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The development of a framework to reduce water and energy consumption through the use of water and energy value stream mapping for the South African manufacturing industryDavies, Edward January 2015 (has links)
The Republic of South Africa’s energy economy is under immense pressure and the main energy utility, Eskom, cannot reliably generate sufficient electrical energy to meet its customer demand. Water security in South Africa is also under threat as the country is currently amidst a water crisis. The South African manufacturing industry is the sector consuming the largest portion of the total energy consumption and second largest portion of the total water consumption (excluding urban use) nationally. Water and energy efficiency improvement is becoming imperative for organisational success as well as national economic sustainability. This is due to the significant increase in the cost of both electrical energy and water in recent years, and the drop in the reserve energy margin below the minimum level required for sustainable operation of energy utilities. The research objective therefore was to develop a Lean-based water and energy efficiency improvement framework for the manufacturing industry to encourage and realise a reduced demand for energy and water in it. A literature review was conducted on the water and energy landscape in South Africa, Lean manufacturing principles and their positive natural influence on water and energy efficiency, and the Value Stream Mapping tool. The survey of water and energy wastes in the manufacturing industry yielded the creation of standardised water and energy waste categories for use in conjunction with the conventional Lean wastes, tools and techniques. The literature survey indicated that the implementation of Lean manufacturing techniques naturally leads to the improvement of energy and water intensity. The researcher hypothesised that there is even greater potential for water and energy savings if a Lean-based tool is developed to specifically focus on the improvement of energy and water efficiency. A framework for this tool was developed through the literature survey. The tool is based on the Value Stream Mapping tool. A practical experiment was then conducted to establish the effectiveness of the tool in the South African manufacturing industry. The experiment design included an outline of the forecasting and statistical validation techniques to ensure the integrity of data utilised for approving or disproving the set hypotheses. The results of the practical experiment yielded positive results, confirming the hypothesis that the implementation of the developed framework will lead to improved energy and water efficiency in the manufacturing industry. After an explanation of the experimental results, the study concluded with recommendations and conclusions based on the findings.
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An assessment of the impact of dry and wet cooling systems on stake holdersJonker, Markus Smith 06 February 2012 (has links)
M.Ing. / Water gives life. It waters the fields of farmers; it nurtures the crops and stock of rural communities; it provides recreation for our children, our friends, our families; it supports our power generation, our mines, our industry, and the plants and animals that make up ecosystems. Water is the key to development and a good quality of life in South Africa. South Africa's water belongs to its people. It is the task of the South African Government to care for this water, to seek its fair distribution, and to facilitate its wise use for, amongst other things, social and economical development. Issues such as water resource management, use, protection, water services, etc., are presently governed by a number of policies, acts and regulations. All South Africans has a responsibility regarding the management of the country's resources. The supply of water to its entire people makes it extremely important to optimise the use of this scarce source. Access to water and water availability remains a key factor in ensuring the sustainability of development in Southern Africa. The coal fired power industry is a major user of natural resources; coal for fuel and water for steam generation as well as the cooling systems. It is estimated that 1.5% of the water abstracted in South Africa is used for power generation. The power industry receives its water mainly as abstraction from surface impoundments in the form of rivers and dams. Eskom, as a strategic user of water, is mindful of the importance of water to its business, as well as the development of the country. In addition to the interests of the government as the shareholder, Eskom recognises the legitimate interests, as stakeholders, of specific government departments, employees, consumers, suppliers, investors and lenders of capital, rating agencies, the media, policy and regulatory bodies, trade unions, non-governmental groups and local communities in its affairs. Eskom needs to ensure, through an effective water management strategy, that water is used wisely and effectively and that Eskom's impact on local water resources (surface and underground) is minimised. Eskom therefore has to manage water resources in a manner that will sustain the ecological integrity, support social development and ensure economic growth. Eskom has undertaken to benchmark the power generation industry, in co-operation with the DW AF, in a project aimed at developing the principles of water conservation and water demand management. In order to effectively manage water quality and quantity at Eskom's power stations, and to show Eskom's commitment with regard to water conservation and use, Eskom has compiled its own water and environmental policies.
