Ferrous Concentration Research Articles

Effect of Different Ferrous Concentrations on the Growth Characteristics of Genotypes of Sorghum bicolor L.

A field experiment was carried out during the fall season of the agricultural season 2022 AD at a research station of the Department of Field Crops, College of Agriculture - University of Tikrit in Salah al-Din Governorate, located at longitude 43.679 degrees east and latitude 34.616 degrees north of the equator in gypsum soil in order to know the effect of foliar feeding with two levels of Iron In addition to the comparison treatment, which is (0, 75, and 150) mg L on fivegenotypes of white corn, namely (J, Giza, Inqaz, Rabeh, and Li). Ferrous sulfate was used as a source of iron. Using the randomized complete block design (RCBD) with three replications, and each replicate contains (15) experimental units, each experimental unit contains four lines, the distance between one line and another is 60 cm, and between one line and another is 20 cm, to study growth characteristics. The Li variety was superior in leaf area and the percentage of iron in the leaves, reaching (4086.61 cm2 and 60.92 mg Fe/kg). As for the following characteristics, the number of days from sowing to 50% flowering and plant height, the J variety was superior to (99.11 days and 177.48 cm). and the characteristics, number of leaves per plant, estimation of chlorophyll A and estimation of chlorophyll B were lost The variety was superior to Giza, which reached (23.40 μg.cm2, 19.83 μg.cm2, and 16.43 leaves). As for the fertilizer additions, it was superior to (Fe2) and gave the highest averages in the characteristics of plant height, number of leaves per plant, leaf area, chlorophyll A, chlorophyll B, and iron content inthe leaves, as it reached 157.94 cm, 15.80 leaves, 3783.76 cm 2, and 23.34 μg. cm2 and 21.03 μg.cm2 and 64.38mg Fe / kg, respectively, and the addition of Fe (1)) in the characteristic of the number of days from sowing to 50% flowering exceeded 95.46%. The combination (Li + fertilizer additives (Fe2) was characterized by giving the highest averages in the characteristics of leaf area and the percentage of iron in the leaves. As for the characteristics, the number of days from cultivation until 50% flowering and plant height, it was outperformed by variety J + fertilizer additives (Fe2) and the characteristics of the number of leaves per plant Estimation of chlorophyll A and estimation of chlorophyll B were lostIt is superior to Giza + fertilizer additives (Fe2).

Genetic Heterogeneity of Genotypes of Sorghum under Different Ferrous Concentrations

A study was conducted of five genotypes of white corn (J, Giza, Inqaz, Rabeh, Li) in gypsum soil. The effect of foliar feeding with three levels of iron (0, 75 and 150) mg L was used (ferrous sulphate) on the growth of white corn at the plant. Research for the Department of Field Crops, College of Agriculture - University of Tikrit, for the fall season 2022 AD, with a sandy texture. As for the design type, random complete blocks (RCBD) with three replications, and each replicate contains (15) experimental units, each experimental unit contains four lines, the distance between one line and another is 60 cm, and between one line and another is 20 cm, to study growth characteristics. The Li variety excelled in the number of grains per head, head weight, weight of 1000 grains, grain yield per plant, total grain yield, harvest index, and the percentage of iron in the seeds, which amounted to (2316.0 seeds, 112.55 grams, 29.45 grams, 64.08 grams, 6.01 tons, 44.21%, and 67.75 mg Fe / kg), while the biological yield was superior to the J variety, which reached (12.93 tons). The percentage of protein was higher than the Giza variety, reaching (6.73%). As for fertilizer additions, (Fe2) was superior and gave the highest averages in traits, number of grains per head, head weight, weight of1000 grains, grain yield per plant, total grain yield, biological yield, harvest index, percentage of iron in seeds, andpercentage of protein, as it reached 2361.0 grains, 107.80 g, and 27. 43g, 64.67g, 5.33t, 12.20 tons, 44.26%, 72.75 mg Fe/kg, and 6.59%, respectively. The combination (Li + fertilizer additives (Fe2) was characterized by giving the highest averages in the characteristics of number of grains per head, weight of 1000 grains, grain yield per plant, grain yield, harvest index, and percentage of iron in seeds. The biological yield was outperformed by class J + additives Fertilizer (Fe1) and the characteristic of the percentage of protein was superior to the variety Giza + fertilizer additives (Fe2). The genetic variance contributed more than the environmental variance to all fertilizer additions (Fe2) and their quantitative characteristics, which was reflected in the degree of heritability in the broad sense, in addition to that the coefficient of genetic, environmental and phenotypic variation and the expected genetic improvement as a percentage was average for most of the traits under study.

