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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
111

Matsvinn i skolverksamhet : En studie om hur kommunala grundskolor arbetar med att minska matsvinn inom två kommuner i norra Sverige / Food waste in schools : A study on how public schools are working to reduce food waste in two municipalities in northern Sweden

Nystedt, Jennie January 2018 (has links)
The purpose of this study was to investigate the efforts to reduce food waste in local primary schools in two municipalities in northern Sweden, as well as to highlight any similarities and differences. Food waste is a major problem around the world, globally an estimated 1.3 billion tonnes of food are thrown away each year. With a growing population and the environmental impact that is already provides significant consequences, it is not healthy that food that could be eaten are thrown away. Sweden alone are throwing away 1.2 million tonnes of food each year, and school kitchen alone contributes with approximately 40 000 tonnes. To answer the purpose of this study, electronic questionnaires were sent out to the principals for a total of 78 schools. The result of this study shows that 67 % of the schools participating in this study, has received directives from the municipality on how to work to reduce food waste in primary school. But even those who have not received directives from the municipality still perform activities when 12 out of thirteen schools in municipality A and all eight schools in municipality B stated that they actively working to reduce food waste. Even though the measures taken within schools were to some extent similar, the directives from the municipalities differed between schools, also within the same municipality. As consequence, participating schools worked differently with their students on this topic.
112

Nitrogen conservation by struvite formation during composting process with food wastes

Wang, Xuan 04 September 2015 (has links)
Food waste as a dominant fraction of municipal solid waste was in most of cases buried in landfills creating a burden on big cities with large populations such as Hong Kong. Composting provided an environmentally viable technology to divert food waste to resource utilization for the production of valuable organic fertilizer. The main problem associated with food waste composting was the intensive acidification prior the commencement of the composting process, which is commonly adjusted by the addition of alkaline materials such as lime. However, more than 50% of the initial nitrogen will be lost as ammonia, which not just reduces the nutrient value of the compost but also leads to serious odour generation. Therefore the objective of this study was to develop means to reduce the nitrogen loss through struvite formation. The first experiment of this research investigated the feasibility of controlling the nitrogen loss through struvite formation during food waste composting. Struvite forms when magnesium (Mg), phosphorus (P) and nitrogen (N) salts exist in equimolar ratio at a slightly alkaline pH. Thus to fix the ammonia, MgO and K2HPO4 were added to food waste indifferent molar ratios (P1, 0.05M/kg MgO and 0.05M/kg K2HPO4; P2, 0.05M/kg MgO and 0.1M/kg K2HPO4) to induce struvite formation that can fix the compost-borne ammonia during composting. The pH of the composting mass of P1 was below 5 for more than one. However, the pH of P2 was controlled in a narrow range from 6.8 to 8.7. This slightly alkaline pH ensured a good microbial activity and improved the degradation rate as well as the precipitation of struvite. In treatment P2, the formation of struvite effectively reduced the nitrogen loss from 40.8% to 23.3% when compared to treatment with lime amendment. However, electrical conductivity (EC) of the compost increased to 6.4 mS/cm due to the addition of Mg and P salts. High salinity of the compost retarded seed germination which required further investigation to reduce the salinity while maintaining good nitrogen removal. To overcome this issue, lime as the more effective alkaline amendment, was supplemented in different concentrations along with struvite salts (to P1 treatment having less Mg salt that could reduce the salinity) to alleviate the low pH and struvite formation. The pH of the composting masses were effectively increased with increasing lime dosages and 2.25% lime was sufficient to maintain the pH in alkaline condition that significantly improved the degradation of active organic compounds resulting in increased dissolved organic carbon (DOC) and soluble organic nitrogen (SON) contents. With 2.25% lime and struvite salts, ammonia emission was significantly reduced from 44.3 to 27.4% through struvite formation compared with lime alone treatment. Furthermore, the EC were also decreased from 5.21to 3.40 mS/cm when lime amendment rate increased from 0.75% to 3%. However, the ammonia emission increased with an increase in lime dosage. Interfering ions such as calcium and potassium were reported to affect the struvite formation and pH control. Therefore, in the subsequent experiment, the influence of different types of P salts was investigated to reduce the salinity as well as N loss. When K2HPO4, Na2HPO4 and H3PO4 were used as the supplementary P salts, there were no significant differences on nitrogen conservation. In addition, the results indicated that K+ and Na+ were attached on the surface of struvite rather than constituted the crystal structure. Compared with other P salts, the presence of K+ in K2HPO4 also made a contribution to total nutrient content that benefited the final product. When CaO was gradually substituted with MgO as pH amendment, ammonia emission was significantly reduced implying that Ca2+ ions would influence the struvite formation, either by competing for phosphate ions or by interfering with the crystallization. However, this negative effect could be ignored when the Ca2+/Mg2+ ratio was below 1:2. Considering the cost of MgO, supplementation of Ca2+/Mg2+ ratio at 1:2 (0.15M CaO and 0.3M MgO) with 0.05M K2HPO4 was identified as the optimum conditions (Treatment M0.3) that effectively reduced the nitrogen loss to 28% in contrast to 46% with lime addition. The significant reduction of ammonia emission through struvite formation was observed with the optimum condition that the odour unit (OU) of ammonia emission was reduced to 1.8×104 when compared with lime treatment (3.0×104) indicating a significant reduction of OIMAX (maximum odour index). Meanwhile, the well-controlled pH of this technology ensured the effective decomposition of organic matter that significantly reduced the emission of volatile fatty acids (VFAs) also. The population of total bacteria was also improved due to the addition of phosphate salts. The total nutrient content of struvite composts of treatment with optimum condition (M0.3) was 4.14% (1.5% N, 0.44% P and 2.2% K) that was higher than normal lime treated compost 2.92% (1.3% N, 0.34% P and 1.28% K). In pot experiment, soil was amended with composts at 0, 2.5%, 5% or 10% (w/w dry wt. basis). At the same application rate, the biomass yields of Chinese cabbage and cherry tomato plants were improved by struvite compost when compared tonormal compost. Considering the increasing salinity of soil with high application rate, the optimum dosage of 5% struvite compost is recommended. To conclude, a food waste composting technology was developed to achieve good nitrogen conservation and decomposition that alleviated odour issue and produced compost with higher nutrient contents, which increased its application value
113

