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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

Determination of the quality of environmental water using GC-MS based faecal sterol analysis / Chantel Swanepoel

Swanepoel, Chantel January 2014 (has links)
Faecal indicator bacteria have traditionally been used in the detection of faecal pollution in water, but due to concerns about the lack of reliability of these indicators, alternative methods have been developed. One of which is the detection of sterols present in human and animal excreta via GC-MS analysis of water in this study. The Szűcs method was used to detect six target sterols (coprostanol, cholesterol, dehydrocholesterol, stigmasterol, β-sitosterol, and stigmastanol) in environmental water samples. An initial study was done by analysing raw sewage and effluent (human faecal sterol biomarkers) and water samples were spiked with excreta from cattle, chickens, horses, pigs, and sheep to determine faecal sterol fingerprints. The method was evaluated for quantitation and differences between the water samples from each species. Following liquid-liquid extraction, silylation and derivatization, samples were analysed by GC-MS. Standard curve assays were linear up to 160ng and the limit for quantification was 20ng. The human faecal sterol biomarker was coprostanol, while herbivore profiles were dominated by terrestrial sterol biomarkers (stigmasterol and stigmastanol). Sterol fingerprints and differences in concentrations of sterols between various animals and between animals and humans occurred, providing the opportunity to determine whether faecal pollution was from humans or from animals. The method proved sensitive enough to evaluate faecal contamination in environmental water. Groundwater was collected from bore-holes and surface water samples were collected from the Baberspan Inland Lake. Physico-chemical parameters analysed indicated that pH for surface water samples was above 6.9. The total dissolved solids (TDS) in groundwater indicated that the water was not suitable for human consumption, but could be used for livestock watering. Surface water electrical conductivity (EC) and inorganic nitrates was too high to be used for irrigational purposes. Nitrates in groundwater were too high to be consumed by humans. In groundwater, the total coliform target water quality range (TWQR) was exceeded at 53% of sites analysed and faecal coliform TWQR were exceeded at 77% sites. Surface water samples complied with TWQR with regards to faecal coliforms for full contact recreational activities and livestock watering. The TWQR for E. coli, with regards to full contact recreational activities, was within a safe range for surface water. Faecal streptococci were found in 85% of groundwater sampling sites. And surface water faecal streptococci counts exceeded the TWQR for full contact recreational activities. There is no TWQR for faecal sterols in water, but concentrations of cholesterol and coprostanol was found at three of the groundwater sites analysed. This indicates faecal contamination from possible animal and human origin. Surface water samples analysed showed that the Harts River water is clean and free of faecal sterols, while the water analysed from the inflow, hotel and outflow, cholesterol eluted, which showed faecal contamination, possibly from animals. Faecal sterol markers could be detected in groundwater and surface water, adding an extra dimension to determining the quality of water systems. An optimization and sensitivity study of the method was done on waste water treatment plant (WWTP) raw sewage and effluent. The WWTP sample analysed form Potchefstroom and Carletonville WWTP yielded all six target sterols in the raw sewage water samples, but no sterols eluted in the effluent samples. The raw sewage water sample taken from the Fochville WWTP yielded all six target sterols as well, however, the effluent yielded an unknown compound as well as cholesterol. An alternative study was done where the effluent sample volume was increased. By increasing the volume of water, one can possibly increase the amount (“load”) of sterols extracted and analysed, resulting in a higher abundance of target sterols. By using the target qualifier ions of the six target sterols, and the GC-TOF/MS software, the target sterols could still be qualitatively determined. Optimal volume for raw sewage is 300 ml water sample as this is enough to yield all 6 target sterols. For optimum water quality monitoring via faecal sterol analysis of effluent and other environmental samples, at least 1L sample volume needs to be collected and analysed. The methods described here can be applied to the analysis of environmental water samples. The technical advantages also make it suitable for routine environmental monitoring of faecal pollution. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2015
2

Determination of the quality of environmental water using GC-MS based faecal sterol analysis / Chantel Swanepoel

