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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.
11

Sistema de tratamento híbrido utilizado na remoção do corante reativo 5g de um efluente têxtil sintético

Santos, Bruna Souza dos 25 March 2015 (has links)
CNPQ; Fundação Araucária; FPTI / Nos últimos anos observou-se um crescimento das atividades industriais que provocou impactos significativos aos recursos naturais, e as preocupações com o ambiente em geral adquirem especial importância. Neste contexto, a indústria têxtil considerada uma importante atividade responsável por parte desse desenvolvimento, se caracteriza como geradora de efluente líquido amplamente poluidor devido ao grande volume de água necessária nesse processo produtivo. Levando em consideração os métodos convencionais e também as dificuldades no tratamento dos efluentes têxteis, o processo eletrolítico conhecido como eletrofloculação se constitui em uma possibilidade importante. Este processo envolve a desestabilização de poluentes emulsificados, ou em suspensão, em meio aquoso. Desta forma o objetivo deste trabalho foi implantar um sistema de tratamento híbrido utilizado na remoção do corante reativo azul 5G de um efluente têxtil sintético, através da eletrofloculação associada a adição de coagulante natural a base de Moringa oleífera Lam, a fim de potencializar o nível de tratamento que seria alcançado com as técnicas utilizadas isoladamente Inicialmente trabalhou-se exclusivamente com a eletrofloculação para a remoção do corante. As variáveis analisadas foram: ddp (diferença de potencial aplicado), tempo e pH. Considerando o intervalo de confiança de 95% somente o termo quadrático da ddp e o termo linear do pH se mostraram significativos. Os valores de remoção da cor para os ensaios variaram de 64,38 a 90,87% e para a validação uma remoção média de 89,01%, valores muito próximos do predito pelo modelo. Na sequência foi realizada a otimização das condições para obtenção do extrato aquoso de Moringa oleífera. Avaliou-se as seguintes condições: salinidade e tempo de extração. A concentração do coagulante obtido, em água turva sintética também foi um dos fatores estudados. As melhores condições para o extrato aquoso de Moringa oleífera foram: 20 segundos de agitação em ultrassom, e solução de 20% em cloreto de sódio. Para potencializar o nível de tratamento as duas técnicas (eletrofloculação e coagulante natural a base de Moringa oleífera), foram testadas inicialmente em batelada e na sequência em fluxo contínuo. Os ensaios em batelada foram divididos em duas partes, o primeiro DCCR avaliou a intensidade de corrente elétrica (I), o tempo da eletrofloculação e a concentração do coagulante (MO), o qual obteve uma remoção de cor de 77,27% a 91,33%. Porém, nenhum termo foi significativo, mas o tempo apresentou menor efeito. Sendo assim, um novo planejamento foi realizado, o segundo DCCR, fixando o tempo na condição mínima, além das faixas de I e MO que também foram reduzidas. Obteve-se então uma remoção da cor para os ensaios de 13,45 a 80,8%, e para a validação uma remoção média de 86,56%. Para o módulo contínuo, as variáveis estudadas foram a intensidade de corrente elétrica (I), concentração do coagulante (MO) e tempo de retenção hidráulica (TRH). Dentre elas somente o TRH não se mostrou significativo. A remoção da cor variou de 8,46% a 90,25%. Nestes ensaios também foram realizados as análises das concentrações de Ferro Residual, e os valores obtidos variaram de 3,70 mg.L-1 a 9,03 mg.L-1, ficaram abaixo do valor máximo permissível pela Legislação (15 mg.L-1). Para maximizar a remoção da cor e minimizar a concentração de ferro residual, a função desejabilidade do software STATISTICA™ foi utilizada e nessas condições somente a I e a MO foram significativas. A partir da validação foi possível observar a tendência de remoção prevista pelo modelo. Obteve-se uma remoção da cor para a validação de 71,38% e uma concentração média de ferro residual de 5,2237 mg. L-1, porém, com um erro distante do esperado (32,85%). / In recent years there has been a growth of industrial activities that caused significant impacts to natural resources, and concerns about the environment in general are of particular importance. In this context, the textile industry considered an important activity responsible for part of that development is characterized as liquid effluent generating widely polluter due to the large volume of water needed in this production process. Taking into account the conventional methods and also the difficulties in treating textile effluents, the electrolytic process known as eletrofloculation constitutes an important possibility. This process involves the destabilization of the emulsified pollutants, or suspension in aqueous medium. Thus the aim of this study was to implement a hybrid treatment system used in removing the blue reactive dye 5G of a synthetic textile effluent by eletrofloculation associated with adding natural coagulant the basis of Moringa Oleifera Lam, in order to enhance the level treatment would be achieved with the techniques used alone initially worked up exclusively with eletrofloculation to remove the dye. The variables analyzed were: ddp (potential difference applied), time and pH. Whereas the 95% confidence interval only the quadratic term of the linear term DDP and pH were significant. The removal of color values for the tests ranged from 64.38 to 90.87% and validating an average removal of 89.01%, very close values predicted by the model. Following was carried out to optimize the conditions for obtaining the aqueous extract of Moringa oleifera. Salinity and extraction time: The following conditions were evaluated. The concentration of the coagulant obtained in synthetic turbid water was also one of the factors studied. The best conditions for the aqueous extract of Moringa oleifera were 20 seconds of ultrasound in agitation, and solution of 20% sodium chloride. To enhance the level of treatment the two techniques (eletrofloculation and natural coagulant Moringa oleifera the base), were initially tested in batch and following streaming. The batch tests were divided into two parts, the first CCRD evaluated the intensity of electric current (I), the time eletrofloculation and concentration of the coagulant (MO), which obtained a color removal of 91 to 77.27% 33%. But no term was significant, but time showed less effect. Thus, a new planning was done, the second CCRD, setting the time at a minimum, in addition to the R and MO tracks that were also reduced. There was thus obtained a removal color for testing 13.45 to 80.8%, and validating an average removal of 86.56%. For the continuous form, the variables studied were the intensity of electric current (I), the coagulant concentration (MO) and hydraulic retention time (HRT). Among them only HRT was not significant. The color removal ranged from 8.46 % to 90.25%. In these assays were also performed the analysis of the residual iron concentrations, and the values obtained ranged from 3.70 mg L- 1 to 9.03 mg.L-1, were below the maximum value allowable by law (15 mg.L-1). To maximize the removal of color and minimize the residual concentration of iron, the desirability function STATISTICA ™ software was used and under these conditions only I and MO were significant. From the validation was observed removing trend predicted by the model. Obtained was a color removal for the validation of 71.38 % and an average concentration of 5.2237 mg.L-1 of residual iron, but with a far from the expected error (32.85%).
12

