Urszula Klekotka

The widespread release of emerging and recalcitrant pollutants into the environment necessitates robust removal technologies. Advanced oxidation processes (AOPs) are known for degrading such pollutants, and sodium percarbonate (SPC) emerges as an alternative to liquid H₂O₂, generating both non-selective hydroxyl (•OH) and carbonate (CO₃^•−) radicals that are selective toward electron-rich moieties through physical energy inputs (UV, ultrasound, and cavitation) or transition metal/composite catalysts. This review examines recent literature on SPC-based AOPs, organized by pollutant category across water, soil, sludge, and sewer environments. A recurring finding is that SPC’s performance, including which reactive oxygen species predominates and the extent of true carbon mineralization, depends strongly on the specific activation strategy, pollutant, and matrix. Beyond pollutant degradation, SPC supports environmental and resource sustainability through functional applications, including greenhouse and odour gas suppression (CH₄, H₂S) in sewer deposits, enhanced sludge dewatering, and volatile fatty acid recovery. However, claims regarding SPC’s sustainability should be qualified against energy demand, catalyst synthesis, residual metal leaching, and under-characterised transformation-product ecotoxicity. By consolidating these findings, this review clarifies SPC’s demonstrated potential and defines the research directions that will support its translation toward real-world remediation, including pilot-scale validation, techno-economic analysis, and long-term catalyst and by-product management.

The objective of the present study was to evaluate the impact of high-density polyethylene (HDPE) used in two particle sizes (40 and 125 µm) on selected biochemical parameters in two species of green algae: Chlorella vulgaris and Scenedesmus quadricauda. Exposure to microplastics resulted in decreased cell numbers (up to 43%) and reductions in protein (up to 42%), monosaccharide, and chlorophyll contents in both algal species. Oxidative stress, as reflected by increased hydrogen peroxide levels (up to 120%) and enhanced lipid peroxidation, was observed in HDPE-treated cells. This was accompanied by elevated antioxidant enzyme activity, changes in ascorbate and proline content, and alterations in carotenoid composition. Thus, toxicity of HDPE and the induction of defense mechanisms involved in adaptation to environmental pollutants were confirmed in both microalgae. Changes in the physicochemical properties of the tested polymer surface were investigated using Fourier-Transform Infrared Spectroscopy, scanning electron microscopy (SEM), and porosimetry analysis. The presence of biofilm, hydroxyl groups, higher total pore volume, and maximum pore width on the surface of the microplastic confirmed that green algae may be responsible for the first step in HDPE structure modifications. Understanding the interactions between such micropollutants and green algae, key primary producers in aquatic food webs, is therefore essential.

A significant driving force in nanotechnology development is the environmentally friendly synthesis of nanomaterials using natural extracts as reducing and stabilizing agents. In this study, silver and copper nanoparticles were synthesized and compared using two approaches: (1) a green synthesis pathway employing beetroot extract as a natural bio-reductant and stabilizer, and (2) a conventional chemical reduction method. The resulting nanoparticles were extensively characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD), UV-Vis spectroscopy, and dynamic light scattering (DLS). The study revealed that the green synthesis route produced nanoparticles with well-defined morphology, high stability, and strong antimicrobial potential, outperforming those obtained via conventional chemical synthesis. Copper nanoparticles synthesized using beetroot extract exhibited particularly enhanced fungicidal and bactericidal properties, demonstrating the effectiveness of plant-based reducing agents in producing functional nanostructures. To further evaluate potential applications, the green-synthesized nanoparticles were incorporated into a polypropylene matrix, confirming their integrity and activity within the composite system. This work emphasizes the role of green synthesis in designing high-performance nanomaterials and highlights the promising capabilities of beetroot extract as a sustainable and efficient reducing and stabilizing medium for silver and copper nanoparticle production.

