Redox Processes Research Articles

Original Direct Synthesis of Nanostructured MnO2 in Water by Hydroxylated Ammonium‐Assisted Redox Process

Original Direct Synthesis of Nanostructured MnO₂ in Water by Hydroxylated Ammonium‐Assisted Redox Process

Multiple Protophilic Redox-Active Sites in Reticular Organic Skeletons for Superior Proton Storage.

Protons (H+) with the smallest size and fastest redox kinetics are regarded as competitive charge carriers in the booming Zn-organic batteries (ZOBs). Developing new H+-storage organic cathode materials with multiple ultralow-energy-barrier protophilic sites and super electron delocalization routes to propel superior ZOBs is crucial but still challenging. Here we design multiple protophilic redox-active reticular organic skeletons (ROSs) for activating better proton storage, triggered by intermolecular H-bonding and π-π stacking interactions between 2,6-diaminoanthraquinone and 2,4,6-triformylphloroglucinol nanofibrous polymer. ROSs expose reticular electron delocalization geometries to fully access build-in protophilic carbonyl sites and promote ultrarapid H+ migration with an ultralow activation energy (0.13 vs. 0.29 eV of Zn2+ ions), thus delivering high capacity (359 mAh g-1) and large-current survivability (100 A g-1). Moreover, the extended interconnected reticular structures strengthen the anti-dissolution of ROSs in aqueous electrolytes, affording long-lasting proton-storage activity in ZOBs to a superior level (60,000 cycles at 20 A g-1). Systematic studies identify the source of excellent charge storage as high-kinetics H+-coupled five-electron redox process of carbonyl motifs in superstable ROSs. These findings can be of importance for evoking superior proton activity in multiple redox organics to build advanced Zn-organic batteries.

Operando Synchrotron X-Ray Absorption Spectroscopy: A Key Tool for Cathode Material Studies in Next-Generation Batteries.

Rechargeable batteries are central to modern energy storage systems, from portable electronics to electric vehicles. The cathode material, a critical component, largely dictates a battery's energy density, capacity, and overall performance. This review focuses on the application of operando X-ray absorption spectroscopy (XAS) to study cathode materials in Li-ion, Na-ion, Li-S, and Na-S batteries. Operando XAS provides real-time insights into the local electronic structure, oxidation states, and coordination environments, which are crucial for understanding complex electrochemical processes, such as redox reactions, phase transitions, and structural degradation. The review highlights the strengths of hard and soft XAS techniques in probing transition metal (TM) and anionic redox processes, particularly in layered oxide cathodes, where reversible oxygen redox and TM behavior are pivotal. The role of operando XAS is also explored in analyzing conversion-type S-based cathodes, where it helps unravel the intricate reaction mechanisms. Furthermore, the review addresses the challenges of in situ cell design for operando XAS, especially under ultrahigh vacuum conditions for soft XAS. By discussing recent advancements and future directions, this review underscores the critical role of operando XAS in driving innovation and improving the design and performance of next-generation battery technologies.

Quantum chemical study of molecular properties of small branched-chain amino acids in water

Four aliphatic amino acids—α-aminobutyric acid (AABA), β-aminobutyric acid (BABA), α-aminoisobutyric acid (AAIBA) and β-aminoisobutyric acid (BAIBA) were investigated in water as a solvent by two quantum chemical methods. B3LYP hybrid version of DFT was used for geometry optimization and a full vibrational analysis of neutral molecules, their cations and anions in the canonical and zwitterionic forms (6 forms for each species). Ab initio DLPNO-CCSD(T) method was applied in the geometry pre-optimized by B3LYP. Calculated molecular descriptors involve dipole moment, quadrupole moment, dipole polarizability, energy of zero-point vibration and total entropic term which enter the standard Gibbs energy. In addition, a set of collective electronic and thermodynamic properties associated with redox process were evaluated: ionization energy, electron affinity, chemical hardness, molecular electronegativity, electrophilicity index, absolute oxidation and reduction potentials. A mutual comparison of these structural isomers including γ-aminobutyric acid (GABA) shows high degree of similarity in molecular descriptors. However, cluster analysis of 12 electro neutral, linear and branched amino acids with 2 – 6 carbon atoms discriminates them into five clusters. It is found that the electrophilicity index correlates with the absolute reduction potential along a straight line (24 items). The reduction potential for canonical structure varies between 1.21 V (glycine) and 1.45 V (AABA) whereas for the zwitterionic form it is visibly lower 0.52–1.11 V. The highest absolute reduction potential > 1.43 V is shown by α-amino acids: α-alanine, AABA (homoalanine) and AAIBA having 2-methyl or 2-ethyl functional group. The calculated absolute oxidation potential correlates with the adiabatic ionization energy and can be used as a criterion of the antioxidant capacity. According to thermodynamic data, the SPLET mechanism of the electron-proton coupled transfer is favored over the alternative SET-PT mechanism. This work contributes to the creation of a database of molecular properties of amino acids based on the same method and basis set.