Toxicity characteristic leaching procedure analysis of dye containing sludges

Nelson, John D. 06 October 2009 (has links)
The ability to leach dyestuffs contained in municipal sludge using the Toxicity Characteristic Leaching Procedure (TCLP) was investigated. In addition to the dyestuffs, metals and other organic compounds which also leached were identified. Only small amounts of color were detected in the TCLP extracts; the mean ADMI color values for undigested and aerobically digested sludges were 240 and 156 ADMI color units respectively. Concentrations of individual dyes that may have leached into the TCLP extracts were below detection limits. The reactive vinyl sulfone aniline moiety, which is released as a reduction product from the Remazol dyes used in the cellulosic textile dyeing industry, was found in the leachate from the sludge not treated by extended aerobic digestion. In the leachate from the sludge treated by extended aerobic digestion the reactive vinyl sulfone aniline reduction product was not found, suggesting that this compound was destroyed or rendered immobile by aerobic digestion. Metals leached from the sludge in trace amounts from 0.05 μg/L up to 1 mg/L. Several organic compounds detected in influent wastewater and in leachate from undigested sludge were not found in the leachate from digested sludge. / Master of Science
13

Assessment of public awareness of septic systems in rural Benton County

Gillett, Christopher S. 29 July 1998 (has links)
Graduation date: 1999
14

Micro e ultrafiltração como pós-tratamento para reúso de efluentes de abatedouro e frigorífico de suínos

