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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.
1

Institutional arrangements for resource recovery and reuse in the wastewater sector

Evans, Alexandra E. V. January 2016 (has links)
As populations grow and urban centres expand, meeting water demand and wastewater management requirements will become increasingly difficult. Goal 6 of the Sustainable Development Goals is to: 'Ensure availability and sustainable management of water and sanitation for all'. Part of the approach to achieving this will be reusing wastewater and will require a greater understanding of the institutional arrangements that support or obstruct reuse. This research was designed to achieve this and aimed to develop a set of factors that investors could use to assess the institutional feasibility of reuse in a given setting. The methodology combined a case study approach, focusing on wastewater systems in Bangalore, India and Hanoi, Vietnam, with triangle analysis to assess: the content of policies and laws; the structures (formal and informal) to implement laws and reuse projects; and the culture around acceptance and engagement in reuse. The reuse practices observed in Bangalore were treatment and use within apartments, centralized treatment and sale to industries, use in agriculture after natural attenuation, groundwater recharge and lake regeneration. In Hanoi the only reuse was indirect use from rivers feeding fish ponds and fields, although formal treatment and use is planned. Critically, both cities have environmental and water resources policies and laws that advocate reuse, as well as related local legislation. However, support for reuse is not reciprocated in industrial, agricultural or fisheries law, the result being that reuse does not always take place as planned. Legislation is required along the whole sanitation chain to the point of wastewater use. Structures to implement reuse are also vital. In Bangalore the water board has initiated reuse projects and established the New Initiatives Division but resources are a limiting factor. Effective institutions include expertise, manpower and financing mechanisms, which are lacking in both cities. The environment agency is also engaged in reuse though legislation on recycling in residential and commercial complexes but guidance for users is inadequate, expectations are perceived to be excessive and monitoring is almost impossible. The driver for reuse is increasingly the benefits observed by users. In the case of apartments this is a reliable water source and reduced costs of water supply. As a result, a private sector in wastewater treatment is becoming established. The active civil society and strong, independent media are instrumental in providing information to potential users and holding authorities to account in Bangalore. Their absence in Hanoi is notable. In summary, institutional elements to be considered are: supportive legislation across all sectors; details of acceptable reuse, deterrents and inducements; budget allocation; structures to enable reuse; strong civil society, NGOs, courts, media and universities providing evidence of suitability and safety; donors and finance mechanisms; and stakeholders willing to use the products. Encumbrances are inconsistent or uncoordinated legislation, lack of cooperation and insufficient benefit sharing or perceptions of benefits along the reuse chain.
2

Dishwashing Water Recycling System and Related Water Quality Standards for Military Use

Church, Jared 01 January 2014 (has links)
As the demand for reliable and safe water supplies increases, both water quality and available quantity are being challenged by population growth and climate change. Greywater reuse is becoming a common practice worldwide; however, in remote locations of limited water supply, such as those encountered in military installations, it is desirable to expand its classification to include dishwashing water to maximize the conservation of fresh water. Given that no standards for dishwashing greywater reuse by the military are currently available, the current study determined a specific set of water quality standards for dishwater recycling systems for U.S military field operations. A tentative water reuse standard for dishwashing water was developed based on federal and state regulations and guidelines for non-potable water, and the developed standard was cross-evaluated by monitoring water quality data from a full-scale dishwashing water recycling system using an innovative electrocoagulation and ultrafiltration process. A quantitative microbial risk assessment (QMRA) was also performed based on exposure scenarios derived from literature data. As a result, a specific set of dishwashing water reuse standards for field analysis (simple, but accurate) was finalized as follows: turbidity (< 1 NTU), E. coli (< 50 cfu mL-1), and pH (6–9). UV254 was recommended as a surrogate for organic contaminants (e.g., BOD5), but requires further calibration steps for validation. The developed specific water standard is the first for dishwashing water reuse and will be expected to ensure that water quality is safe for field operations, but not so stringent that design complexity, cost, and operational and maintenance requirements will not be feasible for field use. In addition the parameters can be monitored using simple equipment in a field setting with only modest training requirements and real-time or rapid sample turn-around. This standard may prove useful in future development of civilian guidelines.
3

Análisis y caracterización de las instalaciones interiores de suministro de agua desde el punto de vista de ahorro

