Grande parte do lodo gerado em ETAs no Brasil ainda é disposta em rios ou em aterros sanitários. Contudo, principalmente em grandes centros urbanos, condições de licenciamento ambiental restritivas e custos logísticos crescentes tem levantado interesse em usos benéficos para esse resíduo. Um obstáculo para a mudança de paradigma recai no fato de que muito raramente operadores e projetistas de ETAs nacionais conseguirem prever, com algum grau de confiabilidade, a massa e volume de resíduos produzidos pelo tratamento da água bruta. Geralmente, usa-se para esse fim fórmulas empíricas, que relacionam a produção de lodo à concentração de sólidos em suspensão totais (SST) na água bruta e à dosagem de produtos químicos. Os objetivos deste trabalho são: comparar o desempenho de dois dos principais métodos quantitativos de estimativa de produção de lodo o método de fórmulas empíricas, e o do balanço de massa; investigar a prática disseminada de se estimar a concentração de sólidos em suspensão totais na água bruta por meio de modelos de regressão linear com a turbidez como variável independente; e delinear condições para a aplicação dessa correlação. Foram utilizados dados de seis ETAs de ciclo completo operadas pela SABESP (ABV, Alto Cotia, Cubatão, Guaraú, Franca e Presidente Prudente), além de dados de monitoramento de 130 estações de monitoramento de águas superficiais da CETESB. Os resultados sugerem que a identificação de correlações significativas entre concentração de SST e turbidez é elusiva, e não constitui tarefa trivial. Do universo de 130 estações da CETESB, somente 7 apresentaram correlação significativa; das ETAs, somente Presidente Prudente. Modelos de regressão alternativos utilizando outras variáveis (cor, vazão média mensal e mês), combinadas com a turbidez ou isoladamente, foram desenvolvidos. Somente a inclusão do mês como variável categórica foi capaz de aumentar o poder explicativo do modelo baseado exclusivamente na turbidez, sugerindo que a relação entre turbidez e concentração de SST é variável sazonalmente. Mediante a comparação com balanços de massa, foram identificados alguns fatores que afetam o poder de predição da fórmula empírica desenvolvida pela American Water Works Association, algumas vezes de maneira drástica. Em geral, conclui-se que o uso de fórmulas empíricas principalmente em conjunto com modelos de regressão entre concentração de SST e turbidez possa não ser recomendável. / Most of the water treatment plant (WTP) residuals generated in Brazil is still discharged in water bodies, or disposed of in landfills. However, especially in large urban areas, ever stringent conditions for environmental permits e rising logistical costs have put into focus beneficial uses for those residuals. A major obstacle for paradigm change in that aspect lies in the fact that very rarely water treatment plant operators and designers are able to predict with some degree of certainty the mass and volume of residuals produced by the treatment process. Usually, empirical formulas are used for that end, which relates the residuals production rate to the concentration of total suspended solids (TSS) in the raw water, and the chemicals dose. The objectives of this work are: to compare the performance of two of the main quantitative estimation methods for residuals production the empirical formulas and the mass balance; to investigate the widespread practice of estimating the concentration of TSS using turbidity as a surrogate; and to identify the conditions under which such procedure is acceptable. For that end, data from six WTPs operated by SABESP (ABV, Alto Cotia, Cubatão, Guaraú, Franca e Presidente Prudente), plus 130 surface water monitoring stations operated by CETESB, was analyzed. Alternative regression models, employing other independent variables (color, average monthly flow and month) singly or in combination with turbidity, were developed. Only the inclusion of the month as a categorical variable was capable of enhancing the explaining power of the turbidity model, suggesting that the relation between turbidity and TSS concentration is seasonally variable. The results suggest that identification of such significant correlations between TSS concentration and turbidity is elusive at best, and doesn\'t amount to a trivial task. Out of the universe of 130 monitoring stations, in only 7 a good degree of correlation was found; of the WTPs, that was the case only in Presidente Prudente. Through the comparison with the mass balances, some factors that affect the predictive power of the American Water Works Association sometimes drastically a were identified. In general, it is concluded that the use of empirical formulas especially when combined with turbidity and TSS concentration regression models may not be recommended.

