Spelling suggestions: "subject:"solar disinfection"" "subject:"polar disinfection""
11 |
AvaliaÃÃo do Processo de DesinfecÃÃo Solar (SODIS) e de sua Viabilidade Social no Estado do Cearà / Solar Disinfection Evaluation and its Social Viability at State of CearÃ, BrazilMarcio Pessoa Botto 14 August 2006 (has links)
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / Apesar da importÃncia do saneamento ambiental para o bem-estar do homem e para a conservaÃÃo dos recursos naturais, uma grande parcela da populaÃÃo mundial nÃo tem acesso aos serviÃos bÃsicos de saneamento. Uma tÃcnica caseira que vem sendo estudada e aplicada em paÃses em desenvolvimento, como uma tecnologia segura para o tratamento microbiolÃgico de Ãgua à a desinfecÃÃo solar, SODIS. Este mÃtodo utiliza apenas o sol e garrafas PET como insumo. Atualmente, cerca de um milhÃo de pessoas utiliza regularmente o SODIS em 20 diferentes paÃses. O presente estudo avaliou a eficiÃncia de inativaÃÃo de coliformes termotolerantes segundo o efeito da aerobiose, por meio da agitaÃÃo manual das garrafas e da utilizaÃÃo de diferentes superfÃcies de exposiÃÃo sob as condiÃÃes climÃticas do Estado do CearÃ, bem como a viabilidade social deste mÃtodo em quatro comunidades inseridas em cenÃrios distintos (rural, litorÃno e urbano). Para tanto, compararam-se amostras agitadas e nÃo agitadas, e amostras expostas sobre superfÃcies distintas: concreto pintado de branco, concreto pintado de preto, telha de barro, telha de amianto e bacias de alumÃnio. Para o estudo da viabilidade social, foram aplicados questionÃrios aos usuÃrios do mÃtodo e analisadas amostras da Ãgua bruta e tratada pelo mÃtodo SODIS. Verificou-se que apesar da agitaÃÃo aferir uma concentraÃÃo de 0,75mg/L a mais de OD nas amostras agitadas, esse efeito nÃo foi capaz de aumentar significativamente a eficiÃncia de inativaÃÃo para essas amostras. O decaimento mÃdio bacteriano das amostras agitadas foi 1,10 vezes maior comparado Ãs amostras nÃo agitadas. Os dados obtidos na etapa de superfÃcie indicaram que tambÃm nÃo hà diferenÃa significativa (teste T de Student, nivel de confianÃa 0,05) de inativaÃÃo em expor as garrafas sobre qualquer uma das superfÃcies pesquisadas. O decaimento mÃdio bacteriano foi de: 0,3049h-1, 0,2624h-1, 0,3152h-1, 0,2747h-1, 0,2874h-1, respectivamente, para as amostras sobre o concreto pintado de branco, concreto pintado de preto, telha de amianto, telha de barro e bacia de alumÃnio. A mÃxima temperatura da Ãgua foi de 44ÂC e ainda assim obteve-se mais de 99,99% de remoÃÃo de coliformes termotolerantes em todos os ensaios. Em 67% dos ensaios, o SODIS foi capaz de inativar completamente concentraÃÃes de coliformes termotolerantes acima de 105 NMP.100mL-1 durante as seis horas de exposiÃÃo. O estudo de campo mostrou que o SODIS melhorou a qualidade microbiolÃgica da Ãgua das quatro comunidades pesquisadas. No entanto, a permanÃncia e em alguns casos a proliferaÃÃo do indicador foi verificado quando os usuÃrios expuseram as garrafas em locais sombreados. O SODIS foi bem aceito nas comunidades rurais e litorÃneas, atingindo nÃveis de aceitaÃÃo acima de 45%, se comparado aos da comunidade urbana, com apenas 8%. AlÃm da grande aceitaÃÃo do mÃtodo, mais de 80% dos usuÃrios responderam que iriam continuar a usar o SODIS. / Despite the importance of sanitation for well-being of the mankind and the natural resources conservation, still today a large number of people do not have access to wastewater system neither to public water supply. One technique which has being studied and applied in developing countries as a safe household water treatment method is solar disinfection, SODIS. The only two elements demanded to this method are PET bottles and the sun. Nowadays, around one million people use SODIS regularly in 20 different countries. This study evaluated the feacal coliform bacteria inactivation efficiency according to the effect of bottlesâ agitation and the use of differents exposition surfaces under of State of Cearà climatic conditions, as well as SODIS social viability in four communities at distinct geographical location (peri-urban, rural and coastal). To achieve this, agitated and non-agitated samples and five diferrents surfaces: concrete spotted in white color, concrete spotted in black color, abobe roofing tile, asbestos roofing tile and aluminum basins were investigated. To evaluate social acceptability, questionnaires had been applied to all users SODIS and raw water and treated water by SODIS were analyzed. It was verified that despite the agitation surveying a concentration more than 0,75mg/L of OD in the agitated samples, this effect was not capable to increase significantly the inactivation efficiency in these samples. The mean decay constant for bacterial population in agitated bottles was found to be a factor of 1.10 higher than in non-agitated bottles. The surface investigation indicated that no significant difference (paired StudentÂs T-test at P=0,05 significance level of log10 transformed data) in inactivating feacal coliforms by exposing the bottles over the five surfaces examined were observed. The mean decay constant for bacterial population was: 0,3049h-1, 0,2624h-1, 0,3152h-1, 0,2747h-1, 0,2874h-1, respectively for the sample exposed over concrete spotted in white color, concrete spotted in black color, abobe roofing tile, asbestos roofing tile and aluminum basins. The maximum water temperature reached was 44ÂC and still thus, it was obtained reduction more than 99.99% of feacal coliforms. In 67% of the assays, SODIS was capable to completely inactivate concentrations of feacal coliforms above 105 NMP.100mL-1 within six hours of exposition. The field study had shown that SODIS improved the microbiological water quality in the four communities. However, the permanence and in some cases the increase of feacal coliforms was verified when the users exposed the bottles in shaded areas. SODIS was well received in rural and coastal communities reaching acceptance levels over than 45%, compared to urban community, with only 8%. Beyond the great acceptance of the method, over 80% of the users answered that they would continue to use SODIS.
