Enhanced low-concentration phosphate adsorption using magnetic UiO-66@Fe3O4 composite with potential linker exchange.

A magnetic FenUiO-66 adsorbent was created to achieve high phosphate adsorption capacity. The incorporation of Fe3O4 facilitated the precipitation and growth of UiO-66 during crystallization, resulting in a shift towards a multilayer heterogeneous distribution of adsorption sites. The increased Fe3O4 content notably enhanced the magnetic properties of FenUiO-66, while negligibly affecting its adsorption performance. The Fe1.5UiO-66 demonstrated exceptional phosphate adsorption capacity (136.54 mg/g), outstanding selectivity, and sustained reusability, with an 80% removal efficiency after nine cycles of treating actual water. The mechanism of phosphate adsorption by FenUiO-66 involved electrostatic attraction, ligand exchange, and linker exchange. Notably, while linker exchange significantly contributed to high adsorption capacity, it resulted in irreversible damage to the FenUiO-66 crystal. These unequivocal findings will serve as a solid foundation for further research and underline the critical role of linkers in the process of phosphate adsorption.

Polyphenol supplementation boosts aerobic endurance in athletes: systematic review.

In recent years, an increasing trend has been observed in the consumption of specific polyphenols, such as flavonoids and phenolic acids, derived from green tea, berries, and other similar sources. These compounds are believed to alleviate oxidative stress and inflammation resulting from exercise, potentially enhancing athletic performance. This systematic review critically examines the role of polyphenol supplementation in improving aerobic endurance among athletes and individuals with regular exercise habits. The review involved a thorough search of major literature databases, including PubMed, Web of Science, SCOPUS, SPORTDiscus, and Embase, covering re-search up to the year 2023. Out of 491 initially identified articles, 11 met the strict inclusion criteria for this review. These studies specifically focused on the incorporation of polyphenols or polyphenol-containing complexes in their experimental design, assessing their impact on aerobic endurance. The methodology adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and the risk of bias was evaluated using the Cochrane bias risk assessment tool. While this review suggests that polyphenol supplementation might enhance certain aspects of aerobic endurance and promote fat oxidation, it is important to interpret these findings with caution, considering the limited number of studies available. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42023453321.

PTEN Inhibitor Treatment Lowers Muscle Plasma Membrane Damage and Enhances Muscle ECM Homeostasis after High-Intensity Eccentric Exercise in Mice.

Exercise-induced muscle damage (EIMD) is a common occurrence in athletes and can lead to delayed onset muscle soreness, reduced athletic performance, and an increased risk of secondary injury. EIMD is a complex process involving oxidative stress, inflammation, and various cellular signaling pathways. Timely and effective repair of the extracellular matrix (ECM) and plasma membrane (PM) damage is critical for recovery from EIMD. Recent studies have shown that the targeted inhibition of phosphatase and tension homolog (PTEN) in skeletal muscles can enhance the ECM environment and reduce membrane damage in Duchenne muscular dystrophy (DMD) mice. However, the effects of PTEN inhibition on EIMD are unknown. Therefore, the present study aimed to investigate the potential therapeutic effects of VO-OHpic (VO), a PTEN inhibitor, on EIMD symptoms and underlying mechanisms. Our findings indicate that VO treatment effectively enhances skeletal muscle function and reduces strength loss during EIMD by upregulating membrane repair signals related to MG53 and ECM repair signals related to the tissue inhibitor of metalloproteinases (TIMPs) and matrix metalloproteinase (MMPs). These results highlight the potential of pharmacological PTEN inhibition as a promising therapeutic approach for EIMD.

Sustained-release nitrate combined with microbial fuel cell: A novel strategy for PAHs and odor removal from sediment.

