Search

Iron is one of the most abundant elements in the Universe and Earth's surfaces, and undergoes a redox change of approximately 0.77 mV in changing between its +2 and +3 states. Many contemporary terrestrial organisms are deeply connected to inorganic geochemistry via exploitation of this redox change, and iron redox reactions and catalysis are known to cause significant changes in the course of complex abiotic reactions. These observations point to the question of whether iron may have steered prebiotic chemistry during the emergence of life. Using kinetically naive in silico reaction modeling we explored the potential effects of iron ions on complex reaction networks of prebiotic interest, namely the formose reaction, the complexifying degradation reaction of pyruvic acid in water, glucose degradation, and the Maillard reaction. We find that iron ions produce significant changes in the connectivity of various known diversity-generating reaction networks of proposed prebiotic significance, generally significantly diversifying novel molecular products by ~20%, but also adding the potential for kinetic effects that could allow iron to steer prebiotic chemistry in marked ways. [ABSTRACT FROM AUTHOR]

Iron (Fe) plaque, which forms on the surface of rice roots, plays a crucial role in immobilizing heavy metal(loids), thus reducing their accumulation in rice plants. However, the principal factors influencing Fe plaque formation and its adsorption capacity for heavy metal(loid)s throughout the rice plant's lifecycle remain poorly understood. Thus, this study investigated the dynamics of Fe plaque formation and its ability to adsorb cadmium (Cd) and arsenic (As) across different growth stages, aiming to identify the key drivers behind these processes. The findings reveal that the rate of radial oxygen loss (ROL) and the abundance of plaque-associated microbes are the primary drivers of Fe plaque formation, with their relative importance ranging from 1.4% to 81%. Similarly, the adsorption of As by Fe plaque is principally determined by the rate of ROL and the quantity of Fe plaque, with subsequent effects from the total Fe in rhizospheric soil, arsenate-reducing bacteria, and organic matter-degrading bacteria. The relative importance of these factors ranges from 6.0% to 11.7%. By contrast, the adsorption of Cd onto Fe plaque is primarily affected by competition for adsorption sites with ammonium in soils and the presence of organic matter-degrading bacteria, contributing 25.5% and 23.5% to the adsorption process, respectively. These findings provide significant insights into the development of Fe plaque and its absorption of heavy metal(loid)s throughout the lifecycle of rice plants., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The recovery of rare earth elements (REEs) is a major issue based on environmental governance and sustainable resource utilization. In this study, we developed a novel hydrogel material (Fe/Mn@ALG) by anchoring Fe/Mn NPs on alginate spheres, where Fe/Mn NPs were in-situ synthesized using Euphorbia cochinchensi leaf extract as reduced and protection agents. The Fe/Mn@ALG was applied directly to real mine wastewater, generating efficient and selective recovery of REEs with the coexistence of numerous competing metal ions. As results have shown, Fe/Mn@ALG was a useful adsorbent for REEs with an adsorption efficiency 78.62 % achieved, which was also confirmed by distribution coefficients (K d ), up to 2451.66 mL·g -1 . Furthermore, Fe/Mn@ALG exhibited preferential response to REEs over other metal ions with the separation factor (SF) being up to 240. This great adsorption performance and selectivity toward REEs were attributed to its specific surface area, oxygen-rich functional groups and negatively charged surface in acid wastewater. Furthermore, REEs could be greatly desorbed from Fe/Mn@ALG with output concentration being three times higher than the initial concentration. Additionally, Fe/Mn@ALG maintained its good adsorption performance with efficiency reaching 72.24 % after five reuses. Overall, Fe/Mn@ALG can be considered as a promising candidate for wastewater remediation and sustainable management of resources., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Chemiluminescence (CL) analysis is a promising analytical method with advantages including easy operation, high sensitivity and simple instrument. However, the single CL mode usually suffered from poor stability and reproducibility as a result of the flash-type nature of luminescent molecules, leading to false positive or negative results in practical applications. Dual-mode detection is an advanced sensing methodology that identifies analytes through independent output signals. This approach has the ability to circumvent the inherent constraints of individual sensing modes while integrating their respective strengths, thereby yielding a synergistic enhancement in the detection system., Results: Herein, a chemiluminescence-fluorescence (FL) dual-mode analysis and imaging system is designed by constructing an atomically Fe(Ⅲ) anchored PCN-224 peroxidase-mimicking nanozyme (PCN-224/Fe(Ⅲ)) and achieve an ultrasensitive detection of Uric Acid (UA). The multifunctional PCN-224/Fe(Ⅲ) serves as a high-efficiency co-reaction promoter in the generation of reactive oxygen species (ROS) in both the CL and FL system, while also demonstrating exceptional capabilities as fluorescent nanoprobes. Ultimately, a smartphone-adopted CL imaging device was developed to achieve a visual CL detection through the design of portable paper-based chips. Besides, with the assistance of the TMB-mediated fluorescence energy resonance transfer, the fluorescent PCN-224/Fe(Ⅲ) nanoprobes exhibited good fluorescence detection performance for UA. The limit of detection was achieved as low as 2.45 × 10 -10  M and 1.99 × 10 -9  M in the CL and FL mode, respectively., Significance: This study engineered an atomically Fe(Ⅲ)- MOF-based multifunctional nanozyme and developed an innovative approach for creating CL-FL dual-mode analysis and imaging detection for UA. The proposed CL-FL dual-mode detection system not only provided a portable and sensitive method for UA detection but also offered valuable insights into the mechanism of the co-reaction promoter enhanced CL and FL analysis., Competing Interests: Declaration of competing interest The authors declare no competing financial interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

NH 4 + is an ion with versatile potential; however, the release of wastewater containing this component, regardless of its high or low concentration, causes severe eutrophication in aquatic systems and contaminates numerous manufacturing processes. Thus, this study developed a sustainable method that can simultaneously remove, recover NH 4 + , polish water, oxidize organic matter, and yet release a material that can still be used as fertilizer. Regarding NH 4 + removal, FeP400 rapidly exhibited an exceptional NH 4 + uptake capacity (343.5 mg g -1 ) within 8 min, even in dairy processing wastewater with high NH 4 + concentrations and diverse co-existing components. FeP400 could oxidize organic compounds spontaneously to remove TOC, indirectly enhancing its NH 4 + uptake up to 33.5 % through charge balance mechanisms. The adsorption process involved both chemical (i.e., double-salt precipitation) and physical mechanisms (i.e., H-bonding and electrostatic interaction), as confirmed by thermodynamics, FT-IR, and XPS analyses. Regarding recovery, FeP400 can be reused for over 10 cycles with high removal (81 %) and NH 4 + recovery (88 %), a significant improvement over conventional options. FeP400 also performed efficiently under flowing conditions using low-range NH 4 + and TOC samples over 10 cycles, polishing not only 34.1 L of water with undetected NH 4 + , neutral pH, and extremely low TOC but also effectively recovering the NH 4 + uptake at an economical cost. Lastly, its environmentally friendly nature, which contains essential nutrients for plant growth, further enhances its recyclability after release. Thus, FeP400 is believed to offer a transformative, sustainable, and highly efficacious solution to the NH 4 + contamination and critical ultrapure water issues that industries urgently address., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The widespread presence of iron (Fe) particles and natural organic matter (NOM) in drinking water distribution systems (DWDS) can significantly affect tap water quality, contributing to aesthetic issues and potentially generating harmful disinfection byproducts (DBPs). This study revealed that Fe particles, when combined with humic acid (HA), substantially increased DBP formation during chlorination. Fe particles (particularly preformed Fe particles) significantly increased haloacetic acid (HAA) formation by activating the persistent free radicals (PFRs) in the HA. Compared with the control system without Fe particles, greater than 2 times of HAA increase were observed for the system with Fe pariticles. PFRs accumulated on Fe particle surface could generate hydroxyl radicals, facilitating the decomposition of HA into smaller molecules, which were more reactive with chlorine disinfectants, thus elevated the DBP formation including both known and unknown N-DBPs and Cl-DBPs. The DBP promotion effect of in-situ formed Fe particles was much less than that of preformed Fe particles although both in-situ formed and preformed Fe particles could accumulate PFRs from HA. In-situ formed particles primarily accumulated carbon-centered PFRs, while preformed particles accumulated oxygen-centered PFRs. To mitigate the Fe particle induced water quality risks, it is crucial to control iron pipe corrosion and iron release in DWDS. In addtion, the optimization of treatment processes such as coagulation and filtration to more completely remove NOM and Fe particles could help minimize the DBP formation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

