High Fe Content Research Articles

Chemical features of dark miсas from calcite-nepheline-feldspar pegmatites of the Ilmenogorsky alkaline block (South Urals)

The composition and structure of micas of the annite–phlogopite and siderophyllite– eastonite series in calcite-nepheline-feldspar pegmatites of the Ilmenogorsky miaskite block are studied. The composition of mica of the annite–phlogopite series depends on the formation conditions of pegmatites. The nepheline-feldspar pegmatite with a rock-forming calcite (mine no. 125) contains annite with higher Fe content (Ftot 0.67–0.73). A pegmatite with late calcite (mine no. 16) contains less ferruginous annite (Ftot 0.52–0.63) and phlogopite (Ftot 0.32–0.50). The mica of the annite-phlogopite series exhibits a direct correlation between the Fetotal and Al contents. The mica of the siderophyllite–eastonite series in calcite-nepheline-feldspar pegmatites formed later in assemblage with minerals of the pyrochlore group, baddeleyite, calcite, fuorite, magnetite and Nb-bearing rutile. The Fe content of micas affects the shift of the Raman bands in the studied Samples. Ferruginous siderophyllite, eastonite and their barium varieties are identifed for the frst time for the Ilmenogosrky-Vishnevogorsky complex.

High-levels of toxic elements and radioactivity in an abandoned sulphur mine: Insights on the origin and associated environmental concerns

Natural fibrous epsomite crystals containing high amounts of toxic and radioactive elements have recently been discovered in the abandoned sulphur mine of Perticara (Italy). In the present study, all the different matrices that characterize the Perticara mine (air, water, host-rock, minerals, and bitumen) were sampled and investigated employing a multi-analytical approach to define the distribution and origin of these hazardous elements. Water samples showed high Al, Fe, Pb, Mg, and Mn content but not radioactive elements. The bitumen sample showed a higher amount of 210Po and 210Pb (0.12 Bq/g and 0.11 Bq/g, respectively), compared to the host-rock and fibrous sericolite samples, but lower than fibrous epsomite crystals (210Po 5.59 Bq/g; 210Pb 5.93 Bq/g). A high 222Rn concentration was also detected in the tunnels and it is likely the source of both 210Po and 210Pb, which are in radioactive equilibrium, especially in epsomite. This latter mineral, being capable of capturing 210Po and 210Pb, can be used as a helpful mineral indicator for the presence of radioactive elements in similar environmental conditions. Moreover, our results also highlight a slight anomaly in the 40K and 226Ra content of the host-rock, probably derived from the evaporitic sediments of the rock succession. The current risk for humans linked to the mine environment is minor since the activity of the mine ended several decades ago. However, the results of this study must be taken into serious consideration for any future development of this area (e.g., industrial archaeology, farming, educational, scientific and touristic purposes), and represent the basis for the calculation of radiotoxicity and dose assessment, which is fundamental for the correct and safe management of the mining environment and neighbouring areas.

Effect of Fe-loading in iron-based catalysts for the CH4 decomposition to H2 and nanocarbons

The catalytic CH4 decomposition (CMD) over Fe-based catalyst is an economical and environmentally friendly way to produce Cox-free H2 and carbon nanotubes (CNTs). The Fe-loading was varied to study its influence on the catalytic performance. The highest H2 yield (82.25%) was obtained with a 12% Fe content where the activity of the catalyst did not decrease for 3 h on-stream. A higher Fe content causes the Fe dispersion to decrease, resulting in a reduced available surface area of active sites. Different techniques were used to characterise the fresh and spent catalysts i.e., ICP-AES, XRD, H2-TPR, SEM, TEM, and Raman spectroscopy. Plotting kinetic results as a function of 1/T, defines two different conversion ranges, being reaction rate controlled at low temperature and diffusion rate controlled at high temperature. For the reaction rate controlled regime, the Arrhenius equation provides an activation energy of 101.26 kJ/mol (Ea) and a pre-exponential factor of 393 kmol/s (A).