López Patiño, Gonzalo 07 March 2016 (has links)
[EN] SUMMARY It is a fact that in our environment there is a water shortage that affects the agricultural and urban freshwater consumption. The environmental conditions of climate change will aggravate the situation in the coming years. The efficient management of water resources is, and will be, an important issue for society that must be addressed from a social and technological point of view. Although nonfarm consumption represents only 30% of the total demand for freshwater, the urban water use is the more worrying because it directly affects the lives of people. A shortage of water resources is answered from two points of view. On the one hand, increasing supply through an increase in water uptakes, transfers from surplus basins, or desalination. On the other hand the reduction of demand, or efficient demand management. It is from this approach where this research takes place. The aim of the thesis is to develop a methodology to select the most appropriate water saving system to equip a building. The selection process arises from two approaches, each corresponding to a different use of the building. For buildings intended to develop a productive activity a cost-benefit selection method is used. For other buildings, a multicriteria selection method is used. For this last situation, application of analytic hierarchy process to selection of water saving systems is chosen. For the implementation of the multicriteria selection method, a series of selection criteria have to be defined and considered: water conservation, energy conservation, social and environmental impact, design, and economic viability. Each device or water saving system should be characterized on the basis of each of these criteria. In the thesis has been developed the way to characterize the "water efficient systems" for every of the selection criteria defined. As part of the characterization process, it is necessary to know drinking water demand patterns produced in the building. To do this, a water consumption audit can be performed, for the existing buildings, or results of similar buildings can be extrapolated, in the event that the building were a new construction that is going to be equipped with water efficient systems. The thesis shows how to carry out an audit of water consumption of the building. Also, some studies of water demand patterns in residential buildings are set. A self-done study on water patterns demands in the area of Valencia is presented. For the economic viability of implementing water saving systems it is very important that the size of all its equipments are as tight as possible to the use made of them in the building. Therefore, a study of the optimal and economic dimensioning of rain water harvesting systems has been made. It has also been theoretically studied the generating capacity of water condensation in air conditioning systems, for its use in water supply facilities. This information is used for equipment sizing of this water saving system. As there was no verified information on the validity of the theoretical method, measurements have been performed to contrast them. Finally, in this thesis measurements, studies, analysis, and equipment characterization, had been performed to make available a complete methodology for multi-criteria selection of the most suitable water efficient systems to equip a given building. / [ES] RESUMEN Es una realidad que en nuestro entorno existe un déficit hídrico que afecta tanto al consumo agrícola de agua dulce como al consumo urbano de agua potable. Las condiciones ambientales de cambio climático agravarán la situación en los próximos años. La gestión eficiente de los recursos hídricos es, y será, un tema importante para la sociedad que debe ser abordado desde un punto de vista social y tecnológico. Aunque el consumo no agrícola supone sólo una 30% de la demanda total de agua dulce, es el uso urbano del agua, que consume la mayor parte de ese porcentaje, el más preocupante por cuanto afecta directamente a las condiciones de vida de las personas. A la escasez de recursos hídricos se responde desde dos perspectivas. Por un lado el aumento de la oferta, a través de un aumento de las captaciones, trasvases desde cuencas excedentarias, o desalación. Por otro lado la reducción o gestión eficiente de la demanda. Es desde este enfoque desde donde se desarrolla este trabajo de investigación. El objetivo de la tesis doctoral es desarrollar una metodología para la selección de los sistemas de ahorro de agua potable más adecuados para equipar en un edificio. El proceso de selección se plantea desde dos aproximaciones, correspondiendo cada uno de ellos a un uso diferente del edificio. Para los edificios destinados a desarrollarse una actividad productiva se utiliza un método de selección coste-beneficio. Para el resto de edificios se utiliza un método de selección multicriterio. Para esta situación se ha optado por aplicar el método del proceso analítico jerárquico a la selección de sistemas de ahorro de agua. Para la aplicación de la selección multicriterio, se han definido una serie de criterios a tener en cuenta: ahorro de agua, ahorro de energía, impacto socio-ambiental, diseño, y viabilidad económica. Cada dispositivo o sistema de ahorro de agua debe ser caracterizado en base a cada uno de estos criterios. En la tesis se ha desarrollado la forma de caracterizar los denominados "sistemas de hidroeficiencia" para cada uno de los criterios de selección definidos. Como parte del proceso de caracterización, es necesario