Kostiantyn Yaroshenko | National Academy of Sciences of Ukraine (original) (raw)

Papers by Kostiantyn Yaroshenko

Acque Sotterranee - Italian Journal of Groundwater, 2024

The paper discusses the possibility of using groundwater as a source of water supply... more The paper discusses the possibility of using groundwater as a source of water supply for Mykolaiv during emergencies or military operations. A hydrogeological model of the Mykolaiv groundwater field was developed to investigate the water exchange pattern and sources of operational groundwater reserves in the Upper Sarmatian aquifer, which is a primary source of drinking groundwater in the Mykolaiv area. The influence of various factors on water-bearing capacity of the Upper Sarmatian sediments was assessed, including the vulnerability of the fresh groundwater to the intrusion of brackish water from the Bug Estuary. The study also examined the feasibility of operating the aquifer under forced conditions, depending on the duration of emergency periods or military operations.

VІ Міжнародна конференція «Перспективи впровадження інновацій у атомну енергетику», 2024

На сьогодні існуючі технології переробки великих об'ємів трапних вод АЕС (десятки тисяч м3) в осн... more На сьогодні існуючі технології переробки великих об'ємів трапних вод АЕС (десятки тисяч м3) в основному пов’язані з послідовним застосуванням низки процесів: витримки в баках-резервуарах трапних вод, механічної фільтрації, коагуляції та іонного обміну на фільтрах з комбінованими функціями, випаровування трапних вод до кубового залишку. Оскільки більша частина низькоактивних трапних вод, що включають неорганізовані протічки першого контуру реактора в трап, рідини дезактивації обладнання, спецпралень та ін., мають відносно низький вміст солей (як правило, в межах до 7 г/дм3) і містять органічні сполуки (ЕДТА, щавлеву кислоту, поверхнево активні речовини), використання методів сумісного руйнування органічних сполук разом з ефективними сорбентами є перспективним з точки зору розробки нової технології дезактивації трапних вод.

Mineralogical Journal (Ukraine), 2024

The article presents the results of an experimental modelling of the influence of Са2+ ion concen... more The article presents the results of an experimental modelling of the influence of Са2+ ion concentration and pH of a model solution on the elemental composition and sorption capacity of natural (NB) and sodium-modified (SMB-20) bentonites from the Cherkasy deposit for 137Cs and 90Sr. The processes of the Cs and Sr sorption from multicomponent solutions with different pH, Eh and salt composition depend on the insoluble or sparingly soluble compounds precipitated on the bentonite surface. Based on the computer simulation data, it was found that small amounts of sediments, mainly oxides, hydroxides, Fe oxyhydroxides (hematite, goethite, limonite), and Ca carbonates (calcite, aragonite, dolomite) were present in the model solution with alkaline pH after adding CaCl2 solutions. Oxides and hydrated oxides of Fe, and calcium carbonates play an important role in the Cs and Sr sorption processes on bentonites. They can concurrently sorb radionuclides and block the sorption centres in montmorillonites. The concentration of the main structural elements (Si, Al) in the bentonites practically does not change with the increased pH and Ca2+ ion concentration in the model solution compared to the initial samples of NB and SMB-20, which indicates their structural stability. At the same time, an increase in the calcium concentration and a decrease in the sodium concentration were found in the ion-exchange complex of montmorillonite — the main bentonite mineral if compared to the initial samples. This can eventually lead to the transformation of SMB-20 bentonite from Na, Ca form to Ca, Na form. The 137Cs and 90Sr sorption on NB is shown to proceed more effectively, compared to SMB-20 in conditions of the increased pH and Ca2+ ion concentration. The results of this research may justify the bentonite clay application as a component of the isolating engineered barriers of radioactive waste disposal facilities.

