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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

Modelling of the extractive membrane bioreactor process

Pavasant, Prasert January 1997 (has links)
No description available.
2

The water treatment system at Djupdalen

Guerra Garlito, Rebeca January 2007 (has links)
<p>This is a project about The Water Treatment System at Djupdalen. The leakage water comes to the Water Treatment System from a deposition plant through the land. The leakage water is characterized by a high concentration of nitrogen and the system is based on biological removing of the nitrogen in the water, by nitrifying and denitrifying bacteria. Four different problems are found in the system: 1. High level of nitrogen concentration in the outgoing water of the system. It should be due to the lack of phosphate in the water, that do not let the bacteria to grow. 2. Low temperature during the most part of the year. Nitrifying and denitrifying bacteria are temperature-dependent, that are very slow at low temperatures. 3. High oxygen concentration in one of the anoxic pond, where the denitrification process take place. This oxygen concentration is too high for denitrifying bacteria to work. 4. The nitrification and denitrification bacteria need to be “old” to work efficiently. They need a surface to attach, because if not they flow with the water and they leave the system. And four possible solutions for the system are presented: 1. Phosphate should be added to the system to let bacteria growth. 2. Store the water at a store pond during the winter months and transport it to the system when the temperature is optimum for the bacteria to work. 3. Add carbon matter to improve the carbon oxidation and to low down the oxygen levels at the anoxic ponds. 4. Two options are presented to improve the system, the first one is based on the construction of a dark wavy bottom in the channel system, which will give a surface for bacteria to attaché, it will produce oxygenation in the water, and it will also improve the water temperature; and the second one is based on the addition of panels made of black material, which will give to bacteria a surface to attach, and improve the water temperature.</p>
3

Reuse of Grey water in Peri-urban areas in Dar es Salaam, Tanzania : Minor Field Study

Kocanda, Jakub, Kaguongo, Michael January 2010 (has links)
The purpose of this thesis is to understand and analyse the issues of grey water generation and disposal in peri-urban areas of Dar es Salaam in Tanzania and to propose a suitable solution to which includes designing a treatment system for grey water (water from shower, washing and kitchen). The purification will eliminate the sanitation issues that are brought by exposing untreated grey water to the environment as well save freshwater. This will be implemented with regard to local conditions in Dar es Salaam, Tanzania. Water-borne and vector-borne diseases are mainly brought by untreated grey water, which sadly enough causes thousands of death cases every year in Tanzania. The year between 2004- 2005, 154551 cases of dysentery were reported with 170 deaths. It was also reported, 863488 cases of typhoid with 1167 deaths and last but not least 12923 cases of cholera from with 350 deaths. Deaths that were caused by diarrhoea were also reported, whereby, 90 % of them are children. According to the interviews that were conducted, people would not want to recycle the grey water for example for washing due to socio-cultural context where water is considered dirty even after treatment. They had difficulties in believing that the same dirty grey water can be purified and reused again for various domestic activities. The conducted characterisation of grey water showed the tested grey water has relatively high levels of BOD, basic pH, higher than average values of TSS, relatively low levels of DO, increased salinity and average level of FC. The analyses were performed on the most polluted grey water from every source. The volume of household produced grey water varies strongly, depending on socio-economic situation of the household and type of access to water supply. From estimation, the volume varies approximately between 60 -160 l/day and household for a low income household. Living wall was proposed as grey water treatment system, because of its suitability to the peri-urban settlement and tropical climate. The system consists of concrete boxes placed over each other, filled with inner porous material and planted with plants. The system purifies grey water as it percolates through it and at the same time provides a vertical space for growing plants. The plants for the treatment system were chosen to Typha latifolia and Scirpus species. The plants are growing in Tanzania and are being used for wastewater treatment purposes. The plants are tolerant to increased salinity and can grow in alkaline soil. The cleaning effectiveness of the system was not tested, but only roughly estimated with help of values from a similar treatment system build in Gotland, Sweden. Hence, the reuse of grey water in this geographical location suits best for irrigation in rural and peri-urban areas with potential for agriculture as well as groundwater recharge in the peri-urban and urban areas. Recharging groundwater with treated grey water has a potential to be observed as an indirect and long term reuse of the water as it reconnects in the hydrological cycle.
4

