Water Treatment Plants (WTPs) supply potable water which is transferred by pumps to various end users. WTPs and other sub-systems are energy intensive with pump installed capacities varying between 75 kW – 6 000 kW. It has therefore become important to optimise the utilisation of WTPs. Cost savings can be achieved and the load on the national grid can be reduced. The aim of this study is to develop and implement load management strategies on a municipal WTP. In this investigation the high lift pumps are deemed to be the largest consumers of electricity. Strategies to safely implement load management on a WTP were researched. By optimising the operations of the pumps, significant cost savings can be achieved. Comparisons between different electricity tariff structures were done. It was found plausible to save R 990 000 annually, on a pumping station with four 1 000 kW pumps installed, when switching to a time-of-use dependent tariff structure. Strategies to optimise plant utilisation while attempting a load management study include the optimisation of filter washing methods and raw water operations. An increase of 34% in efficiency for a filter backwash cycle was achieved. To accommodate the effects of the load management on the WTP, the operation of valves that allow water to distribute within the plant was also optimised. The implemented control strategies aimed to accomplish the full utilisation of the WTP and sub-systems to achieve savings. An average evening peak period load shift impact of 2.21 MW was achieved. Due to filter modifications the plant is able to supply 5% more water daily. A conclusion is drawn regarding the success of the strategies implemented. Recommendations are made for further research. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2015

Water Treatment Plants (WTPs) supply potable water which is transferred by pumps to various end users. WTPs and other sub-systems are energy intensive with pump installed capacities varying between 75 kW – 6 000 kW. It has therefore become important to optimise the utilisation of WTPs. Cost savings can be achieved and the load on the national grid can be reduced. The aim of this study is to develop and implement load management strategies on a municipal WTP. In this investigation the high lift pumps are deemed to be the largest consumers of electricity. Strategies to safely implement load management on a WTP were researched. By optimising the operations of the pumps, significant cost savings can be achieved. Comparisons between different electricity tariff structures were done. It was found plausible to save R 990 000 annually, on a pumping station with four 1 000 kW pumps installed, when switching to a time-of-use dependent tariff structure. Strategies to optimise plant utilisation while attempting a load management study include the optimisation of filter washing methods and raw water operations. An increase of 34% in efficiency for a filter backwash cycle was achieved. To accommodate the effects of the load management on the WTP, the operation of valves that allow water to distribute within the plant was also optimised. The implemented control strategies aimed to accomplish the full utilisation of the WTP and sub-systems to achieve savings. An average evening peak period load shift impact of 2.21 MW was achieved. Due to filter modifications the plant is able to supply 5% more water daily. A conclusion is drawn regarding the success of the strategies implemented. Recommendations are made for further research. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2015

Thesis (PhD)--University of Stellenbosch, 2001. / ENGLISH ABSTRACT: Lignocellulose is the principal form of biomass in the biosphere and therefore the predominant renewable source in the environment. However, owing to the chemical and structural complexity of lignocellulose substrates, the effective and sustainable utilization of lignocellulose wastes is limited. Many environments where lignocellulose residues are ordinarily stored can be highly acidic (e.g. landfills), and under these circumstances biodegradation of the lignocellulose is slow and unhygienic. Owing to the metabolic activities of the micro-organisms, the initially acidified habitats rapidly undergoes self-neutralization. A number of pathogenic bacteria (coliforms and Salmonella sp.) are present during this slow degradation process and it is therefore imperative to improve the efficiency and hygienic effects of the biodegradation of the lignocellulose. Although the fundamentals of biodegradation of lignocellulose have been widely investigated, many issues still need to be resolved in order to develop commercially viable technology for the exploitation of these waste products. For example, owing to the complex, heterogeneous structure of lignocellulose, the degree of solubilization, modification and conversion of the different components are not clear. Likewise, the overall anaerobic degradation of lignocellulose is not understood well as yet. In this study, the emphasis was on the promotion of solid anaerobic digestion of