Swanepoel, Chantel January 2014 (has links)
Faecal indicator bacteria have traditionally been used in the detection of faecal pollution in water, but due to concerns about the lack of reliability of these indicators, alternative methods have been developed. One of which is the detection of sterols present in human and animal excreta via GC-MS analysis of water in this study. The Szűcs method was used to detect six target sterols (coprostanol, cholesterol, dehydrocholesterol, stigmasterol, β-sitosterol, and stigmastanol) in environmental water samples. An initial study was done by analysing raw sewage and effluent (human faecal sterol biomarkers) and water samples were spiked with excreta from cattle, chickens, horses, pigs, and sheep to determine faecal sterol fingerprints. The method was evaluated for quantitation and differences between the water samples from each species. Following liquid-liquid extraction, silylation and derivatization, samples were analysed by GC-MS. Standard curve assays were linear up to 160ng and the limit for quantification was 20ng. The human faecal sterol biomarker was coprostanol, while herbivore profiles were dominated by terrestrial sterol biomarkers (stigmasterol and stigmastanol). Sterol fingerprints and differences in concentrations of sterols between various animals and between animals and humans occurred, providing the opportunity to determine whether faecal pollution was from humans or from animals. The method proved sensitive enough to evaluate faecal contamination in environmental water. Groundwater was collected from bore-holes and surface water samples were collected from the Baberspan Inland Lake. Physico-chemical parameters analysed indicated that pH for surface water samples was above 6.9. The total dissolved solids (TDS) in groundwater indicated that the water was not suitable for human consumption, but could be used for livestock watering. Surface water electrical conductivity (EC) and inorganic nitrates was too high to be used for irrigational purposes. Nitrates in groundwater were too high to be consumed by humans. In groundwater, the total coliform target water quality range (TWQR) was exceeded at 53% of sites analysed and faecal coliform TWQR were exceeded at 77% sites. Surface water samples complied with TWQR with regards to faecal coliforms for full contact recreational activities and livestock watering. The TWQR for E. coli, with regards to full contact recreational activities, was within a safe range for surface water. Faecal streptococci were found in 85% of groundwater sampling sites. And surface water faecal streptococci counts exceeded the TWQR for full contact recreational activities. There is no TWQR for faecal sterols in water, but concentrations of cholesterol and coprostanol was found at three of the groundwater sites analysed. This indicates faecal contamination from possible animal and human origin. Surface water samples analysed showed that the Harts River water is clean and free of faecal sterols, while the water analysed from the inflow, hotel and outflow, cholesterol eluted, which showed faecal contamination, possibly from animals. Faecal sterol markers could be detected in groundwater and surface water, adding an extra dimension to determining the quality of water systems. An optimization and sensitivity study of the method was done on waste water treatment plant (WWTP) raw sewage and effluent. The WWTP sample analysed form Potchefstroom and Carletonville WWTP yielded all six target sterols in the raw sewage water samples, but no sterols eluted in the effluent samples. The raw sewage water sample taken from the Fochville WWTP yielded all six target sterols as well, however, the effluent yielded an unknown compound as well as cholesterol. An alternative study was done where the effluent sample volume was increased. By increasing the volume of water, one can possibly increase the amount (“load”) of sterols extracted and analysed, resulting in a higher abundance of target sterols. By using the target qualifier ions of the six target sterols, and the GC-TOF/MS software, the target sterols could still be qualitatively determined. Optimal volume for raw sewage is 300 ml water sample as this is enough to yield all 6 target sterols. For optimum water quality monitoring via faecal sterol analysis of effluent and other environmental samples, at least 1L sample volume needs to be collected and analysed. The methods described here can be applied to the analysis of environmental water samples. The technical advantages also make it suitable for routine environmental monitoring of faecal pollution. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2015
3

On-site Wastewater Treatment and Reuse Using Recirculatory Evapotranspiration Channels in Regional Queensland

Kele, Benjamin Mark, b.kele@cqu.edu.au January 2005 (has links)
The Central Queensland University developed an on-site wastewater treatment and reuse technology. Septic tanks were used for primary treatment and the discharged effluent was then pumped though a series of contained channels. The channels were designed to be a modified evapotranspiration trench; they were comprised of an aggregate layer and a soil layer in which were planted a variety of plants. The aggregate and the soil provided physical filtration, the microorganisms within the effluent, aggregate and soil provided nutrient reuse and transformation and the plants also used the nutrients and reused the treated effluent through evapotranspiration. Any effluent that was not transpired was returned to a holding tank and pumped through the evapotranspiration again. The treatment technology was assessed in relation to its ability to treat effluent in a sustainable manner. The water and soil was examined for concentrations of nutrients, heavy metals, salts, sodium, and organic carbon %. The pH, temperature and number of colony forming units of certain microorganism potential pathogens were also inspected in the soil and the water. The plants grown within the evapotranspiration channels were assessed in regards to their health, water usage, and in some cases potential pathogens on fruit. The infrastructure that was used to construct the wastewater treatment and reuse system was also evaluated in regards to reliability and maintenance. Certain limiting factors, in particular sodicity and salinity were identified, but the trial was successful and a sustainable form of on-site wastewater treatment and reuse technology was developed.
4

Avalia??o da efici?ncia de filtros anaer?bios na remo??o de coliformes fecais e ovos de helmintos