Thermodynamic analysis and in situ PXRD study of mineralogy phase transformation of arsenopyrite in acid pressure oxidation

Acid pressure oxidation (POX) is a cost-efficient pre-treatment method for releasing refractory gold from arsenopyrite and pyrite prior to cyanidation. However, ongoing debate surrounds the mechanism of the dissolution, crystallization, and phase transformation during POX, in part due to the lack of thermodynamic data and in situ studies of the acid POX. In this study, we developed Eh-pH diagrams and used in situ powder X-ray diffraction (PXRD) to investigate mineralogical phase changes during acid POX of arsenopyrite. Based on the existing thermodynamic data, we established the Eh-pH diagrams for the Fe-As-S-H2O systems at 225 °C and 100 °C, which correctly predicted the predominant solid phases precipitating during POX of arsenopyrite at a pH range of 0 to 0.5, such as basic ferric sulphate (BFS: Fe(OH)SO4), szomolnokite (FeSO4·H2O), hydronium jarosite ((H3O)Fe3(SO4)2(OH)6) and angelellite (Fe4O3(AsO4)2). FeSO4·H2O solid is the stable phase during annealing stages as predicted by the Eh-pH diagram, which is in line with the observed solid phases using in situ PXRD. The influence of initial concentration of ferric ions and the presence of pyrite on mineral phase change was revealed. Our results confirmed the formation of FeSO4·H2O, BFS and hydronium jarosite during annealing stages, while BFS and/or hydronium jarosite dissolved during curing and cooling process. Especially, the formation of angelellite was observed in the presence of pyrite during cooling process, which is well-agreed with thermodynamic analysis.

Effect of Fe2+ on ANAMMOX Granular Sludge Cultured in a Biased Acidic Influent and Dynamic Environment

A continuous stirred tank reactor (CSTR) was utilized in this study to enrich and cultivate anaerobic ammonia oxidation process (ANAMMOX) granular sludge by gradually decreasing its pH, and to investigate the effects of different concentrations of ferrous ions (Fe2+) on the activity of ANAMMOX granular sludge cultivated under biased acidic conditions. The final nitrogen removal of ANAMMOX deteriorated at pH 6.30–6.50 after 220 days of continuous operation, but the nitrogen removal of ANAMMOX was favorable at pH 6.50–7.00. This indicates that a slightly acidic environment (pH = 6.50–7.00) promotes the activity of ANAMMOX, but the pH should not be too low (pH = 6.30–6.50). In the reactor, Candidatus Kuenenia was consistently the dominant ANAMMOX genus and its abundance declined from 11.70% on day 1 to 10.44% on day 220. As Fe2+ concentrations were increased (10, 20, 30 mg/L) in ANAMMOX granular sludge cultured in an acidic environment, the nitrogen removal effects gradually increased. In addition, with the increase in Fe2+ concentrations, the total nitrogen removal load (NRL) in the reactor was increased from 1.16 kg/(m3/d) to 1.42 kg/(m3/d). Increases in Fe2+ concentration did not result in inhibition of ANAMMOX, which may be attributed to the morphology of sludge and the shape of the reactor. As a result of the present study, new insights were gained into the physiological characteristics of ANAMMOX in an acidic environment over the long term, and how Fe2+ affects its ability to remove nitrogen from the environment.