Grande parte do lodo gerado em ETAs no Brasil ainda é disposta em rios ou em aterros sanitários. Contudo, principalmente em grandes centros urbanos, condições de licenciamento ambiental restritivas e custos logísticos crescentes tem levantado interesse em usos benéficos para esse resíduo. Um obstáculo para a mudança de paradigma recai no fato de que muito raramente operadores e projetistas de ETAs nacionais conseguirem prever, com algum grau de confiabilidade, a massa e volume de resíduos produzidos pelo tratamento da água bruta. Geralmente, usa-se para esse fim fórmulas empíricas, que relacionam a produção de lodo à concentração de sólidos em suspensão totais (SST) na água bruta e à dosagem de produtos químicos. Os objetivos deste trabalho são: comparar o desempenho de dois dos principais métodos quantitativos de estimativa de produção de lodo o método de fórmulas empíricas, e o do balanço de massa; investigar a prática disseminada de se estimar a concentração de sólidos em suspensão totais na água bruta por meio de modelos de regressão linear com a turbidez como variável independente; e delinear condições para a aplicação dessa correlação. Foram utilizados dados de seis ETAs de ciclo completo operadas pela SABESP (ABV, Alto Cotia, Cubatão, Guaraú, Franca e Presidente Prudente), além de dados de monitoramento de 130 estações de monitoramento de águas superficiais da CETESB. Os resultados sugerem que a identificação de correlações significativas entre concentração de SST e turbidez é elusiva, e não constitui tarefa trivial. Do universo de 130 estações da CETESB, somente 7 apresentaram correlação significativa; das ETAs, somente Presidente Prudente. Modelos de regressão alternativos utilizando outras variáveis (cor, vazão média mensal e mês), combinadas com a turbidez ou isoladamente, foram desenvolvidos. Somente a inclusão do mês como variável categórica foi capaz de aumentar o poder explicativo do modelo baseado exclusivamente na turbidez, sugerindo que a relação entre turbidez e concentração de SST é variável sazonalmente. Mediante a comparação com balanços de massa, foram identificados alguns fatores que afetam o poder de predição da fórmula empírica desenvolvida pela American Water Works Association, algumas vezes de maneira drástica. Em geral, conclui-se que o uso de fórmulas empíricas principalmente em conjunto com modelos de regressão entre concentração de SST e turbidez possa não ser recomendável. / Most of the water treatment plant (WTP) residuals generated in Brazil is still discharged in water bodies, or disposed of in landfills. However, especially in large urban areas, ever stringent conditions for environmental permits e rising logistical costs have put into focus beneficial uses for those residuals. A major obstacle for paradigm change in that aspect lies in the fact that very rarely water treatment plant operators and designers are able to predict with some degree of certainty the mass and volume of residuals produced by the treatment process. Usually, empirical formulas are used for that end, which relates the residuals production rate to the concentration of total suspended solids (TSS) in the raw water, and the chemicals dose. The objectives of this work are: to compare the performance of two of the main quantitative estimation methods for residuals production the empirical formulas and the mass balance; to investigate the widespread practice of estimating the concentration of TSS using turbidity as a surrogate; and to identify the conditions under which such procedure is acceptable. For that end, data from six WTPs operated by SABESP (ABV, Alto Cotia, Cubatão, Guaraú, Franca e Presidente Prudente), plus 130 surface water monitoring stations operated by CETESB, was analyzed. Alternative regression models, employing other independent variables (color, average monthly flow and month) singly or in combination with turbidity, were developed. Only the inclusion of the month as a categorical variable was capable of enhancing the explaining power of the turbidity model, suggesting that the relation between turbidity and TSS concentration is seasonally variable. The results suggest that identification of such significant correlations between TSS concentration and turbidity is elusive at best, and doesn\'t amount to a trivial task. Out of the universe of 130 monitoring stations, in only 7 a good degree of correlation was found; of the WTPs, that was the case only in Presidente Prudente. Through the comparison with the mass balances, some factors that affect the predictive power of the American Water Works Association sometimes drastically a were identified. In general, it is concluded that the use of empirical formulas especially when combined with turbidity and TSS concentration regression models may not be recommended.

The thesis proposes the low-cost solution of Differential GPS using Arduino as a Master Control Unit. The thesis provides the methods of GPS position augmentation, which is available for varied applications such as drones or autonomous lawnmowers operated in a private sector. Used methods of GPS positioning accuracy improvements are based on a Satellite-Based Augmentation System (SBAS) and pseudorange residuals.