Redox-Active Bisphosphonate-Based Viologens as Negolytes for Aqueous Organic Flow Batteries.

Viologen derivatives feature two reversible one-electron redox processes and have been extensively utilized in aqueous organic flow batteries (AOFBs). However, the early variant, methyl viologen (MVi), exhibits low stability in aqueous electrolytes, restricting its practical implementation in AOFB technology. In this context, leveraging the tunability of organic molecules, various substituents have been incorporated into the viologen core to achieve better stability, lower redox potential, and improved solubility. In this work, we introduce bisphosphonate-substituted viologens as candidates for AOFBs. The bulkiness and negative charges of the bisphosphonate groups enhance the solubility and the electrostatic repulsion among viologen molecules, minimizing the bimolecular side reactions that lead to degradation. Additionally, the electron-donating effect of this new substituent significantly lowers the redox potential. As a result, the proposed viologen derivatives exhibit high solubility (1.66 - 1.81 M in water) and stability (capacity decay of 0.009%/cycle or 0.229%/day when tested at 0.5 M). These parameters are coupled with the lowest redox potentials exceeding all previously reported viologens utilized in AOFBs (-0.503 V and -0.550 V against SHE for mono- and bis-phosphonate viologen, respectively).

Local Structure Regulation for Oxygen Redox and Structure Stability of P2-Type Cathodes.

The local structure plays a crucial role in oxygen redox reactions, which boosts the capacity of layered oxide cathodes for sodium-ion batteries. While studies on local structural ordering have primarily focused on the intra-layer ordering, there has been limited research on the inter-layer stacking for the layered cathode materials for sodium-ion batteries. In this work, the impact of the intra-layer and inter-layer local structural regulation on anionic kinetics and the structure stability are explored through experimental analysis and theoretical calculations. Cu2+ substitution is introduced to adjust the transition metal inter-layer structure of P2-Na0.67Mg0.28Mn0.72O2, obtaining a zig-zag stacked honeycomb superlattice structure in P2- Na0.67Cu0.14Mg0.14Mn0.72O2. The local structure regulation mitigates the cation migration, improves the structure reversibility even at a deeply desodiation state of Na0.05, and the reductive coupling between cationic and anionic redox processes facilitates electron transfer from oxygen to copper ions and governs the properties of electrochemical kinetics and hysteresis. A full cell with hard carbon anode shows commendable energy density at high power density. This study paves an optional path for enhancing the structure stability and dynamics of oxygen redox chemistry in P2-type cathode materials for sodium-ion battery systems.

Unveiling the Contribution of Hydrogen Radicals to Per- and Polyfluoroalkyl Substances (PFASs) Defluorination: Applicability and Degradation Mechanisms.