lignocellulose wastes for environmental beneficiation and waste reutilization. The degradation of lignocellulose in landfill environments was first simulated experimentally. Once the microbial populations and the degradation products of the system were characterized, the promotion of anaerobic digestion by use of activated sludge was studied. This included acidogenic fermentation, as well as recovery of the methanogenic phase. Moreover, special attention was given to the further disposal of humic acids or humic acid bearing leachates formed in the digestive system, since these acids pose a major problem in the digestion of the lingocellulose. With ultrasonication, approximately 50% of the lower molecular weight fraction of humic acids could be decomposed into volatile forms, but the higher molecular weight fraction tended to aggregate into a colloidal form, which could only be removed from the system by making use of ultrasonically assisted adsorption on preformed aluminium hydroxide floes. This was followed by an investigation of the microbial degradation of humic acids and the toxicity of these acids to anaerobic consortia. Further experimental work was conducted to optimize the biological and abiological treatment of lignocellulose in an upflow anaerobic sludge blanket (DASB) reactor fed with glucose substrate. The humic acids could be partially hydrolysed and decomposed by the acid fermentative consortia of the granules in the DASB reactor. Finally, solid mesothermophilic lignocellulose anaerobic digestive sludge can be viewed as a humus-rich hygienic product that can improve the fertility and water-holding capacity of agricultural soil, nourish plants and immobilize heavy metals in the environment as a bioabsorbent. / AFRIKAANSE OPSOMMING: Lignosellulose is die hoofbron van biomassa in die biosfeer en is daarom ook die belangrikste hernubare bron in die omgewing. As gevolg van die chemiese en strukturele kompleksiteit van lignosellulose substrate, is die doeltreffende en volhoubare benutting van lignosellulose afval egter beperk. Die suurgehalte van die omgewings waar lignosellulose reste gewoonlik gestoor word, soos opvullingsterreine, kan hoog wees en onder hierdie omstandighede is die biodegradasie van die lignosellulose stadig en onhigiënies. As gevolg van die metaboliese aktiwiteite van die mikro-organismes ondergaan die aanvanklik aangesuurde habitatte vinnig self-neutralisasie. 'n Aantal patogeniese bakterieë (koliforme en Salmonella sp.) is deurgaans gedurende dié stadige natuurlike proses teenwoordig en dit is dus van die grootste belang om die effektiwiteit en die higiëne van die bioafbreking van die lignosellulose-substraat te verhoog. Alhoewel die grondbeginsels van die bioafbreking van lignosellulose reeds wyd ondersoek is, moet verskeie probleme nog opgelos word ten einde kommersieel haalbare tegnologie te ontwikkel vir die ontginning van afvalprodukte. Byvoorbeeld, as gevolg van die komplekse, heterogene struktuur van lignosellulose, is die graad van solubilisering en die modifikasie en omskakeling van verskillende komponente nog onduidelik. Net so word die algehele anaerobiese afbreking van lignosellulose ook nog nie ten volle verstaan nie. In hierdie ondersoek het die klem geval op die bevordering van soliede anaerobiese digestie van lignosellulose afval vir omgewingsverbetering en die benutting van die afval. Die afbreking van lignosellulose in opvullingsterreine is eers eksperimenteel gesimuleer. Nadat die mikrobiese populasies en die afbrekingsprodukte gekarakteriseer is, is die bevordering van anaerobiese digestie deur die gebruik van geaktiveerde slyk bestudeer. Dit het asidogeniese fermentasie ingesluit, sowel as herwinning van die metanogeniese fase. Spesiale aandag is gegee aan die verdere verwerking van humus sure en humussuurbevattende legate wat in die digestiewe stelsel gegenereer is, aangesien die sure probleme veroorsaak het met die vertering van die lignosellulose. Met ultrasoniese straling is nagenoeg 50% van die lae-molekulêre massafraksie van die humussure ontbind in vlugtige vorm, maar die hoë-molekulêre massafraksie het geneig om in 'n kolloïdale vorm te aggregeer, wat slegs uit die stelsel verwyder kon word deur middel van ultrasonies ondersteunde adsorpsie op voorafgevormde aluminiumhidroksiedvlokkies. Dit is gevolg deur 'n ondersoek na die mikrobiese afbreking van humus sure en die toksisiteit van die sure ten opsigte van anaerobiese konsortia. Verdere eksperimentele werk is gedoen ten opsigte van die biologiese en abiologiese behandeling van lignosellulose in 'n opwaartsvloeiende anaerobiese slikkombersreaktor (OASK) gevoer met glukosesubstrate. Die humus sure kon gedeeltelik gehidroliseer en ontbind word deur die suurgistende konsortia van die granules in die OASK reactor. Ten slotte kan die vaste termofiliese-mesofiliese anaerobiese lignosellulose verteringslik ook gesien word as 'n humusryke higiëniese produk wat die vrugbaarheid en die waterhoudende vermoë van landbougrond kan verhoog, plante kan voed en kan funksioneer as bioabsorbeerder van swaarmetale in die omgewing.