|
12 |
Desinfec??o solar de ?gua para comunidades de baixa rendaFelix, Lorna Falc?o 11 August 2010 (has links)
Made available in DSpace on 2014-12-17T14:58:02Z (GMT). No. of bitstreams: 1
LornaFF_DISSERT.pdf: 1583266 bytes, checksum: fdceb25a7df6f0f8c5f14e1a6f473aa6 (MD5)
Previous issue date: 2010-08-11 / The use of solar energy for water disinfection, and is accessible to disadvantaged communities because of its low cost, has the advantage of using disposable materials such as bottles of polyethylene terephthalate (PET). We present a study that used two methods of disinfection: the methodology proposed by the project Solar Water Disinfection (SODIS), which consisted of water disinfection by solar radiation and temperature and the methodology which the temperature of the water for disinfection. In both, we seek to eliminate microorganisms that cause serious diseases such as dysentery, typhoid, cholera, etc. Water samples were collected in the community of Bass, where the population has low income and the incidence of waterborne diseases is high. The experiments were divided into two stages. In step 1 we studied the feasibility of disinfection and in step 2 the feasibility of the pilot plant to obtain adequate levels of disinfection temperatures desired. The results showed the efficiency of the disinfection process, reaching an average of 80 to 100% death of microorganisms, but regrowth was observed in some samples. Finally on the good results of stage 1, is designed and built and tested in an experimental pilot plant, which has shown to be feasible to promote water disinfection through the use of solar energy. The water after treatment is in accordance with the limits established by Brazilian legislation for clean water, maintaining a positive performance for the disinfection and acceptable levels of bacterial regrowth / A utiliza??o da energia solar para desinfec??o de ?gua, al?m de ser acess?vel para comunidades menos favorecidas pelo seu baixo custo, tem a vantagem de utilizar materiais descart?veis como garrafas de politereftalato de etileno (PET). Apresenta-se um estudo que utilizou duas metodologias de desinfec??o: a metodologia proposta pelo projeto Solar Water Disinfection (SODIS) que consistiu na desinfec??o da ?gua pela radia??o solar e pela temperatura e a metodologia que utilizou a temperatura da ?gua para a desinfec??o. Em ambas, busca-se eliminar microrganismos causadores de s?rias doen?as como disenterias, febre tif?ide, c?lera, etc. As amostras de ?gua foram coletadas na comunidade do Robalo, local onde a popula??o possui baixa renda e a incid?ncia de doen?as de veicula??o h?drica ? alta. Os experimentos foram divididos em duas etapas: Na etapa 1 estudou-se a viabilidade da desinfec??o e na etapa 2 a viabilidade da planta piloto na obten??o de n?veis de temperaturas adequados ? desinfec??o pretendida. Os resultados obtidos mostraram a efici?ncia do processo de desinfec??o, atingindo uma m?dia de 80 a 100% de morte dos microorganismos, por?m foi observado recrescimento em algumas amostras. Finalmente, diante dos bons resultados da etapa 1, projetou-se, construiu-se e ensaiou-se uma planta piloto experimental, que demonstrou-se vi?vel para promover a desinfec??o de ?gua atrav?s do uso da energia solar. A ?gua, ap?s o tratamento, encontra-se de acordo com os limites estabelecidos pela legisla??o brasileira para ?gua tratada, mantendo um desempenho favor?vel na desinfec??o e ?ndices aceit?veis do recrescimento bacteriano
|
13 |
The effect of solar irradiated vibrio cholerae on the immunochemistry of dendritic cellsSsemakalu, Cano Cornelius 24 August 2015 (has links)
D. Tech. (Department of Chemistry, Faculty of Applied and Computer Sciences), Vaal University of Technology. / Cholera is a waterborne disease caused by toxigenic strains of Vibrio cholerae. The spread of cholera in developing countries has largely been imputed to the unavailability of proper water treatment and sanitary infrastructure as well as poor hygiene. In order to prevent the contraction and spread of cholera the use of solar disinfection (SODIS) to treat water in waterborne endemic communities has been recommended by the World Health Organization (WHO). SODIS is a water sterilizing method that relies on natural sunlight to improve the microbiological quality of water. During SODIS the culturability of the water contaminating microorganisms is inactivated by the ultraviolet component of solar radiation. The success of SODIS treatment of water in alleviating the risks associated with the contraction of waterborne diseases such as cholera has been attributed to the effectiveness, with which the water is treated, simple application as well as low cost of materials required. Currently SODIS research has been dominated by studies geared towards understanding how the microbial inactivation occurs, enhancement of the disinfection process and health impact assessments. However, little to no research has been directed towards exploring the role played by the immune system following the consumption of the solar irradiated water pathogens such as V. cholerae. SODIS of microorganisms in water results in immunologically important microbial states and components that could induce an immune reaction or response. In view of the role of dendritic cells in shaping an immune response, the effect that solar irradiated V. cholerae in water has on the immunochemistry of the dendritic cells in vitro was investigated. Prior to the stimulation of the dendritic cells with the solar irradiated cultures of V. cholerae, the first objective required an evaluation on the impact that solar irradiation has on the production and secretion of the cholera toxin by V. cholerae in water. The results from this evaluation showed that solar ultraviolet radiation was incapable of inducing the secretion of the cholera toxin. Furthermore, there was extensive DNA degradation in the solar irradiated cultures of V. cholerae. The second objective was to investigate the ability for solar irradiated cultures of V. cholerae in water to induce the phenotypic maturation of immature dendritic cells in vitro. In order to achieve this