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Hot water consumption in South AfricaMuya, T.M. 10 September 2012 (has links)
M.Ing. / A one-year investigation on hot water consumption was conducted in South African developed and developing communities of Johannesburg to determine the personal and household average daily consumption of hot water as well as the average hourly (in summer and in winter) and monthly patterns. The motivation for this research project was to provide to engineers and water heaters manufacturers reliable experimental data on hot water consumption from various categories of dwellings. The existing sources of information in South Africa being extremely limited and results of estimations. The necessary information was collected from hourly and monthly measurements taken by monitoring hot water systems in different dwellings including, houses (300 units), traditional houses (90 units), shacks (200 units), apartments (123 units), townhouses (90 units). For the purpose of this study, the selected (not statistically) dwellings were classified into three categories, which are: high-density dwellings representing the developing communities, medium-density and low-density dwellings which represent the developed communities. The results of measurements show that, in general, people living in developed communities (low-density dwellings) use at least 1.4 times more hot water than those of developing communities (high-density dwellings). The patterns of hot water consumption have been determined for monthly and hourly consumption. The former is divided in four sections: summer weekdays, winter weekdays, summer weekends and winter weekends. The differences between sections are the specific times of peaks and the consumption. The results of this study should be of great assistance to engineers and water heaters designers in analysing existing systems for performance improvement, and in sizing more efficient and suitable systems to South African use.
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Utilização do resíduo úmido de cervejaria na alimentação de cabras anglo nubiana em final de lactação / Use of wet brewers in the anglo nubian goat feeding in late lactationMendonça, Lícia Mendes 25 April 2012 (has links)
This study aims to evaluate the intake, milk production and feeding behavior of dry matter (DM) and crude protein (CP) in goats in late lactation fed diets containing different levels of wet brewers (RUC): 0, 15, 20 25%. We used four Anglo Nubian
goats distributed in a 4x4 Latin square. The four experimental periods lasted thirteen days, 8 of adaptation and five collection of data and samples. The roughage used was
Tifton hay (Cynodon spp.) In forage: concentrate ratio 45:55. The animals were housed in individual stalls, fed twice a day. DM intake showed a linear effect of increasing levels of RUC diets with 0, 15, 20 and 25%, showing significant differences. There was a decrease in water intake, because the residue has a high moisture content. Milk production was not altered by the inclusion of the RUC, providing an alternative for
animal feed. Diets catered RUC part of the water needs of the animals, tending to decrease water consumption. In the assessment of eating behavior were measured with the time spent feeding, ruminating time, integration and idle time were evaluated by method of observations of animals every 20 minutes to complete 24 hours. Variables rumination time (TR), food (TA), idle (TO) and interaction (TI) showed no significant
differences, the values found with levels of substitution of the RUC did not provide differences from the control diet. The inclusion of the RUC to replace the protein source in diets did not affect milk production and feeding behavior, and recommended the use of 20% of RUC in the diet for meeting the requirements of DM, CP and TDN. In addition, diets RUC reduced water consumption by animals. / Este trabalho tem como objetivo avaliar o consumo, produção de leite e comportamento ingestivo da matéria seca (MS) e proteína bruta (PB) em cabras na fase final de lactação, alimentadas com dietas contendo diferentes níveis de resíduo úmido de cervejaria (RUC): 0, 15, 20 25%. Foram utilizadas 4 cabras Anglo Nubiana distribuídas em quadrado latino 4x4. Os quatro períodos experimentais tiveram duração de treze dias, sendo 8 de adaptação e 5 de coleta de dados e amostras. O volumoso utilizado foi o feno de tifton (Cynodon spp.) na relação volumoso:concentrado 45:55. Os animais foram alojados em baias individuais, alimentados duas vezes ao dia. O consumo de MS apresentou um efeito linear crescente entre os níveis das dietas com RUC 0, 15, 20 e 25%, demonstrando diferenças significativas. Houve uma diminuição na ingestão de água, devido o resíduo possuir um alto teor de umidade. A produção de leite não foi alterada com a inclusão do RUC, constituindo uma alternativa na alimentação animal. As dietas contendo RUC supriram parte das necessidades hídricas dos animais, tendendo a diminuir o consumo de água. Na avaliação do comportamento alimentar foram medidos os tempos despendidos com alimentação, tempo de ruminação,
