1 for Zn, Pb, Cu and Cd, respectively. The concentrations of all heavy metals were significantly higher (p < 0.05) at the sampling points in central and south Tehran compared to sites in the west and north, due to different urban characteristics, higher pollution emission rates from the traffic and domestic sectors, and local wind patterns developed within the city. High traffic load in the central part of Tehran also escalates the heavy metal concentrations in this region. The significant correlations between the examined heavy metals at the five sites indicate common, local anthropogenic sources. The heavy metal concentrations were higher for rain samples collected in spring than in winter, likely associated with dilution processes in winter and the restriction measures due to COVID-19 pandemic. During the lockdown period, a drastic decrease in traffic load was observed in Tehran, confirming that motor vehicles is the main regulatory factor for air pollution and potential toxic elements in the city. [ABSTRACT FROM AUTHOR]

The rapid growth of industrialization has led to the uncontrolled pollution of the environment, and rapid action is needed. This study synthesized Ag/TiO2/polyvinyl alcohol (PVA) nano photocatalyst for promising light-derived photocatalytic removal of heavy metal ions. The design of experiment (DOE) was used to study the effect of important factors (pH, reaction time, and photocatalyst dosage) to maximize the final performance of the photocatalyst. In the optimized condition, the Ag/TiO2/PVA nano-photocatalyst removed more than 94% of Cr6+ in 180 min, and the efficiency was more than 70% for Cu2+, Zn2+, and Ni2+ metal ions. The adsorption of the heavy metal ions on the photocatalyst was described well with the Langmuir isotherm, while the pseudo-second-order linear kinetic model fitted with the experimental data. The nano-photocatalyst's stability was confirmed after maintaining its performance for five successive runs. The enhanced photocatalytic activity for the heavy metal ions removal can be attributed to the presence of metallic silver nanoparticles (electron transfer and plasmonic fields mechanisms) and PVA, which delayed the recombination of electron–hole. The synthesized ternary Ag/TiO2/PVA nano-photocatalyst showed promising performance for the elimination of heavy metal ions and can be used for environmental remediation purposes. [ABSTRACT FROM AUTHOR]

The luminescent spectra of the RE2O3-doped P2O5–CdO–ZnO glasses (RE = Er, and Tb) were investigated to separate the effects of two studied rare-earth elements and the annealing regime on the emission performance of the prepared glasses. The glasses undergo a series of collective measurements including UV–visible absorption, luminescence, thermal expansion, XRD, TEM, and FTIR. The optical UV–visible spectra of the two doped glasses reveal a UV band due to undoped glass beside and extra extended 11 peaks with the Er3+ ions with high distinct features while the Tb3+ ions samples exhibit peaks within the visible region. These peaks are correlated with transitions from the ground state in each case to specific energy transitions. The overall optical data indicate that the two rare earth ions are present in a stable trivalent state. Under UV excitation, both Er3+ and Tb3+ emit a characteristic green light corresponding to 4S3/2 → 4I15/2 and 5D4 → 7F5 transitions, respectively. The performance of the green light was identified to be enhanced by increasing the concentration of rare earth and the effect of annealing temperature. Moreover, the intensity of the infrared emission of Er3+ at 1532 nm corresponds to the (4I13/2 → 4I15/2) transition which is assumed to be developed with the effect of heating. The resultant IR spectra show distinct vibrational peaks due to phosphate groups that undergo only minor modifications when doped with rare earth elements or over-annealed. [ABSTRACT FROM AUTHOR]

This study aimed to assess the value of Pachira aquatica Aubl. fruit peels by exploring their applicability in the biosorption process for the removal of Ni(II) and Cd(II) metal ions. The Pachira aquatica Aubl. fruit peel biochar (PAB) was extensively characterized through various techniques, including proximate analysis, helium pycnometer, XRD, SEM, point of zero charge determination, zeta potential measurement, and Boehm titration. Subsequently, kinetic, isotherm, and thermodynamic batch biosorption studies were conducted, followed by column biosorption tests. The characteristics of PAB, including low moisture content, a neutral point of zero charge, porosity, an irregular and heterogeneous structure, a negatively charged surface, and the presence of functional groups, indicate its remarkable capacity for efficiently binding with heavy metals. Biosorption equilibrium time was achieved at 300 min for both ions, fitting well with a pseudo second-order kinetic model and Langmuir isotherm model. These data suggest that the biosorption process occurred chemically in monolayer. The column C presented an exhaust volume of 1200 mL for Ni(II) and 1080 for Cd(II) and removal of 98% and 99% of removal for Ni(II) and Cd(II), respectively. In summary, PAB demonstrates substantial potential as a biosorbent for effectively removing heavy metals, making a valuable contribution to the valorization of this co-product and the mitigation of environmental pollution. [ABSTRACT FROM AUTHOR]

