Distribution Of Metals Research Articles

Impacts of sugarcane bagasse-derived biochar and apatite on heavy metal speciation in incubated heavy metal-contaminated soil.

Heavy metal contamination in soils poses significant environmental and health risks, necessitating effective remediation strategies. This study investigates the time-dependent effects of sugarcane bagasse-derived biochar and apatite as soil amendments on the chemical speciation of heavy metals in polluted soil. Despite their known efficacy, the specific influence of these amendments on the distribution of heavy metal chemical fractions over time remains underexplored. Incubated experiments were conducted over one month using soil samples spiked with Biochar and apatite. Pb- and Zn-contaminated soils were incubated with biochar and apatite at varying ratios: biochar at 5% and 10%, and biochar/apatite mixtures at 2.5:2.5% and 5:5% ratios (in mass). Changes in heavy metal speciation were analyzed using Tessier's sequential extraction procedure. Results demonstrate significant shifts in the distribution of heavy metals across soil phases, suggesting potential reductions in bioavailability and environmental mobility. Incubation with varying application rates of biochar and apatite revealed diverse effects on Pb and Zn chemical fractions. Amendments reduced the exchangeable fraction of Pb and Zn by up to 38.5% and 47.7%, respectively, while increasing their more stable F4 and F5 fractions. Proposed mechanisms likely include cation exchange (swapping of ions between the soil and amendments), precipitation (formation of solid compounds), complexation with functional groups/minerals, and physical adsorption (attachment of metal ions) on biochar surfaces The efficacy of biochar and apatite underscores their promise for remediating Pb and Zn in contaminated soils, though variability in efficacy across different soil types warrants further investigation. These findings indicate the potential for practical applications in large-scale soil remediation projects. Further research is needed to assess the persistence of heavy metal stabilization over time and under varying environmental conditions.

A pristine view of galactic globular clusters and their peripheries: Omega centauri

Abstract The central regions of the globular cluster Omega Centauri (ω Cen) have been extensively studied, but its outer regions and tidal structure have been less so. Gaia’s astrometry uncovered substantial tidal substructure associated with ω Cen, yet the lack of chemical tagging makes these associations tenuous. In this paper, we utilise the Gaia-Synthetic CaHK-band photometry, metallicities from the Pristine survey and Gaia’s astrometry to explore up to a clustercentric radius of 5 degrees from ω Cen. We identify ω Cen-like stars based on proper motion, colour-magnitude and colour-colour space, exploring the morphology, and stellar populations of the outer regions. Our probabilistic approach recovers the tidal tails of ω Cen, and we investigate the metallicity distribution of ω Cen ranging from a radius of 15 arcmin to the tidal radius, and beyond into the tidal tails. We present (1) two components between 15 arcmin and tidal radius at -1.83 and 1.45 dex which are also the dominant populations within 15 arcmin, and (2) the first evidence that the same two populations in the outer regions of the cluster are present outside the tidal radius and into the tidal tails. These populations are mixed about the stream, and are typically amongst the faintest stars in our sample; all indicating that the tidal tails are made of tidally stripped ω Cen stars.

Understanding the Mechanisms Behind the Distribution of Galactic Metals

Abstract The evolution and distribution of metals within galaxies are critical for understanding galactic evolution and star formation processes, but the mechanisms responsible for shaping this distribution remain uncertain. In this study we carry out high-resolution simulations of an isolated Milky Way-like galaxy, including a star-by-star treatment of both feedback and element injection. We include seven key isotopes of observational and physical interest, and which are distributed across different nucleosynthetic channels—primarily AGB stars (N, Ba, Ce), supernovae (O, Mg, S), and Wolf-Rayet stars (C)show measurably different correlation statistics in space and time and their fluctuations. This difference arises from the distinct ejection mechanisms associated with each nucleosynthetic process. The large-scale properties ensure that different elements, despite having different nucleosynthetic origins, are highly correlated with one another (>0.85 for all, >0.99 for same origins), and their spatial correlations vary together in time. However small-scale variations naturally break elements into distinct nucleosynthetic familiars, with elements originating from the same channels correlating better with each other than with elements from different origins. Our findings suggest both challenges and opportunities for ongoing efforts to use chemical measurements of gas and stars to unravel the history and physics of galaxy assembly.