Corrosion of reduced activation ferritic-martensitic steel – Tungsten brazed joints in liquid lithium

Brazed joints between tungsten and steel are the essential part of the divertor armor block. Meanwhile, liquid Li is considered as a prospective coolant and plasma facing material. Therefore, it is important to estimate the corrosion rate of the brazed seam. Corrosion mechanism in liquid Li at 600 °C after 100 h exposure investigated on two types of brazed joints: with Cu and with TiZrBe filler metals. Severe corrosion damage and corrosion failure occur on the brazed seam with Cu filler. Corrosion primarily affects Cu phases in brazed seam. The brazed joint with TiZrBe filler metal shows high corrosion resistance. Results of chemical analysis indicates that corrosion products deposited on specimen surface contain high Fe and Cr content. The corrosion mechanism is similar to corrosion of steel. Corrosion in liquid Li causes preliminary dissolution of Cr-containing phases.

Simultaneous quantification of Gadoxetic acid and Cisplatin in hepatocellular carcinomas using laser ablation-inductively coupled plasma-mass spectrometry.

The gadolinium-based contrast agent Gadoxetic acid and the platinum-based antitumor agent Cisplatin were quantitatively imaged in liver and liver cancer (hepatocellular carcinoma, HCC) tissue of rats by means of laser ablation-inductively coupled plasma-mass spectrometry. HCC bearing rats simultaneously received a tail vein injection of the hepatocyte-specific magnetic resonance imaging contrast agent Gadoxetic acid and a transarterial injection of Cisplatin 15min before sacrifice and liver removal. Resecting HCC with adjacent liver tissue allows the comparison of Gd, Pt, and endogenous elements like Fe, Cu, and Zn in the various tissue types. Region of interest analysis reveals lower concentrations of Gd in HCC and higher Gd content in the adjacent liver, fitting the selective uptake of Gadoxetic acid into hepatocytes. Furthermore, two malignancy grades and their possible impact on the Gadoxetic acid and Cisplatin uptake are compared. For this, four high grade (G3) and two moderate grade (G2) HCCs were analysed, including a control sample each. Gd concentrations were lower in HCC irrespective of the grade of dedifferentiation (G2, G3) compared to adjacent liver. Despite local arterial Cisplatin injection, concentrations of Pt were similar or also reduced in HCC compared to liver tissue. In addition, endogenous Fe, Cu, and Zn were quantified. While Zn was homogenously distributed, higher Fe concentrations were determined in liver tissue compared to HCC. Hotspots of Cu suggest a deregulated copper homeostasis in certain liver lesions. The Gd and Fe distributions are compared in detail with cellular alterations examined by hematoxylin and eosin staining.

Ferric iron in chrome-bearing spinels: implications for microprobe correction procedures

AbstractWe investigated the compositions of a suite of 361 chrome-bearing spinels from spinel peridotites, ophiolitic mantle chromitites and from layered igneous intrusions in which the Fe2+/Fe3+ ratio has been determined by Mössbauer spectroscopy. We explore the crystal-chemical controls on the distribution of Fe3+ and on mineral stoichiometry with regard to electron-probe correction procedures for estimating Fe3+ in spinel. We find that chrome-bearing spinels can be subdivided into three groups: a Cr–Al-rich group; a high-Fe group; and a highly oxidised group. Spinels of the Cr–Al group are found in spinel peridotites and ophiolitic mantle chromitites. They are normal spinels with a low Fe3+ content and compositions that are close to stoichiometric. Spinels in the high-Fe group are found in layered igneous intrusions. They are also normal spinels which have higher concentrations of Fe3+ on the octahedrally coordinated site than is found for the Cr–Al group. Stoichiometric calculations tend to overestimate the Fe3+ content and their compositions do not conform to the MgO–cr# correlation found in the Cr–Al group. Spinels in the highly oxidised group are found in layered intrusions and ophiolitic mantle chromitites. They have (Fe3+/ΣFe)Möss > 0.4 and high Cr (cr# > 0.5), but relatively low Fe2+ (fe# 0.24–0.56). Stoichiometric calculations tend to underestimate the Fe3+ content. They represent normal spinels in which tetrahedrally coordinated Fe2+ has been oxidised to Fe3+.Our data show that spinels with greater Cr and Fe are sufficiently different in their crystal chemistry from the aluminous spinels to indicate that the EPMA correction procedures developed for Fe3+ in aluminous spinels on the basis of the Cr/Al ratio, and used in oxy-thermobarometry, are inappropriate for Cr-rich and Fe-rich compositions.