Watercourses influenced by anthropogenic activity increases in recent years and streams lose their natural character. This situation is critical particularly in small streams with minimal flow rates. The present work deals with the assessment of streams affected by discharges of treated wastewater from small waste water treatment plants. The results showed that in case of average flow in the recipient none of the monitored waste water treatment plants do not negatively affect the stream. Problems can occur when snow melts, when the lower temperature of the flowing water in the wastewater treatment plants negatively affect biological cleaning processes.

O presente trabalho foi realizado em duas fases. Na primeira, foram estimados os efeitos produzidos nos decantadores primários de uma ETE, após receber resíduo da ETA-SC, que utiliza sulfato de alumínio como coagulante. Foram realizados ensaios em colunas de sedimentação, onde os parâmetros SST, SSV, cor, turbidez, DQO, coliformes totais, Escherichia coli e parasitas, pesquisados no sobrenadante, diminuíram com o aumento da quantidade de resíduo adicionado. Com relação aos sedimentos obtidos nas colunas de sedimentação, foi encontrada maior quantidade de ST e menor resistência específica nos lodos provenientes das colunas que receberam os resíduos da ETA-SC. No teste de atividade metanogênica, a concentração molar de metano foi reduzida nos sistemas que receberam resíduo da ETA-SC, influenciando negativamente no desenvolvimento dos microrganismos metanogênicas. As espécies de microrganismos do gênero Methanothrix sp foram inibidas, sendo encontradas em maior número no frasco-reator controle e em menor quantidade a medida que se aumentou a quantidade do resíduo adicionado. Nesta etapa foi constatado que o resíduo da ETA-SC poderá apresentar interferências negativas sobre a digestão anaeróbia do lodo produzido em decantadores primários de uma ETE. Na segunda fase, na estação piloto, composta de lagoa de aeração seguida de lagoa de sedimentação, que recebeu resíduo da ETA-Fonte, que utiliza cloreto férrico como coagulante, foi verificado que tal resíduo melhorou a qualidade do efluente em termos de DQO, DBO, SST, turbidez, cor, amônio, nitrato, NTK e fosfato total. Os parâmetros ST, SDT, cloreto, nitrito, condutividade e pH não apresentaram diferenças significativas. Em relação ao exame microscópico não houve influências negativas no licor misto das lagoas de aeração. O lodo formado nas lagoas de sedimentação piloto apresentou-se em maior quantidade na lagoa que recebeu resíduo da ETA-Fonte. Neste lodo a resistência específica a filtração foi menor em comparação ao lodo da lagoa que não recebeu resíduo da ETA-Fonte. A desidratação deste lodo por centrifugação necessitou menor quantidade de polieletrólito. Baseado neste estudo não foi verificado interferências que possa impedir o lançamento do resíduo da ETA-Fonte na ETE-Araraquara. / This work was carried out in two phases. Effects of disposing the residues from a water treatment plant - ETASC, which uses alum as primary coagulant on the primary settling tanks was evaluated in the first one. Sedimentation tests using column indicated that parameters such as TSS, VSS, colour, turbidity, COD, total coliformes totais, Escherichia coli e parasites in the supernatant decreased with the increase of the amount of the water treatment wastes added to the column. With relation to the sediments produced in the column, it was found great amount of TS and lower specific solids resistance in those generated in the columns where the water treatment plant residues-WTPR were used. Molar concentration of methane was reduced in the tests performed with the sediments produced with water treatment plant residues and thus, altering negatively the development of methanogenic organisms. The growth of species of microorganism of genera Methanothrix sp was inhibited, which were found in great number in the control flask (with out WTPR) and in lower number as it was increased the amount of WTPR added to the column. It was observed that the WTPR generated in the city water treatment plant may interfere in the anaerobic digestion of sludge produced in primary settling tanks of a wastetreatment plant. A continuous pilot plant was operated in the second phase, which consisted of two aerated lagoon each one followed by a settling lagoon. Waste and WTPR from a watter treatment plant which ferric chloride were fed in one of the systems. It was observed that the use of WTPR improved the effluent quality of the settling lagoon evaluated in terms of COD, BOD, TSS, turbidity, color, ammonium, nitrate, TKN and total phosphate. Some parameters, such as TS, TDS, chloride, nitride, conductivity and pH did not present significant differences in both systems. Microscopic examinations indicated that no influence resulted in the aerated lagoon mixed liquor. A higher amount of sludge was formed in the lagoon system which received the WTPR. The specific resistance to filtration of this sludge was lower than that formed in the lagoon system with out WTPR addition. When dewatering both sludges, that one produced with the addition of WTPR required less amount of polymer. It was concluded that the WTPR produced in the water treatment plant of Araraquara may be disposed in the city wastewater treatment plant.