Esta tesis consiste en la aplicación de la electroforesis capilar (CE) a la separación y cuantificación de especies cianuradas y al estudio del comportamiento de estas especies y de su destino final. Como material de estudio se han seleccionado distintos procesos industriales (lixiviación de minerales y arenas auriferas, disoluciones de proceso en industrias de recubrimientos electrolíticos, lixiviación intensiva en autoclave de convertidores de automóvil) donde los cianuros tienen aplicación. En la primera parte de la tesis se ha realizado un estudio detallado de las características de la técnica CE, y posteriormente se ha optimizado una metodología para aplicarla a los distintos problemas que se recogen en el resto de la memoria. La segunda parte de la tesis se ha dedicado a la aplicación de la ce al estudio de la lixiviación con NaCN de los metales preciosos y estratégicos presentes en minerales auriferos (Au, Ag) y en convertidores de automóviles (PT, PD, RH), obteniendo finalmente un método analítico capaz de ser utilizado para el seguimiento de este tipo de procesos. En la tercera parte de la tesis se ha realizado la determinación del cianuro libre, del débilmente ligado y del total en aguas procedentes de la industria de los recubrimientos electrolíticos y en disoluciones de cianuros oxidadas con hipoclorito, que es el método mas extendido para tratar las aguas industriales. Para analizar estas formas de cianuros, se han planteado dos soluciones, basadas en la detección indirecta y en la derivatización.La problemática de la detección del cianuro libre (CN- y HCN (aq)) y de especies relacionadas (CNO-, SCN-, NO3, CI-, SO42- y CIO-) resuelto con la utilización de la fluorescencia indirecta con un detector prototipo con fuente láser.La determinación de cianuros en muestras reales de disoluciones de recubrimientos electrolíticos se ha conseguido mediante su derivatizacion a NI(CN)42- utilizando una disolución de NI(II)-NH3.

Thesis (Ph. D.)--University of Missouri-Columbia, 2001. / Typescript. Vita. Includes bibliographical references (leaves 373-387). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2001. / Typescript. Vita. Includes bibliographical references (leaves 373-387). Also available on the Internet.

The environmental and agricultural viability of land disposal of a water treatment residue (WTR) from the Midmar Water Treatment Works of Umgeni Water was investigated by determining answers to four broad questions: 1. What effects would the application of the WTR have on plants growing on the treated soils? 2. What effects would application of the WTR have on soil chemical properties? 3. What effects would the WTR have on the soil solution composition (and by implication the quality of the groundwater)? 4. Could this material be used to reduce solubility of potential pollutants? To answer these questions, the following experiments were set up, and their respective results are reported. 1. Effects of the water treatment residue on plant growth This was investigated in a pot experiment and two field experiments. In the pot experiment five soils, two Huttons (Hu-M and Hu-T), an Inanda (la-C), a Namib (Nb-F) and a Shortlands (Sd) were used to grow perennial ryegrass ((Lolium perellne). All samples were fertilized with a basal dressing of N, P, K, Mg and S. Two lime levels were added to the Ia-C and Nb-F soils, the higher calculated to reduce acid saturation to 1%, and the lower being half of that. The WTR was applied at rates of 0, 40, 80 and 120 Mg ha-1. All treatments were in triplicate. Eight cuts in all were made of the perennial ryegrass. The dry matter (DM) yield of perennial ryegrass grown in the pot experiment increased with the WTR applied in all five soils although the highest increase was with the acidic Ia-C and Nb-F soils. The fact that the highest yields were on the strongly acid soils suggests that the liming effect of the WTR could have contributed, more so considering that lime also increased yields in these soils. It was, however, clear that no one factor was responsible for the increase in yield as the timing effect could not explain the results of the other three soils. At the two field experiments perennial ryegrass was grown at Brookdale Farm from 1998 to 2001, after which the site was re-seeded with tall fescue (Festuca arundinaceae). At Ukulinga Farm tall fescue was grown from the outset in 2000. In the two field experiments with both perennial ryegrass and tall fescue, no significant increase in yield was apparent. Importantly, however, from an environmental point of view there was no decrease in yield whether the WTR was incorporated or applied as a mulch. This was observed even at the highest rates of application, namely 1280 Mg ha-1. The growth on the mulched plots was often observed to be better than any of the other treatments, including the control. Analysis of the plant material from both pot and field experiments indicated that the WTR neither pollution of the groundwater by nitrates. However, analysis of saturated pastes from soils at both field experiments showed that the levels of nitrate were increased by application of the WTR in only the fallow plots. 