Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2006. / Härtill 3 uppsatser.

abstract: To address sustainability issues in wastewater treatment (WWT), Siemens Water Technologies (SWT) has designed a "hybrid" process that couples common activated sludge (AS) and anaerobic digestion (AD) technologies with the novel concepts of AD sludge recycle and biosorption. At least 85% of the hybrid's AD sludge is recycled to the AS process, providing additional sorbent for influent particulate chemical oxygen demand (PCOD) biosorption in contact tanks. Biosorbed PCOD is transported to the AD, where it is converted to methane. The aim of this study is to provide mass balance and microbial community analysis (MCA) of SWT's two hybrid and one conventional pilot plant trains and mathematical modeling of the hybrid process including a novel model of biosorption. A detailed mass balance was performed on each tank and the overall system. The mass balance data supports the hybrid process is more sustainable: It produces 1.5 to 5.5x more methane and 50 to 83% less sludge than the conventional train. The hybrid's superior performance is driven by 4 to 8 times longer solid retention times (SRTs) as compared to conventional trains. However, the conversion of influent COD to methane was low at 15 to 22%, and neither train exhibited significant nitrification or denitrification. Data were inconclusive as to the role of biosorption in the processes. MCA indicated the presence of Archaea and nitrifiers throughout both systems. However, it is inconclusive as to how active Archaea and nitrifiers are under anoxic, aerobic, and anaerobic conditions. Mathematical modeling confirms the hybrid process produces 4 to 20 times more methane and 20 to 83% less sludge than the conventional train under various operating conditions. Neither process removes more than 25% of the influent nitrogen or converts more that 13% to nitrogen gas due to biomass washout in the contact tank and short SRTs in the stabilization tank. In addition, a mathematical relationship was developed to describe PCOD biosorption through adsorption to biomass and floc entrapment. Ultimately, process performance is more heavily influenced by the higher AD SRTs attained when sludge is recycled through the system and less influenced by the inclusion of biosorption kinetics. / Dissertation/Thesis / M.S. Civil and Environmental Engineering 2011

abstract: As the use of engineered nanomaterials (ENMs) in consumer products becomes more common, the amount of ENMs entering wastewater treatment plants (WWTPs) increases. Investigating the fate of ENMs in WWTPs is critical for risk assessment and pollution control. The objectives of this dissertation were to (1) quantify and characterize titanium (Ti) in full-scale wastewater treatment plants, (2) quantify sorption of different ENMs to wastewater biomass in laboratory-scale batch reactors, (3) evaluate the use of a standard, soluble-pollutant sorption test method for quantifying ENM interaction with wastewater biomass, and (4) develop a mechanistic model of a biological wastewater treatment reactor to serve as the basis for modeling nanomaterial fate in WWTPs. Using titanium (Ti) as a model material for the fate of ENMs in WWTPs, Ti concentrations were measured in 10 municipal WWTPs. Ti concentrations in pant influent ranged from 181 to 3000 µg/L, and more than 96% of Ti was removed, with effluent Ti concentrations being less than 25 µg/L. Ti removed from wastewater accumulated in solids at concentrations ranging from 1 to 6 µg Ti/mg solids. Using transmission electron microscopy, spherical titanium oxide nanoparticles with diameters ranging from 4 to 30 nm were found in WWTP effluents, evidence that some nanoscale particles will pass through WWTPs and enter aquatic systems. Batch experiments were conducted to quantify sorption of different ENM types to activated sludge. Percentages of sorption to 400 mg TSS/L biomass ranged from about 10 to 90%, depending on the ENM material and functionalization. Natural organic matter, surfactants, and proteins had a stabilizing effect on most of the ENMs tested. The United States Environmental Protection Agency's standard sorption testing method (OPPTS 835.1110) used for soluble compounds was found to be inapplicable to ENMs, as freeze-dried activated sludge transforms ENMs into stable particles in suspension. In conjunction with experiments, we created a mechanistic model of the microbiological processes in membrane bioreactors to predict MBR, extended and modified this model to predict the fate of soluble micropollutants, and then discussed how the micropollutant fate model could be used to predict the fate of nanomaterials in wastewater treatment plants. / Dissertation/Thesis / Ph.D. Civil and Environmental Engineering 2011