Analyzing and controlling food waste inside supermarkets.Evaluation of implemented prototype to connect supermarkets with charities. Case study: Kosovo’s supermarkets

Gusinja, Bjeshka January 2018 (has links)
Food waste is considered to be a big problem worldwide. Different research projects have been done within this area in order to find ways that can help reduce this problem. This thesis addresses the problem of food waste in the supermarkets of Kosovo, by identifying the amounts of food waste in 3 supermarkets of this region. In addition, it explores the possibility of connection between supermarkets and charity organizations by using a developed prototype that corresponds to the field of web technologies. The prototype is implemented based on the feedback of supermarket workers. Interviews with open-ended questions were realized with supermarket workers and charity organization workers in order to identify the best medium that can be used to connect them. The prototype is realized using Wordpress, and evaluated first using the SUS questionnaire. Furthermore, it is also evaluated by performing usability test with supermarket and charity organization workers. The participants were asked to perform different tasks during the evaluation. The study shows that the use of the developed prototype reduces the amount of food waste in supermarkets. Furthermore, it successfully connects charity organizations with supermarkets. In addition, it provides a new way of controlling expiry dates of items resulting in reduction of waste inside supermarkets.
114

Enhanced methane gas generation by reutilization of acidogenic off-gas during two-phase anaerobic digestion of food waste

