Average Fe Content Research Articles

An evaluation of the analytical and biological robustness of a method for quantifying iron in individual red blood cells via single-cell tandem ICP-mass spectrometry

This work evaluated the analytical and biological robustness of iron (Fe) determination in individual red blood cells (RBCs) via single-cell ICP-MS (SC-ICP-MS). RBCs were separated from other whole blood constituents using Ficoll-Paque™ density gradient centrifugation. While fixation with paraformaldehyde (PFA) led to RBC lysis, the use of glutaraldehyde (GA) left the RBCs intact and permitted storage of RBC cell suspensions in ultra-pure water for up to 16 months at 4 °C. GA-fixation also rendered the RBCs sufficiently robust to maintain integrity during their introduction into the ICP by means of nebulization of dilute suspensions. Obtaining quantitative data on a cell-per-cell basis required determination of the transport efficiency using the particle size method and external calibration against aqueous Fe standard solutions. The average Fe content per RBC obtained using SC-ICP-MS (average value of 103 fg/cell) agreed well with the value obtained using solution-based ICP-MS obtained after cell pellet digestion and with values obtained from literature. Variation of the cell number density in the suspensions analyzed between 1.5 × 105 and 6.0 × 105 cells per mL did not affect the result. Identical results from one-week interval blood drawings from healthy individuals demonstrate biological consistency. Compared to bulk analysis, the SC-ICP-MS approach offers the added value of providing information on the cell-to-cell heterogeneity in Fe content.

Quantitative analysis of soil quality around brick kilns using pollution indices and ANOVA in Jammu district of Jammu and Kashmir, India

The study investigated soil quality around brick kilns in the Jammu district of Jammu and Kashmir, analyzing 200 samples from 50 sites for selected parameters such as pH, electrical conductiv1ity, soil temperature, organic carbon content, organic matter, macronutrients, and heavy metals. The findings revealed that soil electrical conductivity ranged from 0.33 to 0.63 dS/m, with significant differences observed at varying distances from the kilns. Copper concentrations were highest at 5.32 mg/kg near the kilns, while iron and lead levels also varied significantly, indicating potential contamination. The mean soil temperature was recorded to be 27.69°C.The pH values ranged from 6.5 to 7.8, and the average pH of 8.22 indicated the slightly alkaline nature of the soil around the brick kilns. The organic carbon ranged from 0.34% to 1.02%.Soil temperature and electrical conductivity decreased with increasing distance from the kilns, with temperature showing positive correlations with organic carbon, organic matter, nitrogen, potassium, manganese, and iron and negative correlations with pH, phosphorus, zinc, copper, lead, and cadmium. A perfect positive correlation was noted among nitrogen, organic carbon, and organic matter. Heavy metals, except for zinc and manganese, showed positive correlations with each other. The average Zn, Cu, Mn, Fe, Pb and Cd concentration was recorded as 1.07, 1.03, 6.71, 10.30, 37.04 and 1.91 ppm, respectively. The contamination factor indicated moderate contamination with lead and cadmium, while the geo-accumulation index also suggested moderate contamination. The pollution load index reflected unpolluted soil and enrichment factor values for heavy metals ranked as Cd > Pb > Cu > Zn > Mn > Fe.ANOVA results revealed significant variations in electrical conductivity, copper, iron, and lead, underscoring the potential environmental impacts at different distances from the kilns. However, no significant differences were found between agricultural and non-agricultural sites in other physicochemical parameters. These variations highlight the considerable impact of brick kilns on soil health, emphasizing the need for enhanced environmental management and further research to mitigate these effects.