conocer la forma de consumir agua potable que se produce en el edificio. Para ello se puede realizar una auditoría de demandas, en el caso que el edificio exista, o se debe extrapolar resultados de edificios similares, en caso que el edificio sea un edificio de nueva planta que se quiere equipar con los sistemas de hidroeficiencia, ya de partida. En la tesis se indica cómo llevar a cabo una auditoría del consumo de agua del edificio. Igualmente se exponen algunos estudios de patrones de consumo en edificios de viviendas, y se presenta un estudio propio sobre patrones de demanda en la zona de Valencia, para la que no existía información. Para la viabilidad económica de la implantación de los sistemas de ahorro tiene gran importancia que su tamaño sea lo más ajustado posible al uso que se hace de ellos en el edificio. Por ello, se ha hecho un estudio del dimensionado óptimo y económico de los sistemas de aprovechamiento de aguas pluviales. Igualmente se ha estudiado de forma teórica la capacidad de generación de agua de condensación de los sistemas de climatización, para su aprovechamiento en las instalaciones de suministro de agua. Dicha información se utiliza para el dimensionado de los equipos de ese sistema de hidroeficiencia. Como no había información contrastada sobre la validez del método teórico, se han realizado mediciones para contrastarlos. Con todo, en la tesis que se presenta se han realizado las mediciones, estudios, análisis y caracterización de equipos necesarios para que se disponga de una metodología completa para la selección multicriterio de los sistemas de hidroeficiencia más adecuados para equipar un determinado edificio. / [CAT] RESUM És una realitat que en el nostre entorn hi ha un dèficit hídric que afecta tant el consum agrícola d'aigua dolça com al consum urbà d'aigua potable. Les condicions ambientals de canvi climàtic agreujaran la situació en els pròxims anys. La gestió eficient dels recursos hídrics és, i serà, un tema important per a la societat que ha de ser abordat des d'un punt de vista social i tecnològic. Encara que el consum no agrícola suposa només una 30% de la demanda total d'aigua dolça, és l'ús urbà de l'aigua, que consumix la major part d'eixe percentatge, el més preocupant ja que afecta directament les condicions de vida de les persones. A l'escassetat de recursos hídrics es respon des de dos perspectives. Per un costat l'augment de l'oferta, a través d'un augment de les captacions, transvasaments des de conques excedentàries, o dessalatge. Per un altre costat la reducció o gestió eficient de la demanda. És des d'este enfocament des d'on es desenrotlla este treball d'investigació L'objectiu de la tesi doctoral és desenrotllar una metodologia per a la selecció dels sistemes d'estalvi d'aigua potable més adequats per a equipar en un edifici. El procés de selecció es planteja des de dos aproximacions, corresponent cada un d'ells a un ús diferent de l'edifici. Per als edificis destinats a desenrotllar-se una activitat productiva s'utilitza un mètode de selecció cost-benefici. Per a la resta d'edificis s'utilitza un mètode de selecció multicriterio. Per a esta situació s'ha optat per aplicar el mètode del procés analític jeràrquic a la selecció de sistemes d'estalvi d'aigua. Per a l'aplicació de la selecció multicriterio, s'han definit una sèrie de criteris a tindre en compte: estalvi d'aigua, estalvi d'energia, impacte socioambiental, disseny, i viabilitat econòmica. Cada dispositiu o sistema d'estalvi d'aigua ha de ser caracteritzat basant-se en cada un d'estos criteris. En la tesi s'ha desenrotllat la forma de caracteritzar els denominats "sistemes de hidroeficiencia" per a cada un dels criteris de selecció definits. Com a part del procés de caracterització, és necessari conéixer la forma de consumir aigua potable que es produïx en l'edifici. Per a això es pot realitzar una auditoria de demandes, en el cas que l'edifici existisca, o s'ha d'extrapolar resultats d'edificis semblants, en cas que l'edifici siga un edifici de nova planta que es vol equipar amb els sistemes de hidroeficiencia, ja de partida. En la tesi s'indica com dur a terme una auditoria del consum d'aigua de l'edifici. Igualment s'exposen alguns estudis de patrons de consum en edificis de vivendes, i es presenta un estudi propi sobre patrons de demanda en la zona de València, per a la que no existia informació. Per a la viabilitat econòmica de la implantació dels sistemes d'estalvi té gran importància que la seua dimensió siga el més ajustat possible a l'ús que es fa d'ells en l'edifici. Per això, s'ha fet un estudi del dimensionat òptim i econòmic dels sistemes d'aprofitament d'aigües pluvials. Igualment s'ha estudiat de forma teòrica la capacitat de generació d'aigua de condensació dels sistemes de climatització, per al seu aprofitament en les instal·lacions de subministrament d'aigua. La dita informació s'utilitza per al dimensionat dels equips d'eixe sistema de hidroeficiencia. Com no hi havia informació contrastada sobre la validesa del mètode teòric, s'han realitzat mesuraments per a contrastar-los. Amb tot, en la tesi que es presenta s'han realitzat els mesuraments, estudis, anàlisi i caracterització d'equips necessaris perquè es dispose d'una metodologia completa per a la selecció multicriterio dels sistemes de hidroeficiencia més adequats per a equipar un determinat edifici. / López Patiño, G. (2016). Análisis y caracterización de las instalaciones interiores de suministro de agua desde el punto de vista de ahorro [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/61476 / TESIS
4