objective, solar and non-solar irradiated, chemically/ heat inactivated and phosphate buffered saline (PBS) prepared cultures of V. cholerae as well as lipopolysaccharide (LPS) and cholera toxin-β (CTB) subunit were each used to stimulate immature dendritic cells. After 48 hours of stimulation the dendritic cells were assessed for the expression of CD54, CD80, CD83, CD86, MHC-I and MHC-II on their cell membrane. The results showed an increase in the expression of all the maturation phenotypic markers with CD54, CD86 and MHC-I being the most prominent ones on the surface of the dendritic cells stimulated with solar irradiated cultures of V. cholerae. The third objective was to assess the profile of the cytokines and chemokines secreted by the dendritic cells following their stimulation with solar and non-solar irradiated, chemically/heat inactivated and PBS prepared cultures of V. cholerae as well as LPS and CTB subunit. After 48 hours of dendritic cell stimulation the tissue culture media from each treatment was quantitatively and qualitatively analysed for the presence of interleukin (IL)-1α, IL-1β, IL-6, IL-7, IL-10, IL-12p40, IL-12p70, IL-15, IL-23, IL-27, macrophage inflammatory protein (MIP)-1α, MIP-1β, MIP-2, Regulated on Activation, Normal T cell Expressed and Secreted (RANTES) and tumor necrosis factor (TNF)-α. The analysis revealed that solar irradiated cultures of V. cholerae induced dendritic cells to secrete significant levels of pro-inflammatory cytokines in comparison to the unstimulated dendritic cells. Furthermore the profile of the cytokines and chemokines secreted by the dendritic cells in response to the solar irradiated cultures of V. cholerae in water was similar to that required to induce a T- helper (Th) Th2 immune response. The fourth objective was to assess the expression of the toll like receptor (tlr) genes by the dendritic cells following their stimulation with solar and non-solar irradiated, chemically/heat inactivated and PBS prepared cultures of V. cholerae as well as LPS and CTB subunit. After 48 hours of stimulation total RNA was extracted from the dendritic cells and subjected to real time quantitative polymerase chain reaction (RT qPCR) assay for tlr 1, 2, 3, 4, 5, 6, 9, 11, 12 and 13. The results showed no significant increase or decrease in the expression of most tlr genes in comparison to the unstimulated dendritic cells. This observation is synonyms with dendritic cell maturation. Taken together these findings show that solar irradiated cultures of V. cholerae were able to induce the maturation of immature dendritic cells in vitro. Furthermore dendritic cells stimulated with solar irradiated cultures of V. cholerae produced pro-inflammatory cytokines and chemokines. The results from this study suggests that the consumption of SODIS treated could provide immunological benefits.
|
14 |
Designing a Sustainable System for Water Supply and Sanitation in Rural Peru / Diseño de un Sistema Sostenible de Agua Potable y Saneamiento en Zonas Rurales de PeruPersson, Ida Maria Linnéa January 2009 (has links)
<p>Given the tremendous importance of water supply and sanitation (WSS) on health and welfare, the purpose of this thesis was to suggest a design of a sustainable WSS system for a rural village in the sub-Andean Amazon of Northern Peru. WSS planning and intervention in the developing world have traditionally been characterized by large failures, and to understand the related problems, this work was initiated with a literature review on the topic. The review resulted in the development of a planning support, containing eight stages ranging from project identification to project realization. Within this thesis, the first four stages were implemented, including an in-field WSS situation assessment and a screening of suitable technical options.</p><p>The in-field assessment contained a general fact collection, an inventory where about a fifth of the households in the village was visited and interviewed, and a water quality analysis. An analysis of the assessment findings resulted in the identification of the WSS components requiring intervention. Thereafter followed a screening of suitable technologies, and based on the results from the analysis, a selection of interesting options was done. Selected options were reviewed and evaluated according to a set of sustainability criteria.</p><p>A majority of the households in the village had standpipes on their premises, delivering untreated water from an unprotected creek outside the village. Apart from surface water, rainwater and water from an open spring were also used in the village. The water analysis revealed that surface water contained elevated levels of bacteria, whereas the spring water was clean. Contaminated water remained contaminated after household treatment (boiling), indicative of poor handling. Water treatment with solar disinfection (SODIS) proved to be effective. The sanitary situation was not satisfactory; almost all households had unimproved pit latrines that could not ensure a hygienic separation of excreta, and open defecation was also practiced. Greywater, resulting from showering and cloth-washing under the standpipe, was at best diverted away from the premises by small drains, but often not managed at all. Stormwater created unhygienic conditions on both private premises and in communal areas during the rainy season; the management situation was similar to that of greywater. Solid waste was not officially managed and even though many of the households had designated a collection site, waste was commonly seen all over the premises.</p><p>The selected technologies were mainly inexpensive such that could be constructed, operated and managed by the community itself. From the assessment it also became clear that the WSS situation could be considerably improved by behavior change. Following the developed planning support; with the finalization of this thesis, the next step would be to present the results from the screening and evaluation of technologies to the villagers, for them to decide which options to proceed with.