Analysis of Iron (Fe) Content in Breast Milk of Breastfeeding Mothers with Level Anemia Normal, Mild and Moderate

Aims: The study aimed to determine the level of iron (Fe) in breast milk samples from breastfeeding mothers who were not anemic (normal), had mild anemia, and had moderate anemia. Methodology: This research is descriptive in nature with a cross-sectional research design. The research subjects were 30 breast milk samples from breastfeeding mothers who had babies aged 0-6 months in TTU Regency, East Nusa Tenggara. 10 samples each in the categories of no anemia (normal), mild anemia, and moderate anemia. Analysis of Fe levels in breast milk samples using Atomic Absorption Spectroscopy (SSA) at the Testing, Calibration, and Certification Services Laboratory Unit, Bogor Agricultural Institute. Results: The results of the analysis showed that the average Fe content in breast milk samples from breastfeeding mothers (normal category) was 4.17 mg/L; Fe levels in breast milk samples from breastfeeding mothers (mild anemia category) were 2.01 mg/L; while the Fe level in breast milk samples from breastfeeding mothers (moderate anemia category) was 1.05 mg/L. From the average figures, it can be seen that there is no significant difference in Fe levels between the three breast milk samples, which is confirmed by the distribution of Fe levels for the 30 samples which is not much different, even from the minimum number of Fe levels in breast milk samples from breastfeeding mothers (normal). still found at 1.03 mg/L (almost the same as the minimum Fe level for breast milk samples from breastfeeding mothers (mild anemia), namely 0.70 mg/L. Conclusion: there were no significant differences in Fe levels in breast milk samples from breastfeeding mothers in the categories of no anemia (normal), mild anemia, and moderate anemia. However, it is still recommended that it is very important to ensure sufficient iron in breast milk to help the baby's growth and development.

Impact of air quality on the health of present-day workers in an Asbestos roof manufacturing industry, Sri Lanka.

The study's objective was to determine the air quality in an asbestos-related industry and its impact on current workers' respiratory health. Seventy-seven air and 65 dust samples were collected at 5-day intervals in an asbestos roofing sheets production factory in Sri Lanka having two production facilities. Sampling was performed in ten sites: Defective sheets-storage, Production-plant, Pulverizer, Cement-silo, and Loading-area. A detailed questionnaire and medical screening were conducted on 264 workers, including Lung Function Tests (LFT) and chest X-rays. Asbestos fibres were observed in deposited dust samples collected from seven sites. Free chrysotile fibres were absent in the breathing air samples. Scanning Electron Microscopy confirmed the presence of asbestos fibres, and the Energy Dispersive X-ray analysis revealed Mg, O, and Si in depositions. The average concentrations of trace metals were Cd-2.74, Pb-17.18, Ni-46.68, Cr-81.01, As-7.12, Co-6.77, and Cu-43.04mg/kg. The average Zn, Al, Mg, and Fe concentrations were within 0.2-163g/kg. The highest concentrations of PM2.52.5 and PM1010, 258 and 387µg/m3, respectively, were observed in the Pulverizer site. Forty-four workers had respiratory symptoms, 64 presented LFT abnormalities, 5 indicated chest irregularities, 35.98% were smokers, and 37.5% of workers with abnormal LFT results were smokers. The correlation coefficients between LFT results and work duration with respiratory symptoms and work duration and chest X-ray results were 0.022 and 0.011, respectively. In conclusion, most pulmonary disorders observed cannot directly correlate to Asbestos exposure due to negligible fibres in breathing air, but fibres in the depositions and dust can influence the pulmonary health of the employees.

Metal leakage from orthodontic appliances chemically alters enamel surface during experimental in vitro simulated treatment

Human enamel is composed mainly of apatite. This mineral of sorption properties is susceptible to chemical changes, which in turn affect its resistance to dissolution. This study aimed to investigate whether metal leakage from orthodontic appliances chemically alters the enamel surface during an in vitro simulated orthodontic treatment. Totally 107 human enamel samples were subjected to the simulation involving metal appliances and cyclic pH fluctuations over a period of 12 months in four complimentary experiments. The average concentrations and distribution of Fe, Cr, Ni, Ti and Cu within the enamel before and after the experiments were examined using ICP‒MS and LA‒ICP‒MS techniques. The samples exposed to the interaction with metal appliances exhibited a significant increase in average Fe, Cr and Ni (Kruskal–Wallis, p < 0.002) content in comparison to the control group. The outer layer, narrow fissures and points of contact with the metal components showed increased concentrations of Fe, Ti, Ni and Cr after simulated treatment, conversely to the enamel sealed with an adhesive system. It has been concluded that metal leakage from orthodontic appliances chemically alters enamel surface and microlesions during experimental in vitro simulated treatment.