Geologìčnij žurnal/Geologìčnij žurnal/Geological Journal (Ukraine), Jun 26, 2024

The data obtained and published to date by experts in various fields indicate that there are no a... more The data obtained and published to date by experts in various fields indicate that there are no absolutely harmful or absolutely beneficial trace elements, the only question is their concentration and speciation in natural waters (including groundwater). The forms of occurrence in natural waters are particularly important for elements that may have different degrees of oxidation (e.g., arsenic, manganese) or a high ability to form complexes with water anions (e.g., nickel). In addition, the possible positive and negative effects of biological exposure to drinking water that meets the quality criteria but has slightly elevated levels of trace elements (the so-called “chronic” effect) are currently being actively discussed. The aim of this study is to determine the speciation of biologically active trace elements in the waters of the Skifska area of the Nemyriv drinking water deposit in the Pivdennyi Buh River basin by geochemical modelling. The modelling was performed us-ing the PHREEQC software. Trace elements found in water in concentrations measured by analytical methods are considered in this paper. The data on the content of 7 elements (As, Mn, Sr, Ni, P, Si and F) in the water of 6 wells in the Skifska area (3 wells in the ravine and 3 wells along the Ustia River) were analysed. It was shown, that Sr, Ni, P and F in the water of the wells considered in the Nemyriv drinking water deposit do not exceed the MPC. The concentration of As exceeds the MPC. Mn concentrations in the wells located in the ravine do not exceed the MPC, but significant excesses are observed in the wells located along the Ustia River. Based on the mineral composition of the rocks, the results of geochemical modelling, and the different supply mechanisms of the wells located in the ravine and along the river, it can be concluded that the manganese is of anthropogenic origin . None of the water in the Skifska area under consideration meet the water quality requirements in terms of the total specific content of pollutants of the first and second hazard classes. The main reason for this discrepancy is the increased concentration of arsenic in the water. However, this is in the relatively safe form of As(V). Phosphorus and arsenic concentrations are largely determined by co-precipita-tion with iron minerals . Fluorine behaves like a classical halogen in the well water of the Skifska area and is in oxidation state-1, and the main source of fluorine is biotite and fluorite. Strontium and manganese in the well waters of the Skifska area of the Nemyriv deposit are in oxidation degree +2, mainly as Me2+ cations . The manganese occurrence in such a oxidation degree indicates its potential bioavailability, so it is necessary to carry out additional analytical studies to determine the concentrations of Mn and organic compounds, per-form repeated geochemical modelling, assess the danger of these waters for people and develop additional water treatment measures.

INUDECO 2024. ІХ Міжнародна конференція «Проблеми зняття з експлуатації об’єктів ядерної енергетики та відновлення навколишнього середовища», 2024

The report presents the results of an experimental modelling of the influence of Са2+ ion concent... more The report presents the results of an experimental modelling of the influence of Са2+ ion concentration and the alkaline pH of a model solution on the sorption capacity of natural (NB) and sodium-modified (SMB-20) bentonites from the Cherkasy deposit for 137Cs and 90Sr. Based on the computer simulation data, it was found that small amounts of sediments, mainly oxides, hydroxides, Fe oxyhydroxides (hematite, goethite, limonite), and Ca carbonates (calcite, aragonite) were present in the model solution with the increase in Са2+ ion concentration (after adding CaCl2 solution) and alkaline pH. The obtained Cs and Sr sorption values indicate that the insoluble / sparingly soluble compounds do not block the interlayer surface of montmorillonite (the main mineral of bentonite clays), but are formed mainly on the basal surface, frayed edges and surface defects of the mineral grains of montmorillonite. The concentration of the main structural elements (Si, Al) in the bentonites practically does not change with increased pH and Ca2+ ion concentration in the model solution compared to the initial samples. This fact indicates the stability of the bentonites under these conditions. At the
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same time, an increase in the calcium concentration and a decrease in the sodium concentration were found in the ion-exchange complex of the bentonites, if compared to the NB. This results in the transformation of SMB 20 bentonite from Na, Ca form to Ca, Na form. The Cs and Sr sorption on NB is shown to proceed more effectively than on SMB-20. The results of this research may justify the bentonite clay application as a component of the isolating engineered barriers of radioactive waste disposal facilities.