Development of Sustainable Watershed Management Strategies for the Chiang-Chun River Basin

Lee, Mu-Sheng 05 August 2005 (has links)
In the process of pursuing economic growth as the national target for a long time, Taiwan has created an economic miracle but sacrificed ecological environmental sources. With increasing higher living standards, more living space is demanded such that providing clean and green spaces along riverbanks in addition to offering security becomes another important mission. In recent years, the global thinking of sustainable development has demanded more ecological and environmental protection such that efficient management of waters along river, drainage and seacoast will be emphasized tasks of watershed management. The main objective of pollution investigation and quantity estimation in Chiang-Chun River watershed is to effectively comprehend the sources of pollution to assist in establishing the water quality model to be used in simulation. The QUAL2E model developed by the US EPA is used to carried out estimating the carrying capacity of Chiang-Chun River, and drafting pollution control measures and waste reduction strategies so that the objective of improving Chiang-Chun River¡¦s water quality can be achieved. Chiang-Chun River has long been subjected to pollutions from industrial and domestic waste discharges resulting in serious water quality deterioration. Additionally the waste discharge from manufacturing plants along the creek has made the pollution even worse. Hence, various environmental protection authorities have actively promoted the checking and controlling industrial and pig-farming wastewater discharges and established a mechanism encouraging local residents to participate in the watershed pollution prevention and control. These measures will not only alleviate the water pollution in Chiang-Chun River with limited resources but also achieve the purpose of communing local residents and the river. V The livestock wastewater is currently treated in three-stage system including solid-liquid separation, anaerobic treatment and aerobic treatment. With good management, the effluent is expected to meet discharge standards. However, since most pig farmers, who may try to save costs, have not efficiently managed the treatment facility so that the treated effluent does not meet the standards. If directly discharged into surface bodies, the improperly treated effluent will cause serious pollution problems. A natural treatment and water purification system is currently being promoted. If implemented in the three-stage treatment system, the natural system (aquatic treatment system) will achieve energy savings, lower the difficulty to operate the treatment system and reduce the operation and maintenance costs. Additionally, effluent quality can be improved such that the possibility of water reuse is also expected. Providing adequate treatment for domestic wastewater requires the construction of sewage system, which is costly and may take a long time to complete. Additionally, since most residents are scattered in the watershed, the construction of conventional sewage system to collect domestic wastewater is not cost-effective. Hence, the natural system, e.g. constructed wetland, is proposed as the major method for treating the wastewater discharged from communities and for achieving water reuse such that multiple-functional benefits can be reached. Additionally, the concept and tasks of water pollution prevention and control can be deeply rooted in the community development so that a community possessing the capability of water self-purification and sustainable application is developed.
5

Reuse of Grey water in Peri-urban areas in Dar es Salaam, Tanzania : Minor Field Study