4. The water treatment residue as a possible pollutant-reducing agent The effect of the water treatment residue on the sorption of P and heavy metals (Cd, Ni and Zn) was studied in the laboratory. Soils treated with WTR were equilibrated for 6 hours in 0.005 M calcium cWoride solution containing a known concentration of each element. For the coarse-textured soils, initial P concentrations ranged from 0 to 1000 mg kg-1 as opposed to 0 to 1800 mg kg-1 for the clay soils. Treatments of WTR used were 0, 80, 320 and 1280 Mg ha-1, both incubated and non-incubated. At high initial P solution concentrations, the WTR increased the extent of sorption in the coarser textured soils (Hu-T, Nb-A, Nb-F, Va and We), and decreased it in highly sorbing Av, Hu-M, la-C and la-W soils. In general though, the WTR greatly reduced soluble P. For Cd, Ni and Zn only one concentration, 50 mg kg-1, was studied using the incubated soil samples as affected by WTR rates from 0 to 1280 Mg ha-1. For all three metals, the amount sorbed increased with increase in amount of WTR for the nine soils studied, namely the Av, Hu-F, Hu-M, Hu-T, la-C, la-W, Nb-F, Va and We. In many cases the sorption was so high that more than 40 mg kg-1 of the initial concentration was removed from solution. Even for those soils with high sorption capacity e.g. the Va and We, the WTR still increased sorption by up to an average of more than 25% for Cd and more than 40% for Ni and Zn. Because for the Av and la-W soils liming also increased sorption, it could be assumed that the accompanying increase in pH as a result of the addition of WTR promoted precipitation of metals, and/or the resultant increase in negative charge increased their adsorption. These results show that where excess concentrations of soluble heavy metals may occur (especially in coarse-textured soils), and where there is concern about run-off with high P concentrations then this WTR could be considered to immobilize these elements and render them less harmful to the environment. General comments and management guidelines. Based on the results reported above, it is apparent that the WTR can be safely disposed of onto land. It has been demonstrated in the current investigation that rates of application can be as high as 1280 Mg ha-1. Rates of application to land higher than 1280 Mp; ha-1 could probably be acceptable - this was the highest rate tested in this investigation - where the residue is produced in large amounts at the plant, and land for disposal is somewhat limited. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.

Las cepas de Escherichia coli productoras de toxina Shiga han emergido recientemente como patógenos humanos, provocando graves enfermedades como la colitis hemorrágica y el síndrome urémico hemolítico. Los principales factores de virulencia de estas cepas lo constituyen unas potentes citotoxinas conocidas como toxinas Shiga (codificadas por genes stx en el genoma de bacteriófagos atemperados), una proteína de membrana externa (intimina), responsable de la adhesión de la bacteria al epitelio intestinal y una enterohemolisina. La transmisión horizontal de los genes stx mediada por bacteriófagos, podría explicar la elevada diversidad de serotipos de E. coli portadores de estos genes.El objetivo de la tesis doctoral fue el análisis de la prevalencia del gen stx2 en ambientes acuáticos y la detección, el aislamiento y la caracterización de las bacterias portadoras del gen, así como el estudio de los bacteriófagos portadores del gen stx2 integrados en estas bacterias. Se diseñó un método basado en la combinación del NMP y la PCR anidada utilizando cebadores específicos para la subunidad A del gen stx2 para el estudio de prevalencia. Se analizaron aguas residuales crudas municipales y de mataderos. El gen stx2 fue detectado en todas las muestras, observándose una relación constante entre el número estimado de cepas stx2 estimado independientemente del origen de la muestra. Se caracterizaron 144 cepas portadoras del gen stx2 aisladas mediante el método de la hibridación colonial utilizando agar chromocult y una sonda específica para el gen stx2. Asímismo, se aislaron 72 cepas de E. coli O157 utilizando la técnica de la separación inmunomagnética, la siembra en el medio selectivo CT-SMAC y la detección inmunológica del