Interaction of Ca2+ and Fe3+ in co-precipitation process induced by Virgibacillus dokdonensis and its application

Biomineralization has garnered significant attention in the field of wastewater treatment due to its notable cost reduction compared to conventional methods. The reinjection water from oilfields containing an exceedingly high concentration of calcium and ferric ions will pose a major hazard in production. However, the utilization of biomineralization for precipitating these ions has been scarcely investigated due to limited tolerance among halophiles towards such extreme conditions. In this study, free and immobilized halophiles Virgibacillus dokdonensis were used to precipitate these ions and the effects were compared, at the same time, biomineralization mechanisms and mineral characteristics were further explored. The results show that bacterial concentration and carbonic anhydrase activity were higher when additionally adding ferric ion based on calcium ion; the content of protein, polysaccharides, deoxyribonucleic acid and humic substances in the extracellular polymers also increased compared to control. Calcium ions were biomineralized into calcite and vaterite with multiple morphology. Due to iron doping, the crystallinity and thermal stability of calcium carbonate decreased, the content of OC = O, NC = O and CO-PO3 increased, the stable carbon isotope values became much more negative, and β-sheet in minerals disappeared. Higher calcium concentrations facilitated ferric ion precipitation, while ferric ions hindered calcium precipitation. The immobilized bacteria performed better in ferric ion removal, with a precipitation ratio exceeding 90%. Free bacteria performed better in calcium removal, and the precipitation ratio reached a maximum of 56%. This research maybe provides some reference for the co-removal of calcium and ferric ions from the oilfield wastewater.

A high productivity bioprocess for obtaining metallic copper from printed circuit boards (PCBs)

PCBs constitute a residue rich in metals, among which copper stands out due to its majority content, much higher than that found in natural deposits, so that it is a potential secondary resource. Many attempts have been made to recover copper via biohydrometallurgy because it is an environmentally friendly route, however, one of its main drawbacks is the low productivity achieved.A global process based on circularity for obtaining copper cathodes from PCBs is proposed. First, PCBs from end-of-life mobile phones are shred to sizes between 800 and 2000 µm. Copper is leached from these pieces in a continuous stirred tank reactor (CSTR) at high ferric concentration, at a moderate temperature of 60 °C reaching dissolution rate higher than 1 g/L·h and a yield of 99 %. The solution that leaves the CSTR with concentrations of up to 10 g/L of Cu is passed through a high-performance bioreactor for the regeneration of Fe(III). A biooxidation rate of 1.3 g/L⋅h was achieved, and no inhibition was observed.Concurrently, copper is recovered in metallic state by solvent extraction and electrowinning with recirculation streams becoming a more profitable and sustainable complete global process.

Modeling of asphaltic sludge formation during acidizing process of oil well reservoir using machine learning methods

Considering the global need for fossil fuels and its limited resources, maximum production from oil reservoirs is important. Acid treatment is a common method to stimulate oil reservoirs, but acid and oil interaction may form undesirable asphaltic sludge, and the prediction of this phenomenon by using machine learning models can be useful for field application. In this study, multi-layer perceptron (MLP), extreme gradient boosting (XGBoost), random forest (RF), and categorical boosting (CatBoost) as four machine learning models were employed to estimate the weight of asphaltic sludge formed. To this end, a data set containing 199 experimental data for seven different oil samples including a wide range of SARA fractions was used. The input parameters of the models included oil properties, acid properties, and the content of protective additives. The statistical analysis indicated that the MLP model has the highest accuracy with the coefficient of determination (R2) of 0.9517. In addition, the impact analysis of the input variables showed that the ferric ion concentration has the highest impact on asphaltic sludge formation with a relevance factor of 0.2755. Finally, using the leverage method, only 4 outlier data points were identified, which proved the validity of the model.