At present, the defluorination of per- and polyfluoroalkyl substances (PFASs), including perfluoroether compounds as substitutes of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonate, is limited by the effective active species produced during the oxidation-reduction process. The contribution of the hydrogen radical (•H) as a companion active substance in the photoreduction and electrocatalytic degradation of PFASs has been neglected. Herein, we demonstrate that perfluorocarboxylic acids and perfluoroether compounds such as PFOA and hexafluoropropylene oxide dimer acid (GenX) underwent near-complete photodegradation and effective defluorination by continuously generating •H through perfluoroalkyl radical activation of water under UV irradiation without any reagents and catalysts. Importantly, the initial dissolved oxygen, H+, and impurities in surface water scarcely inhibited the defluorination of the PFASs. The difference in the defluorination mechanism between PFOA and GenX under the action of •H was elucidated by combining theoretical calculations with targeted and nontargeted analysis methods. The investigation of the photodegradation of different PFASs indicates that perfluoroether compounds were not easily photodegraded via reduction of •H compared with other compounds, whereas polyfluorinated compounds in which some F atoms were replaced with Cl were more prone to elimination. However, the UV/•H system was ineffective against perfluorosulfonic acids. This study provides an unprecedented perspective for further development of the removal technology of PFASs and the design of alternative PFASs that are easy to eliminate.

Beyond the Bench: Contextualizing the Impacts of Char Redox Properties on Biogeochemical Cycling and Microbial Ecosystem Services.

The electrochemical properties of chars have been recently described, positioning chars as active participants in microbial redox processes through functional groups, aromatic structures, redox-active metals, and radicals. While bench-scale studies have advanced mechanistic understanding of char's behavior and potential effects, translating these findings to complex ecosystems remains challenging. This is mainly due to the complexities of microbial communities and the unique properties of various ecosystems. Factors like char aging and patina formation, and environmental parameters including oxygen and moisture availability, pH, and organic matter content can significantly affect char electrochemical properties and microbial interactions. This highlights the need for a broader understanding of char redox processes to predict and effectively manage unintended environmental impacts or enhance beneficial effects. Long-term monitoring of complex systems amended with char is also needed to determine whether char accumulation has long-term redox effects on microbial ecosystem services, including biogeochemical cycling. Predictive understanding of these processes would inform the production of chars to enhance beneficial processes such as increased soil productivity, and provide new opportunities for engineered environmental remediation. Here, we summarize how char redox properties affect well-defined microbial systems and discuss key factors that determine whether the effects of char redox properties are enhanced or attenuated in complex systems. We also identify critical knowledge gaps about chars' role in microbial redox processes that are important for environmental sustainability and postulate that managing char's redox properties, such as electron donating, accepting, or conducting ability, is an emerging opportunity to influence microbial ecosystem services.

Enhancing Nutrient Digestibility and Antioxidant Efficacy in Piglets: The Impact of Fermented Rapeseed Meal Supplementation on Biochemical Parameters and Oxidative Stress Markers

Abstract This study aimed to investigate the effects of varying levels of dried fermented rapeseed meal (FRSM) on the nutrient digestibility and antioxidant efficacy in piglets. The experiment was conducted on 300 piglets, starting at 18 days of age. The primary experimental factor was the inclusion of FRSM in the diet, substituting mainly for post-extraction soybean meal and wheat. Two control groups were established: a positive control (PC) supplemented with 2500 ppm zinc oxide, and a negative control (NC) without additives. Additionally, four experimental groups were designated based on FRSM inclusion levels: FR-8 (8% FRSM), FR-12 (12% FRSM), FR-15 (15% FRSM), and FR-25 (25% FRSM). Results indicated a positive impact on nutrient absorption and redox processes, characterized by reduced efficiency of lipid peroxidation products such as malondialdehyde and lipid hydroperoxide in both blood and organs like the liver and intestines. From this perspective, the recommended inclusion of fermented rapeseed meal in piglet feed appears to be within the range of 8–12%

Combined 7Li NMR, density functional theory and operando synchrotron X-ray powder diffraction to investigate a structural evolution of cathode material LiFeV2O7.

