Iron Removal Research Articles

Bioenergy-producing two-stage septic tank and floating wetland for onsite wastewater treatment: Circuit connection and external aeration

This study designed a two-stage, electrode-integrated septic tank-floating wetland system and assessed their pollutant removal performances under variable operational conditions. The two-stage system achieved mean organic, nitrogen, phosphorus, and coliform removal percentages of 99, 78, 99, and 97%, respectively, throughout the experimental run. The mean metals (chromium, cadmium, nickel, copper, zinc, lead, iron, and manganese) removal percentages ranged between 81 and 98%. Accumulated sludge, filler media, and the hanging root mass contributed to pollutant removals by supporting physicochemical and biological pathways. The mean effluent organic concentration and coliform number across the two-stage system were 20 mg/L and 1682 CFU/100 mL, respectively, during the closed-circuit protocol, which was beneath the open-circuit-based performance profiles, i.e., 32 mg/L and 2860 CFU/100 mL, respectively. Effluent organic, nitrogen, phosphorus, metals, and coliform number ranges across the two-stage system were 9–17 mg/L, 13–24 mg/L, 1–1.5 mg/L, 0.001–0.2 mg/L, and 1410–2270 CFU/100 mL, respectively during intermittent and continuous aeration periods. The air supply rate differences influenced pollutant removal depending on the associated removal mechanisms. The non-aeration phase produced higher effluent pollutant concentrations than the aeration periods-based profiles. The overall mean power density production of the septic tank ranged between 107 and 596 mW/m3; 110 and 355 mW/m3 with the floating wetland. The bioenergy production capacity of the septic tank was positively correlated to external air supply rates. This study demonstrates the potential application of the novel bioenergy-producing septic tank-floating wetland system for wastewater treatment in decentralized areas.

Predictive thermodynamic model for solvent extraction of Iron(III) by tri-n-butyl phosphate (TBP) from chloride media

Hydrometallurgical processes are crucial to reducing the environmental impact of metal recovery, yet dealing with iron impurities is a major challenge. This paper presents a semi-empirical predictive thermodynamic model for iron removal from chloride media by solvent extraction with tri-n-butyl phosphate (TBP). This model is built upon the OLI mixed-solvent electrolyte framework (OLI-MSE). It goes beyond traditional thermodynamic models by incorporating the non-ideality of both the aqueous and organic phases in a single, chemistry-based thermodynamic model. On top of the OLI-MSE framework lies the chemical model that depicts the extraction of Fe(III) by forming an ion pair between the FeCl4– anion and protonated TBP (TBPH+) in the organic phase. The iron(III)-containing ion pair in the organic phase is further stabilized by interactions with neutral TBP molecules. Developing the model required modeling the Fe(III) – chloride chemistry in the aqueous phase, optimizing the HCl extraction model, and fitting the parameters between FeCl4–, TBPH+, and TBP to experimental solvent extraction data. The resulting thermodynamic model can predict the solvent extraction of iron(III) from complex feed solutions by TBP in aliphatic diluents at all concentrations up to undiluted TBP. It can be used to calculate the equilibrium energies and composition, and the species present at equilibrium.

Carboxymethyl cellulose enhanced Cr(VI) removal of zero-valent iron via the coating anti-passivation mechanism

