Search results for "muovit"
showing 4 items of 4 documents
Interacting effects of simulated eutrophication, temperature increase, and microplastic exposure on Daphnia
2020
The effects of multiple stressors are difficult to separate in field studies, and their interactions may be hard to predict if studied in isolation. We studied the effects of decreasing food quality (increase in cyanobacteria from 5 to 95% simulating eutrophication), temperature increase (by 3 °C), and microplastic exposure (1% of the diet) on survival, size, reproduction, and fatty acid composition of the model freshwater cladoceran Daphnia magna. We found that food quality was the major driver of Daphnia responses. When the amount of cyanobacteria increased from 5 to 95% of the diet, there was a drastic decrease in Daphnia survival (from 81 ± 15% to 24 ± 21%), juvenile size (from 1.8 ± 0.…
Advancements in Sustainable PVDF Copolymer Membrane Preparation Using Rhodiasolv® PolarClean As an Alternative Eco-Friendly Solvent
2021
In this work, Rhodiasolv® PolarClean was employed as a more sustainable solvent for the preparation of poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) flat sheet membranes via phase inversion technique by coupling vapour induced phase separation (VIPS) and non-solvent induced phase separation (NIPS) processes. Preliminary calculations based on Hansen solubility parameters well predicted the solubilization of the polymer in the selected solvent. The effect of exposure time on humidity and the influence of polyethylene glycol (PEG), polyvinyl pyrrolidone (PVP) and sulfonated polyether sulfone (S-PES) on membrane properties and performance, were evaluated. Three different coagulation …
Polymeerien lisäaineet ja lisäaineantioksidanttien kemialliset määritysmenetelmät
2017
Muovien käyttö on lisääntynyt runsaasti viimeisten vuosikymmenten ajan valmistus- ja työstöprosessien sekä lisäaineiden kehityksen myötä. Nykyaikaisten korkealaatuisten muovituotteiden valmistuksessa käytetään lukuisia erilaisia lisäaineita, joiden avulla pystytään vaikuttamaan esimerkiksi muovien pintaominaisuuksiin sekä pidentämään niiden käyttöikää. Käyttöikään vaikuttavat oleellisesti hapen aiheuttamat reaktiot polymeerirakenteessa ja näiden ei-haluttujen reaktioiden rajoittamiseksi on kehitetty erilaisia stabilointiaineita, kuten antioksidantteja. Muovien sisältämät lukuisat lisäaineet voivat reagoida keskenään aiheuttaen synergisiä tai antagonisia vaikutuksia, jolloin tiettyjen lisäai…
Optical Monitoring of Microplastics Filtrated from Wastewater Sludge and Suspended in Ethanol.
2021
The abundance of microplastics (MPs) in the atmosphere, on land, and especially in water bodies is well acknowledged. In this study, we establish an optical method based on three different techniques, namely, specular reflection to probe the medium, transmission spectroscopy measurements for the detection and identification, and a speckle pattern for monitoring the sedimentation of MPs filtrated from wastewater sludge and suspended in ethanol. We used first Raman measurements to estimate the presence and types of different MPs in wastewater sludge samples. We also used microscopy to identify the shapes of the main MPs. This allowed us to create a teaching set of samples to be characterized …