Geological Journal, 2024

The safety of near-surface and deep radioactive waste storage facilities is based on a system of ... more The safety of near-surface and deep radioactive waste storage facilities is based on a system of engineered and natural barriers. Significant degradation of the engineered barrier system composed of cemented waste matrixes covered by cement mixture, concrete compartments, and structures at the basement of the storage facility may cause radionuclide transfer from the facility to groundwater. Mixing of the cement and concrete with water leads to the formation of several various hydration products with subsequent leaching of Ca2+ ions and formation of hydroxyl ions (OH-), which affects the alkalinity of the water environment and the sorption properties of bentonite, as a component of the engineered barrier at the basement of near-surface facilities. The article presents the results of an experimental study of the influence of Ca2+ ion concentration and pH of the model solution (similar to groundwater composition at Vector Site in Chornobyl Exclusion Zone) on the elemental composition and sorption properties of natural (NB) and Na-modified (PBA-20) bentonites from the Cherkasy deposit concerning 137Cs at the Solid : Solution ratio of 1 : 100. Geochemical modeling suggests that addition of CaCl2 to test solution and resulting alkaline pH leads to precipitation of solids, mainly oxides, hydroxides, Fe oxyhydroxides (hematite, goethite, limonite), and Ca carbonates (calcite, aragonite, dolomite). Their role in Cs adsorption was evaluated. The concentration of structural elements (Si, Al) in bentonites practically does not change with Ca2+ ion concentration increase in the model solution, demonstrating the bentonite structure’s stability under these conditions. At the same time, an increase in the Ca concentration and a decrease in the Na concentration was found in the ion exchange complex of the bentonites if compared to the initial natural bentonite. This results in the transformation of Na-modified bentonite from Na, Ca-form to Ca, Na-form. The total sorption capacity of NB and PBA-20 bentonite concerning Cs+ ions at increased concentrations of Ca2+ ions and pH of the solution slightly decreases, though retaining high values of the degree of absorption (> 90 %). The total adsorption of Cs+ ions on NB and PBA-20 bentonites from model groundwater with the addition of CaCl2 from 16 to 960 mg/dm3 and increase of рН from 7.4 to 11.8 decreases with the increase in ionic strength, in particular, due to competition with Са2+ and Na+ ions. NB and PBA-20 bentonites of the Cherkasy deposit remain a reliable component of the liner at the repository basement owing to their main functional property – high absorption capacity for 137Cs, which is an important dose-forming radionuclide of short-lived low- and medium-level waste.

XI наук.-практ. конф. "Мінеральні-сировинні багатства України: шляхи оптимального використання", Хорошів, 2023

The information available in geological funds on the chemical composition of groundwater in the N... more The information available in geological funds on the chemical composition of groundwater in the Nikopol region was collected and analyzed. The results showed that the chemical composition of most waters is not suitable as drinking waters, only one third of the samples meet the quality standards of the State Sanitary and Epidemiological Sanitary and Epidemiological Standard.

Mineralogical Journal (Ukraine), 2023

Natural zeolites are abundant and inexpensive resources. They are crystalline hydrated aluminosil... more Natural zeolites are abundant and inexpensive resources. They are crystalline hydrated aluminosilicates with a framework structure that has pores and channels occupied by water, alkali, and alkaline earth cations. Having high
cation exchange capacity, acting as a molecular sieve, natural zeolites have been widely utilized in recent decades as adsorbents in separation and purification processes. Modification of natural zeolite increases its adsorption capacity of environmental pollutants, in particular, radionuclides from low-level liquid radioactive waste. The article presents results obtained from a study of the chemical composition of the structural elements and ion exchange complexes of natural, acid-modified and alkali-modified zeolites from the Sokyrnytske deposit. The main rock-forming mineral of the Sokyrnytsky zeolite is clinoptilolite. The zeolite was modified by a 5.5 M HCl solution for 2 hours at 100 oC using a backflow condenser. The ratio of solid to liquid phases was 1 : 2. For alkaline modification, 1.4 M NaOH solution was used. The exposure time was 2.75 hours. The conditions and phase ratio were similar to those in acidity modification. Based on the composition of the ion exchange complex, natural zeolite belongs to potassiumcalcium-
sodium (K > Ca > Na) clinoptilolites. In the process of acidity and alkaline modification of the natural zeolite, the exchangeable cations and the content of structural cations in the clinoptilolite lattice become redistributed. In alkaline-modified zeolite, the content of exchangeable cations Na and Ca increases, and the content of K and structural cations Al decreases. In acid-modified zeolite, the number of exchangeable cations Na, Mg, Ca, K decreases. At the same time, the content of Fe and Al decreases and the relative amount of Si in the lattice increases. The Si/Al ratio increases in the following succession: natural zeolite → alkali-modified zeolite → acid- odified zeolite. The specific surface area of the modified zeolites increases compared to the natural ones. The largest increase is observed for the acid-modified zeolite. The textural characteristics and mineral composition of the studied samples indicate that the natural, acid-modified and alkali-modified zeolites from the Sokyrnytske deposit may be used for removal of radionuclides from low-level liquid radioactive waste.

