Search Results (3,180)

This study explores the stabilization and utilization of hazardous waste (HW) derived from iron oxide powders containing arsenic, a byproduct of a water purification process. Cement paste samples were prepared with varying waste content (0.0%, 2.5%, 10% and 20% by weight) through mechanical mixing of all the components. Utilizing this waste offers two key environmental benefits: first, it addresses the issue of large-scale waste production globally by providing a method for its stabilization; second, it reduces cement consumption in concrete by serving as an admixture and filler, thereby lowering the cement industry’s significant CO₂ emissions. After 28 days, compressive strength and density tests were conducted, and the microstructure was examined using scanning electron microscopy and X-ray diffraction. The results demonstrated compressive strengths exceeding 20 MPa, with the presence of calcite, portlandite, and ettringite phases in the samples. Additionally, Weibull statistics were conducted over a wide number of samples per composition in order to account for the variability of the compression properties, which can be important for deciding the applications. The results showed that the prepared formulations can be used in structural applications such as walls, infrastructure, sidewalks, and soil stabilization. Full article

Arsenic (As), a highly toxic and carcinogenic heavy metal, poses significant risks to soil and water quality, while oxytetracycline (OTC), a widely used antibiotic, contributes to environmental pollution due to excessive human usage. Addressing the coexistence of multiple pollutants in the environment, this study investigates the simultaneous adsorption of As(III) and OTC using a novel bimetallic zinc-iron-modified biochar (1Zn-1Fe-1SBC). The developed adsorbent demonstrates enhanced recovery, improved adsorption efficiency, and cost-effective operation. Characterization results revealed a high carbon-to-hydrogen ratio (C/H) and a specific surface area of 1137 m² g⁻¹ for 1Zn-1Fe-1SBC. Isotherm modeling indicated maximum adsorption capacities of 34.7 mg g⁻¹ for As(III) and 172.4 mg g⁻¹ for OTC. Thermodynamic analysis confirmed that the adsorption processes for both pollutants were spontaneous (ΔG < 0), endothermic (ΔH > 0), and driven by chemical adsorption (ΔH > 80 kJ mol⁻¹), with increased system disorder (ΔS > 0). The adsorption mechanisms involved multiple interactions, including pore filling, hydrogen bonding, electrostatic attraction, complexation, and π-π interactions. These findings underscore the potential of 1Zn-1Fe-1SBC as a promising adsorbent for the remediation of wastewater containing coexisting pollutants. Full article

Phytoremediation is an economically viable and environmentally friendly technique among various arsenic-contaminated soil remediation technologies. Field plot experiments were conducted to investigate the effects of peanut intercropping with sunflower, lucerne, and jute on the growth and development of intercropped crops and the efficiency of arsenic (As) remediation in polluted soil within the intercropping system. The results indicate that intercropping peanuts with other crops can enhance the biomass and yield of the crops. The land equivalent ratios (LER) of the three intercropping patterns were 1.03, 1.70, and 1.17, respectively. The intercropping pattern also influences the absorption and accumulation of As in crops. Total arsenic accumulation in peanuts intercropped with jute reached 493 μg·plant⁻¹, which was significantly higher by 29.5% compared to peanut monoculture. Additionally, the translocation factor (TF) and bioaccumulation factor (BCF) of peanut seeds were significantly higher in peanut-jute intercropping compared to other treatments, but the As content of peanut seeds in all treatments complied with national food safety standards (GB2762-2022, 0.5 mg·kg⁻¹). Intercropping of peanuts altered the pH and Eh values of rhizosphere soil, further influencing the percentage content of various forms of As in the soil, and reducing the mobility and effectiveness of As. The metal removal equivalent ratios (MRER) for the three intercropping patterns were 1.30, 2.11, and 1.26, respectively. The intercropping of peanuts and lucerne resulted in an MRER of 2.11. It indicates that peanut intercropping has a significant promotion and high restoration efficiency on the growth and development of lucerne. Therefore, among the three patterns, the peanut intercropping lucerne pattern has the best effect in applying to contaminated soil, and can better realize the integration of economic and ecological benefits. Full article

