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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
111

Systems approaches to enhance performance and applicability of microbial fuel cells

Boghani, Hitesh Chandubhai January 2014 (has links)
Wastewater treatment is an energy intensive process and sustainable processes/technologies for the treatment of wastewaters need to be considered. One such contender might be the microbial fuel cell (MFC), a subset of bioelectrochemical system (BES) which generates electricity in the process of electrogenic (generating electrons) degradation of soluble organic contaminants present in the water (or wastewater) by electrogens (electron producing bacteria) at the anode in absence of oxygen. Several issues related to the power performance (also somewhat linked to the cost) of MFCs exist causing barriers in the deployment of up-scaled MFC system and the continual research from a multitude of discipline is focusing on overcoming these issues. Implementation of an MFC system for wastewater treatment would require a large array of MFCs to meet the treatment capacity of the wastewater treatment plant. Commissioning and continual operation of such MFCs would require rapid and cost-effective start-up and improvement in their performance. Optimisation of the power performance is addressed through a systems approach in this study, where improvement in the performance is sought through the system design and control strategies applied to the MFCs. The start-up rate of MFCs has been reduced by 45% using maximum power point tracking (MPPT), which is believed to be cost-effective as exogenous energy (such as in the case of poised-potential) is not required for the rapid start-up. The control of MFC power would need to be considered when up-scaled MFC system is realised. The controller implementation benefits from linearised system models. The viability of such piecewise linearisation of the nonlinear MFC system was demonstrated and the data were shown to be reasonably represented by the 1st order process models throughout its operating range. The occurrence of voltage reversal during stack operation of MFCs is a concern in large arrays particularly, and has been shown to be avoidable by adopting the hybrid stack connectivity. Further enhancement of the performance was sought through the detailed design and fluid dynamics modeling to obtain highly mixed anolyte at low input power, using improved helical anodes which increased the MFC performance at all the tested flow rates (1, 3 and 8 mL min-1) compared to previously studied helical anodes. The up-scaling of MFCs by modularisation was demonstrated and it was shown that the use of improved helical anodes can increase the modular length of the MFC without compromising the power performance. Aggregated power produced from the multi-module MFC (containing 5 modules) was 28.05 ± 3.5 mW (19.75 ± 2.47 W m-3) with an PhD Thesis – Hitesh Chandubhai Boghani 2014 V individual MFC power of 5.61 ± 0.7 mW, when fed with 10 mM sodium acetate at 3 mL min-1 flow rate and at 22 ± 3 °C. So, this thesis presents the strategies for improvement in the performance of MFCs for their applications in wastewater treatment and such strategies may also be transferable to their other applications.
112

Vers un procédé Fenton hétérogène pour le traitement en continu d’eau polluée par des polluants pharmaceutiques / To a heterogeneous Fenton process for continuous treatment of pharmaceutical wastewaters

