1. Green synthesis of a magnetite/graphitic carbon nitride 2D nanocomposite for efficient ▫$Hg^{2+}$▫ remediationRaghuraj S. Chouhan, Jan Gačnik, Igor Živković, Sreekanth Vijayakumaran Nair, Nigel Willy Van de Velde, Alenka Vesel, Primož Šket, Sonu Gandhi, Ivan Jerman, Milena Horvat, 2023, izvirni znanstveni članek Povzetek: Novel nanoadsorbents demonstrate the potential to efficiently eliminate harmful substances, such as Hg2+, from the environment while preserving ecological balance. However, the search for environmentally-friendly nanomaterials as ideal adsorbents, as well as the development of suitable synthesis protocols, remains a challenge. This study presents an effective thermal-sonication technique for producing unique de novo tris-s-triazine carbon nitride nanosheets decorated with magnetite nanoparticles (M-g-CN). The structural integrity and chemical properties of the M-g-CN nanocomposite were extensively characterized using a battery of analytical instruments, including FTIR, SEM, TEM, XRD, XPS, AFM, Raman, and NMR. The obtained data, along with the analysis results, are discussed in detail. The novel synthesis method yields a high percentage (97.7%) of stable, highly selective, and reusable M-g-CN (40 mg mL−1). The resulting M-g-CN effectively binds Hg2+, with binding efficiencies of 96.0%, 97.5%, 98.2%, and 99.4% for Hg2+ concentrations of 50 pg mL−1 in marine, stream, precipitation, and ultra-pure matrices, respectively. Also, the magnetite-decorated particles can be easily retrieved using an applied magnetic field. This greener and scalable synthesis method does not require harsh chemicals, making it cost-effective, eco-friendly, and non-toxic compared to other technologies such as carbon filters, ion exchange resins, chemical precipitation, membrane filtration, electrochemical methods, and biological remediation. Overall, the synthesized M-g-CN exhibits wide-ranging potential applications, particularly as a green adsorbent in passive samplers or materials for remediation purposes.
Ključne besede: mercury, elimination, nanoadsorbents, nanocomposites
Objavljeno v DiRROS: 05.01.2026; Ogledov: 271; Prenosov: 104
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2. Climate change reflected in 40-year isotopic composition trends of precipitation in SloveniaJan Gačnik, Klara Žagar, István Gábor Hatvani, Zoltán Kern, Polona Vreča, 2026, izvirni znanstveni članek Povzetek: Long-term monitoring of stable isotopes in precipitation (δ18O, δ2 H), alongside meteorological data, is key to understanding how large-scale hydroclimate variability influences regional and local climate. This study presents one of the longest records in Central and Southeastern Europe: the multi-decadal (1981–2024) dataset of monthly composite precipitation stable isotope records from Ljubljana, Slovenia. The δ18O, δ2 H, and d-excess values are increasing (+0.02 ‰, +0.18 ‰, and +0.05 ‰ per year, respectively), consistent with regional warming. Seasonal patterns were evident, with elevated d-excess values during autumn. The decomposition of the δ18O, δ2 H and d-excess time series using Hilbert-Huang Transform revealed statistically significant annual oscillations in all variables. These oscillations correlated strongly with the annual oscillation of temperature, but a lag of 2–3 months was identified for d-excess. Lower-frequency (multi-year) oscillations of d-excess were also observed. HYSPLIT back-trajectory analysis confirmed a significant contribution of Mediterranean-sourced air masses to autumn precipitation, but did not explain d-excess oscillations. Similar results were observed also for coastal (Portoroˇz, Slovenia) and continental (Vienna, Austria) stations. The findings imply an accelerating, exponential-like isotopic response to warming that has already propagated into the water cycle, providing isotope evidence that precipitation-surface water-groundwater interactions in investigated region changed in last decade.
Ključne besede: precipitation stable isotopes, trend analysis, Hilbert-Huang transform, ensemble empirical mode decomposition, HYSPLIT
Objavljeno v DiRROS: 19.11.2025; Ogledov: 267; Prenosov: 132
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