Distribution and risk assessment of heavy metals in the upper, middle, and lower reaches of the Yellow River wetlands

Distribution and risk assessment of heavy metals in the upper, middle, and lower reaches of the Yellow River wetlands

Spatial distribution, environmental contamination and health risk assessment of metals in surface soils of Lesser Himalaya, Jammu and Kashmir, India

Spatial distribution, environmental contamination and health risk assessment of metals in surface soils of Lesser Himalaya, Jammu and Kashmir, India

Heavy metals pollution in riverine sediments: Distribution, source, and environmental implications.

This research reports heavy metal pollution in riverine sediments from River Kabul, Pakistan, which could endanger human health and ecology via the food web. The results revealed a substantial special variation in the average contents (mg/kg) of chromium (Cr), manganese (Mn), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), cadmium (Cd), mercury (Hg), lead (Pb), iron (Fe), and aluminum (Al) in riverine sediments, in the order of Fe (20,234.51) > Al (17,550.86) > Mn (375.45) > Zn (149.08) > Ni (89.11) > Cr (83.36) > Pb (45.29) > Cu (19.86) > Cd (7.48) > Co (6.28) > Hg (0.81). Among the heavy metals, Cd exhibited the highest degree of pollution along the river, followed by Hg > Ni > Zn > Pb > Al > Cr > Mn > Fe > Cu > Co. The overall contamination factor (CF) values for the sum of heavy metals were highest at monitoring site S-9, followed by S-8 > S-10 > S-6 > S-5 > S-7 > S-1 > S-4 > S-12 > S-3 > S-2 > S-1 with pollution load index (PLI) > 1, whereas the geo-accumulation index (Igeo) values of Cd and Hg fluctuated between Levels 3, 4, and 6, suggesting moderate to extreme pollution in the river. The correlation statistics determined the fate and distribution of heavy metals by establishing significant positive correlations between the specific metals of bounded sediments. The cluster analysis separates the correlated metals into Groups A and B, and Groups 1 and 2. While the principal component analysis evaluates the qualitative behavior of clustering by discerning industrial, agrochemicals, mining, and domestic wastewater discharges, leakages of lubricants along with multiple geogenic inputs, erosion of mafic and ultramafic rocks, and minimal atmospheric deposition are all potential sources of Cr, Mn, Co, Ni, Cu, Zn, Cd, Hg, Pb, Fe, and Al contamination. In terms of risk, the contaminations of Mn, Co, Cu, Zn, and Pb in riverine sediments were 85, 100, 100, 17, and 11%, respectively, representing a rare biological influence because their value is less than their corresponding threshold effect concentrations (TECs), whereas the levels of Mn, Ni, Cd, and Hg were above their probable effect concentrations (PECs) of 100, 100, 81, and 52%, respectively, representing prominent adverse biological influence. Based on consensus-based TECs and PECs, the contamination levels of Cr, Mn, Zn, Cd, Hg, and Pb were 100, 85, 83, 19, 48, and 90%, respectively, indicating occasionally exhibited adverse biological effects on the riverine population. Besides, the overall potential ecological risk index (PERI) of Cd and Hg, in particular, exhibited the maximum pollution level ( ≥ 320), suggesting a very high potential ecological risk in the drainage that requires special attention from pollution control authorities.

Core to Cosmic Edge: SIMBA-C’s New Take on Abundance Profiles in the Intragroup Medium at z=0

We employ the simba-c cosmological simulation to study the impact of its upgraded chemical enrichment model (Chem5) on the distribution of metals in the intragroup medium (IGrM). We investigate the projected X-ray emission-weighted abundance profiles of key elements over two decades in halo mass (1013≤M500/M⊙≤1015). Typically, simba-c generates lower-amplitude abundance profiles than simba with flatter cores, in better agreement with observations. For low-mass groups, both simulations over-enrich the IGrM with Si, S, Ca, and Fe compared to observations, a trend likely related to inadequate modeling of metal dispersal and mixing. We analyze the 3D mass-weighted abundance profiles, concluding that the lower simba-c IGrM abundances are primarily a consequence of fewer metals in the IGrM, driven by reduced metal yields in Chem5, and the removal of the instantaneous recycling of metals approximation employed by simba. Additionally, an increased IGrM mass in low-mass simba-c groups is likely triggered by changes to the AGN and stellar feedback models. Our study suggests that a more realistic chemical enrichment model broadly improves agreement with observations, but physically motivated sub-grid models for other key processes, like AGN and stellar feedback and turbulent diffusion, are required to realistically reproduce observed group environments.