Velichkova, Filipa Aleksandrova 20 January 2014 (has links)
Ce travail a pour objectif de développer un procédé couplant séparation membranaire et oxydation (photo-) Fenton hétérogène pour l’élimination du paracétamol dans l’eau. La réaction a d’abord été étudiée avec le fer en solution à pH acide (2,6) pour servir de référence aux études hétérogènes ultérieures. La méthodologie des plans d’expériences a permis de déterminer les paramètres influents (parmi température, concentrations d’oxydant et de catalyseur) et leurs interactions, et de modéliser les performances du procédé homogène. Des oxydes de fer sous la forme de particules nano- et micro-structurées (hématite, maghémite et magnétite) ou supportés sur zéolithes (type MFI ou BEA) ont ensuite été testés comme catalyseurs de l’oxydation Fenton. Pour chaque système étudié, on a évalué la conversion du polluant et du Carbone Organique Total (COT), mais aussi la stabilité du catalyseur : quantité de fer lixivié et activité du métal passé en solution (pour découpler la contribution du mécanisme homogène associé). L’effet des paramètres opératoires a ensuite été à nouveau évalué pour les catalyseurs sélectionnés (magnétite nanostructurée et Fe/MFI). Pour l’oxyde non supporté, l’étude met en évidence le rôle positif d’une augmentation de la température. A température et pH donnés, le rapport initial [oxyde de fer] / [H2O2] apparaît aussi comme le paramètre essentiel qui contrôle le taux de minéralisation, avec une inhibition de la réaction lorsque H2O2 est en trop large excès. Au contraire, pour le catalyseur Fe/MFI, une augmentation de la concentration d’oxydant se révèle bénéfique (sa consommation étant pratiquement totale dans tous les cas), et il y a peu d’effet de la température. Par ailleurs, la magnétite se révèle efficace à pH acide uniquement, tandis que le catalyseur supporté présente la même activité avec ou sans acidification préalable. L’irradiation UV améliore les performances de ces deux catalyseurs avec un abattement du COT en solution jusqu’à 70% en 5 heures, contre 98% pour le système homogène dans des conditions similaires. Les premiers tests en continu avec des particules de Fe/MFI retenues par une membrane d’ultrafiltration immergée sont prometteurs, puisque l’activité est restée stable pendant plus de 40 h. / This work aims to develop a process coupling membrane separation and heterogeneous (photo-) Fenton oxidation for the elimination of paracetamol in water. The reaction was first studied with dissolved iron in acidic solution (pH 2.6), as a reference for the subsequent heterogeneous studies. The methodology of experimental design was used to determine the significant parameters (including temperature, oxidant and catalyst concentrations) and their interactions, and to model the performance of the homogeneous process. Iron oxides as nano- and micro-structured particles (hematite, maghemite and magnetite) or supported on zeolites (MFI or BEA type) were then tested as catalysts for the Fenton oxidation. For each studied system the conversions of pollutant and Total Organic Carbon (TOC) were evaluated, as well as the catalyst stability: amount and activity of leached iron (in order to decouple the contribution of homogeneous mechanism). The effect of process parameters was then again evaluated for the selected catalysts (nanostructured magnetite and Fe/MFI). For magnetite, the study reveals a positive effect of temperature. At given temperature and pH, the initial ratio of [iron oxide] to [H2O2] also appears as a key parameter that controls the mineralization yield, with an inhibition of the reaction when H2O2 is in large excess. Conversely, for Fe/MFI catalyst, the increase in oxidant concentration is beneficial (oxidant being almost fully consumed in all cases), and temperature has a poor effect. Furthermore, magnetite is only effective at acidic pH, while supported catalyst exhibits same activity with or without prior acidification. UV irradiation improves the performance of these catalysts with a reduction of TOC in solution up to 70% within 5 hours, against 98% for the homogeneous system under similar conditions. The results of the first continuous test, performed with Fe/MFI particles retained by a submerged ultrafiltration membrane, are promising: a stable activity has been observed for over 40 h.
113

Utilização de lodo de efluente doméstico: efeitos na produtividade agrícola e em alguns aspectos ambientais

Breda, Carlos Cesar [UNESP] 21 November 2003 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:31:35Z (GMT). No. of bitstreams: 0 Previous issue date: 2003-11-21Bitstream added on 2014-06-13T21:02:52Z : No. of bitstreams: 1 breda_cc_dr_botfca.pdf: 997977 bytes, checksum: 2739d3d49d29284c484046062466ce67 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O objetivo deste trabalho foi avaliar os efeitos da aplicação do lodo de esgoto proveniente de uma pequena estação de tratamento, localizada na Fazenda Experimental Lageado, Faculdade de Ciências Agronômicas–UNESP, Botucatu, SP, Brasil, na produtividade agrícola e características de plantas de milho, bem como seus impactos nas características do solo e na qualidade da água drenada para o freático. O delineamento experimental foi constituído por blocos ao acaso, com parcelas subdivididas no tempo (Ensaios), num total de 6 tratamentos, 4 blocos e 4 ensaios, sendo T1 (testemunha, sem fertilização); T2 (10t ha-1 de lodo seco); T3 (20t ha-1 de lodo seco); T4 (30t ha-1 de lodo seco); T5 (40t ha-1 de lodo seco) e T6 (adubação mineral). Os ensaios foram assim definidos: E1 (cultivo de verão instalado em 11/2000); E2 (cultivo de inverno instalado em 06/2001); E3 (segundo cultivo de verão instalado em 11/2001) e E4 (segundo cultivo de inverno instalado em 05/2002). Foi utilizado o milho como cultura teste. Os parâmetros avaliados no campo foram altura das plantas, diâmetro do colmo e número de folhas em três épocas diferentes, além da análise foliar. Após a colheita das espigas foram avaliados os componentes de produção: massa sem palha, comprimento, diâmetro e número de fileiras das espigas; massa da palha; diâmetro... / The objective of this study was to evaluate the effects of the use of sewage sludge, coming from a small treatment station, located in Lageado Experimental Farm, Agronomic Sciences College - UNESP, Botucatu, SP, Brazil, on productivity and characteristics of corn plants, as well as its impact on soil characteristics and quality of drained water. The experimental design constituted of randomized blocks, with split plots in time (Assays), with 6 treatments, 4 blocks and 4 assays. The treatments were T1 (control, without fertilization); T2 (10t ha-1 of dry sludge); T3 (20t ha-1 of dry sludge); T4 (30t ha-1 of dry sludge); T5 (40t ha-1 of dry sludge) and T6 (mineral fertilizer). The assays were defined as: E1 (first summer plantation, installed in 11/2000); E2 (first winter plantation, installed in 06/2001); E3 (second summer plantation, installed in 11/2001), and E4 (second winter plantation, installed in 05/2002). The parameters evaluated were height of plants, stem diameter and number of leaves, besides leaves chemical analysis. After harvesting of corn spikes, the production components were evaluated: spikes without straw; spike length, diameter and line number; straw weight; corncob diameter; number of spikes; weight of 1000 grains and grains for spike). Moreover, the corn productivity at 13% of... (Complete abstract click electronic access below)
114