Mīnā’ī wares, crafted during the 12th–13th centuries, represent some of the earliest examples of sophisticated painted enamel decoration by potters. Due to the thinness of these enamel layers, their detailed characterization remains challenging, even with the use of advanced techniques, such as Proton-Induced X-ray Emission (PIXE) analysis and Rutherford Backscattering Spectrometry (RBS). This study provides the first combined non-invasive analysis, using X-ray fluorescence (XRF) and Raman spectroscopy, of five shards attributed to mīnā’ī wares. For comparison, two İznik shards from the 17th century, which feature similarly styled but thicker enamel decorations, were also analyzed. Interestingly, the mīnā’ī paste was found to contain lead and tin, suggesting the use of a lead-rich frit in its composition. This finding was confirmed through micro-destructive analysis, using Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM–EDS). Elements, such as rubidium (Rb), strontium (Sr), yttrium (Y), and zirconium (Zr), produced significant XRF signals and effectively distinguished mīnā’ī wares from İznik wares. A uniform tin-rich glaze, measuring 300–500 µm in thickness, was used as a base layer for the much thinner painted mīnā’ī enamels. The colored areas (blue, turquoise, red, green, black, white, eggplant) revealed the presence of various coloring agents and phases, such as spinels, chromite, and ions like Cu²⁺ and Co²⁺, as well as opacifiers like cassiterite and lead–calcium/potassium arsenates. Two distinct cobalt sources were identified: one associated with arsenic and the other with manganese and nickel. These cobalt sources are comparable to those used in İznik pottery. For the first time, boron was detected in the blue enamel of mīnā’ī wares. Full article

In recent years, the influence of environmental factors on organismal aging has garnered increasing attention. Studies have shown that sleep deprivation and environmental pollutants could accelerate the emergence of multiple organismal aging phenotypes. In addition, studies have shown that chronic exposure to sodium arsenite (iAs) induces skeletal muscle atrophy and the inhibition of melatonin secretion in rats. This study aimed to reveal the synergistic effect of sleep deprivation and arsenite exposure on skeletal muscle aging, including reduced limb grip strength and skeletal muscle mass, along with the serum levels of melatonin (MT) and cortisol (COR) in C57BL/6J mice. The results demonstrated that while exposure to arsenite for 12 weeks or sleep deprivation (SD) for 4 weeks did not exert significant effects on limb grip strength or skeletal muscle mass, their combination exhibited a synergistic effect on skeletal muscle aging. Notably, the iAs+SD group exhibited a significant decline in limb grip strength by Week 12, accompanied by a reduced gastrocnemius muscle mass and muscle index. The pathological analysis showed muscle fiber atrophy, a shift towards slow-twitch muscle fibers (type I), and shortened telomere length. Additionally, oxidative damage was increased in the SD and iAs+SD groups, with decreased levels of SOD and GPx and elevated levels of MDA in the iAs+SD group. The serum MT level and MT/COR ratio were significantly reduced, while the serum COR level was elevated in the iAs+SD group compared to the other groups. A correlation analysis further revealed that the serum MT level and the MT/COR ratio were positively correlated with limb grip strength, muscle index, and telomere length, whereas the serum COR level exhibited negative correlations with these parameters. These findings suggest that sleep deprivation and subchronic exposure to arsenite synergistically induce skeletal muscle aging, and that the disruption of the balance between MT and COR potentially serves as a significant risk factor. Full article