Submitted by Maria Medeiros (maria.dilva1@ufcg.edu.br) on 2018-08-23T12:14:13Z No. of bitstreams: 1 MARCOS HENRIQUE SILVA ARAGÃO - DISSERTAÇÃO (PPGECA) 2017.pdf: 4540927 bytes, checksum: d25472de237d384e285a54b061998c1e (MD5) / Made available in DSpace on 2018-08-23T12:14:13Z (GMT). No. of bitstreams: 1 MARCOS HENRIQUE SILVA ARAGÃO - DISSERTAÇÃO (PPGECA) 2017.pdf: 4540927 bytes, checksum: d25472de237d384e285a54b061998c1e (MD5) Previous issue date: 2017-08 / Capes / No processo de produção do álcool são gerados até 15 litros de vinhoto por litro de álcool produzido. O vinhoto é um rejeito caracterizado por apresentar elevadas concentrações de material orgânico e nutrientes. Essas características fazem do vinhoto um substrato adequado para a produção de proteína unicelular (PUC) em sistemas de lodos ativados mediante a produção de excessiva de biomassa bacteriana, que é constituída por cerca de 60 -70 % de proteínas, podendo ser empregada como ração animal. O lodo do tipo PAO, produzido em sistemas EBPR, é caracterizado por ter uma taxa de decaimento bacteriano notadamente inferior em comparação aos microrganismos ordinários de lodos ativados. Isso representa uma vantagem para a produção de PUC, tanto pela manutenção de uma quantidade maior de biomassa, quanto pelos menores requisitos de oxigênio para a oxidação das células mortas. O desenvolvimento desses microrganismos no lodo exige uma mudança operacional no regime de aeração, introduzindo uma fase anaeróbia em cada batelada, na qual é realizada a alimentação com o substrato. Este trabalho teve como objetivos: avaliar e comparar a produção máxima de PUC a partir do vinhoto em sistemas de lodos ativados em função da idade de lodo tanto para os organismos heterotróficos ordinários (OHO) como para organismos acumuladores de polifosfato (PAO), determinar a eficiência de remoção de material orgânico e de nutrientes, a determinação das composições dos lodos e a determinação das principais constantes cinéticas e estequiométricas de cada um deles. Foi aplicada a respirometria como ferramenta para a caracterização cinética do consumo do material orgânico e adotada a teoria de lodos ativados proposta por van Haandel e Marais (1999). Foram operados e monitorados dois reatores em bateladas sequenciais com idade de lodo de 8 dias, sendo um deles submetido a uma interrupção no regime de aeração, introduzindo uma fase anaeróbia no início de cada batelada visando ao desenvolvimento de um lodo do tipo PAO. Os resultados obtidos demonstraram que houve uma produção satisfatória de lodo em ambos os reatores, bem como uma elevada remoção de material orgânico no efluente. Não se observou uma remoção em excesso de fósforo ou uma elevada fração de fósforo incorporada ao lodo produzido no sistema submetido à modificação no regime de aeração, além disso não foi observada uma produção mais elevada de lodo nesse sistema, indicando que o lodo PAO não foi produzido. A determinação do comportamento cinético dos lodos demonstrou que existe um elevado potencial de produção de PUC em sistemas lodos ativados tratando vinhoto, embora essa produção seja limitada pela capacidade de oxigenação dos aeradores e esteja condicionada ao avanço desses equipamentos. / In the process of producing the alcohol, up to 15 liters of vinasse per liter of alcohol produced are generated. The vinasse is a reject characterized by high concentrations of organic material and nutrients. These characteristics make vinasse a suitable substrate for the production of single cell protein (SCP) in activated sludge systems through the production of excessive bacterial biomass, which consists of about 60-70% of proteins, can be used as animal feed. The PAO-type sludge, produced in EBPR systems, is characterized by having a markedly lower bacterial decay rate compared to ordinary activated sludge microorganisms. This represents an advantage for the production of PUC, both by maintaining a higher amount of biomass and by lower oxygen requirements for the oxidation of dead cells. The development of these microorganisms in the sludge requires an operational change in the aeration regime, introducing an anaerobic phase in each batch, in which the feeding with the substrate is carried out. The objective of this work was to evaluate and compare the maximum production of SCP from vinasse as a function of sludge age in activated sludge systems for both ordinary heterotrophic organisms (OHO) and polyphosphate accumulating organisms (PAO). Efficiency of removal of organic matter and nutrients, determination of the sludge compositions and determination of the main kinetic and stoichiometric constants of each of them. It was applied the respirometry as a tool for the kinetic characterization of organic material consumption and adopted the theory of activated sludge proposed by van Haandel and Marais (1999). Two reactors were operated and monitored in sequential batches with a sludge age of 8 days, one of them being submitted to an interruption in the aeration regime, introducing an anaerobic phase at the beginning of each batch, aiming at the development of a PAO type sludge. The results showed that there was a satisfactory production of sludge in both reactors, as well as a high removal of organic material in the effluent. There was no excess removal of phosphorus or a high fraction of phosphorus incorporated into the sludge produced in the system submitted to the modification in the aeration regime, in addition no higher sludge production was observed in this system, indicating that the PAO sludge was not produced. The determination of the kinetic behavior of the sludge showed that there is a high potential in the PUC production in activated sludge treatment systems, although this production is limited by the oxygenation capacity of the aerators and is conditioned to the advance of these equipment.