integração e tempo de ociosidade que foram avaliados por metodologia de observações dos animais a cada 20 minutos até completarem 24 horas. As variáveis tempos de ruminação (TR), alimentação (TA), ociosidade (TO) e interação (TI) não apresentaram diferenças significativas, os valores encontrados com os teores de substituição do RUC não proporcionaram diferenças em relação a dieta controle. A inclusão do RUC em substituição a fonte de proteína nas dietas não alterou a produção de leite e o comportamento ingestivo, sendo recomendado a utilização de 20% de RUC na dieta por atender as exigências de MS, PB e NDT. Além disso, as dietas contendo RUC diminuíram o consumo de água pelos animais.
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Pegada hídrica da atividade suinícola na região do COREDE SerraCarra, Sofia Helena Zanella 20 July 2015 (has links)
A atividade suinícola, assim como as demais atividades pecuárias, é diretamente dependente de recursos naturais e, portanto, a falta de conhecimento acerca do impacto sobre os recursos hídricos na atividade pecuária pode comprometer o crescimento do setor. Neste contexto, a pegada hídrica surge como um indicador abrangente do uso da água que permite avaliar qual é o consumo utilizado, direta ou indiretamente, para produzir um determinado produto ao longo de toda a cadeia produtiva. Este trabalho avaliou a pegada hídrica no desenvolvimento da atividade suinícola na região do Corede Serra, no Estado do Rio Grande do Sul, considerando os suínos abatidos no ano de 2014. O cálculo da pegada hídrica foi aplicado para o processo de produção das culturas de milho e soja, destinadas à alimentação dos suínos (pegada hídrica verde), para o processo de confinamento, onde foram considerados os volumes de água destinados a dessedentação animal, limpeza das áreas de criação e incorporação ao animal (pegada hídrica azul) e o volume de água necessário para diluir a carga de fósforo que lixivia em direção aos recursos hídricos a partir da aplicação dos dejetos com fertilizantes (pegada hídrica cinza). A pegada hídrica verde foi a mais significativa (59,35%), seguida pela pegada hídrica cinza (40,44%) e pela pegada hídrica azul (0,21%). Observa-se que o maior consumo de água está na produção das culturas de milho e soja, que são a base da alimentação dos animais e não na água associada ao processo de confinamento. Para reduzir a pegada hídrica verde é necessário aumentar a produtividade de milho e soja, através de investimentos em tecnologias e zoneamento, associado a programas e políticas públicas com vistas ao aumento da produtividade das culturas. Investir em modelos de bebedouros mais eficiente, que forneçam um volume adequado de água e atendam à fase de criação animal, apresenta-se como uma opção de baixo custo para a economia de água e consequente redução da pegada hídrica azul. A pegada hídrica cinza pode ser reduzida através do uso de tecnologias mais eficientes de tratamento dos dejetos suínos, de forma que o fósforo seja removido ou reduzido em baixas concentrações antes de ser aplicado no solo. Ao aplicar a metodologia da pegada hídrica em uma unidade de referência composta por trinta e um município, observou-se que o nível de detalhamento das informações necessárias para se obter um resultado compatível com a situação real, é um verdadeiro desafio. Os resultados obtidos a partir deste trabalho poderão ser utilizados no planejamento das atividades suinícolas no Corede Serra com vistas a gestão dos recursos hídricos. / The pig activity, as well as other livestock activities, is directly dependent on natural resources. The lack of knowledge about the impact on water resources in the cattle industry can jeopardize the growth of the sector, highlighting the need for methodologies to assess the performance of the same. In this context, the water footprint comes as