Competition for electrons from dissolved oxygen and secondary passivation resulting from the deposition of FeCr hydroxide are two challenges that impede the removal of hexavalent chromium (Cr(VI)) with zero-valent iron (ZVI). In this study, we fabricated micron-sized zero-valent iron modified with carboxymethyl cellulose (CMC-ZVI) via a mechanical ball milling process and demonstrated its improved performance up to eight times for Cr(VI) removal. Owing to the CMC protective film, the inhibition of dissolved oxygen for Cr(VI) removal, aging of ZVI in air, and secondary passivation of ZVI by the deposition of FeCr hydroxides were all inhibited. Even after a week of continuous aging, the CMC-ZVI maintained a stable Cr(VI) removal efficiency of over 50%. The excellent hydrophilicity of CMC enhanced the interaction of CMC-ZVI with water and Cr(VI), thus improving its capacity for Cr(VI) removal. Furthermore, CMC-ZVI not only proficiently reduced and completely removed the high-mobility Cr(VI) from actual electroplating effluent, but also effectively alleviated the inhibition of Cr(VI) removal via CMC-ZVI by aeration and air aging. The efficiency of CMC-ZVI in removing Cr(VI) from actual electroplating effluent was improved by over 41 times compared to pristine ZVI. This advantage has the potential to make the storage and transportation of ZVI more affordable and convenient and increases its potential for practical applications. This study provides an efficient Cr(VI) removal strategy using ZVI for environmental remediation and a strategy for the production of highly reactive, aging-resistant, easily stored, and transported zero-valent iron with the potential for practical applications.

Impact of design aspects on iron removal efficiencies from coal mine drainage in full-scale lagoons

In response to the potential ecological problems caused by coal mine drainage, passive Mine Water Treatment Schemes (MWTS), consisting of settlement lagoons and aerobic wetlands, are developed to remove iron and other contaminants prior to discharge into the environment. Existing research has examined individual design aspects separately, addressing the effect of lagoons' design on treatment performance. However, long-term research lacks data on the design aspects of full-scale mine drainage lagoons, to ensure consistent iron removal and optimal treatment of the mine drainage. This study analysed and assessed the design aspects of five full-scale lagoons, alongside monthly iron concentrations spanning over a period of twelve years, aiming to evaluate lagoon treatment performance based on different design aspects. Correlation and regression analyses were conducted to offer a better understanding of the potential relationships between iron removal efficiencies and the various design aspects of lagoons.Results indicated that the mean iron removal efficiencies of the lagoons studied, ranged from 25.12% to 92.85%, being impacted by the different design features. The correlation and multiple regression analysis results suggest that operational Water Levels, Surface Area, Aspect Ratio, layout and number of inlets and outlets, as well as shape of the lagoons affected iron removal (R2 0.78, p-value <0.05). Lagoons with larger aspect ratio were observed to have performed better in removing iron. In addition, a reduction in operational water level was observed to lead to increased iron removal. Furthermore, the result of the regression analysis demonstrated that the age of the lagoon significantly affects its treatment performance. Overall, lagoons with mid-mid configuration, multiple inlets and outlets and aspect ratio of 4 are found to allow for better flow and contaminant spread within the system, ensuring better adsorption and optimal removal of iron, although subject to regular ochre removal. This study offers valuable insights to lagoons design engineers, research scientists, policy makers and MWTS operators to optimize treatment performance.

Assessment of the suitability of greensand filtration for Mn removal for private wells

Greensand filtration is a common treatment option for manganese, sulfide, and iron removal; poor maintenance, however, can compromise effectiveness and even lead to increased post-treatment Mn concentrations. A private drinking-water well in exceedance of Health Canada’s maximum allowable concentration for Mn was sampled over a 1-year period to assess Mn removal via greensand filtration. Mn concentrations post-treatment were on average twofold higher than raw well water prior to media change. Reducing conditions, evidenced by negative oxidation–reduction potential (ORP) of the effluent, were central to generating soluble Mn(II). Monitoring revealed that water usage patterns caused variability in post-treatment Mn, with peak concentrations (&gt;3.5× higher than influent water) observed after a 7-day idle period. As inadequate oxidant addition can lead to reducing conditions, monitoring ORP may facilitate proxy surveillance for Mn release. Findings underscore the importance of human factors (e.g., aesthetic concerns, barriers to maintenance, perceived risk) when evaluating overall benefits and drawbacks of treatment systems.