Acid mine drainage (AMD) is a major environmental problem caused by the release of acidic, toxic, and sulfate-rich water from mining sites. This study aimed to develop novel adsorbents for the removal of chromium (Cr(VI)), cadmium (Cd(II)), and lead (Pb(II)) from simulated and actual AMD using hybrid ion-exchange resins embedded with hydrous ferric oxide (HFO). Two types of resins were synthesized: anionic exchange resin (HAIX-HFO) for Cr(VI) removal and cationic exchange resin (HCIX-HFO) for Cd(II) and Pb(II) removal. The resins were characterized using scanning electron microscopy and Raman spectroscopy, which confirmed the presence of HFO particles. Batch adsorption experiments were conducted under acidic and sulfate-enhanced conditions to evaluate the adsorption capacity and kinetics of the resins. It was found that both resins exhibited high adsorption efficiencies and fast adsorption rates for their respective metal ions. To explore the potential adsorption on actual AMD, HCIX-HFO demonstrated significant removal of some metal ions. The saturated HCIX-HFO resin was regenerated using NaCl, and a high amount of the adsorbed Cd(II) and Pb(II) was recovered. This study demonstrates that HFO-embedded hybrid ion-exchange resins are promising adsorbents for treating AMD contaminated with heavy metals. [ABSTRACT FROM AUTHOR]

This article explores recent advancements and innovative strategies in biosorption technology, with a particular focus on the removal of heavy metals, such as Cu(II), Pb(II), Cr(III), Cr(VI), Zn(II), and Ni(II), and a metalloid, As(V), from various sources. Detailed information on biosorbents, including their composition, structure, and performance metrics in heavy metal sorption, is presented. Specific attention is given to the numerical values of the adsorption capacities for each metal, showcasing the efficacy of biosorbents in removing Cu (up to 96.4%), Pb (up to 95%), Cr (up to 99.9%), Zn (up to 99%), Ni (up to 93.8%), and As (up to 92.9%) from wastewater and industrial effluents. In addition, the issue of biosorbent deactivation and failure over time is highlighted as it is crucial for the successful implementation of adsorption in practical applications. Such phenomena as blockage by other cations or chemical decomposition are reported, and chemical, thermal, and microwave treatments are indicated as effective regeneration techniques. Ongoing research should focus on the development of more resilient biosorbent materials, optimizing regeneration techniques, and exploring innovative approaches to improve the long-term performance and sustainability of biosorption technologies. The analysis showed that biosorption emerges as a promising strategy for alleviating pollutants in wastewater and industrial effluents, offering a sustainable and environmentally friendly approach to addressing water pollution challenges. [ABSTRACT FROM AUTHOR]

With the paramount development of industry and agriculture sector, levels of different pollutants like, heavy metal ions, pharmaceuticals, organic dyes, biological waste and other pollutants are becoming serious. The ecosystem and human health suffered greatly from the adverse effects of these pollutants. The disposal of these pollutants has become an urgent issue for the human society. Graphene oxide base nanocomposites have generated an excellent extent of focus as desirable alternatives for the adsorptive elimination of contaminants from aqueous systems owing to their enhanced surface area and multiple functional groups for adsorption. Graphene oxide (GO) as a graphene derivative exhibited superior features as obtainable in a graphene sheet. Moreover, the addition of oxygen functional group at the edges and basal plane of graphene further enhanced the efficiency of the graphene by providing sites for the attachment of different metals on the surface. On the underlying adsorption processes, graphene-based nanocomposites for specific contaminants are designed and currently employed for wastewater treatment. This review presents the ongoing development of GO base nanocomposites and their useful applications, understanding how well graphene-based nanocomposites adsorb pollutants and how that relates to the ways in which pollutants interact with adsorbents is crucial. This study highlights newly developed trends in the creation of graphene oxide based nanocomposites to eliminate different heavy metal ions, dyes, pharmaceuticals, and oils spills from effluent water. The focus is on various graphene oxides nanocomposites application for the removal of different pollutants and regeneration of graphene oxide base nanocomposites after several adsorption cycles. Other challenges and potential directions for designing efficient GO based nanocomposites as adsorbents are also presented along with the problems of current studies. [ABSTRACT FROM AUTHOR]