a comprehensive indicator of water use that evaluates what is the consumption used, directly or indirectly, to produce a particular product throughout the supply chain. Thus, this study aimed to evaluate the water footprint in the development of pig activity in the Corede Serra region, in the state of Rio Grande do Sul, considering the pigs slaughtered in the year 2014. The calculation of the water footprint was applied to the production process of corn and soybeans, aimed at feeding the pigs (green water footprint) and the confinement process, which were considered the volumes of water for animal watering, cleaning the areas of creation and incorporation into the animal (blue water footprint) and the volume of water needed to dilute the phosphorus load of bleach from the application of manure fertilizer and finds the water (gray water footprint). The green water footprint is the most significant (59.35%), followed by the gray water footprint (40.44%) and the blue water footprint (0.21%). It is observed that the highest water consumption is in the production of corn and soybean crops, which are the staple diet of the animals and not in the water associated with the confinement process. Reducing the green water footprint is necessary to increase the productivity of corn and soybeans, through investments in technologies and zoning, associated with programs and policies aimed at increasing crop productivity. Investing in more efficient models drinking fountains, giving an adequate volume of water and meet the phase of breeding, presents itself as a low-cost option for saving water and consequent reduction of the blue water footprint. The gray water footprint can be reduced through the use of more efficient technologies for processing of manure, so that phosphorus is removed or reduced to low levels before being applied to the soil. By applying the methodology of water footprint in a reference unit consisting of thirty-one municipalities, it was observed that the level of detail of the information required to obtain a result consistent with the actual situation, it is a real challenge. The results from this work will be used in the planning of pig activities in COREDE Serra with a view to managing water resources.
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Empresas e gestão da água: uma abordagem a partir do uso do indicador pegada hídrica / Corporation and Water Management: an approach based on the use of Water FootprintRenata de Souza Leão Martins 19 September 2014 (has links)
Nos últimos anos, as questões relacionadas à problemática ambiental multiplicaram sua presença na agenda do setor empresarial. Mais recentemente, observa-se o aumento do interesse das empresas pela água, recurso natural indispensável para a manutenção do equilíbrio dos ecossistemas e das atividades socioeconômicas humanas. Diante da ampliação da pressão sobre seu uso, resultado do crescimento populacional e incremento dos padrões atuais de produção e consumo, diferentes ferramentas têm sido desenvolvidas para contribuir para que o uso da água se torne mais racional e sustentável. Uma delas é a Pegada Hídrica (PH), um indicador de consumo direto e indireto da água utilizada durante a produção de bens ou serviços. A PH está relacionada com a pressão causada aos recursos hídricos pelas atividades humanas e classifica a água usada nesses processos e atividades de acordo com sua origem e impacto. Sua utilização pelo setor empresarial tem sido cada vez mais frequente. Tendo como base este contexto, este trabalho busca compreender quais são os principais motivos que tem levado as empresas a utilizarem a PH. Esta Tese, de caráter interdisciplinar, utiliza como referenciais teóricos a Teoria da Modernização Ecológica (TME), a Teoria dos Stakeholders (TS) e elementos da Nova Sociologia Econômica (NSE). Para alcançar o objetivo proposto, foram utilizados três procedimentos metodológicos: a) levantamento documental; b) revisão bibliográfica sistemática; c) estudos de caso. Os motivos que justificam a utilização da PH extraídos dos documentos analisados na revisão bibliográfica sistemática foram sistematizados e agrupados em quatro categorias que podem ser relacionadas com os referenciais teóricos utilizados. Os resultados obtidos na pesquisa indicaram que os motivos que têm levado as empresas a utilizarem a Pegada Hídrica são: 1) vantagens do método, já que permite uma visão detalhada do consumo de água em toda a cadeia produtiva (TME); 2) comunicação com stakeholders, pois