Avaliação do potencial de reuso agrícola do efluente de uma estação de tratamento de esgoto com alagados construídos

Giafferis, Giselda Passos [UNESP] 11 November 2011 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:31:39Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-11-11Bitstream added on 2014-06-13T20:42:20Z : No. of bitstreams: 1 giafferis_gp_dr_botfca.pdf: 2278528 bytes, checksum: bc34acd935bbc156fa3e47bced1d5556 (MD5) / Os sistemas de alagados construídos (SACs) são projetados como passivos de depuração, constituídos por lagoas ou canais, compostos por plantas aquáticas livres ou fixas em substratos como areia, solo ou cascalho, onde ocorre a proliferação de biofilmes que agregam populações variadas de micro-organismos presentes nas águas residuárias. O uso combinado de tecnologias simples e de baixo custo como os reatores anaeróbios seguidos de alagados construídos como pós-tratamento, tem sido de interesse para o saneamento em pequenas comunidades. A pesquisa ocorreu em uma planta de tratamento de esgoto real do Departamento de Água e Esgoto de Bauru, localizada no Distrito de Tibiriçá, com vazão média de 4,8L/s, composta por processo de filtro anaeróbio de fluxo ascendente, seguido de sistemas de alagados construídos em paralelo. Como objetivo deste trabalho, buscou-se avaliar a eficiência dos três sistemas de alagados construídos, com tipos de plantas diferentes e analisar quantitativa e qualitativamente os efluentes nas várias etapas do processo de tratamento, para verificar suas eficiências e a possibilidade de reúso do efluente final na agricultura. Diante dos resultados obtidos, observou-se que houve satisfatória remoção de matéria orgânica, com concentração média de 36 e 39 mg/L, nas fases 1 e 2 de operação,respectivamente, atendendo os valores exigidos pela legislação para padrões de emissão, mesmo recebendo concentrações afluentes elevadas, de efluentes não doméstico por batelada, o qual não foi previsto em projeto. Constatou-se que as concentrações de nutrientes, como nitrogênio e fosfato foram altas em todo o sistema e a eficiência de remoção de nitrogênio amoniacal esteve muito abaixo do esperado, não atendendo a legislação que exige lançamentos... / The constructed wetland systems are designed as passive purification, consisting of ponds or channels, composed of aquatic plants free or fixed on substrates such as sand, soil or gravel, where the proliferation of biofilms is that aggregate diverse populations of micro- organisms present in wastewater. The combined use of simple and inexpensive as the anaerobic reactors followed by constructed wetlands as post-treatment has been of interest for sanitation in small communities. The research took place in a sewage treatment plant's actual Department of Water & Sewer Bauru, located in the District of Tibiriçá with average flow of 4.8 L/s made by a process of upflow anaerobic filter, followed by systems constructed wetlands in parallel. As objective of this study we sought to evaluate the effectiveness of three constructed wetland systems, with different types of plants and analyze quantitative and qualitative effluent at various stages of treatment to monitor their effectiveness and the possibility of reuse in the final effluent agriculture. Considering the results obtained, it was observed that there was satisfactory removal of organic matter, with a mean concentration of 36 and 39 mg/L, phases 1 and 2 operations, respectively, given the values required by law for emission standards, even with affluent high concentrations of non-domestic waste per batch, which was not foreseen in the project. It was found that concentrations of nutrients such as nitrogen and phosphate were high throughout the system and the removal efficiency of ammonia nitrogen was much lower than expected, does not meet the law requires that releases up to 20 mg/L. The results obtained for nitrogen and phosphate in effluent from constructed wetland systems, it is concluded that the system is also functioning as a secondary... (Complete abstract click electronic access below)
115

Microbial communities in an anaerobic membrane bioreactor (AnMBR) treating domestic wastewater at ambient temperatures in a temperate climate

