Fraction Of Iron Research Articles

The solar wind heavy ion composition in the ascending phases of the solar cycles 23 and 25

The approximately 11-year solar cycle has been shown to impact the heavy ion composition of the solar wind, even when accounting for streams of differing speeds; however, the heavy ion composition observed between the same specific phases of a past solar cycle and the current cycle has rarely, if ever, been compared. Here, we compare the heavy ion composition of the solar wind, as measured in situ during the solar cycle 23 and 25 ascending phases. We examine the mean iron and oxygen charge state composition and the O7+/O6+ ratio in multiple ranges of associated bulk wind speeds. Then, we compare the iron and oxygen charge state composition and relative abundance of iron to oxygen in the traditionally defined fast and slow solar wind. Finally, to determine the impact of individual ion contributions on the solar wind iron abundance, we examine individual ratios of iron and oxygen ions. Although the charge state composition remained broadly similar between these two ascending phases, both the O7+/O6+ ratio and iron fractionation in fast-speed streams were higher in the solar cycle 25 ascending phase than they were during the solar cycle 23 ascending phase, suggesting that equatorial coronal hole fields more frequently reconnected with helmet streamers or active regions in the latter of the two ascending phases; however, more work will need to be done to connect these observations back to their coronal origins. The individual ion ratios used in this work provided a spectrum to analyze the aggregate elemental abundances, and this work, as a whole, is an important step in determining how conditions in the corona may vary between solar cycles between the same phases.

Detection and Prediction of Toxic Aluminum Concentrations in High-Priority Salmon Rivers in Nova Scotia.

Elevated concentrations of toxic cationic aluminum (Ali) are symptomatic of terrestrial and freshwater acidification and are particularly toxic to salmonid fish species such as Atlantic salmon (Salmo salar). Speciated metal samples are rarely included in standard water monitoring protocols, and therefore the processes affecting Ali dynamics in freshwater remain poorly understood. Previous analysis of Ali concentrations in Nova Scotia (Canada) rivers found that the majority of study rivers had concentrations exceeding the threshold for aquatic health, but a wide-scale survey of Ali in Nova Scotia has not taken place since 2006 (Dennis, I. F., & Clair, T. A., 2012, Canadian Journal of Fisheries and Aquatic Sciences, 69(7), 1174-1183). The observed levels of dissolved aluminum in Atlantic salmon (Salmo salar) rivers of Atlantic Canada have potential serious and harmful effects for aquatic populations. We present the findings of the first large-scale assessment of the Ali status of Nova Scotia rivers in 17 years; we measured Ali concentrations and other water chemistry parameters at 150 sites throughout the Southern Uplands region of Nova Scotia from 2015 to 2022. We found that Ali concentrations exceeded toxic thresholds at least once during the study period at 80% of the study sites and that Ali concentrations increased during the study period at all four large-sample study sites. Modeling of relationships between Ali concentrations and other water chemistry parameters showed that the most important predictors of Ali are concentrations of the dissolved fractions of Al, iron, titanium, and calcium, as well as dissolved organic carbon and fluoride. We developed a fully Bayesian linear mixed model to predict Ali concentrations from a test data set within 15 μg/L. This model may be a valuable tool to predict Ali concentrations in rivers and to prioritize areas where Ali should be monitored. Environ Toxicol Chem 2024;00:1-12. © 2024 The Author(s). Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Practical experience to theoretical innovation: A model for recovering metal resources from industrial solid waste − A case study of copper smelting slag

Industrial solid waste (ISW), a byproduct of modern industrial production, poses significant challenges to sustainable development due to limitations in economic and technical capabilities. Despite containing valuable metal resources, the lack of a coherent approach to its treatment has hindered progress in addressing this longstanding issue. In response, we introduce an innovative model for metal resource recovery from ISW (ISWMRR), with a specific focus on copper smelting slag (CSS) as a prevalent example. This study underscores the efficacy of mineral phase reconstruction technology in converting CSS from a liability to an asset, thereby ensuring a sustainable stream of high-quality raw materials for green steel production amid declining iron ore reserves. Experimental findings indicated that employing the ISWMRR model enabled the successful production of iron products from CSS, yielding an iron concentrate with a TFe (total iron) fraction of 87.21 wt% and iron recovery of 91.24%. This approach facilitated the cost-effective, environmentally friendly, and efficient recovery of iron resources from CSS. By furnishing a novel theoretical framework, our research seeks to guide scientists and industry stakeholders engaged in ISW management.