Distribution of metal(loid)s in size fractions of carbonate-rich marine sediments: Detrital vs. authigenic origin of carbonates

Distribution of metal(loid)s in size fractions of carbonate-rich marine sediments: Detrital vs. authigenic origin of carbonates

A self-designed pyrolysis-gasification-combustion pilot plant for rural solid waste disposal: The elucidation of emission factors

The research group developed a pyrolysis-gasification-combustion pilot plant (PGCP) to treat rural solid waste (RSW). Based on the study of previous operating conditions, this study further explored the characteristics of potential secondary pollutants in the plant, such as slag, fly ash and flue gas. In the present study, X-ray fluorescence (XRF), X-ray diffraction (XRD) and scanning electron microscope (SEM) were used to analyze slag and fly ash. Besides, the leaching toxicity, content and morphology distribution of heavy metals (e.g., Cu, Pb, Cd, Zn and Cr) in the slag of PGCP were also studied as well as the emission characteristics of various pollutants in flue gas. Results show that slag mainly contains CaCO3 and SiO2, while CaCO3 is mainly contained in fly ash. Moreover, the leaching toxicity of heavy metals in the slag did not exceed the limit value of the standard in China. The present study could provide technical support and data for optimizing the operation of plant-scale pyrolysis of RSW.

Natural factor-based spatial prediction and source apportionment of typical heavy metals in Chinese surface soil: Application of machine learning models.

Predicting the natural distribution of heavy metals (HMs) in soil is important to understand the potential risk of pollution. However, suitable technologies are still lacking for wide scale due to the large spatial heterogeneity. In this study, we developed machine learning models for predicting natural contents of five typical HMs in soil, including As, Cd, Cr, Hg and Pb. It was found that the optional random forest (RF) model had the best performance with the R2 up to 0.64. Based on this model, potential distribution of the five HMs explored that elevated contents were mainly concentrated in the southwest and south central of China. Feature analysis illustrated that importance of natural factors followed the order of geological attributes > soil properties > climatic conditions > ecological functions. In particular, lithology of the parent material dominated the content of metals, with the contributions of 18 - 25%. Moreover, soil properties of pH, cation exchange capacity, profile depth of soil and vegetation coverage had different influences on HMs, due to the variability in the properties of different HMs. This study developed a mapping relationship between natural factors and soil HMs by data science method, which may provide instructive information for pollution control and planning decisions.

Distribution of heavy metals in surface sediments of a Coastal Lagoon (Akyatan Lagoon, Northeastern Mediterranean Sea): Ecological and potential health risk assessment

Distribution of heavy metals in surface sediments of a Coastal Lagoon (Akyatan Lagoon, Northeastern Mediterranean Sea): Ecological and potential health risk assessment

Pathways and risk analysis of arsenic and heavy metal pollution in riverine water: Application of multivariate statistics and USEPA-recommended risk assessment models.

This study analyzed surface water from the River Swat, Pakistan, using inductively coupled plasma mass spectrometry, multivariate statistical techniques, and US-EPA risk assessment models to evaluate the concentrations, distribution, pathways, and potential risks of arsenic (As) and heavy metals, including chromium (Cr), manganese (Mn), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), cadmium (Cd), mercury (Hg), and lead (Pb). The results revealed significant correlations (p≤0.01) among metals that indicated common pollution sources, likely influenced by anthropogenic point and non-point activities. Along the monitored sites (S1-S10), the mass flow of ∑metals showed a dynamic pattern: progressively increasing downstream, decreasing at S6-S7, rising again at S7-S8, and then steadily declining toward S10, with Ni being the most abundant metal, followed by Cr>As> Cu>Mn>Co>Zn>Hg>Cd>Pb. The As and Heavy Metal Pollution Index (HPI), As and Heavy Metal Evaluation Index (HEI), and Pollution Index (PI) revealed variations in pollution levels, ranking the metals in the orders of Co>As> Cr>Cd>Mn>Hg>Ni>Pb>Cu>Zn, As> Cr>Ni>Hg>Cd>Co>Mn>Cu>Zn>Pb, and Hg>Ni>As> Co>Cu>Cd>Mn>Zn>Pb, respectively. However, according to the risk assessment, overall individual metal contamination in the River Swat water was below the ecological risk threshold (ERI〈110). Where, the Chronic Daily Intakes (CDIs), Hazard Quotients (HQs), Hazard Indices (HIs), Cancer Risks (CRs), and Total Cancer Risks (TCRs) of Cr, Mn, Co, Ni, Cu, Zn, As, Cd, Hg, and Pb associated with daily river water intake and dermal contact indicate that long-term exposure to untreated river water may pose both carcinogenic and non-carcinogenic health risks to residents.

