Hochschule für Life Sciences FHNW

Dauerhafte URI für den Bereichhttps://irf.fhnw.ch/handle/11654/22

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2012 - 20203

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Thema: search.filters.subject.620 - Ingenieurwissenschaften und Maschinenbau

Bereich: Suchergebnisse

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  • Kein Vorschaubild vorhanden
    Publikation
    Organic photovoltaics: Potential fate and effects in the environment
    (Elsevier, 2012) Zimmermann, Yannick-Serge; Schäffer, Andreas; Hugi, Christoph; Fent, Karl; Corvini, Philippe; Lenz, Markus
    In times of dwindling fossil fuels it is particularly crucial to develop novel “green” technologies in order to cover the increasing worldwide demand for energy. Organic photovoltaic solar cells (OPVs) are promising as a renewable energy source due to low energy requirement for production, low resource extraction, and no emission of greenhouse gasses during use. In contrast to silicium-based solar cells, OPVs offer the advantages of light-weight, semi-transparency and mechanical flexibility. As to a possible forthcoming large-scale production, the environmental impact of such OPVs should be assessed and compared to currently best available technologies. For the first time, this review compiles the existing knowledge and identifies gaps regarding the environmental impact of such OPVs in a systematic manner. In this regard, we discuss the components of a typical OPV layer by layer. We discuss the probability of enhanced release of OPV-borne components into the environment during use-phase (e.g. UV- and biodegradation) and end-of-life phase (e.g. incineration and waste disposal). For this purpose, we compiled available data on bioavailability, bioaccumulation, biodegradation, and ecotoxicity. Whereas considerable research has already been carried out concerning the ecotoxicity of certain OPV components (e.g. nanoparticles and fullerenes), others have not been investigated at all so far. In conclusion, there is a general lack of information about fate, behavior as well as potential ecotoxicity of most of the main OPV components and their degradation/transformation products. So far, there is no evidence for a worrying threat coming from OPVs, but since at present, no policy and procedures regarding recycling of OPVs are in action, in particular improper disposal upon end-of-life might result in an adverse effect of OPVs in the environment when applied in large-scale.
    01A - Beitrag in wissenschaftlicher Zeitschrift
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    Publikation
    Thermokinetic model of hydroxylamine decomposition in the catalytic oxidation of ammonia with titanium silicalite-1
    (Hochschule für Life Sciences FHNW, 23.10.2020) Walthert, Florian; Zogg, Andreas; Fabian Meemken Lonza
    Hydroxylamine is a key molecule for some important chemical processes. An example is the synthesis of ε-caprolactam, which is required for the production of Nylon. Since hydroxylamine decomposes thermally, its transport and storage are problematic. It is also problematic for the synthesis of hydroxylamine from ammonia with titanium silicalite-1. The goal of this study was to investigate the exothermic decomposition reaction. The heat of the reaction was measured in multiple DSC experiments. During the decompo sition, vast quantities of gases are released. To measure the pressure rise, an explosion reactor was employed. Three reaction hypotheses have been tested. With the use of a mathematical model one hypothesis could be proven. The material in uence on the de composition reaction was examined for PEEK, stainless steel and hastelloy C22. From the DSC measurements, a descriptive model and isoconversional kinetics were obtained.
    11 - Studentische Arbeit
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    Publikation
    Phosphorus recovery from sewage sludge by nanofiltration in diafiltration mode
    (Elsevier, 04/2015) Schütte, Thérèse; Niewersch, Claudia; Wintgens, Thomas; Yüce, Süleyman
    Phosphorus containing mineral fertilizers are frequently used in agriculture. The global resources of phosphorus rock are limited, which makes the use of alternative phosphorus sources increasingly promising. In this work, a process for phosphorus recovery from sewage sludge was studied. The focus lies on a nanofiltration process for the removal of metals and heavy metals from the product stream. In all cases, it was shown that metals were almost entirely retained by the membrane, while phosphorus permeated to a high degree. The phosphorus yield could be improved significantly by approaching diafiltration conditions.
    01A - Beitrag in wissenschaftlicher Zeitschrift