Activation of periodate by iron-containing sludge from groundwater treatment plants for degradation of methylene blue in wastewater

Currently, there are well-operated iron removal water plants in the northeast region of China. Among them, the backwash process produces a large amount of iron-containing sludge (IS) year by year, which can cause some harm to the environment if not treated. The main form of existence for IS is amorphous γ-FeOOH, and this work demonstrates that IS is a natural and highly active catalyst for periodate(PI). Moreover, IS showed strong stability in environmental factor effects and reproducibility experiments. EPR with quenching experiments proved that IS could activate PI to produce •OH, O2•−, 1O2, and IO3•. In the degradation experiments where methylene blue was chosen as the model pollutant, IO3•, and 1O2 were the substances that served the prominent role in degradation. This work provides an inexpensive and feasible way to dispose of waste iron-containing sludge from water plants and provides fundamental insights into the degradation mechanism of organic pollutants through the activation of PI by IS.

Recovery of high-grade cobalt oxide from zinc plant residue (ZPR) generated at zinc processing plants

In the present study, a method for cobalt recovery from Zinc Plant Residue (ZPR) has been developed. First, the residue was leached in a dilute sulfuric acid solution. >90% cobalt and 95% zinc were leached in two hours at room temperature. Then, leach liquor was purified before cobalt precipitation. First, copper and cadmium were removed using zinc dust. >99% copper and 80% cadmium were removed in 30 min at room temperature with slow agitation. Then, dissolved iron was removed using sodium persulfate as an oxidizing agent, and lime was used to maintain pH. Iron was precipitated (∼99%) in 1 h at 60 °C temperature by maintaining pH at 3.5 and Eh at 700 mV. After iron removal, cobalt was precipitated by using sodium persulfate as an oxidizing agent, and sodium hydroxide was used to maintain pH. The cobalt precipitate was calcined and then the final product was obtained with 58% Co. The filtrate, obtained after cobalt precipitation, had a zinc concentration of approximately 69 g/L. About 82% cobalt and 90% zinc were recovered in the entire process.

Evaluation of operational efficiency and performance for a water treatment plant

The current study presents a comprehensive analysis of the operational efficiency and performance evaluation of the Hazelmere Water Treatment Plant over the period from 1999 to 2018. By focusing on the removal efficiencies of few parameters including iron (Fe), turbidity, and E. coli, the study provides valuable insights into the plant's ability to treat water effectively and produce high-quality drinking water. Leveraging data analysis techniques and computational tools, the research also explores the forecasting of water quality parameters beyond the study period, enhancing predictive capabilities for monitoring and managing water quality in the future. The Hazelmere Water Treatment Plant (WTP) has a daily capacity of 75 Ml it supplies water to the surroundings. Its intricate treatment process, featuring chemical dosing, clarification, filtration, and disinfection, operates harmoniously. The plant consistently exceeded global standards. Effluent turbidity consistently met stringent World Health Organization/South African National (WHO/SANS) discharge standards at ≤ 1 NTU. The turbidity removal efficiencies ranged from 65.88 to 99.61 % on average over the period from 1999 to 2018. Iron removal also adhered to WHO/SANS criteria, registering ≤ 2 mg/L. The removal efficiencies have ranged from 82 to 99% on average for the same period. Most impressively, E. coli removal efficiency maintained a flawless 100 % for the same period, indicating a pathogen-free effluent throughout the period, with a steady annual average of 0 MPN/100 m, some challenges have occurred including the contamination of the freshwater from the dam, the limited data availability, and issues related to sustainability and compliance. These challenges were overcome by using advanced tools for data analyses such as R package, developing a performance evaluation framework and establishing recommendations for the adoption of innovative technologies, and improvements in operation and maintenance practices. Overall, this study makes significant contributions to the field of wastewater treatment and water quality management, advancing our understanding of sustainable water resource management and environmental protection.

