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Biogas production from solid food waste and its use for electricity productionKhune, Selebogo Mervyn 15 October 2021 (has links)
M.Tech. (Department of Chemical Engineering, Faculty of Engineering and Technology), Vaal University of Technology. / An enormous amount of food waste (FW) is generated worldwide. Most of this waste is discarded in landfills, where it undergoes uncontrolled anaerobic digestion (AD) process, which emits excessive amounts of greenhouse gases, (methane and carbon dioxide), thereby contributing to global warming. A controlled AD of FW is key for organic waste management with a positive impact on the environment and economy. In South Africa (SA) there is little uptake of biogas technology for FW management due to little research on biogas potential at small to large scale. Furthermore, there is an over reliance on foreign data, which leads to misfit parameters to local raw materials; consequently, producing biogas of low quality and quantity with low degradation of waste. Biogas with poor quality reduces the efficiency of biogas conversion to energy and the low production rate makes the system less feasible. Considering the challenges faced with FW management and the little uptake of the AD technology in SA, this study aimed to treat FW through AD and convert the biogas produced to electricity. A complete-mix biogas pilot plant (VUT-1000C) was designed, constructed and commissioned. The materials used for constructing the pilot plant were sourced locally to prove the applicability of the AD technology in SA. The biodigester was operated at mesophilic temperature, 37 oC, aided by a solar system. A stand-alone 1 m3 plug-flow ambient biodigester (STH-1000A) was operated semi-continuously as well as a control. Cow dung (CD) was used to inoculate the biodigesters, which were then operated semi-continuously at their optimum organic loading rate (OLR). The STH-1000A digester was operated at 0.446 kgVS/m3/day OLR, according to the manufacturer’s specification, while for VUT-1000C, the OLR was determined. The highest biogas and methane yields obtained were 582 and 332 L/kgVS/m3, respectively, at the determined optimal OLR of 1.5 kgVS/m3/day for the VUT-1000C digester this was supported by the modified Gompertz model with an R2 value of 0.9836. VUT-1000C produced 1200 L/day while STH-1000A produced 150 L/day. VUT-1000C proved to be a more effective biodigester than STH-1000A owing to the digester design and operation at mesophilic conditions. The key design findings are higher reactor working volume and high digester temperature. From the 1000 L of biogas produced from VUT-1000C, 1.8 kW of electricity was generated, which is equivalent to powering 300 6W light bulbs for 1 hour. The energy balance of the pilot plant showed that only 10 percent of the energy output was required to operate the plant. These results show that SA has a 475 GWh energy potential based on the current FW figures. Furthermore, the study has shown that biogas technology is readily available for South Africans and that the designed biogas plant was very efficient in FW-to-energy conversion.
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Kostråd till föräldrar vid introduktion av fast föda till spädbarn : BVC-sjuksköterskans erfarenheter - en pilotstudie / Nutritional advice to parents at the introduction of solid food to infants : Child health care nurses´ experiences - a pilot studyAli Mohamad, Amina, Nilsson, Jennika January 2014 (has links)
BVC-sjuksköterskan möter många föräldrar som har frågor om kostintroduktion till spädbarn, en av BVC- sjuksköterskans uppgifter är att undervisa föräldrar i kostfrågor. Studier har visat att föräldrar upplever att de får olika råd från BVC-sjuksköterskor, vilket kan göra föräldrarna osäkra på vilka råd de ska följa. Syftet med pilotstudien var att beskriva BVC-sjuksköterskans erfarenheter av att ge kostråd till föräldrar vid introduktion av fast föda till spädbarn. Fyra intervjuer genomfördes med BVC-sjuksköterskor inom barnhälsovården i Region Halland. Kvalitativ innehållsanalys användes som analysmetod. BVC-sjuksköterskorna upplevde att de gav god kostrådgivning till föräldrarna, varje familj sågs som unik och informationen anpassades till familjen på ett sätt som främjade föräldrarnas förmåga att följa barnets utveckling och identifiera barnets behov för en optimal introduktion av fast föda. Resultatet redovisas under kategorierna: strukturella faktorers betydelse för kostintroduktionen och familjens resurser och behov vid kostintroduktionen. En framtida fullskalig undersökning inom området skulle kunna ge underlag för strukturella förändringar inom BVC- verksamheten och utökade utbildningsinsatser för de som arbetar med eller kommer att arbeta med kostrådgivning vid introduktion av fast föda för spädbarn. / Child Health Nurses meet many parents with questions about infant´s food introduction, one of the child health nurse´s tasks is to educate parents on nutrition issues. Studies have shown that parents feel that they get different advice from Child Health Nurses, which can make them uncertain about which advice to follow. The aim of this pilot-study was to describe Child Health Nurse´s experiences of giving nutrition advice to parents at the introduction of solid foods to infants. Four interviews were conducted with Child Health Nurses within Child Health Servicesin Region Halland. Qualitative content analysis was used to analyze the text. The result of the pilot study shows that the Child Health Nurses felt that they gave good nutrition information to the parents related to structural factors of importance in food introduction and family resources and needs at food introduction. A future full-scale survey in the field could provide a basis for structural changes within the Child Health Services and enhanced educational initiatives for both Child Health Nurses and Child Health Nurse students.
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La notion de denrées alimentaires / Concept of food denreeDalmet, Christophe 18 December 2009 (has links)
Avec l’apparition massive des borderline products, les frontières traditionnelles entre la denrée alimentaire et les autres catégories de produits que l’on ingère ne cessent de se brouiller. Certes des éléments de définition de cette denrée se trouvent dans divers textes juridiques, notamment communautaires à l’image du règlement Food Law, mais toujours est-il que malgré tout demeure en partie le mystère identitaire qui entoure cette notion. Aussi, afin de pouvoir appliquer aux produits litigieux un statut adéquat et déterminer par la même le régime juridique qui doit être le leur, des références précises de l’aliment doivent être mises en évidence au travers de son analyse d’ensemble, l’étude tant de sa fonction que de sa présentation s’avérant indispensable pour résoudre cette problématique non dépourvue d’importance pratique / With the widespread appearance of borderline products, the traditional boundaries between the food and other categories of products that we ingest are constantly blurred. Then of course the defining elements of this commodity are in various legal texts, including the Community Food Law Regulation image, but the fact that still remains part of the mystery surrounding the identity concept. Also, in order to apply the products at issue and determine an appropriate status by the same legal regime that should be theirs, precise references to the food must be demonstrated through its comprehensive analysis, the study as its function as their presentation proving indispensable to solve this problem is not without practical importance
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