As an electrochemical advanced oxidation process, the electro-Fenton (EF) process has gained significant importance in the treatment of wastewater and persistent organic pollutants in recent years. As recently reported in a bibliometric analysis, the number of scientific publications on EF have increased exponentially since 2002, reaching nearly 500 articles published in 2022 (Deng et al., 2022). The influence of the main operating parameters has been thoroughly investigated for optimization purposes, such as type of electrode materials, reactor design, current density, and type and concentration of catalyst. Even though most of the studies have been conducted at a laboratory scale, focusing on fundamental aspects and their applications to degrade specific pollutants and treat real wastewater, important large-scale attempts have also been made. This review presents and discusses the most recent advances of the EF process with special emphasis on the aspects more closely related to future implementations at the large scale, such as applications to treat real effluents (industrial and municipal wastewaters) and soil remediation, development of large-scale reactors, costs and effectiveness evaluation, and life cycle assessment. Opportunities and perspectives related to the heterogeneous EF process for real applications are also discussed. This review article aims to be a critical and exhaustive overview of the most recent developments for large-scale applications, which seeks to arouse the interest of a large scientific community and boost the development of EF systems in real environments., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Anthropogenic enrichment of phosphorus (P) in water environment can cause eutrophication, harmful algal blooms, and water quality deterioration. Adsorbents are often used for the removal and recovery of P from water, however, P is highly susceptible to re-release in anoxic benthic environments. As a response, this study prepared oxygen-carrying iron-rich biochar (O-Fe-BC) as an effective oxygen micro-nanobubble carrier (Q = 8.7024 cm³/g STP at 1.5 MPa) and P adsorbent (q m = 16.7097 mg P/g, q 0.1 = 3.1974 mg P/g). Over the 90-day experimental period with O-Fe-BC, dissolved oxygen (DO) levels in the overlying water could maintain at ∼4 mg/L (peaking at ∼9.5 mg/L), and total phosphorus (TP) and soluble reactive phosphorus (SRP) levels decreased by over 96 %. The higher inorganic phosphorus content in the surface sediment-biochar mixture, along with the lower labile P and Fe concentration in the sediment pore water in the O-Fe-BC group compared to other groups, suggested the enhanced P immobilization. Further mechanism exploration revealed the combined roles of adsorption and microbial response, in which O-Fe-BC achieved efficient phosphate adsorption primarily through inner-sphere complexation via ligand exchange and keystone taxa (particularly Candidatus Electronema) played a crucial role in driving water chemistry divergence. Specially, these cable bacteria could provide large pools of Fe oxides in the surface sediment, binding with P to prevent its release, as supported by significant correlations between Ca. Electronema abundance and oxidation-reduction potential (ORP), TP, SRP, and sediment Fe-P variations. Additionally, a pot experiment with mung bean seedlings showed that the recovered O-Fe-BC significantly promoted the seed germination and growth, indicating its potential as a novel material for removing and recovering P from eutrophic waters. Taken together, our work provided a promising strategy for sustainable anoxia and P pollution mitigation, and also highlighted the indispensable roles of inner-sphere adsorption in P recovery and microbial keystone taxa in P cycling regulation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Recently, great efforts have been made to advance the pilot-scale and engineering-scale applications of Fenton-like processes using various nano-metal catalysts (including nanosized metal-based catalysts, smaller nanocluster catalysts, and single-atom catalysts, etc.). This step is essential to facilitate the practical applications of advanced oxidation processes (AOPs) for these highly active nano-metal catalysts. Before large-scale implementation, these nano-metal catalysts must be converted into the effective catalyst modules (such as catalytic membranes, fluidized beds, or polypropylene sphere suspension systems), as it is not feasible to use suspended powder catalysts for large-scale treatment. Therefore, the pilot-scale and engineering applications of nano-metal catalysts in Fenton-like systems in recent years is exciting. In addition, the combination of life cycle assessment (LCA) and techno-economic analysis (TEA) can provide a useful support tool for engineering scale Fenton-like applications. This paper summarizes the designs and fabrications of various advanced modules based on nano-metal catalysts, analyzes the advantages and disadvantages of these catalytic modules, and further discusses their Fenton-like pilot scale or engineering applications. Concepts of future Fenton-like engineering applications of nano-metal catalysts were also discussed. In addition, current challenges and future expectations in pilot-scale or engineering applications are assessed in conjunction with LCA and TEA. These challenges require further technological advances to enable larger scale engineering applications in the future. The aim of these efforts is to increase the potential of nanoscale AOPs for practical wastewater treatment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

This study investigated a sustainable approach through dielectric barrier discharge (DBD) enhanced Fenton technology coupling nanofiltration (NF) process for landfill leachate treatment. The DBD/Fe(II)/H 2 O 2 system exhibited significant synergistic effects, removing 55.07 % of TOC and 53.79 % of UV 254 within 60 min, respectively. Additionally, the DBD/Fe(II)/H 2 O 2 system demonstrated exceptional performance in removing fluorescent substances and large molecular organic compounds, thereby reducing the formation of cake layer on the nanofiltration membrane. Moreover, membrane flux increased by 2.34 times, with reversible and irreversible resistances decreasing by 75.79 % and 81.55 %, respectively. Quenching experiments revealed ·OH as the primary active species for perfluorooctanoic acid (PFOA) degradation in the DBD/Fe(II)/H 2 O 2 process. The degradation pathway of PFOA was also elucidated via capillary electrophoresis-quadrupole time-of-flight mass spectrometry analysis. Correlation analysis indicated that TOC and EEM were the primary fouling factors. Lastly, through an assessment of energy consumption, economic costs, and carbon dioxide emissions, the advantages and practical application potential of the DBD/Fe(II)/H 2 O 2 system were demonstrated. In summary, the DBD/Fe(II)/H 2 O 2 system emerges as a feasible strategy for NF pretreatment, holding immense potential for treating landfill leachate., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