Evolution behavior of Fe and Fe-rich phases in high-Fe concentration Al-Si-Mg alloy with Mn, Cr, and Co alloyed

In this work, we report the evolution behavior of Fe and Fe-rich phases in the high-Fe concentration recycled Al-Si-Mg aluminum melt with and without alloying elements (Mn, Cr, Co) introduced. Firstly, the thermodynamic calculations reveal that the addition of Mn, Cr, and Co could improve the nucleation temperature of the Fe-rich phase. Moreover, four solidified ingots for Al-10Si-0.5Mg-1Fe alloy(base alloy) and the base alloy with 1.3 wt% Mn, 0.8 wt% Cr, and 0.8 wt% Co added, respectively, were prepared by holding the melt for 30 min at 610 ℃ after all the raw materials were fully melted. Microstructure examination revealed that the addition of Co resulted in the formation of the needle-like Fe-rich phase, which further leads to a poor settling effect and low iron removal efficiency. In contrast, the addition of Mn and Cr favors converting β-AlFeSi into α-AlFeMnSi, and forming the Chinese script and fish-bone Fe-rich phase. The size of the Fe-rich phase formed after adding Cr is smaller, while the residual Fe content after adding Mn is less. Also, the sludge phase at the bottom of the ingot presents a polygonal shape and long rod shape after adding Mn and Cr, respectively. Further, the Mn alloying increases the particle size of the sludge, while Cr refines the sludge phase and increases the aspect ratio (length/width ratio) of the sludge. Particularly, for Al-Si-Mg alloy with 1.0% Fe content, the superior mechanical properties are obtained by adding 0.8 wt% Cr, and the tensile strength reaches 136 MPa. After adding 1.3 wt% Mn, the Fe content of the upper section is reduced to 0.37 wt%, and the Fe removal rate achieves 63%. The obtained results provide some guidelines for achieving high iron separation efficiency in recycled aluminum-silicon alloy melts.

Research on Hydrothermal Iron Removal From Wet Zinc Refining Solutions and Iron Residue Reduces Emissions

For the conventional wet zinc refining processes of the jarosite method and goethite method of iron removal, the process that existed was iron residue low iron, high zinc, large amount of residue, and high cost of harmless treatment, this paper carried out a study on hydrothermal iron removal from wet zinc refining solutions and an iron residue that reduces emissions. The results show that the reaction temperature is a prerequisite for the precipitation of Fe3+ to precipitate hematite (Fe2O3). Prolonging the reaction time can induce the conversion of jarosite (KFe3(SO4)2(OH)6) to hematite. Increasing the partial pressure of oxygen will accelerate the oxidation of Fe2+ to Fe3+ and promote the formation of the hematite phase. Under the optimized technical parameters of reaction temperature 180 °C, oxygen partial pressure 0.6 MPa, reaction time 3 h, and controlled alkali metal ion concentration, 92.49% of the iron in the solution was precipitated into the residue in the form of hematite(Fe2O3), and the precipitated iron residue contained 57.75% iron and 0.82% zinc; compared with the jarosite process, the amount of iron residue was reduced by about 65%, and the zinc content of iron residue was reduced by 5.86%. The use of hydrothermal mineralization iron precipitation processes can realize the mineralization precipitation of iron in solution under low-acid conditions and obtain hematite iron precipitation residue with iron content up to the industry standard of iron oxide. And can be realized for resource utilization, helping the wet process zinc industry to develop in a green and low-carbon direction.

New hematite method: efficient and enhanced separation of rare earth and iron by alkaline regulation of pH in rare earth chloride solutions