In the study of the inversion of soil multi-species heavy metal element concentrations using hyperspectral techniques, the selection of feature bands is very important. However, interactions among soil elements can lead to redundancy and instability of spectral features. In this study, heavy metal elements (Pb, Zn, Mn, and As) in entisols around a mining area in Harbin, Heilongjiang Province, China, were studied. To optimise the combination of spectral indices and their weights, radar plots of characteristic-band Pearson coefficients (RCBP) were used to screen three-band spectral index combinations of Pb, Zn, Mn, and As elements, while the Catboost algorithm was used to invert the concentrations of each element. The correlations of Fe with the four heavy metals were analysed from both concentration and characteristic band perspectives, while the effect of spectral inversion was further evaluated via spatial analysis. It was found that the regression model for the inversion of the Zn elemental concentration based on the optimised spectral index combinations had the best fit, with R2 = 0.8786 for the test set, followed by Mn (R2 = 0.8576), As (R2 = 0.7916), and Pb (R2 = 0.6022). As far as the characteristic bands are concerned, the best correlations of Fe with the Pb, Zn, Mn and As elements were 0.837, 0.711, 0.542 and 0.303, respectively. The spatial distribution and correlation of the spectral inversion concentrations of the As and Mn elements with the measured concentrations were consistent, and there were some differences in the results for Zn and Pb. Therefore, hyperspectral techniques and analysis of Fe elements have potential applications in the inversion of entisols heavy metal concentrations and can improve the quality monitoring efficiency of these soils. [ABSTRACT FROM AUTHOR]

Pollutants in an environment can have long-term implications for the species living there, resulting in local adaptations with implications for their genetic structure. Heavy metal pollutants infiltrate soils and groundwater, bioaccumulate in food webs, and negatively impact biota. In this study, we investigated the degree to which the genetic structure and variability of the slender green-winged grasshopper (Aiolopus thalassinus (Fabricius) (Orthoptera: Acrididae)) were impacted by heavy metal pollution and distance. We used the random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) method to examine the genetic variability of populations in 3 heavy metal-polluted and 3 unpolluted locations across varying geographical distances in Egypt. The heavy metal concentrations of cadmium, copper, lead, and zinc were measured from the grasshopper tissue and soils. Sixty-nine unique and polymorphic bands were produced by 4 primers. Cluster and principal component analyses separated the populations inside and outside Cairo into 2 main branches, which were further divided into smaller branches corresponding to their geographical regions. We found no differences in the Shannon genetic diversity index between populations or with increasing heavy metal concentrations in either the soil or the grasshopper tissue. Our results showed a greater genetic variation among populations than between populations within the same location, indicating populations within locations were less differentiated than those between locations. The moderate correlation between genetic similarity and spatial distance suggests geographical isolation influenced grasshopper population differentiation. Based on the RAPD analysis, environmental pollutants and geographical distances impact the A. thalassinus population structure, potentially restricting gene flow between sites even at small spatial scales. [ABSTRACT FROM AUTHOR]

Approximately 95% of urban solid waste worldwide is disposed of in landfills. About 14 million metric tonnes of this municipal solid waste are disposed of in landfills every year in Malaysia, illustrating the importance of landfills. Landfill leachate is a liquid that is generated when precipitation percolates through waste disposed of in a landfill. High concentrations of heavy metal(loid)s, organic matter that has been dissolved and/or suspended, and inorganic substances, including phosphorus, ammonium, and sulphate, are present in landfill leachate. Globally, there is an urgent need for efficient remediation strategies for leachate-metal-contaminated soils. The present study expatiates on the physicochemical conditions and heavy metal(loid)s' concentrations present in leachate samples obtained from four landfills in Malaysia, namely, Air Hitam Sanitary Landfill, Jeram Sanitary landfill, Bukit Beruntung landfill, and Taman Beringin Landfill, and explores bioaugmentation for the remediation of leachate-metal-contaminated soil. Leachate samples (replicates) were taken from all four landfills. Heavy metal(loids) in the collected leachate samples were quantified using inductively coupled plasma mass spectrometry. The microbial strains used for bioaugmentation were isolated from the soil sample collected from Taman Beringin Landfill. X-ray fluorescence spectrometry was used to analyze heavy metal(loid)s in the soil, prior to the isolation of microbes. The results of the present study show that the treatments inoculated with the isolated bacteria had greater potential for bioremediation than the control experiment. Of the nine isolated microbial strains, the treatment regimen involving only three strains (all Gram-positive bacteria) exhibited the highest removal efficiency for heavy metal(loid)s, as observed from most of the results. With regard to new findings, a significant outcome from the present study is that selectively blended microbial species are more effective in the remediation of leachate-metal-contaminated soil, in comparison to a treatment containing a higher number of microbial species and therefore increased diversity. Although the leachate and soil samples were collected from Malaysia, there is a global appeal for the bioremediation strategy applied in this study. [ABSTRACT FROM AUTHOR]