</p> / <p>Debido a la gran importancia del agua potable y saneamiento (APS) para la salud y el bienestar, el objetivo de este proyecto fue proponer un sistema APS, adecuado y sostenible, para una aldea rural en la selva Amazónica en el norte de Perú. Tradicionalmente, la planificación y el diseño de APS en el mundo en desarrollo han sido caracterizados por fallos grandes, y para comprender los problemas, este trabajo comenzó con un estudio amplio sobre el tema. El estudio resultó en un apoyo de planificación, que contiene ocho etapas que van desde la identificación de un proyecto a la realización del proyecto, y fue empleado para la orientación en el trabajo posterior. Dentro de esta tesis, las primeras cuatro etapas se llevaron a cabo, incluyendo una evaluación de la situación APS en campo y un examen de las opciones técnicas adecuadas.</p><p>El trabajo de campo incluía una colección de datos, un inventario, en el que una quinta parte de los hogares en el pueblo fue visitada y entrevistada, y un análisis del agua. Un análisis de los resultados del trabajo de campo resultó en la identificación de los componentes de APS que requieren una intervención. Después siguió un examen de tecnologías adecuadas, y con base en los resultados del análisis se hizo una selección de opciones interesantes. Las opciones seleccionadas fueron revisadas y evaluadas de acuerdo a un conjunto de criterios de sostenibilidad.</p><p>En la mayoría de los hogares del pueblo había una pileta en sus parcelas, entregando agua no tratada de una quebrada sin protección, a fuera del pueblo. Aparte de las aguas superficiales, habían aguas de lluvia y de una fuente abierta. El análisis del agua mostraba niveles elevados de contaminación bacteriológica en las aguas superficiales, mientras que el agua de la fuente abierta era limpia. El tratamiento del agua con la desinfección solar fue demostrado ser eficaz. La situación sanitaria no era satisfactoria – casi todos los hogares tenían letrinas de foso, que no podían asegurar una separación higiénica de la excreta, y la práctica de defecación al aire libre también se veía. Aguas grises, resultante del lavado de ropa y el baño de personas debajo de la pileta, en el mejor de los casos estaban desviando de las parcelas, pero a menudo no estaban tratando. Durante las épocas de lluvia, había bastantes problemas con el agua de escorrentía, creando las condiciones antihigiénicas, y el manejo de la situación era la misma que la de las aguas grises. Los residuos sólidos no estaban oficialmente manejados y aunque muchos de los hogares habían designado un lugar especial en el patio para su recolección, eran comúnmente vistos en todas las parcelas.</p><p>Las tecnologías seleccionadas fueron tales que podrían ser financiadas, construidas, operadas y administradas por la propia comunidad. La evaluación reveló que la situación también podría mejorar considerablemente con un cambio de conducta. A la finalización de este proyecto, la siguiente etapa, de acuerdo con el apoyo de la planificación, sería devolver la evaluación de las opciones seleccionadas a los habitantes del pueblo, y dejar a ellos decidan con cuales opciones quieren proceder.</p> / <p>Dricksvatten och sanitet (DVS) är extremt viktigt för hälsa och välfärd, både för individen och för samhället i stort. Syftet med detta examensarbete var därför att föreslå en utformning av ett hållbart DVS-system för en by i sub-andinska Amazonas i norra Peru. DVS-planering och -projektering har traditionellt karakteriserats utav stora misslyckanden, och för att förstå denna problematik så inleddes arbetet med en översiktlig studie i ämnet. Detta resulterade i att ett vägledande planeringsstöd utvecklades, bestående av åtta steg som sträcker sig från problemidentifikation till projektrealisering. Inom ramen för detta arbete ingick de fyra första stegen, vilket inkluderade en fältundersökning av DVS-situationen i byn och en genomgång av lämpliga tekniska alternativ.</p><p>Fältundersökningen innefattande en allmän faktainsamling, en inventering där en femtedel av byns hushåll besöktes och intervjuades, och en vattenanalys. Resultaten från fältundersökning sammanfattades och ett antal DVS-punkter identifierades som i behov av åtgärder. I teknikgenomgången användes resultaten från fältundersökning som grund för urvalet av intressanta alternativ, vilka sedan utvärderades utifrån en uppsättning hållbarhetskriterier.</p><p>Majoriteten av hushållen i byn hade en vattenkran på sina ägor, och vattnet levererades obehandlat från ett oskyddat vattendrag utanför byn. Förutom ytvatten så använde man även regnvatten och vatten från en öppen källa. Vattenanalysen visade att ytvattnet var starkt förorenat av bakterier, medan källvattnet visade sig vara rent. Förorenat vatten förblev förorenat även efter att hushållen behandlat det (genom kokning), vilket tyder på dålig efterhantering. Soldisinfektion (SODIS) visade sig vara en effektiv reningsmetod. Den sanitära situationen var otillfredsställande – nästan alla hushåll använde sig av oförbättrade grävda latriner och även tarmtömning i det fria praktiserades. BDT-vatten, från dusch och tvätt under vattenkranen, var som bäst avlett från ägorna med enkla fåror, men oftast inte alls hanterat. Under regnperioden orsakade dagvatten ohygieniska förhållanden och hanteringen var liknande den för BDT-vattnet. Det fanns ingen officiell sophantering och även om många hushåll avsatt en speciell plats på gården för insamling så var nedskräpningen omfattande.</p><p>Utvalda tekniker var främst sådana som skulle kunna bekostas, konstrueras, drivas och skötas av samhället själv. I fältundersökningen framkom det också att situationen skulle kunna förbättras avsevärt genom beteendeändringar. I och med avslutningen av detta arbete är nästa steg att, i enlighet med planeringsstödet, presentera resultaten från utvärderingen av de tekniska alternativen för invånarna i byn, och låta dem besluta om vilka som de vill gå vidare med.</p>
|
15 |
Designing a Sustainable System for Water Supply and Sanitation in Rural Peru / Diseño de un Sistema Sostenible de Agua Potable y Saneamiento en Zonas Rurales de PeruPersson, Ida Maria Linnéa January 2009 (has links)