The combined pollution of microplastics (MPs) and arsenic (As) has gradually been recognized as a global environmental problem, which calls for detailed investigation of the synergistic toxic effects of MPs and As on plants and their mechanisms. Therefore, the interaction between polystyrene microplastics (PS-MPs) and arsenate (AsO₄³⁻) (in the following text, it is abbreviated as As(V)) and its toxic effects on lettuce were investigated in this study. Firstly, chemisorption was identified as the main mechanism between PS-MPs and As(V) by the analysis of adsorption kinetics, adsorption thermodynamics, and Fourier transform infrared spectroscopy (FTIR). At the same time, the addition of As(V) promoted the penetration of PS-MPs through the continuous endodermal region of the Casparis strip. Furthermore, compared with the CK group, it was found that the co-addition of As(V) exacerbated the lowering effect of PS-MPs on the pH value of the rhizosphere environment and the inhibitory effect on root growth. In the P20V10 group, the pH decreased by 33.0%. Compared to the CK group, P20, P20V1, and P20V10 decreased the chlorophyll content by 68.45% (16 SPAD units), 71.37% (17.73 SPAD units), and 61.74% (15.36 SPAD units) and the root length by 19.31% (4.18 cm), 50.72% (10.98 cm), and 47.90% (10.37 cm) in lettuce. P5V10 and P20V10 increased CAT content by 153.54% (33.22 U·(mgprol)⁻¹) and 182.68% ((38.2 U·(mgprol)⁻¹)), Ca by 31.27% and 37.68%, and Zn by 41.85% and 41.85%, but the presence of As(V) reduced Na by 22.85% (P5V1) and 49.95% (P5V10). The co-exposure significantly affected the physiological and biochemical indicators as well as the nutritional quality of the lettuce. Finally, the metabolomic analysis of the lettuce leaves showed that combined pollution with PS-MPs and As(V) affected the metabolic pathways of the tricarboxylic acid cycle (TCA cycle), sulfur metabolism, and pyruvate metabolism. This study provides data for pollution management measures for co-exposure to PS-MPs and As(V). Full article

Alzheimer’s disease (AD) is traditionally viewed through the lens of the amyloid cascade hypothesis, implicating amyloid-beta and tau protein aggregates as the main pathological culprits. However, burgeoning research points to the brain’s resident immune cells, microglia, as critical players in AD pathogenesis, progression, and potential therapeutic interventions. This review examines the dynamic roles of microglia within the intricate framework of AD. We detail the involvement of these immune cells in neuroinflammation, explaining how their activation and response fluctuations may influence the disease trajectory. We further elucidate the complex relationship between microglia and amyloid-beta pathology. This study highlights the dual nature of these cells, which contribute to both aggregation and clearance of the amyloid-beta protein. Moreover, an in-depth analysis of the interplay between microglia and tau unveils the significant, yet often overlooked, impact of this interaction on neurodegeneration in AD. Shifting from the conventional therapeutic approaches, we assess the current AD treatments primarily targeting amyloid and tau and introduce novel strategies that involve manipulating microglial functions. These innovative methods herald a potential paradigm shift in the management of AD. Finally, we explore the burgeoning field of precision diagnosis and the pursuit of robust AD biomarkers. We underline how a more profound comprehension of microglial biology could enrich these essential areas, potentially paving the way for more accurate diagnostic tools and tailored treatment strategies. In conclusion, this review expands on the conventional perspective of AD pathology and treatment, drawing attention to the multifaceted roles of microglia. As we continue to enhance our understanding of these cells, microglial-focused therapeutic interventions emerge as a promising frontier to bolster our arsenal to fight against AD. Full article

Iridescent iron oxides known as rainbow hematite and turgite are found in a variety of localities worldwide and display a variety of beautiful interference colors. Usually, there is a thin layer of nanocrystals containing aluminum and phosphorous coats, such as with hematite, although one example of aluminum with arsenic is presented. Infrared spectra of samples with thicker layers of these nanocrystals show absorption in the phosphate region. The thin films that range from tens to hundreds of nanometers thick are believed to cause the color. High-resolution secondary electron imaging shows that the thin film consists of nanocrystals arranged in three directions (120° apart). The rod-shaped crystals have a width from 5 to 35 nm and display the same morphology on all samples, irrespective of if they contain phosphorus or arsenic. The minute crystals have failed to produce either an X-ray powder diffraction pattern, an electron back-scatter diffraction pattern in SEM, or an electron diffraction ring pattern under TEM. Raman spectra are dominated by hematite features. Infrared ATR spectra of the bulk material show mostly hematite with occasional minor amounts of goethite and phosphate. Full article