In our recent study, we demonstrated using 7Li solid-state Nuclear Magnetic Resonance (ssNMR) and single-crystal X-ray diffraction that the cathode LiFeV2O7 possesses a defect associated with the positioning of vanadium atoms. We proposed that this defect could be the source of extra signals detected in the 7Li spectra. In this context, we now apply density functional theory (DFT) calculations to assign the experimental signals observed in 7Li NMR spectra of the pristine sample. The calculation results are in strong agreement with the experimental observations. DFT calculations are a useful tool to interpret the observed paramagnetic shifts and understand how the presence of disorder affects the spectra behavior through the spin-density transfer processes. Furthermore, we conducted a detailed study of the lithiated phase combining operando synchrotron powder X-ray diffraction (SPXRD) and DFT calculations. A noticeable volume expansion is observed through the first discharge cycle which likely contributes to the enhanced lithium dynamics in the bulk material, as supported by previously published ssNMR data. DFT calculations are used to model the lithiated phase and demonstrate that both iron and vanadium participate in the redox process. The unusual electronic structure of the V4+ exhibits a single electron on the 3dxy orbital perpendicular to the V-O-Li bond being a source of a negative Fermi contact shift observed in the 7Li NMR of the lithiated phase.

Magnetopyrite Fe1-xS modified with N/S-doped carbon as a synergistic electrocatalyst for lithium-sulfur batteries.

Rational design of effective cathode host materials is an effective way to solve the problems of serious shuttle and slow conversion of polysulfides in lithium-sulfur batteries (LSBs). However, the redox reaction of sulfur differs from conventional "Rocking chair" type batteries and involves a cumbersome phase transition process, so a single-component catalyst cannot consistently and steadily enhance the reaction rate throughout the redox process. In this work, a hybrid composed of magnetopyrite Fe1-xS catalyst-modified with N/S-doped porous carbon spheres (Fe1-xS@NSC) is proposed as a novel sulfur host to synergistically promote the adsorption and redox catalysis conversion of polysulfides. In this hybrid, the NSC skeleton provides excellent electrical conductivity and abundant adsorption sites for the physical immobilization of polysulfides; the magnetopyrite Fe1-xS nanoparticles promote the fast conversion reaction from Li2S2 to Li2S, affording strong adsorption and catalytic conversion. The optimal LSB with Fe1-xS@NSC manifests a high initial capacity of 971mAhg-1 at 0.2 C (1 C=1675mAhg-1) and a retention rate of up to 75% after 100 cycles. This work can provide a new approach for rationalizing the novel transition metal sulfide/porous carbon-based composite hosts with efficient lithium polysulfides (LiPSs) adsorption and catalytic conversion in high-performance lithium-sulfur batteries.

Physiological and transcriptome analysis of sex-specific responses to cadmium stress in poplars.

Soil cadmium (Cd) pollution is a serious ecological problem worldwide. Understanding Cd-detoxification mechanisms in woody plants will help to evaluate their tolerance ability and phytoremediation potential to Cd-polluted soils. This study investigated the growth, physiochemistry, Cd distribution, and transcriptome sequencing of male and female poplars under three Cd levels (0, 50, and 100 mg·kg-1). The results showed that Cd stress significantly inhibited the growth of aboveground parts. Over 70 % of the Cd was distributed in the cell wall fraction of roots, stems, and leaves, with the majority accumulating in the roots. Poplars can conjugate Cd with phytochelatins to reduce Cd damage, which is more evident in males than females. The antioxidant defense system of females is more effective than that of males at reducing the damage from Cd. Females demonstrated a stronger Cd-regulation ability than males under the 100 mg·kg-1 Cd treatment. Sex-specific responses to Cd were associated with differential gene expression. Under Cd stress, the genes related to oxidation-reduction processes, antioxidant enzyme activity and defense mechanisms, cell wall synthesis, and glutathione metabolism were mainly enriched and upregulated in females, whereas in males, genes related to photosynthesis and photosynthetic pigment biosynthesis were mainly enriched and downregulated, indicating greater damage to the photosynthetic system than in females. Our study provides novel insights into the mechanisms responding to Cd tolerance in poplars. Further studies should be carried out to assess the impact of soil Cd pollution on the wood quality of poplars.

A 3D four-fold interpenetrated conductive metal-organic framework for fast and robust sodium-ion storage.