Fappi, Devanir André 26 March 2015 (has links)
Fundação Araucária; CAPES / As indústrias alimentícias utilizam considerável volume de água para suprir a demanda de processos. Devido a isso, observa-se um grande volume gerado de efluentes que necessitam ser tratados para garantir o destino final adequado. Tendo em vista a crescente escassez de água, procedimentos de racionalização do uso da água e o reúso de efluentes tratados surgem como soluções para estes problemas. A aplicação de processos de separação por membranas no tratamento de efluentes da indústria alimentícia para reúso apresenta-se como um processo de tratamento avançado apropriado. Deste modo, o objetivo deste estudo foi avaliar a utilização dos processos de separação por membranas como tratamento avançado de águas residuárias agroindustriais provindas de um abatedouro e frigorífico de suínos, da região oeste do Paraná, visando à possibilidade de reúso destes efluentes. Para isso, foi necessário: realizar a caracterização físico-química dos efluentes agroindustriais; avaliar o emprego de microfiltração, ultrafiltração, e microfiltração seguida de ultrafiltração em diferentes condições operacionais de pressão aplicada à membrana, e avaliar a qualidade do efluente obtido pelos processos de separação com membranas, considerando o atendimento das exigências técnicas, legais e sanitárias para diferentes usos industriais. Os resultados mostraram que os processos de separação por membranas apresentaram, de uma maneira geral, uma sensível melhora na qualidade do efluente final quando comparados com o atual sistema de pós-tratamento empregado pela indústria (flotador físico-químico), que promove eficiências de remoção nas faixas oscilantes de 3% a 29%, 44% a 70%, 40% a 46% e 50% a 58,5%, aproximadamente, para os parâmetros sólidos totais voláteis, turbidez, nitrogênio amoniacal e DQO, respectivamente. A microfiltração apresentou as seguintes faixas de eficiência de remoção, aproximadas: sólidos totais voláteis (51% - 64%), turbidez (83% - 99%), nitrogênio amoniacal (21% - 24%) e DQO (64% - 72%). A ultrafiltração apresentou as seguintes faixas de eficiência de remoção, aproximadas: sólidos totais voláteis (23% - 51%), turbidez (87% - 99%), nitrogênio amoniacal (54% - 69%) e DQO (77% - 85%). A realização do ensaio de microfiltração seguido de ultrafiltração nas melhores condições experimentais investigadas obteve resultados satisfatórios na remoção de aproximadamente 97% para a turbidez, 17% para os sólidos totais voláteis, 67% para a DQO, 38% para o nitrogênio amoniacal, 96% a 99,95% para os coliformes termotolerantes e 93 a 99,69% para os coliformes termorresistentes. Com o aumento da pressão para a microfiltração e ultrafiltração foi obtido maior fluxo permeado e melhor qualidade do efluente final. Embora os efluentes tenham proporcionado distintos valores de fluxo permeado, foram obtidas curvas de desempenho bastante semelhantes, caracterizando-se por uma queda do fluxo permeado nos primeiros minutos de filtração, seguido de um período onde ocorre declínio gradual, com uma tendência ao equilíbrio. De acordo com os requisitos físico-químicos e microbiológicos mínimos exigidos para o reúso de efluentes tratados, a microfiltração e a ultrafiltração atenderam alguns dos parâmetros monitorados, alcançando a qualidade exigida para o reúso em torres de resfriamento, lavagem de pisos, irrigação de áreas verdes, lavagem de veículos, proteção contra incêndio e descarga sanitária. / The food industry uses large volumes of water to meet the demand processes. Because of this, there is a large volume of generated waste that need to be addressed to ensure proper final destination. In view of the growing scarcity of water, the use rationalization of procedures of the water and the reuse of treated effluent arise as solutions to these problems. Application of separation processes by membranes in the treatment of wastewater for reuse food industry presents itself as an appropriate advanced treatment process. Thus, the aim of this study was to evaluate the use of membrane separation processes as advanced treatment of agroindustrial wastewater stemmed from a swine slaughterhouse, the western region of Paraná, aiming at the possibility of recycling these effluents. For this it was necessary: to define the physical-chemical characterization of the agro-industrial effluents; evaluate the use of microfiltration, ultrafiltration, microfiltration and ultrafiltration then under different conditions of pressure applied to the membrane, and evaluate the quality of the effluent obtained by separation processes with membranes, considering the care of the technical, legal and health requirements for different uses industrial. The results showed that membrane separation processes presented in a general way a considerable improvement in final effluent quality compared with the current tertiary treatment system used by the industry (physicochemical flotation) which promotes removal efficiencies in oscillating ranges from 3% to 29%, 44% to 70%, 40% to 46%, 50% to 58.5%, approximately, for the parameters: total volatile solids, turbidity, ammonia nitrogen and COD, respectively. Microfiltration had the following removal efficiency ranges, approximate: total volatile solids (51% - 64%), turbidity (83% - 99%), ammonia nitrogen (21% - 24%) and COD (64% - 72%). Ultrafiltration showed the following removal efficiency ranges, approximate: total volatile solids (23% - 51%), turbidity (87% - 99%), ammonia nitrogen (54% - 69%) and COD (77% - 85%). The completion of the test microfiltration followed by ultrafiltration under the best experimental conditions investigated achieved satisfactory results in the removal of approximately 97% for the turbidity, 17% total volatile solids, 67% for COD, 38% for ammonia nitrogen, 96% to 99.95% for thermotolerant and 93 to 99.69% for the heat-resistant coliforms coliforms. With increasing pressure to microfiltration and ultrafiltration permeate flux was increased and better quality of the final effluent. Although the effluents have provided separate permeate flow rates, very similar performance curves were obtained, characterized by a drop in permeate flux during the first minute filtration followed by a period where there is a gradual decline, with a tendency toward equilibrium. According to the physicochemical requirements and minimum microbiological required for the reuse of treated wastewater, microfiltration and ultrafiltration attended some of the monitored parameters, achieving the required quality for reuse in cooling towers, floor washing, irrigation of green areas , washing vehicles, fire protection and sanitary discharge.
15