Tolerance of Al–Mg–Si Wrought Alloys for High Fe Contents: The Role of Effective Si

Aluminum scrap is often contaminated with steel parts, leading to accumulation of Fe in recycled Al alloys. Consequently, low limits for Fe in Al wrought alloys are difficult to meet by recycling without dilution with primary Al. Wrought alloys with a higher tolerance for Fe could help overcome this problem and improve the sustainability of Al wrought products. Here we study the effects of increasing the Fe content in EN AW-6060, 6005A, and 6082 from 0.2 to 0.7 wt pct. The microstructure and mechanical properties of the alloys after extrusion and artificial ageing are compared to the standard alloys. We found that 6082 is more tolerant to above-standard Fe contents than 6005A, which in turn is more tolerant than 6060: the strength of the 6082-based alloy with increased Fe content is comparable to that of standard 6082 and the elongation at break is increased. In contrast, the artificial ageing potential of the 6060-based alloy with more Fe is drastically reduced compared to 6060. This data and literature values show that the effective Si content is a good overall predictor of alloy strength. Effective Si is not bound in AlFeSi-type phases and is available for precipitation hardening. Additional effects of increased Fe levels are discussed.

Magnetic Susceptibility and Hydrogen Cyanide Levels as Proxy Indicator for Gold Mining Pollution in River Sediment

Sumbawa’s Kuris River is one of the rivers contaminated by the island’s traditional gold mine. In order to detect contaminant levels, we examine the magnetic susceptibility, HCN levels, and the heavy metal contents on the river’s surface sediment. Environmental pollution has been widely assessed using a combination of magnetic properties and geochemical analysis. The goals of this research are to discover how magnetic susceptibility (χ) can be used as a first-order proxy for pollution. The relation between susceptibility and HCN is of particular interest, as this is a major contaminant associated with gold mining. The surface sediment samples were collected at ten different locations along the rivers. The magnetic susceptibility was determined using the Bartington MS2B, and the hydrogen cyanide (HCN) concentration was determined using Argentometric titration. The element content was determined by an Atomic Absorption Spectrometer (AAS). The low-frequency magnetic susceptibility (χlf) ranges from 71 to 115×10-8 m3/kg, with an average of 97×10-8 m3/kg, and the χfd(%) analysis ranges from 2% to 4%. The presence of spherical iron oxides, which are indicative of combustion byproducts, was also confirmed by SEM. The samples have low magnetic susceptibility but high levels of Hg and HCN. AAS results showed high Fe, Zn, and Cu concentrations in river sediments, with more variable concentrations of Hg, Mn, As, Cr, and Au. Because Fe, Cu, As, Hg, and HCN have a significant Pearson’s correlation with χfd(%), this parameter can be a useful indicator for contamination caused by gold mining waste.

Failure Analysis of Galvanized Iron Pipe at Perumda Tirta Kanjuruhan

The most commonly used type of water pipe is iron pipe or commonly called Galvanized Iron pipe. The disadvantage of GI pipe is that it rusts easily. So it can result in degradation, decreased efficiency and construction, poor water quality, and higher maintenance costs. Water channeled through rusty pipes will pollute the water and adversely affect the health of those who consume it. This study aims to determine the factors causing failures of GI pipe in the distribution pipeline that have failed due to corrosion. The tested pipes is 1/2"ᴓ sized, 5-year-old corroded pipe whose distribution uses a gravity system and a pumping system. To support this analysis, operational data on fluid and environmental conditions around the pipeline are needed, observations on macro and micro structures, and hardness testing. The corrosion rate is calculated through the thickness loss method and the corrosion rate in the gravity system is 0.153 mm / year that higher than pipe in pumping system. Microstructure observations support the characterization of the material that this pipe is a mild steel, where this type of steel has a high Fe content so it is vulnerable to corrosion attacks. Rockwell hardness testing showed that the corrosion rate is directly proportional to the hardness value of the pipeline. The results of the analysis show that the environment around the pipe which has low soil resistivity and high humidity levels is the main factor in the occurrence of uniform corrosion of the pipe. The selection of inappropriate materials is also supportive as the cause of corrosion occurring.