Nasal exudate for diagnosis of stroke: fundamental studies through iron fractionation, total iron, and targeted protein determinations

During the last years, there has been an increasing research interest in the analysis of biological fluids requiring non-invasive sampling for biomedical and clinical applications. In this work, we have focused on the nasal exudate with the aim of investigating the potential use of this fluid to know the role of iron in stroke and also for diagnosis. Potential differences in the nasal exudate, collected in swabs, from diagnosed hemorrhagic stroke, ischemic stroke, and control groups were investigated with regard to total iron by inductively coupled plasma-mass spectrometry, iron fractionation studies by size exclusion chromatography together with post-column isotope dilution analysis, and four proteins containing iron (ferritin, transferrin, lactoferrin, and ferroportin) with ELISA kits. All these analyses represent an analytical challenge, considering the rather limited amount of sample (10–40 mg) available, being the nasal exudate extracted from the swab with 300 µL 10 mM Tris/HCl, pH = 7.4. Studies to obtain reliable analytical information, such as the blank contribution of the sampling step, evaluation of the extraction efficiency of the nasal exudate from the swab, and normalization strategies for data treatment, have been carried out. Results showed that despite the limited number of investigated samples, fractionation studies as well as the concentrations of ferritin and ferroportin obtained with ELISA kits showed a differential behavior between the different cohorts.

20th century climate warming and human disturbance triggered high aquatic production and strong water-column mixing in maar Lake Xiaolongwan, northeastern China

Lake ecosystems in northeastern (NE) China are sensitive to global environmental change, and are currently under threats of eutrophication and hypolimnetic anoxia. However, the lack of long-term records of lake production and anoxia in this region makes it difficult to discriminate the impacts of recent anthropogenic activity on lake ecosystems from natural ecosystem variability. This study investigates varved sediments from remote maar Lake Xiaolongwan, NE China and reconstructs high-resolution changes in lake primary production, anoxia, nutrient cycling and catchment processes over the past 1500 years using hyperspectral imaging inferred sedimentary total chlorophyll-a and bacteriopheophytin-a (Bphe-a), combined with sedimentary iron and phosphorus fractions data. Results show that, prior to discernible human impacts in this area from ∼600 CE to 1900 CE, lake primary production was higher during warm periods and reduced during cold periods. Bphe-a records show that hypolimnetic anoxia persisted regardless of temperature variability. Cluster analysis suggests that lake algal communities and biogeochemical conditions in the twentieth-century warm period are unprecedented and significantly different from any other time over the past 1500 years. This phenomenon mostly results from global warming and stronger local catchment disturbance in the early 1900s, combined with atmospheric pollution after the 1950s. Human-driven climate warming has caused stronger seasonal mixing (due to shortened ice-cover duration) and overall better oxygenation in the lake. This study demonstrates clear anthropogenic impacts to lake ecosytems in a relatively pristine region in NE China. We anticipate that our findings will have implications for understanding the status of aquatic ecosystems in NE China under future interacting stressors of anthropogenic climate warming and pollution.