This paper examines the acid leaching efficiencies of Fe and P from vivianite slurry (VS, Fe 3 (PO 4 ) 2 ·8H 2 O), which is magnetically separated from anaerobic digested sludge, and elaborates on Fe and P reuse routes. The characteristics and dissolution behavior of raw VS in hydrochloric, sulfuric, phosphoric, oxalic, and citric acids are investigated. Results reveal that the primary impurities in VS are organic matter, other phosphate compounds, and Mg present in the vivianite crystal structure. Hydrochloric and sulfuric acids could effectively extract P (90%) from VS at an optimal hydrogen-to-phosphorus (H⁺/P) ratio of 2.5, compared with sewage sludge ash (SSA) that normally needs an H⁺/P ratio greater than 3. Hence, VS can be employed as an alternative P resource following a similar recovery route used with SSA. However, in comparison to SSA, VS use can decrease acid consumption in P extraction and the requirement for the extensive purification of cationic impurities. Furthermore, oxalic acid effectively facilitates the separation of P and Fe in VS by precipitating Fe as insoluble ferrous oxalate in acidic conditions, leading to a high Fe recovery rate of 95%. The recovery and reuse of Fe through the oxalic acid route further improves the feasibility of VS as an alternate resource., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Yudong Zhao, Outi Grönfors, Terhi Suopajärvi, Tero Luukkonen, Henrikki Liimatainen have patent METHOD FOR SEPARATING IRON AND PHOSPHORUS FROM AN IRON PHOSPHATE-BASED MATERIAL OBTAINABLE FROM A WASTE WATER TREATMENT PROCESS pending to Kemira Oyj. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Highly hydrophilic extracellular polymeric substance (EPS) with gel-like structure seriously plagues the development of sludge deep dewatering. Oxysulfur radicals-based oxidation driven by iron-bearing mineral proposes a promising strategy for effective EPS decomposition. However, the transformation and involved interaction mechanisms of aromatic proteins are still controversial due to the complex EPS structure. Herein, sulfite mediated siderite (denoted as Fe(II)/S(IV)) was developed for targeted transformation aromatic amino acids in EPS oxidation to strengthen sludge solid-liquid separation. The enhanced sludge dewaterability were benefited from the Fe(II)/S(IV) bonded interaction assisted by Fe 3+ /Fe 2+ as redox interface that facilitating the release of intracellular bound water via diminish the hydrophily and bind strength with solid protons. The amide region nitrogen of aromatic amino acids (especially tyrosine and tryptophan) originating from EPS presented looser structure and lower spatial site resistance, which were attributed to the exposure of hydrophobic sites in amino groups after Fe(II)/S(IV) treatment. Furthermore, the effective decline of aromatic amino acids in inner layer-EPS (loosely bound EPS and tightly bound EPS) was directed from Fe-N targeted interaction by triggering a series of sulfate-based radical chain reactions. The good correlation between electron transfer amount (R 2 = 0.926) and Fe-N (R 2 = 0.925) with bonding interaction demonstrated that the complexation of aromatic amino acids with Fe sites on siderite/sulfite via Fe-N bonds, accounting for efficient sludge solid-liquid separation. This study deepens the understanding of sludge organic matter targeted transformation and provides a tactic for iron-based conditioning of sludge., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Ammonium oxidation coupled with Fe(III) reduction, known as Feammox, and nitrate-dependent ferrous oxidation (NDFO) are two processes that can be synergistically achieved through the Fe(III)/Fe(II) cycle. This integrated approach enables the simultaneous removal of ammonia nitrogen (NH 4 + -N) and nitrate nitrogen (NO 3 - -N) from wastewater, representing a novel method for complete nitrogen removal. This study presents a systematic and exhaustive examination of the Feammox-NDFO coupled process. An initial thorough exploration of the underlying mechanisms behind the coupling process is conducted, highlighting how the Fe(III)/Fe(II) cycle enables the concurrent occurrence of these reactions. Further, the functional microorganisms associated with and playing a crucial role in the Feammox-NDFO process are summarized. Next, the key influencing factors that govern the efficiency of the Feammox-NDFO process are explored. These include parameters such as pH, temperature, carbon source, iron source, nitrogen source, and various electron shuttles that may mediate electron transfer. Understanding the impact of these factors is essential for optimizing the process. The most recent trends and endeavors on the Feammox-NDFO coupling technology in wastewater treatment applications are also examined. This includes examining both laboratory-scale studies and field trials, highlighting their successes and challenges. Finally, an outlook is presented regarding the future advancement of the Feammox-NDFO technology. Areas of improvement and novel strategies that could further enhance the efficiency of simultaneous nitrogen removal from the iron cycle are discussed. In summary, this study aspires to offer a thorough comprehension of the Feammox-NDFO coupled process, with a focus on its mechanisms, influencing factors, applications, and prospects. It is anticipated to yield invaluable insights for the advancement of process optimization, thus sparking fresh ideas and strategies aimed at accomplishing the thorough elimination of nitrogen from wastewater via the iron cycle., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Aerospace magnetic material scraps are abundant in cobalt and nickel. Sulfuric acid leaching process is an efficient method for extracting them. But it is a non-selective process, a significant amount of iron dissolves in the solution. This study focuses on the selective removal of iron from this solution using the jarosite process. E h -pH diagram of K-S-Fe-H 2 O system was established. Based on thermodynamic analysis, H 2 O 2 is used to oxidize Fe 2+ into Fe 3+ , achieving efficient and selective removal of iron from the solution containing cobalt and nickel. The optimal conditions are as follows: temperature 95°C, K 2 SO 4 dosage coefficient 1.5, seed dosage 10 g/L, time 90 min, pH 1.76, and endpoint pH controlled at approximately 3. Under these conditions, the iron removal efficiency is above 99%, while the loss ratios of cobalt and nickel are below 2%. The product is characterized by XRD and SEM-EDS. Results indicate that the product is jarosite ((K,H 3 O)Fe 3 (SO 4 ) 2 (OH) 6 ), exhibiting an ellipsoid structure with the mean particle size in the range of 0.2-5.0 μm. Temperature, pH value and seed dosage significantly affect reaction rate, particle size and crystallinity, and K 2 SO 4 dosage mainly affects reaction rate and the morphology of jarosite. The jarosite crystallization kinetics can be described by the Avrami equation, with an Avrami index (n) of approximately 2.5 and the apparent activation energy of 42.68 kJ/mol., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Metal-organic gels (MOGs) are a type of metal-organic colloid material with a large specific surface area, loose porous structure, and open metal active sites. In this work, FeNi-MOGs were synthesized by the simple one-step static method, using Fe(III) and Ni(II) as the central metal ions and terephthalic acid as the organic ligand. The prepared FeNi-MOGs could effectively catalyze the chemiluminescence of luminol without the involvement of H 2 O 2 , which exhibited good catalytic activity. Then, the multifunctional detected platform was constructed for the detection of GSH and Hg 2+ , based on the antioxidant capacity of GSH, and the strong affinity between mercury ion (Hg 2+ ) and GSH which inactivated the antioxidant capacity of GSH. The experimental limits of detection (LOD) for GSH and Hg 2+ were 76 nM and 210 nM, and the detection ranges were 2-100 μM and 8-4000 μM, respectively. The as-proposed sensor had good performance in both detection limit and detection range of GSH and Hg 2+ , which fully met the needs of daily life. Surprisingly, the sensor had low detection limits and an extremely wide detection range for Hg 2+ , spanning five orders of magnitude. Furthermore, the detection of mercury ions in actual lake water and GSH in human serum showed good results, with recovery rates ranging from 90.10 % to 105.37 %, which proved that the method was accurate and reliable. The as-proposed sensor had great potential as the platform for GSH and Hg 2+ detection applications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

An effective electrochemical sensor was developed to detect and determine of the As(III) by modifying the carbon paste electrode (CPE) with graphitic carbon nitride decorated with iron-based metal-organic frameworks (Fe-MOF/g-C 3 N 5 ). The differential pulse anodic stripping voltammetry (DPASV) method was used to analyze As(III) ions in a phosphate buffer solution (0.10 M, pH = 5). Fe-MOF/g-C 3 N 5 /CPE showed high sensitivity (4.24 μA μg -1  L), satisfactory linear range (0.50 μg L -1 -5.00 μg L -1 and 5.00 μg L -1 -30.00 μg L -1 ), and low detection limit (LOD, 0.013 μg L -1 ). The prepared sensor was showed an excellent repeatability and selectivity, and successfully used for determination of the As(III) ion in ambient waters and apple juice samples., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Mostafa najafi reports was provided by Imam Hossein University. Mostafa Najafi reports a relationship with Imam Hossein university that includes: board membership. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