Heavy metals concentration in zooplankton (copepods) in the western Bay of Bengal.

Along the coastline, urbanisation and industrialization pose significant challenges to marine habitats and biodiversity. Most wastewater that reaches the marine environment contains toxic metals, which, as they are non-biodegradable, accumulate in the biota and enter the marine food chain. This study presents the concentration of nine heavy metals (Fe, Zn, Cu, Co, Cr, Mn, Ni, Pb, and Cd) in zooplankton (copepods) during the Spring Intermonsoon/Pre-Monsoon (April 2019) in the western Bay of Bengal (BoB). Higher Fe concentrations were found in copepods both nearshore (42,352µg/g) and offshore (9835µg/g). However, the relative amounts of heavy metals in copepods from 16 locations (eight nearshore and eight offshore) varied in the order of Fe > Zn > Cu > Co > Cr > Mn > Ni > Pb > Cd. The copepods in the nearshore locations had higher concentrations of heavy metals than those offshore. Compared to earlier data on heavy metals, particularly those that are physiologically non-essential and toxic, the current study demonstrates higher amounts of these metals in copepods in the inshore BoB [Ni (avg. 58.7 ± 5.5µg/g), Pb (avg. 25.6 ± 4.7µg/g), and Cd (avg. 16.4 ± 0.9µg/g)]. Considering the strong East India Coastal Currents in the western BoB, trace metal-concentrated copepods could be transported too far along the Indian coastline from the current study area.

Test of Acceptance and Fe Levels of Green Beans with the Addition of Katuk Leaves “PUCAHITUK” as a Teenager Snack to Prevent Less Blood

According to (WHO, 1992) anemia is a condition where the Hb level is lower than the normal limit. The purpose is to determine the acceptability and levels of iron in processed mung bean pudding products with the addition of katuk leaves as a source of iron snacks for adolescents. This research method is experimental. Data collection is obtained from organoleptic tests and Fe levels in the laboratory. Statistical analysis used the Kruskall Wallis and Mann Whithney test. The results showed organoleptic properties, the most preferred formulation by the panelists was the PKU formulation with a ratio (80:30). The highest Fe content in the control code was PKA at 18.91 mg/kg. Nutritional Adequacy Ratio recommends intake of 16 mg of Fe per day as a dietary effort to prevent anemia. If the snack is given 2 times with a portion of 10% of daily needs = 10% x 16 mg = 1.6 mg. Meanwhile, the Fe content of PUKAHITUK Pudding was <0.028 mg/kg. If the green bean pudding and katuk leaves weigh 90 g/cup, they contain 90gr/1000 x < 0.028 mg = 0.0252 mg/cup. It can be concluded that 1 cup of pudding does not meet the snack needs for teenagers.

IRON-ZINC BASED GENETIC DIVERSITY ASSESSMENT IN MAIZE (ZEA MAYS L.) GENOTYPES

Hidden hunger is one of the most important challenges of the current era, and genetic biofortification is the most feasible, cheapest, and sustainable way to provide a balanced diet to the community. Given the value of biofortification in food grains, the relevant study sought to screen maize inbred lines for kernel Fe and Zn contents and estimate their bioavailability using molar ratios. One hundred maize inbred lines planted during spring 2018 in soil contained optimal levels of Fe and Zn. Maize genotypes evaluation comprised plant height, days to tasseling, silking, maturity, cob length, number of rows per cob, grains per row, grains per cob, 100-grain weight, grain yield per plant, grain Fe, Zn, and phytic acid contents. Significant differences emerged for all the studied traits. The results of the correlation study indicated that grain Fe and Zn contents had a positive genetic link with each other while a non-significant negative association with phytic acid and grain yield. A substantial positive correlation of grain yield occurred with rows per cob, grains per row, and grains per cob. Cluster and principal component analyses ran through, with PA/Fe and PA/Zn molar ratios calculated to estimate the mineral bioavailability. Based on the genetic variability for grain yield, Fe, Zn, and PA contents, four clusters resulted, and the first two PCs had an eigenvalue of more than one and depicted 76.91% of the total variance. Genotypes M-11, M-41, M-45, M-56, M-60, M-61, M-66, M-80, M-96, and M-98 showed high Fe and Zn contents with low molar ratios and are potential to benefit further breeding programs to develop biofortified maize hybrids.

