The significant increase in the sewage sludge production in treatment plants makes anaerobic digestion more important as a stabilization process. However hydrolysis is the rate-limiting step of anaerobic digestion because of the semirigid structure of the microbial cells. Pretreatment of waste activated sludge (WAS) leads to disruption of cell walls and release of extracellular and intracellular materials. Therefore biodegradability of sludge will be improved in terms of more biogas production and sludge minimization. Among the pretreatment methods, alkaline, thermal and thermochemical pretreatments are effectual ones. Considering the effect of thermal pretreatment, microwave technology in which the sample reaches to elevated temperatures very rapidly is a very new pretreatment method. However no previous research has been conducted to test the effectiveness of microwave (MW) irradiation combined with alkaline pretreatment. Since both of these techniques seem to be highly effective, their combination can act synergistically and even more efficient method can be obtained. Therefore the main objective of this study was to investigate the effect of combination of a chemical method (alkaline pretreatment) and a physical method (microwave irradiation) in improving anaerobic digestion of WAS. In the first part of the study, alkaline and MW pretreatment methods were examined separately, then their combinations were investigated for the first time in the literature in terms of COD solubilization, turbidity and CST. Highest SCOD was achieved with the combined method of MW+pH-12. In the second part, based on the results obtained in the first part, alkaline pretreatments of pH-10 and pH-12 / MW pretreatment alone and combined pretreatments of MW+pH-10 and MW+pH-12 pretreated WAS samples were anaerobically digested in small scale batch anaerobic reactors. In correlation with the highest protein and carbohydrate releases with MW+pH-12, highest total gas and methane productions were achieved with MW+pH-12 pretreatment reactor with 16.3% and 18.9% improvements over control reactor, respectively. Finally the performance of MW+pH-12 pretreatment was examined with 2L anaerobic semi-continuous reactors. 43.5% and 53.2% improvements were obtained in daily total gas and methane productions. TS, VS and TCOD reductions were improved by 24.9%, 35.4% and 30.3%, respectively. Pretreated digested sludge had 22% improved dewaterability than non-pretreated digested sludge. Higher SCOD and NH3-N concentrations were measured in the effluent of pretreated digested sludge / however, PO4-P concentration did not vary so much. Heavy metal concentrations of all digested sludges met Soil Pollution Control Regulation Standards. Finally a simple cost calculation was done for a MW+pH-12 pretreatment of WAS for a fictitious WWTP. Results showed that, WWTP can move into profit in 5.5 years.

Ultrasonic sludge disintegration &ndash / the most commonly used mechanical pretreatment method- enables the occurrence of cavitation bubbles to extract intracellular material from the cell into aqueous phase. However, there is a lack of information on the volatile solids loading on the anaerobic digestion process performance of ultrasonically treated sludge. In this thesis work, the effect of sonication on disintegration of waste activated sludge (WAS) and an important parameter digester F/M (food to microorganism) ratio on ultrasonically treated WAS were investigated. First, preliminary studies were conducted. It was obtained that when the sonication power and time increased, soluble COD in the supernatant increased as well. Then, batch anaerobic digestion tests were conducted. Effect of F/M ratio in the digesters by using sonicated sludges at different powers was analyzed. For the sludge sonicated at high power, the methane content increased up to 55.1 % at F/M ratio of 10 compared to untreated sludge. On the other hand, methane generation rate slowed down with the increase in F/M ratio. Moreover, 10 % and 15 % increase in the destruction of MLVSS and total COD content was observed for sonicated sludges compared to the untreated sludges, respectively. In summary, both the sonication as a pretreatment method and the increase in digester F/M ratio increased the biogas production and the solids reduction during anaerobic digestion prosess. These results may have important implications for the operation of full scale systems in terms of system efficiency and operation.