Angiotensin IV ameliorates doxorubicin-induced cardiotoxicity by increasing glutathione peroxidase 4 and alleviating ferroptosis

BackgroundDoxorubicin (DOX)-induced cardiotoxicity is an important cause of poor prognosis in cancer patients treated with DOX. Angiotensin IV (Ang IV) has multiple protective effects against cardiovascular diseases, including diabetic cardiomyopathy and myocardial infarction, but its role in DOX-induced cardiotoxicity is currently unclear. In this study, we investigated the effects of Ang IV on DOX-induced cardiotoxicity. MethodsThe viability of primary cardiomyocytes was measured by Cell Counting Kit-8 assays and Hoechst 33342/propidium iodide staining in vitro. ELISAs (serum cTnT and CK-MB) and echocardiography were performed to assess myocardial injury and cardiac function in vivo. Phalloidin staining, haematoxylin and eosin staining and wheat germ agglutinin staining were conducted to detect cardiomyocyte atrophy. We also performed C11 BODIPY staining, measured the levels of Ptgs2 and malondialdehyde and detected the concentrations of ferrous ions, glutathione and oxidized glutathione to indicate ferroptosis. ResultsAng IV not only attenuated DOX-induced atrophy and cardiomyocyte injury in vitro but also alleviated myocardial injury and improved cardiac function in DOX-treated mice in vivo. Moreover, Ang IV reversed DOX-induced downregulation of glutathione peroxidase 4 (GPX4) and inhibited ferroptosis both in vitro and in vivo. Knockdown of GPX4 by siRNA abolished the cardioprotective effects of Ang IV. Furthermore, Ang IV increased GPX4 levels and ameliorated ferroptosis in RAS-selective lethal 3-treated primary cardiomyocytes. ConclusionsAng IV ameliorates DOX-induced cardiotoxicity by upregulating GPX4 and inhibiting ferroptosis. Ang IV may be a promising candidate to protect against DOX-induced cardiotoxicity in the future.

Evaluation of manganese bioleaching and silver extraction in mining tailings by native bacteria using a flooded system

During the silver extraction process in mining, the generated residues (called tailings) still contain approximately 100-140 g/ton of silver due to the presence of refractory materials that trap this metal and prevent its solubilization by conventional methods. These residues can be treated by biohydrometallurgical processes allowing, together with the cyanidation process, an increase in the efficiency of silver extraction by eliminating refractory materials such as manganese, which is present as pyrolusite (MnO2, 3.78 %). Pyrolusite can change from manganese (IV) to manganese (II) when solubilized by bioleaching. This research analyzed the effects of bioleaching using native bacteria on the concentration of silver extraction from the removal of manganese in mining tailings. The native bacteria ITDBC2, ITDBC5, and ITDBC6 were identified as Leptospirillum ferriphilum by amplification of the 16S gene corroborated by bioinformatic analysis. The experimentation was carried out using a flooded bioleaching system (9.43 L) to resemble the industrial geometry with the following variables: concentration of ferrous ions (2, 7, and 14 g/L), pH (2, 4, and 6) and agitation time at 100 rpm (2, 4 and 6 min/day). The experimentation lasted 18 days. The removal of manganese and silver extraction was 71.84 and 55.53 %, respectively. The scaled-up of the evaluated bioprocess could reduce energy consumption and process larger amounts of pulp than the reported at the laboratory scale.

Iron Stress Testing of Oilfield Produced Waters and Hydraulic Fracturing Fluids in the Bakken