XVII International Scientific Conference “Monitoring of Geological Processes and Ecological Condition of the Environment”, 2023

The article reads about sorption properties of bentonites from the Cherkasy deposit towards 90Sr ... more The article reads about sorption properties of bentonites from the Cherkasy deposit towards 90Sr in case of degradation of cement-concrete components of engineered barrier system in near-surface radioactive waste storage facilities. Was determined the regularities of the impact of pH and Ca2+ ion concentration in model groundwater of the Chornobyl Exclusion Zone on the transformation and sorption properties of bentonites towards 90Sr. The contact with degraded cement structures of the near-surface repository causes decrease of the sorption properties of bentonite towards strontium. The degree of Sr adsorption is higher for natural Ca-bentonite than for Na-modified bentonite. Natural bentonite will more reliably isolate Sr within the radioactive waste storage facilities ensuring safety for humans and the natural environment.

XVII International Scientific Conference “Monitoring of Geological Processes and Ecological Condition of the Environment”, 2023

The paper focuses on the identification of hydrogeochemical processes in groundwater within the z... more The paper focuses on the identification of hydrogeochemical processes in groundwater within the zone of influence of the Safonivske uranium deposit using the balance method and the determination of water types with the help of the Piper diagram. A total of 70 datasets on the chemical composition of water from the alluvial, aeolian-deluvial, Sarmatian, Pliocene and Kharkiv aquifers were considered. The average composition of groundwater was compared with the drinking water standards. For most wells, the water was found to be of a mixed type, but in some cases chloride and sulphate water was observed. Another characteristic feature is the balance between the following pairs of ions: sum of (Na + + K +) and Cl-; sum of (Mg 2+ + Ca 2+) and sum of (SO4 2-+ HCO3-); Ca 2+ and Mg 2+. However, in some cases, direct ionic exchange between sodium and potassium, between calcium and magnesium is most likely to occur. According to drinking water standards, most of the groundwater within the zone of influence of the Safonivske uranium deposit is not suitable for human consumption without preliminary treatment.

Proceedings of the NTUU “Igor Sikorsky KPI”. Series: Chemical engineering, ecology and resource saving, 2021

The lack of scientifically substantiated requirements, comprehensively developed and approved in ... more The lack of scientifically substantiated requirements, comprehensively developed and approved in a prescribed manner, for the usage of clays as a barrier material poses risks for the safe disposal of radioactive waste in facilities at the ‘Vector’ site for the period of their operation and closure. The bentonite clay from Ukraine’s largest Cherkasy deposit of bentonite and palygorskite clays is considered the most durable as the main component of the insulating (underlying) screens of radioactive waste disposal facilities. The main properties and compositional features of the Cherkasy natural bentonite clay (Dashukovskaya site, layer II) and its variety such as alkaline earth bentonite (activated soda bentonite), which provide isolation of radioactive waste in disposal, are considered. It is shown that the Cherkasy field has good waterproofing and barrier properties, including a high sorption capacity with respect to 90Sr and 137Cs, which is one of the main characteristics that ensu...

Матеріали міжнародної науково-практиченої конференції "Екологія. Людина. Суспільство", 2021

Проведено дослідження фазового та хімічного складу продуктів озонування модельних розчинів – іміт... more Проведено дослідження фазового та хімічного складу продуктів озонування модельних розчинів – імітаторів трапних вод АЕС з реакторами ВВЕР. Визначення фазового складу отриманих зразків проводили методом рентгенофазового аналізу. Ідентифікацію мінерального складу проводили відповідно до картотеки ASTM Powder diffraction file 2003. PDF-2, Database, Sef.1-89. Дослідження морфології зразків і їх елементного складу проводили методом скануючої електронної мікроскопії (СЕМ) і електронно-дисперсійної спектроскопії (ЕДС) на растровому електронному мікроскопі Tescan Mira 3 LMU, обладнаному енергодисперсійним модулем для мікроаналізу. В процесі озонування модельного розчину – імітатора трапної води, проходить руйнування органічних комплексів та утворення твердої фази, в складі якої фіксуються 60Co,54Mn і 55Fe. За даними РФА, складові осаду характеризуються нанометровими розмірами частинок та значним вмістом аморфної складової. Головними ферумовмісними фазами визначено оксигідроксиди феруму – ле...