The performance of Electro-Fenton (EF) cathode materials is primarily assessed by H 2 O 2 yield and Fe 3+ reduction efficiency. This study explores the impact of pore structure in chitin-based porous carbon on EF cathode effectiveness. We fabricated mesoporous carbon (CPC-700-2) and microporous carbon (ZPC-700-3) using template and activation methods, retaining nitrogen from the precursors. CPC-700-2, with mesopores (3-5 nm), enhanced O 2 diffusion and oxygen reduction, producing up to 778 mg/L of H 2 O 2 in 90 min. ZPC-700-3, with a specific surface area of 1059.83 m 2 /g, facilitated electron transport and ion diffusion, achieving a Fe 2+ /Fe 3+ conversion rate of 79.9%. EF systems employing CPC-700-2 or ZPC-700-3 as the cathode exhibited superior degradation performance, achieving 99% degradation of Rhodamine B, efficient degradation, and noticeable decolorization. This study provides a reference for the preparation of functionalized carbon cathode materials for efficient H 2 O 2 production and effective Fe 3+ reduction in EF systems., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The resource utilization of natural pyrite not only reduces secondary pollution but also brings certain environmental benefits. However, the green and efficient use of pyrite presents certain challenges. In this study, a novel electro-Fenton (EF) system was constructed utilizing copper modified graphite felt (GF/Cu) as cathode and natural pyrite (com-FeS 2 ) as catalyst. The results demonstrated that the system exhibited a remarkable stability over an extensive pH range (3.0-10.0) and remained effective even under adverse environmental conditions, such as high salinity or elevated antibiotic concentration. After optimizing the reaction conditions, 0.2 mM sulfamerazine (SMZ) was almost completely degraded within 1.5 h. The results highlighted the catalytic role of Fe(II) on the com-FeS 2 surface. Combined with quenching experiments and quantitative analysis of reactive oxygen species (ROS), the removal of SMZ was primarily attributed to the generation of •OH, ordered by 1 O 2  > •O 2 -  > •OH ads , a possible degradation pathway was proposed by HR-LC-MS. The biological toxicity after the reaction was detected, and the introduction of polyvinylpyrrolidone (PVP) was beneficial to reduce the biological toxicity of iron dissolution. This work provides new insights into the green and efficient resource utilization of natural pyrite and significantly expands the pH applicability range of the Fenton process, demonstrating the large-scale industrial application potential of pyrite., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Amino acids are present in all known life, so identifying the environmental conditions under which they can be synthesized constrains where life on Earth might have formed and where life might be found on other planetary bodies. All known abiotic amino acid syntheses require ammonia, which is only produced in reducing and neutral atmospheres. Here, we demonstrate that the Fe-bearing hydroxide mineral ferroan brucite [Fe 0.33 ,Mg 0.67 (OH) 2 ] can mediate the reaction of nitrate and glyoxylate to form glycine, the simplest amino acid used in life. Up to 97% of this glycine was detected only after acid digestion of the mineral, demonstrating that it had been strongly partitioned to the mineral. The dicarboxylic amino acid 3-hydroxy aspartate was also detected, which suggests that reactants underwent a mechanism that simultaneously produced mono- and dicarboxylic amino acids. Nitrate can be produced in both neutral and oxidizing atmospheres, so reductive amination of nitrate and glyoxylate on a ferroan brucite surface expands origins of life scenarios. First, it expands the environmental conditions in which life's precursors could form to include oxidizing atmospheres. Second, it demonstrates the ability of ferroan brucite, an abundant, secondary mineral in serpentinizing systems where olivine is partly hydrated, to mediate reductive amination. Finally, the results demonstrate the need to consider mineral-bound products when analyzing samples for abiotic amino acid synthesis., Competing Interests: Competing interests statement:The authors declare no competing interest.

Iron-bearing smectite clay minerals can act as electron sources and sinks in the environment. Previous studies using mediated electrochemical analyses to determine the reduction potential ( E H ) values of smectites observed that the relationship between the structural Fe 2+ (s) /Fe Total ratio in the smectite and E H varied based on the redox history of the smectite. We hypothesize that this behavior, referred to as redox hysteresis, results from the smectite particles not equilibrating with the applied E H over the course of the experiment (∼30 min). To test this hypothesis, we developed a model incorporating interfacial electron transfer kinetics and charge redistribution within the particle to simulate the mediated electrochemical experiments from previous studies. The simulated redox curves accurately matched the previously reported experimental redox curves of the smectite SWa-1, demonstrating that longer equilibration periods led to a decrease in redox hysteresis. We validated this experimentally by measuring the redox curve of SWa-1 after an equilibration period of at least 12 h. Furthermore, we extended the simulations to three other smectites (NAu-1, NAu-2, and SWy-2) and extracted their respective thermodynamic and kinetic parameters. This work offers a framework for interpreting and modeling redox reactions on clay surfaces, along with key parameters for four commonly studied smectites.

Existing strategies to investigate the antitumor effects of artemisinin and its derivatives (ART) are inadequate. Both free Fe(II) and heme in mitochondria have been proposed to be ART activators. However, the two impact factors have been considered separately or have not been thoroughly investigated. Here, the designed ART-based novel nanosystem with transferrin-modified hollow mesoporous silica nanoparticles as drug-delivery carriers is loaded with a functional artemisinin derivative (Cou-DHA), glucose oxidase, and perfluoropentane inside the cavity, which can enhance synergistic Fe(II)-ART-mediated chemodynamic therapy (CDT). Under the action of H 2 O 2 generated by starvation therapy, the Fenton reaction occurs with Fe(III) in transferrin converted into free Fe(II). Remarkably, this report is the first to provide Fe(II) to ART actively and efficiently by combining starvation therapy and Fenton reaction-based CDT. Importantly, mitochondria-targeted Cou-DHA delivers ART into the mitochondria to sensitize the anticancer effects of ART with the supplied Fe(II) to realize Fe(II)-ART-mediated CDT. The ART-based novel nanosystem developed in our work thus has great potential for exploitation in advanced cancer therapies.

Glomalin-related soil protein (GRSP) has demonstrated significant potential for water purification and remediation of heavy metals in soils; however, its redox reactivity for As(III) sequestration and the corresponding redox-active component are still poorly understood. This study investigated the photochemical properties of GRSP and its mechanism of oxidation/adsorption of As(III). The results showed that UV irradiation triggered electron transfer and the production of reactive oxygen species (ROS) in GRSP, thereby facilitating As(III) oxidation with promotion rates ranging from 43.34 % to 111.1 %. The oxidation of As(III) occurred both on the GRSP photoforming holes and in the ROS reaction from the oxygen reduction products of the photoforming electrons. OH• and H 2 O 2 played an important role in the oxidation of As(III) by GRSP, especially under alkaline conditions. Moreover, the presence of Fe(III) in GRSP facilitated the formation of OH• and its the oxidation capacity towards As(III). The binding of As(III) to the -COOH, -OH, and -FeO groups on the GRSP surface occurred through surface complexation. Overall, these findings provided new insights into the roles of the redox-active moieties and Fe(III) on GRSP in the promoted oxidation of As(III), which would help to deepen our understanding of the migration and transformation of As(III) in soils., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The extensive use of antibiotics has created an urgent need to address antibiotic wastewater treatment, posing significant challenges for environmental protection and public health. Recent advances in the efficacy and mechanisms of conductive materials (CMs) for enhancing the anaerobic biological treatment of antibiotic pharmaceutical wastewater are reviewed. For the first time, the focus is on the various application forms of iron-based and carbon-based CMs in strengthening the anaerobic methanogenic system. This includes the use of single CMs such as zero-valent iron (ZVI), magnetite, biochar (BC), activated carbon (AC), and graphene (GP), as well as iron-based and carbon-based composite CMs with diverse structures. These structures include mixed, surface-loaded, and core-shell combinations, reflecting the development of CMs. Iron-based and carbon-based CMs promote the rapid removal of antibiotics through adsorption and enhanced biodegradation. They also mitigate the inhibitory effects of toxic pollutants on microbial activity and reduce the expression of antibiotic resistance genes (ARGs). Additionally, as effective electron carriers, these CMs enrich microorganisms with direct interspecies electron transfer (DIET) functions, accelerate interspecies electron transfer, and facilitate the conversion of organic matter into methane. Finally, this review proposes the use of advanced molecular detection technologies to clarify microbial ecology and metabolic mechanisms, along with microscopic characterization techniques for the modification of CMs. These methods can provide more direct evidence to analyze the mechanisms underlying the cooperative anaerobic treatment of refractory organic wastewater by CMs and microorganisms., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Ultrafiltration (UF) is widely employed for harmful algae rejection, whereas severe membrane fouling hampers its long-term operation. Herein, calcium peroxide (CaO 2 ) and ferrate (Fe(VI)) were innovatively coupled for low-damage removal of algal contaminants and fouling control in the UF process. As a result, the terminal J/J 0 increased from 0.13 to 0.66, with R r and R ir respectively decreased by 96.74 % and 48.47 %. The cake layer filtration was significantly postponed, and pore blocking was reduced. The ζ-potential of algal foulants was weakened from -34.4 mV to -18.7 mV, and algal cells of 86.15 % were removed with flocs of 300 µm generated. The cell integrity was better remained in comparison to the Fe(VI) treatment, and Fe(IV)/Fe(V) was verified to be the dominant reactive species. The membrane fouling alleviation mechanisms could be attributed to the reduction of the fouling loads and the changes in the interfacial free energies. A membrane fouling prediction model was built based on a long short-term memory deep learning network, which predicted that the filtration volume at J/J 0 = 0.2 increased from 288 to 1400 mL. The results provide a new routine for controlling algal membrane fouling from the perspective of promoting the generation of Fe(IV)/Fe(V) intermediates., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Iron-sulfur cluster conversion and nitrosyl modification are involved in regulating their functions and play critical roles in signaling for biological systems. Hereby, the photo-induced dynamic process of (Me 4 N) 2 [Fe 2 S 2 (NO) 4 ] was monitored using time-resolved electron paramagnetic resonance (EPR) spectra, MS spectra and cellular imaging methods. Photo-irradiation and the solvent affect the reaction rates and products. Spectroscopic and kinetic studies have shown that the process involves at least three intermediates: spin-trapped NO free radical species with a g av at 2.040, and two other iron nitrosyl species, dinitrosyl iron units (DNICs) and mononitrosyl iron units (MNICs) with g av values at 2.031 and 2.024, respectively. Moreover, the [Fe 2 S 2 (NO) 4 ] 2- cluster could bind with ferritin and decompose gradually, and a binding state of dinitrosyl iron coordinated with Cys102 of the recombinant human heavy chain ferritin (rHuHF) was finally formed. This study provides insight into the photodynamic mechanism of nitrosyl iron - sulfur clusters to improve the understanding of physiological activity., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