Nitrate addition is a biostimulation technique that can improve both the oxidation of acid volatile sulfide (AVS) through autotrophic denitrification and the biodegradation of polycyclic aromatic hydrocarbons (PAHs) via heterotrophic denitrification. However, during the remediation, parts of the dissolved nitrate in the sediment migrates from the sediment to the overlying water, leading to the loss of effective electron acceptor. To overcome this limitation, a combined approached was proposed, which involved nitrocellulose addition and a microbial fuel cell (MFC). Results indicated the nitrate could be slowly released and maintained at a higher concentration over long term. In the combined system, the removal efficiencies of PAHs and AVS were 71.56% and 89.76%, respectively. Furthermore, the voltage attained for the MFC-nitrocellulose treatment was maintained at 146.1 mV on Day 70, which was 5.37 times higher than that of the MFC-calcium nitrate treatment. Sediments with nitrocellulose resulted in lower levels of nitrate and ammonium in the overlying water. Metagenomic results revealed that the combined technology improved the expression of nitrogen-cycling genes. The introduction of MFC inhibited sulfide regeneration during incubation by suppressing the enzyme activity like EC4.4.1.2. The enhanced biostimulation provided potential for in-situ bioremediation utilizing MFC coupled with slow-released nitrate (i.e., nitrocellulose) treatment.

Improve the Crosslinking Reactivity of Nitrile: Design of Nitrile-Functionalized Pyrazine and its Hydrogen Bond-Assisted Nucleophilic Enhancement Study.

In this study, molecular engineering and biomimetic principles are utilized to prepare highly effective nitrile-functionalized pyrazine crosslinking units by exploiting pyrazine's unique nucleophilic strengthening mechanism and proton bonding ability. The curing behaviors of pyrazine-2,3-dicarbonitrile and phthalonitrile are investigated through model curing systems and molecular simulation. The results indicate that pyrazine-2,3-dicarbonitrile exhibits higher reactivity than phthalonitrile, promoted by amine. The cured products of pyrazine-2,3-dicarbonitrile predominantly comprise thermally stable azaisoindoline and azaphthalocyanine. This novel type of highly effective crosslinking unit, and the comprehended mechanism of action of pyrazine at the molecular level, significantly expand the application of pyrazine in materials science.

'Green-to-Green': Iron oxides embedded in lignin-based carbon scaffolds for water remediation via oxidation excluding free-radical pathways.

Advanced oxidation processes (AOP) are a common tool to remove organic compounds from the water cycle. The process is mostly relied on free radicals (i.e., SO4•- and HO•) with high oxidation power in solution. Surface-mediated mechanism could improve this process to prevent undesired quenching of aqueous radicals that widely exists in free radical pathways and alleviate metal leaching through direct electron transfer. In this work, a facile low-temperature pre-treatment combined with pyrolytic strategy was employed to construct a green catalyst with iron oxides embedded in Kraft-lignin derived bio-char (γ-Fe2O3 @KC), upon which radicals stay surface mediated and the activity-stability trade-off is achieved for pollutant degradation. The γ-Fe2O3 @KC is capable of activating PMS to generate non-radical species which are more stable (1O2 and Fe(V)=O) and of enhancing electron transfer efficiency. A surface-bound reactive complex (Catalyst-PMS*) was identified by electrochemical characterization and was discussed with primary surface-bound radical pairs to explain the contradictions between quenching and EPR detection results. We analyzed the γ-Fe2O3 @KC as a PMS-activating catalyst for a wider range of oxidation targets, such as Rhodamine B (∼100%), p-nitrophenol (∼85%), and Ciprofloxacin (∼63%), and found competitive removal efficiencies. The system also shows an encouraging reusability for at least 5 times and high stability at pH 3-9, and the low concentration of iron in γ-Fe2O3 @KC/PMS system implies the carbon scaffold of biochar alleviate the leakage process. The combined findings highlight the applicability in 'green (source) to green (application)' processes using cost-effective and bio-friendly iron@carbon catalysts, where alternative oxidation pathways are activated to play a dominant role for water purification.

Scaled-up development of magnetically recyclable Fe3O4/La(OH)3 composite for river water phosphate removal: From bench-scale to pilot-scale study.