Kocanda, Jakub, Kaguongo, Michael January 2010 (has links)
<p>The purpose of this thesis is to understand and analyse the issues of grey water generation and disposal in peri-urban areas of Dar es Salaam in Tanzania and to propose a suitable solution to which includes designing a treatment system for grey water (water from shower, washing and kitchen). The purification will eliminate the sanitation issues that are brought by exposing untreated grey water to the environment as well save freshwater. This will be implemented with regard to local conditions in Dar es Salaam, Tanzania.</p><p>Water-borne and vector-borne diseases are mainly brought by untreated grey water, which sadly enough causes thousands of death cases every year in Tanzania. The year between 2004- 2005, 154551 cases of dysentery were reported with 170 deaths. It was also reported, 863488 cases of typhoid with 1167 deaths and last but not least 12923 cases of cholera from with 350 deaths. Deaths that were caused by diarrhoea were also reported, whereby, 90 % of them are children.</p><p>According to the interviews that were conducted, people would not want to recycle the grey water for example for washing due to socio-cultural context where water is considered dirty even after treatment. They had difficulties in believing that the same dirty grey water can be purified and reused again for various domestic activities.</p><p>The conducted characterisation of grey water showed the tested grey water has relatively high levels of BOD, basic pH, higher than average values of TSS, relatively low levels of DO, increased salinity and average level of FC. The analyses were performed on the most polluted grey water from every source. The volume of household produced grey water varies strongly, depending on socio-economic situation of the household and type of access to water supply. From estimation, the volume varies approximately between 60 -160 l/day and household for a low income household.</p><p>Living wall was proposed as grey water treatment system, because of its suitability to the peri-urban settlement and tropical climate. The system consists of concrete boxes placed over each other, filled with inner porous material and planted with plants. The system purifies grey water as it percolates through it and at the same time provides a vertical space for growing plants.</p><p>The plants for the treatment system were chosen to Typha latifolia and Scirpus species. The plants are growing in Tanzania and are being used for wastewater treatment purposes. The plants are tolerant to increased salinity and can grow in alkaline soil.</p><p>The cleaning effectiveness of the system was not tested, but only roughly estimated with help of values from a similar treatment system build in Gotland, Sweden.</p><p>Hence, the reuse of grey water in this geographical location suits best for irrigation in rural and peri-urban areas with potential for agriculture as well as groundwater recharge in the peri-urban and urban areas. Recharging groundwater with treated grey water has a potential to be observed as an indirect and long term reuse of the water as it reconnects in the hydrological cycle.</p>
6

The water treatment system at Djupdalen

Guerra Garlito, Rebeca January 2007 (has links)
This is a project about The Water Treatment System at Djupdalen. The leakage water comes to the Water Treatment System from a deposition plant through the land. The leakage water is characterized by a high concentration of nitrogen and the system is based on biological removing of the nitrogen in the water, by nitrifying and denitrifying bacteria. Four different problems are found in the system: 1. High level of nitrogen concentration in the outgoing water of the system. It should be due to the lack of phosphate in the water, that do not let the bacteria to grow. 2. Low temperature during the most part of the year. Nitrifying and denitrifying bacteria are temperature-dependent, that are very slow at low temperatures. 3. High oxygen concentration in one of the anoxic pond, where the denitrification process take place. This oxygen concentration is too high for denitrifying bacteria to work. 4. The nitrification and denitrification bacteria need to be “old” to work efficiently. They need a surface to attach, because if not they flow with the water and they leave the system. And four possible solutions for the system are presented: 1. Phosphate should be added to the system to let bacteria growth. 2. Store the water at a store pond during the winter months and transport it to the system when the temperature is optimum for the bacteria to work. 3. Add carbon matter to improve the carbon oxidation and to low down the oxygen levels at the anoxic ponds. 4. Two options are presented to improve the system, the first one is based on the construction of a dark wavy bottom in the channel system, which will give a surface for bacteria to attaché, it will produce oxygenation in the water, and it will also improve the water temperature; and the second one is based on the addition of panels made of black material, which will give to bacteria a surface to attach, and improve the water temperature.
7

EFFECTS OF SOLIDS RETENTION TIME ON THE TREATMENT OF SYNTHETIC WASTEWATER USING A MEMBRANE BIOREACTOR

MACOMBER, JEFF RAYMOND 11 October 2001 (has links)
No description available.
8

Remediation Of Polychlorinated Biphenyl (pcb) Contaminated Building Materials Using Non-metal And Activated Metal Treatment Systems