Abstract Wastewater treatment is facing challenges due to the stricter legislation and increasing variety in the quantity and quality of the influent. In addition, for economic reasons the use of resources should be efficient. Therefore new automated monitoring tools and methods along with intelligent use of the gathered data are required to increase knowledge on the treatment process and to receive predictive information on the quality of the effluent that can be used to assist in optimizing the process operation. Predicting the effluent quality is difficult, as the complex treatment process includes several simultaneous nonlinear mechanisms and the relevant continuous information on the floc morphology is commonly missing, even though the flocculation process holds the key role in efficient wastewater treatment. Automated optical monitoring is able to reveal new valuable information on wastewater continuously, fast, objectively, and with minimal labor contribution. The main aim of this research was to develop predictive models for the quality parameters of treated wastewater at two full-scale wastewater treatment processes utilizing optical monitoring results. The actual predictive information was enabled using the measurements from the beginning of the process in model development alone. The optimal subsets of the model variables were sought by variable selection methods. The research also shows how utilization of the process measurements and the optical monitoring variables separately and together affect the modeling accuracy. The quality of the effluent in municipal and industrial wastewater treatment processes can be predicted in varying operating conditions by utilizing optical monitoring and process measurements. The prediction accuracy is sufficient to reveal the level of and changes in effluent quality. Thus, process operation can be optimized, more efficiently purified wastewater can be achieved, and environmental damage, health-related risks, and economic losses can be minimized. / Tiivistelmä Jätevedenkäsittely kohtaa tulevaisuudessa haasteita tiukentuvan lainsäädännön sekä lisääntyvän jätevesimäärän ja laatuvaihteluiden vuoksi. Lisäksi taloudellisista syistä resurssien käytön pitäisi olla mahdollisimman tehokasta. Tämän vuoksi tarvitaan uusia automaattisia monitorointivälineitä ja -menetelmiä sekä kerätyn datan älykästä käyttöä lisäämään tietoa käsittelyprosessista ja ennustamaan käsitellyn jäteveden laatua prosessin ohjauksen optimoimiseksi. Käsitellyn jäteveden laadun ennustaminen on vaikeaa, sillä monimutkainen käsittelyprosessi sisältää useita yhtäaikaisia epälineaarisia mekanismeja ja olennainen jatkuva-aikainen tieto flokkien morfologiasta puuttuu, vaikka flokkausprosessi on keskeisessä asemassa jätevedenpuhdistuksen tehokkaan toiminnan kannalta. Automaattisen optisen monitoroinnin avulla saadaan uutta hyödyllistä tietoa jätevedestä jatkuva-aikaisesti, nopeasti, objektiivisesti ja vähäisellä työpanoksella. Tämän tutkimustyön päätavoite oli kehittää ennustemalleja kahden täysikokoisen jätevesilaitoksen käsitellyn jäteveden laatuparametreille hyödyntäen automaattista optista monitorointia. Malleissa käytettiin vain prosessin alkuosan mittauksia, jotta malleilla olisi todellinen kyky ennakoida käsitellyn jäteveden laatu. Mallien optimaaliset tulomuuttujat etsittiin muuttujavalinta-algoritmeilla. Tutkimus näyttää myös, miten prosessimittausten ja optisen monitoroinnin muuttujien hyödyntäminen yhdessä ja erikseen vaikuttaa mallien tarkkuuteen. Optisen monitoroinnin hyödyntäminen yhdessä prosessimittausten kanssa mahdollistaa käsitellyn jäteveden laadun ennustamisen vaihtelevissa olosuhteissa sekä teollisessa että kunnallisessa jätevedenkäsittelylaitoksessa. Mallinnustarkkuus on riittävä laatuparametrien tason ja muutosten esittämiseen ja käytettäväksi apuna prosessin ohjauksessa. Tällöin jäteveden puhdistusprosessi tehostuu ja ympäristövahingot, terveysriskit ja taloudelliset menetykset voidaan minimoida.