The use of magnetic lanthanum-based materials for phosphate removal from river water has gained increasing attention. However, challenges to produce and use lanthanum-based materials in large-scale or pilot-scale studies remain. In this work, a kilogram-scale Fe3O4/La(OH)3 magnetically recyclable composite for removing phosphate from river water was developed through a low-temperature precipitation route. The composite was used to remove phosphate from river water at both bench- and pilot-scales. Based on the bench-scale tests, the developed Fe3O4/La(OH)3 composite was found to have excellent magnetic particle separation efficiency (>98%) and a sorption capacity of 11.77 mg/g for phosphate. A 1.0 g/L dosage of the composite in the river water sample was able to selectively reduce the phosphate level from 0.089 to 0.005 mg/L in 60 min over five consecutive adsorption cycles. At the pilot-scale, the Fe3O4/La(OH)3 composite only achieved 36.0% phosphate removal efficiency, which is considerably different from the bench-scale results over an operational time of five months and a total treatment volume of 300 m3. This significantly reduced removal efficiency is mainly attributable to turbidity, suspended solids, and organic matter in the river water and the deteriorated magnetic separation efficiency. This study revealed potential challenges and shed new insights on moving magnetic nanocomposite-based technology from the bench-scale to the pilot-scale, which can inspire new designs for the application of similar technology.

Role of surface functional groups of hydrogels in metal adsorption: From performance to mechanism.

Hydrogels have been studied quite intensively in recent decades regarding whether their metal adsorption abilities may be modified or even enhanced via functionalization (i.e., functionalizing the surfaces of hydrogels with specific functional groups). Studies have found that functionalizing hydrogels can in fact give them higher adsorptive power. This enhanced adsorptive performance is articulated in this paper through critically reviewing more than 120 research articles in such terms as the various techniques of synthesizing functionalized hydrogels, the roles that specific functional groups play on adsorption performance, selectivity, reusability, as well as on adsorption mechanism. Moreover, this critical review offers insight into future designs of functionalized hydrogels with specific metal adsorption capabilities.

Surface Functional Group Engineering of CeO2 Particles for Enhanced Phosphate Adsorption.

Surface functional groups play a dominating role in determining the adsorption performance of metal oxide particles. The ability to manipulate the surface functional groups is vital in designing an effective adsorbent for water decontamination. In this study, a facile method is proposed for tuning the amount of the surface hydroxyl groups of CeO2 particles. The volume of water added during the ethylene glycol-mediated solvothermal synthesis of CeO2 particles can be used to adjust the amount of surface hydroxyl groups. By simple reduction in the volume of water, the number of surface hydroxyl groups of CeO2 particles can be increased and the phosphate adsorption capacity can be greatly improved. Our results show that the obtained CeO2 particles have high phosphate adsorption capacity at low phosphate concentrations, fast adsorption kinetics, and the ability to achieve an ultralow phosphate concentration in the real sewage effluent. This study provides an effective strategy for designing highly effective metal oxide adsorbents through surface functional group engineering.

Selective Phosphate Removal from Water and Wastewater using Sorption: Process Fundamentals and Removal Mechanisms.

Eutrophication of water bodies is a serious and widespread environmental problem. Achieving low levels of phosphate concentration to prevent eutrophication is one of the important goals of the wastewater engineering and surface water management. Meeting the increasingly stringent standards is feasible in using a phosphate-selective sorption system. This critical review discusses the most fundamental aspects of selective phosphate removal processes and highlights gains from the latest developments of phosphate-selective sorbents. Selective sorption of phosphate over other competing anions can be achieved based on their differences in acid-base properties, geometric shapes, and metal complexing abilities. Correspondingly, interaction mechanisms between the phosphate and sorbent are categorized as hydrogen bonding, shape complementarity, and inner-sphere complexation, and their representative sorbents are organic-functionalized materials, molecularly imprinted polymers, and metal-based materials, respectively. Dominating factors affecting the phosphate sorption performance of these sorbents are critically examined, along with a discussion of some overlooked facts regarding the development of high-performance sorbents for selective phosphate removal from water and wastewater.

Lanthanum oxide nanorods for enhanced phosphate removal from sewage: A response surface methodology study.