Nuclear Power and the Environment, 2021

The main feature of bentonite clays is their highsorption capacity with respect to various radion... more The main feature of bentonite clays is their highsorption capacity with respect to various radionuclides.The study of sorption kinetics of 137Cs was performed inthe static mode by natural and industrial soda modified(PBA‑20) samples of bentonite clays of Cherkasy depositof bentonite and paligorskite clays from groundwatermodel solutions of radioactive waste disposal facilitiesof “Vector” production complex under various pH andsolution mineralisation. The desorption of occludedsamples was studied in distilled water and acetate-ammoniumbuffer solution. The value of the degree ofsorption (S) for 137Cs on the modified samples exceeds90 %, for natural bentonite this indicator is lower (about83–85 %). On both types of bentonite with increasing timeof their contact with aqueous solution and pH, there is aredistribution of water-soluble,ion-exchange and fixedforms of radionuclide and the share of the latter, that is notparticipating in migration processes increases, indicatingthe ability of bentonites to immobilize effectively for along time. It is shown that Na-modified bentonite hashigher proportion of sorption in fixed form compared tonatural one and its application increases the probabilityof irreversible fixation of migrating radionuclides undernon-optimal conditions of sorption (high pH (>11) ofwater after prolonged contact with cement-concretecomponents of engineering barriers) and thus increasesthe environmental safety of the storage facility. It isshown that bentonite clays of the Cherkasy deposit canserve as an effective material for creating anti-migrationbarriers of I and II stages of surface/near-surface storagefacilities for radioactive waste disposal at the “Vector” production complex. At the same time, the issue of practical application of bentonite clays of Cherkasy deposit for accurate predictions of securing radioactive waste disposal of Chornobyl origin requires further study of sorption-desorption properties of bentonite clay with respect to other fission products and actinides.

Geochemistry of Thechnogenesis, 2021

The article is devoted to the study of the barrier properties of bentonite clays from the Cherkas... more The article is devoted to the study of the barrier properties of bentonite clays from the Cherkasy deposit (Ukraine) as the most promising material forengineered barriers in near-surface disposal facilities for low-level radioactive waste.The work presents a description of the Cherkasy bentonite deposit, in particular, of the most promising II layer of the Dashukivka site, and thecomposition and properties of the natural and soda-modified (PBA20) bentonites which can be used for safe long-term storage and disposal ofradioactive waste. The scanning electron microscope (SEM) images of the samples were made and the chemical and mineral composition of thesamples was determined. Based on the obtained data, the Dashukivka bentonite was classified as Al-Fe-montmorillonit. The main rock-formingminerals of the bentonite are montmorillonite (75 ± 3 wt. %) and quartz (20 - 25 wt. %). Infrared spectra of the bentonites in the range of 4000 - 400 cm-1 are typical for dioctahedral Al-smectites and are almost identical both for the natural and modified samples. The derivatographic analysis (DTA) of the bentonite samples allows us to conclude that the modified bentonite PBA-20 has greater thermal stability than the natural bentonite. Thetotal weight loss of the samples is about 10.3% and 17.8%, respectively. From the experimental study of 137Cs adsorption from a simulated ChEZ water solution (mineralization – 0.2 g/dm3 ), it was found that the equilibrium in the sorbent-solution system is established within 12 to 14 h, and thedegree of adsorption on the modified bentonite PBA-20 reaches 93%. The degree of adsorption on the natural bentonite is 7 - 10% lower. Analysis ofthe partition coefficients (Kd) also indicates a higher efficiency of the Na-modified bentonite compared to the natural, and that ion exchange is themain mechanism of caesium adsorption. Increasing of the pH of the initial solution results only in a slight increase of the degree of adsorption. Thedegree of 137Cs adsorption on Na-modified bentonite is practically independent of the initial concentration of Ca2+ (from 16 to 160 mg/dm3 ) and Na+ (from 6 to 60 mg/dm3 ) in the solution. However, 137 Cs adsorption on natural bentonite decreases with the increase in Na+ concentration. Thus, thebentonite clays from the Cherkasy deposit (Dashukivka site, II layer) having good barrier properties can be recommend as anti-migration engineeredbarriers for radioactive waste repositories, in particular, near-surface storage facilities I and II line of Vector complex.