For the sustainable advancement of industrial expansion that is environmentally conscious, harmful dyes must be removed from wastewater. Untreated effluents containing colors have the potential to harm the ecosystem and pose major health risks to people, animals, and aquatic life. Here, we have fabricated Ni or Fe modified with BaTiO 3 materials and effectively utilized them for Reactive Red 120 (RR 120) dye degradation under UV-A light. The synthesized materials were characterized, and their structural, and photo-physical properties were reported. Phase segregation was not present in the XRD pattern, as evidenced by the absence of secondary phase peaks linked to iron, nickel, or oxides. Low metal ion concentrations may be the cause of this, and the presence of those elements was confirmed by XPS measurements. The Raman spectra of the BaTiO 3 /Ni and BaTiO 3 /Fe samples show a widened peak at 500 cm -1 , which suggests that Ni or Fe are efficiently loaded onto the BaTiO 3 . RR 120 dye photodegradation under UV light conditions was effectively catalyzed by BaTiO 3 /Fe, as evidenced by its superior performance in the UV irradiation technique over both BaTiO 3 and BaTiO 3 /Ni. Compared to bare BaTiO 3 , both metal-modified materials efficiently degraded the RR 120 dye. Acidic pH facilitated the degradation process, which makes sense given that the heterogeneous photo-Fenton reaction was the mechanism of degradation along with BaTiO 3 sensitization. High-acidity sewage can be dangerous and carcinogenic, and conventional biological treatment methods are not appropriate for managing it. In the current investigation, it may be used to treat color effluents with extremely low pH levels. Additionally, the ability of the produced nanocomposites to inhibit the growth of twenty pathogens was examined, along with two fungi, fifteen Gram-negative Bacilli (GNB), one Gram-positive Bacilli (GPB), and two Gram-positive Cocci (GBC)., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Cardiac troponin I (cTnI) is the most resorted biomarker for the detection of cardiovascular disease (CVD). The means of rapid quantification of cTnI levels in the blood can substantially minimize the risk of acute myocardial infarction and heart failure. A sensor for the non-enzymatic evaluation of cardiac troponin-I has been developed using fluorescent iron nanoclusters via a one-pot synthesis employing (BSA) as the template and reducing agent, and hydrogen peroxide as the additive. The fluorescence of Iron Nanocluster is quenched with graphene oxide (GO) via fluorescence resonance energy transfer (FRET) between conjugate iron nanoclusters and graphene oxide. The sensor shows a low detection limit of 0.011 ng/mL. The benefits of utilizing a non-enzymatic probe for detecting cardiac troponin I is that it avoids the need for enzymes and hence is economical, stable, and less impacted by environmental conditions such as temperature and pH. Non-enzymatic probes are more useful for clinical use since they are more stable and have a longer shelf life. The developed non-enzymatic probes are also highly selective and sensitive to the target analyte, making them suitable for the direct detection of cardiac troponin I in actual biological samples., (© 2024 Wiley-VCH GmbH.)

Excessive Fe 2+ in coastal aquaculture source water will seriously affect the aquaculture development. This study used manganese sand to investigate the removal potential and mechanism of Fe 2+ in coastal aquaculture source water by column experiments. The pseudo-first-order kinetic model could better describe Fe 2+ removal process with R 2 in the range of 0.9451-0.9911. More than 99.7% of Fe 2+ could be removed within 120 min while the removal rate (k) was positively affected by low initial concentration of Fe 2+ , high temperature, and low pH. Logistic growth (S-shaped growth) model could better fit the concentration variation of Fe 2+ in the effluent of the column (R 2 >0.99). The Fe 2 breakthrough curve could be fitted by Bohart-Adams, Yoon-Nelson, and Thomas models (R 2 >0.95). Smooth slices with irregular shapes existed on the surface of manganese sand after the reaction while Fe content increased significantly on the surface of manganese sand after the column experiment. Moreover, FeO (OH) was mainly formed on the surface of manganese sand after the reaction. PRACTITIONER POINTS: Fe 2+ in coastal aquaculture source water could be removed by manganese ores. The pseudo-first-order kinetic model better described the Fe 2+ removal process. FeO (OH) was mainly formed on the surface of manganese sand after the reaction., (© 2024 Water Environment Federation.)

To degrade phenol with the heterogeneous Fenton-like process and to compare the results, micro-scale zero-valent iron particles (mZVI) and nickel-coated iron bimetallic particles (Ni/Fe) were used. Oxygen was given to the system and converted to H 2 O 2 and •OH radicals. The changes in the properties of mZVI and Ni/Fe particles after the reaction were determined by scanning electron microscope (SEM), X-ray energy-dispersive spectrometer (EDX), Brunauer-Emmett-Teller (BET), X-ray powder diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) before and after the reaction. For phenol removal with an initial phenol concentration of 25 mg/L, initial pH of 3 and air flow rate of 150 L/h, 3 g/L dosage and 360 min reaction time for mZVI, 1.5 g/L dosage and 240 min for Ni/Fe reaction time were sufficient. Under these conditions, 76% and 98% phenol removal and 39% and 47% total organic carbon (TOC) removal were obtained for mZVI and Ni/Fe, while 189 and 85 mg/L H 2 O 2 were produced, respectively. While SO 4 - 2 and PO 4 - 3 caused a slight increase in phenol removal efficiency in the mZVI system, these ionic species and Cl - and NO 3 - caused a decrease in the efficiency in the Ni/Fe system. The possible degradation pathway for phenol was suggested by high performance liquid chromatography (HPLC) analysis and hydroquinone, pyrocatechol, maleic acid, benzoquinone and acetic acid were the main intermediates. According to the cost analysis, when using mZVI to treat 1 m 3 25 mg/L phenolic wastewater, the cost was $228.15, which was 1.45 times higher than the cost for Ni/Fe.

To meet the carbon-neutral goal in 2050, an accelerated transition of decarbonization is needed in the iron and steel industry. Lots of decarbonization path models are recently being used to analyze the technology pathways, industrial structure adjustments, and short- or long-term policies for greenhouse gas emission reduction. Thus, systematic insight is required for better making sense of the status quo and differences in low-carbon transition pathways at different levels. This paper reviews the carbon emission reduction of steel production routes and summarizes the decarbonization models from micro-, meso-, and macro-level perspectives, respectively. First, we systematically analyze the capacity and potential of both available and emerging technologies in the iron and steel production process. Additionally, we conduct a theoretical analysis of the bottom-up models currently used as effective tools to assess decarbonization technology pathways. Subsequently, pathways and models in terms of industrial synergy are elaborated. Policy guidance and market support are explored to overcome the challenges of collaborative carbon reduction faced by global steel producers. The characteristics of top-down models for supporting carbon reduction are also discussed. Finally, gaps in the literature and future research agendas are identified. Advancing this research could enrich discussions on steel industry decarbonization and provide clearer assessments of modeling approaches. The results indicate that existing energy-saving technologies in the iron and steel industry have limited carbon reduction capacity. Significant reduction requires coordinated efforts with upstream and downstream industries, particularly in hydrogen and power sectors, along with financial support and favorable policies., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Biochar produced from wood residues may provide a new method and material for managing the environment, particularly in terms of carbon sequestration and contaminant remediation. Additionally, biochar produced from wood residues is free of chemical fertilizers, likewise in rice straw, wheat straw, corn straw, etc. This study investigated the removal of iron from aqueous solutions by a novel low-cost and eco-friendly biochar made from hardwood trees and modified by adding MgCl 2 for effective phosphate removal. Optimal adsorption conditions were determined through studies of adsorption time, pH, and adsorbent dosage. Batch equilibrium isotherm and kinetic experiments and pre/post-adsorption characterizations using FESEM-EDS, XRD, and FTIR suggested that the presence of carboxyl group elements and colloidal and nano-sized MgO (periclase) particles on the biochar surface were the main adsorption sites for aqueous iron and phosphate respectively. In this study, the HW and MgO-HW biochar showed excellent Dubinin-Radushkevich isotherm (D-R) maximum adsorption capacities of 289.45 and 828.82 mg/g for iron and phosphate. The kinetic study for iron and phosphate adsorption was described well by pseudo second-order model and pseudo second-order model respectively. The HW biochar and the prepared MgO-HW biochar exhibited commendable iron adsorption (98.25%) performance at 10 pH units and phosphate (96.22%) at pH 6 respectively. Thus, this research reveals a waste-to-wealth strategy by converting hardwood waste into mineral-biomass biochar with excellent Fe and P adsorption capabilities and environmental adaptability., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