Two-dimensional conductive metal-organic frameworks (2D c-MOFs) with high electrical conductivity and tunable structures hold significant promise for applications in metal-ion batteries. However, the construction of 3D interpenetrated c-MOFs for applications in metal-ion batteries is rarely reported. Herein, a 3D four-fold interpenetrated c-MOF (Cu-DBC) constructed by conjugated and contorted dibenzo[g,p]chrysene-2,3,6,7,10,11,14,15-octaol (DBC) ligands is explored as an advanced cathode material for sodium-ion batteries (SIBs) for the first time. Notably, the expanded conjugated and four-fold interpenetrating structure endows Cu-DBC with transmission channels for electrons and sufficient spacing for sodium ion diffusion. As expected, the Cu-DBC cathode showcases higher specific capacity (120.6 mA h g-1, 0.05 A g-1) and robust cycling stability (18.1% capacity fade after 4000 cycles, 2 A g-1). Impressively, the Cu-DBC cathode also exhibits good electrochemical properties at extreme temperatures (-20 °C and 50 °C). A series of in/ex situ characterizations and systematic theoretical calculations further reveal the sodium-ion storage mechanism of Cu-DBC, highlighting a three-electron redox process on the redox-active [CuO4] units. This work provides valuable insights for exploring and enriching the applications of 3D interpenetrated c-MOFs in metal-ion batteries.

Nitrite binding to myoglobin and hemoglobin: Reactivity and structural aspects.

Nitrite (NO2-) interacts with myoglobin (Mb) and hemoglobin (Hb) behaving as a ligand of both the ferrous (i.e., Mb(II) and Hb(II)) and ferric (i.e., Mb(III) and Hb(III)) forms. However, while the binding to the Fe(III) species corresponds to the formation of a stable complex (i.e., Mb(III)-NO2- and Hb(III)-NO2-), in the case of the ferrous forms the reaction proceeds with a nitrite reductase redox process, leading to the oxidation of the heme-protein with the reduction of NO2- to NO. This event is of the utmost importance for the rapid production of NO in vivo in the blood stream and in striated muscles, being crucial for the regulation of the blood flow, and thus for O2 supply to poorly oxygenated tissues, such as the eye's retina. Further, NO2- interacts with Mb(II)-O2 and Hb(II)-O2, inducing their oxidation with a complex mechanism, which has been only partially elucidated. Mb and Hb form the complex with NO2- through the O-nitrito binding mode (i.e., Fe-ONO-), which is regulated by residues paving the heme distal side; thus, in a site-directed mutant, where HisE7 is substituted by Val, the interaction occurs in the N-nitro binding mode (i.e., Fe-N(O)O-), like in most other heme-proteins. The structure-function relationships of the interaction of NO2- with both ferric and ferrous forms of Mb and Hb are discussed here.

Paddlewheel-type and half-paddlewheel-type diruthenium(II,II) complexes with 1,8-naphthyridine-2-carboxylate.

Paddlewheel-type diruthenium(II,II) complexes are paramagnetic with two unpaired electrons (S = 1) and can be utilized as versatile building blocks for higher-order structures, such as supramolecular complexes, coordination polymers, and metal-organic frameworks, although they are generally highly air-sensitive. In this study, we developed an air-stable paddlewheel-type diruthenium(II,II) complex with two electron-withdrawing 1,8-naphthyridine-2-carboxylate (npc) ligands, [Ru2(μ-npc)2(O2CMe)2] (1). The two acetate ligands in 1 can be replaced by other carboxylate ligands; the solvothermal reactions of 1 with benzoic acid (HO2CPh) yields the heteroleptic [Ru2(μ-npc)2(O2CPh)2] (2), whereas its reaction with 1,8-naphthyridine-2-carboxylic acid (Hnpc) produces the homoleptic [Ru2(μ-npc)2(η2-npc)2] (3). The molecular structures of 1-3 were characterized using paramagnetic 1H NMR, ESI-TOF-MS, elemental analyses, and single-crystal X-ray diffraction, which revealed that 1 and 2 form conventional paddlewheel-type structures, where two npc and two carboxylate ligands coordinate to the Ru2 core in a cis-2 : 2 arrangement, whereas 3 forms a half-paddlewheel-type structure, with the Ru2 core coordinated by two bridging μ-npc and two chelating η2-npc ligands. Temperature-dependent magnetic susceptibility measurements of 1-3 showed large zero-field splittings (D = 227, 238, and 240 cm-1, respectively) due to the Ru24+ center, and their effective magnetic moments at 300 K, ranging from 2.78 to 2.90μB, are consistent with the spin-only value of 2.83μB for an S = 1 system. Electrochemical analyses revealed that 1-3 are redox-active and undergo reversible redox processes; their cyclic voltammetry (CV) diagrams showed an oxidation wave associated with the Ru25+/Ru24+ process and two sequential reduction waves corresponding to the reduction of two npc ligands. Notably, 1-3 show intense broad absorption bands at approximately 500-800 nm, theoretically assigned to the metal-ligand charge transfers (MLCTs) from the d(Ru2) to π*(npc) orbitals.

