The antimicrobial activity of silver and zinc exchanged cations in Y-zeolite (Ag/CBV-600, Zn/CBV-600) is evaluated against Staphylococcus aureus (gram (+)) and Escherichia coli (gram (-)) bacteria along with their adsorption capacity for viruses: brome mosaic virus (BMV), cowpea chlorotic mottle virus (CCMV), and the bacteriophage MS2. The physicochemical properties of synthesized nanomaterials are characterized by inductively coupled plasma optical emission spectroscopy (ICP-OES), UV-Vis spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM). According to the obtained results, the main species associated with the exchanged ions are Ag⁺ and Zn²⁺ cations with the concentration of around 1 atomic %. The incorporation of cations does not modify the Y-zeolite framework. The Ag/CBV-600 and Zn/CBV-600 materials show an inactivation of 90% for both gram (+) and gram (-) bacteria at 16 h at a relatively low concentration of nanomaterial (0.5 mg/mL). Moreover, the samples present good adsorption capacity for BMV, CCMV, and MS2 viruses showing adsorption higher than 40% after 2 h of interaction with the viruses. These prominent results allow the further usage of nanomaterials as an effective remedy to inhibit and reduce the spread of viruses such as SARS-CoV-2 or other gram (+) or gram (-) bacteria.

The limited access to fresh water and the increased presence of emergent pollutants (EPs) in wastewater has increased the interest in developing strategies for wastewater remediation, including photocatalysis. Graphitic carbon nitride (g-C₃N₄) is a 2D non-metal material with outstanding properties, such as a 2.7 eV bandgap and physicochemical stability, making it a promising photocatalyst. This work reports the process of obtaining high-surface-area (SA) g-C₃N₄ using the thermal-exfoliation process and the posterior effect of Ag-nanoparticle loading over the exfoliated g-C₃N₄ surface. The photocatalytic activity of samples was evaluated through methylene blue (MB) degradation under visible-light radiation and correlated to its physical properties obtained by XRD, TEM, BET, and UV–Vis analyses. Moreover, 74% MB degradation was achieved by exfoliated g-C₃N₄ compared to its bulk counterpart (55%) in 180 min. Moreover, better photocatalytic performances (94% MB remotion) were registered at low Ag loading, with 5 wt.% as the optimal value. Such an improvement is attributed to the synergetic effect produced by a higher SA and the role of Ag nanoparticles in preventing charge-recombination processes. Based on the results, this work provides a simple and efficient methodology to obtain Ag/g-C₃N₄ photocatalysts with enhanced photocatalytic performance that is adequate for water remediation under sunlight conditions.

In the present work, PdRu@mSiO₂ bimetallic core‐shell nanoreactors (NRs) are synthesized for the first time by a fine‐tuning one‐pot method. The obtained NRs are evaluated in the reduction of nitroarenes using 4‐nitrophenol (4‐NP), 1‐chloro‐4‐nitrobenzene (1‐Cl‐4‐NB), 4‐nitrotoluene (4‐NT) and 2,4‐dinitrophenol (2,4‐DNP) as reagents. The mesoporous PdRu@mSiO₂ NRs with a Pd1:Ru1 molar ratio present a homogenous spherical morphology with a single nucleus per capsule. Various techniques confirm the formation of Pd‐Ru alloy. The bimetallic NRs show higher catalytic activity and stability compared with the reference catalysts (free and supported nanoparticles (NPs)) and with those reported in the literature. The order of catalytic activity for studied nitroarene compounds is 4‐NP>1‐Cl‐4‐NB>2,4‐DNP>4‐NT. The catalytic activity of NRs is affected by inter and intramolecular interactions between the reagent molecules. The one‐pot method of NRs synthesis is low‐cost and effective, with possible application in the catalytic reduction of various hazardous materials.