Assessing the efficacy of some heavy-metal infused concrete mixtures in gamma-ray and neutron shielding applications

This study examines the radiation shielding properties of sixteen diverse concrete types encompassing both gamma-ray and neutron radiation. Concrete, a widely used material due to its low cost, high density, and efficient shielding capabilities, is investigated to determine how its varying compositions impact its ability to attenuate ionizing radiation. Utilizing the Phy-X/PSD software, the research analyses key parameters like mass attenuation coefficients, linear attenuation coefficients, and half-value layers, among others, to assess each concrete type's shielding efficiency. The findings reveal that concretes containing heavy metals such as iron and barium exhibit enhanced performance in absorbing photons, thus providing superior protection against radiation. Iron-Portland concrete demonstrated a high density of 5.80 g/cm³ and exhibited a mass attenuation coefficient (MAC) of 35.14 cm2/g at 0.1 MeV, significantly higher than MAC of ordinary concrete (i.e., 17.24 cm2/g). Significantly, Iron-Portland and Barite Concrete are highlighted for their exceptional shielding abilities, with Iron-Portland showing a fast neutron removal cross-section (ΣR) of 14.29 cm−1, compared to 11.11 cm−1 for ordinary concrete. It can be concluded that the high elemental mass fraction of iron (88.12 wt%) in Iron-Portland concrete, along with its significant density of 5.80 g/cm3, makes it the most advantageous for gamma-ray and neutron shielding applications due to its superior absorption and attenuation capabilities.

Iron toxicity in lowland rice influenced by application of high potassic fertilizer with suitable cultivars enhanced productivity and climate resilience

Iron poisoning in low-land rice in India develops gradually and is primarily caused by anaerobic conditions in submerged rice fields. A high concentration of ferrous ions in the soil solution disrupts the potassium balance in rice plants, leading to adverse effects on crop growth. In the 2021–2022 period, an experiment was conducted in non-saline, iron-rich soil (pH–4.82, Fe–458.6 mg kg–1) to mitigate iron toxicity in rice cultivars through potassium nutrition. The experiment involved 4 potassium application doses (K-40, K-80, K-100 and K-120) and 32 rice cultivars, replicated twice using a split-plot design. Higher potassium doses led to increased tiller counts, but gradually decreased root length. Notably, cultivars like Kanchan, Indravati, Jagabandhu, Santepheap and Salibahan exhibited the lowest iron concentration in their grains compared to susceptible cultivars. Administering K-120 resulted in a yield increase of over 36.70 q ha-1. Grain yield increased with higher K dosage, although it did not affect total iron content. However, K doses did influence specific fractions of iron in the soil. Hence, potassium nutrition appears crucial in managing iron toxicity in inceptisols, especially when paired with cultivars tolerant to iron toxicity.

Nature and evolution of lithospheric mantle beneath the Northeast China: Constraints from the Houtuancun mantle xenoliths

Mantle xenoliths entrained in a newly discovered Cenozoic basalt at Houtuancun within the Yilan-Yitong fault zone, situated beneath the Xing'an Mongolian Orogenic Belt in Northeast China, provide a unique opportunity to constrain the nature and evolution of the lithospheric mantle beneath this region. The mantle xenoliths are predominantly spinel lherzolite, with rare occurrences of harzburgite, wehrlite, and websterite. The Houtuancun spinel lherzolite and harzburgite are characterized by high forsterite contents in olivines (89.3–91.1), and their clinopyroxene rare earth element patterns range from slightly light rare earth element (LREE)-depleted to LREE-enriched, reflecting variable degrees of partial melt extraction (up to 20%) overprinted by later metasomatism. Despite this, the Fe isotopic composition of the Houtuancun lherzolite and harzburgite exhibits little variation (δ57/54Fe = −0.05–0.09‰), with an average of 0.02 ± 0.09‰ (2SD, n = 9), close to the suggested δ57/54Fe value of 0.04 ± 0.04‰ for the upper mantle, and there is no significant inter-mineral disequilibria. In contrast, the wehrlite has a slightly lower Mg# [=100 ╳ Mg2+/(Mg2+ + Fe2+)] (88.4) and δ57/54Fe (−0.05‰) compared to the spinel lherzolite and harzburgite, reflecting kinetic iron fractionation during melt-rock interaction. The websterite exhibits the lowest MgO (20.6–24.8 wt%), highest Al2O3 content (5.8–7.3 wt%), and the highest δ57/54Fe (0.25–0.28‰) among the studied xenoliths, suggesting an episode of subduction-related silicate melt circulation through the upper mantle. The results demonstrate compositional heterogeneity of the mantle beneath the Xing'an Mongolian Orogenic Belt in Northeast China. The observed heterogeneity may result from a combination of varying degrees of melt extraction of the subcontinental lithospheric mantle and metasomatism by melts related to the subduction of the (Paleo)-Pacific plate.