Given the tremendous importance of water supply and sanitation (WSS) on health and welfare, the purpose of this thesis was to suggest a design of a sustainable WSS system for a rural village in the sub-Andean Amazon of Northern Peru. WSS planning and intervention in the developing world have traditionally been characterized by large failures, and to understand the related problems, this work was initiated with a literature review on the topic. The review resulted in the development of a planning support, containing eight stages ranging from project identification to project realization. Within this thesis, the first four stages were implemented, including an in-field WSS situation assessment and a screening of suitable technical options. The in-field assessment contained a general fact collection, an inventory where about a fifth of the households in the village was visited and interviewed, and a water quality analysis. An analysis of the assessment findings resulted in the identification of the WSS components requiring intervention. Thereafter followed a screening of suitable technologies, and based on the results from the analysis, a selection of interesting options was done. Selected options were reviewed and evaluated according to a set of sustainability criteria. A majority of the households in the village had standpipes on their premises, delivering untreated water from an unprotected creek outside the village. Apart from surface water, rainwater and water from an open spring were also used in the village. The water analysis revealed that surface water contained elevated levels of bacteria, whereas the spring water was clean. Contaminated water remained contaminated after household treatment (boiling), indicative of poor handling. Water treatment with solar disinfection (SODIS) proved to be effective. The sanitary situation was not satisfactory; almost all households had unimproved pit latrines that could not ensure a hygienic separation of excreta, and open defecation was also practiced. Greywater, resulting from showering and cloth-washing under the standpipe, was at best diverted away from the premises by small drains, but often not managed at all. Stormwater created unhygienic conditions on both private premises and in communal areas during the rainy season; the management situation was similar to that of greywater. Solid waste was not officially managed and even though many of the households had designated a collection site, waste was commonly seen all over the premises. The selected technologies were mainly inexpensive such that could be constructed, operated and managed by the community itself. From the assessment it also became clear that the WSS situation could be considerably improved by behavior change. Following the developed planning support; with the finalization of this thesis, the next step would be to present the results from the screening and evaluation of technologies to the villagers, for them to decide which options to proceed with. / Debido a la gran importancia del agua potable y saneamiento (APS) para la salud y el bienestar, el objetivo de este proyecto fue proponer un sistema APS, adecuado y sostenible, para una aldea rural en la selva Amazónica en el norte de Perú. Tradicionalmente, la planificación y el diseño de APS en el mundo en desarrollo han sido caracterizados por fallos grandes, y para comprender los problemas, este trabajo comenzó con un estudio amplio sobre el tema. El estudio resultó en un apoyo de planificación, que contiene ocho etapas que van desde la identificación de un proyecto a la realización del proyecto, y fue empleado para la orientación en el trabajo posterior. Dentro de esta tesis, las primeras cuatro etapas se llevaron a cabo, incluyendo una evaluación de la situación APS en campo y un examen de las opciones técnicas adecuadas. El trabajo de campo incluía una colección de datos, un inventario, en el que una quinta parte de los hogares en el pueblo fue visitada y entrevistada, y un análisis del agua. Un análisis de los resultados del trabajo de campo resultó en la identificación de los componentes de APS que requieren una intervención. Después siguió un examen de tecnologías adecuadas, y con base en los resultados del análisis se hizo una selección de opciones interesantes. Las opciones seleccionadas fueron revisadas y evaluadas de acuerdo a un conjunto de criterios de sostenibilidad. En la mayoría de los hogares del pueblo había una pileta en sus parcelas, entregando agua no tratada de una quebrada sin protección, a fuera del pueblo. Aparte de las aguas superficiales, habían aguas de lluvia y de una fuente abierta. El análisis del agua mostraba niveles elevados de contaminación bacteriológica en las aguas superficiales, mientras que el agua de la fuente abierta era limpia. El tratamiento del agua con la desinfección solar fue demostrado ser eficaz. La situación sanitaria no era satisfactoria – casi todos los hogares tenían letrinas de foso, que no podían asegurar una separación higiénica de la excreta, y la práctica de defecación al aire libre también se veía. Aguas grises, resultante del lavado de ropa y el baño de personas debajo de la pileta, en el mejor de los casos estaban desviando de las parcelas, pero a menudo no estaban tratando. Durante las épocas de lluvia, había bastantes problemas con el agua de escorrentía, creando las condiciones antihigiénicas, y el manejo de la situación era la misma que la de las aguas grises. Los residuos sólidos no estaban oficialmente manejados y aunque muchos de los hogares habían designado un lugar especial en el patio para su recolección, eran comúnmente vistos en todas las parcelas. Las tecnologías seleccionadas fueron tales que podrían ser financiadas, construidas, operadas y administradas por la propia comunidad. La evaluación reveló que la situación también podría mejorar considerablemente con un cambio de conducta. A la finalización de este proyecto, la siguiente etapa, de acuerdo con el apoyo de la planificación, sería devolver la evaluación de las opciones seleccionadas a los habitantes del pueblo, y dejar a ellos decidan con cuales opciones quieren proceder. / Dricksvatten