Lodos de duas Estações de Tratamento de Água (ETA) que utilizam cloreto férrico (ETA-Paiol-ETA-1) e sulfato de alumínio (ETA-SAAE-ETA-2) como coagulantes, foram caracterizados físico-quimicamente em duas estações do ano (chuvosa e seca) e submetidos a testes de toxicidade aguda com microcrustáceos (Daphnia similis), quironomídeos (Chironomus xanthus) e peixes (Hyphessobrycon eques) e de toxicidade crônica com microcrustáceos (D. similis). Observou-se ainda os efeitos destes lodos na comunidade bentônica dos corpos d\'água que recebem os lançamentos das ETAs. Os efeitos dos lodos nos testes de toxicidade aguda foram observados em relação a mortalidade, e, quanto aos testes de toxicidade crônica, observou-se os efeitos na reprodução (número de neonatas) e na mortalidade. Em geral, os lodos das duas ETAs não causaram toxicidade aguda aos organismos-teste, ocorrendo apenas indícios de toxicidade. O lodo da ETA que utilizava cloreto férrico causou toxicidade crônica, que foi observada na reprodução (baixo número de neonatas) e na alta taxa de mortalidade, enquanto que o lodo da ETA que utilizava sulfato de alumínio causou toxicidade crônica evidenciada apenas em relação a reprodução. Os lodos causaram efeitos adversos à fauna bentônica, evidenciados pela predominância de Diptera nos pontos de lançamento das ETAs nos corpos receptores. Constatou-se ainda a variação temporal na caracterização dos lodos em relação aos parâmetros: pH, turbidez, série de sólidos, nutrientes (N e P) e metais (AI, Mn e Fe), sendo que estes, juntamente com a DQO, foram identificados como os principais parâmetros que aumentam a degradação dos corpos receptores que recebem os lançamentos dos efluentes das ETAs. Portanto, a disposição \"in natura\" dos efluentes das ETAs prejudica à biota aquática e compromete a qualidade da água e do sedimento dos corpos receptores. / Sludges from two water treatment plants, which use ferric chloride (ETA-Paiol-ETA-1) and alum (ETA-SAAE-ETA-2) as coagulants were characterized physicall y and chemically at two seasons (wet and dry). The sludge was subjected to acute toxicity tests to cladoceran (Daphnis similis), midges (Chironomus xanthus) and fishes (Hyphessobrycon eques) and chronic toxicity tests using clacloceran (D. similis). It also was observed the impact of discharged sludge on benthic communities in surface waters at two water treatment plants. Acute toxicity tests evaluated sludge effects on mortality, while chronic toxicity tests assessed effects on reproduction and mortality. In general, sludges from two water treatment plants did not show acute toxicity on organisms-test, only toxicity traces. Ferric chloride sludge showed chronic toxicity on lower brood production and high mortality rate. Alum sludge showed chronic toxicity only on brood production. Sludges from water treatment plants caused detrimental effects to benthic macroinvertebrate communities. This effect was determined by Diptera predominance at bodies receiving discharge from water treatment plants. The turbidity, solids series, nutrients (N and P) and metals (Al, Mn and Fe) in the sludge vary when experiments are carried out in the dry and wet season. Together with COD, there were the main parameters that cause the increase in degradation of bodies receiving discharge from water treatment plants. Thus the disposal of \"in natura\" effluents from water treatment plants damages aquatic biota and affects receiving bodies water and sediment quality.