Nanoparticles based on gallium ferrite are explored as potential agents for magnetic fluid hyperthermia due to their magnetic performance and biocompatibility. In this study, Ga_xFe_3−xO₄ systems (0 ≤ x ≤ 1) were synthesized by co-precipitation of iron chlorides, with part of the series modified by a chitosan shell. Structural analysis confirmed single-phase formation across the studied range, while microscopy revealed irregular morphology, broad size distribution, and aggregation into mass-fractal-like assemblies. Chitosan was observed to coat groups of particles rather than single crystallites. Under an alternating magnetic field, all samples exhibited efficient heating, with specific absorption rate values generally increasing with gallium content. The composition Ga_0.73Fe_2.27O₄ showed the highest SAR—83.4 ± 2.2 W/g at 2.8 mg/mL, 532 kHz, 15.3 kA/m, and SAR values rose with decreasing concentration. Cytotoxicity assays without magnetic activation indicated no harmful effect, while chitosan-coated nanoparticles enhanced fibroblast viability and lowered metabolic activity of HeLa cells. Higher Ga content (x = 0.66) combined with chitosan modification was identified as optimal for hyperthermia. The results demonstrate the biomedical potential of these nanoparticles, while emphasizing the need to reduce shape heterogeneity, aggregation, and sedimentation for improved performance.

The hereby work presents the iron-nickel alloys electroplated on the different metallic substrates (aluminium, silver, brass) using galvanostatic deposition, with and without presence of the external magnetic field (EMF). The films were obtained in the same electrochemical bath composition - mixture of iron and nickel sulphates (without presence of additives) in the molar ratio of 2 : 1 (Ni : Fe), the electric current density (50.0 mA/cm ² ), and the time (3600 s). The mutual alignment of the electric (E) and magnetic field (B) was changeable - parallel and perpendicular. The source of EMF was a set of two permanent magnets (magnetic field strength ranged from 80 mT to 400 mT). It was analysed the surface microstructure, composition, morphology, thickness and the mechanical properties (roughness, work of adhesion). The surface morphology and the thickness of films were observed by Scanning Electron Microscopy (SEM) and Confocal Laser Scanning Microscopy (CLSM). The elemental composition of all FeNi films was measured using Wavelength Dispersive X-Ray Fluorescence (WDXRF). The crystalographic analysis of the deposits was carried out by X-Ray Diffraction. Depending on the used substrate, modified external magnetic field orientation influenced the tribological and physio-chemical properties of the deposited layers. The diamagnetic substrates and EMF application reduced the FeNi thickness and the average crystallites size, in contrast to the paramagnetic substrate. Parallel EMF increased the value of the tribological parameters for CuZn and Ag but decreased for Al. The content of FeNi structure was rising in the case of diamagnetic substrate and the dependence was opposite on the paramagnetic substrate.

A new biosensor based on the “surface plasmon resonance imaging (SPRi)” detection technique for the quantification of “fibroblast growth factor 23 (FGF23)” has been developed. FGF23 is mainly produced in bone tissues as a phosphaturic hormone that forms a trimeric complex with “fibroblast growth factor receptor 1 (FGFR1)” and αKlotho upon secretion. FGF23 stimulates phosphate excretion and inhibits the formation of active vitamin D in the kidneys. FGF23 has been shown to play a role in bone carcinogenesis and metastasis. The newly developed method, based on the array SPRi biosensor, was validated—the precision, accuracy, and selectivity were acceptable, and yielded less than ±10% recovery. The rectilinear response of the biosensor ranges from 1 to 75 pg/mL. The limit of detection was 0.033 pg/mL, and the limit of quantification was 0.107 pg/mL. The biosensor was used to determine FGF23 concentrations in the blood plasma of healthy subjects and patients with “clear cell” renal cell carcinoma (ccRCC). The obtained results were compared with those measured through an “enzyme-linked immunosorbent assay (ELISA)”. The determined Pearson correlation coefficients were 0.994 and 0.989, demonstrating that the newly developed biosensor can be used as a competitive method for the ELISA.