Penfield, Tyler January 1900 (has links)
Master of Science / Department of Civil Engineering / Prathap Parameswaran / The ever-increasing demand for water, food, and energy and the simultaneous diminishment of our planets’ ecosystems wrought by humans have prompted a more sustainable approach to engineering the built environment. Wastewater treatment systems stand at the interface that connects the built and natural environment where potential solutions for resource and environmental issues exist. Wastewater treatment technologies can address issues involving water, food, energy, and environmental regulation when resources are properly captured from the wastewater while it’s being treated. This way of thought allows wastewater to be perceived as a source of valuable products rather than an obligate waste stream. For this reason, anaerobic wastewater treatment is progressively being considered because of its ability to improve energy and resource recovery, while reducing costs and environmental impacts associated with conventional domestic wastewater treatment. More specifically, anaerobic membrane bioreactors (AnMBRs) hold promise to effectively treat wastewater at low temperatures with low energy and nutrient requirements, low sludge production, while having the benefit of generating methane-rich biogas suitable as an energy source and the potential to capture nutrients used to fertilize cropland. But, at low temperatures the microbial communities that control anaerobic digestion (AD) face biochemical obstacles. Elucidating the microbial community dynamics within AnMBRs with respect to seasonal temperatures will give insight on how to efficiently operate AnMBRs with the goal of energy-neutral wastewater treatment. DNA based tools such as advanced high-throughput sequencing was coupled with AnMBR process data to explicate the mechanism of methane production in the suspended biomass of an AnMBR from a mesophilic startup leading into psychrophilic conditions, and then returning to mesophilic temperatures.
116

Sistema de tratamento anaeróbio, aeróbio e anóxico para águas residuárias de suinocultura : remoção de matéria orgânica, de nutrientes e de coliformes /

Santos, Samantha Christine. January 2011 (has links)
Orientador: Roberto Alves de Oliveira / Banca: Carlos Augusto de Lemos Chernicharo / Banca: Edson Aparecido Abdul Nour / Resumo: Neste estudo avaliou-se o desempenho de processo anaeróbio, aeróbio e anóxico, utilizando-se um reator anaeróbio compartimentado (ABR de 360 L), com duas câmaras, um filtro aerado submerso (FAS de 160 L), preenchido com anéis de bambu e anéis de plástico de eletroduto corrugado e um reator de fluxo ascendente com manta de lodo (USB de 120 L) anóxico, instalados em série, para o tratamento de águas residuárias de suinocultura, com concentrações médias de sólidos suspensos totais (SST) de 10708 a 17048 mg L-1. Os tempos de detenção hidráulica (TDH) foram de 24 e 12 h no reator ABR; de 7,9 e 3,9 h e de 9,1 e 4,5 h no FAS preenchido com anéis de bambu e anéis de plástico de eletroduto corrugado, respectivamente; e de 7,8 e 3,9 h no reator USB anóxico. O FAS foi submetido a condições de aeração intermitente e contínua. As eficiências médias de remoção de DQOtotal foram de 94 a 99% no sistema de tratamento anaeróbio, aeróbio e anóxico, com carga orgânica volumétrica (COV) de 35,9 a 93,0 g DQOtotal (L d)-1 no reator ABR. As maiores eficiências médias de remoção foram de 99,99; 98; 99; 91; 88; 99 e 94% para os coliformes termotolerantes, DQOdiss, SST, NT, P-total, Cu e Zn, respectivamente, no sistema de tratamento anaeróbio, aeróbio e anóxico, obtendo-se valores mínimos de 1,1 x 103 NMP/100 mL para coliformes termotolerantes e 221 mg L-1 para DQOtotal. A porcentagem de CH4 no biogás do ABR variou de 76 a 84%; de N2 no reator USB anóxico chegou a 74%, com COV de 13,1 g DQOtotal (L d)-1 e TDH de 4 h. Os valores da atividade específica da microbiota do lodo das câmaras do ABR apresentaram diferenças, evidenciado a habilidade de separação das fases hidrolítica, acidogênica e metanogênica. A caracterização morfológica do biofilme do FAS, por meio de microscopia óptica, indicou alta diversidade morfológica, a qual pode estar associada a sistemas de tratamento biológico estáveis / Abstract: In this study it was evaluated the performance of the anaerobic, aerobic and anoxic process in an anaerobic baffled reactor (ABR of 360 L), with two chambers, a submerged aerated filter (SAF of 160 L), filled with bamboo rings and plastic rings, and an anoxic upflow sludge blanket reactor (USB of 120 L), installed in series, for swine wastewater treatment, with mean total suspended solid (TSS) concentration from 10708 to 17048 mg L-1. The hydraulic detention times (HDT) were 24 and 12 h in the ABR reactor; 7,9 e 3,9 h and 9,1 e 4,5 h in the SAF filled with bamboo rings and plastic rings, respectively; 7,8 and 3,9 h in the anoxic USB reactor. Conditions of intermittent and continuous aeration were applied at the SAF. The mean of CODtotal removal efficiencies ranged from 94 to 99% in the anaerobic, aerobic and anoxic treatment system under organic loading rate (OLR) of 35,9 to 93,0 g total COD (L d)-1 in the ABR reactor. The highest mean removal efficiencies were of 99,99; 98; 99; 91; 88; 99 e 94% for thermotolerant coliforms, dissCOD, TSS, TN, total-P, Cu and Zn, respectively, in the anaerobic, aerobic and anoxic treatment system, obtaining minimum values of 1,1 x 103 MPN/100 mL for thermotolerant coliforms and 221 mg L-1 for CODtotal. The CH4 percentage in the biogas ABR ranged from 76 to 84%; the N2 percentage in the anoxic USB reactor reached 74%, with COV of 13,1 g total COD (L d) -1 and HDT of 4 h. The observed values of microbial specific activity of the sludge in the ABR‟s chambers were significantly different, evidenced the ability to phase separation hydrolytic, acidogenic and methanogenic. The SAF biofilm morphology, through optical microscopy, indicated a high morphological diversity, which may be associated with stable biological treatment systems / Mestre
117