Friction reducers are a major additive in almost all water-based hydraulic fracturing fluids. Despite the important role they play in friction reduction during hydraulic fracturing, they pose a veritable threat to the permeability of tight reservoirs upon precipitation. In the industry today, the potential for such precipitation is seldom assessed and as a result, an additional contributor to the formation damage problem has been given little attention. In this work, the sensitivity and affinity of friction reducers to very low concentrations of ferric ions are exploited to provide a qualitative assessment of their propensity to precipitate in hydraulically fractured hydrocarbon reservoirs. Representative samples of produced water and a routinely utilized hydraulic fracturing fluid recipe were spiked with 50ppm Iron (III) trichloride and incubated for 24 hours in a water bath at 200 degrees Fahrenheit. The results showed that precipitation of friction reducers in fracturing fluid is highly likely at low concentrations of ferric ions. This precipitate formed turned from yellow to brown color over time upon heating. The test showed presence of fragmented/unfragmented Partially Hydrolyzed Polyacrylamide (PHPAM) in the produced water, with varying degrees of FR gel precipitation depending on the processing treatment given to the water used for hydraulic fracturing. Evidence for the presence of partially hydrolyzed polyacrylamide was demonstrated in one of the produced waters while the rest did not produce any discernable precipitates. The results indicate that formations with lower iron concentrations may be more vulnerable to Fe3+-PHPAM precipitation than those with higher ferric ion concentration. Therefore, to mitigate formation damage through precipitation of FRs during hydraulic fracturing, a routine iron stress test like the one described herein is required on both hydraulic fracturing fluid and produced water to determine the vulnerability of the reservoir to formation damage by fragmented/unfragmented anionic PHPAMs.

Influence of iron nanoparticles on rice (Oryza sativa) plant growth and yields

Alleviating iron (Fe) deficiency in soil and enhancing Fe content in edible portions by using conventional supplements pose challenges. In this context, a greenhouse experiment was conducted during the kharif season of 2018 to evaluate the impact of iron dose and source, specifically nano Fe2O3 and FeSO4, on rice root growth and yields. Results showed that foliar application of 0.2% Fe through FeSO4 and 0.2% Fe through nano Fe2O3 significantly increased the mean root length by 9.5% and 10.1%, respectively, alongside increasing the mean root surface area by 8.8% and 7.3%, respectively, over control. However, the soil application of Fe (3 mg Fe/kg and 0.6 mg Fe/kg through nano Fe2O3 was ineffective in enhancing the rice root length and surface area. In contrast to the root parameters, nano Fe2O3 treatment did not have any significant improvement in grain and straw yield. The addition of Fe through FeSO4 .7H2O led to a noteworthy 24% and 33% increase in grain yield at 0.2% Fe (foliar) and 15 mg Fe/kg (soil), respectively. Similarly, the straw yield saw a corresponding increase of 39% and 34%, respectively, over control. Moreover, the application of FeSO4 and nano Fe2O3 resulted in Fe content registering 1.89 and 1.50 times higher than the control (93 mg/kg). Conversely, lower doses of nano Fe2O3 exhibited no influence on ferrous ion content, DTPA-Fe levels, or yield through both foliar and soil applications.

Modelling the scale-up of the iodine-assisted chalcopyrite leaching in ferric sulfate media from reactors to columns and simulating heap operations

The iodine-assisted heap leaching of chalcopyrite involves the addition of iodide in ferric sulfate media to accelerate the dissolution of chalcopyrite at ambient temperature. The previous studies using reactor leaching tests identified the solution potential, the amount of iodide added, and temperature as the factors controlling the process performance. In the present study, the iodine-assisted chalcopyrite leaching process was scaled up from reactors to 1-m and 6-m columns to further understand how these parameters control the process performance at a larger scale. This is essential to optimize the process in industrial-scale heap leach pads. The HeapSim-2D model was calibrated with the 1-m and 6-m column leach tests together with the kinetic parameter values obtained in the previous reactor leaching tests. When the iodine-assisted chalcopyrite leaching was scaled up from reactors to 1-m and 6-m columns, the leaching became slower because the ore used in the column leaching tests had larger particle sizes with partially-liberated chalcopyrite particles. The calibrated model was then used to carry out the sensitivity analyses to assess the response of the process performance to key design and operating variables, including irrigation rate, ferric concentration, total iodide concentration, temperature, and heap height. The analyses show that the copper extraction could be optimized by adjusting these key design and operating parameters.

Kinetic isotope effect study of N-6 methyladenosine chemical demethylation in bicarbonate-activated peroxide system.