THE ROLE OF ATOMIC SCATTERING FACTORS IN DETERMINING THE MINERAL COMPOSITION OF THE BAZHENOV SUITE'S ROCKS

For the first time, it was demonstrated, that the use of standard atomic-structural parameters of minerals in X-ray diffraction (XRD) analysis to determine the phase composition in the Bazhenov suite's core is incorrect and most often leads to inaccurate information when calculating their quantitative ratio. In particular, by decomposing the XRD — based quantitative data on the mineral composition of the core of the Bazhenov suite into the main rock-forming oxides and further comparing them with reliable X-ray fluorescence spectrometry (XRF) data, an unsatisfactory convergence between them was established. At the same time, significant differences in the results of XRD and XRF have been shown in terms of oxides of silicon, sodium, magnesium, potassium, and iron, both at large and small mass fractions. It has been found that even with perfect XRD, achieved by optimizing the standard mineral structure parameters (lattice period, crystallite size, crystal lattice microdistortion, absorption coefficient, crystallographic texture, background) and achieving a very high degree of convergence (more than 95%) of experimental and theoretical diffractograms, the differences between oxide forms are still significant. It is shown, that the results of XRD of Bazhenov suite are questioned due to detected inconsistencies in oxide forms. Using the analysis of multiple factors and data from diffractograms of many samples, it has been established that the identified differences are primarily caused by the use of incorrect initial atomic-structure parameters of minerals in modeling. It is shown that rock minerals in the Bazhenov suite are primarily characterized by significant changes in the values of atomic scattering factors and significant displacements of atomic positions in the nodes of the crystal lattice, caused by the action of the high pressures and temperatures in the formation. For the first time, the XRD algorithm that has been developed, is presented and implemented in Bazhenov suite rocks, with consideration of the state of atoms in the analyzed mineral. Furthermore, it was found that the authors XRD approach enables the identification and quantification of the Bazhenov suite minerals with a relatively low content, which are challenging to identify during traditional XRD.

Liver steatosis in patients with transfusion-dependent thalassaemia.

We evaluated the prevalence and the clinical associations of liver steatosis (LS) in patients with transfusion-dependent thalassaemia (TDT). We considered 301 TDT patients (177 females, median age = 40.61 years) enrolled in the Extension-Myocardial Iron Overload in Thalassaemia Network, and 25 healthy subjects. Magnetic resonance imaging was used to quantify iron overload and hepatic fat fraction (FF) by T2* technique and cardiac function by cine images. The glucose metabolism was assessed by the oral glucose tolerance test (OGTT). Hepatic FF was significantly higher in TDT patients than in healthy subjects (median value: 1.48% vs. 0.55%; p = 0.013). In TDT, hepatic FF was not associated with age, gender, serum ferritin levels or liver function parameters, but showed a weak inverse correlation with high-density lipoprotein cholesterol. The 36.4% of TDT patients showed LS (FF >3.7%). Active hepatitis C virus (HCV) infection, increased body mass index and hepatic iron were independent determinants of LS. A hepatic FF >3.53% predicted the presence of an abnormal OGTT. Hepatic FF was not correlated with cardiac iron, biventricular volumes or ejection fractions, but was correlated with left ventricular mass index. In TDT, LS is a frequent finding, associated with iron overload, increased weight and HCV, and conveying an increased risk for the alterations of glucose metabolism.

