ИСПОЛЬЗОВАНИЕ АВТОМАТИЗИРОВАННОЙ ТЕХНОЛОГИИ ДЛЯ РАСЧЁТОВ ХАРАКТЕРИСТИК КАЧЕСТВА СТОКА ПО ДАННЫМ ГИДРОХИМИЧЕСКИХ И ГИДРОЛОГИЧЕСКИХ НАБЛЮДЕНИЙ

To calculate the characteristics of river water flow quality, the FSBI "SHI" developed an automated software package that allows for joint processing of regime hydro chemical and hydrological information. The objective of this work is to present the capabilities of the program in obtaining characteristics of water flow quality using the example of the Luga River according to data from 2000 to 2017. The first characteristic of the flow quality is the proportion of volumes contaminated with single chemical components (Vpoll). With the use of an automated software package, the annual and long-term values of Vpoll of the Luga river runoff for each polluting component were calculated and their probabilistic estimates were given. It is shown that the upper limit of Vpoll% values for water saturation with O2 is below the norm, for the content of Mn2+, Cu2+, N-NO2, Fetot and COD was 100%; for the content of Pb2+ and oil products ‒ 64-79%, for the content of O2 ‒ 39% and for other components did not exceed 16.5%. Trends in the change in annual values of Vpoll for all pollutants were calculated. The second characteristic of runoff quality is the proportion of its partial volumes contaminated with aggregates of chemical components, and assessed by classes and categories in accordance with RD 52.24.643-2002. The most polluted was the water runoff in 2006 and 2010. It is assigned to the 4th grade, category "a" and is characterized as dirty.Для расчётов характеристик качества стока воды рек в ФГБУ «ГГИ» был разработан автоматизированный программный комплекс, позволяющий проводить совместную обработку режимной гидрохимической и гидрологической информации. Задачей настоящей работы является представление возможностей программы в получении характеристик качества стока воды на примере реки Луга по данным 2000–2017 гг. Первой характеристикой качества стока воды является доля объёмов, загрязнённых единичными химическими компонентами (Vзаг%). С применением автоматизированного программного комплекса рассчитаны годовые и многолетние значения Vзаг% стока воды реки Луга для каждого загрязняющего вещества и даны их вероятностные оценки. Показано, что верхний предел значений Vзаг% для насыщения воды O2 ниже нормы, для содержания Mn2+, Cu2+, N-NO2‑, Feобщ и ХПК составил 100%; для содержания Рb2+ и нефтепродуктов – 64-79%, для содержания O2 – 39% и для остальных компонентов не превысил 16,5%. Рассчитаны тенденции изменения годовых значений Vзаг% для всех загрязняющих веществ. Второй характеристикой качества стока воды является доля его частичных объёмов, загрязнённых совокупностями химических компонентов, и оценённая по классам и разрядам в соответствии с РД 