Utilização de lodo de efluente doméstico : efeitos na produtividade agrícola e em alguns aspectos ambientais /

Breda, Carlos Cesar. January 2003 (has links)
Orientador: Iraê Amaral Guerrini / Banca: Wanderley da Silva Paganini / Banca: Simone Damasceno / Banca: Roberto Lyra Villas Boas / Banca: Jorge de Lucas Junior / Resumo: O objetivo deste trabalho foi avaliar os efeitos da aplicação do lodo de esgoto proveniente de uma pequena estação de tratamento, localizada na Fazenda Experimental Lageado, Faculdade de Ciências Agronômicas-UNESP, Botucatu, SP, Brasil, na produtividade agrícola e características de plantas de milho, bem como seus impactos nas características do solo e na qualidade da água drenada para o freático. O delineamento experimental foi constituído por blocos ao acaso, com parcelas subdivididas no tempo (Ensaios), num total de 6 tratamentos, 4 blocos e 4 ensaios, sendo T1 (testemunha, sem fertilização); T2 (10t ha-1 de lodo seco); T3 (20t ha-1 de lodo seco); T4 (30t ha-1 de lodo seco); T5 (40t ha-1 de lodo seco) e T6 (adubação mineral). Os ensaios foram assim definidos: E1 (cultivo de verão instalado em 11/2000); E2 (cultivo de inverno instalado em 06/2001); E3 (segundo cultivo de verão instalado em 11/2001) e E4 (segundo cultivo de inverno instalado em 05/2002). Foi utilizado o milho como cultura teste. Os parâmetros avaliados no campo foram altura das plantas, diâmetro do colmo e número de folhas em três épocas diferentes, além da análise foliar. Após a colheita das espigas foram avaliados os componentes de produção: massa sem palha, comprimento, diâmetro e número de fileiras das espigas; massa da palha; diâmetro... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The objective of this study was to evaluate the effects of the use of sewage sludge, coming from a small treatment station, located in Lageado Experimental Farm, Agronomic Sciences College - UNESP, Botucatu, SP, Brazil, on productivity and characteristics of corn plants, as well as its impact on soil characteristics and quality of drained water. The experimental design constituted of randomized blocks, with split plots in time (Assays), with 6 treatments, 4 blocks and 4 assays. The treatments were T1 (control, without fertilization); T2 (10t ha-1 of dry sludge); T3 (20t ha-1 of dry sludge); T4 (30t ha-1 of dry sludge); T5 (40t ha-1 of dry sludge) and T6 (mineral fertilizer). The assays were defined as: E1 (first summer plantation, installed in 11/2000); E2 (first winter plantation, installed in 06/2001); E3 (second summer plantation, installed in 11/2001), and E4 (second winter plantation, installed in 05/2002). The parameters evaluated were height of plants, stem diameter and number of leaves, besides leaves chemical analysis. After harvesting of corn spikes, the production components were evaluated: spikes without straw; spike length, diameter and line number; straw weight; corncob diameter; number of spikes; weight of 1000 grains and grains for spike). Moreover, the corn productivity at 13% of... (Complete abstract click electronic access below) / Doutor
118

Tratamento de esgoto sanitario em reator anaerobio preenchido por casca de coco verde (Cocos nucifera) combinado com filtro de areia / Wastewater treatment through an anaeroboc filter filled up with coco nuts (cocos nucifera) combined with sand filter

