Search results for "plastics"

Effective Degradation of Cigarette Butts via Treatment with Old Landfill Leachates

2021

In this paper, results of feasibility study on microplastics (MPs) assessment in leachates from the Latvian solid municipal landfill Getliņi are discussed. The application of leachates for the treatment of cigarette butts (CGB) was evaluated. Methods of fluorescent microscopy, Fourier transform infrared (FTIR) spectroscopy and FTIR-microscopy were used for the identification and characterization of MPs in the leachates and analysis of CGB. Presence of the secondary MPs (e.g., degraded polyolefin mixtures) was determined in the tested landfill leachates, while cellulose acetate (CA) was not determined in these products. The leachates were tested as potential media for the thermophilic (55°C)…

Fate of microplastics in agricultural soils amended with sewage sludge: Is surface water runoff a relevant environmental pathway?

2021

Abstract Sewage sludge used as agricultural fertilizer has been identified as an important source of microplastics (MPs) to the environment. However, the fate of MPs added to agricultural soils is largely unknown. This study investigated the fate of MPs in agricultural soils amended with sewage sludge and the role of surface water runoff as a mechanism driving their transfer to aquatic ecosystems. This was assessed using three experimental plots located in a semi-arid area of Central Spain, which were planted with barley. The experimental plots received the following treatments: (1) control or no sludge application; (2) historical sludge application, five years prior to the experiment; and …

Ingestion of plastic and non-plastic microfibers by farmed gilthead sea bream (Sparus aurata) and common carp (Cyprinus carpio) at different life sta…

2021

Environmental pollution by plastic particles is of major global concern, as a potential threat to aquatic organisms and ecosystems. The accumulation of microplastics in freshwater and marine environments has strong ecological implications due to their long persistence, potential toxicity, and ability to adsorb other pollutants, acting as vectors of pathogens. Nevertheless, while the number of studies on the presence of microplastics in the wild fish increased, less attention has been paid to the farmed fish species. Here, we investigated the occurrence of microparticles in the digestive tracts of Sparus aurata and Cyprinus carpio at different life stages and reared by an intensive and semi-…

Corrigendum to “Bioaccumulation of emerging contaminants in mussel (Mytilus galloprovincialis): Influence of microplastics” [Sci. Total Environ. 796 …

2021

Nile Red lifetime reveals microplastic identity

2020

Microplastic pollution is recognized as a worldwide environmental problem. The increasing daily use and release of plastics into the environment have led to the accumulation of fragmented microplastics, with potentially awful consequences for the environment, and animal and human health. The detection and identification of microplastics are of utmost importance, but available methods are still limited. In this work, a new approach is presented for the analysis of microplastics based on hydrophobic fluorescence staining with Nile Red, using spectrally resolved confocal fluorescence microscopy and fluorescence lifetime imaging microscopy (FLIM). Significant differences were observed in the em…

Bioaccumulation of emerging contaminants in mussel (Mytilus galloprovincialis): Influence of microplastics

2021

Coastal environments are heavily influenced by human activities. Chemical substances considered as emerging contaminants (ECs) are one of the most important indicators of the anthropic influence on the environment, and they have recently shown to interact with microplastics (MPs). Mussels are suitable for in-lab bioacumulation studies providing insight about the occurrence and fate of contaminants in the organisms. In this study, bioacummulation of 20 chemical substances catalogued as ECs, including pharmaceuticals and personal care products (PPCPs), pesticides, and perfluoroalkyl substances (PFASs) in Mytilus galloprovincialis was assessed, with or without the influence of the presence of …

Identification of microplastics using 4‐dimethylamino‐4′‐nitrostilbene solvatochromic fluorescence

2021

In this work, we introduce the use of 4-dimethylamino-4'-nitrostilbene (DANS) fluorescent dye for applications in the detection and analysis of microplastics, an impendent source of pollution made of synthetic organic polymers with a size varying from less than 5 mm to nanometer scale. The use of this dye revealed itself as a versatile, fast and sensitive tool for readily discriminate microplastics in water environment. The experimental evidences herein presented demonstrate that DANS efficiently absorbs into a variety of polymers constituting microplastics, and its solvatochromic properties lead to a positive shift of the fluorescence emission spectrum according to the polarity of the poly…

Effects of various hygiene procedures on the surface characteristics of titanium abutments.

1996

The use of cleaning instruments on titanium implants may cause undesired surface alterations. In a qualitative and quantitative assessment of these alterations, 5 titanium implant abutments were treated with a steel curet, a prototype pure titanium curet, an air abrasive polishing system, and an ultrasonic system. Custom-made polymer templates, used to secure the curet to a vertical guide bar and a spring scale to maintain a constant instrument pressure, guaranteed a standardized procedure and reproducible results. The ultrasonic and the air abrasive polishing method were also standardized. Evaluation by scanning electron microscopy (SEM) revealed surface alterations for all instruments and…

Single Molecule Studies of a Ladder Type Conjugated Polymer: Vibronic Spectra, Line Widths, and Energy Transfer

2014

Confocal fluorescence microscopy and spectroscopy are employed to investigate single poly(ladder-type pentaphenylene) (LPPentP) molecules dispersed in thin poly(methyl methacrylate) (PMMA) films at 1.2 K. Emission spectra of single chains show single as well as multi-chromophore emission indicating variegated communication along the chains. The vibronic structure in the emission spectra resembles the one found for other ladder-type polymers. Purely electronic zero-phonon lines in emission are substantially broadened, most probably due to fast spectral diffusion. By surmounting the limitations of emission spectroscopy, nonemitting donor chromophores, which transfer their excitation energy in…

Improvement of interaction in and properties of PMMA-MWNT nanocomposites through microwave assisted acid treatment of MWNT

2013

Soluble derivatives of multi-walled carbon nanotubes (MWNT) embedded in a poly(methylmethacrylate) (PMMA) matrix forming thick, homogeneous and transparent nanocomposites, were prepared and characterized. A new photo-assisted method using microwaves, to purify the MWNTs from amorphous carbon and synthesis catalyst clusters, was tested in a sulphonitric mix. This method shortened the processing time compared to other methods. Pristine and functionalized MWNTs were introduced into the MMA, then in situ photo-polymerized. Transmission electron microscopy (TEM) and X-ray diffractometry (XRD), as well as Fourier-transform infrared (FTIR), Raman and nuclear magnetic resonance (NMR) spectroscopy w…