och sanitet (DVS) är extremt viktigt för hälsa och välfärd, både för individen och för samhället i stort. Syftet med detta examensarbete var därför att föreslå en utformning av ett hållbart DVS-system för en by i sub-andinska Amazonas i norra Peru. DVS-planering och -projektering har traditionellt karakteriserats utav stora misslyckanden, och för att förstå denna problematik så inleddes arbetet med en översiktlig studie i ämnet. Detta resulterade i att ett vägledande planeringsstöd utvecklades, bestående av åtta steg som sträcker sig från problemidentifikation till projektrealisering. Inom ramen för detta arbete ingick de fyra första stegen, vilket inkluderade en fältundersökning av DVS-situationen i byn och en genomgång av lämpliga tekniska alternativ. Fältundersökningen innefattande en allmän faktainsamling, en inventering där en femtedel av byns hushåll besöktes och intervjuades, och en vattenanalys. Resultaten från fältundersökning sammanfattades och ett antal DVS-punkter identifierades som i behov av åtgärder. I teknikgenomgången användes resultaten från fältundersökning som grund för urvalet av intressanta alternativ, vilka sedan utvärderades utifrån en uppsättning hållbarhetskriterier. Majoriteten av hushållen i byn hade en vattenkran på sina ägor, och vattnet levererades obehandlat från ett oskyddat vattendrag utanför byn. Förutom ytvatten så använde man även regnvatten och vatten från en öppen källa. Vattenanalysen visade att ytvattnet var starkt förorenat av bakterier, medan källvattnet visade sig vara rent. Förorenat vatten förblev förorenat även efter att hushållen behandlat det (genom kokning), vilket tyder på dålig efterhantering. Soldisinfektion (SODIS) visade sig vara en effektiv reningsmetod. Den sanitära situationen var otillfredsställande – nästan alla hushåll använde sig av oförbättrade grävda latriner och även tarmtömning i det fria praktiserades. BDT-vatten, från dusch och tvätt under vattenkranen, var som bäst avlett från ägorna med enkla fåror, men oftast inte alls hanterat. Under regnperioden orsakade dagvatten ohygieniska förhållanden och hanteringen var liknande den för BDT-vattnet. Det fanns ingen officiell sophantering och även om många hushåll avsatt en speciell plats på gården för insamling så var nedskräpningen omfattande. Utvalda tekniker var främst sådana som skulle kunna bekostas, konstrueras, drivas och skötas av samhället själv. I fältundersökningen framkom det också att situationen skulle kunna förbättras avsevärt genom beteendeändringar. I och med avslutningen av detta arbete är nästa steg att, i enlighet med planeringsstödet, presentera resultaten från utvärderingen av de tekniska alternativen för invånarna i byn, och låta dem besluta om vilka som de vill gå vidare med.
|
16 |
Inactivation bactérienne par photocatalyse hétérogène : application à Escherichia Coli / Bacterial inactivation by heterogeneous photocatalysis : applied to Escherichia ColiKacem, Majdi 07 July 2015 (has links)
L’étude présentée dans ce mémoire s’inscrit dans le cadre de la réutilisation des eaux usées traitées par un procédé d’oxydation avancée (AOP), la photocatalyse hétérogène. Ce procédé, couplant le rayonnement UV et l’utilisation d’un photocatalyseur (TiO2) au sein d’un réacteur, est envisagé comme procédé de traitement tertiaire pour la désinfection des effluents dis secondaires. Les expérimentations photocatalytiques ont été réalisées sur une bactérie cible, E.coli. Elles ont été conduites en mode batch puis en mode continu. Les expérimentations en mode batch ont été réalisées sous irradiation contrôlée puis solaire. Les données expérimentales acquises sous irradiation contrôlée ont permis la comparaison des performances bactéricides de différents catalyseurs. Elles ont conduit en parallèle à la définition d’un modèle cinétique représentatif de la capacité bactéricide de chaque média. Les expérimentations solaires ont permis de valider le modèle cinétique sous irradiation solaire puis, d’étudier l’inactivation bactérienne dans un effluent réel. Par ailleurs, le potentiel bactéricide du traitement photocatalytique en régime permanent a été évalué. Le fonctionnement du procédé continu a été parfaitement décrit par un modèle cinétique se basant sur la loi cinétique initialement définie en mode batch. Finalement, l’inactivation d’E.coli a été évaluée par différentes techniques de quantification bactérienne. Cela a permit de mettre en évidence le mécanisme principal d’inactivation par voie photocatalytique, la lyse membranaire et d’apporter des informations sur l’état de viabilité « réel » des bactéries au cours du traitement photocatalytique. / The study presented in this paper is part of the reuse of treated wastewater by advanced oxidation process (AOP), the heterogeneous photocatalysis. This process, coupling the UV radiation and the use of a photocatalyst (TiO2) in a reactor, is envisaged as tertiary treatment process for disinfection of said secondary effluent. Photocatalytic experiments were performed on a target bacterium, E. coli. They were conducted in batch and continuous mode. The experiments in batch mode were performed under controlled irradiation and sunlight. The experimental data obtained under controlled irradiation allowed the comparison of the bactericidal performance of different catalysts. They led in parallel to the definition of a representative kinetic model of the bactericidal capacity of each medium. Solar experiments were used to validate the kinetic model under solar irradiation and then to study the bacterial inactivation in a real effluent. Furthermore, the potential of the photocatalytic bactericidal treatment at steady state was evaluated. The operation of the continuous process has been thoroughly described by a kinetic model based on the kinetic law originally defined in batch mode. Finally, inactivation of E. coli was evaluated by different bacterial quantification techniques. This has made it possible to highlight the main mechanism of the photocatalytic bacterial inactivation, the membrane lysis. It provided information about the "real" state of the bacteria viability during the photocatalytic treatment.