Fast and low‐cost determination of prostate‐specific antigen using paper‐based immunodevice modified with Cu@CuS@Au NPs nanocages

AbstractIn this study, the authors designed a paper‐based electrochemical immunodevice modified with copper embedded in copper sulphide hollow nanocages wrapped with Au nanoparticles (Cu@CuS@Au NPs) for the specific detection of prostate‐specific antigen (PSA), aiming to advance point‐of‐care testing. The large specific surface area of Cu@CuS nanocages enables efficient capture of biotin antibodies, leading to the direct amplification of the signal through the inhibition of electron transport in the redox process of Cu, eliminating the need for universal redox electron mediators. Additionally, Au NPs on the surface of Cu@CuS can accelerate charge transfer and conjugate with anti‐PSA. The hierarchical morphology and structure of Cu@CuS nanocages were characterised using scanning electron microscopy and transmission electron microscopy. The fabrication process of the immunodevice was monitored using cyclic voltammetry and electrochemical impedance spectroscopy analyses. PSA was sensitively detected using differential pulse voltammetry on this proposed immunodevice within a linear range from 0 to 100 ng/ml (R2 = 0.996), achieving a low detection limit of 0.077 ng/ml. In addition, the practicality of the developed immunosensor has been proven by successfully detecting PSA in human serum samples obtained from clinical settings. The integration of electrochemical sensors and microfluidic devices holds promise for developing cost‐effective approaches in clinical immunoassays.

Nickel(II) complexes with covalently attached quinols rely on ligand-derived redox couples to catalyze superoxide dismutation.

Although nickel is found in the active sites of a class of superoxide dismutase (SOD), nickel complexes with non-peptidic ligands normally do not catalyze superoxide degradation, and none has displayed activity comparable to those of the best manganese-containing SOD mimics. Here, we find that nickel complexes with polydentate quinol-containing ligands can exhibit catalytic activity comparable to those of the most efficient manganese-containing SOD mimics. The nickel complexes retain a significant portion of their activity in phosphate buffer and under operando conditions and rely on ligand-centered redox processes for catalysis. Although nickel SODs are known to cycle through Ni(II) and Ni(III) species during catalysis, cryo-mass spectrometry studies indicate that the nickel atoms in our catalysts remain in the +2 oxidation state throughout SOD mimicry.

Microbially mediated iron redox processes for carbon and nitrogen removal from wastewater: Recent advances.

Iron is the most abundant redox-active metal on Earth. The microbially mediated iron redox processes, including dissimilatory iron reduction (DIR), ammonium oxidation coupled with Fe(III) reduction (Feammox), Fe(III) dependent anaerobic oxidation of methane (Fe(III)-AOM), nitrate-reducing Fe(II) oxidation (NDFO), and Fe(II) dependent dissimilatory nitrate reduction to ammonium (Fe(II)-DNRA), play important parts in carbon and nitrogen biogeochemical cycling globally. In this review, the reaction mechanisms, electron transfer pathways, functional microorganisms, and characteristics of these processes are summarized; the prospective applications for carbon and nitrogen removal from wastewater are reviewed and discussed; and the research gaps and future directions of these processes for the treatment of wastewater are also underlined. This review is expected to give new insights into the development of economic and environmentally friendly iron-based wastewater treatment procedures.