Thesis (MTech (Electrical Engineering))--Cape Peninsula University of Technology, 2009. / This project was started as a result of strict environmental and health regulations together with a demand for cost effective operation of wastewater treatment plants (WNTPs). The main aim of this project is how to keep effluent concentration below a prescribed limit at the lowest possible cost Due to large fluctuations in the quality and quantity of the influent concentrations, traditional control methods are not adequate to achieve this aim The major drawback with these methods is that the disturbances affect the process before the controller has time to correct the error (Olsson and Newell, 1999: 454). This problem IS addressed through the use of modern control systems Modern control systems are model based predictive algorithms arranged as feed-forward controllers (Olsson and Newell, 1999: 454) Normally a controller is equipped with a constant set point; the goal In this project IS to calculate an optimal DO trajectory that may be sampled to provide a varying optimal set-point for the Activated Sludge Process. In this project an optimal control problem is formulated usmq 00 concentration as a control variable This requires a model of the process to be controlled, a mathematical expressions of the limitations on the process input and output variables and finally the objective functional which consists of the objectives of the control. The structures of the Benchmark plant (developed within the COST 682 working group) and the Athlone WWTPs are used to implement this optimal control strategy in MATLAB, The plant's full models are developed based on the mass balance principle incorporating the activated sludge biological models. ASM1, ASM2 ASM2d and ASM3 (developed by the IWA. working groups) To be able to develop a method that may later on be used ~or online control. the full models are reduced based on the technique in Lukasse (1996) To ensure that the reduced models keep the same prediction capabilities as the full models paran-eters of the reduced models are calculated based on the Least Squares principle. The formulated optimal control problem IS solved based on the decomposition-coordination method that involves time decomposition 111 a two layer structure, MATLAB software is developed to solve the problems for parameter estimation full and reduced model simulation and optimal control calculation for the considered different cases of plant structures and biological models, The obtained optimal DO trajectories produced the effluent state trajectories within prescribed requirements. These DO trajectories may be implemented in different SCADA systems to be tracked as set points or desired trajectories by different types of controllers.

Thesis (MTech (Chemical Engineering))--Cape Peninsula University of Technology, 2016. / Polymers used as flocculants in the secondary sludge dewatering process are one of the most expensive inputs in these plants. The disadvantage is that these polymers cannot be recycled. Currently, controlling of polymer dosing rate is done by trial and error method. It has been shown that huge savings can be made by optimising the polymer dosing using rheological properties. It is not an easy task to optimise this process because of changing sludge characteristics on a daily, seasonal and annual basis. To try and optimise polymer dosing and polymer concentration, the variation in rheological properties needs to be understood first. The correlation between the process parameters and the rheological properties needs to be determined. There is currently no database of rheological properties of secondary wastewater sludge feeding belt filter presses available. To address these issues, a 12 week assessment of the rheological properties of the sludge feed to the belt filter press before and after conditioning in four wastewater treatment plants in Cape Town was conducted. The rheological properties were determined using an MCR-51 rheometer with parallel plate geometry under controlled temperature. After concluding the assessment, a 3-level Box-Behnken factorial trial was conducted at Plant K wastewater treatment plant to statistically analyse the correlation and/or interactions between the process parameters (sludge feed flow rate, polymer dosing concentration, polymer dosing rate and belt press speed) and the rheological properties of the sludge to optimise the plant performance.