METAL-Z: Measuring Dust Depletion in Low-metallicity Dwarf Galaxies

The cycling of metals between interstellar gas and dust is a critical aspect of the baryon cycle of galaxies, yet our understanding of this process is limited. This study focuses on understanding dust depletion effects in the low-metallicity regime (<20% Z ⊙) typical of cosmic noon. Using medium-resolution UV spectroscopy from the Cosmic Origins Spectrograph on board the Hubble Space Telescope, gas-phase abundances and depletions of iron and sulfur were derived toward 18 sight lines in local dwarf galaxies IC 1613 and Sextans A. The results show that the depletion of Fe and S is consistent with that found in the Milky Way (MW), LMC, and SMC. The depletion level of Fe increases with gas column density, indicating dust growth in the interstellar medium. The level of Fe depletion decreases with decreasing metallicity, resulting in the fraction of iron in gas ranging from 3% in the MW to 9% in IC 1613 and ∼19% in Sextans A. The dust-to-gas and dust-to-metal ratios (D/G, D/M) for these dwarf galaxies were estimated based on the MW relations between the depletion of Fe and other elements. The study finds that D/G decreases only slightly sublinearly with metallicity, with D/M decreasing from 0.41 ± 0.05 in the MW to 0.11 ± 0.11 at 0.10 Z ⊙ (at log N(H) = 21 cm−2). The trend of D/G versus metallicity using depletion in local systems is similar to that inferred in Damped Lyα systems from abundance ratios but lies higher than the trend inferred from far-IR measurements in nearby galaxies.

Investigation of a haze-to-dust and dust swing process at a coastal city in northern China part II: A study on the solubility of iron and manganese across aerosol sources and secondary processes

The soluble fractions of iron (FeS) and manganese (MnS) in atmospheric aerosols potentially impact human health and ocean ecosystems. This study investigated a persistent haze-to-dust process observed in winter Qingdao, a coastal city in Northern China, focusing on the aerosol sources and acidification process affecting the dissolution of Fe and Mn. It was found that FeS in PM2.5 peaked during the intermingling of dust plumes with local haze, while other species of Fe and Mn reached their maximal levels coinciding with PM10. Positive Matrix Factorization (PMF) analysis determined that aged dust was the main source of FeS in PM2.5, accounting for 44.0%, while fresh dust contributed just 1.9%. Conversely, fresh dust played a more significant role in PM10, contributing 8.9% to FeS. Similar trends were observed in the initial dust and dust swing periods, aged dust was the dominant contributor to FeS, but fresh dust accounted for a higher fraction in PM10 (11.5%) than in PM2.5 (4.9%). In contrast, MnS levels, with high solubility (%MnS), were mainly from fresh dust (27.9% and 63.2% in PM2.5 and PM10, respectively). The PMF estimated %MnS in fresh dust at 17.0% for PM2.5 and 19.4% for PM10, considerably higher than Fe solubility (%FeS) at 0.3% and 0.1% in the corresponding particulate sizes. Additionally, %FeS correlated more strongly with sulfate and nitrate per unit Fe mass (R2 = 0.68 and 0.79 in PM2.5 and PM10) than %MnS (R2 = 0.49 and 0.50), suggesting a more profound impact of acidification on Fe dissolution. Further analysis suggests liquid water content rather than pH played a more critical role during the acidification process within fine particles. This study successfully estimated the solubility of Fe and Mn within various aerosols, providing valuable information and advancing our understanding of their dissolution and potential health and ecosystem impacts.

