High Fe Content Research Articles

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.

Ultra-fine microstructure and exceptional low coercivity developed in a high-Bs Fe-Si-B-P alloy by co-alloying Ni, Mo, and Cu

Designing soft magnetic alloys with high saturation magnetic induction (Bs) is of great importance for improving the power density of electric and electronic devices. For high-Bs nanocrystalline alloys, the main problem is the grain coarsening effect induced by high Fe content (>80 at.%), which deteriorates the soft magnetic properties. In present work, we designed new Fe-based nanocrystalline alloys by microalloying a Fe-Si-B-P alloy. The co-alloying of Ni, Mo, and Cu effectively refines the microstructure of nanocrystalline alloys from 28.5 nm to 13.1 nm and increased the stability of soft magnetic properties. Even though there are 28-nm-large surface crystallites in the amorphous precursors, an exceptional low coercivity of 1–2 A/m with a high Bs of 1.81 T was developed after nanocrystallization. These excellent magnetic properties could be maintained within a wide annealing temperature window of 50 K and an annealing time window up to 600 s for high heating rate annealing.

Exploring the Hidden Potential of Traditional Rice Landraces and Mutants for Iron and Zinc Concentration in Brown Rice to Develop Bio-fortified Rice Varieties

In the present study, 58 rice genotypes were evaluated for three consecutive seasons to enucleate the elite lines with high Fe and Zn contents. ANOVA revealed significant differences among the genotypes for Fe and Zn contents during all three seasons. Furthermore, PCV and GCV were moderate to high for Fe and Zn content during all three seasons. Similarly, high level of heritability and genetic advance were also recorded for both the traits. Iron content of Safri mutant 17-2-48 was consistently high for all the seasons whereas zinc content of Loktimachi was high for two seasons. Interestingly, rice genotypes Chhindmauri, Badsahbhog, Rudra, Danighoda and Suapankhi have been identified to have moderate to high Fe and Zn contents which could be used as donors for developing bio-fortified rice varieties. Stability analysis revealed that the genotypes Jhimiprass, Loktimachi, and CG Zinc Rice 2 for iron content and Rela Dhan, Chhindmauri, and CG Zinc Rice-1 for zinc content have had an average response to environment, making them appropriate for all seasons

High-strength Al–5Mg2Si–2Mg–2Fe alloy with extremely high Fe content for green industrial application through additive manufacturing

ABSTRACT Achieving superior mechanical properties of Al alloys with high content of Fe impurities is very challenging. Here, a feasible method was applied to accommodate high Fe content (∼2.2 wt.%) and obtain superior strength in an Al–5Mg2Si–2Mg–2Fe alloy by using additive manufacturing. Heterogeneous distribution of Fe, including a high number density of α-Al12(Fe,Mn)3Si particles distributed at the melting pool boundary and excessive Fe segregated along the cell boundaries that divided by Mg2Si eutectics, was verified as the beneficial factor for the alloy design and strength enhancement. In addition to the heterogeneous grains that contain fine cells, the interactions between dislocations and coherent Mg2Si eutectics and the α-Al12(Fe,Mn)3Si particles played an important role in improving the mechanical properties. This work represents a breakthrough in recycling high-strength Al alloys with extremely high Fe doping for green industrial application through additive manufacturing.

Distributions of Ni and Fe in the different tissues of snail Faunus ater and bivalve Psammotaea elongata

Gastropods Faunus ater and bivalves Psammotaea elongata were sampled from the intertidal waters of Pantai Sri Tujuh, Tumpat (Kelantan), and their different soft tissues and shells were determined for Ni and Fe. The outcomes showed that the shells of the two species had significantly (P&lt; 0.05) higher non-essential Ni levels than those in the different soft tissues. The contrary results were found in the essential Fe, where different soft tissues had significantly (P&lt; 0.05) higher Fe concentrations than those in the shells of the two molluscs. This phenomenon could be due to the different essentiality of the two different groups of Ni and Fes between the different soft tissues and shells of molluscs. The present finding indicated the shells of P. elongata and F. ater were storage sites for Ni.

Interzeolite conversion synthesized [Fe, Al]-FER zeolites with enhanced hydrothermal stability for NH3-SCR reaction

The [Fe, Al]-FER zeolites, which are prepared from the interzeolite conversion method (from MWW to FER topology) with high Al and Fe content (Si/Al of 8–18 and Si/Fe of 11–13), exhibit excellent catalytic performances and hydrothermal tolerance for NH3-SCR reaction. The interzeolite conversion process can be tuned by optimizing the zeolite synthesis conditions such as synthesis gel composition, crystallization time, crystallization temperature, and adding MWW seeds. The work can provide a new strategy to synthesize high Al and Fe content zeolite with high hydrothermal stability for NOx removal.