Iron in RECl3 solutions is a detrimental impurity, adversely impacting both the purification efficiency of RECl3 and purity of rare earth compounds. RECl3 solutions employs the neutralization precipitation method for iron removal, leading to iron slag rich in valuable rare earth elements and radioactive thorium. This practice not only results in rare earth resource wastage but also poses significant ecological challenges. This study introduces an innovative hematite method for efficient and enhanced separation of rare earth and iron from RECl3 solutions. This method involves adjusting the solution's pH using alkali in a high-pressure reactor. Results indicate optimal conditions: a OH− to Fe3+ ratio of 1.5:1, temperature at 180°C, duration of 3 hours, and a Fe3+ (as Fe2O3) to Fe2O3 crystal seed molar ratio of 1:1. Under these conditions, the iron slag contains 1.3% REO and 63.69% TFe, with a rare earth loss rate of 0.35% and a TFe removal rate of 90.36%. Thermodynamic analysis reveals that at 25°C, ammonia water adjusts the pH of RECl3 solutions to 2-3, with the presence of Fe(OH)2+ and Fe(OH)2+ in the solution. The potential pH diagram of Ce-Fe-H2O at 180°C indicates that a pH range of -1.87 to 2.99 is crucial for Fe2O3 and Ce3+ formation. SEM analysis shows that the iron slag phase is a densely packed elliptical hematite sphere of approximately 1 micron and contains 0.36% thorium. This new hematite method using alkali-regulated high-temperature and high-pressure conditions for iron removal from RECl3 solutions not only minimizes rare earth loss but also mitigates iron slag's environmental impact. Furthermore, it offers a novel iron removal technique for the smelting industry.

Blood donation for iron removal in individuals with HFE mutations: study of efficacy and safety and short review on hemochromatosis and blood donation.

Elevated serum ferritin with/without HFE variants in asymptomatic persons leads frequently to referral for blood donation. Hemochromatosis (p.C282Y/p.C282Y) only requires treatment. We evaluated safety and feasibility of iron removal in healthy persons with elevated ferritin and HFE variants using blood donation procedures. Thirty subjects with ferritin >200 ng/mL (women) or >300 ng/mL (men) with p.C282Y/p.C282Y, p.C282Y/p.H63D or p.H63D/p.H63D were randomized to weekly phlebotomy (removal of 450 mL whole blood) or erythrapheresis (removal of 360 mL red blood cells) every 14 days. The ferritin target was <100 ng/mL. A full blood count and ferritin were measured at each visit. Hemoglobin (Hb) ≥140 g/L was required at inclusion. If Hb dropped to <120 g/L (women) or <130 g/L (men), procedures were postponed (7 or 14 days). Primary endpoint was the number of procedures needed to the ferritin target; secondary objectives were duration of treatment and compliance. The treatment effect was tested with Poisson regression; number of procedures and treatment duration were compared between study arms with the Kruskal-Wallis test. Twenty-five of 30 participants were men (83%); mean age was 47 years (SD 10.5), mean BMI 26.6 kg/m2 (SD 3.6); 17 had p.C282Y/p.C282Y, nine p.C282Y/p.H63D, four p.H63D/p.H63D. Median baseline Hb was 150 g/L (IQR 144, 1,559), median ferritin 504 ng/mL (IQR 406,620). Twenty-seven subjects completed the study. Treatment arm (p < 0.001) and HFE variant (p = 0.007) influenced the primary endpoint significantly. To ferritin levels <100 ng/mL, a median number of 7.5 (IQR 6.2, 9.8) phlebotomies and 4.0 (IQR 3.0, 5.8) erythraphereses (p = 0.001) was needed during a median of 66.5 days (IQR 49,103) and 78.5 days (IQR 46139), respectively (p = 0.448). Low Hb was the principal reason for protocol violation; anemia occurred in 13 participants (48%). Immediate complications were infrequent; fatigue was reported after 25% of phlebotomies and 45% of erythraphereses. Thirty-five procedures were postponed because of low Hb and 15 for non-medical reasons. The median interval was 7.0 (IQR 7.7) and 14.0 (IQR 14, 20) days between phlebotomies and erythraphereses, respectively. Blood donation procedures remove iron effectively in HC, but frequent treatments cause Hb decrease and fatigue that can impair feasibility.

A New Concept in Antidiabetic Therapeutics: A Concerted Removal of Labile Iron and Intracellular Deposition of Zinc.