reconhecem que é necessário avaliar o consumo da água em toda a sua cadeia, para atender as demandas dos diferentes stakeholders internos e externos e melhorar sua comunicação com eles (TS; NSE); 3) porque a PH pode colaborar na identificação de riscos associados à água, o que permite agir com certa antecipação a futuras regulações e contestações dos diferentes stakeholders (NSE); 4) porque os resultados dos estudos de PH podem fornecer informações que colabore na tomada de decisão para reduzir o consumo de água, estabelecer parcerias e cooperação entre os diferentes setores da sociedade (TME). Entre os motivos apontados, os mais frequentes são aqueles relacionados com as vantagens do método, o que permite uma compreensão mais ampla da pressão e impactos à água causados pelas atividades das empresas. Entretanto, considerando que sua utilização pelo setor empresarial é muito recente, pesquisas futuras necessitam ser realizadas para acompanhar a evolução das ações e do comportamento das empresas sobre a temática da água. Nesse sentido, torna-se cada vez mais urgente uma reflexão sobre a necessidade de que os limites físicos existentes e a capacidade de suporte dos ecossistemas orientem a organização das sociedades. / In recent years, several environmental issues have multiplied their presence in the corporate sectors agenda. More recently, an increased interest is observed among companies on the topic of water, an essential natural resource for the maintenance of ecosystems equilibrium and human socio-economic activities. To face the increasing pressure over the resource, resulting from the combination of population growth and changing consumption patterns, several tools have been developed. Their goal is to make corporate water consumption more rational and sustainable. One of these tools is the Water Footprint (WF), an indicator of direct and indirect water consumption in the production of goods and services. The water footprint quantifies and assesses the pressure from human activities on water resources. It classifies water resources according to their source and potential impact. Its use by the private sector is increasingly frequent. Against this context, this work aims at understanding the main reasons for companies adoption of the WF Assessment. This thesis, embracing a multidisciplinary approach, makes use of three theoretical frameworks: the Ecological Modernization Theory (EMT), Stakeholder theory (ST) and elements of the New Economic Sociology (NES). To this end, three different methodologies where used: a) document research; b) systematic literature research; c) case studies. The stated reasons for using the WF found in the literature research where classified into four categories that may be related to the theoretical frameworks presented. The results from this research identified as the main reasons under private sectors adoption of the WF. The first reason could be called advantages of this methodology, since it allows for a detailed analysis of water consumption in the supply chain, which can be analyzed using the EMT. A second reason would be related to the communication with the stakeholders. Companies recognize the need for addressing water consumption over their whole supply chain in order to meet the demands of different stakeholders and improve their communications with them. This recognition is explained by the ST and NES. Thirdly, risk assessment was is another important argument. WF assessment may help to address water-related risks, allowing them to anticipate the introduction of new regulations or contestation from different stakeholders. NES allows us to understand this reason. Lastly, companies include informed decision-making as another adoption reason. WF may be used for establishing goals and priorities for lower water consumption rates, identifying key partners and working together with key sectors of society. Ecological modernization theory contributes to explain this effect. The most frequent reasons mentioned were those related to the advantages of the methodology, arguing that the WF provides a broader understanding of pressure resulting from corporate activities. Nevertheless, considering the recent adoption by the private sector of this method, it would be important to re-evaluate the relation between water and the private sector, and with the WF in particular. In this sense, it is increasingly necessary that environmental limits and ecosystems carrying capacity guide societal organization.