Lanthanum-based adsorbents are ideal candidates for phosphate removal because of their excellent affinity to phosphate. However, their application in the removal of trace-levels of phosphate from sewage is still unsatisfactory due to the limited adsorption capacity and inadequate optimization of the operational parameters. To overcome these drawbacks, we have developed a novel lanthanum hydroxide (LH), using a facile precipitation and hydrothermal process that involves a nanorod-like structure with the lengths ranging from 124 to 1700 nm, depending on the La/OH molar ratio. The phosphate adsorption capacity of the developed LH is up to 170.1 mg-P g-1 in synthetic water, while a slightly lower adsorption capacity of 111.1 mg-P g-1 is observed in a sewage sample. A polynominal model consisting of three variables (i.e. dosage, reaction time and initial phosphate concentration) for predicting efficiency of phosphate removal has been successfully developed using a face-centred central composite design (CCD)-based methodology. The results also suggest a strong interactive effect of the dosage with the phosphate concentration, and reaction time, which can significantly affect the optimization of the phosphate removal by LH. Both X-ray photoelectron spectroscopy and X-ray diffraction studies indicate that the inner sphere complexation of phosphate with LH is probably the major mechanism governing phosphate removal.

Removal Mechanisms of Phosphate by Lanthanum Hydroxide Nanorods: Investigations using EXAFS, ATR-FTIR, DFT, and Surface Complexation Modeling Approaches.

Lanthanum-based materials are effective for sequestering phosphate in water, however, their removal mechanisms remain unclear, and the effects of environmentally relevant factors have not yet been studied. Hereby, this study explored the mechanisms of phosphate removal using La(OH)3 by employing extended X-ray absorption spectroscopy (EXAFS), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), density functional theory (DFT) and chemical equilibrium modeling. The results showed that surface complexation was the primary mechanism for phosphate removal and in binary phosphate configurations, namely diprotonated bidentate mononuclear (BM-H2) and bidentate binuclear (BB-H2), coexisting on La(OH)3 in acidic conditions. By increasing the pH to 7, BM-H1 and BB-H2 were the two major configurations governing phosphate adsorption on La(OH)3, whereas BB-H1 was the dominant configuration of phosphate adsorption at pH 9. With increasing phosphate loading, the phosphate configuration of on La(OH)3 transforms from binary BM-H1 and BB-H2 to BB-H1. Amorphous Ca3(PO4)2 forms in the presence of Ca, leading to enhanced phosphate removal at alkaline conditions. The contributions of different mechanisms to the overall phosphate removal were successfully simulated by a chemical equilibrium model that was consistent with the spectroscopic results. This study provides new insights into the molecular-level mechanism of phosphate removal by La(OH)3.

Highly efficient and selective phosphate removal from wastewater by magnetically recoverable La(OH)3/Fe3O4 nanocomposites.

The use of lanthanum (La)-based materials for phosphate removal from water and wastewater has received increasing attention. However, challenges remain to enhance phosphate sorption capacities and recover La-based sorbents. In this study, magnetic La(OH)3/Fe3O4 nanocomposites with varied La-to-Fe mass ratios were synthesized through a precipitation and hydrothermal method. Based upon preliminary screening of synthesized La(OH)3/Fe3O4 nanocomposites in terms of phosphate sorption capacity and La content, La(OH)3/Fe3O4 nanocomposite with a La-to-Fe mass ratio of 4:1 was chosen for further characterization and evaluation. Specifically, for these materials, magnetic separation efficiency, phosphate sorption kinetics and isotherm behavior, and solution matrix effects (e.g., coexisting ions, solution pH, and ionic strength) are reported. The developed La(OH)3/Fe3O4 (4:1) nanocomposite has an excellent magnetic separation efficiency of >98%, fast sorption kinetics of 30 min, high sorption capacity of 83.5 mg P/g, and strong selectivity for phosphate in presence of competing ions. Phosphate uptake by La(OH)3/Fe3O4 (4:1) was pH-dependent with the highest sorption capacities observed over a pH range of 4-6. The ionic strength of the solution had little interference with phosphate sorption. Sorption-desorption cyclic experiments demonstrated the good reusability of the La(OH)3/Fe3O4 (4:1) nanocomposite. In a real treated wastewater effluent with phosphate concentration of 1.1 mg P/L, 0.1 g/L of La(OH)3/Fe3O4 (4:1) efficiently reduced the phosphate concentration to below 0.05 mg P/L. Electrostatic attraction and inner-sphere complexation between La(OH)3 and P via ligand exchange were identified as the sorption mechanisms of phosphate by La(OH)3/Fe3O4 (4:1).