1. Use of hydrodynamic cavitation in (waste)water treatmentMatevž Dular, Tjaša Griessler Bulc, Ion Gutiérrez-Aguirre, Ester Heath, Tina Kosjek, Aleksandra Krivograd-Klemenčič, Martina Oder, Martin Petkovšek, Nejc Rački, Maja Ravnikar, Andrej Šarc, Brane Širok, Mojca Zupanc, Miha Žitnik, Boris Kompare, 2016, original scientific article Abstract: The use of acoustic cavitation for water and wastewater treatment (cleaning) is a well known procedure. Yet, the use of hydrodynamic cavitation as a sole technique or in combination with other techniques such as ultrasound has only recently been suggested and employed.
In the first part of this paper a general overview of techniques that employ hydrodynamic cavitation for cleaning of water and wastewater is presented.
In the second part of the paper the focus is on our own most recent work using hydrodynamic cavitation for removal of pharmaceuticals (clofibric acid, ibuprofen, ketoprofen, naproxen, diclofenac, carbamazepine), toxic cyanobacteria (Microcystis aeruginosa), green microalgae (Chlorella vulgaris), bacteria (Legionella pneumophila) and viruses (Rotavirus) from water and wastewater.
As will be shown, hydrodynamic cavitation, like acoustic, can manifest itself in many different forms each having its own distinctive properties and mechanisms. This was until now neglected, which eventually led to poor performance of the technique. We will show that a different type of hydrodynamic cavitation (different removal mechanism) is required for successful removal of different pollutants.
The path to use hydrodynamic cavitation as a routine water cleaning method is still long, but recent results have already shown great potential for optimisation, which could lead to a low energy tool for water and wastewater cleaning.
Keywords: wastewater, cleaning, hydrodynamic cavitation, pharmaceuticals, cyanobacteria, microalgae, viruses, Legionella bacteria
Published in DiRROS: 25.07.2024; Views: 103; Downloads: 48
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2. Biodiversity patterns of cyanobacterial oligotypes in lakes and rivers : results of a large-scale metabarcoding survey in the Alpine regionNico Salmaso, Serena Bernabei, Adriano Boscaini, Camilla Capelli, Leonardo Cerasino, Isabelle Domaizon, Tina Eleršek, Claudia Greco, Aleksandra Krivograd-Klemenčič, Paolo Tomassetti, Rainer Kurmayer, 2023, original scientific article Abstract: In this work, we characterised the cyanobacterial communities in the plankton and littoral biofilm of 38 lakes and in the biofilm of 21 rivers in the Alps and surrounding subalpine regions by 16S rRNA gene metabarcoding. We found little overlap in the distribution of amplicon sequence variants (ASVs) between the three habitats and between water bodies. The differences were caused by environmental filtering acting on the selection of the most abundant ASVs and a high contribution of rare oligotypes. The differentiation of community and genotype composition from specific water bodies was explained to a significant extent by environmental variables and morphometry. The taxonomic consistency of ASVs classified under the same genus name was assessed by phylogenetic analyses performed on three representative dominant genera, namely Cyanobium, Tychonema and Planktothrix. The analyses revealed eco-evolutionary adaptations in lakes and rivers, including some evidence for a polyphyletic nature. Monitoring individual genotypes in relation to environmental conditions will be useful to define the ecological amplitude of these taxa. However, the persistence or ephemeral nature of some of the rarest and most unusual ASVs has remained unknown.
Keywords: plankton, littoral, bioflm, European Alps, phylogenetic analysis, toxigenic cyanobacteria
Published in DiRROS: 15.07.2024; Views: 125; Downloads: 104
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3. Distribution of toxigenic cyanobacteria in Alpine lakes and rivers as revealed by molecular screeningMaša Jablonska, Leonardo Cerasino, Adriano Boscaini, Camilla Capelli, Claudia Greco, Aleksandra Krivograd-Klemenčič, Ute Mischke, Nico Salmaso, Rainer Kurmayer, 2024, original scientific article Abstract: The increasing frequency of cyanobacteria blooms in waterbodies caused by ecosystem eutrophication could endanger human health. This risk can be mitigated by effective monitoring incorporating molecular methods. To date, most molecular studies on toxigenic cyanobacteria have been limited to microcystins (MCs), disregarding other cyanotoxins, to freshwater planktic habitats while ignoring benthic habitats, and to limited geographic areas (usually one or a few specific waterbodies). In this study, we used PCR-based methods including PCR product sequencing and chemical-analytical methods (LC-MS/MS) to screen many plankton (n = 123) and biofilm samples (n = 113) originating from 29 Alpine lakes and 18 rivers for their cyanotoxin production potential. Both mcyE (indicating MC synthesis) and anaC (indicating anatoxin (ATX) synthesis) gene fragments were able to qualitatively predict MC or ATX occurrence. The abundance of mcyE gene fragments was significantly related to MC concentrations in plankton samples (R2 = 0.61). mcyE gene fragments indicative of MC synthesis were most abundant in planktic samples (65 %) and were assigned to the genera Planktothrix and Microcystis. However, mcyE rarely occurred in biofilms of lakes and rivers, i.e., 4 % and 5 %, respectively, and were assigned to Microcystis, Planktothrix, and Nostoc. In contrast, anaC gene fragments occurred frequently in planktic samples (14 % assigned to Tychonema, Phormidium (Microcoleus), and Oscillatoria), but also in biofilms of lakes (49 %) and rivers (18 %) and were assigned to the genera Phormidium, Oscillatoria, and Nostocales. The cyrJ gene fragment indicating cylindrospermopsin synthesis occurred only once in plankton (assigned to Dolichospermum), while saxitoxin synthesis potential was not detected. For plankton samples, monomictic and less eutrophic conditions were positively related to mcyE/MC occurrence frequency, while oligomictic conditions were related to anaC/ATX frequency. The anaC/ATX frequency in biofilm was related to the lake habitats generally showing higher biodiversity as revealed from metabarcoding in a parallel study.
Keywords: cyanotoxins, planktic and benthic habitats, water quality monitoring, early warning, toxigenic cyanobacteria, European Alps
Published in DiRROS: 03.06.2024; Views: 255; Downloads: 208
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