A New Concept in Antidiabetic Therapeutics: A Concerted Removal of Labile Iron and Intracellular Deposition of Zinc.

Recovery of filler material from mining waste: Techno-economic, and kinetic study

This paper emphasizes the recovery of filler materials from bauxite mining waste by leaching iron oxides (Fe2O3). A combination of oxalic acid and hydrochloric acid is employed synergistically to facilitate the removal of iron oxides (Fe2O3) via the leaching process. Through optimization of the leaching process for iron oxide, it was determined that employing 2 M HCl along with 0.5 M oxalic acid at a temperature of 70°C for 240 minutes yielded a maximum iron removal efficiency of 64.32%. The resulting leached product met the standards outlined by the Bureau of Indian Standards (BIS) for utilization as a filler material. Kinetic investigation utilizing the shrinking core model revealed that the iron leaching process was primarily governed by a reaction step characterized by an activation energy (E) of 17.02 kJ/mol. Economic analysis indicated a return on investment of 523.65%, underscoring the profitability of the process for producing filler material from mining waste, which has the potential to generate substantial profits in the long run.

Peganum Harmala L. plant as green non-toxic adsorbent for iron removal from water

The present work focuses on examining the batch removal of Fe (III) from water using powdered Peganum Harmala seeds, characterized as FT-IR. In this work, several parameters are measured, including contact time, pH, Fe (III) concentration, reaction temperature effect, and adsorbent dose effect. Fe (III) adsorption was assessed using a UV-vis spectrophotometer at a wavelength of 620 nm. The findings demonstrated a positive correlation between the dosage of adsorbent and Fe (III) ions removal, with an increase in the adsorbent dose corresponding to higher elimination of Fe (III) ions. Therefore, the Langmuir isotherm model yielded more accurate equilibrium data compared to the Frendulich model. The kinetic data were mostly analyzed using a pseudo-second-order model rather than a pseudo-first-order model. Thermodynamic parameters, including enthalpy (ΔH◦), entropy (ΔS◦), and free energy (ΔG◦), were calculated. The adsorption process was found to be exothermic. Overall, Peganum Harmala was a favorable adsorbent for removing Fe (III) from aqueous solutions.

Mechanistic Constraints on the Drivers of Southern Ocean Meridional Iron Distributions Between Tasmania and Antarctica

AbstractWhile modeling efforts have furthered our understanding of marine iron biogeochemistry and its influence on carbon sequestration, observations of dissolved iron (dFe) and its relationship to physical, chemical and biological processes in the ocean are needed to both validate and inform model parameterization. Where iron comes from, how it is transported and recycled, and where iron removal takes place are critical mechanisms that need to be understood to assess the relationship between iron availability and primary production. To this end, hydrographic and trace metal observations across the GO‐SHIP section SR3, south of Tasmania, Australia, have been analyzed in tandem with the novel application of an optimum multiparameter analysis. From the trace‐metal distribution south of Australia, key differences in the drivers of dFe between oceanographic zones of the Southern Ocean were identified. In the subtropical zone, sources of dFe were attributed to waters advected off the continental shelf, and to recirculated modified mode and intermediate water‐masses of the Tasman Outflow. In the subantarctic zone, the seasonal replenishment of dFe in Antarctic surface and mode waters appears to be sustained by iron recycling in the underlying mode and intermediate waters. In the southern zone, the dFe distribution is likely driven by dissolution and scavenging by high concentrations of particles along the Antarctic continental shelf and slope entrained in high salinity shelf water. This approach to trace metal analysis may prove useful in future transects for identifying key mechanisms driving marine dissolved trace metal distributions.