NixFe100-x for urea and oxygen evolution: a matter of compromise

The combination of aqueous electrolysis, either for hydrogen generation or CO2 conversion, with wastewater treatment offers an elegant way to tackle issues associated with our energy transition and the need for clean drinking water. However, it requires an anode capable of doing both the oxidation of the targeted pollutant and the oxygen evolution reaction (OER), as most pollutants are present in too low concentration to be practical for industrial electrolysis. In this study, we focussed on the oxidation of urea on NixFe100-x catalysts. These catalysts were prepared by pulsed laser ablation in liquid, a versatile and green technique to prepare electrocatalysts. Transmission electron microscopy of the nanoparticles indicates the production of monodisperse nanoparticles, with an average diameter increasing from 7.8 ± 2.8 to 19.7 ± 3.9 nm with a higher iron fraction. The composition could be controlled between pure Ni and NiFe bimetallic nanoparticles with up to 56 ± 3% of iron, by controlling the composition of the target. A brief optimisation of the electrode preparation (loading, catalyst-to-carbon ratio) yielded an optimum at about 30 µg/cm2 of catalyst with a catalyst-to-carbon ratio of 20:80. During the electrocatalytic tests, Ni was the best catalyst for urea oxidation, with a maximum peak current of 619 mA/mg. However, Ni75Fe25 was the best OER catalyst, showing a peak current of 1150 mA/mg. The difference increased further during CA at 0.5 V, during which Ni75Fe25 outperformed pure Ni by almost a factor of 3 after 30 min.

Cu fate driven by colloidal polystyrene microplastics with pipe scale destabilization in drinking water distribution systems

Microplastics (MPs) and Cu have been detected in drinking water distribution systems (DWDSs). Investigating MP effects on Cu adsorption by pipe scales and concomitant variations of pipe scales was critical for improving the water quality, which remained unclear to date. Therefore, polystyrene microplastics (PSMPs) were adopted for the model MPs to determine their effects on Cu fate and pipe scale stabilization, containing batch adsorption, metal speciation extraction, and Cu release experiments. Findings demonstrated that complexation and electrostatic interactions were involved in Cu adsorption on pipe scales. PSMPs contributed to Cu adsorption via increasing negative charges of pipe scales and providing additional adsorption sites for Cu, which included the carrying and component effects of free and adsorbed PSMPs, respectively. The decreased iron and manganese oxides fraction (45.57 % to 29.91 %) and increased organic fraction (48.51 % to 63.58 %) of Cu in pipe scales when PSMPs were coexisting illustrated that PSMPs had a greater affinity for Cu than pipe scales and thus influenced its mobility. Additionally, the release of Cu could be facilitated by the coexisted PSMPs, with the destabilization of pipe scales. This study was the first to exhibit that Cu fate and pipe scale stabilization were impacted by MPs, providing new insight into MP hazards in DWDSs.

Ferroptosis affects cognitive dysfunction and the progression of mental illnesses

IntroductionFerroptosis is a programmed form of cell death characterized by excessive accumulation of intracellular iron fraction, uncontrolled lipid peroxidation, impairment of glutathione-dependent antioxidant functions, and loss of oxidative-antioxidant balance. Nerve cells are sensitive to excessive amounts of iron, which impairs the functioning of mitochondria and leads to their death. Ferroptosis has been identified in neurological diseases such as stroke, Alzheimer’s disease, Parkinson’s disease. Features of ferroptotic cells have been observed in models expressing cognitive deficits, and ferroptosis-related genes have been associated with the development of mental illnesses.ObjectivesThe aim of the study was to analyze the available literature on the relationship between the occurrence of ferroptosis and cognitive impairment occurring in mental diseases, such as schizophreniaMethodsThe publications found in the PubMed database were analyzed after entering the following entries: ferroptosis, mental illness, cognitive functions, schizophrenia.ResultsFerroptosis occurs in mental illnesses. Increased expression of the TP53 and VEGFA genes, which are associated with ferroptosis, has been identified in patients suffering from schizophrenia. Animal research confirms that disturbed iron homeostasis causes iron overload in nerve cells, which leads to ferroptosis and has a neurodegenerative effect, as well as deepens cognitive deficits. The use of iron chelator has a neuroprotective effect and reduces the occurrence of cognitive disorders.ConclusionsGenes associated with ferroptosis may influence the development of schizophrenia, which means that ferroptosis may be involved in the pathophysiology of schizophrenia. Excess iron inside nerve cells, as a feature of ferroptosis, may affect the deterioration of cognitive functioning. Administration of iron chelators protects neurons by reducing the toxic effects of iron.Disclosure of InterestNone Declared