Nickel (Ni) is extremely toxic to plants at high concentrations. Phytoliths have the potential to sequester the heavy metals absorbed by plants and act as a detoxification mechanism for the plant. The authors of the present study aimed to evaluate the effects of Ni on the growth and phytolith yield of grasses in two artificially contaminated soils. Two experiments separated by soil types (Typic Quartzipsamment and Rhodic Hapludox) were conducted in a completely randomized design in a 2 × 4 factorial scheme with three replications. The factors were two species of grass (Urochloa decumbens and Megathyrsus maximus) and three concentrations of Ni (20, 40, and 120 mg kg−1) and control treatment. The grasses were influenced by the increase in Ni rates in the soils. Ni exerted a micronutrient function with the addition of 30 mg kg−1 of Ni in soils, but this concentration caused toxicity in grasses. Such a level is lower than the limits imposed by the Brazilian environmental legislation. Higher Ni availability in Typic Quartzipsamment promoted Ni toxicity, with reduced growth and increased phytolith yield in the shoot, increased Ni in the shoot, and Ni occlusion in phytoliths by grasses, in comparison with Rhodic Hapludox. The yield and Ni capture in phytoliths by grasses in Ni-contaminated soils are related to the genetic and physiological differences between grasses and Ni availability in soils. Ni capture by phytoliths indicates that it may be one of the detoxification mechanisms of Urochloa decumbens to Ni contamination, providing additional tolerance. Megathyrsus maximus may be a future grass for the phytoremediation technique in Ni-contaminated soils. [ABSTRACT FROM AUTHOR]

The bioaccumulation of selenium (Se) and heavy metals (HMs) in plants is important because it can affect plant health and human nutrition. Recognizing the factors affecting Se accumulation in plants may have important implications for agricultural practices and human health in selenium-rich regions. The study primarily focused on the interactions between Se and HMs in the soil–plant system of the Lower Dniester Valley. Total concentrations of HMs (Cu, Mn, Zn) were determined by atomic absorption spectrometry, while Se concentrations were determined by a sensitive single-test-tube fluorometric method in solutions and extracts. Water-soluble Se (0.09 ± 0.03 mg·kg−1) in soils was 32.1% of the total Se (0.33 ± 0.13 mg·kg−1) and increased with the total rising Se content (r = 0.845). The results indicated that plants had a greater Zn accumulation capacity than that of the other HMs, suggesting its importance as a trace element for plant requirements. Se also had a high bioaccumulation rate. Se and Zn accumulation varied in different soil types, reflecting differences in bioavailability. In contrast, Mn and Cu showed low bioaccumulation, which varied with soil conditions and anthropogenic Cu pollution. Despite the Cu contamination of the soils in the investigated region, it can be inferred that the hydrogeochemical province with high Se content in groundwater has favorable conditions for Se mobilization in soils. The absence of antagonistic interactions with HMs in the soil–plant system contributes to the enhanced Se accumulation in plants in the Lower Dniester Valley. These results emphasize the complexity of the interactions between Se and HMs in the soil–plant system and their potential impact on agricultural practices. [ABSTRACT FROM AUTHOR]

Historical coal mining practices have caused various soil and water hazards, particularly through the dumping of mine waste. The primary environmental risk associated with this waste is the leaching of toxic metals from dumps of spoil or refuse into the subsurface soil or into nearby water resources. The extent of metal release is controlled via the oxidative dissolution of pyrite and potential re-sequestration through secondary Fe oxides. The characterization of the dominant Fe-bearing phase and the distribution of trace metals associated with these phases was determined via electron microscopy, synchrotron-based X-ray micro-fluorescence (μ-XRF) element and redox mapping from shallow mine soils from an impacted watershed in Appalachian Ohio. The dominant Fe-bearing phases were: (1) unweathered to partially weathered pyrite; (2) pseudomorphic replacement of pyrite with Fe(III) oxides; (3) fine-grained Fe oxide surface coatings; and (4) discrete Fe(III) oxide grains. Thicker secondary coatings and larger particles were sulfate rich, whereas smaller grains and thinner coatings were sulfate poor. The discrete Fe oxide grains exhibited the highest concentrations of Cr, Mn, Ni, and Cu, and sub-grain-scale concentration trends (Mn > Cr > Ni > Cu) were consistent with bulk soil properties. Predicting future metal transport requires an understanding of metal speciation and distribution from the sub-grain scale to the pedon scale. [ABSTRACT FROM AUTHOR]