Caracterização do esgoto sanitário e lodo proveniente de reator anaeróbio e de lagoas de estabilização para avaliação da eficiência na remoção de contaminantes

Lopes, Thiara Reis 30 March 2015 (has links)
CAPES / As Estações de Tratamento de Esgoto (ETEs), são utilizadas com o objetivo de simular os fenômenos naturais de degradação em condições controladas para promover o tratamento dos esgotos, durante este processo, ocorre à produção de um subproduto denominado lodo de esgoto, constituído basicamente por uma mistura de matéria orgânica e inorgânica, que durante o processo de tratamento do esgoto permanece acumulada no sistema. As características do esgoto e do lodo estão relacionadas com as atividades antrópicas, condições climáticas, avanços tecnológicos que também contribuem com a inserção de compostos de difícil degradação, raramente tratados e removidos por processos convencionais. O objetivo desta pesquisa foi avaliar as características do esgoto e do lodo gerado em dois sistemas convencionais aplicados no tratamento do esgoto, estimar a eficiência dos sistemas e indicar o melhor potencial uso agrícola do lodo produzido. Para isso, foram determinados no afluente e efluente dos sistemas de tratamento biológico os parâmetros físico-químicos (pH, temperatura, oxigênio dissolvido, sólidos totais, sólidos totais fixos, sólidos totais voláteis, sólidos sedimentáveis, Demanda Química de Oxigênio (DQO), nitrogênio amoniacal). No lodo foram determinados parâmetros físico-químicos (pH, fósforo, potássio, íons metálicos, sólidos totais, sólidos totais fixos, sólidos totais voláteis, umidade, matéria orgânica e carbono orgânico total) e biológicos (coliformes termotolerantes, E. coli, Salmonella sp.). Os isolados de E. coli e Salmonella sp. foram submetidos a testes de susceptibilidade a agentes antimicrobianos. Os resultados indicaram que os esgotos avaliados apresentaram pH próximos à neutralidade e temperaturas ótimas para as atividades bacterianas. Ao comparar os sistemas de tratamento, a ETE operada com lagoas foi mais eficiente na conversão de nitrogênio amoniacal, sólidos e menor eficiência na redução da DQO. Todos os parâmetros avaliados no esgoto, apresentaram concentrações inferiores aos limites estabelecidos na legislação, exceto o nitrogênio amoniacal, e em determinadas amostragens a DQO e o OD. Em relação ao lodo, este apresentou pH próximos à neutralidade, a concentração de fósforo, potássio e matéria orgânica no lodo do sistema operado com RALF foi superior a do sistema operado com lagoas. Às concentrações dos íons metálicos no lodo do RALF foram superiores às do lodo do leito de secagem, nas lagoas essas concentrações reduziram durante o processo de tratamento. Ao comparar as ETEs, às concentrações dos íons metálicos foram maiores no lodo do RALF, exceto Mn e Ni, e a concentração de Fe foi semelhante entre os sistemas. No lodo do RALF, do leito de secagem e das lagoas foram detectadas colônias de Salmonella sp. resistentes à amoxicilina (10µg), tetraciclina (30µg) e cefalotina (30µg). As colônias de E. coli, foram sensíveis apenas à gentamicina. Este estudo possibilitou avaliar a eficiência destes sistemas convencionais de tratamento de esgotos, os resultados evidenciam a necessidade de utilizar métodos adequados de tratamento que possibilitem a remoção desses antibióticos e inativação dos microrganismos patogênicos, pois indicam um potencial risco das ETEs na dispersão desses no ambiente. / The Wastewater Treatment Plants (WWTPs) are used in order to simulate the natural degradation phenomena using controlled conditions to promote sewage treatment, a byproduct called sewage sludge is produced during this process, this is one blend of organic and inorganic material, it was accumulated in the system during the sewage treatment process. The sewage and sludge characteristics are related to human activities, weather conditions. Technological advances can contribute to the insertion of some compounds that are difficult to degrade, rarely treated and removed by conventional methods. This research aims to evaluate the sewage and sludge characteristics, estimating the efficiency of two conventional treatment systems and verify the agricultural potential use of sludge produced. For this, were determined in the influent and effluent of the biological systems of wastewater treatment some physico-chemical parameters (pH, temperature, Dissolved Oxygen (DO), total solids, total fixed solids, total volatile solids, settleable solids, chemistry oxygen demand (COD), ammonia nitrogen). In the sludge were determined physico-chemical parameters (pH, total solids, total fixed solids, total volatile solids, total phosphorus, total K, metals, humidity, organic matter and total organic carbon) and biological (CTT, E. coli, Salmonella sp.). The isolates of E. coli and Salmonella sp. were tested to antimicrobial agents. The results indicated the pH in sewage was near to neutrality and optimum temperatures for bacterial activities. By comparing the treatment systems, the WWTP operated with ponds was more efficient in ammonia nitrogen conversion, removing solids and less efficient in reducing COD. All results were below the limits established by law, except ammonia nitrogen and in some samples the DO and COD. The pH in sludge was slightly acid and near neutrality. The concentration of phosphorus, potassium and organic material in the sludge collected in the system operated with RALF exceeded the system operated with ponds. The concentrations of metal ions in sludge of RALF were higher than those of the sludge drying bed, in ponds the concentrations decreased during the treatment process, to compare the WWTPs, the concentrations of metal ions were higher in RALF sludge, except Mn and Ni, and the Fe concentration was similar. In the sludge of RALF, in the drying bed and ponds were detected Salmonella sp. resistant to amoxicillin (10µg), tetracycline (30µg) and cephalothin (30µg). The E. coli were susceptible only to gentamicin. This study evaluated the efficiency of these conventional systems applied in sewage treatment, the results suggest the need to use appropriate methods of treatment to removal of these antibiotics and inactivation the pathogenic microorganisms, this indicate a potential hazard of these WWTPs in the dispersion of the environment.
16