Enhancing biogas production from palm oil mill effluent through the synergistic application of surfactants and iron supplements

In this study, the effects of various surfactants on the soluble chemical oxygen demand (COD) fraction and biogas production from palm oil mill effluent (POME) were investigated. A cationic surfactant (cetyltrimethylammonium bromide, CTAB) and a nonionic surfactant (Tween 80; TW80) were found to adsorb onto the particulate matter from POME, markedly reducing the soluble COD, unlike an anionic surfactant (sodium dodecyl sulfate, SDS). The mechanism underlying this phenomenon might be the adsolubilization of oil on particulate matter induced by the adsorbed surfactants. In terms of biogas production, 0.1 % w/v SDS and CTAB dramatically reduced the biogas yield, while 0.1 % w/v TW80 did not have this negative effect. A synergistic effect was observed when TW80 (0.1 % w/v) was combined with FeSO4 (400 mg/L), resulting in a 17 % greater biogas yield than that achieved with treatments using TW80 or FeSO4 alone. Moreover, the combination of TW80 and FeSO4 increased the biogas production rate. Surprisingly, the water-soluble iron fraction remained consistent across all treatments, suggesting that the adsorption of TW80 on particulate matter may limit micelle formation. Importantly, the proportion of methane in the generated biogas remained stable in all the treatments. Microbial community analysis revealed that the introduction of TW80 and FeSO4 had no discernible impact on the microbial community of the system. Pretreatment with TW80 and an iron supplement significantly enhanced biogas production and reduced the retention time of the anaerobic digestion (AD) system while maintaining the biogas quality and microbial community stability.

Mapping Dissolved Organic Carbon and Organic Iron by Comparing Deep Learning and Linear Regression Techniques Using Sentinel-2 and WorldView-2 Imagery (Byers Peninsula, Maritime Antarctica)

Byers Peninsula is considered one of the largest ice-free areas in maritime Antarctica. Since 2006, the Spanish Polar Program has taken part in a large number of environmental studies involving the effects of climate change on biological life cycles, limnology, and microbiology. Soils from maritime Antarctica are generally weakly developed and have chemical, physical, and morphological characteristics that are strongly influenced by the parent material. However, biological activity during the short Antarctic summer promotes intense transference of nutrients and organic matter in areas occupied by different species of birds and marine mammals. Mapping and monitoring those areas that are highly occupied by various species could be very useful to create models prepared from satellite images of the edaphic properties. In this approach, deep learning and linear regression models of the soil properties and spectral indexes, which were considered as explicative variables, were used. We trained the models on soil properties closely related to biological activity such as dissolved organic carbon (DOC) and the iron fraction associated with the organic matter (Fe). We tested the best approach to model the spatial distribution of DOC, Fe, and pH by training the linear regression and deep learning models on Sentinel-2 and WorldView-2 images. The most robust models, the pH model built with the deep learning approach on Sentinel images (MAE of 0.51, RMSE of 0.70, and R2 with a residual of −0.49), the DOC model built with linear regression on Sentinel images (MAE of 189.39, RMSE of 342.23, and R2 with a residual of 0.0), and the organic Fe model built with deep learning (MAE of 116.20, RMSE of 209.93, and R2 of −0.05), were used to track possible areas with ornithogenic soils, as well as areas of Byers Peninsula that could be supporting the highest biological development.