In this work, a multifunctional finishing agent named as PATFe was prepared from phytic acid (PA), tea polyphenols (TP), and Fe 3+ . The optimum weight ratio of PA to TP was determined by exploring the effect on flame retardant and tensile properties of viscose fabrics. Then, the effects of different concentrations of iron ions on the flame retardant and tensile properties of viscose fabrics were further investigated, and finally, multifunctional viscose fabrics, PATFe-9, were prepared. The system was investigated to confer the multifunctional effects on the flame retardant, bacteriostatic, and UV-resistant properties of viscose fabrics under the condition of lower weight gains (about 6.0 wt%). The limiting oxygen index of PATFe-9 reached 33.7 % with a weight gain of 6.1 wt%, and PATFe-9 had an inhibition effect against Staphylococcus aureus, and the ultraviolet protection factor value reached 67. It is worth noting that the breaking force retention rate of this system reached 100 %, which greatly improves the scope of use and added value of viscose fabrics., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

X-ray Photodynamic Therapy (XPDT) is an emerging, deeply penetrating, and non-invasive tumor treatment that stimulates robust antitumor immune responses. However, its efficacy is often limited by low therapeutic delivery and immunosuppressant within the tumor microenvironment. This challenge can potentially be addressed by utilizing X-ray responsive iron-glycol chitosan-polypyrrole nanozymes (GCS-I-PPy NZs), which activate M1 macrophages. These nanozymes increase tumor infiltration and enhance the macrophages' intrinsic immune response and their ability to stimulate adaptive immunity. Authors have designed biocompatible, photosensitizer-containing GCS-I-PPy NZs using oxidation/reduction reactions. These nanozymes were internalized by M1 macrophages to form RAW-GCS-I-PPy NZs. Authors' results demonstrated that these engineered macrophages effectively delivered the nanozymes with potentially high tumor accumulation. Within the tumor microenvironment, the accumulated GCS-I-PPy NZs underwent X-ray irradiation, generating reactive oxygen species (ROS). This ROS augmentation significantly enhanced the therapeutic effect of XPDT and synergistically promoted T cell infiltration into the tumor. These findings suggest that nano-engineered M1 macrophages can effectively boost the immune effects of XPDT, providing a promising strategy for enhancing cancer immunotherapy. The ability of GCS-I-PPy NZs to mediate M1 macrophage activation and increase tumor infiltration highlights their potential in overcoming the limitations of current XPDT approaches and improving therapeutic outcomes in melanoma and other cancers., Competing Interests: Declaration of competing interest All authors declare that no conflicts of interest exist., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Fluorescent probe with aggregation-induced emission (AIE) property has been widely used because of the advantages of high sensitivity, good selectivity and non-destructive testing. The development of fluorescent probe with good biocompatibility, photostability and biodegradability is of great significance in biomedicine and environmental detection. Herein, a novel type of fluorophore CS-TPE for detection of Fe 3+ and bacteria was prepared by the Schiff base reaction of chitosan (CS) and 4-(1,2,2-triphenylethenyl) benzaldehyde (TPE-CHO). The fluorescence response mechanism of CS-TPE system was investigated by various characterization techniques. CS-TPE had an obvious AIE behavior with strong blue-green emissions at 473 nm and reaches the highest photoluminescence (PL) emission in 90 % H 2 O/ethanol mixtures. CS-TPE fluorescent probe exhibited sensitive quenching response to Fe 3+ , which can be used as a biosensor for detecting the concentration of Fe 3+ with short response time (5 min), low detection limit (0.998 μM) and wide detection range (10-300 μM). Meanwhile, CS-TPE exhibited good antibacterial performance for S. aureus and E. coli. It is expected to realize the real-time fluorescence monitoring of metal ion detection and antibacterial process., Competing Interests: Declaration of competing interest The authors declare that there are no conflicts of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Application of fertilizers is a routine method in agriculture to increase the fertility of plants However, conventional fertilizers have raised serious health and environmental problems in recent years. Therefore, the development of biodegradable superabsorbent hydrogels based on natural polymers with the capability for fertilizer controlled release has attracted much interest. In the current research, a novel nanocomposite hydrogel based on gelatin and carboxymethyl cellulose polymers enriched with an iron based metal- organic framework (MIL-53 (Iron)) was prepared. The prepared nanocomposite hydrogel was loaded with NPK fertilizer to obtain a slow release fertilizer system. The structural properties of the nanocomposite hydrogel were investigated using FTIR, XRD, and SEM techniques. The swelling and fertilizer release behavior of the nanocomposite hydrogel were evaluated in conditions. Results showed that by adding iron-based metal organic framework to the hydrogel matrix, the water absorption capacity of the hydrogel system was increased to 345.8 (g/g). Fertilizer release studies revealed that the release of fertilizer from the nanocomposite matrix has a slow and continuous release pattern. Therefore, the synthesized nanocomposite has an appropriate strength and high potential to be used as a slow-release fertilizer system., Competing Interests: Declaration of competing interest There are no conflicts to declare., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Sewage sludge derived fertilizer is a promising solution for phosphorus (P) recovery from biowaste, however, the inherent iron content in the sludge ash (SSA) impedes the P availability of the fused calcium magnesium phosphate fertilizer (FCMP). To achieve the goal of iron removal during the process, carbothermal reduction was adopted for the first time and the performance of carbon addition was systematically evaluated. Results showed that carbon addition at 4.50 % significantly increased the P availability from 9.50 % to 11.00 % and decreased the required amounts of calcium/magnesium. Moreover, ferrophosphate with 20.20 % P can be produced and the melting point of the system can be reduced by manipulating carbon addition. Finally, a process design was provided for the co-production of FCMP and ferrophosphate. This study highlights the addition of carbon to facilitate iron removal in SSA for the production of FCMP with enhanced bioavailability at a reduced energy consumption scenario., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Amine functionalized bentonites were used as adsorbents for the bioremoval of Fe(III) ions, which led to the inclusion of functional groups such as -OH, -NH2, -OCH3, etc. FTIR, XRD, SEM, AFM, TG, BET, XRF, and CHNS analyzer were used to analyze the surface and textural characteristics. The influence of adsorption factors, such as pH, contact time, temperature, and initial concentration, have been investigated and tailored in batch adsorption experiments of Fe (III) metal ions. The maximum adsorption efficiency and capacity of modified BNT-APTMS is 100.90 % and 103.91 mg/g respectively. The adsorption process is best fit with Freundlich model (R 2 =0.998) than Langmuir model (R 2 =0.788) and the Temkin model D-R isotherm parameters indicating a physisorption process. A mechanism of spontaneous complexation was accomplished, because of the heterogeneity of the surface, electrostatic forces, pore filling, and π-π stacking. Follows PSO kinetics and favours Freundlich isotherm. The adsorbent substance showed a remarkable capacity for regeneration, assuring the substance's stability and reusability., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Diclofenac (DCF) is frequently detected in aquatic environments, emphasizing the critical need for its efficient removal globally. Here, we present the synthesis of Fe(III)-doped β-CD-grafted chitosan (Fe/β-CD@CS) cryogel beads designed for adsorbing DCF in aqueous solutions. The beads exhibited an average size of 2.94 ± 0.66 mm and a point of zero charge of 8.03. Adsorption experiments demonstrated that the Langmuir kinetic model provided the most accurate description of the kinetic data, while the Redlich-Peterson isotherm offered the best fit for the equilibrium data. The beads showcased a theoretical maximum adsorption capacity of 712.3 mg/g for DCF, with the adsorption process being identified as exothermic. DCF adsorption on the beads was attributed to hydrogen bonding, metal cation-π interactions, and electrostatic interactions. Reusability tests exhibited that the beads could be regenerated using 0.1 M NaOH. To perform deep learning modeling, adsorption experiments (n = 17), designed utilizing central composite design (CCD), were conducted in duplicate. The CCD framework incorporated input variables such as initial DCF concentration, adsorbent dosage, and solution pH, while the output variable was the DCF removal rate. Utilizing the adsorption data, an artificial neural network (ANN) model was constructed with a topology of 3: 7:10:1, featuring 3 input variables, 7 neurons in the first hidden layer, 10 neurons in the second layer, and 1 output variable. Employing the ANN model data, 3-D response surface plots were generated to elucidate the relationship between input variables and DCF removal rate. Additional adsorption tests were conducted to evaluate the developed ANN model, affirming its reliable predictability for the DCF removal rate. Analysis of the relative importance of the input variables revealed the following order of importance: solution pH (100 %) > adsorbent dosage (75.2 %) > initial DCF concentration (57.7 %)., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Tetracycline hydrochloride (TCH) removal from wastewater has drawn much attention recently, although it still remains challenging. Herein, Fe-based metal-organic frameworks (MOFs) incorporated nanofibrous membranes were prepared by green electrospinning and applied as adsorbents to remove TCH. The presence of MOFs noticeably improved specific surface area of the nanofibrous membranes, and adsorption capability increased with the amount of MOFs within membranes. As the temperature increased, the amount of TCH that was adsorbed continuously reduced, and the maximum adsorption capacity (248.5 mg/g) was attained at 273 K. The adsorption behavior of the nanofibrous membranes followed Langmuir isotherm model and pseudo-second-order kinetic model. Thermodynamic parameters suggested that the adsorption process was spontaneous and exothermic. A series of interactions between the membrane and TCH, such as pore filling, coordination bonding, π-π interaction, hydrogen bonding interaction and electrostatic interaction, combined to enhance the adsorption performance. Good stability and adsorption capability were demonstrated by the nanofibrous membranes, suggesting that they could be used for effective and affordable water purification., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Dual electron donor bioretention systems have emerged as a popular strategy to enhance dissolved nitrogen removal from stormwater runoff. Pyrite-woodchip mixotrophic bioretention systems showed a promoted and stabilized removal of dissolved nutrients under complex rainfall conditions, but the sulfate reduction process that can induce iron sulfide generation and reuse was overlooked. In this study, experiments and models were applied to investigate the effects of filler configuration and dissolved organic carbon (DOC) dissolution rate on treatment performance and iron sulfide generation in pyrite-woodchip bioretention systems. Key parameters govern that DOC dissolution and microbe-mediated processes were obtained by experiments. The water quality models that integrate one-dimensional constant flow, sorption and microbial transformation kinetics were used to predict the performance of bioretention systems. Results showed that the mixotrophic bioretention system with woodchip mixed in the vadose zone and pyrite in the saturated zone achieves a better performance in both nitrogen removal efficiency and by-product control. Comparably, woodchip and pyrite mixed in the saturated zone could encounter a high secondary pollution risk. The sensitivity coefficients of oxic/anoxic DOC dissolution rates to total nitrogen removal are 0.36 and -2.43 respectively. Iron sulfide generation was affected by DOC distribution and the competition between heterotrophic denitrifiers, autotrophic denitrifiers, and sulfate-reducing bacteria (SRB). DOC accumulation has an antagonistic effect on iron production and sulfate reduction. Extra DOC accumulation favors sulfate reduction while high DOC concentration inhibits pyrite-based denitrification and reduces Fe(III) production. The recycling of iron sulfide can improve the robustness and sustainability of bioretention systems., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Phosphorus (P) recovered from sludge-incinerated ash (SIA) could be applied to synthesize highly added-value products (FePO 4 and LiFePO 4 ) with in situ Fe in SIA. Indeed, LiFePO 4 is a future of rechargeable batteries, which makes lithium (Li) highly needed. Alternatively, Li could also be extracted from concentrated brines to face a potential crisis of Li depletion on lands. Based on H 3 PO 4 and Fe 3+ co-extracted from the acidic leachate of SIA by tributyl phosphate (TBP), FePO 4 (31.2 wt% Fe, 17.6 wt% P and the molar ratio of Fe/P = 0.98) was easily formed only adjusting pH of the stripping solution to 1.6. Interestingly, the organic phase from the first-stage co-extraction process of Fe 3+ and H 3 PO 4 could be utilized for Li-extraction from salt-lake brine, based on the TBP-FeCl 3 -kerosene system, and a good performance (78.7%) of Li-extraction and separation factors (β) (186.0-217.4) were obtained. Furthermore, the compounds with Li-extraction are complex, possibly LiFeCl 4 ∙2TBP, in which Li + could be stripped to form Li 2 CO 3 by 4.0 M HCl (with a stripping rate up to 83%). Besides, Li 2 CO 3 could also be obtained from desalinated brine by adsorption with manganese oxide ion sieve (HMO) and desorption with HCl. In the two cases, almost pure Li 2 CO 3 products were obtained, up to 99.7 and 99.5 wt% Li 2 CO 3 respectively, after further purification and concentration. Finally, recovered FePO 4 and extracted Li 2 CO 3 were synthesized for producing LiFePO 4 that had a similar electrochemical property (69.5 and 77.8 mAh/g of the initial discharge capacity) to those synthesized from commercial raw materials., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