Distribution and transformation behavior of heavy metals and phosphorus during sewage sludge pyrolysis

Distribution and transformation behavior of heavy metals and phosphorus during sewage sludge pyrolysis

Groundwater quality and its impact due to hydraulic fracturing activities around oil and gas drilling sites: A comprehensive study on distribution, correlation, ecological and health risk assessment of heavy metals

Groundwater quality and its impact due to hydraulic fracturing activities around oil and gas drilling sites: A comprehensive study on distribution, correlation, ecological and health risk assessment of heavy metals

Soil remediation by co-disposal in sintered brick kilns: Migration characteristics of heavy metals in bricks and the kiln.

Rapid industrialization has led to the widespread accumulation of heavy metal-contaminated soils, posing significant environmental and health risks. Utilizing remediated soil for the production of sintered bricks offers a sustainable and effective solution. However, the migration and immobilization mechanisms of heavy metals during the sintering process, both within the tunnel kiln and the brick matrix, require detailed investigation. This study examined the distribution of heavy metals in the tunnel kiln and analyzed the differences in heavy metal content and leaching behavior between the inner and outer layers of the bricks. Bricks containing 15% remediated soil were prepared, and it was observed that the majority of heavy metals were effectively immobilized, with retention rates ranging from 90.6% to 99.9%. Selenium (Se), however, exhibited significant volatility, with a retention rate of only 64.3%. The outer layer of the brick body contained higher concentrations of As and Pb compared to the inner layer. Conversely, leaching tests showed lower leaching rates of Mn, Ni, Cu, and Zn in the inner layers, while As and Pb exhibited higher leaching rates in the inner layers. These findings underscore the varying migration and transformation behaviors of different heavy metals during sintering, both within the kiln and the brick layers. The study highlights the potential of doped sintered bricks as sustainable building materials, ensuring effective heavy metal stabilization with minimal environmental risk, and providing a promising pathway for the safe reuse of contaminated soils.

Sedimentological and mineral control on metal(oid) distribution in sediments along the source (base rock, mining waste)‒pathway (stream sediment)‒receptor (floodplain sediment) chain in a catchment impacted by historical mining: a case study from the Baiut Mining Area, Romania

Sedimentological and mineral control on metal(oid) distribution in sediments along the source (base rock, mining waste)‒pathway (stream sediment)‒receptor (floodplain sediment) chain in a catchment impacted by historical mining: a case study from the Baiut Mining Area, Romania

Spatial insights into microplastics and heavy metals levels, and risks in wastewater irrigated surface soils of Okara, Pakistan: Microplastics sizes impacts on heavy metals distribution using Structure equation model.

Pakistan's freshwater shortage and climate events have caused soil nutrient leaching, prompting cities to adopt wastewater irrigation. This study investigates wastewater as a potential source of microplastics (MPs) and heavy metals (HMs), assessing contaminant levels in wastewater-irrigated surface soils (WISS) in district Okara, Pakistan. It further explores potential ecological and human health risks associated with HMs in soil and the impact of MPs on HMs distribution and physicochemical properties. The concentrations of HM in WISS were within permissible limits (Cd: 0.48, Cu: 17.99, Zn: 29.73, Pb: 19.65, Fe: 8559.5), except for Mn, which was 182.94 mg/kg. MPs abundance ranged from 1850 to 5300 particles/kg, with the most common physical characteristics being fragment shapes (49.6%); black color (40.1%), and small sizes (<500 μm) many physical properties depicted association with HMs and MPs sizes. The structural equation model (SEM) showed a significant impact of MPs on HMs distribution, risk index, and pollution load index, but no significant relationship with physicochemical properties. The pollution indices for HMs in WISS indicated low ecological risk and negligible non-carcinogenic health risks were predicted for both adults and children. However, regular monitoring, enforcement of management and implementation plans, and remediation strategies for HMs and MPs in WISS are highly recommended.