Estimation of iron, zinc, phytic acid concentration and protein content in lentil seeds over locations and their marker-trait association analysis

In the present study, a diverse set of 96 lentil accessions including biofortified variety IPL 220 was used to identify sources of high concentration for Fe and Zn along with low phytic acid concentration and high protein content. Further, Marker Trait Association (MTA) analysis was performed to find molecular markers controlling these nutritional traits. The average Fe, Zn and phytic acid concentration and protein content ranged from 46.5 to 94.8 (mg/kg), 21.5 to 45.3 (mg/kg), 3.7 to 9.3 (mg/kg) and 18.1–28.7 (%), respectively over the locations. This study showed variability for these traits as coefficient of variation was 11.1% for Fe, 18% for Zn, 18.3% for phytic acid and 8.71% for protein content over two locations. The standard error (S.E.) of mean ranged from 0.05 to 21.5 for Fe, 0.15 to 9.71 for Zn, 0.05 to 2.10 for phytic acid and 0.06 to 6.16 for protein content further calculated across the locations. MTA analysis following general linear model resulted in the identification of 31 MTAs for three traits at p < 0.05 explaining 10 to 26% of total phenotypic variation. Association of PBA LC0203 marker with Fe concentration explained the highest proportion of total phenotypic variation (26%) at Kanpur location. However, same marker with different loci also showed association with Fe concentration at Bhopal location explaining 11% of total phenotypic variation. This study also identified association of some genetic markers with more than two nutritional traits that provides opportunity of improving more than two positively associated nutritional traits through marker assisted selection simultaneously. In the present study, EST-SSR markers were used as functional markers for developing high yielding bio-fortified lentils.

Container substrate components are a potential source of micronutrients for plant growth

The objective was to quantify the extractable micronutrient levels from container substrate components and limestone and their potential contribution as fertilizer sources for crop growth. Samples of horticultural limestone (29 samples) and substrate components [peat (48 samples), perlite (10), vermiculite (14), bark (15), and coconut coir (6)] were analyzed for micronutrient content with the SME (Saturated Medium Extract) method using either water (SMEW) or diethylenetriamine pentaacetate (SMED) as extractants for the substrate components, or following acid digestion of limestone samples. Samples were obtained from commercial substrate and greenhouse companies throughout the U.S. and Canada. Peat included 36 peat samples from two peat bogs in Alberta Canada to evaluate whether species composition, decomposition, and bog location affected micronutrient content. Increasing von Post decomposition increased SMEW and SMED Mn level and SMED Zn. As percent Sphagnum fuscum increased, extractable Fe and Mn levels increased for both extractant types, and SMEW extractable Zn increased. Based on established SME guidelines for acceptable to optimum nutrient levels for soilless substrates, peat and bark could potentially provide sufficient Fe and Mn to contribute to plant requirements. Average Fe content in limestone was 0.11%, and Mn content was 0.012%. Based on SMED extractions and lime analysis, Fe supplied by 100% peat and lime could potentially provide Fe at levels comparable with commercial pre-plant fertilizers if these Fe sources are plant-available. Substrate-pH affected solubility of Fe, Mn and Zn in peat. As substrate-pH increased, Fe and Zn solubility in peat decreased with both SMEW and SMED. The SMEW-extractable Mn decreased with increasing pH, in contrast to SMED-extractable Mn which increased as pH increased. Analysis of raw materials using SMED (substrate components) or complete digestion (limestone) is advised for substrate companies to proactively identify batches of components that may affect crop nutrition. Given this high level of potential contribution of Fe by peat and lime, it is likely that these uncontrolled sources contribute to nutrient uptake in horticultural production. However, further research is required to compare extractable micronutrients with actual plant uptake.