|
17 |
Applications and Acceptance of Solar UV Technologies for Drinking Water Disinfection in Low-Income SettingsMargaret M Busse (11547811) 13 October 2021 (has links)
<p>Access to potable water has been identified as a basic human right, yet it is estimated that 2.2 billion people worldwide do not have access to safely managed drinking water. Many of those without access live in regions of the world with abundant sunlight, which can be utilized both directly and indirectly to disinfect drinking water. Directly it can be used in solar water disinfection (SODIS) applications, and indirectly it can be collected by solar panels to power commercially available UV reactors. Herein, we study the potential for direct and indirect water disinfection technologies to be used and adopted in developing countries, with specific insight into their application in the Dominican Republic and Kenya.</p><p>The amount of available ambient solar UV was both measured and modelled to inform design and modelling of treatment systems, and to understand whether real-time monitoring of ambient UV is required for the operation of systems directly utilizing UV for disinfection. The model both over- and under-predicted measurements of ambient UV, and did so at inconsistent rates, most likely as a result of cloud cover. This indicates that real-time monitoring of ambient UV would most likely be needed for disinfection methods directly using solar UV for inactivation in order to ensure water was always dosed properly.</p><p>The amount of available ambient solar UV was input into a raytracing model (Photopia, LTI Optics) to simulate the amplification of solar spectral irradiance within a continuous-flow compound parabolic collector (CPC). This informed design improvements that allowed for an increase in flow rate through the system, which was supported by field testing of the reactor. Further, two commercial UV reactors, one utilizing a low-pressure (LP) lamp and the other utilizing an LED source, were tested in the lab to verify their ability to inactivate <i>S. typhimurium </i>LT2. The LP-based device outperformed the LED-based device, which was unable to achieve over 2-log<sub>10</sub> units of inactivation under any of the studied conditions.</p><p>A life cycle assessment was conducted to assess the environmental impact of the three studied UV reactors against traditional chlorination and water delivery methods. Chlorine had the lowest impact in every category under all of the studied conditions, but there have been many barriers reported on the lack of adoption of chlorine. So the next lowest impact technology was evaluated at the community scale, which was the LP reactor. Therefore, the LP reactor was installed in study communities in both the Dominican Republic and Kenya. In the Dominican Republic, the systems suffered from a lack of boots on the ground, and faced technical, social, and economic barriers to adoption. In Kenya, the project suffered from similar constraints, that did not allow for project assessment. This work not only addresses the barriers faced in both of these projects, but provides suggestions for improving similar projects in the future.</p>
|
18 |
The effects of solar irradiated Salmonella Typhimurium and campylobacter jejuni on the proliferation and activation of macrophages in vitroChihomvu, Patience 12 1900 (has links)
D. Tech. (Department of Biotechnology, Faculty of Applied and Computer Sciences), Vaal University of Technology. / Salmonella enterica serovar Typhimurium and Campylobacter jejuni are the leading causes of Salmonellosis and Campylobacteriosis that is characterised by gastroenteritis. These waterborne diseases can be easily prevented by home water treatment methods such as solar disinfection (SODIS). The SODIS process involves placing microbiologically unsafe water in clear plastic or glass bottles and exposing them to direct sunlight for approximately six to eight hours. SODIS kills microbes through a combination of DNA-damaging effects of ultraviolet (UV) radiation and thermal inactivation from solar heating. The result is microbiologically safe water. Continuous drinking of SODIS treated water may confer some immunological effects on the consumer. These immunological effects have not been thoroughly explored. Therefore, the objectives of this study were to firstly, characterise the effects of solar irradiation on the viability of S. Typhimurium and C. jejuni; secondly, to determine the cytotoxicity and modulation of cell death of solar irradiated S. Typhimurium and C. jejuni on macrophages. Thirdly, to analyse the chemokine and cytokine profiles of macrophages infected with solar irradiated S. Typhimurium and C. jejuni. Lastly, to analyse the host-cell interactions of macrophages infected with solar-irradiated and non-solar irradiated S. Typhimurium and C. jejuni using a proteomic approach.
In all the experiments, S. Typhimurium and C. jejuni were (i) heat/chemically treated, (ii) solar and non-solar irradiated for 4 and 8 hours. A murine macrophage cell line RAW264.7 was co-cultured with the differentially treated bacteria species for 3 and 24 hours. Appropriate controls were included.