This article discusses the importance of chemical separations in industrial manufacturing processes and their significant energy use in the United States. It focuses on the potential of electrochemical separations for applications such as critical minerals recovery, CO2 purification, and water desalination. The text highlights the role of electrode and electrolyte materials in achieving selective separations and mentions various strategies and materials used in electrochemical platforms. It also mentions the advantages of electrochemical separations, such as their potential to be powered by renewable energy and generate less chemical waste. The article provides a list of references from various scientific journals and publications, covering a wide range of topics and years, which can be useful for further research. [Extracted from the article]

In this study, we explored the effective capture of both cations and anions onto a single adsorbent. Acrylamide (AAm) served as the polymer backbone, onto which co-monomers sodium p-styrenesulfonate (SS) and N,N-dimethylaminopropyl acrylamide (DMAPAA) were grafted, creating ionized polymer hydrogel adsorbents. These adsorbents were engineered for the synergistic separation and recovery of heavy metal cations and anions from concentrated solutions, focusing specifically on industrially significant ions such as Ni2+-, Cu2+, Zn2+ and (Cr2O7)2-. The adsorption and desorption behaviors of the AAm terpolymer hydrogels were investigated across various pH solutions, considering the competition and concentrations of these specific metal ions. Moreover, the study delved into the effects of the internal pH environment within the hydrogel adsorbents, determining its impact on the type of metal adsorbed and the adsorption capacity. Our findings indicated that the adsorption of cations was enhanced with a higher proportion of SS relative to DMAPAA in the hydrogel. In contrast, significant anion capture occurred when the concentration of DMAPAA exceeded that of SS. However, equal ratios of SS and DMAPAA led to a noticeable reduction in the adsorption of both types of substrates, attributed to the counteractive nature of these co-monomers. To enhance the adsorption efficiency, it may be necessary to consider methods for micro-scale separation of the two types of monomers. Additionally, the adsorption capacity was observed to be directly proportional to the swelling capacity of the hydrogels. For complete desorption and separation of the cations and anions from the adsorbent, the application of concentrated NaOH solutions followed by HNO3 was found to be essential. Given the varying concentrations of cation and anion pollutants, often present in heavy metal factory effluents, it is crucial to fine-tune the ratios of DMAPAA and SS during the synthesis process. This adjustment ensures optimized efficiency in the decontamination and recovery of these significant heavy metal ions. [ABSTRACT FROM AUTHOR]

Pesticide residues and heavy metal content of cassava, yam, cocoyam, potato, water yam and carrot were evaluated by gas chromatography-mass spectrometry and atomic absorption spectroscopy. The detected pesticide residues in the samples were 2,4-dichlorophenoxyacetic acid, glyphosate, hexachlorobenzene (HCB), dichlorobiphenyl, aldrin, endosulfan, profenofos, g-chlordane, carbofuran, biphenyl, heptachlor, lindane and t-Nonachlor. The concentration of HCB ranged between 0.0799 ± 0.06 mg/kg and 0.1596 ± 0.00 mg/kg, which was greater than the permitted maximum limit of 0.5 mg/kg established by the US Environmental Protection Agency. The concentration of aldrin and profenofos detected was lower than the predetermined maximum allowed limits. Endosulfan concentrations in cocoyam (0.2500 mg/kg) and potato (0.3265 mg/kg) were higher than the limits allowed by the Canadian Department of Industrial Research. The heavy metals detected in these samples include cobalt, nickel, lead, manganese, chromium, arsenic and mercury in at least one of the samples evaluated. There was not much difference between the concentration of cobalt in yam (0.036 mg/kg) and the maximum allowed concentration (0.043 mg/kg). Lead was detected in potatoes and carrots but was below detectable concentration in cassava, yam, cocoyam and water yam. Similarly, cocoyam was found to have a significant mercury content (0.658 mg/kg), but mercury content was below detectable concentrations in cassava, yam and water yam. [ABSTRACT FROM AUTHOR]