The treatment of platinum refinery wastewater using an evaporative crystallizer

Luvuno, Jabulani Heavenson 03 1900 (has links)
South Africa is a water scarce country. The expansion of the industrial, mining, and agricultural sectors to meet the needs of South Africa’s growing population requires more water. There is therefore an urgent need to develop effective wastewater treatment processes in order to recover and reuse water. This dissertation presents the treatment of an acidic wastewater stream from a platinum refinery which at present is being disposed of by contract with a waste disposal company. The major concern in treating the acid effluent stream is the high concentration of sodium ions (18 200 mg/l) and chloride ions (104 900 mg/l). The precipitation process is used to treat wastewater, but ultimately it generates more secondary waste as a sludge. The other process that is used to treat wastewater is reverse osmosis (RO). RO is usually preferred in the last stage of the treatment because the process is more expensive as membranes need to be replaced regularly. The approach used in this research focuses on evaporating liquid, consequently concentrating the remaining solution until the ions in the solution crystallize. The liquid produced is recycled back into the platinum plant for reuse, and the remaining salt crystals are collected as the useful product. The proposed water treatment process produces dilute hydrochloric acid as the condensate and a crystallized sodium chloride rich residue. The refinery is currently disposing of around 20 000 l/day of wastewater to landfills. The proposed treatment process can recover half of the volume of the wastewater stream to the refinery, helping reduce the fresh water consumption of the process by 10 000 l/day. Furthermore, this will reduce the volume of wastewater going to disposal by a half, namely only 10 000 l/day will need to be disposed of. The amount of Cl that can be recovered is variable and depends on the quantity of chloride in the wastewater. In the two samples processed the recovery was between a 2,5 w% and 10,7 wt% aqueous HCl solution. This corresponds to a saving of between 250 to 1000 kg/day of HCl. As the concentration of the recovered solution is variable, the recycling process would need to monitor the composition of the recycled stream and make up the acid concentration to some fixed value for reuse in the prices. The production of a dilute hydrochloric acid stream should be particularly attractive to the platinum refinery as the operation of the refinery requires hydrochloric acid as a feed. Thus, by recycling the wastewater, the refinery would reduce the volume of wastewater to be disposed of thereby reducing the cost of disposal of the waste while simultaneously reducing the cost of buying fresh hydrochloric acid. The proposed recovery of liquid and recycling it back to the refinery, will also reduce the environmental impact of the refinery, and very importantly in a water scarce country, reduce the freshwater consumption of the process. / Physics / M. Sc. (Physics)
5

Potential for water reuse in Vietnam

Oertlé, Emmanuel, Vu, Duc Toan, Nguyen, Dinh Chuc, Näf, Laurin, Müller, Sandra Regina 14 May 2020 (has links)
Southeast Asian countries and Vietnam in particular are facing water security challenges; water reclamation is increasingly being considered as a favorable solution. Despite the availability of suitable technologies, several constraints often prevent stakeholders and especially decision makers exploiting their potential. In this paper we present the results of applying a decision support tool (DST) to evaluate water reclamation, support pre-feasibility studies and build capacity for water reclamation in Vietnam. The DST and its data are open access, providing information related to local and international water and wastewater quality standards. In this research we identified high potential Vietnamese case studies and conducted a systematic PISTLE analysis considering six dimensions (Political, Institutional, Social, Technical, Legal and Economic) at a multiple local stakeholder workshop. Key barriers and drivers for water reclamation implementation were identified. Measures proposed during the workshop could serve as a starting point for the development of water reclamation projects in Vietnam. / Các nước Đông Nam Á và đặc biệt là Việt Nam nói riêng hiện đang phải đối mặt với những thách thức về đảm bảo an ninh nguồn nước; cải tạo nguồn nước hiện đang được xem là một giải pháp thuận lợi. Mặc dù các công nghệ phù hợp đã có sẵn, nhưng một số hạn chế đã ngăn cản các bên liên quan và đặc biệt là những nhà làm chính sách có thể khai thác các tiềm năng của những công nghệ này. Trong bài báo này, chúng tôi trình bày các kết quả của việc áp dụng một công cụ hỗ trợ quyết định (DST) để đánh giá việc cải tạo nguồn nước, hỗ trợ các nghiên cứu tiền khả thi và xây dựng các khả năng cải tạo nguồn nước ở Việt Nam. DST và dữ liệu của nó là nguồn truy cập mở, cung cấp thông tin liên quan đến những tiêu chuẩn về chất lượng nước và nước thải của địa phương và quốc tế. Trong nghiên cứu này, chúng tôi đã xác định các tình huống điển hình có tiềm năng cao của Việt Nam và tiến hành phân tích PISTLE có hệ thống xem xét sáu khía cạnh (Chính trị, Thể chế, Xã hội, Kỹ thuật, Pháp lý và Kinh tế) tại một hội thảo của các bên liên quan tại địa phương. Những rào cản chính và yếu tố vận hành của việc thực hiện cải tạo nguồn nước cũng đã được xác định. Các giải pháp được đề xuất trong hội thảo này có thể đóng vai trò là điểm khởi đầu để phát triển các dự án cải tạo nguồn nước ở Việt Nam.

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