Yan, Binghua 27 January 2015 (has links)
Mass balance analysis of two-phase AD indicated that off-gas (H2 and CO2) produced in acidogenic reactor represent up to 30% of the consumed substrate and under most circumstances, this part of energy was not utilized leading to low overall energy recovery. Hence, the objective of this study was to enhance overall energy recovery during two-phase AD of food waste through reutilization of acidogenic off-gas and to further optimize the processes through manipulating the metabolic pathways and controlling acidogenic off-gas production. In the first phase, feasibility of reutilizing acidogenic off-gas in methanogenic reactor and contribution of acidogenic off-gas to overall energy recovery was investigated. Acidogenic off-gas diversion increased the methane gas (CH4, 0.28 L/g VSadded) production up to 38.6%, of which ~8% was contributed by acidogenic off-gas. Both higher hydrolysis rate and COD production were also achieved with off-gas diversion. Metabolic pathway determines the distributions of intermediate soluble products, which constitute the quality of acidogenic leachate. Therefore, two experiments focusing on manipulating metabolic pathways were performed. Firstly, the effects of four levels of headspace pressures, 6-12 psi (T1), ~3-6 psi (T2), ~3 psi (T3) and ambient pressure (T4) were investigated. Mixed acids metabolic pathways prevailed in all the treatments with butyrate as the single major component. Then, four different levels of H2 partial pressure (PH2) were set the next experiment, self-generated PH2 (T1, control), 80% of H2 (T2), 60% of H2 (T3) and 0.04% of H2, while the headspace pressure was kept at 3.3 psi. Typical butyrate fermentation pathways dominated in T4 whereas mixed acid fermentation pathways were prevailing in the other three treatments. Because of the improved hydrolysis/acidogenesis and higher quality of acidogenic products, overall CH4 recovery in T4 (301.0 L/kg VSadded) was 44.6% higher than the control. In Phase III, strategies to enhance acidogenic off-gas production were investigated. First, four types of neutralization modes including daily pH adjustment of leachate to 6.0, methanogenic effluent recirculation, and initial addition of NaOH and lime separately at a dosage of 20.0 and 14.0 g/kg food waste, respectively, were investigated. Obviously, a H2 production rate of 3.0 and 2.1 L/d with lime and NaOH addition was much higher than 0.7 and 0.4 L/d with effluent recirculation and daily adjustment, respectively. Also, addition of alkali agents could enhance the COD leaching of food waste, especially with NaOH. A CH4 production of 11.24 L/d could be attributed to both the elevated leachate quality and the acidogenic off-gas with lime addition. Another experiment investigated the effect of different carbohydrate contents in the substrates on acidogenic H2 production. Anaerobic hydrolysis of wastes sourced from bakery (T1), Chinese-style restaurant (T2), western-style restaurant (T3) and wet market were performed in LBRs. Food waste collected from western-style restaurant with a carbohydrate content of 69.5% achieved the highest H2 production of 61.0 L/kg VSadded. The highest specific CH4 production rate at 0.42 L/gVSadded was also achieved with western restaurant food waste. Finally, the possible redirection of fluxes associated with shift of metabolic pathways from the experiment of PH2 was proposed. Significant increase in the production of butyrate in treatment T4 with PH2 of 3.3 psi × 0.04% indicated the channeling of electrons towards the production of butyrate. Dynamics of the microbial community were correlated with the distribution of metabolites. In T1 without external gas flushing, lactic acid fermentation was dominant during the initial 7-days. Accordingly, phylotypes affiliated to the genus Lactobacillus sp. were detected. A heterlatic fermentation pathway was observed in in both T2 and T4 during first four days, and thereafter the fermentation pathways shifted towards acetate and butyrate as dominant products, which were accompanied by changing the microbial community with phylotypes of Clostridium sp. and Bifidobacterium sp. becoming dominant. To conclude, reutilization of acidogenic off-gas by diversion to methanogenic phase is a promising strategy for enhancing overall energy recovery during two-phase AD of food waste. However, improvement of the short-lived acidogenic H2 production and H2/CO2 ratio needs further investigation.
115

Avfallsprojekt Östersunds kommun : Avfallshantering och avfallsminskning i livsmedelsverksamheter