High temperature corrosion of fuel cladding material (15-15Ti) in high burn-up situations has been an important topic for molten metal-cooled Gen-IV reactors. The present study aims to investigate the simultaneous impact of liquid lead (coolant side) and cesium molybdate (fuel side) on the cladding tube material. A capsule was designed and built for experiments between 600 °C and 1000 °C. In order to simulate a cladding breach scenario, a notch design on the cladding tube was investigated pre- and postexposure. Material thinning by corrosion and leaching at temperatures ≥ 900 °C caused breaches at the notches after 168 h exposure. The temperature dependent cladding thinning phenomenon was used for kinetic interpretation. As the first of a two-part study, this paper will focus on the exposure capsule performance, including metallographic cross-section preparation and preliminary results on the interface chemistry. [ABSTRACT FROM AUTHOR]

The Asian water plantain, Alisma orientale (Sam.) Juzep, is a traditional Chinese medicinal plant. The dried tubers of the Alisma orientale, commonly referred to as Alismatis rhizome (AR), have long been used in traditional Chinese medicine to treat a variety of diseases. Soil properties and the soil microbial composition are known to affect the quality and bioactivity of plants. Here, we sought to identify variations in soil fungal communities and soil properties to determine which would be optimal for cultivation of A. orietale. Soil properties, heavy metal content, and pesticide residues were determined from soils derived from four different agricultural regions around Shaowu City, Fujian, China, that had previously been cultivated with various crops, namely, Shui Dao Tu (SDT, rice), Guo Shu Tu (GST, pecan), Cha Shu Tu (CST, tea trees), and Sang Shen Tu (SST, mulberry). As fungi can either positively or negatively impact plant growth, the fungal communities in the different soils were characterized using long-read PacBio sequencing. Finally, we examined the quality of A. orientale grown in the different soils. Our results show that fungal community diversity of the GST soil was the highest with saprotrophs the main functional modes in these and SDT soils. Our data show that GST and SDT soils were most suitable for A. orientale growth, with the quality of the AR tubers harvested from GST soil being the highest. These data provide a systematic approach at soil properties of agricultural lands in need of replacement and/or rotating crops. Based on our findings, GST was identified as the optimal soil for planting A. orientale, providing a new resource for local farmers. [ABSTRACT FROM AUTHOR]

A hyperbranched ion-imprinted polymer (IIP) material containing multiple selective adsorption sites was synthesized using halloysite nanotubes, methyl acrylate, and ethylenediamine in the presence of a template ion [i.e. Cd (II) heavy metal]. The successful preparation of the Cd-IIP composition was confirmed by FT-IR, XRD, TEM, TGA, and elemental analysis. The polymers exhibited good adsorption of Cd (II) with a maximum adsorption capacity of 64.37 mg•g--1. The imprinting factor (α) for Cd (II) was 2.62 and the selection factor (β) was 1.78, indicating a specific adsorption of Cd (II) ion. The selection coefficients of Cd-IIP for Cd (II)/Pb (II), Cd (II)/Cu (II), Cd (II)/Ni (II), Cd (II)/Cr (III), and Cd (II)/Na (I) also indicated an excellent selectivity of the hyperbranched polymers for Cd (II) in the presence of competitive ions. The removal efficiency remained more than 75% after five cycles of desorption/adsorption. We envision that the HNTs based Cd-IIP has promising applications in the removal of Cd (II) from wastewater. [ABSTRACT FROM AUTHOR]

This article is devoted to the search for effective ways of neutralizing sewage sludge to obtain sludge-based reclamation material. It was necessary to solve the problems of deodorizing the sludge and fixing the mobile forms of heavy metals in its composition. The composition, effective for solving the assigned problems, was experimentally determined; it included quicklime, sodium hypochlorite and peat. In the presence of sodium hypochlorite in the sludge-based composition, oxidation processes occur with the chemical transformation of ammonia and hydrogen sulfide into non-toxic and odorless compounds. Lime combined with peat promotes the humification of sewage sludge and the binding of heavy metals. Based on the composition that showed the best results, a technology has been developed for the chemical treatment of sewage sludge in situ to produce reclamation material. [ABSTRACT FROM AUTHOR]