Legron-Rodriguez, Tamra 01 January 2013 (has links)
PCBs are recalcitrant compounds of no known natural origin that persist in the environment despite their ban by the United States Environmental Protection Agency in 1979 due to negative health effects. Transport of PCBs from elastic sealants into concrete, brick, and granite structures has resulted in the need for a technology capable of removing these PCBs from the materials. This research investigated the use of a nonmetal treatment system (NMTS) and an activated metal treatment system (AMTS) for the remediation and degradation of PCBs from concrete, brick, and granite affixed with PCB-laden caulking. The adsorption of PCBs onto the components of concrete and the feasibility of ethanol washing were also investigated. NMTS is a sorbent paste containing ethanol, acetic acid, and fillers that was developed at the University of Central Florida Environmental Chemistry Laboratory for the in situ remediation of PCBs. Combining NMTS with magnesium results in an activated treatment system used for reductive dechlorination of PCBs. NMTS was applied to laboratory-prepared concrete as well as field samples by direct contact as well as by a novel sock-type delivery. The remediation of PCBs from field samples using NMTS and AMTS resulted in a 33-98% reduction for concrete, a 65-70% reduction for brick, and an 89% reduction in PCB concentration for granite. The limit of NMTS for absorption of Aroclor 1254 was found to be roughly 22,000 mg Aroclor 1254 per kg of treatment system or greater. The activated treatment system resulted in a 94% or greater degradation of PCBs after seven days with the majority of degradation occurring in the first 24 hours. The adsorption of PCBs to individual concrete components (hydrated cement, sand, crushed limestone, and crushed granite) was found to follow the Freundlich isotherm model with greater adsorption to crushed limestone and crushed granite compared to hydrated cement and iv sand. Ethanol washing was shown to decrease the concentration of laboratory-prepared concrete by 68% and the concentration of PCBs in the ethanol wash were reduced by 77% via degradation with an activated magnesium system.
9

The social ecology of alcohol and drug treatment : Client experiences in context

Storbjörk, Jessica January 2006 (has links)
The purpose of this thesis is to study how individuals with alcohol and drug problems come to treatment – who is in treatment and who is not? It further studies the goal and role of treatment according to different groups – clients, staff and politicians. How can we understand clients’ experiences in a context? The main data is from the Women and men in Swedish alcohol and drug treatment-study, with a representative sample of clients as well as complementary data on the views of staff and the general population. The thesis comprises four related papers: (1) explores who is in treatment and who is not by analysing the client and the general population samples; (2) studies reasons for coming to treatment among clients by focussing on self-choice in relation to informal, formal, and legal social pressures to seek treatment; (3) investigates alcohol and drug related events among misusers and the role of these events in treatment entry, and in relation to level of marginalization of the clients; (4) analyses motives for and conflicts surrounding changes in the treatment system on an organizational level. The thesis reveals that clients in treatment are marginalized (regarding housing, work, family, etc.). At treatment entry, clients report self-choice as well as a range of pressures to seek treatment as reasons for coming. The events are influential in treatment seeking, especially events and pressures in relation to significant others. In addition, it is shown that changes in the treatment system are not only driven with the interests of the clients in mind. Professional struggles, economic cuts, and coincidences are of importance. It is shown that different actors have competing as well as compatible and matching views on the goals of treatment. Finally, some notable changes in the treatment system are discussed.
10

The social ecology of alcohol and drug treatment : Client experiences in context

Storbjörk, Jessica January 2006 (has links)
<p>The purpose of this thesis is to study how individuals with alcohol and drug problems come to treatment – who is in treatment and who is not? It further studies the goal and role of treatment according to different groups – clients, staff and politicians. How can we understand clients’ experiences in a context?</p><p>The main data is from the Women and men in Swedish alcohol and drug treatment-study, with a representative sample of clients as well as complementary data on the views of staff and the general population.</p><p>The thesis comprises four related papers: (1) explores who is in treatment and who is not by analysing the client and the general population samples; (2) studies reasons for coming to treatment among clients by focussing on self-choice in relation to informal, formal, and legal social pressures to seek treatment; (3) investigates alcohol and drug related events among misusers and the role of these events in treatment entry, and in relation to level of marginalization of the clients; (4) analyses motives for and conflicts surrounding changes in the treatment system on an organizational level.</p><p>The thesis reveals that clients in treatment are marginalized (regarding housing, work, family, etc.). At treatment entry, clients report self-choice as well as a range of pressures to seek treatment as reasons for coming. The events are influential in treatment seeking, especially events and pressures in relation to significant others. In addition, it is shown that changes in the treatment system are not only driven with the interests of the clients in mind. Professional struggles, economic cuts, and coincidences are of importance. It is shown that different actors have competing as well as compatible and matching views on the goals of treatment. Finally, some notable changes in the treatment system are discussed.</p>

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