Cruz, Luana Mattos de Oliveira, 1985- 13 August 2018 (has links)
Orientador: Ronaldo Stefanutti / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-13T07:16:42Z (GMT). No. of bitstreams: 1 Cruz_LuanaMattosdeOliveira_M.pdf: 2567384 bytes, checksum: 517d8663924f9e32a90ec5b64ae951c8 (MD5) Previous issue date: 2009 / Resumo: O desenvolvimento de sistemas de tratamento de esgoto, eficientes e adaptáveis às condições econômicas e estruturais de uma região seria uma opção para diminuir o problema da escassez de água, já que o efluente poderia ser reutilizado ou descartado nos corpos hídricos. Ainda, com o esgotamento sanitário, os problemas de saúde pública e do meio ambiente seriam menos agravantes. Frente a esta situação, o objetivo deste projeto foi estudar um sistema para o tratamento de esgoto doméstico de pequenas comunidades, composto por filtros anaeróbios seguidos por filtros de areia. Avaliou-se o desempenho de dois filtros anaeróbios com fluxos ascendentes e preenchidos com cascas de coco verde (Cocos nucifera) e de quatro filtros de areia com espessura de 0,75m. A partida dos reatores anaeróbios foi diferente pois um deles foi inoculado. O Tempo de Detenção Hidráulico (TDH) estudado variou de 12 horas até 3 horas. Nos quatro filtros de areia foram aplicadas diferentes taxas hidráulicas (300, 400, 500 e 600 Lm-2dia) com a finalidade de se encontrar a capacidade limite de aplicações diárias, mantendo seu efluente com qualidade compatível a legislações brasileiras, como o CONAMA 357. A avaliação dos reatores anaeróbios, do meio suporte e das taxas de aplicação nos filtros de areia foi realizada com a análise semanal do esgoto bruto, dos efluentes anaeróbios e dos efluentes dos filtros de areia quanto a parâmetros físicos, químicos e biológicos, conforme os procedimentos do Standard Methods for the Examination of Water and Wastewater. Os filtros anaeróbios mostraram-se estáveis frente a mudanças do TDH e a remoção de material orgânico foi em torno de 64% evidenciando que as cascas de coco verde podem ser utilizadas como meio suporte. Os filtros de areia puderam remover cerca de 80% da matéria orgânica e dos SST e, aproximadamente, 100% da turbidez. Além disso, apresentaram grande capacidade de aeração e nitrificação, gerando um efluente com 82% de concentração de nitrato em relação à concentração de nitrogênio total. Como os resultados foram satisfatórios, comprova-se que é possível a aplicação de maiores taxas hidráulicas nos leitos de areia. / Abstract: The development of efficient wastewater treatment systems, which are also adapted to the economic and structural conditions of a village, would be an option to decrease the lack of water problem since the effluent could be reused or discharged into receiving waters. Moreover, with wastewater system, health and environmental problems would be less frequent. For this reason, the aim of this investigation was to study a wastewater treatment system for small villages constituted by the combination of upflow anaerobic filters followed by sand filters. The performance of two upflow anaerobic reactors filled with coco nuts (Cocos nucifera) and four sand filters (0.75m deep) was evaluated. The anaerobic filters' staring up were different since one of them was inoculated. The hydraulic retention time (HRT), which was studied, varied from 12 to 3 hours. On the four sand filters, the anaerobic effluent was disposed in different frequencies of application (300, 400, 500 and 600 Lm-2dia-1) in order to estipulate the diary application limit capacity to keep the effluent quality according to Brazilian laws, like CONAMA 357. To evaluate the anaerobic reactors, the support and the frequency of application on the sand filters, weekly, sewage, anaerobic and final effluent were analyzed through physical, chemical and biological parameters, according to Standard Methods for the Examination of Water and Wastewater. Anaerobic reactors were stable even when HRT was modified and organic material removing was around 64% showing that the coco nuts can be used as a support. The sand filters could remove about 80% of organic matter and TSS and, approximately, 100% of turbidity. Besides, these filters showed a great capacity of aeration and nitrification producing an effluent with 82% of nitrate concentration from the total nitrogen concentration. As the results were satisfactory, it can be confirmed the possible higher frequencies of application in sand filters. / Mestrado / Saneamento e Ambiente / Mestre em Engenharia Civil
119

Biofotonica aplicada ao monitoramento microbiologico de efluentes sanitarios / Spontaneous light emission applied to microbiological wastewater monitoring