N-6 methyladenosine is the most abundant nucleic acid modification in eukaryotes and plays a crucial role in gene regulation. The AlkB family of alpha-ketoglutarate-dependent dioxygenases is responsible for nucleic acid demethylation. Recent studies have discovered that a chemical demethylation system using hydrogen peroxide and ammonium bicarbonate can effectively demethylate nucleic acids. The addition of ferrous ammonium sulfate boosts the oxidation rate by forming a Fenton reagent with hydrogen peroxide. However, the specific mechanism and key steps of this process remain unclear. In this study, we investigate the influence of ferrous ammonium sulfate concentration on the kinetic isotope effect (KIE) of the chemical demethylation system using LC-MS. As the concentration of ferrous ions increases, the observed KIE decreases from 1.377 ± 0.020 to 1.120 ± 0.016, indicating a combination of the primary isotope effect and inverse α-secondary isotope effect with the ion pairing effect. We propose that the initial hydrogen extraction is the rate-limiting step and observe a tight transition state structure in the formation of the hm6A process through the analysis of KIE trends. The concentration-dependent KIE provides a novel perspective on the mechanism of chemical demethylation and offers a chemical model for enzyme-catalyzed demethylation.

Effects of ferrous addition to Vallisneria natans: An attempt to apply ferrous to submerged macrophyte restoration

Restoration of submerged macrophytes is an efficient way for endogenous nutrient control and aquatic ecological restoration, but slow growth and limited reproduction of submerged macrophytes still exist. In this research, the effect of ferrous on the seed germination and growth of Vallisneria natans (V. natans) were studied through aquatic simulation experiments and its influence on the rhizosphere microbial community was also explored. The seed germination, growth, and physiological and ecological parameters of V. natans were significantly affected by the ferrous treatments. Ferrous concentration above 5.0 mg/L showed significant inhibition of seed germination of V. natans and the best concentration for germination was 0.5 mg/L. During the growth of V. natans, after ferrous was added, a brief period of stress occurred, which then promoted the growth lasting for about 19 days under one addition. The diversity and richness of the rhizospheric microbial were increased after the ferrous addition. However, the function of the rhizospheric microbial community showed no significant difference between different concentrations of ferrous adding in the overlying water. Ferrous addition affected the growth condition of plants (content of CAT, Chl a, Chl b, etc.), thus indirectly affecting the rhizospheric microbial community of V. natans. These impacts on V. natans and rhizosphere microorganisms could generalize to other submerged macrophytes in freshwater ecosystems, particularly which have similar habits. These findings would contribute to the ecological evaluation of ferrous addition or iron-containing water, and provide a reference for submerged macrophytes restoration and ecological restoration in freshwater ecosystems.

Metronomic capecitabine with rapamycin exerts an immunosuppressive effect by inducing ferroptosis of CD4+ T cells after liver transplantation in rat

Liver transplantation is one of the most effective treatments for hepatocellular carcinoma (HCC). The balance between inhibiting immune rejection and preventing tumor recurrence after liver transplantation is the key to determining the long-term prognosis of patients with HCC after liver transplantation. In our previous study, we found that capecitabine (CAP), an effective drug for the treatment of HCC, could exert an immunosuppressive effect after liver transplantation by inducing T cell ferroptosis. Recent studies have shown that ferroptosis is highly associated with autophagy. In this study, we confirmed that the autophagy inducer rapamycin (RAPA) combined with metronomic capecitabine (mCAP) inhibits glutathione peroxidase 4 (GPX4) and promotes ferroptosis in CD4+ T cells to exert immunosuppressive effects after rat liver transplantation. Compared with RAPA or mCAP alone, the combination of RAPA and mCAP could adequately reduce liver injury in rats with acute rejection after transplantation. The CD4+ T cell counts in peripheral blood, spleen, and transplanted liver of recipient rats significantly decreased, and the oxidative stress level and ferrous ion concentration of CD4+ T cells significantly increased in the combination group. In vitro, the combination of drugs significantly promoted autophagy, decreased GPX4 protein expression, and induced ferroptosis in CD4+ T cells. In conclusion, the autophagy inducer RAPA improved the mCAP-induced ferroptosis in CD4+ T cells. Our results support the concept of ferroptosis as an autophagy-dependent cell death and suggest that the combination of ferroptosis inducers and autophagy inducers is a new research direction for improving immunosuppressive regimens after liver transplantation.