Synchrotron-based correlative imaging of metals and proteins in neuronal cells: state of the art and future challenges in neurometallomics.

Metal homeostasis in the nervous system is subtly regulated and changes in metal distribution or content, either increases or decreases, are associated with neurodegeneration or cognitive impairment. Determining the localisation and quantification of metals in different types of neurons is important information for understanding their role in neurobiology. Synchrotron X-ray fluorescence imaging is a powerful technique that provides very high sensitivity and high spatial resolution for imaging metals in cells. However, additional biological information is often required to correlate the subcellular localisation of metals with specific proteins or organelles. The purpose of this article is to review the studies in neuroscience that correlate metal imaging by synchrotron X-ray fluorescence with protein localisation by other techniques. The article highlights the diversity of correlative modalities that have been used, from fluorescence to super-resolution and infrared microscopy, the wealth of information that has been extracted, but also discusses some current limitations. Future developments are needed, particularly for direct imaging of metals and proteins with a single instrument.

Probing cosmic chemical enrichment with next-generation gravitational-wave observatories

Abstract By observing binary black hole (BBH) mergers out to the edge of the Universe, next-generation (XG) ground-based gravitational-wave (GW) detectors like Cosmic Explorer and Einstein Telescope will map the BBH merger rate across all of cosmic history. &amp;#xD;This merger rate traces the formation rate of their progenitor stars convolved with a delay time distribution. &amp;#xD;Given theoretically-motivated priors on the delay time distribution, we show how XG observations can measure the BBH progenitor formation rate, probing the star formation rate (SFR) up to $z &gt; 15$. &amp;#xD;However, the progenitor formation rate does not directly give a measurement of the SFR, but rather a combination of the SFR and its metallicity distribution as a function of redshift. &amp;#xD;Fortunately, the metallicity-dependence of BBH formation likely varies as a function of BBH mass and/or formation channel. &amp;#xD;We find that if different BBH subpopulations with distinct metallicity biases can be identified, comparing their rates as a function of redshift yields a simultaneous measurement of the SFR and its metallicity distribution. Given optimistic theoretical priors and one year of observation, this may provide a $\sim10\%$ measurement of the SFR at its peak and a 0.2 dex (0.7 dex) measurement of the median metallicity out to $z = 10$ ($z = 15$) at 90\% credibility, although the uncertainties scale with theoretical uncertainties on BBH delay times and formation efficiencies.

Groundwater Contamination: Study on the Distribution and Mobility of Metals and Metalloids in Soil and Rocks

This study investigates the distribution and mobility of metals and metalloids (M&amp;Ms) in soils, rocks, and groundwater within the geologically complex southwestern region of Sicily. The study aims to highlight how natural sources, like rocks and soils, can release elements potentially harmful to human health. It underlines their dual role as both natural reservoirs and active sources of M&amp;M release, driven by leaching processes influenced by physicochemical factors such as pH and redox potential (Eh). Lithological characteristics significantly influence the retention and release of elements, with clay-rich formations exhibiting higher immobilization capacity. However, environmental parameter variations can enhance element mobilization, increasing bioavailability and the risk of groundwater contamination. Water quality analyses reveal regulatory exceedances for As, B, Ni, and Be, underscoring potential health and ecological risks. Concurrently, microbiological investigations identify diverse microbial communities capable of altering the oxidative states of specific elements through oxidation and reduction processes, further influencing their mobility. This study underscores the importance of understanding natural sources of M&amp;Ms and their interactions with geochemical and microbiological processes for effective environmental risk assessment. The findings provide a foundation for developing integrated and sustainable water resource management strategies to mitigate contamination risks and safeguard ecosystems and public health.