Por razões técnicas e ambientais, o lodo gerado no tratamento de águas para abastecimento público deve ser adequadamente tratado antes de ser disposto no meio ambiente. Uma alternativa é a disposição do lodo de ETA em ETE, o que dispensa a implantação da linha de tratamento do lodo na ETA. O objetivo deste trabalho foi estudar os impactos ocorridos na ETE ABC, estação de lodos ativados convencional operada pela SABESP, devido ao recebimento do lodo da ETA Rio Grande. Trata-se de caso particular, pois envolve instalações reais, e pelo fato de a ETA apresentar vazão próxima de três vezes a vazão da ETE (vazão de lodo corresponde a 0,1% da vazão da ETE). Os dados utilizados incluem variáveis de qualidade do efluente (DBO, DQO, SST, SSV, nitrogênio amoniacal e total, fósforo e ferro) e do lodo (sólidos), e parâmetros operacionais das unidades da ETE (vazões, taxas de aplicação superficial e de sólidos, idade do lodo, tempo de detenção, entre outros). Foi possível analisar o processo de tratamento na ETE e comparar seu desempenho entre dois períodos: controle (anos de 2005 e 2006) e com lodo (janeiro de 2007 a março de 2008). Nestes períodos, a ETE operou com 50% de sua capacidade (taxas de aplicação abaixo dos valores de projeto), idade do lodo de 4 dias e taxa de reciclo em torno de 80%. No período com lodo, as variáveis que apresentaram maior aumento de concentração no esgoto afluente foram SST, SSV, fósforo e ferro; o lodo da ETA contribuiu para maiores eficiências de tratamento da fase líquida na ETE, uma vez que houve a manutenção da qualidade do efluente final, nos níveis exigidos pela legislação, mesmo com o aumento das concentrações afluentes. Este aumento de eficiência foi mais acentuado para o fósforo (de 52% para 88%), e maior no tratamento primário, com variações nos parâmetros operacionais que não influíram negativamente no desempenho das unidades. No tratamento de lodo, o maior impacto causado foi o aumento na produção final de lodo (de 50 t/d para 76 t/d). Tais conclusões são então favoráveis ao lançamento de lodos de ETA convencional em ETE de lodos ativados convencional, mesmo nos casos em que a vazão tratada na ETA exceda em muito a vazão da ETE. / For technical and environmental reasons, sludge from water treatment plants should be properly treated before being discharged into the environment. An emerging practice is the disposal of such sludge in WWTP, an alternative that does not require the installation of sludge treatment facilities in the WTP. The main purpose of this research was to study the impacts at the ABC WWTP, an activated sludge process facility operated by SABESP and located in São Paulo, Brazil, due to receiving sludge from the Rio Grande WTP, also located in the same region. It is a particular case due to the fact that the WTP provides a flow of three times the flow treated in the WWTP (sludge flow is 0,1% of WWTP flow). The used data include effluent quality variables (BOD, COD, TSS, VSS, ammonia and total nitrogen, phosphorus and iron), sludge (solids) and WWTP units operational parameters (flow, surface and solid application rates, sludge retention time, hydraulic detention time, among others). It was possible to analyze the treatment process at the WWTP and compare its performance between two periods: control (years 2005 and 2006) and with sludge (from January 2007 to March 2008). In these periods, the WWTP worked with half of its capacity (all loading rates stayed below design values), sludge retention time of 4 days and recycle rate around 80%. In the with sludge period, the quality variables with the highest inflow concentration increase were TSS, VSS, phosphorus and iron. During the same period, the WTP sludge contributed to greater efficiencies in the WWTP treatment process, since the effluent quality was maintained under levels legally required, even with the increase of influent concentrations. This fact is mostly evident in the case of phosphorus (from 52% to 88%), and higher in primary treatment, with changes in operational parameters that did not adversely affect the units performances. In solid phase treatment, the most important impact was the increase in final sludge production (from 50 t/d to 76 t/d). These conclusions are then favorable to the disposal of sludge from conventional WTP in an activated sludge WWTP, even in cases in which the flow treated in the WTP far exceeds the WWTP flow.

