Kateryna Stepova

Dr. Kateryna Stepova

Environmental Safety, Lviv State University of Life Safety, Lviv, L’vivs’ka Oblast’, Ukraine
orcid

Research Focus & Metrics

Academic Career Length

18Years (2009-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
31 January 2009 in Applied Clay Science
Verified
Journal Article
Closed access
KSKateryna Stepova
Kateryna Stepova
DMDuncan J. Maquarrie
Duncan J. Maquarrie
IKIhor M. Krip
Ihor M. Krip

20 May 2023 in Water
Verified
Journal Article
Open access
PDF file
KSKateryna Stepova
Kateryna Stepova
IFIryna Fediv
Iryna Fediv
AMAušra Mažeikienė
Aušra Mažeikienė
JŠJulita Šarko
Julita Šarko
JMJonas Mažeika
Jonas Mažeika
The research focuses on ammonia and phosphate removal from wastewater by using a novel metal and microwave-treated clinoptilolite. For increasing adsorption capacity, the samples were calcinated or microwave irradiated in the solutions of Fe(III), Cu (II), or Ca(II) chlorides. BET-specific surface area measurement revealed that the calcination led to a decrease from 18.254 to 11.658 m2/g. The adsorption results were fitted to theoretical models. The PO43− adsorption in all samples as well as NH4+ adsorption in natural and Fe- and Ca-modified samples is best described using the Langmuir–Freundlich model, but in calcinated and Cu-modified clinoptilolite the NH4+ sorption is better characterized by the Freundlich model. The PO43− adsorption in natural and all modified samples is best described using the Langmuir–Freundlich model. Fe-modified and calcinated clinoptilolite showed the highest NH4+ adsorption capacity of 4.375 and 2.879 mg/g. Ca-modified samples demonstrated the lowest adsorption capacity of 0.875 mg NH4+/g. The metal-modified samples exhibit a significantly higher phosphate sorption capacity (from 800.62 for Cu-sample to 813.14 mg/g for the Fe-modified sample) than natural (280.86 mg/g) or calcinated samples (713.568 mg/g). Experimental studies in dynamic conditions revealed high NH4+ and sufficient PO43− ions captured on modified clinoptilolite. This study provides a feasible approach for the synchronous removal of the main eutrophication agents for implementation in additional (tertiary) wastewater treatment facilities.

27 March 2018 in International Journal of Polymer Science
Verified
Journal Article
Open access
PDF file
UKUlyana Khromiak
Ulyana Khromiak
VLVolodymyr Levytskyi
Volodymyr Levytskyi
KSKateryna Stepova
Kateryna Stepova
ATAndry Tarnawsky
Andry Tarnawsky
Kinetics of emulsion polymerization of hydrophilic vinyl monomers in the presence of polyvinylpyrrolidone and technological principles of their synthesis are determined. Reasonable technological parameters in the synthesis of copolymers are determined. Physicochemical properties of the synthesized copolymers (surface tension, the size of latex particles, and pH) are determined. Synthesized graft copolymers were used to create high-adhesion polymer-monomer compositions. These compositions have high reactivity at room temperature. It can be regulated by the nature of the polymer matrix and the introduction of comonomers and fillers due to the influence of physicochemical factors on the process of polymer formation. The rate of polymerization and the degree of monomer conversion largely depend on the nature of the polymer matrix. The highest polymerization rate and the maximum degree of conversion are observed when using a copolymer of polyvinylpyrrolidone and polymethylmethacrylate. Materials based on the developed compositions are characterized by a low residual monomer content and high operational properties, such as surface hardness, Vicat softening temperature, and adhesive bond strength to supports of different nature.

15 April 2020 in Series of Geology and Technical Sciences
Verified
Journal Article
Closed access
PBPavlo Bosak
Pavlo Bosak
VPVasyl Popovych
Vasyl Popovych
KSKateryna Stepova
Kateryna Stepova
RDRoman Dudyn
Roman Dudyn

12 April 2024 in Water
Verified
Journal Article
Open access
PDF file
TJTomas Januševičius
Tomas Januševičius
AMAušra Mažeikienė
Aušra Mažeikienė
KSKateryna Stepova
Kateryna Stepova
VDVaidotas Danila
Vaidotas Danila
DPDainius Paliulis
Dainius Paliulis
This scientific study investigated the adsorption capabilities of biochar samples derived from municipal sewage sludge pellets. Sewage sludge was pyrolyzed at various temperatures (400, 500, and 600 °C), and the biochar’s properties, including specific surface area, pore volume, and pore size distribution, were assessed. The results indicate that the sewage sludge biochar samples are mesoporous materials with significant potential for good adsorption performance. Despite showing a decrease in specific surface area compared to that achieved with pyrolysis at 400 °C, samples pyrolyzed at 600 °C demonstrated an increase in mesopore surface area, enhancing their adsorption potential. Two filtration experiments, conducted at a flow rate of 8 mL/min, revealed that the column containing sewage sludge pyrolyzed at 600 °C retained phosphorus the most effectively during the first and second experiments (with retention efficiencies of 87% and 78%, respectively). The study concludes that municipal sewage sludge biochar could be a promising material for the removal of phosphorus from wastewater and represents a viable solution for sustainable environmental development.

10 December 2018 in MATEC Web of Conferences
Verified
Journal Article
Open access
VPVasyl Popovych
Vasyl Popovych
KSKateryna Stepova
Kateryna Stepova
OPOleksandr Prydatko
Oleksandr Prydatko
Novoyavorivsk is located near large sulfur deposits in a transborder with Poland. The existing sanitation system in Novoyavorivsk is imperfect. Municipal wastes are stored in cloughs, ravines, river valleys. This causes an environmental hazard, as polluted wastewater is discharged to the water bodies. The aim of the work is environmental hazard assessment of Novoyavorivsk landfill. The tasks of the research are as follows: determination of chlorides and sulfates content in the landfill edaphotopes; measurement of power of equivalent dose of photon radiation. Determination of chlorides and sulfates was carried out by quantitative and qualitative methods. The equivalent dose of photon radiation was measured by dosimeter by SOEKS USA, LLC. In different sites of the landfill chlorides and sulfates content differs. The most polluted areas are at the distance of 10 m and 50 m from the foot. At a distance of 100 m from the landfill, the concentration of chlorides reduces to 0.001% (5 cm) and 0.1% (10 cm and 20 cm). High sulfate content is observed at 10 m from the foot of the landfill (1% in the 10 cm and 20 cm horizons). The power of the equivalent dose at a height of 10 m from the south side exceeds the pollution standard of 0.3 μSv/h and equals 0.32 μSv/h.