Tobacco smoking remains one of the leading causes of premature death worldwide. Electronic Nicotine Delivery Systems (ENDSs) are proposed as a tool for smoking cessation. In the last few years, a growing number of different types of ENDSs were launched onto the market. Despite the manufacturing differences, ENDSs can be classified as "liquid e-cigarettes" (e-cigs) equipped with an atomizer that vaporizes a liquid composed of vegetable glycerin (VG), polypropylene glycol (PG), and nicotine, with the possible addition of flavorings; otherwise, the "heated tobacco products" (HTPs) heat tobacco sticks through contact with an electronic heating metal element. The presence of some metals in the heating systems, as well as in solder joints, involves the possibility that heavy metal ions can move from these components to the liquid, or they can be adsorbed into the tobacco stick from the heating blade in the case of HTPs. Recent evidence has indicated the presence of heavy metals in the refill liquids and in the mainstream such as arsenic (As), cadmium (Cd), chromium (Cr), nickel (Ni), copper (Cu), and lead (Pb). The present review discusses the toxicological aspects associated with the exposition of heavy metals by consumption from ENDSs, focusing on metal carcinogenesis risk. [ABSTRACT FROM AUTHOR]

Zinc leaching residue is the waste residue produced by the wet zinc extraction process, which cannot be effectively utilized due to its complex composition and the presence of toxic heavy metals. At this stage, a large amount of residue is piled up in the tailing storage, there is a waste of resources and the risk of environmental pollution. This paper introduced a study on the preparation of glass-ceramic in building materials from zinc leaching residue by the sintering method, using silica sand and albite as additives. It was found that the glass-ceramics prepared with zinc leaching residue incorporation of 70–75 % and sintering temperature in the range of 900–1000 °C exhibited excellent mechanical properties and stable chemical properties. The zinc leaching residue content and the sintering temperature together controlled the crystallization process and influenced the properties of the glass-ceramic. Increasing the zinc leaching residue content caused an increase in the content of non-bridging oxygen bonds in the glass-ceramic, which led to an increase in the degree of polymerization of the matrix and a decrease in the activation energy of the crystallization, which promoted the crystallization process. Higher temperatures provided more energy for the crystal crystallization reaction and facilitated the process. The glass-ceramics showed good solidification of heavy metals and compliance with the requirements for various heavy metals in the toxicity leaching test. The glass-ceramic made from zinc leaching residue eliminated the risk of heavy metals contamination and was a green, harmless, high-performance material that can be used in a wide range of fields. [ABSTRACT FROM AUTHOR]

Thallium ecotoxicity was assessed in laboratory model experiments by changing in microbiological, biochemical, and phytotoxic properties of soils in the South of Russia: ordinary chernozem (Haplic Chernozem (Loamic)), seropesok (Eutric Arenosol), and slightly unsaturated brown forest soil (Eutric Cambisol), differing in texture, pH, and organic matter content. There was usually a direct relationship between Tl concentration and the deterioration rate of the studied soil properties. The ecotoxicity of Tl nitrate was higher as compared to Tl oxide. The ecotoxic effect of Tl was the strongest for chernozem and seropesok within 10 days and for brown forest soil within 30 days after contamination. Restoration of biological soil properties was recorded on the 90th day. The resistance to Tl contamination was the greatest for ordinary chernozem and the smallest for seropesok. The results obtained indicate a high ecotoxicity of Tl. [ABSTRACT FROM AUTHOR]

The main objective of this study is to assess the monitoring system of surface water quality in Can Tho using principal component analysis (PCA) and cluster analysis (CA). Water samples were monthly collected in 2020 at 35 sampling sites and then analyzed for 18 parameters including temperature, pH, turbidity, dissolved oxygen (DO), biological oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), ammonium (NH4 + -N), nitrate (NO3ˉ-N), nitrite (NO2ˉ-N), orthophosphate (PO4 3 ˉ-P), chromium (Cr), fluoride (F- ), arsenic (As), lead (Pb), mercury (Hg) and coliform. These values were compared with the national technical regulation on surface water quality and calculated water quality index (WQI). The findings indicated that surface water quality in Can Tho was contaminated by organic matters, suspended solids, and microorganisms. TSS, BOD and COD were high in the dry season, while high level of coliform was found in the wet season. The results of computed WQI showed that the surface water quality was from good to excellent. The PCA results show that 77.2% of water quality fluctuations in the study area were potentially affected by domestic, agricultural, industrial activities and hydrological factors (rainwater runoff, riverbank erosion). Moreover, the results of PCA revealed that water quality parameters could be diminished from 18 to 14 parameters without the loss of important for evaluating surface water quality. CA suggested that total sampling sites and frequencies in the current monitoring program are likely to reduce from 35 to 27 sites and 12 to 6-7 times/year, respectively. It is suggested that these findings can provide essential scientific information for local environmental managers in adjusting the surface water quality monitoring network in Can Tho city, Vietnam. [ABSTRACT FROM AUTHOR]

