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no abstractni abstrakt

A study of the adsorption of titanium dioxide and zinc oxide nanoparticles on polyethylene microplastics and their desorption in aquatic media

In this study, we investigated the interactions between titanium dioxide (nTiO2) and zinc oxide (nZnO) nanoparticles and polyethylene microplastics (MPs) with respect to their adsorption and subsequent desorption in aquatic media. Adsorption kinetic models revealed rapid adsorption of nZnO compared to nTiO2, while nTiO2 was adsorbed to a greater extent – four times more nTiO2 (67%) was adsorbed on MPs than nZnO (16%). The low adsorption of nZnO can be explained by the partial dissolution of zinc from nZnO in the form of Zn(II) and/or Zn(II) aqua-hydroxo complexes (e.g. [Zn(OH)]+, [Zn(OH)3]−, [Zn(OH)4]2−), which were not adsorbed on MPs. Adsorption isotherm models indicated that the adsorption process is controlled by physisorption for both nTiO2 and nZnO. The desorption of nTiO2 was low (up to 27%) and not pH dependent, and only nanoparticles were desorbed from the MPs surface. On the other hand, the desorption of nZnO was pH dependentat a slightly acidic pH (pH = 6), 89% of the adsorbed zinc was desorbed from the MPs surface and the majority were in the form of nanoparticlesat a slightly alkaline pH (pH = 8.3), 72% of the zinc was desorbed, but the majority were in the soluble form of Zn(II) and/or Zn(II) aqua-hydroxo complexes. These results demonstrated the complexity and variability of interactions between MPs and metal engineered nanoparticles and contribute to a better understanding of their fate in the aquatic environment

Effect of Location, Disinfection, and Building Materials on the Presence and Richness of Culturable Mycobiota through Oligotrophic Drinking Water Systems

Safe drinking water is a constant challenge due to global environmental changes and the rise of emerging pathogens—lately, these also include fungi. The fungal presence in water greatly varies between sampling locations. Little is known about fungi from water in combination with a selection of materials used in water distribution systems. Our research was focused on five water plants located in the Pannonian Plain, Slovenia. Sampled water originated from different natural water sources and was subjected to different cleaning methods before distribution. The average numbers of fungi from natural water, water after disinfection, water at the first sampling point in the water network, and water at the last sampling point were 260, 49, 64, and 97 CFU/L, respectively. Chlorination reduced the number of fungi by a factor of 5, but its effect decreased with the length of the water network. The occurrence of different fungi in water and on materials depended on the choice of material. The presence of the genera Aspergillus, Acremonium, Furcasterigmium, Gliomastix, and Sarocladium was mostly observed on cement, while Cadophora, Cladosporium, Cyphellophora, and Exophiala prevailed on metals. Plastic materials were more susceptible to colonization with basidiomycetous fungi. Opportunistically pathogenic fungi were isolated sporadically from materials and water and do not represent a significant health risk for water consumers. In addition to cultivation data, physico-chemical features of water were measured and later processed with machine learning methods, revealing the sampling location and water cleaning processes as the main factors affecting fungal presence and richness in water and materials in contact with water