Herein, the catalytic reduction of isomers of nitrophenols (NPS) using Ni _x Cu _y nanostructures with different molar ratios is presented. Ni _x Cu _y catalysts are prepared using star-shaped Ni nanoparticles as seeds. The applied synthesis transforms Ni nanoparticles into sheet-like structures when Cu species are deposited on them. The bimetallic sheet-like Ni _x Cu _y nanostructures demonstrate high catalytic activity to reduce NP isomers concerning their monometallic counterparts. The contribution of the Cu⁺ species affects the catalytic reduction of the NPS isomers. For example, the catalytic reduction of 4-nitrophenol (4-NP) depends on the Ni:Cu molar ratio: Ni_1.75Cu > Cu > NiCu > Ni₇Cu > Ni_3.5Cu > Ni. The Ni₇Cu catalyst exhibits the highest catalytic activity in the reduction of nitrophenol isomers 2-nitrophenol (2-NP) and 3-nitrophenol (3-NP), and the obtained results are comparable with those reported for noble-metal-based catalysts. The low-cost production of Ni _x Cu _y catalysts and their high catalytic stability and availability make them attractive for industrial applications.

The aim of the study. To assess the potential of geophysical methods to investigate the structure and properties of chernozemic soils. Location and time of the study. The field work was carried out during June-October 2018 on the two arable soils, namely Luvic Greyzemic Chernozem (Siltic) and Haplic Phaeozem (Siltic, Colluvic, Pachic) over Haplic Phaeozem (Siltic, Luvic), in the Bugotak Hills, which is part of the Cis-Salair denudation-accumulation plain on the right side of the Ob River in the south-east of West Siberia. Methodology. Soils were studied by the standard soil and agrochemical techniques as well as by such geophysical methods as magnetometry, electrotomography and ground-penetrating radar. Soil morphology was described, and soil samples were collected from soil genetic horizons. Physical, physicochemical and chemical (altogether up to 28) properties, pertaining to soil potential and actual fertility were determined. Relationships between soil properties and geophysical parameters were studied using correlation and multiple regression analyses. Main results. The study showed that when underlying solid rock is rather close to the surface, the magnetometry cannot be used to solve urgent issues in soil science. When soil total carbon (STC) in humus-accumulating layer was high, the relationship of the decrease in electrical resistivity (ER) with the increase in STC did not work anymore. The ER was found to depend on soil texture, as the heavier soil granulomety resulted in decreased ER. This regularity allows establishing the depth of illuvial horizons in humus-accumulating soils and a fortiori texture-differentiated ones. The ER in the humus-accumulation layer of the Luvic Greyzemic Chernozem (Siltic) was estimated as 70 ohm·m, while the 0-10 cm thick soil layer after subsurface cultivator could be determined by the ER values decreased to 40-45 ohm·m. The combined use of electrotomography and ground-penetrating radar was found to be the most promising for soil studies as such combination allows estimating the thickness of the humus-accumulating layer and its lower boundary, as well as discriminating between agro-dark-humus (arable) and dark-humus horizons, establishing the depth of the illuvial horizon and the upper boundary of the carbonate horizon. Conclusion. We believe that geophysical methods can be beneficial for soil genesis research and large-scale soil mapping because of their ability to account for natural heterogeneity of spatial variation of soil potential fertility properties. Large scale soil maps provide a fortiori indispensable basis to solve many agricultural and environmental problems such as monitoring soil properties’ changes because of soil degradation due to erosion, estimating pollution degree, assessing soil nutrients’ content and calculating fertilization rates, etc. Establishing even empirical relationships between soil geophysical parameters and crop yields currently seems to be a rather ambitious task, as crop yields are mostly determined not by “basic’ soil characteristics (which may correlate with geophysical parameters), but by plant available mineral nutrients and such external factors as photosynthetically active solar radiation, precipitation, fertilizer and pesticide application. Цель исследования: Оценка возможности применения геофизических методов при исследовании строения и свойств почв черноземного ряда. Место и время проведения. Полевые исследования выполнены в период июнь – октябрь 2018 г. на пахотных почвах (агрочернозем и агростратозем) Буготакского мелкосопочника, который является частью Предсалаирской денудационно-аккумулятивной равнины, расположенной в юго-восточной части Западной Сибири в правобережной части бассейна реки Оби. Методология. Изучение почв проводили общепринятыми в почвенно-агрохимических исследованиях методами, а также геофизическими методами, включающими магнитометрию, электротомографию и георадиолокацию. Почвенные исследования включали морфологическое описание строения почв, отбор образцов по генетическим горизонтам, анализ физических, физико-химических и химических свойств почв (до 28 показателей), характеризующих потенциальное и эффективное плодородие. Поиск зависимостей между почвенными параметрами и результатами геофизических исследований, а также между отдельными свойствами почв выполняли с помощью стандартных методов математической статистики (корреляция, регрессия). Основные результаты. В условиях близкозалегающих коренных пород применение магниторазведки для решения актуальных для почвоведения задач не представляется возможным. При высоких значениях содержания общего углерода в гумусово-аккумулятивном слое изученных почв закономерность снижения удельного...