A lot of attention has been drawn to photo-Fenton-like catalysis among advanced oxidation processes for environmental remediation applications. Herein, we have successfully fabricated iron-nickel bimetallic magnetic nano-alloy (INBMNA) as an efficient heterogeneous photo-Fenton-like catalyst using the chemical reduction method and characterized by several analytical techniques. The characterization results show that the catalyst has a spherical shape with a mesoporous nature and contains a large specific surface area. The impact of various parameters was investigated and optimized to check the catalytic performance of INBMNAs and the found results showed that excellent photo-Fenton-like activity persisted under 6.0 pH conditions for the degradation of hazardous pollutant (phenol) under solar light exposure and microwave radiation power, respectively. Additionally, the exposed INBMNA/H 2 O 2 system provided continuous redox cycles of Fe 3+ /Fe 2+ and Ni 2+ /Ni 0 pair in the Fenton-active species for stable operation. The photo-Fenton-like activity was also performed to check the effect of different inorganic anions which significantly hinder phenol reduction. Besides, the steady performance of the catalyst to remove phenol was performed in tap water and river water. Free radical trapping experiments were tested to know the role of important radicals in the photo-Fenton process. Moreover, the mechanism and possible degradation pathways of phenol were checked. By cyclic degradation experiments, the performance of the catalyst is stable and almost unchanged and can be reused several times. This study provides a promising INBMNA/H 2 O 2 system, which encourages its widespread use in environmental remediation applications., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:, (Copyright © 2024 Elsevier Ltd. All rights reserved.)

In this study, a one-step solvothermal method was used to fabricate Fe 3+ doped BiOCl microflowers with abundant oxygen vacancies (OVs) in the presence of glacial acetic acid. Various analytical techniques were employed to characterize the structural, morphological, and optical properties of the prepared samples. The presence of OVs was confirmed by low temperature electron paramagnetic resonance (EPR) analysis. The photocatalytic results show that Fe 3+ doped BiOCl photocatalysts have higher activity than the bare BiOCl, and 10% Fe 3+ /BiOCl exhibits the highest photocatalytic performance, the photocatalytic efficiency of this sample is 2.3 and 1.1 times higher than that of the blank BiOCl toward photocatalytic degradation of perfluorooctanoic acid (PFOA) and rhodamine B (RhB), respectively. Furthermore, Fe 3+ doped BiOCl demonstrates excellent reusability. Based on the experimental observations, an enhancement mechanism for the photocatalytic activity of Fe 3+ doped BiOCl was reasonably elucidated.