Because of environmental impact, there is a great need for chemosensors, especially for toxic heavy metals such as lead. The conventional instrumental analytical techniques rarely provide an available real-time sensing platform, thus the development of highly selective and stable synthetic chemosensor molecules is of great importance. Acridono-18-crown-6 ethers have such properties, and much research has proven their outstanding applicability in various supramolecular devices. In this present work, we aimed to enable their covalent immobilization capability by synthesizing functionalized derivatives while preserving the favored molecular recognition ability. Several new macrocycle analogues were synthesized, while synthetization difficulties and design aspects were also dealt with. The selectivity of the macrocycle analogues was studied using UV–Vis spectroscopy and compared with that of the parent compounds. The ultimate crown ether derivative showed high Pb2+-selectivity, reversibility (decomplexation by extraction with water) and stability. [ABSTRACT FROM AUTHOR]

In light of industrial developments, water pollution by heavy metals as hazardous chemicals has garnered attention. Addressing the urgent need for efficient heavy metal removal from aqueous environments, this study delves into using poly-γ-glutamic acid (γ-PGA) for the bioflocculation of heavy metals. Utilizing γ-PGA variants from Bacillus subtilis with different molecular weights and salt forms (Na-bonded and Ca-bonded), the research evaluates their adsorption capacities for copper (Cu), lead (Pb), and cadmium (Cd) ions. It was found that Na-bonded γ-PGA with a high molecular weight showed the highest heavy metal adsorption (92.2–98.3%), particularly at a 0.5% concentration which exhibited the highest adsorption efficiency. Additionally, the study investigated the interaction of γ-PGA in mixed heavy metal environments, and it was discovered that Na-γ-PGA-HM at a 0.5% concentration showed a superior adsorption efficiency for Pb ions (85.4%), highlighting its selectivity as a potential effective biosorbent for wastewater treatment. This research not only enlightens the understanding of γ-PGA's role in heavy metal remediation but also underscores its potential as a biodegradable and non-toxic alternative for environmental cleanup. The findings pave the way for further exploration into the mechanisms and kinetics of γ-PGA's adsorption properties. [ABSTRACT FROM AUTHOR]

This study investigates the synergistic effect and mechanism of gelling materials with blast furnace slag (BFS), steel slag (SS) and desulphurization gypsum (DG) as the main components on the hardening of heavy metal ions by lead and zinc tailings. It is found that lead and zinc tailing (LZT) is mainly composed of dolomite and quartz and contain small amounts of calcium, aluminum, iron, magnesium and other elements as well as heavy metals such as lead and zinc. By the mechanical activation method, it is found that the lead and zinc tailings powder has the largest specific surface area and the highest activity index when the ball milling time is 2 h. At a hardening timepoint of 28 d, the calcite crystals in the samples are intertwined with the amorphous C-S-H gel (C-S-H gels are mainly composed of 3CaO∙SiO2 and 2CaO∙SiO2), which enhances the structural strength of the samples. The chemical reaction analysis confirmed that the formation of calcite is a major driver for the hydration reaction of the steel slag–desulphurization gypsum (SSSDG) system. Overall, the slag, steel slag and desulphurization gypsum solid waste-based gelling materials have synergistic effects in hardening heavy metals by limiting the leaching of metal ions, adsorbing metal ions and hardening heavy metals, and facilitating the hydration process through the formation of compound salt precipitates. [ABSTRACT FROM AUTHOR]

To control heavy metal pollution effectively, prevention of heavy metal accumulations in agricultural soils should be the priority rather than remediation of heavy metal contamination. In this research, papers which contained input and output fluxes of Cd, As, Cr, Hg, and Pb in topsoil (the plough layer) of agricultural lands in Hunan, Zhejiang, the Yangtze River Delta, Hainan, and China as a whole were explored. Fluxes of heavy metal species were recalculated, and future trends of pollution were predicted. Also, cases regarding the application of technologies to control the input and output of heavy metals were analyzed. Results indicated that atmospheric decomposition was the dominant input source of heavy metals in all study sites except Hainan. The relative contributions of fertilizers, irrigation water, and straw returning fluctuated greatly among different sites. Cd pollution in all sites was the most serious, followed by Cr and Pb. In Hunan, Cd has already exceeded the maximum limit value and needs to be controlled urgently. The input of heavy metals from irrigation water, fertilizers, and straw returning could be controlled by proposing more policies to manage their quality and application amounts. The amount of heavy metals absorbed by plants could be increased by cultivating crops with hyperaccumulators and high-biomass plants. [ABSTRACT FROM AUTHOR]