Characterization of Peat Water Electrocoagulation Flocs from Sarawak Southern Region

Sarawak located in Borneo is endowed with the vast availability of peat water sources, particularly for the state southern region. Several investigations have shown that electrocoagulation treatment with aluminium electrodes is feasible to treat peat water in which the quality is comparable to the National Water Quality Standard (NWQS). Even though electrocoagulation treatment is feasible to treat peat water, the characteristics of peat water electrocoagulation flocs have not been reported. As such, this study aims to investigate the characteristics of the electrocoagulation flocs from peat water derived from the Sarawak southern region by using batch electrocoagulation treatment. The objectives of this study are to conduct an experimental study analysis of and identify the minerals on the electrocoagulation flocs along with operating energy cost analysis of peat water batch electrocoagulation treatment. Consequently, this study has found that reaction time and current density affect the production of flocs in which the amount of flocs increases with the increasing reaction time and current density. The flocs produced are found to consist of a large fraction of oxygen (O), carbon (C), iron (Fe), and aluminium (Al) along with a small fraction of potassium (K), magnesium (Mg), calcium (Ca) and Silicon (Si). The presence of Al observed in the flocs is due to the aluminium hydroxide generated during the electrocoagulation process. The total operating cost for peat electrocoagulation with a current density of 5A and reaction time of 20 minutes is about RM0.31 per m3. As a result, the electrocoagulation of peat water process is able to treat peat water as well as produce flocs in which earth elements and heavy metals could be recovered.

Geochemical fractionation of iron in paper industry and municipal landfill soils: Ecological and health risks insights

Industrial processes and municipal wastes largely contribute to the fluctuations in iron (Fe) content in soils. Fe, when present in unfavorable amount, causes harmful effects on human, flora, and fauna. The present study is an attempt to evaluate the composition of Fe in surface soils from paper mill and municipal landfill sites and assess their potential ecological and human health risks. Geochemical fractionation was conducted to explore the chemical bonding of Fe across different fractions, i.e., water-soluble (F1) to residual (F6). Different contamination factors and pollution indices were evaluated to comprehend Fe contamination extent across the study area. Results indicated the preference for less mobile forms in the paper mill and landfill, with 26.66% and 43.46% of Fe associated with the Fe–Mn oxide bound fraction (F4), and 57.22% and 24.78% in the residual fraction (F6). Maximum mobility factor (MF) of 30.65% was observed in the paper mill, and 80.37% in the landfill. The enrichment factor (EF) varied within the range of 20 < EF < 40, signifying a high level of enrichment in the soil. The individual contamination factor (ICF) ranged from 0 to >6, highlighting low to high contamination. Adults were found to be more vulnerable towards Fe associated health risks compared to children. The Hazard Quotient (HQ) index showed the highest risk potential pathways as dermal contact > ingestion > inhalation. The study offers insights into potential Fe contamination risks in comparable environments, underscoring the crucial role of thorough soil assessments in shaping land use and waste management policies.

The Immobilization Mechanism of Inorganic Amendments on Cu and Cd in Polluted Paddy Soil in Short/Long Term.

This study investigated the impact of soil colloidal characteristics on the transfer patterns of different Cu and Cd speciation in contaminated soil treated with three different amendments: lime (L), zero-valent iron (ZVI), and attapulgite (ATP). It seeks to clarify the activation hazards and aging processes of these modifications on Cu and Cd. Compared with the control (CK), the available Cu concentrations treated with amendments reduced in the short term (6 months) by 96.49%, 5.54%, and 89.78%, respectively, and Cd declined by 55.43%, 32.31%, and 93.80%, respectively. Over a 12-year period, there was no significant change in the immobile effect with L, while Cu and Cd fell by 19.06% and 40.65% with ZVI and by 7.63% and 40.78% with ATP. Short- and long-term increases in the readily reducible iron and manganese oxide fraction of Cu and Cd were accompanied by a considerable rise in the concentrations of amorphous iron oxide in the soil and colloid after amendment treatment. This suggested that Cu and Cd were immobilized and stabilized in part by amorphous iron oxide.