High energy consumption has seriously hindered the development of Fenton-like reactions for the removal of refractory organic pollutants in water. To solve this problem, we designed a novel Fenton-like catalyst (Cu-PAN 3 ) by coprecipitation and carbon thermal reduction. The catalyst exhibits excellent Fenton-like catalytic activity and stability for the degradation of various pollutants with low H 2 O 2 consumption. The experimental results indicate that the dual reaction centers (DRCs) are composed of Cu-N-C and Cu-O-C bridges between copper and graphene-like carbon, which form electron-poor/rich centers on the catalyst surface. H 2 O 2 is mainly reduced at electron-rich Cu centers to free radicals for pollutant degradation. Meanwhile, pollutants can be oxidized by donating electrons to the electron-poor C centers of the catalyst, which inhibits the ineffective decomposition of H 2 O 2 at the electron-poor centers. This therefore significantly reduces the consumption of H 2 O 2 and reduces energy consumption., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)

Natural attapulgite (ATP) is a promising substitute for existing artificial nanozymes due to its intrinsic enzymatic activity. However, the active center of ATP's inherent enzymatic activity has not yet been revealed, which limits its further design and activity optimization. Studying the active center of mineral materials can be extremely challenging due to their complexity. Here, we demonstrated that Fe is the primary element in ATP responsible for peroxidase (POD)-like activity through theoretical speculation and experimental verification. More importantly, we found that the ratio of Fe 2+ /Fe 3+ is responsible for the district POD-like activity of ATP from different regions with the same Fe content. Additionally, three facile strategies, including grinding, heat treatment, and acid treatment, were demonstrated to increase the relative Fe content and thus optimize the POD-like activity of ATP. Finally, ATP was used to detect the concentration of H 2 O 2 , enabling the detection of low concentrations (0.11-1.76 mM) of H 2 O 2 . This study serves as a novel reference for the future design and performance optimization of nanozymes that are based on ATP and clay minerals., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH, DE part of Springer Nature.)

Water splitting has emerged as a promising route for sustainable hydrogen production. In this research paper, adsorption and dissociation of H 2 O accompanied with dissociated constituents reactions with CO 2 and CO have been investigated on Fe modified Cu(100) surface employing density functional theory (DFT) at GGA-PW91 level. The adsorption and other reactions carried out on Fe2-Cu(100) surfaces gave very promising results. The adsorption of H 2 O on Fe top of this surface occurs yielding E ads -1.73 eV, which highlights a favorable adsorption on the Fe-modified Cu(100) surface. The activation energy for the water splitting reaction is found to be 0.65 eV, suggesting a feasible pathway for hydrogen evolution. The process also accompanies reaction energy of -0.54 eV. Furthermore, the interaction between carbon dioxide (CO 2 ) and the H-atom on the surface lead to the formation of COOH through surmounting an activation barrier of 1.09 eV. The final position of COOH gets further stabilization having exothermicity of -0.43 eV. Another route for COOH formation from CO + OH operates on the Cu(100) part of the surface with a small activation barrier of 0.14 eV through exothermic process of -0.29 eV, however, diffusion of CO and OH from Fe to Cu is energetically expensive. This study signifies the consumption of CO and CO 2 in addition to water splitting giving birth to useful products., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Nanozymes are nanomaterials with mimetic enzyme properties and the related research has attracted much attention. It is of great value to develop methods to construct nanozymes and to study their application in bioanalysis. Herein, the metal-ligand cross-linking strategy was developed to fabricate superstructure nanozymes. This strategy takes advantage of being easy to operate, adjustable, cheap, and universal. The fabricated superstructure nanozymes possess efficient peroxidase-like catalytic activity. The enzyme reaction kinetic tests demonstrated that for TMB and H 2 O 2 , the K m is 0.229 and 1.308 mM, respectively. Furthermore, these superstructure nanozymes are applied to highly efficient and sensitive detection of glucose. The linear range for detecting glucose is 20-2000 μM, and the limit of detection is 17.5 μM. Furthermore, mechanistic research illustrated that this integrated system oxidizes glucose to produce hydrogen peroxide and further catalyzes the production of · OH and O 2 ·- , which results in a chromogenic reaction of oxidized TMB for the detection of glucose. This work could not only contribute to the development of efficient nanozymes but also inspire research in the highly sensitive detection of other biomarkers., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH, DE part of Springer Nature.)

Nano-zero valent iron (nZVI) was anchored and dispersed on the surface of acid-modified blast furnace slag (mBFS) through the liquid phase reduction method. The synthesized nZVI@mBFS composite exhibited remarkable ability to degrade phenol when used in conjunction with persulfate (PDS), 97.8% phenol could be eliminated in 30 min. All the anions like SO 4 2- , HCO 3 - , H 2 PO 4 - , and CO 3 2- were detrimental to the phenol degradation in nZVI@mBFS system. Moreover, electron paramagnetic resonance (EPR) analysis and radical scavenging tests confirmed that SO 4 •- , •OH and •O 2 - were the principal reactive oxygen species (ROSs) generated during the reaction process. The potential degradation pathways were also deduced based on the results obtained from gas chromatograph-mass spectrometer (GC-MS) analysis. Collectively, this study holds substantial significance in regards to recycling industrial solid wastes, devising efficient persulfate-activated materials, and treating wastewater., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Fenton-like processes using persulfate for oxidative water treatment and contaminant removal can be enhanced by the addition of redox-active biochar, which accelerates the reduction of Fe(III) to Fe(II) and increases the yield of reactive species that react with organic contaminants. However, available data on the formation of non-radical or radical species in the biochar/Fe(III)/persulfate system are inconsistent, which limits the evaluation of treatment efficiency and applicability in different water matrices. Based on competition kinetics calculations, we employed different scavengers and probe compounds to systematically evaluate the effect of chloride in presence of organic matter on the formation of major reactive species in the biochar/Fe(III)/persulfate system for the transformation of the model compound N,N‑diethyl-m-toluamide (DEET) at pH 2.5. We show that the transformation of methyl phenyl sulfoxide (PMSO) to methyl phenyl sulfone (PMSO 2 ) cannot serve as a reliable indicator for Fe(IV), as previously suggested, because sulfate radicals also induce PMSO 2 formation. Although the formation of Fe(IV) cannot be completely excluded, sulfate radicals were identified as the major reactive species in the biochar/Fe(III)/persulfate system in pure water. In the presence of dissolved organic matter, low chloride concentrations (0.1 mM) shifted the major reactive species likely to hydroxyl radicals. Higher chloride concentrations (1 mM), as present in a mining-impacted acidic surface water, resulted in the formation of another reactive species, possibly Cl 2 •- , and efficient DEET degradation. To tailor the application of this oxidation process, the water matrix must be considered as a decisive factor for reactive species formation and contaminant removal., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

The presence of organic phosphorus may influence the characteristics of Cr(VI) reduction and immobilization on Fe(II)-bearing clay minerals under anoxic conditions, as the organic phosphorus tends to bind strongly to clay minerals in soil. Herein, reduced nontronite (rNAu-2) was used to reduction of Cr(VI) in the presence of phytic acid (IHP) at neutral pH. With IHP concentration from 0 to 500 μM, Cr(VI) reduction decreased obviously (17.8%) within first 5 min, and then preferred to stagnate during 4-12 h (≥50 μM). After that, Cr(VI) was reduced continuously at a slightly faster rate. Density functional theory (DFT) calculations revealed that IHP primarily absorbed at the edge sites of rNAu-2 to form Fe-IHP complexes. X-ray diffraction (XRD), scanning transmission electron microscopy (STEM), and Fourier transform infrared spectroscopy (FTIR) results demonstrated that IHP hindered the ingress of CrO 4 2- into the interlayer space of rNAu-2 and impeded their reduction by trioctahedral Fe(II) and Al-Fe(II) at basal plane sites in the initial stage. Additionally, Fe(II) extraction results showed that IHP promoted the electron from interior transfer to near-edge, but hindered it further transfer to surface, resulting in the inhibition on Cr(VI) reduction at edge sites during the later stage. Consequently, IHP inhibits the reduction and immobilization of Cr(VI) by rNAu-2. Our study offers novel insights into electron transfer pathways during the Cr(VI) reduction by rNAu-2 with coexisting IHP, thereby improve the understanding of the geochemical processes of chromium within the iron cycle in soil., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)