antígeno O157. También se analizó el patrón de digestión del lipopolisacárido. Se seleccionaron un total de 65 cepas portadoras del gen stx2 y 28 cepas O157, como representantes. Todas las cepas fueron clasificadas como E. coli mediante la galería API 20E o secuenciación del 16S rDNA. Estas cepas fueron serotipadas detectándose 36 serotipos, algunos de los cuales no habían sido identificados previamente como portadores del gen stx2 . Posteriormente, se analizó la resistencia a diferentes antibióticos siendo las sulfonamidas, tetraciclina, cloramfenicol, trimetroprim y estreptomicina los antibióticos que presentaron mayor número de resistencias. Todas las cepas eran portadoras de una o dos de las variantes del gen stx2 descritas (c, d, e y g). Respecto a otros factores de virulencia se detectó el gen stx1 n el 28% y 20% de las cepas aisladas de agua residual urbana y agua residual de matadero bovino respectivamente. El gen eae fue detectado en las cepas E. coli O157:H7 mientras que el gen codificante para la enterohemolisina fue detectado en el 7%, 46% y el 11% de agua residual urbana, matadero bovino, y agua residual de origen mixto, respectivamente. El gen saa fue detectado en 5 cepas. Se detectó la producción de proteína Stx2 en algunas de las cepas aisladas, mayoritariamente aquellas de origen bovino. En el caso de la Stx1 un mayor porcentaje de cepas que expresaban el gen. La mayoría de las cepas aisladas presentaron bacteriófagos inducibles algunos de los cuales eran portadores del gen stx2 (mayoritariamente cepas aisladas de agua residual de matadero bovino). Los bacteriófagos portadores de distintas variantes del gen stx2 presentaron variabilidad en cuanto a su capacidad de infectar a diferentes cepas huésped. Además presentaron variabilidad en los patrones RFLP y sitio de integración. Estos bacteriófagos presentaron dos morfologías diferentes: cápsides icosaédricas hexagonales con colas cortas y cápsides alargadas con colas largas. La diversidad de bacteriófagos portadores del gen stx2 observada podría contribuir a la dispersión del gen stx2 entre las diferentes poblaciones bacterianas.ENGLISH / Shiga toxin producing Escherichia coli have emerged recently as human pathogens. The main virulence factors are the Shiga toxins (which are bacteriophage encoded), the external membrane protein called intimin, which is responsible for the adhesion of the bacterium to the intestinal epithelium and the hemorrhagic hemolysin.The aim of the study was to analyse the prevalence of the stx2 gene, the detection, isolation and characterization of the stx2 gene-carrying bacteria from aquatic environments and the characterization of the stx2 bacteriophages which are integrated in the genome of these bacteria. A combination of the NMP and the nested PCR method was used to evaluate the prevalence of the stx2 gene in raw municipal sewage and animal wastewater. The stx2 gene was detected in all the samples with a constant ratio between stx2 and the bacterial indicators analysed. 144 strains were isolated by colony blot hybridisation. 72 E. Coli O157 strains were isolated using IMS, CT-SMAC and the immunological detection of the O157 antigen. These strains were biochemically characterized and a total of 65 stx2 and 28 O157 strains were chosen as representatives for further studies.All the strains were identified as E. Colibelonging to 36 diferent serotypes. These strains antibiotics were mostly resitant to sulfonamides, tetracycline, cloramfenicol, thrimethroprim. All the strains carried one or two stx2 gene variants. The stx1 gene was detetcted in 28% and 20% of the isolated strains of urban sewage and bovine slaughterhouse. The eae gene was detected in E. ColiO157:H7, and the ehxA gene in 7%, 46% and 11% of municipal sewage, bovine slaughterhouse, and mixed slaughterhouse wastewater origin, respectively. The saa gene was detected in 5 strains. Production of Stx2 protein was detected mainly in strains from bovine origin. A greater percentage of strains expressed the stx1 gene. Most of the isolated strains harbored stx2 bacteriophages in their genome (mainly strains from bovine slaughterhouse origin), which carried different stx2 variants, presented variability in the RFLP analysis as well as in the infection to different hosts. The diversity of stx2 bacteriophages observed could contribute to the dispersion of the gene stx2 between the different bacterial populations.

Thesis (Ph. D.)--University of Missouri-Columbia, 2007. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on March 6, 2008) Includes bibliographical references.

Thesis (Ph. D.)--University of Missouri-Columbia, 2002. / Typescript. Vita. Includes bibliographical references (leaves 75-77). Also available on the Internet.