Evaluation of the Content of Micro- and Macroelements in Raspberries Depending on the Species, Cultivar Variety, and Geographical Environment.

The study aimed to analyse the macro- and micro-nutrient content in fruits of Rubus species (R. idaeus, R. occidentalis, R. chamaemorus, and R. chingii) and their varieties or hybrids from different regions. Flame atomic absorption spectrometry with deuterium background correction was used to measure concentrations of nine essential elements (K, Mg, Ca, Na, Mn, Fe, Cr, Zn, and Cu) and two heavy metals (Pb, Cd). Chemometric analysis compared the elemental profiles. Results confirmed raspberries as a rich source of macroelements (K, Mg) and microelements (Zn, Cu, Mn, Cr). The 'Bristol' cultivar consistently had the highest Fe content regardless of origin. Cr presence was observed in black raspberries for the first time. Previously observed relationships like K-Na antagonism and Cr/Zn, Fe/Zn synergism were found in raspberry fruits. Factor and cluster analyses demonstrated species and geographical diversity among Polish raspberry samples and clear separation of R. chingii from China. Raspberry fruits, due to the rich complex of polyphenols, are classified as superfoods, and the content of bioelements determined in them guarantees coverage of the daily requirement for macro- and microelements (RDA depending on the element: 5.6-204% for R. idaeus, 8.8-469, 4% for R. occidentalis, and 1.4-67.2% for R. chamaemorus), finally confirming this opinion.

Differences in Fe toxicity response index and associated growth characteristics among rice genotypes

ABSTRACT Acid sulfate soils in tropical coastal rice areas contain high Fe levels, and excess ferrous (Fe2+) ions are released during the early growth stage in the wet season. In such environments, Fe toxicity can cause significant yield losses. The objectives of this study were to evaluate the seedling growth of diverse rice germplasm (from japonica, aus and indica groups) under high-Fe conditions in hydroponic culture and to elucidate the growth characteristics of Fe toxicity tolerant genotypes. We calculated an Fe toxicity response index (FTRI) as a selection criterion that reflects both the response of shoot biomass to high Fe and the amount of Fe-induced leaf bronzing damage: higher FTRI values indicate greater tolerance to high Fe levels. We first compared Fe levels to determine the appropriate conditions for genotype selection, and then screened 2- to 3-week-old seedlings grown for 2 more weeks in hydroponic solution containing 500 mg Fe2+ L−1. Sixteen genotypes were screened, and for five of them, the differences in FTRI corresponded with previously reported yield performance in high-Fe fields. We identified Taichung65 (temperate japonica) as a promising donor, as it showed little bronzing damage and high relative (stress/control) biomass under high-Fe conditions, resulting in a high FTRI. Plant nutrient analyses of Taichung65 suggested that maintenance of low Fe concentration and low total Fe content in shoots despite high Fe concentration in the rhizosphere, through prevention of either root Fe uptake or Fe translocation from the root to the shoot, should be an important mechanism of Fe toxicity tolerance.

Effects of various factors on gangue removal in alkaline hydrothermal treatment of iron ores

The upgrading technology of low-grade iron ores by alkaline treatment was investigated in this study. The basic experiments (evaluation of the effects of solvent types, treatment temperature, holding time, solvent concentration, particle size, and solid–liquid ratio) were carried out with the alkaline hydrothermal treatment in a small batch-type reactor. The gangue removal rate in the 5 M NaOH hydrothermal treatment increased with the increase in treatment temperature, and about 90% of Si, Al, and P could be removed below 250 °C. The gangue removal rate tended to increase with the increase in NaOH concentration, the decrease in particle size, and the decrease in solid–liquid ratio. The order of the removal rate was P < Al < Si. The optimum conditions for alkaline hydrothermal treatment were found to be as follows: particle size, <500 μm; solvent, NaOH; solvent concentration, >0.1 M; solid–liquid ratio, ≤1.2; heating temperature, ≥150 °C; and holding time, 30 min. According to the results of XRD and N2 adsorption measurements of the treated ores, the gangue removal from low-grade iron ores, the improvement of Fe quality (higher Fe content), and densification were possible by alkaline hydrothermal treatment.