As estações de tratamento de água de abastecimento (ETAs) têm a finalidade de fornecer água potável. Neste processo de tratamento de água são gerados resíduos, os quais historicamente têm sido lançados em cursos de água, aumentando o nível de degradação destes. O presente trabalho teve por objetivo avaliar o impacto do lançamento desses resíduos numa estação de tratamento de esgoto (ETE) com reator anaeróbio de fluxo ascendente e manto de lodo (UASB), buscando estudar uma alternativa para a disposição adequada desses resíduos. Para o estudo da influência do lançamento do lodo da ETA em um reator de fluxo ascendente e manto de lodo (UASB) foram utilizados dois reatores em escala piloto. O esgoto utilizado para alimentar o sistema de tratamento foi proveniente do Conjunto Residencial da Universidade de São Paulo, já o lodo utilizado foi obtido na ETA da cidade de Juquitiba. A presente pesquisa foi dividida em três fases: a primeira etapa (Fase 1) constituiu-se na partida dos reatores UASB 1 e UASB 2; na segunda etapa (Fase 2) estudou-se o desempenho dos sistemas sob regime estabilizado; e na terceira e última etapa (Fase 3) o reator UASB 2 recebeu adição de duas dosagens de lodo de ETA, sendo a primeira de 50 mg/L (Fase 3a) e a segunda de 75 mg/L (Fase 3b), em termos de sólidos em suspensão totais. As condições operacionais adotadas foram: vazão de 50 L/h e tempo de detenção hidráulico (TDH) de 8 horas. Os resultados apresentados no texto indicaram que, com o acréscimo de lodo da ETA, o reator UASB 2 não teve seu desempenho afetado negativamente, e a remoção de matéria orgânica em termos de DQO, DBO e fósforo foi muito próxima entre os reatores UASB 1 e UASB 2. Conclui-se que com a disposição de lodo em um reator UASB, não haverá interferência prejudicial no desempenho operacional do mesmo. / Water treatment stations have the purpose of providing potable water. In this process of water treatment, a variety of residuals are produced; these, historically have been discharged into water streams, increasing the water pollution. The objective of this work was to evaluate the impact of discharging residuals in a treatment station with an Upflow Anaerobic Sludge Blank Reactor (UASB), and try to find an alternative for the appropriate treatment of these. For the study of the influence of discharging WTA sludge into a UASB reactor, two reactors in pilot scale were used. The disposals used to feed the treatment system came from the apartment building where Sao Paulo University students live, while the sludge used was obtained in the water treatment station from Juquitiba city. This research has been divided into three stages: The first one (Stage 1) consisted of the setting of the reactors UASB1 and UASB2. In the second stage (Stage 2) it was studied the performance of the systems in the balance regime. In the third one (Stage 3), the reactor UASB2 received the supply of two portions of WTA sludge, the first one of 50 mg/L (Stage 3a) and the second one of 75 mg/L (Stage 3b). These amounts are determined in terms of the TSS. The operational conditions adopted were flow of 50 L/h and TDH of eight hours. The results obtained indicated that with the addition of WTA sludge the reactor UASB2 did not show inferior performance. At the same time the organic material removal, in terms of DQO, DBO and phosphorous content, was similar between the reactors UASB1 and UASB2, concluding that with the supply of WTP sludge in the reactor UASB, there won\'t he detrimental effects in the reactor performance.