Santos, Samuel Ricardo dos, 1980- 02 May 2010 (has links)
Orientadores: Jose Euclides Stipp Paterniani, Cristiano de Mello Gallep / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola / Made available in DSpace on 2018-08-15T12:44:58Z (GMT). No. of bitstreams: 1 Santos_SamuelRicardodos_M.pdf: 4212906 bytes, checksum: ecb5c9bc690bf3b7b2b146796b9c61a1 (MD5) Previous issue date: 2010 / Resumo: As bactérias do grupo coliformes têm sido amplamente empregadas no monitoramento da qualidade da água, com o uso da Escherichia coli como microrganismo indicador de contaminação fecal. Os métodos atuais de detecção apresentam no mínimo 18 h para obtenção de resultados e em outros processos, que incluem testes bioquímicos, podem chegar até 48 h para análise conclusiva. A importância de uma rápida detecção de coliformes e Escherichia coli aplicada à qualidade e segurança da água torna-se óbvia e necessária. O uso de medidas da luz, presente em seres vivos, surge como metodologia promissora aplicada ao monitoramento microbiológico das águas, podendo gerar resultados em tempo reduzido de análise. No presente trabalho avaliou-se o potencial da técnica biofotônica aplicada ao monitoramento de efluentes sanitários em seu parâmetro microbiológico, através da detecção de emissão ultrafraca de luz em testes envolvendo coliformes. A metodologia baseou-se no acompanhamento dos padrões de emissão de luz em câmara escura com o uso de efluente doméstico, antes e após tratamento, incubados em meio nutritivo. O controle foi efetuado com o uso de cepa de Escherichia coli (ATCC 25922), incubada em meio nutritivo, tendo seu crescimento monitorado por emissão de luz. Os resultados com cepa e efluente doméstico incubados em substrato cromogênico apresentaram melhores correlações entre crescimento de microrganismos e emissão de luz, em contraste com ensaios efetuados com meio EC e meio nutritivo a base de lactose e lauril triptose. Os dados demonstram que o monitoramento microbiológico pode ser efetuado através da técnica biofotônica, com a identificação da emissão de luz por microrganismos com pelo menos três horas de análise em substrato cromogênico e pelo menos doze horas em meio EC e Presença/Ausência (P/A). / Abstract: The coliform bacteria have been widely used in water quality monitoring, using Escherichia coli as indicator of faecal contamination. Current standard methods for of coliforms and Escherichia coli detection take 18-h minimum and the complete testing process, including confirmatory biochemical tests, may require at least 48 hours. The importance of rapid detection of coliforms and Escherichia coli, regarding to the quality and safety of water, is obvious and necessary. The spontaneous light emission of living systems emerge as a promising methodology that applied to microbiological in monitoring water can lead to shortterm analysis. The present study evaluated the potential of biophoton measurements applied to wastewater monitoring by using ultraweak light emission in coliform tests. The procedure is based on photon-counting measurements inside a dark-chamber, of wastewater samples, before and after treatment, inoculated in nutrient medium. Strain of Escherichia coli (ATCC 25922) was used in control tests by monitoring the light emission in nutrient medium. The results for strain and wastewater incubated in chromogenic substrate show better correlation between microbial growth and light emission, in contrast to experiments with EC Broth and Presence/Absence nutritive medium. The data show that microbiological monitoring can be done by photon-counting with at least three hours in chromogenic substrate and at least twelve hours with EC and Presence/Absence Broth. / Mestrado / Agua e Solo / Mestre em Engenharia Agrícola
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Eletroflotação aplicada ao tratamento de esgoto sanitário / Electroflotation applied to the sewage treatment