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Posters as a passive intervention to reduce electricity and water consumption in the University of Pretoria's Groenkloof residencesMatsebula, Lindokuhle Benjamin January 2018 (has links)
Potable water is a relatively scarce natural resource. This scarcity is evident on a global scale. For humankind potable water is not only needed to sustain life, but also to engage in activities that maintain and enhance its own comfort and quality of life. These activities contribute to the degradation of water quality and exacerbating water scarcity. Electricity is a resource that needs to be generated, and is used significantly to also maintain and enhance human comfort, and quality of life. The generation of electricity produces a significant amount of greenhouse gases, gases that contribute to climate change. The use of both resources needs to be more ecologically sustainable to reduce the negative impact caused. Wherever possible, the use of these resources should be reduced. University residences utilise substantial amounts of water and electricity. This is because they are commonly designed to accommodate a large number of students. Implementing a behaviour change intervention in a residence therefore has the potential for greater ecological impact if the intervention is successful, due to the large number of people. There are different types of interventions aimed at changing behaviour, with some being active and others passive. Being active or passive is determined by whether or not direct interaction with the subject is required to achieve the desired change. Information provision can be a passive intervention by using posters and pamplets. It can also be active by using Q&A sessions and lectures. The study aimed to determine if the use of a passive behaviour change intervention could result in the reduction of water and electricity consumption in university residences. The passive intervention utilised was prompting in the form of posters. A quasi-experimental design with a mixed methods approach was employed. Quantitative data were meter readings for both electricity and water, while quantitative data were obtained from focus groups. 3 female residences at the University of Pretoria's Groenkloof campus were used in this study. Posters were placed at the points of decision in two of the residences. The third female residence was monitored as the control and no posters were put up in it. Monthly water and electricity meter readings were used to determine if this change had occurred. Focus groups were conducted to understand from the subjects how the intervention had affected them, if at all. Results from this study indicated that water and electricity consumption was reduced, with some reductions being statistically significant and others not. The study, however, cannot confidently predict that the intervention was successful due to various limitations. / Dissertation (MSc)--University of Pretoria, 2018. / Construction Economics / MSc / Unrestricted
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Övervakning av jordfuktighet med hjälp av mikrokontroller och sensorer på en travbana / Soil moisture monitoring with help of microcontrollers and sensors on a harness racing trackBlomqvist, Per, Andersson, Karl January 2022 (has links)
Tillgången till vatten kan ses som en självklarhet men 29\% av världens befolkning saknar tillgång till rent vatten. Vi alla måste ta ett ansvar för att minska vår förbrukning för att spara på den begränsade resurs som vatten faktiskt är. I denna rapport presenteras en lösning för att minska förbrukningen av vatten inom travsporten. Lösningen består av sensorer som mäter fuktigheten i jorden och en algoritm som räknar ut mängden vatten som behövs för att uppnå ett valt värde. För att utvärdera lösningen har en prototyp skapats. Prototypen har genomgått olika tester för att säkerhetställa att den uppfyller de krav och förväntningar som finns. Ett system som kan övervaka banan och få ett exakt värde på mängden vatten som behövs bidrar till en möjlighet att precisionsbevattna. Detta kan bidra till en reducering i vattenanvändningen. Förhoppningsvis så kommer travbanor att kunna dra nytta av denna rapport och hjälpa till med att bidra till en mer hållbar framtid där vi alla strävar efter att minska vår vattenförbrukning. / The access to water could be taken for granted, but 29 % of the world's population lacks access to clean water. We all need to take responsibility for reducing our consumption in order to save on the limited resource.to precision irrigateThis report presents a solution to reduce water consumption in trotting. The solution consists of sensors that measure the moisture level in the soil and an algorithm that calculates the amount of water needed to achieve a selected value. To evaluate the solution, a prototype has been created. The prototype has undergone various tests to ensure that it meets the requirements and expectations that exist. A system that can monitor the course and get an exact value for the amount of water needed contributes to an opportunity to precision irrigate.This could contribute to a reduction in water usage. Hopefully, trotting tracks will be able to benefit from this report and help contribute to a more sustainable future where we all strive to reduce our water consumption.