O processo de tratamento de esgoto por lodo ativado pode ser adaptado para o recebimento de maior carga orgânica ou para a remoção de nitrogênio por meio da introdução de suportes plásticos móveis, em um processo conhecido por IFAS Integrated Fixed-Film Activated Sludge. O objetivo do projeto é avaliar comparativamente os desempenhos dos sistemas de lodo ativado e IFAS na remoção de matéria orgânica e nitrogênio de esgoto doméstico, associados à variação da idade do lodo com referência na biomassa suspensa. O efeito da adição de suportes plásticos móveis em sistemas existentes de lodo ativado é avaliado como forma de subsidiar análises de viabilidade de emprego dessa solução para a ampliação e adaptação de estações de tratamento de esgotos domésticos. A pesquisa foi desenvolvida em escala piloto, mantendo dois sistemas em funcionamento em paralelo, um representando um sistema de lodo ativado com remoção de nitrogênio e outro idêntico, exceto para a introdução dos suportes plásticos móveis. Desta forma, foi possível atribuir a diferença nos resultados à presença de biomassa aderida. Foram utilizados elementos suporte com área superficial específica de 300 m²/m³ e fração de enchimento de 50%. Ambos os sistemas foram mantidos em operação estável e eficiente, considerando a remoção de matéria orgânica. No entanto, o sistema IFAS teve melhor desempenho na remoção de nitrogênio em todas as fases experimentais, confirmando as vantagens antecipadas. Os resultados foram verificados em termos de taxas de aplicação previstas para cada porção de biomassa, de acordo com as idades do lodo estudadas. / The activated sludge wastewater treatment process can be retrofitted to either receive larger organic loads or for nitrogen removal by introducing plastic media carriers, in a process known as IFAS Integrated Fixed-Film Activated Sludge. The project aims to comparatively assess the performances of activated sludge and IFAS systems in removing organic matter and nitrogen from domestic sewage, associated to the variation of the sludge age with reference to the suspended biomass. The effect of adding plastic media carriers on existing activated sludge systems is evaluated as a subsidy for prefeasibility analysis of using this solution for the upgrading and retrofitting of municipal wastewater treatment plants. The study was developed on a pilot scale, operating two systems in parallel, representing an activated sludge system with nitrogen removal and another identical system except for the introduction of plastic media carriers. Thus, it was possible to assign the difference in results to the presence of attached biomass. Carriers were used with 300 m²/m³ specific surface area and 50% filling fraction. Both systems were kept under stable and efficient operation considering the removal of organic matter. However, the IFAS system had better performance at removing nitrogen in all experimental phases, confirming the anticipated advantages. The results were verified in terms of application rates expected for each portion of biomass in accordance with the sludge ages studied.

FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / O descarte de efluentes tÃxteis em Ãguas superficiais representa um sÃrio problema ambiental e de saÃde pÃblica devido, principalmente, à presenÃa de corantes na sua composiÃÃo, muitos dos quais sÃo potencialmente tÃxicos e carcinogÃnicos. A remoÃÃo de cor e a mineralizaÃÃo de seus subprodutos à uma das maiores dificuldades enfrentadas pelas estaÃÃes de tratamento de efluentes das indÃstrias desse segmento. Nesta pesquisa, buscou-se avaliar o tratamento de efluentes tÃxteis em sistemas anaerÃbios de um e dois estÃgios, estudar opÃÃes de pÃs-tratamento por processos biolÃgicos aerÃbios e de oxidaÃÃo avanÃada, e utilizar testes de ecotoxicidade no estudo dos diversos efluentes produzidos. Foram realizados experimentos com sistemas anaerÃbios de um (R1) e dois estÃgios (R2) tratando esgotos tÃxteis real e sintÃticos. Nestes experimentos, foram avaliados o efeito da concentraÃÃo do corante, concentraÃÃo do doador de elÃtrons externo, o tempo de detenÃÃo hidrÃulica (TDH) e o efeito do mediador redox antraquinona-2,6-dissulfonato (AQDS) na eficiÃncia de descoloraÃÃo. Outros dois sistemas anaerÃbios de um estÃgio (R3 e R4) foram operados em paralelo, alimentados com esgoto tÃxtil real com TDH de 12h a fim de avaliar o efeito do AQDS na descoloraÃÃo de efluentes