Characterization of iron meteorites by scanning electron microscopy, X‐ray diffraction, magnetization measurements, and Mössbauer spectroscopy: Gibeon IVA

AbstractGibeon IVA iron meteorite fragment was characterized using optical microscopy, scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), X‐ray diffraction (XRD), magnetization measurements, and Mössbauer spectroscopy. Optical microscopy and SEM made on the polished section of the meteorite, show the presence of α‐Fe(Ni, Co) and γ‐Fe(Ni, Co) phases and plessite structures. There are no troilite inclusions observed in the studied section. EDS studies indicate some variations in the Ni concentrations: (i) within the α‐Fe(Ni, Co) phase in the range ~5.0 ± 0.1 – ~7.5 ± 0.1 at% and (ii) within the γ‐Fe(Ni, Co) phase in the range ~26.0 ± 0.2 – ~36.1 ± 0.2 at%. The latter Ni concentration range indicates the presence of small amount of the paramagnetic γ‐phase in addition to the ferromagnetic γ‐phase. EDS also shows that Ni content in two plessite structures is varying in the range ~16–37 at%, which can indicate the presence of only the α2‐Fe(Ni, Co) and γ‐Fe(Ni, Co) phases in the duplex plessite structure. This may be a result of the γ‐phase decomposition with the incomplete martensitic transformation: γ → α2 + γ due to a faster cooling rate. XRD indicates the presence of ~1.3 wt% of the γ‐Fe(Ni, Co) phase in Gibeon VIA. The saturation magnetization moment of 185(2) emu g−1 obtained also confirms the presence of phases with low and high Ni concentrations. The most appropriate fit of the Gibeon IVA Mössbauer spectrum demonstrates the presence of five magnetic sextets and one paramagnetic singlet which are assigned to the ferromagnetic α2‐Fe(Ni, Co), α‐Fe(Ni, Co), γ‐Fe(Ni, Co), and paramagnetic γ‐Fe(Ni, Co) phases. The relative average Fe contents in these phases are: 13.4% in the α2‐Fe(Ni, Co) phase, 78.3% in the α‐Fe(Ni, Co) phase, and 8.3% in the ferromagnetic and paramagnetic γ‐Fe(Ni, Co) phases.

Applying Chemical and Statistical Analysis Methods to Evaluate Water and Stream Sediments around the Coal Mine Area in Dazhu, China

In this study, groundwater, stream water, and stream sediment samples were collected from a coal mine area in Dazhu, Southwestern China, and hydrogeochemical, multivariate, and X-ray analyses were conducted to examine the effects of coal mine pollution. The groundwater and stream samples were slightly acidic to alkaline (6.7 to 8.2). Typically, the water samples were dominated by Ca2+ + Mg2+–HCO3− and Ca2+ + Mg2+–Cl−. SO42− originates from gypsum dissolution and pyrite oxidation, and Ca2+ and Mg2+ may be related to the dissolution of carbonate. According to the Chinese standard and World Health Organization guidelines, the water in the coal mine area is of good quality in terms of its physical and chemical properties, except for the concentration of Mn and Fe, with values of 1925.14 μg/L and 12,872.88 μg/L, respectively. A principal component analysis revealed two groups in which the concentration of metals and metalloids in stream sediments are affected by the coal mine drainage. The Mn and Fe average concentration in the downstream Kongjiagou drain sediment samples was 2035.1 ppm and 6%, respectively. These values were higher than the average Mn and Fe concentration in Xiaojiagou at 453.1 ppm and 2.9%, respectively. Both the Mn and Fe concentration were higher than the background values (640 ppm and 4.4%).