Joel Alonso Palomino Romero 15 October 2009 (has links)
Este trabalho avaliou o desempenho de um reator piloto de eletroflotação, que utilizou placas de alumínio em arranjo monopolar em paralelo como eletrodos de sacrifício para o tratamento de esgoto sanitário. O processo foi auxiliado pela adição de cloreto de sódio para melhorar a condutividade do esgoto bruto. Preliminarmente, testaram-se em ensaios de eletroflotação em bancada, densidades de corrente entre 8 e 21 A m-2 e determinou-se que o melhor desempenho na diminuição da turbidez era obtido aplicando uma densidade de corrente próxima a 13,8 A m-2. Posteriormente foram conduzidos ensaios no reator piloto para determinar a vazão e a dosagem de cloreto de sódio. A partir destes foram determinadas as variáveis operacionais, que foram: densidade de corrente de 14,2 A m-2, vazão de 0,33 m3 h-1, dosagem de cloreto de sódio de 0,5 g L-1 e tempo de detenção hidráulica de 18,2 min. O reator piloto de eletroflotação foi testado com duas configurações de posição dos eletrodos: transversal e paralelo ao fluxo. O melhor desempenho do reator de eletroflotação foi obtido com o arranjo em paralelo ao fluxo; este permitiu aumentar a vazão para 0,5 m3 h-1 e diminuir a dosagem de cloreto de sódio para 0,25 g L-1. Amostras de esgoto bruto e esgoto eletroflotado obtidas do reator operando em ambas as configurações da posição dos eletrodos foram coletadas e submetidas a análises físico-químicas. Estas análises permitiram determinar a eficiência da remoção de: cor verdadeira em 82% e 86% para os arranjos das placas em transversal e paralelo ao fluxo respectivamente, da mesma forma a turbidez em 96% e 93%, sólidos totais em 90% e 97%, carbono orgânico total em 60% e 58%, nitrogênio amoniacal em 42% e 51%, demanda bioquímica de oxigênio em 91%, demanda química de oxigênio em 89% concentração de óleos e graxas em 100%, fósforo total em 99%, coliformes termotolerantes e E coli. em duas unidades log e aumento de oxigênio dissolvido em 400% e 366%. Uma análise de espectroscopia de emissão atômica também foi feita para determinar a concentração de espécies metálicas e não metálicas. Esta análise revelou que as espécies encontravam-se em concentrações baixas e em alguns casos abaixo do limite de detecção, mas após tratamento por eletroflotação estas concentrações também sofreram diminuição. O cálculo da massa teórica de alumínio desgastada nos ânodos foi calculada em 4 g m-3, a quantidade de lodo gerado foi de 0,16 m3 e os custos operacionais totais estimados em R$0,64 e R$0,38 kw h m-3 com o reator operando nas configurações de posição dos eletrodos transversal e paralelo respectivamente. Os valores dos parâmetros observados nas análises físico-químicas do esgoto eletroflotado se encontram dentro dos limites estipulados pela Resolução CONAMA No. 357 para o lançamento de efluentes e para águas de classe 3. A comparação das eficiências de remoção alcançadas pela eletroflotação com eficiências típicas de remoção dos principais poluentes nos esgotos domésticos, alcançadas por diversos métodos de tratamento permite afirmar que a eletroflotação é uma técnica eficiente no tratamento de esgoto sanitário e é economicamente viável, por isto deve ser considerada como uma alternativa aos métodos de tratamento convencionais. / This study assessed the performance of a domestic sewage treatment pilot unit of electroflotation, which used aluminum plates in a monopolar parallel arrange as sacrifice electrodes for sewage treatment. The process was aided by the addition of sodium chloride to improve the conductivity of the raw sewage. First, it was tested in lab-scale experiments, current densities between 8 and 21 A m-2. The best performance in the turbidity decrease was obtained by applying a current density close to 13.8 A m-2. Later experiments were conducted in the pilot reactor to determine the flow rate and dosage of sodium chloride. From these, the operational variables were determined, which were: current density of 14.2 A m-2, a flow rate of 0.33 m3 h-1, sodium chloride dosage of 0.5 g L-1 and hydraulic detention time of 18.2 min. The electroflotation pilot reactor was tested with two sets of electrode position: transverse and parallel to the flow. The best performance of the electroflotation reactor was achieved with the parallel arrangement; this allowed increase the flow to 0.5 m3 h-1 and reduce the amount of sodium chloride to 0.25 g L-1. In comparison to raw sewage, the treated effluent presents a decrease of 82% and 86% for the true color for the arrangement of plates in transverse and parallel respectively, just as a decrease in the turbidity by 96% and 93%, total solids by 90% and 97% total organic carbon by 60% and 58%, nitrogen by 42% and 51% biochemical oxygen demand at 91%, chemical oxygen demand at 89%, oils and greases concentration by 100 %, total phosphorus by 99%, fecal coliforms and E. coli. in two log units and increased dissolved oxygen in 400% and 366%. An atomic emission spectroscopy analysis was also done to determine the concentration of metal and non-metallic species. This analysis revealed that the species were in low concentrations and in some cases below the detection limit, but after electroflotation treatment these concentrations also decrease. The calculation of the theoretical mass of the worn aluminum anodes was estimated in 4 g m-3, the amount of sludge generated was 0.16 m3 and the total operating costs estimated at R$ 0.64 and R$ 0.38 kw h m-3 with the reactor operating in transverse and parallel settings of electrode position, respectively. The values of the parameters observed in the physicochemical analysis of electroflotated sewage are within the limits set by CONAMA Resolution No. 357 for the release of effluents and for Class 3 waters. Comparison of removal efficiencies achieved by electroflotation with typical removal efficiencies of major pollutants in domestic sewage, achieved by various treatment methods suggest that the electroflotation is an efficient technique for the treatment of sewage and is economically viable, therefore must be considered as an alternative to conventional treating methods.

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