Soil metal(loid) pollution is a threat to ecological and environmental safety. The vegetation recovery in mining areas is of great significance for protecting soil resources. In this study, (1) we first gathered four types of soils to analyse their contamination degree, including tailings mud (TM), wasteland soil (TS) very near TM, as well as non-rhizosphere soils of pepper (PF) and maize (MF) in a farmland downstream from the TM (about 5 km). Geo-accumulation and potential ecological risk indices indicated that the soil samples were mainly polluted by antimony (Sb), arsenic (As), cadmium (Cd), chromium (Cr), lead (Pb), and copper (Cu) to different degrees. Leachates of TM resulted in increased Sb, As, and Cd accumulation in TS. (2) Then, we sampled six local plants growing in the TS to assess the possibilities of using these plants as recovery vegetation in TS, of which Persicaria maackiana (Regel) Nakai ex T. Mori absorbed relatively high Sb concentrations in the leaves and roots. (3) After that, we collected rhizosphere soil and tissue samples from eight crops on the above farmland to assess their capacities as recovering vegetation of contaminated farmland soil, of which the fruits of maize accumulated the lowest concentrations of most monitored metal(loid)s (except for Pb). Further, we compared the differences in the bacterial community structure of MF, PF, TM, and TS to assess capacities of cultivating pepper and maize to improve soil microbial community structure. The MF displayed the best characteristics regarding the following attributes: (1) the highest concentrations of OMs and total P; (2) the highest OTU numbers and diversity of bacteria; and (3) the lowest abundance of bacteria with potentially pathogenic and stress-tolerant phenotypes. Full article

Heavy metal contamination in soil is a global issue threatening human health and ecosystems. Accurate spatial maps of heavy metals (HMs) are vital to mitigating the adverse effects on the ecosystem. This study utilizes GIS and multivariate analysis to evaluate HMs in agricultural soils from Al Ghat Governorate, Saudi Arabia, analyzing Al, As, Co, Cr, Cu, Fe, Mn, Ni, Pb, V, and Zn using ICP-AES in 35 soil samples. Methods included contamination factor (CF), enrichment factor (EF), risk index (RI), geoaccumulation index (Igeo), pollution load index (PLI), soil quality guidelines (SQGs), and multivariate analysis. The soils, characterized by sandy texture, low organic matter, and alkalinity due to arid conditions and high calcium carbonate, had the following HM concentrations (mg/kg) in descending order: Fe (11,480) ˃ Al (7786) ˃ Mn (278) ˃ Zn (72.37) ˃ Ni (28.66) ˃ V (21.80) ˃ Cr (19.89) ˃ Co (19.00) ˃ Cu (12.46) ˃ Pb (5.46) ˃ As (2.69). EF, CF, and Igeo suggest natural sources for most HMs, predominantly from the sedimentary sequence, with localized Zn, Pb, Co, Mn, and Cu enrichment linked to mixed natural and agricultural influences. PLI and RI indicated acceptable contamination levels, posing no ecological risk. All samples fell below SQG thresholds for As, Cu, Pb, and Cr, confirming minimal ecological threat. Statistical analysis highlighted sedimentary cover as the primary HM source, with agricultural activities contributing to Co, Cu, Ni, and Pb levels. Full article