Zakrisson, Anna January 2018 (has links)
Waste is high up on the list when evaluations been done over the seriousness, size and trend of environmental aspects in the municipality of Östersund, Sweden. Environmental inspections are of need to reduce waste and reach a higher extent of waste separation. The board of environment and society have given the inspection authority the assignment to carry out a waste treatment project to evaluate if food operations fulfill the legislation demands on how to handle their waste in purpose of improving waste separation and reducing food waste. The environmental legislation in Sweden obliges everyone to prevent that people’s health and the environment gets negatively affected by the activities done. The legislation also obliges everyone to decrease, reuse and recycle waste. 29 food operations, who had the highest amount of registered food containers, have been inspected and interviewed with a questioning form and brochures with information and suggestions on how to separate waste and decrease food waste have been given out. Only two operations deviated from the legislation. There were ten operations that hade a complete separation of waste. 21 operations believed that the waste handling could improve and 13 operations where already working with reducing the amount of waste. All operations were working with reducing food waste and wanted to be able to minimize it even more. The outcome was positive with willingness to improve. But the awareness of legislation was low and the knowledge of why work is needed for the environment must get higher.
116

Valor nutricional de partes convencionais e não convencionais de frutas e hortaliças

Monteiro, Betânia de Andrade [UNESP] 19 December 2008 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:24:43Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-12-19Bitstream added on 2014-06-13T20:12:52Z : No. of bitstreams: 1 monteiro_ba_me_botfca.pdf: 668024 bytes, checksum: f5ae74ef60bcd570fedd8ddca841f350 (MD5) / As informações sobre a composição de vegetais cultivados em solos brasileiros são escassas e mais ainda de partes não convencionais dos alimentos, como cascas, talos e folhas. O desconhecimento dos valores nutricionais dessas partes induz ao mau aproveitamento, ocasionando o desperdício de toneladas de recursos alimentares. Como incentivo ao melhor aproveitamento dos alimentos e como alternativa de dieta nutritiva e de baixo custo, foram verificados o rendimento e as composições de calorias, proteínas, carboidratos, lipídeos, fibras, vitamina C, ferro, cálcio, potássio e umidade em partes convencionais e não convencionais de frutas e hortaliças, amplamente consumidas pela população. Os vegetais foram adquiridos em estabelecimentos comerciais da cidade de Botucatu / SP. As análises foram realizadas em polpas, cascas, flores, folhas ou talos de abacaxi, abóbora, beterraba, brócolis, chuchu, couve, couve-flor, manga, mamão, pepino e salsa. Para comparação entre as médias dos resultados, foi utilizado o teste de Tukey ao nível de 5% de probabilidade, sendo os valores encontrados mais significativos para carboidratos em frutas, proteínas em folhas, lipídeos em pequenas quantidades para todas as partes analisadas, fibras em todas as partes não convencionais, vitamina C em mamão, brócolis e salsa, ferro em folhas e talos de beterraba, cálcio em todas as folhas principalmente a de couve-flor e potássio em cascas de mamão e talos de brócolis e salsa. No presente trabalho pode-se concluir que a utilização integral dos vegetais pode auxiliar no alcance das necessidades nutricionais e na melhora do estado de saúde e qualidade de vida dos indivíduos, principalmente com a ajuda de programas que divulguem essas informações através de receitas práticas para o dia a dia e orientações para uma alimentação mais saudável e econômica. / The information about the composition of fruit and vegetables cultivated in Brazilian soil is scarce, and more so in relation to their mostly non-utilized parts, such as skins, peels, stalks and leaves. The lack of knowledge about the nutritional value of these nutriments often leads to their non-utilization, which results in the waste of tons of food resources. In order to stimulate better utilization of food and offer an alternative of nutritive diet at low cost, the yield and the composition of calories, proteins, carbohydrates, lipids, fibres, vitamin C, iron, calcium, potassium and humidity, in both the utilized and non-utilized parts of those fruit and vegetables, which are mainly consumed by the population, were analyzed. The fruit and vegetables were purchased in shops of the city of Botucatu / SP. The analyses were carried out in pulps, skins, flowers, leaves or stalks of pineapple, pumpkin, beetroot, broccoli, chayote, cabbage, cauliflower, mango, papaya, cucumber and parsley. For comparison between the average of the results, the Tukey test, at 5% level of probability, was used and the results found are more significant in relation to carbohydrates in fruit, proteins in leaves, lipids in small quantities for all the parts analysed, fibres in all non-utilized parts, vitamin C in papaya, broccoli and parsley, iron in leaves and stalks of beetroot, calcium in all leaves and mainly in cauliflower leaves and potassium in skins of papaya and stalks of broccoli and parsley. The present study concludes that the integral utilization of fruit and vegetables can assist in obtaining necessary nutrients and improving the state of health and quality of life of individuals, especially with the support of programmes that publicise this information through recipes and guidance towards a more economic and healthy eating.
117