Use of thermally activated Fenton sludge for Cd removal in zinc smelter wastewater: Mechanism and feasibility of Cd removal

Fenton sludge is a byproduct of the Fenton process that contains large amounts of Fe and Ca. Because of the secondary contamination generated during the disposal of this byproduct, ecofriendly treatment methods are needed. In this study, we used Fenton sludge to remove the Cd discharged from a zinc smelter factory, using thermal activation to enhance the Cd adsorption capacity. Among the various temperatures considered (300–900 °C), the Fenton sludge that was thermally activated at 900 °C (TA–FS–900) adsorbed the highest amount of Cd because of its high specific surface area and high Fe content. Cd was adsorbed onto TA–FS–900 via complexation with C–OH, C–COOH, FeO−, and FeOH and cation exchange with Ca2+. The maximum adsorption of TA–FS–900 was 260.2 mg/g, indicating that TA–FS–900 is an efficient adsorbent, comparable to those reported in the literature. The initial Cd concentration in the zinc smelter wastewater discharged was 105.7 mg/L, 98.4% of which was removed by applying TA–FS–900, suggesting the applicability of TA–FS–900 for real wastewater containing high concentrations of various cations and anions. The leaching of heavy metals from TA–FS–900 was within the EPA standard limits. We concluded that the environmental impact of Fenton sludge disposal can be reduced, and the use of Fenton sludge can add value to the treatment of industrial wastewater in terms of the circular economy and environment.

Water quality assessment and pollution of Akarçay River, Türkiye

River water is a vital source of agricultural activities and ecology in the Akarçay basin. This study aims to determine the water quality of the Akarçay River. According to this purpose, 12 water samples that were thought to be affected by different polluting sources were taken through the flow path of the river and physicochemical analyses were performed. The water quality index (WQI) was used for drinking purposes, and the analysis results were compared with World Health Organization and Turkish drinking water standards. Irrigation quality parameters like sodium absorption ratio, residual sodium carbonate, and magnesium hazard were also calculated, showing that most samples are unsuitable for irrigation. The river water is of the Ca–Mg–HCO3, Na–Cl and Na–HCO3 types. It has been determined that the river water is unsuitable for irrigation and drinking water due to its high EC, Na+, Cl−, SO42−, As, B, F−, Fe, and Mn content. According to the WQI results, river water has different classifications from excellent to unsuitable. Geothermal water mixture and industrial, domestic and agricultural activities are the primary pollution sources. At the same time, the evaporation that the river is exposed to indicates the solute concentration and changes the usage characteristics.

Genetic mapping identified major main-effect and three co-localized quantitative trait loci controlling high iron and zinc content in groundnut.

Malnutrition is a major challenge globally, and groundnut is a highly nutritious self-pollinated legume crop blessed with ample genomic resources, including the routine deployment of genomic-assisted breeding. This study aimed to identify genomic regions and candidate genes for high iron (Fe) and zinc (Zn) content, utilizing a biparental mapping population (ICGV 00440×ICGV 06040;). Genetic mapping and quantitative trait locus (QTL) analysis (474 mapped single-nucleotide polymorphism loci; 1536.33cM) using 2 seasons of phenotypic data together with genotypic data identified 5 major main-effect QTLs for Fe content. These QTLs exhibited log-of-odds (LOD) scores ranging from 6.5 to 7.4, explaining phenotypic variation (PVE) ranging from 22% (qFe-Ah01) to 30.0% (qFe-Ah14). Likewise, four major main effect QTLs were identified for Zn content, with LOD score ranging from 4.4 to 6.8 and PVE ranging from 21.8% (qZn-Ah01) to 32.8% (qZn-Ah08). Interestingly, three co-localized major and main effect QTLs (qFe-Ah01, qZn-Ah03, and qFe-Ah11) were identified for both Fe and Zn contents. These genomic regions harbored key candidate genes, including zinc/iron permease transporter, bZIP transcription factor, and vacuolar iron transporter which likely play pivotal roles in the accumulation of Fe and Zn contents in seeds. The findings of this study hold potential for fine mapping and diagnostic marker development for high Fe and Zn contents in groundnut.

Iron from Lignite Mining Increases Phosphorus Fixation in Sediments, but Does Not Affect Trophic States of Lakes Along River Spree (Germany)

To mitigate lake eutrophication, phosphorus (P) availability can be managed by iron (Fe) amendments, which bind P in the water column and settle as Fe oxy-hydroxides. In the fluvial-lacustrine system Spree, Fe oxy-hydroxides enter lakes due to lignite mining in the Lusatian Area (NE Germany). We hypothesized that the amount of P that can be retained from the water column by sediments is positively correlated with their iron content. Column experiments were used to investigate uptake and release of P in the sediments under oxic and anoxic conditions in three downstream lakes (Lake Neuendorfer See, Lake Glower See, Lake Müggelsee) with decreasing mining influence and thus iron loads, and one nearby non-mining-affected lake (Lake Schwielochsee). In lakes interconnected by River Spree, the cumulative P uptake in sediments increased significantly with increasing sedimentary Fe concentrations under both oxic and anoxic conditions. Only the sediments of Lake Glower See had higher P uptake under anoxic than oxic conditions, most likely due to vivianite formation. The net P sedimentation was higher with higher Fe concentration and higher under oxic than anoxic conditions. However, the lakes are classified as eutrophic because although the sediments of the Spree lakes can store further P, this additional P uptake is of little relevance for the P budget in highly P-loaded lakes with short water residence times (10–100 d), as is typical for fluvial-lacustrine systems.