52.24.643-2002. Показано, что наиболее загрязнённым был сток воды в 2006 и 2010 годах. Он отнесён к 4-му классу, разряд "а" и охарактеризован как грязный. Слабо загрязнённым 2-го класса сток воды реки Луга был только в 2016 и 2017 годах. В остальные годы он являлся загрязнённым 3-го класса, разряд "а" либо разряд "б". Все результаты расчётов представлены в программном комплексе, как в табличной форме, так и в графическом виде. ЛитератураКараушев А.В., Скакальский Б.Г. Актуальные проблемы исследования качества поверхностных вод // Метеорология и гидрология. 1973. № 10. С. 73-81.Караушев А.В., Скакальский Б.Г. Проблемы мониторинга качества поверхностных вод суши // Проблемы современной гидрологии: сборник статей. Л.: Гидрометеоиздат, 1979. С. 94-105.Методические основы оценки и регламентирования антропогенного влияния на качество поверхностных вод / Под ред. А.В. Караушева. Л.: Гидрометеоиздат, 1987. 288 с.Румянцева Э.А., Бобровицкая Н.Н. Методика интегральной оценки многолетних изменений качества речного стока на примере р. Ворскла // Метеорология и гидрология. 2012. №5. С. 85-95.Румянцева Э.А., Бобровицкая Н.Н., Ильин Е.В. Новый подход к автоматизированному расчёту частичных объёмов речного стока разной степени загрязнения (на примере р. Селенга) // Метеорология и гидрология. 2014. №6. С. 51-60.Румянцева Э.А., Бобровицкая Н.Н. Загрязненный сток трансграничных рек на Юго-Востоке Украины, как индикатор угрозы экологической безопасности Ростовской области Российской Федерации при разработке на Украине сланцевого газа // Международные аспекты водного законодательства / Под общ. ред. Г.А. Карлова. М.: Издание Государственной Думы, 2015. С.46-52.Румянцева Э.А., Бобровицкая Н.Н., Сухоногова Е.С. Единая оценка количества и качества водного стока реки Сейм с помощью новой автоматизированной технологии // Гидросфера. Опасные процессы и явления. 2020.Т.2. Вып. 1. С. 53-70.Румянцева Э.А., Бобровицкая Н.Н. Характеристика качества стока рек России, трансграничных с Беларусью, Украиной и Казахстаном, и его связь с бассейновыми геосистемами // Гидросфера. Опасные процессы и явления. 2020. Т. 2. Вып. 2. С. 173-195. DOI: 10.34753/HS.2020.2.2.173.Скакальский Б.Г. Оценка качества речных вод // Методы расчёта речного стока: Международные высшие гидрологические курсы ЮНЕСКО при МГУ: в 2 частях. Часть 1. М.: изд. МГУ (МКГК ЮНЕСКО), 1980. С. 98-112.Смыжова Е.С. Оценка стока биогенных веществ с учётом особенностей гидрохимической информации: Автореф. дисс. … канд. геогр. наук. СПб., 2010. 27 с.Шелутко В.А., Колесникова Е.В, Смыжова Е.С. Вопросы оценки качества поверхностных вод по гидрохимическим данным // Материалы V Международной конференции «Экологические и гидрометеорологические проблемы больших городов и промышленных зон» (г. Санкт-Петербург, 7-9 июля 2010 г.). СПб.: Крисмас+, 2010. С. 30-39