Food waste matters - A systematic review of household food waste practices and their policy implications

Schanes, Karin, Dobernig, Karin, Gözet, Burcu 01 May 2018 (has links) (PDF)
In recent years, food waste has received growing interest from local, national and European policymakers, international organisations, NGOs as well as academics from various disciplinary fields. Increasing concerns about food security and environmental impacts, such as resource depletion and greenhouse gas emissions attributed to food waste, have intensified attention to the topic. While food waste occurs in all stages of the food supply chain, private households have been identified as key actors in food waste generation. However, the evidence on why food waste occurs remains scattered. This paper maps the still small but expanding academic territory of consumer food waste by systematically reviewing empirical studies on food waste practices as well as distilling factors that foster and impede the generation of food waste on the household level. Moreover, we briefly discuss the contributions of different social ontologies, more particularly psychology-related approaches and social practice theory. The analysis reveals food waste as a complex and multi-faceted issue that cannot be attributed to single variables; this also calls for a stronger integration of different disciplinary perspectives. Mapping the determinants of waste generation deepens the understanding of household practices and helps design food waste prevention strategies. Finally, we link the identified factors with a set of policy, business, and retailer options.
118

Household Food Waste Prevention in Malaysia: An Issue Processes Model Perspective

Abd Razak, Syahirah 03 November 2017 (has links)
Food waste has been a worldwide concern for several decades but this problem is relatively new in the Malaysian context due to the increasing amount of food waste in recent years. Thus, the goal of the study is to provide the basic information of knowledge and involvement level, and their interaction in food waste prevention among households in Malaysia. This study seek to further mass communication research in the area of food waste. The Hallahan’s Issues Processes Model was used within this study in order to determine the relationship between knowledge, involvement, and food waste prevention behavior. The convenience sampling method was adopted and the surveys were conducted using the online survey tool, Qualtric. The data were analyzed using SPSS 22.00 software. The results supported the hypotheses that the level of knowledge has a positive impact on food waste behavior only if the household’s involvement is high and vice versa. According to this model, Malaysian households fall under the category of an active audience, because they recognize the negative consequences and their acceptance that food waste prevention is personally relevant in their daily life. The findings of this study contribute further recommendations for government campaign that could focus on enhancing household planning skills and routines when it comes to the food preparation. Furthermore, the need for educational campaign against food waste should focus on selected information such as demographic background and presented in mass media to stimulate model behavior in the households.
119

Biohydrogen and Volatile Fatty Acids Production form Food Waste Hydrolysate

Lingam, Yaswanth January 2018 (has links)
This work focused a pH readjustment strategy has been applied for the enhancement ofbiohydrogen production form food waste hydrolysate in a semi-pilot scale bioreactor seededwith selectively enriched mixed microbial culture. Different initial pH (pH 6, pH 7, and pH8) was selected for biohydrogen production from FW. When hydrogen production was terminated due to the accumulation of volatile fatty acids in the bioreactor, then the pHof the bioreactor was again readjusted to its initial pH. Highest hydrogen production rate of1.13 L/h (CHP: 58.48 L) was achieved with pH 8 operation which was almost double thanpH 6 and pH 7 operation. Volatile fatty acids (VFA) production was also influenced by thisstrategy. Higher acetic and butyric acids (2471.4mg/L and 947.37mg/L) were observed. Highest buffering capacity (0.1ßmol) significantly contributed towards higher biohydrogenproduction via this pH adjustment strategy. This strategy not only enhanced H 2 productionbut it also increased the waste conversion efficiency towards other biobased productsproduction during acidogenesis of FW.
120

USO DE BIODIGESTOR ANAERÓBIO NO TRATAMENTO DE RESÍDUO ORGÂNICO DE RESTAURANTE / USE OF ANAEROBIC BIODIGESTER IN THE TREATMENT OF RESTAURANT ORGANIC WASTE