Total organic carbon, aluminium and iron in bulk samples and aggregate size fractions of a sandy clay loam humic soil under sugarcane relative to native forest in northern KwaZulu-Natal, South Africa

The distribution of total aluminium (Al) and iron (Fe) and organic carbon (TOC) in aggregate fractions gives an insight into the dynamics of these elements in soil. This study determined the effects of over 30 years of sugarcane cultivation, compared to adjacent native forest, on Al, Fe and TOC in bulk soil and aggregate fractions within the 100 cm depth of a sandy clay loam humic soil. Samples were separated into large macro-aggregates: LM (>2000 μm), small macro-aggregates: SM (250–2000 μm), micro-aggregates: M (250-63 μm) and silt + clay: SC (<63 μm) fractions. The TOC was analyzed by dry combustion and total Al and Fe by X-ray fluorescence spectrometry. Sugarcane cultivation (i) reduced macro-aggregates and TOC and (ii) increased the SC fraction and total Al and Fe. The mean weight diameter declined from 1.32 mm (0–30 cm) to 1.06 mm (30–100 cm) under forest. Average (0–100 cm) Al and Fe contents (g kg−1) increased in LM (6–16 for Al; 6 to 9 for Fe), SM (7–11 for Al), M (5–14 for Al; 6 to 9 for Fe) and SC (7–16 for Al; 9 to 10 for Fe) under sugarcane relative to forest. The TOC (g kg−1) declined in the LM (13–7) and SM (7–6) but increased in the M (5–9) and SC (10–13) due to cultivation. These findings suggested that sugarcane cultivation decreases aggregate stability and TOC in macro-aggregates, and increases Al and Fe in all aggregates. Adoption of practices inclined to improve or maintain TOC as well as liming to increase pH are necessary management practices for sustainable production.

Contribution of School Canteen's Snacks to The Iron Fulfillment in Malang High Schools

Inadequate dietary iron, impaired iron absorption, bleeding, or loss of body iron in the urine may cause anemia. The prevalence of anemia due to iron (Fe) deficiency in Indonesia reaches 22.7% in females and 12.4% in males. Indonesian students spent 7-8 hours/day, mainly the iron daily intake influenced by school canteen snacks. This study aimed to determine the contribution of Fe content in canteen snacks in high schools in Malang. This research was an analytic observational study using a cross-sectional design with the AAS (Atomic Absorption Spectrometry) method as a quantitative iron analysis technique. Food samples were selected purposively according to the inclusion criteria from 10 high schools consisting of junior high and senior high school groups. The snack samples studied were fried chicken, fried Tempe, and noodles. The average Fe content in snacks was analyzed using the independent T-test in the junior and senior high school groups. The iron content in fried Tempe and noodle showed a significant difference with p&gt; 0.05, while the iron content in fried chicken in the two school groups did not show different results. However, the percentage contribution of Fe to the Nutrition Adequacy Rate (RDA) is still minimal, with the most significant contribution coming from noodles, reaching 17.85% in the male group.

Profile distribution of trace elements under different land-use systems in North East India

ABSTRACT An investigation was carried out to study the depth-distribution of available trace elements and their relationship with soil physico-chemical properties in soils of Golaghat district, India. Soil samples were collected at 0-20 cm, 20-40 cm, 40-60 cm, 60-80 cm and 80-100 cm depth under five land use systems (LUS) viz. rice, vegetable, sugarcane, bamboo and tea. Particle size distribution data showed significant variation among the diverse LUS and soil depths. Soils were very strongly to medium acidic with a pH range of 4.7 to 5.7 and the highest was recorded at 80–100 cm depth under all the LUS. Soil organic carbon (SOC) content was higher in the surface layer and decreased with increasing soil depths. The highest (13.3 g kg−1) and lowest content of SOC (1.5 g kg−1) in soil were observed under tea and bamboo LUS. Exchangeable cations, cation exchange capacity and base saturation were higher in soils under rice LUS as compared to other LUS. Average DTPA extractable Fe, Mn, Zn and Cu content of the soils ranged from 10.3 to 80.3, 2.0 to 29.2, 0.1 to 0.8 and 0.1 to 1.8 mg kg−1 under diverse LUS.