Contribution of natural and agricultural activities on Fe dynamics: Insights from Fe isotope in soils under different land-use types

Evaluating the contribution of natural and agricultural factors on Fe dynamics in soils is crucial to the study of material cycling in critical zone observation. Five soil profiles under cultivated land, abandoned cultivated land, grassland, shrub land, and secondary forest from Puding karst catchment in Guizhou Province, China, were analyzed to identify natural and agricultural contributions to Fe processes. Vertical distribution changes of Fe content and Fe isotopic compositions (δ56Fe) were investigated. The results presented that natural chemical weathering accompanied by soil erosion occurs primarily in the upper layer, leading to the loss of Fe from the surface to the bottom during the eluviation-illuviation process. Fe isotopic fractionation occurred in soils rich in natural organic matter (i.e., secondary forest and shrub land), resulting in the accumulation of lighter Fe isotopes. Soil impacted by anthropogenic activity have higher Fe content (e.g., cultivated land or abandoned cultivated land). The reduction of Fe is the principal cause of light Fe isotopes in the upper layer, which is caused by periodic artificial irrigation on cultivated land. Compared to worldwide soils, Puding soils are impacted by natural organic matter, eluviation-illuviation, and agricultural activities, which tend to modify Fe isotopic signatures on a local scale within soil profiles. Fe isotopic fractionations in bulk soils among different land-use soils are very limited. This study provides insightful analysis based on Fe isotopic to recognize natural and anthropogenic activities on Fe dynamic, and offers information on material cycling in the Puding karst catchment.

Exploring the linkage between root system architecture and grain iron content in wheat (Triticum aestivum L.)

Iron (Fe) is a vital element that is equally important for plants, animals, and humans. High Fe concentrations in wheat grains have reliance on plant roots, the hidden half of the plant with a role in nutrient mining. Enhanced grain Fe content of wheat can positively mitigate Fe malnutrition in poor populations. In the present study, 100 wheat varieties were studied to identify the root architectural characteristics in relation to grain Fe concentration. Germinated seeds were transplanted in a rhizobox kept in a standard nutrient solution and were harvested 12 days after transplanting. Roots were scanned and the images were processed using smart root software. A total of 12 wheat varieties, which had a vigorous and weak root system architecture (RSA), in combination with higher and lower Fe grain concentrations, were selected using principal component analysis. The uptake and translocation of Fe from root to shoot were determined through a pot experiment conducted for the above-mentioned 12 wheat varieties, with or without Fe fertilizer applied as FeSO4 to the soil. The data obtained from the pot experiment revealed that Dharabi-11 with vigorous RSA exhibited the highest grain Fe concentration (57.20 mg kg−1), low phytate concentration (6.50 mg kg−1), and maximum 1,000 grain weight, whereas Ujala-16 with weaker RSA had the lowest grain Fe concentration (13.33 mg kg−1), highest phytate concentration (9.07 mg kg−1), and lowest 1,000 grain weight. There were also varieties showing higher grain Fe concentrations with weaker RSA and vice versa. Although it is indicated that vigorous RSA leads to high grain Fe concentration, it is not the sole factor in high grain Fe concentration. Nevertheless, the results demonstrate that large genetic diversity is available among indigenous wheat germplasm in terms of grain Fe concentration and RSA. This information may be utilized in the development of new varieties through conventional and marker-assisted breeding programs using RSA traits for Fe biofortification in wheat, leading to the mitigation of Fe malnutrition.