Total flavonoids of Rhizoma drynariae influence ferroptosis in osteoblasts via miR-205-5p/GPX4 axis

Purpose: This research investigated the biological effects of total flavonoids of Rhizoma Drynariae (TFRD) on osteoporosis in mice.Methods: Mice were subjected to bilateral ovariectomy (OVX) to generate the osteoporosis model used, which was then intragastrically administered TFRD daily at a dose of 75 mg/kg. Bone loss was examined histologically using H&E staining. Moreover, erastin-treated primary osteoblasts were used to further analyze the effect of TFRD on ferroptosis. Reactive oxygen species (ROS), ferrous iron level, and CCK-8 method were employed to determine the protective influence of TFRD against ferroptosis in erastin-treated osteoblasts. The relationship between microRNA-205-5p (miR-205-5p) and glutathione peroxidase 4 (GPX4) was determined using luciferase assay.Results: TFRD treatment inhibited OVX-induced bone mass loss, downregulated ferrous ion content, and increased the level of GPX4 in vivo (p < 0.01). Besides, TFRD treatment inhibited erastin-induced increases in ROS level and ferrous iron level, and promoted cell viability in vitro (p < 0.01). Moreover, TFRD increased GPX4 protein expression level (p < 0.01). Results from gain and loss experiments showed that GPX4 increased cell viability, and reduced ferrous ion and ROS levels in erastin-induced osteoblasts (p < 0.01, p < 0.001, respectively). Furthermore, miR-205-5p directly targeted GPX4 and negatively regulated GPX4 expression (p < 0.01, p < 0.001, respectively). Upregulation of GPX4 reversed the effect of miR-205-5p overexpression on cell viability, and reduced ferrous iron level and ROS levels in osteoblasts significantly.Conclusion: TFRD may serve as an inhibitor of osteoblast ferroptosis during osteoporosis formation by down-regulating the expression of miR-205-5p which directly targets GPX4 in mouse osteoblasts. These findings indicate the therapeutic potential and underlying mechanism of action of TFRD.

Revealing methane production potential from waste activated sludge through citric acid-assisted hydrogen corrosion of zero valent iron

Anaerobic digestion of waste activated sludge (WAS) for biofuel recovery is one key step for developing energy-self-sufficient and carbon–neutral wastewater treatment plants. Although zero valent iron (ZVI) is an alternative additive to promote methane production from WAS, low hydrogen corrosion of ZVI is one important limitation. This study explored whether methane production potential could be further enhanced while using citric acid (CA) to accelerate hydrogen corrosion of ZVI. Results showed that the maximum methane production reached 92.77 mL/g volatile suspended solid (VSS) with ZVI of 30 mM and CA of 6 mM, which increased by 63.8% compared to that with solo ZVI. Mechanism analysis demonstrated that the proposed strategy could accelerate the solubilization of WAS, increase the accumulation of short-chain fatty acids (SCFAs), and optimize the composition of SCFAs. Meanwhile, both the efficiencies of hydrogen yield and production rate obtained with ZVI and CA were the highest. The accumulation of hydrogen with ZVI and CA reached 5 mL/g VSS during the 9-hour period, which was 2.42 times higher than that with solo ZVI, and the hourly hydrogen production rate was 2.47 mL/g VSS−1h−1, which was higher than those with either solo CA or ZVI. Thus, the effectiveness of 1 + 1＞2 was obtained. Correspondingly, the concentration of ferrous ion with ZVI and CA increased to 2.32 times higher than that with solo ZVI. In addition, the microbial community analysis indicated that hydrogenotrophic methanogens were predominated with ZVI and CA. These findings may provide some new solutions for promoting the role of nano-ZVI in enhancing methane production from anaerobic digestion.