Titaniferous-Vanadiferous, Magnetite-Ilmenite Mineralization in a Mafic Suite within the Chhotanagpur Gneissic Complex, Bihar, India

Titanium or vanadium metals or their alloys are important industrial metals/alloys. Because these resources are in short supply, the investigation of potential titaniferous-vanadiferous deposits needs special attention to bridge the supply-demand gap. The study integrates geological, geochemical, remote sensing, and geophysical data for assessing the potentiality of titaniferous-vanadiferous, magnetite-ilmenite mineralization in and around the Sudamakund and Paharpur areas, Gaya and Jehanabad districts, Bihar, India, and delineation of specific targets for detailed exploration. Field visits for large scale mapping on (1:12,500 scale) were used to conduct a reconnaissance survey for magnetite-ilmenite mineralization in parts of toposheet number 72G/04 in the Gaya and Jehanabad districts of Bihar, as well as the collection of bedrock samples (BRS), pit/trench samples (PTS), petrographic samples (PS), and petrochemical samples (PCS), followed by petrographic and ore microscopic study, and interpretation of chemical results. Signatures of oxidized iron-bearing sulphides (iron-oxides ratio) and other ferrous-iron-bearing minerals surrounded by altered rocks (clay bearing minerals) are visible in remote sensing images. The geological work was followed by ground geophysical gravity and magnetic surveys in selected blocks by the Geophysics Division, eastern region (ER) on a 1:12,500 scale. The magnetite ore is hard, compact, crystalline, and at some places, granular in nature. The analytical value of these magnetite ore bodies indicates average Fe content at 49.53% (range 25.85–60.78%), with a considerable amount of TiO2 (average 15.85%, range 1.47–26.77%), and V (average 144.79 ppm, range 30.00–256.00 ppm, from PTS). The trends of these magnetite ore deposits correspond to the major lineaments (NE-SW and NW-SE). The superimposition of gravity and magnetic contour maps with the geological map (1:12,500 scale) helps explain the observed geophysical anomalies, and the possible subsurface (horizontal and vertical) expansion of magnetite ore deposits in alluvium cover regions warrants further investigation.

Assessment of Heavy Metal Pollution in the Surface Water of the Doi Canal, the Cho Dem and Ben Luc Rivers, Vietnam

The Doi Canal and the Cho Dem and Ben Luc Rivers play the key roles in irrigation, navigation and ecological restoration. It is important to clearly identify the pollution, influencing factors, ecological risks and possible sources of heavy metals in the surface water of this river system. The surface water of 7 sampling sites was collected over 7 consecutive periods from April 2019 to October 2021. Each surface water sample was analyzed for 9 heavy metals including Fe, Mn, Cr, Zn, Cu, Pb, Cd, Ni, As. Sampling and sample handling techniques were performed based on the Standard Methods for the Examination of Water and Wastewater. Among all nine heavy metals examined in the study area, the concentrations of Fe (1.00 ¸ 5.06 mg/L) and Mn (0.14 ¸ 0.28 mg/L) were the highest and the concentrations of Cr, Cd and As were below the lower limit of detection. The results showed that the average Fe and Mn contents both exceeded the permissible thresholds of the National technical regulation on surface water quality (QCVN 08-MT: 2015/BTNMT). Additionally, the content of Fe, Mn, Zn, Cu, Pb, Ni did not meet the water quality standards for aquatic life (United State Environmental Protection Agency). Keywords: Distribution; Heavy metal pollution; River; Surface water; Water quality protection.

Grain zinc and iron concentrations of Chinese wheat landraces and cultivars and their responses to foliar micronutrient applications