Геологічна наука в незалежній Україні , 2021

During the ozonation process of model simulators-solutions of trap waters of NPPs equipped with W... more During the ozonation process of model simulators-solutions of trap waters of NPPs equipped with WWER, nanoparticles of lepidocrocite and goethite with an admixture of ferrispinel and a significant content of amorphous component are formed as a part of the mineral sediment. The percentage of components can be traced to a number: Mn> Fe> Co> Sr> Na> Mg, that agrees with the stability constants of EDTA chelate complexes. During the ozonation process, c(Mn2+) decreases by 94.3%, (Co2+) - by 6%, 137Cs activity decreases by 26%, and 90Sr - by 15.7%.

Геологічна наука в незалежній Україні, 2021

In article shown results the chemical, mineral and granulometric composition of natural and modif... more In article shown results the chemical, mineral and granulometric composition of natural and modified by soda bentonite clays from Cherkas’ke deposit, the composition of exchange cations, diffractograms, differential heating curves, IR spectra and features of 137Cs sorption. It is determined that sorption degree for 137Cs on the modified samples exceeds 90%, for natural bentonite – about 85%. On both types of bentonite with increasing of contact time with model solution and pH, there is a redistribution of water-soluble, ion-exchange and fixed forms of radionuclides and the part of the latter that do not participate in migration processes increases, which indicates the ability of bentonites to effectively immobilize radionuclides for a long time. Investigated bentonite clays can serve as material for creating anti-migration barriers for surface/subsurface storage facilities for RW disposal.

XIV International Scientific Conference “Monitoring of Geological Processes and Ecological Condition of the Environment”, 2020

This article is devoted to the analysis of experience in using thermodynamic modeling to solve pr... more This article is devoted to the analysis of experience in using thermodynamic modeling to solve problems related to safe disposal of radioactive waste in Ukraine. It is shown that a number of approaches and models have been developed in Ukraine (models of solid solutions for clay and cement, sorption models, chamber model, etc.), which can be used both to assess the efficiency of EBS components and to assess the geochemical evolution of the geological environment. The possibility of thermodynamic modeling using to take into account physical and chemical interactions in the safety analysis of RAW repositories is also illustrated and the place of this approach in the justification of safety of RW disposal shown is.

Ядерна енергетика та довкілля, 2020

Вибір і впровадження ефективної й екологічно безпечної технології очищення рідких радіоактивних в... more Вибір і впровадження ефективної й екологічно безпечної технології очищення рідких радіоактивних відходів (РРВ) українських АЕС є актуальним, оскільки діючана АЕС схема переробки РРВ має чимало суттєвих недоліків. Однією з таких технологій вважається сорбційно-осадова з використанням природних або модифіко-ваних мінеральних сорбентів, зокрема цеолітів, які мають молекулярно-ситові та сорбційно-селективні властивості до низки радіонуклідів. У статті наведено результати дослідження сорбції 90Sr і 137Cs природним, кислотно- та лужно-модифікованим цеолітами Сокирницького родовища з модельних розчинів РРВ та визначено форми знаходження сорбованих радіонуклідів. Основним мінералом у складі цеолітових порід є кліноптилоліт — 70 ± 3 мас. % із домішками кварцу та слюди у кількостях ~12 та ≤ 3 % відповідно. Показано, що в процесі модифікації цеоліту відбувається перерозподіл обмінних катіонів і вмісту катіонів у ґратці кліноптилоліту. Природний цеоліт належить до калій-кальцій-натрієвих кліноптилолітів, натрій модифікований цеоліт — натрій-калій-кальцієвих, а кислотно модифікований — калій-натрій-кальцієвих. Відношення Si/Al збільшується у ряду: цеоліт природний → цеоліт натріймодифікований→ цеоліт кислотно-модифікований. Установлено, що модифікація кліноптилоліту натрієм не лише підвищує температурну стійкість, але й збільшує адсорбцію радіонуклідів 90Sr і 137Cs з модельних розчинів РРВ. Ізотерми іонного обміну показують, що селективність натрієвої форми кліноптилоліту щодо досліджуваних радіонуклідів є вищою, ніж селективність природного і кислотно-модифіко-ваного кліноптилолітів. Максимальний ступінь сорбції 90Sr природним цеолітом протягом експерименту (14 діб) становить 55 %, 137Cs — 90 %, лужно-модифікованим для 90Sr — 62,2 %, а 137Cs — 98,78 %, кислотно-модифікованим 90Sr — 18 %, а 137Cs — 85 %. Аналіз отриманих результатів дає підстави рекомендувати цеоліт Сокирницького родовища і його натрієві форми як ефективні сорбенти радіонуклідів із РРВ у разі запровадження сорбційно-осадової технології.