Ductile Iron: A Low-Cost Optimal Anode Material for Electrochemical Generation of Ferrate(VI)

The effects of anode composition and temperature on anode electrochemical properties, the passivation layer’s structure, and ferrate(VI) generation in 14 M NaOH were investigated. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic polarization (GP) were used to analyze the electrochemical processes involving the electrosynthesis of ferrate using some low-cost anode materials: ductile iron, grey cast iron, and mild steel. The results proved that the presence of silicon and graphite with sphere form in the ductile iron anode significantly increased ferrate electro-generation. The optimal temperature for the electro-generation of ferrate was 30 °C–40 °C. The current efficiency using the ductile iron anode was constantly at least about 30% superior to that of the grey cast iron and mild steel electrodes. The ductile iron anode material was the most feasible option because it provides the highest ferrate concentration (1.58 g L−1) with the highest current efficiency of 74% and the lowest specific energy consumption of 1.2 kWh kg−1 ferrate.

Polarization Curve of Chloride-Induced Corrosion in Steel Using a Three-Dimensional Model

Corrosion process occurs naturally in which metals, such as steel, undergo degradation due to chemical or electrochemical reactions with their surroundings. This however can lead to serious malfunctions and costly damages to crucial steel uses. In marine activities, most metals and alloys used inevitably degrade since the sea is rich in corrosive electrolytes, in particular, chloride. This may lead to the occurrence of pitting corrosion, which is highly localised and can cause major catastrophes. Hence, it is important to understand the science of pitting corrosion which in turn can benefit corrosion control processes. This can be done through simulation of pitting activities. In this study, a three-dimensional model of a minute pit in steel, immersed in sodium chloride solution in water, is simulated using COMSOL Multiphysics version 5.6 with Chemical Reaction Engineering Module. The simulation is run to observe the shape of the polarization curve at the actively corroding pit. The initial pH of the immersing solution is at a slightly alkaline condition, namely at pH 8. The results show that the corrosion potential, Ecorr, of a point at the bottom of the corroding pit is -0.74 V. The model is also able to show a high concentration of ferrous ions, Fe2+, inside the pit geometry, reaching to a value of 2.5×103 mol m-3. These results indicates that metal dissolution occurs. The shape of the polarization curve obtained in this study exhibits a significant linkage to the propagation of pit, which in turn indicates the type of corrosion a pit can evolve into, in particular, pitting corrosion.

Evaluation of ferric ion molar concentration effect on morphological and opto-electrochemical properties of FexNi1-xO composite thin films

The impact of a significantly lower ferric (Fe3+) ion concentration on the structural, morphological, optical, and electrochemical properties of spin-coated FexNi1-xO thin films cast on Indium Tin Oxide (ITO) glasses was scrutinized and then compared with a higher ferric (Fe3+) ion concentration. After a careful structural study of the FexNi1-xO thin films by X-ray diffraction (XRD) analysis, the film surface was further analyzed by atomic force microscopy (AFM), field emission scanning electron microscopy (FE-SEM) study, and X-ray photoelectron spectroscopy (XPS). Even for a noticeably small amount of substituted Ni2+ metal cations by Fe3+, degradation of the host crystal lattice was surprisingly higher. The influence of Fe3+ ions on the optical properties of FexNi1-xO ITO thin films was studied using UV–visible absorption spectra and Raman spectra. Both unsubstituted and Fe-substituted NiO ITO thin films showed photoluminescence properties. Changes in resistance values in pristine and FexNi1-xO thin films were monitored by an electrochemical impedance spectroscopy (EIS) study. Fe-substituted NiO thin films with a lower molar concentration showed better electrochemical performance as compared to those with a higher molar concentration of Fe3+ ions. This fact was further reinforced through a current-voltage (IV) study and a cyclic-voltagram (CV) study.