O presente trabalho foi elaborado com o intuito de equacionar dois problemas: redução do impacto ambiental do lançamento do lodo da ETA Mirassol in naturanos córregos e a redução de custos através da redução na quantidade de lodo enviada para o aterro sanitário e da redução no volume do agregado miúdo o qual, apesar de não representar o maior custo entre os materiais necessários para a confecção do concreto, representa uma redução de custos para a empresa concessionária que precisa recompor diariamente as calçadas que são quebradas para a execução de seus serviços de manutenção nos sistemas de água e esgoto. Devido ao fato de a ETA Mirassol ainda não dispor de um plano de gerenciamento dos resíduos de seu tratamento, como metodologia de secagem das amostras de lodo, optou-se pela simulação de lagoa de lodo fora de escala em que o lodo ficou exposto ao sol durante períodos diferentes de 15 e 30 dias. A primeira amostra, mais seca, foi utilizada nos ensaios de lixiviação e solubilização e a segunda nos ensaios envolvendo o concreto. Foram realizados ensaios de lixiviação e solubilização com o objetivo de classificar o lodo de acordo com a ABNT NBR 10.004/2004 os quais, resultaram em excesso nos teores de cádmio, chumbo e, principalmente, de manganês, cerca de 400 vezes maior que o permitido. Por conta disto, o lodo pôde ser classificado como um resíduo classe II A, ou seja, não perigoso e não inerte. Vale destacar que apesar de coagulado com policloreto de alumínio, o lodo não apresentou teores deste metal que superassem os limites da norma. Voltando a atenção para o concreto de calçada, verificou-se que não existem normas ou padrões que determinem a maneira adequada de executá-Io. Desta forma, optou-se por simular a confecção do concreto realizada no dia-a-dia pelos pedreiros, compreendendo o traço 1:2:3 (cimento:areia:brita) em massa e com o acompanhamento visual da sua trabalhabilidade. A análise de viabilidade da utilização do lodo como agregado foi realizada com base nos ensaios de compressão axial e compressão diametral, também conhecido como ensaio brasileiro (tração). Estes ensaios demonstraram que para os traços que utilizam 5%, 10% e 20% de lodo, foram obtidas resistências à compressão axial superiores à meta de 15 MPa o que foi considerado bastante satisfatório uma vez que são recomendados para calçadas valores de 10 MPa. Já para os ensaios de tração, não há referências, mas pôde-se constatar que a utilização do lodo como composto com areia como agregado miúdo interfere sensivelmente nos resultados, sendo recomendada a utilização de porcentagens próximas a 10%. Portanto, concluiu-se que a utilização do lodo da ETA Mirassol em concretos para recomposição de calçadas é viável nas porcentagens até 10%. / This work was done wishing to solve two problems: the reduction of the environmental impact caused by the inappropriate sludge disposal in Mirassol and also the reduction in the costs by reducing the volume of sludge destined to landfill and by reducing the volume of concrete small aggregates which, in spite of not representing the biggest cost of all materials involved, actually represents a cost reduction to the concessionary which needs to remake daily the pavement broke to the execution of maintenance and operation works in the water and wastewater systems. Considering the fact that Mirassol\'s water treatment plant does not have a sludge management plan, it was chosen the sun exposal method with two different times (15 and 30 days) to dry the samples of sludge. The first sample, the driest, was used in the lixiviation and solubilization experiments and the second one in the experiments involving the concrete. The objective of lixiviation and solubilization experiments was to classify the sludge according to ABNT NBR 10.004/2004. This experiments resulted manganese, plumbean and cadmium excess, especially the manganese with 400 times more concentration than the permitted by the law. So, according to these results, Mirassol\'s water treatment plant sludge was classified as Class II A. That\'s important to observe that, despite the fact that in Mirassol they use the CPA, the sludge did not shown high concentrations of aluminum. Keeping the attention on the concrete to pavements, it was noticed that doesn\'t exist in Brazil any law to discipline its confection and because of that, it was chosen the empirical method, used by the workers daily with 1:2:3 in mass. The viability analysis of the sludge use as aggregate to concrete pavement was based on the compression and traction experiments which demonstrated that, considering traces with 5%, 10% and 20% of sludge incorporated, the results was satisfactory. In fact, all of the samples had results above the aim for compression (15 MPa). On the other hand, considering the traction experiments, there\'s no references in Brazil for pavements, but it was possible to observe that the sludge addiction affected more this characteristic than the compression. However, the traction results were also satisfactory. Finally, this work recommends the utilization of 10% of sludge incorporated in concrete to pavements because they had the best results considering the compression and traction experiments.