Ядерна енергетика та довкілля, 2020

Наведено результати дослідження умов окиснення озоном органічних компонентів рідких радіоактивних... more Наведено результати дослідження умов окиснення озоном органічних компонентів рідких радіоактивних відходів (РРВ) на прикладі модельного розчину з імітованими розчинами щавлевої кислоти та динатрієвої солі етилендиамінтетраоцтової кислоти (ЕДТА). Установлено, що в процесі обробки органічних складових РРВ
озоном відбувається зменшення величини рН, що призводить до зниження ефективності їхньої деструкції. Утримання рН на рівні вихідних значень (11−12 одиниць) шляхом постійного підлуговування здатне підвищити ефективність деструкції органічних компонентів РРВ на 30 %. ЕДТА краще піддається деструкції озоном (озонолізу), ніж щавлева кислота. Деструкція органічних компонентів РРВ відбувається в два етапи: перший, більш швидкий, та другий, більш повільний. Максимальний ступінь деструкції ЕДТА в умовах експерименту становив 86 %, ступінь деструкції щавлевої кислоти — 51 %, максимальний ступінь деструкції органічних компонентів модельного розчину РРВ (ЕДТА, щавлева кислота, синтетичні поверхнево-активні
речовини) становив 67 %. За рахунок співосадження та адсорбції під час озонування розчину відбувається зменшення концентрації марганцю в модельному розчині РРВ на 94,3 %, знижується активність 137Cs на 26 %, а 90Sr на 15,7 %, концентрація кобальту зменшується лише на 6 %.

Thesis Chapters by Kostiantyn Yaroshenko

The dissertation is submitted to the degree of Doctor of Philosophy in Technical Sciences by spat... more The dissertation is submitted to the degree of Doctor of Philosophy in Technical Sciences by spatiality 21.06.01 – Ecological Safety. State Ecological Academy of Postgraduate Education and Management, Kyiv, 2021.
The dissertation is devoted to the study of the ecological safety of processes of removing radionuclides from multicomponent solutions. It is established that in the process of the destruction of organic substances – components of liquid radioactive waste (LRW) by ozone, a significant drop in pH value takes place as a result of a decrease in the destruction efficiency, and the process of the destruction of organic components occurs in two stages: fast and slow. It is determined that the highest efficiency of the destruction of organic components of LRW is achieved with constant alkalization of the solution and keeping the pH values at 11-12 units. It is shown that in the process of ozonation, precipitates of metal hydroxides and oxides are formed, on the surface of which radionuclides are fixed due to co-precipitation and adsorption. Thus, in the result of ozonation, the concentration of Mn2+ decreases by 94.3%, Co2+ – by 6%, the activity of 137Cs reduces by 26%, 90Sr – by 15.7%. It is found that in all parameters (degree of sorption, rate of establishment of sorption equilibrium, the prevalence of strongly fixed forms of sorption – acid-soluble and residual) Na-modified sorbents are the most effective among the studied sorbents: relative to 90Sr, Co2+, Mn2+ – Na-modified bentonite of the Cherkas’ke deposit PBA-20 (maximum sorption degree of 90Sr – 85%, Co2+ – 99%, Mn2+ – 99%); relative to 137Cs – an alkali-modified zeolite of the Sokyrnyts’ke deposit (the degree of 137Cs sorption – 99%). I.e. industrial modification of bentonites with soda and laboratory modification of zeolite with alkali (NaOH), significantly increases the degree of sorption of the studied radionuclides in comparison with their natural Ca-forms. It is determined that the sorption equilibrium upon adsorption of Co, Mn, Cs from the model LRW is established within from one to seven days, Sr – from two to fourteen days, the degree of sorption is practically independent of the initial pH of the solution, and the sorbents have a high buffering capacity. It is determined that it is more appropriate to use an alkali-modified zeolite as a sorbent under dynamic conditions. It is found that zeolites are characterized by high selectivity for 137Cs concerning its chemical analogue – 40К. It is shown that preliminary ozonation of the solution for 2 hours effectively destroys the organic components of LRW in such a way that the degree of sorption of the studied radionuclides is only 2 - 3% lower from the solution after ozonation in comparison with the control solution, which did not contain organic components. The adequacy parameters (MAPE, MPE, R2, R2adj, χ2, F, BIC, AIC) of mathematical models are calculated, and it is determined that the sorption model of the kinetics of complex chemical processes of all studied radionuclides (Co, Mn, Cs, Sr) with the most effective sorbents (PBA-20 bentonite and alkali-modified zeolite) is the most adequate and a universal model among those presented. Recommendations on the development of a scheme for LRW treatment by extracting radionuclides are presented, a conceptual block diagram of LRW treatment is given.