Cavalcante, Fernanda Lima 19 March 2007 (has links)
Made available in DSpace on 2014-12-17T15:03:17Z (GMT). No. of bitstreams: 1 FernandaLC.pdf: 619525 bytes, checksum: b172a729547f262e355961911646e833 (MD5) Previous issue date: 2007-03-19 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The technology of anaerobic reactors for sanitary wastewater treatment has been extensively developed in Brazil, and today it is practically consolidated. They present several advantages, such as low construction and operating costs, and low sludge production, the anaerobic reactors are an attractive alternative to minimize problematic lack of basic sanitation in urban areas, and also of the rural areas. The anaerobic filters have been widely used in Brazil. It produces an effluent with low concentration of organic matter and solids suspended, besides conserving the nutrients, therefore, it is good for use in irrigation, but the practice must be associated with knowledge of the pathogens presence. The main objective of this study was to evaluate the efficiency of anaerobic filters in removal faecal coliforms and helminth eggs, and to verify if the effluent can be used for agricultural purposes, according to the World Organization of Health (WHO, 1989). The protocol used to enumerate helminths eggs was the modified Bailenger method, (Ayres and Mara, 1996) recommended by WHO for evaluation of raw effluent and treated effluent. The membrane filtration method was utilized to determine the concentrations of faecal coliforms. Three different systems of sewer treatment composed by anaerobic filters were analyzed. The results, in a general analysis, showed that all the researched systems reached a larger removal than 93% to helminth eggs, resulting in an effluent with smaller average than 1 egg/L. One of these systems, Sistema RN, reached a larger removal than 99%, confirming the good performance of the anaerobic filters in removal helminths eggs. Even with low concentrations of eggs in the influent, the filters were capable to remove this parameter efficiently. About faecal coliforms, it was observed for all the researched systems an effluent with 106 CFU/100mL. The high concentrations to faecal coliforms in the effluent just allow reuse for restricted irrigation, in agreement with the guidelines of WHO. Although the researched systems have not removed faecal coliforms efficiently, the results indicated a good efficiency of the anaerobic filters in removal helminth eggs / A tecnologia de reatores anaer?bios para o tratamento de esgoto sanit?rio vem sendo extensivamente desenvolvida no Brasil, e hoje encontra-se praticamente consolidada. Apresentando diversas vantagens, como baixos custos de constru??o e opera??o, e baixa produ??o de lodo, os reatores anaer?bios s?o uma alternativa bastante atrativa para a mitiga??o dos problemas de saneamento b?sico urbano, e tamb?m das ?reas rurais. Os filtros anaer?bios v?m sendo bastante aplicados no Brasil. Sua utiliza??o produz um efluente com baixa concentra??o de mat?ria org?nica e s?lidos suspensos, al?m de conservar os nutrientes, sendo por isso muito bom para irriga??o com fins produtivos, desde que sejam resguardados os cuidados com a presen?a de organismos patog?nicos. Este trabalho teve por objetivo avaliar a efici?ncia de filtros anaer?bios na remo??o de coliformes fecais e ovos de helmintos, e verificar se os mesmos atendem ?s recomenda??es sanit?rias para reuso em irriga??o, segundo a Organiza??o Mundial de Sa?de - OMS (WHO, 1989). Para enumera??o dos ovos de helmintos foi utilizada a t?cnica de Bailenger modificada (Ayres e Mara, 1996), que deu origem ? metodologia atualmente recomendada pela OMS para avalia??o de ?guas residu?rias brutas e tratadas. Para determina??o de coliformes fecais foi utilizado o m?todo da membrana filtrante. Foram analisados tr?s diferentes sistemas de tratamento de esgoto compostos por filtros anaer?bios. Numa an?lise geral dos resultados, observou-se que todos os sistemas pesquisados atingiram efici?ncia maior que 93% para remo??o de ovos de helmintos, resultando em um efluente final com valor m?dio menor que 1 ovo/L. Um dos sistemas, o Sistema RN, alcan?ou uma remo??o maior que 99%, confirmando o bom desempenho dos filtros anaer?bios na remo??o de ovos de helmintos. Mesmo com baixas concentra??es de ovos no afluente, os filtros foram capazes de remover eficientemente este par?metro. Em rela??o ? contagem de coliformes fecais, foi observado, para todos os sistemas pesquisados um efluente final com cerca de 106 UFC/100mL. As altas concentra??es de coliformes fecais no efluente dos filtros permitem a reutiliza??o apenas para irriga??o restrita, de acordo com as diretrizes da OMS. Apesar dos sistemas pesquisados n?o removerem eficazmente coliformes fecais, os resultados encontrados no presente estudo indicaram uma boa efici?ncia dos filtros anaer?bios na remo??o de ovos de helmintos

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