Grain zinc (Zn) and iron (Fe) concentrations and their responses to foliar application of micronutrients in 28 Chinese wheat landraces and 63 cultivars were investigated in a two-year field experiment. The average grain Zn and Fe concentrations were 41.8 mg kg−1 (29.0−63.3 mg kg−1) and 39.7 mg kg−1 (27.9−67.0 mg kg−1), respectively. Compared with cultivars, landraces had greater grain Zn (11.0%) and Fe (4.8%) concentrations but lower harvest index (HI), grain weight per spike (GWS), grain number per spike (GNS) and thousand grain weight (TGW). Both Zn and Fe concentrations were negatively and significantly correlated with HI, GWS, and GNS, while showed a poor association with TGW, suggesting that lower HI, GWS, and GNS, but not TGW, accounted for higher Zn and Fe concentrations for landraces than for cultivars. Grain Zn concentrations of both cultivars and landraces significantly increased after foliar Zn spray and the increase was two-fold greater for landraces (12.6 mg kg−1) than for cultivars (6.4 mg kg−1). Foliar Fe spray increased grain Fe concentrations of landraces (3.4 mg kg−1) and cultivars (1.2 mg kg−1), but these increases were not statistically significant. This study showed that Chinese wheat landraces had higher grain Zn and Fe concentrations than cultivars, and greater increases occurred in grain Zn concentration than in grain Fe concentration in response to fertilization, suggesting that Chinese wheat landraces could serve as a potential genetic source for enhancing grain mineral levels in modern wheat cultivars.

Iron Exports From Catchments Are Constrained by Redox Status and Topography

AbstractFe(III) hydroxides stabilize organic carbon (OC) and P in soils. Observations of rising stream Fe concentrations are controversially posited to result from a flushing of iron‐rich deeper soil layers or a decrease of competing electron acceptors inhibiting Fe reduction ( and ). Here, we argue that catchment topography constrains the release of Fe, OC, and P to streams. We therefore incubated organic topsoil and mineral subsoil and modified the availability of . We found that Fe leaching was highest in topsoil. Fe, OC, and P released at quantities proportional to their ratios in the source soil. Supply of reduced Fe leaching to 18% and increased pore water OC:Fe and P:Fe ratios. Subsoil, however, was an insignificant Fe source (&lt;0.5%). Here, the leached quantities of Fe, OC and P were highly disproportionate to the soil source with an excess of released OC and P. We tested if experimental findings scale up using data from 88 German catchments representing gradients in concentration and topography. Average stream Fe concentrations increased with decreasing and were high in catchments with shallow topography where high groundwater levels support reductive processes and topsoils are hydrologically connected to streams; but Fe concentrations were low in catchments with steep topography where flow occurs primarily through subsoils. OC:Fe and P:Fe ratios in the streams similarly varied by and topography. This corroborates the findings from the laboratory experiment and suggests that catchment topography and competing electron acceptors constrain the formation of Fe‐reducing conditions and control the release of Fe, OC, and P to streams.

Treatment and recovery of iron from acid mine drainage: a pilot-scale study

The acid mine drainage (AMD) formed during copper mining and smelting has a low pH, high sulfate concentration, and large amounts of valuable metals such as Fe, Cu, and Mn. In order to achieve step-by-step recovery of these resources, it is necessary to first remove high concentrations of iron from the wastewater. In this study, chemical oxidation technology was applied to establish a 12 m3/d pilot-scale treatment process to precipitate high-concentration iron (510.3 ± 50 mg/L) under acidic conditions. The experimental results showed that the Fe2+ oxidation rate and TFe (total Fe) removal rate exceeded 99%, while the loss of Cu and Mn did not exceed 4%. The average Fe content of the recovered sludge was 26.85%, which signifies good recycling value. In addition, an economic analysis showed that this method was 14 cents cheaper per m3 than the traditional lime neutralization method for treating AMD, which would result in large annual savings for sludge treatment costs.

Redefining Bean Iron Biofortification: A Review of the Evidence for Moving to a High Fe Bioavailability Approach

