21 research outputs found

    A review of technological solutions to prevent or reduce marine plastic litter in developing countries

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    Growing global plastic production combined with poor waste collection has led to increasing amounts of plastic debris being found in oceans, rivers and on shores. The goal of this study is to provide an overview on currently available technological solutions to tackle marine plastic litter and to assess their potential use in developing countries. To compile an inventory of technological solutions, a dedicated online platform was developed. A total of 51 out of initially 75 submitted solutions along the plastics value chain were assessed by independent experts. Collection systems represent more than half of the shortlisted solutions. A quarter include processing and treatment technologies, either as a stand-alone solution (30%) or, more commonly, in combination with a first litter capturing step. Ten percent offer digital solutions. The rest focuses on integrated waste management solutions. For each stage in the source-to-sea spectrum—land, rivers, sea—two illustrative examples are described in detail. This study concludes that the most cost-effective type of solution tackles land-based sources of marine litter and combines technology with people-oriented practices, runs on own energy sources, connects throughout the plastics value chain with a convincing valorization plan for captured debris, and involves all relevant stakeholders

    Total characterization of the BCl3-modified silica surface by means of quantitative surface analysis

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    The reaction of boron trichloride (BCl3) with a well characterized silica surface has been studied using Fourier-transform IR photoacoustic spectroscopy (FTIR-PAS) and quantitative boron and chloride analyses. Isolated and vicinal silanol groups, in addition to surface siloxane bridges, react with BCl3, resulting in the formation of chemisorbed monodentate or didentate surface groups. The parameters influencing the relative occurrence of these surface species have been investigated. A quantitative description of the grafted groups and reacted silanols has been obtained as a function of the pretreatment temperature of the silica, the reaction temperature and the reaction time

    Modelling of the reaction-phase interaction of Îł-aminopropyltriethoxysilane with silica

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    The coating formed in the reaction phase of the modification of silica with gamma-aminopropyltriethoxysilane was modelled using the freeze sampling method with a classical N-determination. The formation of a monolayer coating in the reaction phase is confirmed. Within the selected region of silane : silica ratio, the monolayer capacity value was determined to be 1.02 mmol g-1 on dehydrated silica gel and 0.63 mmol g-1 on the dehydroxylated substrate. The obtained monolayer structure is described and related to the specific surface area of the substrate used. APTS molecules are distributed over the silica surface with each molecule covering 64 angstrom2

    Toward resilient organizations after COVID-19: An analysis of circular and less circular companies

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    The COVID-19 pandemic had large repercussions for our economy and organizations. Improved resilience can give organizations the ability to withstand crises and build back better and faster. This article assesses resilience of organizations and sole proprietorships in the context of the COVID-19 pandemic with eight circular strategies as explanatory variables. Furthermore, these eight circular strategies are also used to assess the organizations’ and sole proprietorships’ resilience outside of the COVID-19 pandemic. This analysis is conducted to explain how circular strategies can help companies and sole proprietorships maintain stability. The analysis was performed by means of a survey conducted between May and June 2020 in Flanders (Belgium), using a sample of 542 respondents. After performing a regression analysis combined with expert opinions collected through interviews, we find that companies and sole proprietorships with a higher circularity score have a significantly higher resilience score during crises and during normal times, compared to less circular companies. Furthermore, we find that the size of the company does not matter during a crisis to adapt and react flexibly, while it is important when there is no crisis. Finally, we argue that it is the combination of different circular strategies which yields to the highest results for the organizations’ resilience and we provide policy recommendations based on the most asked support measures

    Reaction of NH3 with trichlorosilylated silica gel : a study of the reaction mechanism as a function of temperature

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    Activation of the silica substrate with chlorosilanes increases the ammonia uptake by a factor of 5-10, compared with untreated silica. The reaction mechanism of ammonia with trichlorosilylated silica gel is examined in detail. Physisorbed NH4Cl causes a shift in the Si-NH2 stretching vibrations. Several side reactions occur during the chlorosilylation step, the ammoniation step and the thermal treatment of the reacted sample. Amine functions subsequently convert to silazanes and eventually nitrides. A novel mechanism for silazane formation is proposed. The different species on the silica surface are quantified as a function of the reaction temperature
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