Activated sludge systems are the most widely used biological wastewater treatment processes all over the world. The main working principles of an activated sludge system are the oxidation of biologically degradable wastes by microorganisms and the subsequent separation of the newly formed biomass from the treated effluent. Separation by settling is the most troublesome stage of an activated sludge process. A decrease in the efficiency of the separation of microbial biomass from the treated effluent causes a decrease in the overall efficiency of the treatment plant. The efficiency of the separation process is related to the bioflocculation, which can be briefly defined as the aggregation of the bacteria into flocs through flocculation. Bioflocculation depends on the extracellular polymers (EPS) that are produced by microorganisms. The operating conditions of the activated sludge system is a key determinant of the synthesis of EPS and bioflocculation. The main objective of this study is to find out the effect of magnesium ions on the bioflocculation process under phosphorus deficient and sufficient conditions. In order to achieve this aim, the effects of magnesium ion in 4 different concentrations (0.9, 5, 10 and 20 meq/L) are investigated in semi continuous reactors. The reactors are operated at a mean cell residence time of 8 days and 20&ordm / C temperature. When reactors are confirmed to be at steady state, several sets of analysis are conducted. In particular, the surface chemical parameters including EPS and its components, electrical charge, and hydrophobicity as well as physical properties such as settlability, filterability, viscosity, floc strength, and turbidity are examined. It has been understood that phosphorus deficiency causes severe filamentous bulking under magnesium rich conditions. Increasing the phosphorus concentration in the influent can cure this problem. After the sludges are cured some granular structures were observed in the microscopic investigations and they are thought to be polyphosphate granules in which microorganisms tend to accumulate phosphorus when they find the adequate source after a starvation period. To consider the reactors operated at phosphate present conditions, it has been found that EPS increases with increasing influent magnesium concentration. However, protein type EPS (EPSP) exhibits a sharper increase when compared to the carbohydrate type EPS (EPSC) indicating the selective attitude of magnesium ions to protein type of polymers. It has been understood that the increase in the influent magnesium concentration results in an increase in dewaterability and zone settling velocity, and a decrease in the viscosity. Hydrophobicity was found to exhibit a maximum value at 10 meq/L magnesium fed sludge and then it dropped back. Surface charge values also made a minimum at 10 meq/L reactor and then no change occurred at the increase of the magnesium concentration to 20 meq/L. Finally, COD values were found to increase with the increasing magnesium concentration due to the increasing EPS.

Made available in DSpace on 2016-12-23T14:06:52Z (GMT). No. of bitstreams: 1 Wallace de Medeiros Cazelli.pdf: 2536965 bytes, checksum: fd72ec2332e1a2fa61b0e4bccb66708e (MD5) Previous issue date: 2013-01-30 / The modern connection between the basic attention to health and sanitation had the beginning with the Declaration of Alma Ata in 1978, when the proposal to establish local health services focusing on the real needs of the population had as one of its elementary actions the drinking-water supply and sewage collection and treatment. Thirty four years later the review of the literature demonstrates that the sanitation and health had been more theorized than actually combined to promote improvement in the health conditions of populations around the world. Considering these facts, the motivation to produce this study has been found, which is: knowing and researching its interfaces, its associations and how they contribute to the health of the population in the cities of Espírito Santo. To perform the study objectives, the methodology has been used was the statistical analysis of a variable dependent on health and sanitation indicators, on secondary data, referring to the State s municipalities in 2001, 2006 and 2011. The literature review indicates that in recent years the parasitic and infectious diseases caused by the lack of sanitation are decreasing in areas where interventions in primary health care can be found, making them good indicators in planning and monitoring of health services. The results indicated a strong connection between primary health care and the provision of water supply and sewage collection by collective network, over the variable rate of diarrhea in children under two years old, in 2001, 2006 and 2011 in the municipalities in Espírito Santo. The analysis indicate that, in areas where the teams of community health agents work and the family health strategy, good results in controlling diarrhea are presented in all years of the study. And these outcomes are increased when associated to more coverage of public water supply systems and sanitation. This complement confirms the requirement for greater investments in the actions planned and performed on a intersectorial way by the municipal public administrations / A moderna relação entre a atenção básica à saúde e o saneamento básico tem sua certidão de nascimento lavrada na Declaração de Alma Ata em 1978, quando a proposta de instituir serviços locais de saúde centrados nas necessidades reais da população trazia como suas ações essenciais elementares o abastecimento de água potável e a coleta e tratamento de esgoto sanitário. Passados 34 anos a revisão da literatura nos revela que a relação entre saneamento e saúde foi mais teorizada do que de fato conjugada para promover melhorias nas condições de saúde das populações mundo a fora. Daí a motivação do presente estudo: conhecer suas interfaces, suas associações e como estas contribuem para a saúde da população nos municípios capixabas. Para cumprir os objetivos a metodologia empregada consistiu na análise estatística de uma variável dependente e de indicadores de saúde e saneamento, utilizando dados secundários de fontes oficiais dos municípios capixabas nos anos de 2001, 2006 e 2011. A revisão bibliográfica aponta que nos últimos anos as doenças infecciosas e parasitarias causadas pela falta de saneamento básico estão diminuindo nos territórios onde encontramos intervenções de Atenção Primária à Saúde, tornando-as bons indicadores no planejamento das ações de saúde. Os resultados mostraram forte relação entre a Atenção Primária à Saúde e a oferta de abastecimento de água potável e da coleta de esgoto por rede coletiva, sobre a variável taxa de diarréia em menores de 2 anos, nos anos de 2001, 2006 e 2011 nos municípios capixabas. A análise mostra que, em áreas de atuação de equipes de Agentes Comunitários de Saúde e da estratégia de Saúde da Família, bons resultados no controle de diarréias são apresentados em todos os anos do estudo, sendo potencializados quando consorciados por maiores coberturas dos sistemas públicos de abastecimento de água e esgotamento sanitário. Esta complementaridade confirma a necessidade de maiores investimentos em ações planejadas e executadas de forma intersetorial pelas gestões públicas municipais