reais. Durante o pÃs-tratamento aerÃbio, foi avaliada a aplicaÃÃo de um reator de lodos ativados em batelada seqÃencial com ciclo total de 24h, operando com os efluentes, sintÃtico e real, previamente tratados no reator UASB. Avaliou-se, tambÃm, a aplicaÃÃo do processo de oxidaÃÃo avanÃada (POA) do tipo UV/H2O2 como opÃÃo de pÃs-tratamento dos efluentes tÃxteis tratados no reator UASB, tanto em relaÃÃo à descoloraÃÃo quanto na mineralizaÃÃo dos subprodutos gerados na reduÃÃo dos corantes. A avaliaÃÃo da toxicidade dos efluentes foi realizada pelos ensaios de toxicidade aguda utilizando a Daphnia magna como organismo teste. Os resultados dessa pesquisa revelaram que o sistema anaerÃbio de dois estÃgios mostrou-se mais estÃvel que o sistema de um estÃgio quando operado como o esgoto real e sintÃtico com os corantes Congo Red (CR) e Reactive Black 5 (RB5) e mais eficiente para o corante RR2 na ausÃncia de AQDS. Entretanto, na presenÃa do AQDS a eficiÃncia de descoloraÃÃo do Reactive Red 2 (RR2) foi elevada para os dois sistemas, mascarando o efeito da separaÃÃo de fase. Para o efluente tÃxtil real, nÃo foi verificado efeito algum da aplicaÃÃo do AQDS no R3, mesmo em baixo TDH e limitada concentraÃÃo de doador de elÃtrons. O pÃs-tratamento dos efluentes real e sintÃticos no reator aerÃbio foi capaz de reduzir a DQO abaixo de valor exigido pela portaria 154/02 da SEMACE. O processo de oxidaÃÃo avanÃada com UV/ H2O2 mostrou-se eficaz na remoÃÃo de cor e DQO dos efluentes tÃxtil real e sintÃticos. Os testes de toxicidade aguda ratificaram o potencial tÃxico dos efluentes tÃxteis e os subprodutos de sua degradaÃÃo assim como a capacidade de mineralizaÃÃo das aminas em sistemas seqÃenciais anaerÃbio/aerÃbio. / Disposal of textile effluents in surface waters represents a serious environmental and public health problem mainly due to the presence of dyes in their composition, many of which are potentially toxic and carcinogenic. The color removal and mineralization of byproducts is the major difficulty faced by the wastewater treatment plants of these industries. This thesis studied the treatment of textile effluents in one-stage and two-stage anaerobic systems, post-treatment options by using aerobic biological and advanced oxidation processes, and use the ecotoxicity tests for the various effluents produced. Experiments were performed in one-stage (R1) and two-stage (R2) anaerobic systems treating real and synthetic textile wastewaters. In these experiments, we evaluated the dye concentration effect, as well as external electron donor concentration, hydraulic retention time (HRT) and the redox mediator anthraquinone-2,6-disulfonate (AQDS) effect on color removal efficiency. Two other one-stage anaerobic systems (R3 and R4) were operated in parallel at the HRT of 12 hours and fed with real textile wastewater to assess the AQDS effect on the decolourisation of real textile effluents. During the aerobic post-treatment, we evaluated the application of sequencing batch reactor (SBR) with 24 hours total cycle to treat synthetic and real textile wastewaters pre-treated in the UASB reactor. We also evaluated the application of UV/H2O2 advanced oxidation process (AOP) to treat real textile wastewaters pre-treated in the UASB reactor, both in terms of color removal and mineralization of byproducts generated upon dye reduction. The evaluation of the effluents toxicity was performed by acute toxicity tests using Daphnia magna as test organism. The results revealed that the two-stage anaerobic system was more stable than the one-stage system for both real and the synthetic dyes Congo Red (CR) and Reactive Black 5 (RB5), and more efficient for the dye RR2 in absence of AQDS. However, in the presence of AQDS, color removal efficiency of RR2 was higher for both systems, masking the effect of phase separation. For real textile wastewater, it was not observed any effect of the AQDS application on R3, even when a short HRT or low electron donor concentration was applied. The aerobic and AOP post-treatments were able to reduce the effluents COD to values lower than the limits defined at the Legislation n 154 of SEMACE. The UV/H2O2 AOP-type was effective in removing color and COD from both real and synthetic textile effluents. The acute toxicity tests revealed the toxic potential of textile effluents and their by-products as well as the aromatic amines mineralization in anaerobic/aerobic systems.