Nowadays, arsenic (As) accumulation in agricultural soils and its transfer in crop yields is representing a growing concern that threatens food safety and security in the Mediterranean environment. Soil tillage and fertilization may increase the accumulation of As in plant tissues; therefore, there is a need to develop sustainable agronomical practices capable of supporting crop yield while mitigating As accumulation. The current study was carried out through a 7-year experiment with the aim of evaluating the As uptake by different parts of the durum wheat plant. The experimental treatments include the following: (i) three soil tillage practices (plowing, subsoiling, and spading) and (ii) two fertilization methods (mineral and organic). A factorial randomized complete block design with three replications was adopted. The experimental period refers to the 2018/2019, 2019/2020, and 2020/2021 growing seasons. The results suggest that the maximum level of As was found in plant roots and the minimum in wheat kernels. The chemical fertilization as 2020 × Mineral (1.522 mg As kg⁻¹ d.m.) and 2020 × Plowing (1.855 mg As kg⁻¹ d.m.) had the maximum As content in the roots. Conversely, the content of As was at a minimum in the wheat kernels for organic fertilization as 2021 × Organic (0.012 mg As kg⁻¹ d.m.) and subsoiling tillage as 2021 × Subsoiling (0.008 mg As kg⁻¹ d.m.). Moreover, the application of an organic fertilization source as a tool for enhancing the soil organic matter content also significantly decreased the As content. The results suggest that reduced tillage practices and the adoption of organic amendment could be classified as sustainable agronomic practices in agri-food systems, which are able to improve plant quality and assure a safe consumption of wheat kernels. Full article

Damage to human health caused by As-contaminated water can be prevented using proper As-removal techniques, such as employing excellent arsenic adsorbents. In this study, the combined addition of Mg- and Ca-based adsorbents was investigated for the efficient removal of As from contaminated water. Following a previous study on As(V), As-removal tests targeting As(III) and several additional tests, including X-ray diffraction analysis, were conducted to clarify the mechanism of the improved performance of the combined-addition As removal. Similarly as for As(V), the combined additions of both MgCO₃ + CaO and MgCO₃ + Ca(OH)₂ improved As(III)-removal performance while inhibiting the leaching of base material components; however, they did not remove As(III) as effectively as As(V). The differences in the removal ratios of As(V) and As(III) in these combined additions were concluded to be primarily due to the different As-removal mechanisms. Mg(OH)₂ and CaCO₃ were generated, and As(III) was incorporated into the generated precipitate of Mg(OH)₂ but not into that of CaCO₃. Conversely, As(V) was incorporated into both Mg(OH)₂ and CaCO₃. Additionally, MgCO₃ + Ca(OH)₂ was evaluated as a more efficient combined-addition method because MgCO₃ + Ca(OH)₂ exhibited a higher As-removal ratio value than MgO + CaO. Proposals have been made to remove As(III) using activated carbon modified with heavy metals or transition elements, or concrete waste grafted with polymers, but these methods are complicated to prepare, costly, and involve the risk of leaching of harmful components. Adsorbents that use general Mg and Ca components as their base material do not contain such harmful components. The Mg- and Ca-based adsorbents are readily available and low-cost, and, best of all, there is no concern that they will leach harmful components. Therefore, widespread use of Mg- and Ca-based adsorbents as a measure against arsenic contamination could greatly contribute to a sustainable society. Full article