Magnetite and gallium substituted cuboferrites with a composition of Ga_xFe_3−xO₄ (0 ≤ x ≤ 1.4) were fabricated by thermal decomposition from acetylacetonate salts. The effect of Ga³⁺ cation substitution on the structural and thermomagnetic behavior of 4–12 nm sized core-shell particles was explored by X-ray and neutron diffraction, small angle neutron scattering, transmission electron microscopy, Mössbauer spectroscopy, and calorimetric measurements. Superparamagnetic (SPM) behavior and thermal capacity against increasing gallium concentration in nanoferrites were revealed. The highest heat capacity typical for Fe₃O₄@Ga_0.6Fe_2.4O₄ and Ga_0.6Fe_2.4O₄@Fe₃O₄ is accompanied by a slight stimulation of fibroblast culture growth and inhibition of HeLa cell growth. The observed effect is concentration dependent in the range of 0.01–0.1 mg/mL and particles of Ga_0.6Fe_2.4O₄@Fe₃O₄ design have a greater effect on cells. Observed magnetic heat properties, as well as interactions with tumor and healthy cells, provide a basis for further biomedical research to use the proposed nanoparticle systems in cancer thermotherapy (magnetic hyperthermia).

A new biosensor based on Surface Plasmon Resonance Imaging detection technique for quantitative determination of Fibroblast Growth Factor-23 has been developed. The FGF-23 is mainly produced in the bone tissues as a phosphaturic hormone that upon secretion creates a trimeric complex with FGF receptor 1 and αKlotho. FGF-23 acts on the kidneys: it stimulates phosphate excretion and suppresses formation of active vitamin D. It has been proven that FGF-23 plays a role in bones’ carcinogenesis and its metastasis. The newly developed method based on the SPRi biosensor has been validated – the precision and accuracy as well as selectivity were acceptable and gave less than ±10% of recovery. The linear response of the biosensor ranges 1– 75 pg/ml. The limit of detection was 0.033 pg/ml and limit of quantification was 0.107 pg/ml. The biosensor was used to determine FGF-23 concentration in the plasma of healthy individuals as well as in the plasma of the patients with the clear cell carcinoma of the kidneys. The obtained results were compared with the results of the ELISA measurements. The determined Pearson correlation coefficients were close to 1 what showed that the newly developed biosensor can be used as the competitive method to the ELISA.

The magnetic field-assisted electrodeposition of iron–nickel thin films on different substrates (aluminum, silver, and brass) was investigated. The process was performed galvanostatically in a sulfate solution. The same chemical and electrical conditions were applied for each sample growth, but the time restrictions and the external magnetic field orientation were changeable. The obtained results show a variation of surface morphology and composition dependence on the selected surfaces as a consequence of the presence and orientation of the external magnetic field. We discussed that the FeNi crystal structure depends on the film thickness. The results show the reduction of the film thickness after the external magnetic field application—a decrease of deposition rate.The FeNi alloy’s morphology, composition, and magnetic properties were investigated by scanning electron microscopy (SEM), X-ray diffraction, energy dispersive X-ray spectroscopy (EDX), and Mössbauer spectroscopy (MS).

This paper refers to research based on tests completed on the adsorption of heavy metal ions (Pb²⁺, Cu²⁺, Cd²⁺) from selected natural liquid samples such as apple, tomato, and potato juices using surface-functionalized Mn ferrite nanoparticles (Mn_0.2Fe_2.8O₄). To determine the most efficient adsorption conditions of these heavy metals, the nanoparticles’ surfaces were modified with five different ligands (phthalic anhydride, succinic anhydride, acetic anhydride, 3-phosphonopropionic acid, and 16-phosphonohexadecanoic acid). To evaluate the success of the adsorption process, the resultant liquid samples were examined for the amount of residuals using the flame atomic absorption spectroscopy method. The Mn ferrite particles selected for these tests were first characterized physicochemically by the following methods: transmission electron microscopy, scanning electron microscopy, X-ray diffraction, IR spectroscopy, Mössbauer spectroscopy.