The aim of the study was to assess changes in soil properties and agrochemical status under different land use (undisturbed, abandoned and agricultural) in the forest-steppe of West Siberia. Location and time of the study. Soil samples (27 in total) was performed in tge Iskitim district (Novosibisrk region, Russia) in summer 2020 from the soil pits along the entire profiles rom soil genetic horizons at three sites: (US) undisturbed meadow steppe with legumes, herbs and grasses (54,668˚ NL, 83,125˚ EL); (PS) agricultural site with ploughed soil, at the time of sampling under barley, oats and vetch mixture(54,668˚ NL, 83,125˚ EL); (AS) dry stepped meadow of grasses and herbs that had been abandoned for 27 years prior to sampling (54,666˚ NL, 83,098˚ EL). Site US soil was classified as clay illuvial shallow chernozem, site PS soil was classified as dark clay illuvial shallow agrozem, whereas AS soil was identified as clay illuvial postagrogenic shallow agrochernozem (according to the Russian classification). According to the IUSS Working Group WRB classification, US and AS soils were Luvic Greyzemic Chernozem (Siltic), whereas PS had Luvic Greyzemic Chernozem (Siltic, Aric). Methods. Soils were analyzed for organic ans carbonate carbon content, total and nitrite nitrogen, mobile phosphorus content, exchangeable calcium, as well as exchangeable and unexchangeable potassium and magnesium. Soil pH was measured potentiometrically. Soil granulometry was estimated by pipette technique after dispersion in sodium pyrophosphate. Main results. The presence of sod (horizon AUrz) and powdery grains of biogenic structure of the humus horizon are the main features of the undisturbed chernozem. The grainy soil structure was destroyed by ploughing, and, consequently, could not be found in the agrozem. Restoration of these features is important indicator of the postagrogenic transformation. As compared with the US soil, the AS one showed lower humus and total nitrogen content and stocks, especially in the ploughed horizon, but the difference was not statistically significant. These soil properties were found to be increased after 27 years of postagrogenic spontaneous restoration at the AS site. According to the studied soil properties, the agrochemical status of the studied undisturbed, abandoned and ploughed soil can be described as favorable for plant growth and crop production. Conclusions. The studied chernozems of the forest-steppe in West Siberia (undisturbed, ploughed and abandoned sites showed differences in their profile and surface horizon structure, carbonate layer location, the contents of mobile phosphorus, exchangeable magnesium. The topsoil (0–5 cm) at the undisturbed and abandoned sites accumulates biogenic elements (organic carbon, total and nitrate nitrogen, easily mobile phosphorus and exchangeable potassium. The absence of the difference in soil properties between the three studied site proves chernozem to be rather resistant to agrogenic influence. The site that had been abandoned for almost three decades, can be once again put int agricultural use. It should be emphasized that in Siberia the crop yields, especially grains, on chernozems are produced mainly by soil resources of mobile microelements without compensation their removal by fertilization. The agrogenic transformation rate and degree of Siberian chernozems are higher as compared with the European part of Russia. Therefore, we recommend monitoring agrochernoems fertility, especially after abandoned land are put once again in the agricultural use.