Crystalline WO3 nanoparticles for No2 sensing

This study shows excellent NO2-sensing properties of tungsten oxide nanoparticles, prepared using a facile procedure which includes dissolution of metallic tungsten in hydrogen peroxide with subsequent low-temperature (400 °C) heating. We also conducted a thorough literature survey on sensor properties of tungsten oxide prepared by various means and found that the sensor response towards NO2 registered in this work achieved the highest level. The most intriguing feature of the material obtained was a highly reproducible sensor signal at room temperature which was more than 100 times higher than any reported previously for WO3. The probable reason for such high sensor response was the presence of two WO3 polymorphs (-WO3 and h-WO3) in the material synthesized using a peroxide-assisted route. In order to further investigate synthesizedWO3 materials, sophisticated experimental (XRD, SEM, TEM, BET) and theoretical (B3LYP, HSE) methods have been used, as well as resistance and sensor response measurements at various temperatures

Obituary for Prof. Dr. Alexander Gaskov

Professor Alexander Gaskov, our dear colleague, friend and teacher, passed away on January 18, 2021 from COVID-19 [...]

Obituary for Prof. Dr. Alexander Gaskov

Professor Alexander Gaskov, our dear colleague, friend and teacher, passed away on January 18, 2021 from COVID-19 [...

Au Functionalized SnS₂ Nanosheets Based Chemiresistive NO₂ Sensors

Layered Au/SnS2 nanosheet based chemiresistive-type sensors were successfully prepared by using an in situ chemical reduction method followed by the hydrothermal treatment. SEM and XRD were used to study the microscopic morphology and crystal lattice structure of the synthesis of Au/SnS2 nanomaterials. TEM and XPS characterization were further carried out to verify the formation of the Schottky barrier between SnS2 nanosheets and Au nanoparticles. The as-fabricated Au/SnS2 nanosheet based sensor demonstrated excellent sensing properties to low-concentrations of NO2, and the response of the sensor to 4 ppm NO2 at 120 °C was approximately 3.94, which was 65% higher than that of the pristine SnS2 (2.39)-based sensor. Moreover, compared to that (220 s/520 s) of the pristine SnS2-based sensor, the response/recovery time of the Au/SnS2-based one was significantly improved, reducing to 42 s/127 s, respectively. The sensor presents a favorable long-term stability with a deviation in the response of less than 4% for 40 days, and a brilliant selectivity to several possible interferents such as NH3, acetone, toluene, benzene, methanol, ethanol, and formaldehyde. The Schottky barrier that formed at the interface between the SnS2 nanosheets and Au nanoparticles modulated the conducting channel of the nanocomposites. The “catalysis effect” and “spillover effect” of noble metals jointly improved the sensitivity of the sensor and effectively decreased the response/recovery time

Au Functionalized SnS2 Nanosheets Based Chemiresistive NO2 Sensors

Layered Au/SnS2 nanosheet based chemiresistive-type sensors were successfully prepared by using an in situ chemical reduction method followed by the hydrothermal treatment. SEM and XRD were used to study the microscopic morphology and crystal lattice structure of the synthesis of Au/SnS2 nanomaterials. TEM and XPS characterization were further carried out to verify the formation of the Schottky barrier between SnS2 nanosheets and Au nanoparticles. The as-fabricated Au/SnS2 nanosheet based sensor demonstrated excellent sensing properties to low-concentrations of NO2, and the response of the sensor to 4 ppm NO2 at 120 °C was approximately 3.94, which was 65% higher than that of the pristine SnS2 (2.39)-based sensor. Moreover, compared to that (220 s/520 s) of the pristine SnS2-based sensor, the response/recovery time of the Au/SnS2-based one was significantly improved, reducing to 42 s/127 s, respectively. The sensor presents a favorable long-term stability with a deviation in the response of less than 4% for 40 days, and a brilliant selectivity to several possible interferents such as NH3, acetone, toluene, benzene, methanol, ethanol, and formaldehyde. The Schottky barrier that formed at the interface between the SnS2 nanosheets and Au nanoparticles modulated the conducting channel of the nanocomposites. The “catalysis effect” and “spillover effect” of noble metals jointly improved the sensitivity of the sensor and effectively decreased the response/recovery time

Active Sites on Nanocrystalline Tin Dioxide Surface: Effect of Palladium and Ruthenium Oxides Clusters

Active sites of nanocrystalline tin dioxide materials with variable particle size, surface area, and catalytic modifiers were studied. Effect of palladium and ruthenium oxides clusters on the activity and concentration of tin dioxide surface centers was evaluated by temperature-programmed desorption techniques using probe molecules, FTIR spectroscopy, EPR, and thermogravimetric methods. The surface site concentration decrease was observed with an increase of SnO₂ particle size and BET area decrease. The active sites of SnO₂ were found to be selectively promoted by the additives. Accumulation of surface OH groups including hydroxyl spin centers and Broensted acid sites was characteristic for SnO₂/PdO_<i>x</i> nanocomposites as a result of water chemisorption enhancement due to proposed electronic clusters–support interaction. Ruthenium oxide was shown to increase the concentration of chemisorbed oxygen species via oxygen spillover route

Active Sites on Nanocrystalline Tin Dioxide Surface: Effect of Palladium and Ruthenium Oxides Clusters

Active sites of nanocrystalline tin dioxide materials with variable particle size, surface area, and catalytic modifiers were studied. Effect of palladium and ruthenium oxides clusters on the activity and concentration of tin dioxide surface centers was evaluated by temperature-programmed desorption techniques using probe molecules, FTIR spectroscopy, EPR, and thermogravimetric methods. The surface site concentration decrease was observed with an increase of SnO₂ particle size and BET area decrease. The active sites of SnO₂ were found to be selectively promoted by the additives. Accumulation of surface OH groups including hydroxyl spin centers and Broensted acid sites was characteristic for SnO₂/PdO_<i>x</i> nanocomposites as a result of water chemisorption enhancement due to proposed electronic clusters–support interaction. Ruthenium oxide was shown to increase the concentration of chemisorbed oxygen species via oxygen spillover route