Granzotto, Fabiane 18 July 2016 (has links)
The generation of local solid waste has increased every year in Brazil. The largest portion of this waste is organic material. Organic waste generated in restaurants in the preparation of meals, as much as in the leftovers on the plates plays an important role in the composition of this type of waste and needs to be properly allocated. In the present study, the generation of biogas and bio compounds in the use of restaurant organic waste was evaluated, in an anaerobic digester. To achieve this, an anaerobic reactor of 120 L was used, which was operated and monitored from August 2015 to April 2016. The anaerobic digestion was conducted at mesophilic temperature close to 30 °C and at different hydraulic retention times of 30 and 60 days. Initially, the pH of the affluent varied from 4.8 to 6.4 performing in most cases as acid; therefore it was necessary to correct the incoming biomass with NaOH. The major physic-chemical factors which influenced in the process and the biogas composition (CH4 and CO2) were evaluated. The stable phase was identified and the removal efficiency of main physic-chemical parameters was verified during this stable period. The pH of the effluent on stage II varied from 6.2 to 7.3. The average COD removal was 95 %, BOD5, 93%, O&G, 86 %, ST, 51 %, SS, 92 % and STV, 76 %. The percentage of CH4 in phase II was 60 % and 40 % of CO2. During the period in which the digester was operated and evaluated the amount of 203 kg of restaurant organic waste was properly allocated, 633 L of water were used and 830 L of bio compounds were generated. The total volume of biogas followed in March and April 2016 was 3311.72 L and the estimated total volume for methane was 2123.24 L, in a range of daily variation biogas production from March to April of 41.2 L to 80.0 L. The study found that with the acclimatization of microorganisms was possible to obtain positive percentage of methane generation indicating that anaerobic digestion, for this type of waste used, is viable and it has good potential for use, in addition of generating gases production with potential energy and sludge with potential use in fertilization. / A geração de resíduos sólidos urbanos tem aumentado a cada ano, no Brasil. A maior parcela desses resíduos é de material orgânico. Os resíduos orgânicos gerados nos restaurantes, tanto do preparo das refeições, quanto das sobras nos pratos, tem participação importante na composição dos resíduos sólidos urbanos e precisam ser melhor destinados. No presente trabalho foi avaliada a geração de biogás e biocomposto através da utilização de resíduo orgânico de restaurante, em biodigestor anaeróbio. Para tanto foi utilizado um reator anaeróbio de 120 L, o qual foi operado e monitorado de agosto de 2015 a abril de 2016. A digestão anaeróbia foi realizada em temperatura mesófila, próxima de 30 °C e conduzida a diferentes tempos de retenção hidráulico de 30 e 60 dias. Inicialmente o pH do afluente variou entre 4,8 a 6,4 apresentando-se na maioria das vezes como ácido, por isso foi necessário corrigir a biomassa de entrada com NaOH. Foram avaliados os principais fatores físico-químicos que influenciavam no processo e a composição do biogás (CH4 e CO2). Foi identificada a fase estável e verificada a eficiência de remoção dos principais parâmetros físico-químicos avaliados durante este período estável. O pH do efluente na fase II variou de 6,2 a 7,3. A média de remoção de DQO foi de 95 %, da DBO5 foi de 93 %, dos O&G foi de 86 %, dos ST foi de 51 %, dos SS foi de 92 % e dos STV foi de 76 %. O percentual médio de CH4 na fase II foi de 60 % e o de CO2 de 40 %. Durante o período em que o biodigestor foi operado e avaliado foi mais bem destinada uma quantidade de 203 kg de resíduo orgânico de restaurante, foram utilizados 756 L de água e foram gerados 950 L de biocomposto. O volume total do biogás, acompanhado nos meses de março e abril de 2016, foi de 3311,72 L e o volume total estimado para o metano foi de 2123,24 L, sendo que a faixa de variação diária de produção do biogás de março a abril foi de 41,2 L a 80,0 L. O estudo apontou que com a aclimatação dos micro-organismos foi possível obter bons percentuais de geração de metano indicando que a digestão anaeróbia, para este tipo de resíduo utilizado é viável e tem bom potencial de uso, além de gerar gases com potenciais energéticos e lodo com potencial para uso em fertilização.

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