Optimizing calcination of coal by-products for maximizing REE leaching recovery and minimizing Al, Ca, and Fe contamination

High-temperature calcination is effective in improving the leaching characteristics of rare earth elements (REEs) from conventional REE-bearing minerals by transforming them into more leachable forms. However, the recovery of contaminants such as Al, Fe, and Ca also increases significantly. The objective of the study was to maximize the REE extraction while minimizing the concentration of contaminant ions (Al, Ca, and Fe) in the leach solution. Representative density fractions of the coarse refuse from the Baker and Fire Clay seam coal refuse were pulverized to a top size of 180 μm and used as a feedstock for the study. All the samples generated from thermal treatment were leached at 1% (w/v) using 1.2 mol/L sulfuric acid at 75 °C for 2 h. Test results from a parametric program based on a Box-Behnken design were used for modeling and optimization of three operating parameters associated with the lab-scale calcination process. The parameters included temperature (400–800 °C), ramp rate (2–10 °C/min) and holding time (0–120 min). It was determined that the calcination temperature was the most significant parameter influencing REE recovery. The majority of the heavy rare earth elements (HREEs) were found to be present in an insoluble form in the calcination products and were marginally affected by thermal treatment. A strong correlation between light rare earth elements recovery (LREEs) and Al suggested a possible association with clays. The optimum operating conditions for high REE recovery with comparatively lower contaminant concentration for 1.6 specific gravity float and 2.2 sink fractions of Baker and Fire Clay seam material were determined to be at 776, 800 °C and 407, 800 °C, calcining temperatures, respectively. A higher optimum temperature of 1.6 float fraction of Baker seam relative to Fire Clay seam material was due to elevated pyrite concentration in Baker seam material. Thermal treatment at 400 °C converted pyrite into a soluble intermedium iron oxide, resulting in a high Fe content in the leachate. Calcining at 776 °C converted most of the soluble iron oxide into insoluble α-hematite, considerably reducing the Fe concentration in the solution.

Sewage phosphorus recovery through sachets loaded with water treatment plant sludge.

Conventional wastewater treatment plants (WWTPs) present low phosphorus (P) removal capacity. Conversely, water treatment plants (WTPs) produce sludge with great P sorption from wastewater; however, directly adding the sludge into the wastewater treatment system could increase the effluent turbidity. As a novel approach, the present study evaluated the performance of WTP sludge within paper sachets for P removal from treated sewage. Different sludge concentrations (2-30 g L-1) and contact times (1-27 d) were applied to treat sewage from a university WWTP outlet. The sludge was characterized by P, Fe, and Al content. Larger sludge masses showed higher P removal efficiencies due to their high Fe content, especially at longer contact times (up to 100% at the final of the experiment). However, there is a more significant P reduction in the first 10 d (more than 90% in the most efficient treatment - 30 mg L-1). Based on the kinetic and isotherm analyses and the sludge chemical composition, precipitation proved to be a mechanism of great importance in P removal. Therefore, WTP sludge sachets can be a promising way to remove P from sewage, and the formed solid waste might be reused as an alternative fertilizer.

Equilibrium magnetic properties of the Fe-doped HTSC YBaCuO

For the polycrystalline high-temperature superconductor Y1 –xFexBa2Cu3Oy (0 ≤ x ≤ 0.05), where a significant increase in the intragrain critical current density has recently been found, the effect of iron doping on the equilibrium magnetic characteristics is studied. The field dependences of the magnetization are measured in the temperature range of 40–85 K and in the field range up to 60 kOe with increasing and decreasing fields. The temperature dependences of the London penetration depth λab, the superconducting carrier density ns, and the thermodynamic critical field Hc are determined from an analysis of the middle lines of the magnetic hysteresis loop. It is shown that the thermodynamic properties of Fe substituted samples do not change at x ≤ 0.03. At a higher Fe content, a slight decrease in Hc and the superconducting transition temperature is observed. However, changes in the condensation energy turn out to be much smaller than values expected due to an increase in the density of effective pinning centres created by substitutional atoms in both the yttrium and copper sublattices. It is concluded that the pinning regions in chain CuO planes near substituted Cu sites are two-dimensional in nature and do not affect the superconducting pairing in CuO2 planes. Another possible pinning mechanism, which does not affect Hc, is the interaction of vortices with the magnetic moments of Fe3+ ions.