O presente trabalho tem por objetivo avaliar a técnica de desaguamento de resíduos sólidos gerados em estações de tratamento de água utilizando tubos geotêxteis - Bags, que representam uma alternativa tecnológica para a redução do teor de umidade dos resíduos. O trabalho foi dividido em duas etapas: ensaios com Bags suspensos e com Bags dispostos sobre o solo. Nos estudos são abordadas as características mais relevantes do processo de desaguamento face às solicitações mecânicas e hidráulicas a que qualquer sistema está submetido, bem como são apresentados resultados e discussões sobre as características físico-químicas dos resíduos gerados, geocondicionados nos Bags geotêxteis e da água drenada. A técnica de desaguamento por Bags mostrou-se uma alternativa viável para a redução do teor de umidade, apresentando um melhor desempenho em relação às técnicas convencionais. Pode-se também utilizá-la em paralelo com outras técnicas já existentes para a otimização do processo de desaguamento. Ressalta-se que a correta operação da tecnologia garante a eficiência da drenagem, sendo, então, necessária a adição de polímeros como agentes coagulantes, de forma a promover a separação da fase líquida da fase sólida. Observou-se que os resíduos geocondicionados ao reduzirem o teor de umidade passam a concentrar alguns componentes químicos tais como: sílica, nitrogênio e alumínio. As dificuldades relacionadas à disposição de resíduos sólidos em estações de tratamento de água justificam esse estudo. A despeito dos resultados satisfatórios desse estudo, é importante salientar a necessidade de mais projetos que avaliem os resultados obtidos nos ensaios e o comportamento dos Bags com o passar do tempo, já que a técnica mostrou-se viável ambiental, econômica e tecnicamente. / The present study aims at evaluating the disposal process of slurry from a water treatment plant. In replacement to the conventional technique of disposing slurry in pools, a geotextile tube has been used to dehydrate and retain the slurry inside the Bag. This is achieved because the geotextile is permeable, yet soil-tight, and any excess water pressure is expelled from the tube. The work has been divided in two sets of tests: suspended Bags to define a treatment methodology and a prototype geoBag laid on the ground over a drained layer to simulate the treatment process. The mechanical, hydraulic and chemical responses associated with this process considering both solid waste and drained water contents have been evaluated and discussed. As a whole, the use of geoBags has proved to be a viable option to reduce the water content in slurry, as well as an attractive alternative to replace or to be combined with other techniques currently in use in Brazil. A critical aspect controlling the efficiency of the operation is the addition of polymers for flocculation before introducing slurry into the Bag so that liquid and solid phases are dissociated. Upon monitoring the process, it has been observed that solids retained inside the Bag exhibit concentrated levels of chemical components such as silica, nitrogen and aluminum. This study has been considered relevant in face of the environmental needs and public policy control of the disposal of solid wastes. In spite of being a promising alternative technique to slurry treatment, further investigation is needed to evaluate the trials results of this research and bag behavior as time goes by. So far, the technique has proved to be environmentally, economically and technically feasible.

This study investigated the microbiota in ten different drinking water treatment pools, particles in the Biological Activated Carbon Filtration (BACF) bed, and two mimic columns in the Cheng-Ching Lake Water Treatment Plant. Assimilable organic carbon (AOC) is one of the main nutrition sources for microbes to survive in tap water. Over growing microbes not only decrease the water quality, but also contaminate the water treatment system and distribution system. In this study, we used two molecular biology techniques, the polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE), to analyze the dynamic microbial communities and biodiversities in the drinking water cleaning system and the micorbiota that exist in the BAC and anthracite filtration pellets. The bacterial 16S rDNA sequences resulted from PCR-DGGE were compared with the data in the Ribosomal Database Project Bank to construct a phylogenetic tree which allowed us to understand the microbial communities and biodiversities in the drinking water treatment pools and the filtration pellets. The total bacterial count and PCR-DGGE profiles showed that the drinking water quality had been improved during the treating processes and most of the microbes in raw water were removed. The scanning electron microscopy clearly indicated the biofilms were developed on the pellet surface. From the mimic column studies, the PCR-DGGE profiles suggested that various microbial communities were present on different depth of the columns samples. In comparing the 16S rDNA sequences with Gene Bank, many are new category bacteria were found and most of them are unculturable. Most of these microbes belong to the beta-proteobacterium. Although many bacteria were located on the surface of the filtration pellet, the BAC and anthracite could still absorb AOC efficiently to enhance the bacteria growth. The over growing bacteria might release out and contaminate the drinking water. Therefore, we suggest that it is important to backwash the filter bed frequently in order to diminish microbes of the filtration pellet and avoid re-contaminate the drinking water.