Soil, geochemical, microbiological, and archeological studies were conducted at eight settlements dating from the Paleolithic to Late Medieval and Modern Ages near the southern Trans-Urals Mountains, Russia. The forest-steppe landscapes, rivers, and abundant mineral resources have attracted people to the region since ancient times. Cultural layers (CLs) are marked by finds of ceramics fragments, animal bones, stone, and metal tools. The properties of CLs include close-to-neutral pH, being well structured, the absence of salinity, enrichment with exchangeable calcium, and anthropogenic phosphorus (0.2–0.4%). The majority of CLs start at a depth of 3–25 cm, extend to 40–60 cm, and contain 6–10% organic carbon (Corg) in the 0–20 cm layer, reflecting carbon input from modern-day processes. At the Ishkulovo site (0.6–0.8 ka BP), Corg decreases to 1.3% because the CL is below 80 cm, and in the absence of fresh organic material input, carbon has been mineralized. The proximity of sites to deposits of copper, chromium, zinc, and manganese in the Ural Mountains creates natural high-content anomalies in the region, as indicated by their abundance in soils and parent rocks. In the past, these elements were also released into CLs from metal products, ceramic fragments, and raw materials used in their manufacture. The sites are quite far (18–60 km) from the Magnitogorsk Metallurgical plant, but industrial stockpiles of S (technogenic coefficient—Ct 30–87%), and, less often, Cr, Mn, and Sr (Ct 30–40%) accumulated in surface layers. These three factors have led to the concentration of pollutants of the first (arsenic, chromium, lead, and zinc) and second (cobalt, copper, and nickel) hazard classes at CLs, often in quantities 2–5 times higher than values for parent materials and geosphere average content (“Clarke” value), and, and less often, more than the allowable content for human health. This may have influenced their health and behavioral functions. Due to the above properties, chernozems have a high buffering capacity and a strong bond with heavy metals. Therefore, no inhibition of microbes was observed. The microbial biomass of the 0–10 cm layer is high, 520–680 µg C/g, and microbes cause the emission of 1.0 C-CO₂ µg/g of soil per hour. During the ancient settlements’ development, a favorable paleoclimate was noted based on the data cited. This contributed to the spread of productive paleolandscapes, ensuring the development of domestic cattle breeding and agriculture. Full article

Potato (Solanum tuberosum L.) is the world’s third most popular vegetable in terms of consumption and the fourth most produced. Potatoes can be easily cultivated in different climates and locations around the globe and often in soils contaminated by heavy metals due to industrial activities. This study assessed heavy metal accumulation in different organs of three S. tuberosum L. varieties (Agria, Désirée, and Red Lady) grown in different substrate formulations containing slag and waste from the Caveira polymetallic sulfite mine in Portugal. Results reveal that Cu, Pb, and As accumulation in the different organs of the plant depends on variety and substrate formulation, with tubers exceeding reference values from the literature. Tubers accumulated less Cu (varying between 17.3 and 32 mg/kg), Pb (varying between 5 and 27.6 mg/kg) and As (varying between 4 and 14.8 mg/kg) compared to other plant organs, and the Désirée variety exhibited high Pb (with a maximum of 27.6 mg/kg) accumulation in tubers compared to the remaining varieties. Although the phenological development of plants was not impacted, substrate formulation played a critical role in the plant’s metal uptake. The Agria variety presented a lower contamination risk in tubers, but potato cultivation in contaminated soils can present a risk to human health. Full article

The pervasive and often indiscriminate use of antibiotics has accelerated the emergence of drug-resistant bacterial strains, thus presenting an acute threat to global public health. Despite a growing acknowledgment of the severity of this crisis, the current suite of strategies to mitigate antimicrobial resistance remains markedly inadequate. This paper asserts the paramount need for the swift development of groundbreaking antimicrobial strategies and provides a comprehensive review of an array of innovative techniques currently under scrutiny. Among these, nano-antimicrobials, antimicrobials derived from ribosomal proteins, CRISPR/Cas-based systems, agents that undermine bacterial bioenergetics, and antimicrobial polysaccharides hold particular promise. This analysis gives special attention to CRISPR/Cas-based antimicrobials, scrutinizing their underlying mechanisms, exploring their potential applications, delineating their distinct advantages, and noting their likely limitations. Furthermore, we extend our exploration by proposing theoretical advancements in antimicrobial technology and evaluating feasible methods for the effective delivery of these agents. This includes leveraging these advances for broader biomedical applications, potentially revolutionizing how we confront bacterial pathogens in the future, and laying a foundation for extended research in multimodal therapeutic strategies. Full article