Search results for "PLASTICS"

Water-insoluble β-cyclodextrin–epichlorohydrin polymers for removal of pollutants from aqueous solutions by sorption processes using batch studies: A…

2017

This review is dedicated to Giangiacomo Torri (Istituto di Chimica e Biochimica G. Ronzoni, Milan, Italy) in celebration of his retirement.; International audience; Although water-insoluble cyclodextrin-epichlorohydrin polymers have been known for half a century, these materials are of continued interest to the scientific community, in particular for their interesting environmental applications as sorbents in liquid-solid sorption processes. However, in spite of the abundance of literature and conclusive results obtained at the laboratory scale, interpreting the mechanisms of pollutant elimination remains an interesting source of debate and sometimes of contradiction. This review summarizes…

Profiles and Sources of PAHs in Sediments from an Open-Pit Mining Area in the Peruvian Andes

2015

The Peruvian Andes are one of the most productive areas for mining and therefore also one of the most exposed to these sources of pollution. This article reports the characterization of Polycyclic Aromatic Hydrocarbons (PAHs) in sediments of Cerro de Pasco area (Peru) located close to a large open-pit mine and, in recent years, several reports have provided evidence of environmental contamination and related health problems. Investigations were carried out into the fifteen PAHs identified by the US-Environment Protection Agency (US-EPA) as requiring priority monitoring, other non US-EPA listed PAHs and perylene were also investigated in order to obtain further information on their origins. …

Microplastics in the Center of Mediterranean: Comparison of the Two Calabrian Coasts and Distribution from Coastal Areas to the Open Sea

2021

Plastic is everywhere—increasing evidence suggests that plastic pollution is ubiquitous and persistent in ecosystems worldwide. Microplastic pollution in marine environments is particularly insidious, as small fragmentation can increase interaction with biota and food chain access. Of particular concern is the Mediterranean Sea, which has become a large area of accumulation of plastic debris, including microplastics, whose polymeric composition is still largely unknown. In this study, we analyzed the polymeric composition, particle size distribution, shape, and color of small plastic particles (ranging from 50 to 5000 µm) collected from the sea surface in six stations at the center of the M…

Case Studies of Macro-and Microplastics Pollution in Coastal Waters and Rivers: Is There a Solution With New Removal Technologies and Policy Actions?.

2020

This opinion paper on microplastics pollution has selected different aspects and case studies of micro and macro-plastic litter pollution in coastal waters, and rivers. We point out a discussion on this topic and ask ourselves if there is a solution to the global problem by developing new microplastics removal technologies as well as policy actions. The first two case studies are related with macroplastics marine litter in beaches, a third report describes a new simple sampling device for microplastics in coastal and nearshore areas, five case study assess microplastics pollution in worldwide coastal environments, sediments and catchments (India, Mexico, Australia, Europe and the Nordic Sea…

Analysis and Prevention of Microplastics Pollution in Water: Current Perspectives and Future Directions

2019

The analysis, prevention, and removal of microplastics (MPs) pollution in water is identified as one major problem the world is currently facing. MPs can be directly released to water or formed by the degradation of bigger plastics. Nowadays, it is estimated that annually between 4 and 12 million tonnes of plastic go into the seas and oceans-with a forecast for them to outweigh the amount of fish in 2050. Based on the existing studies, the characterization of MPs in waters is still one of the remaining challenges because they can be easily confused with organic or other types of matter. Consequently, there is an urgent necessity to establish pathways for the chemical identification of the M…

Analysis of microplastics and nanoplastics: How green are the methodologies used?

2021

Microplastic (MP) and nanoplastic (NP) pollution is among the global environmental concerns of the 21st century owing to its transboundary distribution and persistence. The number of studies focused on the determination of MPs in air, water, sediment, soil, and biota of an important number of ecosystems has increased exponentially. However, the impact that the methodologies used to isolate and determine MPs and NPs have on the environment owing to the consumption of reagents and energy and the generation of waste is not yet studied. This review presents a critical overview of the analytical methodologies applied to determination of MPs and NPs assessing their greenness using the National En…

Microplastics in the global aquatic environment: Analysis, effects, remediation and policy solutions

2019

This opinion paper reports on Microplastics (MPs) pollution in the aquatic environment. MPs are a global problem being detected everywhere: marine environment, wastewaters, surface waters, soils, sediments, food and air. MPs can also absorb organic contaminants, and can be ingested by organisms and introduced into the food web. MPs can be a vector as well of pathogens whereas airborne fibrous MPs may enter our respiratory system with risk to the environment and humans. Main issues and gaps related to MPs on-going and future research are highlighted: chemical analysis, fate in wastewater and drinking water treatment plants, environmental and human health effects as well as remediation strate…

Stereocomplex Formation in Polylactide Multiarm Stars and Comb Copolymers with Linear and Hyperbranched Multifunctional PEG

2013

Preparation of Poly(l-lactic acid) Scaffolds by Thermally Induced Phase Separation: Role of Thermal History

2018

Abstract Poly-L-Lactic Acid (PLLA) scaffolds for tissue engineering were prepared via thermally induced phase separation of a ternary system PLLA/dioxane/tetrahydrofurane. An extension to solution of a previously developed method for solidification from the melt was adopted, the technique being based on a Continuous Cooling Transformation (CCT) approach, consisting in recording the thermal history of rapidly cooled samples and analysing the resulting morphology. Different foams were produced by changing the thermal history, the dioxane to THF ratio (50/50, 70/30, 90/10 v/v) and the polymer concentration (2, 2.5, 4 ° wt) in the starting ternary solution. Pore size, porosity, melting and crys…

Micelles of polyisobutylene-block-poly(methacrylic acid) diblock copolymers and their water-soluble interpolyelectrolyte complexes formed with quater…

2004

The micellization of ionic amphiphilic diblock copolymers, polyisobutylene-block-poly(methacrylic acid) (PIB-b-PMAA), with a constant degree of polymerization of the non-ionic block ðDPn ¼ 20Þ and various degrees of polymerization of the polyelectrolyte block ðDPn ¼ 100 – 425Þ was examined in aqueous media by means of fluorescence spectroscopy using pyrene as a polarity probe. The molar values of the critical micellization concentration (cmc) were found to be around 2 £ 10 26 mol/l, being nearly independent of the length of the polyelectrolyte block as well as pH (in the range 6 – 9) and ionic strength (# 0.5 M NaCl) while the specific cmc values varied from 20 to 100 mg/l. Small-angle neut…