Selective recovery of rare earth elements by smelting of magnets

Rare earth elements (REEs) play a crucial role in many technologies from daily appliances in cell phones to more advanced wind turbines and electric cars. Permanent magnets account for a quarter of total global REEs production and have high recycling value. In this study, smelting process was used to selectively oxidize REEs in the permanent magnets by adding Fe2O3. This separates REEs into a slag phase from an iron-rich metallic phase. B2O3 was also added to the system as a flux to lower the slag melting temperature. This minimizes REEs loss to the metallic phase and allows a more efficient phase separation. The effect of flux and oxidizing agent addition was investigated on both regular and cerium-rich NdFeB (NdCeFeB) magnets. At 1350 °C and for 1 h, the slag phase was successfully separated from the metallic phase with the addition of 0.8 stoichiometric amount of Fe2O3 and 40 wt% of B2O3. Scanning electron microscopy–energy dispersive X-ray spectroscopy (SEM-EDX) analysis reveals that REEs in the magnet do not migrate to the metal phase while the REE-rich slag phase contains almost no iron. After the selective removal of iron into the metallic phase, REEs are recovered from the slag phase through an acid leaching process allowing >99% of REEs recovery. Boron in the magnet can also be recovered as useful boric acid by evaporation and crystallisation technique. The proposed process in this study is reagent and energy-efficient with almost complete valorisation of both NdCeFeB and NdFeB magnets.

Optimized modes of iron removal from highly concentrated chloride solutions amid transition to nickel electrowinning process

Optimized modes of iron removal from highly concentrated chloride solutions amid transition to nickel electrowinning process

Pancreatic iron in pediatric transfusion-dependent beta-thalassemia patients: A longitudinal MRI study.

In pediatric transfusion-dependent thalassemia (TDT) patients, we evaluated the prevalence, pattern, and clinical associations of pancreatic siderosis and the changes in pancreatic iron levels and their association with baseline and changes in total body iron balance. We considered 86 pediatric TDT patients consecutively enrolled in the Extension-Myocardial Iron Overload in Thalassemia Network. Iron overload (IO) was quantified by R2* magnetic resonance imaging (MRI). Sixty-three (73%) patients had pancreatic IO (R2*>38Hz). Global pancreas R2* values were significantly correlated with mean serum ferritin levels, MRI liver iron concentration (LIC) values, and global heart R2* values. Global pancreas R2* values were significantly higher in patients with altered versus normal glucose metabolism. Thirty-one patients also performed the follow-up MRI at 18±3months. Higher pancreatic R2* values were detected at the follow-up, but the difference versus the baseline MRI was not significant. The 20% of patients with baseline pancreatic IO showed no pancreatic IO at the follow-up. The 46% of patients without baseline pancreatic IO developed pancreatic siderosis. The changes in global pancreas R2* between the two MRIs were not correlated with baseline serum ferritin levels, baseline, final, and changes in MRI LIC values, or baseline pancreatic iron levels. In children with TDT, pancreatic siderosis is a frequent finding associated with hepatic siderosis and represents a risk factor for myocardial siderosis and alterations of glucose metabolism. Iron removal from the pancreas is exceptionally challenging and independent from hepatic iron status.

Iron deficiency suppresses the Fenton reaction and boosts photosynthetic H2 production in bisulfite-treated Chlamydomonas cells

Adding bisulfite is a significant strategy to enhance H2 photoproduction, but it adversely affects photosystem II (PSII) activity in microalgae, consequently limiting H2 production. Nevertheless, the exact mechanism through which bisulfite disrupts PSII remains unclear. Here, the addition of NaHSO3 to Chlamydomonas reinhardtii cultures suppresses growth by inducing iron poisoning through the Fenton reaction, driven by reduced iron demand and the resultant accumulation of iron. Consequently, the removal of iron from C. reinhardtii cultures eliminates the iron poisoning triggered by the Fenton reaction. This, in turn, mitigates PSII impairment and leads to a significant increase in photosynthetic H2 production in C. reinhardtii cells. Collectively, these discoveries unveil the precise mechanism by which bisulfite disrupts PSII, opening up a new avenue for substantially enhancing green hydrogen production from microalgae through the bisulfite addition strategy.