Оценка активности глутатионового звена антиоксидантной системы у беременных женщин коренного и пришлого населения Приамурья с экологических и этнических позиций

In order to study the state of the glutathione link of the antioxidant system (AOS) in pregnant women of the alien and indigenous population living in urban and rural areas, using the example of the Amur region, 175 patients were examined during their initial visit in the first and second trimesters and in the absence of iron deficiency states. Depending on their ethnicity and place of residence, the pregnant women were conditionally divided into 3 groups: urban aliens (Caucasians) (n=67); rural aliens (Caucasians) (n=74); rural indigenous people of the Amur region (Nanai), belonging to the Mongoloid race (n=34). Comparative characteristics of the indicators of women in groups 1 and 2 (urban and rural aliens) indicated environmental features of glutathione antioxidant protection (AOP) during pregnancy. Analysis of data from groups 2 and 3 (rural newcomers and natives) revealed ethnic peculiarities of the studied detoxification zone. Taking into account the participation of iron in the processes of free radical oxidation and antioxidant protection, the level of hemoglobin, serum ferritin in women was determined to exclude iron deficiency conditions, as well as the content of total glutathione, reduced (GSH) and oxidized (GSSG) forms in whole blood with the calculation of redox status (GSH/GSSG ratio) as a biomarker of AOS. Statistical data processing was performed using the programs "Microsoft Excel 2010", "Statsoft Statistica", version 6.1, 10.01. As a result of the studies, a reliable decrease in the content of total glutathione was found in urban patients of the newcomer population compared to rural newcomers due to a decrease in the reduced form both in the first and second trimesters with a multidirectional trend of the oxidized fraction in these groups, which showed the ecological orientation of the AOS functioning. Ethnic features in native women were revealed when comparing the parameters under study with newcomers living in similar rural areas, in the form of reliably low values of the reduced form of glutathione in the 2nd trimester of gestation, as well as a reliable decrease in the level of total and reduced glutathione in the 2nd trimester compared to the 1st. The optimal variant of the functional state of the glutathione link of the AOS was determined by the indicators of the oxidative stress level - the redox status in newcomer pregnant women of the village, based on its reliably high indicators in the 1st and 2nd trimesters compared to pregnant women of the native population of the village and especially with newcomers living in the city. The obtained data should be taken into account when carrying out therapeutic and preventive measures for complicated pregnancy, taking into account the ecological and ethnic features of oxidation-reduction processes. Key Words: pregnant women, newcomers, indigenous people, city, village, glutathione, ferritin

CONVERSION OF AQUEOUS AMMONIA SOLUTIONS USING AN ADAPTIVE WATER PURIFICATION SYSTEM

Water purification from ammonium nitrogen is currently an urgent task for protecting drinking water sources and ensuring the required water quality for consumers in various sectors of the Ukrainian economy. The technological approaches covered in this article can be used to remove other ammonium-based compounds from water. The obtained results of the adaptive water purification system (AWPS) with a simulated highly concentrated aqueous ammonium solution (1,16 g/dm3) suggest their use in water purification technologies from hydrobionts and side-products of biogas systems (digestat purification). Pulsed electrochemical methods were used in the operation of the AWPS in combination with ultrasonic exposure on oxidation-reduction processes with controlled injection of gas mixtures. A high correlation between all the variables studied was established. The same was confirmed by the regression analysis made in the process of empirical modeling of the relationship between the treatment time and the change in pH and in the concentrations of ammonium nitrogen, nitrates and nitrites. That is, all the indicators of multiple correlation and determination in the constructed significant models indicate a very high correlation with the treatment time. The decrease in pH from 11 to 9.6 can be explained by the fact that acids were formed during the treatment of the model solution, which caused the decrease. The energy efficiency of the AWPS operation was assessed by analyzing changes in the concentrations of the main component of the simulated solution (ammonium) and its derivatives using the example of nitrites and nitrates and a fixed operating time of 60 min. The use of electrolysis methods allowed the conversion of ammonium in an aqueous solution into derivatives - an aqueous solution of nitrites and nitrates, to record changes in their concentrations, and when using membrane electrolysis to obtain them in an ionic form, which is optimally suitable for plant nutrition and direct synthesis of nitrogen-containing fertilizers with simultaneous application by irrigation or spraying.