The impact of solar irradiated S. Typhimurium and C. jejuni on intracellular growth, proliferation, cytotoxicity, and apoptosis on macrophages was assessed. Intracellular growth of the both bacterial species was assessed with the gentamicin protection assay, and cytotoxicity was determined by Lactate Dehydrogenase Assay (LDH). The macrophages treated with solar irradiated S. Typhimurium and C. jejuni showed no intracellular growth after 48 hours post-infection. However, the non-irradiated S. Typhimurium survived within the macrophages and were highly toxic to the macrophages (average cytotoxicity of 91%±32). The non-solar irradiated C. jejuni were metabolically active but non-culturable, whereas the solar-irradiated C. jejuni was metabolically inactive. Thus, solar irradiated C. jejuni showed a lower percentage cytotoxicity (2.57% ± 0.32%) in comparison to non-solar irradiated C. jejuni at 24 hours post-infection (p.i.) (30.28% ± 0.05%). Flow cytometric analysis showed that the non-irradiated S. Typhimurium brought about a statistically significant increase in the percentage of necrotic cells (48% ± 2.99%), whereas bacteria irradiated for 8 hours produced a lower percentage of necrotic cells (25% ± 5.87%). The heat/chemical attenuated samples had the lowest percentage of necrotic cells (21.15% ± 5.36%) at 24 h p.i. Macrophages treated with solar irradiated and non-solar irradiated C. jejuni did not induce necrosis, but apoptotic cell death. At 24 h p.i., the highest proportion of apoptotic cell death was observed in macrophages treated with non-solar irradiated C. jejuni whereas the solar irradiated C. jejuni showed a lower percentage of apoptotic cell death. Therefore, there is great possibility that S. Typhimurium and C. jejuni could become avirulent after SODIS treatment and this could prevent gastroenteritis in consumers of SODIS-treated water.
The activation of macrophages infected with solar irradiated S. Typhimurium and C. jejuni was also assessed in this study. The production of nitric oxide (NO) was determined using the Greiss Reagent Assay, whereas the production of chemokines, cytokines, and growth stimulating factors by the RAW264.7 cells in vitro was measured using the Luminex 200. The results showed that both solar and non-solar irradiated S. Typhimurium inhibited the production of nitric oxide in the RAW264.7 cells. The heat/chemically attenuated S. Typhimurium induced a significant increase (p<0.0.5) in the production of NO2− in the macrophages when compared to the unstimulated RAW264.7. The chemokine and cytokine levels produced by the macrophages were similar in the solar inactivated S. Typhimurium and the live untreated S. Typhimurium. However, macrophages treated with heat/chemically attenuated S. Typhimurium showed an anti-inflammatory response by inhibiting the production of pro-inflammatory cytokines such as IL-1, IL-1, IL-2, IL-6, and IL-17 in macrophages. The macrophages treated with solar and non-solar irradiated C. jejuni possibly produced an anti-inflammatory effect since the amount of pro-inflammatory cytokines in the samples was significantly reduced during the late infection period (24 h p.i.).
This study also analysed the proteomic profiles of macrophages treated with LPS, non-solar irradiated, solar irradiated, heat/ chemical inactivated S. Typhimurium, and C. jejuni. This was carried out using SWATH-mass spectrophotometry-based proteomics. Proteins were extracted from infected macrophages after 24 hours p.i. HILIC-based sample clean-up and digestion, DDA LCMS-MS (spectral library), SWATH LCMS-MS, and data processing were carried out. A total of 15,077 peptides matching to 2,778 proteins were identified at 1% FDR with numerous differentially expressed proteins (DEPs) detected in macrophages treated with lipopolysaccharide (LPS), non-solar irradiated C. jejuni (NS), heat-attenuated C. jejuni (HA) and 4h-solar irradiated (SI4) and 8h-solar irradiated (SI8) C. jejuni, respectively. Pathway analysis revealed that most of the upregulated proteins in macrophages treated with solar irradiated C. jejuni were involved in oxidation-reduction processes, endoplasmic reticulum stress, transport, antigen processing and presentation of exogenous peptide antigens via MHC class I (TAP-dependant) and ATP-biosynthetic processes. The KEGG-pathways also revealed the roles of some upregulated proteins in lysosomal and phagosome pathways. In conclusion, our results revealed that there is coordinated up-regulation of MHC-I processing pathways occurred at 24 h p.i. It is likely that proteins from solar irradiated C. jejuni may undergo proteasomal degradation, and the peptides are transported to the endoplasmic reticulum (ER) and loaded onto MHC-I molecules. Peptide loading results in class I complexes consolidation and transit to the cell surface where antigens can be presented to circulating CD8 + T cells. Additionally, solar irradiated C. jejuni also undergoes degradation in the phagosome. The phagosome has the potential to create antigens that can be expressed on the cell surface of macrophages to stimulate different lymphocytes and induce appropriate immune responses, thus, connecting the innate to adaptive immunity, and this could also have health benefits via the consumption of SODIS treated water.
However, proteomic analysis of S. Typhimurium showed no significant differentially expressed proteins in macrophages treated with LPS, non-solar irradiated, and solar irradiated S. Typhimurium. This may be due to an overestimation of the extracted protein. However, DEPs in macrophages treated with heat-attenuated S. Typhimurium showed that macrophages may have adapted an anti-inflammatory M2 phenotype because the IFN-γ signalling pathway was downregulated. This may have contributed to non-expression of the chemokine IFN-γ in RAW264.7 cells. Moreover, proteins such as Hmox1 and Sqstm1 were upregulated, and this is also characteristic of M2 macrophages.
This study provided new insights on the effect of solar irradiated Salmonella Typhimurium and Campylobacter jejuni on the proliferation and activation of macrophages in vitro.
|
Page generated in 0.1074 seconds