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Sustainability of Artificial Turf Fields : Comparative life cycle assessment of artificial and natural turf fieldsSäberg, Mikael January 2021 (has links)
Soccer accounts for a third of the Swedish sports movement with 3 503 fields of both natural and artificial turf. The European Union will make a decision in 2021 on how to handle the issue of rubber performance infill. This infill can be found in artificial turf fields and are used for performance properties. The problem with this infill is the microplastics that spreads into the nature which is considered as toxic. Because of this the EU have decided to either ban or provide mandatory rules to reduce the spread of rubber performance infill. The north and the majority of Sweden’s climate is not adapted for play of soccer on natural turf according to FIFA, and EU want to ban or provide mandatory rules for artificial turfs. This action from the EU can perturb the entire Swedish sports movement since soccer accounts for a third of that movement. This study was therefore created to show if artificial turf fields are as bad for the environment as rumours has said compared with the natural turfs. To investigate this, a life cycle assessment (LCA) was performed regarding the global warming potential (GWP) and embodied water consumption for three different field types: an artificial turf field with recycled SBR, an artificial turf field with cork and a natural turf field. The result visualised that a natural turf field had the highest embodied water consumption and the highest impact on the GWP of a ten-year life cycle while the artificial turf field with recycled SBR had the least embodied water consumption and the least impact on the GWP. The findings of this LCA were that Sweden for the moment is dependent on artificial turf and the rubber performance infill, since the material properties are the best adapted to their climate. Therefore, a ban would be a risk for the Swedish sports movement. It was also revealed that natural turf fields in Sweden consumes at least 50 % municipal drinking water when irrigate. The high GWP impact came from the production of fertilisers (NPK). This report has shown how artificial turf and natural turf can work together in an industrial symbiosis by making the artificial turf field constructed to collect rainwater and use that water to irrigate the natural turf with.
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A liquid consumption survey of individuals in greater Cape TownBourne, Lesley Thelma January 1986 (has links)
There is no published data for the per capita consumption of water of individuals in South Africa. A daily rounded volume of 2 litres per person is usually taken as a working estimate from world wide data. As part of ongoing epidemiological studies into potential health effects of changes in the water supply to greater Town, water consumption patterns were ascertained. As health effects are often spatially ascribed to the place of residence of a person, it was necessary to ascertain how much water was drunk at home as well as away from home. Water consumed was divided into three classes: (i) water consumed from the tap, (ii) commercial beverages and (iii) water bound in food. A review of methods of conducting dietary surveys indicated that a 24-hour recall would be the most appropriate method. Two surveys on total dietary intake utilizing a 24-hour recall were carried out (n = 2 000 persons for each survey), one in winter and the ether in summer. The design of the survey involved a cluster sample of households that were representative of the socio-economic and demographic structure of greater Cape Town. Three pretested types questionnaires were administered by trained interviewers: (i) a placement questionnaire to describe the household composition, (ii) a recall questionnaire for individual adults and children and (iii) a recall questionnaire for babies. Particular attention was paid to the accurate ascertainment of the volumes of food and drink consumed as well as their preparation to facilitate accurate analysis. The water content of each food item was calculated by a computer program that utilized computerized food composition tables. The water consumption data was analyzed by sex, age, population group, income and the season of the year. Detailed graphs and tables are provided. Results were also standardized to the population of greater Cape Town. It was found that the difference in consumption between the White and "Coloured" population groups was greater than the difference between those people of high and low-income groups. The mean total water intake for Whites was 2.19 litres per day, while for "Coloureds" it was 1.26 litres per day. There is no obvious bias to account for this difference. The figures for protein consumed by the two groups, which was used as a control, are consistent with values reported in the literature. Summer consumption was higher than that during winter. The ratio of tap water consumed at home to total liquid consumed was approximately 0.5.
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