Acque Sotterranee - Italian Journal of Groundwater, 2024

VІ Міжнародна конференція «Перспективи впровадження інновацій у атомну енергетику», 2024

Mineralogical Journal (Ukraine), 2024

Geologìčnij žurnal/Geologìčnij žurnal/Geological Journal (Ukraine), Jun 26, 2024

Geological Journal, 2024

XI наук.-практ. конф. "Мінеральні-сировинні багатства України: шляхи оптимального використання", Хорошів, 2023

Mineralogical Journal (Ukraine), 2023

XVII International Scientific Conference “Monitoring of Geological Processes and Ecological Condition of the Environment”, 2023

Proceedings of the NTUU “Igor Sikorsky KPI”. Series: Chemical engineering, ecology and resource saving, 2021

Матеріали міжнародної науково-практиченої конференції "Екологія. Людина. Суспільство", 2021

Nuclear Power and the Environment, 2021

Geochemistry of Thechnogenesis, 2021

Геологічна наука в незалежній Україні , 2021

Геологічна наука в незалежній Україні, 2021

XIV International Scientific Conference “Monitoring of Geological Processes and Ecological Condition of the Environment”, 2020

Ядерна енергетика та довкілля, 2020

ІІ Міжнародна науково-практична конференція "Геохімія техногенезу: виклики ХХІ століття", 2024

Безпека приповерхневих сховищ радіоактивних відходів ґрунтується на системі інженерних і природни... more Безпека приповерхневих сховищ радіоактивних відходів ґрунтується на системі інженерних і природних бар’єрів. Значна деградація інженерної бар'єрної системи, що складається з цементованих матриць відходів, покритих цементною сумішшю, бетонних відсіків і конструкцій у підвалі сховища, може спричинити перенесення радіонуклідів зі сховища з інфільтрацією в ґрунтові води. Змішування цементу і бетону з водою призводить до утворення низки різних продуктів гідратації з подальшим вилуговуванням іонів Са2+ і утворенням гідроксильних іонів (OH-), що впливає на лужність водного середовища і сорбційні властивості бентонітів, як компонентів протиміграційного бар’єру в основі приповерхневих сховищ. Тому доцільним є експериментальне дослідження впливу концентрації іонів Са2+ та величини рН модельного розчину (аналогічного складу підземних вод майданчика «Вектор» у Чорнобильській зоні відчуження) на елементний склад і сорбційні властивості природного (ПБ) і Na-модифікованого (ПБА-20) бентонітів Черкаського родовища (використовуються в якості одного з елементів інженерних бар’єрів) щодо 137Cs та 90Sr. Метою роботи було вивчити закономірності впливу величини рН розчину та різних концентрацій іонів Са2+ в модельних розчинах ґрунтових вод Чорнобильської зони відчуження на хімічний склад і сорбційні властивості бентонітів Черкаського родовища щодо 137Cs та 90Sr.

Перспективи впровадження інновацій у атомну енергетику, 2021

Нині в Україні накопичено десятки тисяч метрів кубічних рідких радіоактивних відходів (РРВ), які ... more Нині в Україні накопичено десятки тисяч метрів кубічних рідких радіоактивних відходів (РРВ), які зберігаються у сховищах тимчасового типу, що є значною проблемою екологічної безпеки. Сорбційно-осадова схема вилучення радіонуклідів для переробки трапних вод АЕС є перспективною. На основних етапах дезактивації трапних вод доцільно використовувати дешеві та доступні природні та модифіковані сорбенти–алюмосилікати: бентоніти та цеоліти. Для використання сорбційно-осадового методу вилучення доцільно провести руйнування органічних компонентів трапних вод (ЕДТА, щавлева кислота, СПАР) озоном, оскільки наявність даних речовин ускладнюють сорбційне вилучення 60Со і 54Мn.