Iron biofortification of the common bean (Phaseolus vulgaris) commenced in earnest ~18 years ago. Based on knowledge at the time, the biofortification approach for beans was simply to breed for increased Fe concentration based on 3 major assumptions: (1) The average bean Fe concentration is ~50 μg/g; (2) Higher Fe concentration results in more bioavailable Fe delivered for absorption; (3) Breeding for high Fe concentration is a trait that can be achieved through traditional breeding and is sustainable once a high Fe bean sample is released to farmers. Current research indicates that the assumptions of the high Fe breeding approach are not met in countries of East Africa, a major focus area of bean Fe biofortification. Thus, there is a need to redefine bean Fe biofortification. For assumption 1, recent research indicates that the average bean Fe concentration in East Africa is 71 μg/g, thus about 20 μg/g higher than the assumed value. For assumption 2, recent studies demonstrate that for beans higher Fe concentration does not always equate to more Fe absorption. Finally, for assumption 3, studies show a strong environment and genotype by environment effect on Fe concentration, thus making it difficult to develop and sustain high Fe concentrations. This paper provides an examination of the available evidence related to the above assumptions, and offers an alternative approach utilizing tools that focus on Fe bioavailability to redefine Fe biofortification of the common bean.

Early Neoproterozoic oxygenation dynamics along the northern margin of the West African Craton, Anti-Atlas Mountains, Morocco

Emerging evidence suggests widespread ferruginous marine conditions promoted global seawater phosphate depletion and the maintenance of a low oxygen world at the start of the Neoproterozoic Era. However, the large-scale deposition of marine sedimentary Fe formations, as observed in the Paleoproterozoic, is rare in the early Neoproterozoic Era. We show that at the start of the Neoproterozoic, tidal flat and shallow marine environments along the northern passive margin of the West African Craton (WAC) were fully oxygenated and low in reactive Fe content, until an abrupt and prolong episode of deep-sea hydrothermal activity overwhelmed the WAC margin with strongly reducing Fe-rich hydrothermal fluids. This unique incident is recorded in meter-thick and kilometer-wide shallow marine siliciclastic platform rocks estimated to be ~883 Ma old and containing average bulk Fe content >22 wt% in the Wanimzi Formation in the Moroccan Anti-Atlas Mountains. The abrupt and conformable contact of the Fe-rich succession with the Fe-poor lower and upper transition boundaries, together with geochemical data, suggest rapid initiation and termination of seawater fertilization by the hydrothermal fluids that formed the unmetamorphosed hematite-rich ironstones. Rare Earth Element (REE) and Fe-based redox reconstruction point to an aftermath coincident with a return to shallow siliciclastic marine habitats characterized by a low reactive Fe content and negligible hydrothermal intrusion, where aerobic microbial communities flourished in well‑oxygenated waters. We propose that the early Neoproterozoic tectonic initiation of the breakup of the supercontinent Rodinia supplied large volumes of deep sea hydrothermal Fe, trace metals, and toxic metalloids like arsenic to shallow marine habitats along the WAC, resulting in rapid seawater deoxygenation.

Anthropogenic arsenic menace in contaminated water near thermal power plants and coal mining areas of India.

Coal mining and coal combustion in thermal power plants (TPPs) are the major anthropogenic sources of arsenic (As) contamination in many different industrial regions. In this study of industrial regions of West Bengal and Singrauli, it is observed that there is an anthropogenic contribution to the contamination from As-bearing coal. Up to 14.53mg/kg of As is obtained in coal of West Bengal which also has very high average Fe concentration (16,095mg/kg) along with high concentration of Cu, Mn and Hg. Similar observations are also found in Singrauli Industrial Region where 3.14mg/kg of As with very high concentration of Fe 43,867mg/kg along with high Cu, Mn and Hg concentration is found in coal samples. This low-grade bituminous coal contains arsenopyrite as observed by SEM-EDX. Arsenopyrite is converted to arsenolite upon combustion in these TPPs as observed in XRD. The fly ash has average As concentration of 1.53mg/kg for West Bengal and 2.38mg/kg for Singrauli Industrial Region and high concentration of toxic elements. The soil near these TPPs and mining areas is enriched in As, Fe, Hg, Cu and Mn. Not only As but high concentrations of Fe, Hg, Mn are also observed from analysis of water which relates to the anthropogenic inputs. The dissolution of arsenolite in reducing environments caused by periodic flooding releases As into water. Hence, the As contamination in the study area also has anthropogenic origin from coal consumption in TPPs.