Otimização da remoção da matéria carbonácea e nitrogenada do esgoto sanitário por reator anaeróbio e aeróbio de leito fixo / Optimizing the removal of carbonaceous and nitrogenous matter of sanitary wastewater by anaerobic-aerobic combined fixed bed system

Belini, Aldria Diana 29 February 2016 (has links)
CAPES; CNPq; Sanepar; Fundação Araucária / O aumento da população agrava a qualidade dos corpos receptores existentes, devido a concentração dos despejos de esgotos sanitários com elevadas cargas carbonáceas e nitrogenadas. Existem inúmeras operações de tratamento, porém, a aplicação dos processos biológicos, na maioria dos casos é a alternativa mais econômica. Logo, este trabalho tem por objetivo, otimizar a remoção da matéria carbonácea e nitrogenada de esgotos sanitário por sistema combinado composto de reator anaeróbio e aeróbio de leito fixo. O sistema foi composto de reatores anaeróbio e aeróbio de leito fixo, com escoamento ascendente e fluxo continuo, base retangular e volume útil de 19,8 L e 19,3 L respectivamente, mais um dispositivo de separação de sólidos líquidos com volume útil de 7,3 L (TDH de 8h em cada reator) e 9,8 L (TDH de 6h em cada reator). O meio suporte para imobilização da biomassa era constituído de anéis corrugados de Policloreto de Polivinila (PVC). O Sistema foi operado em 6 etapas distintas em que foi variado a taxa de recirculação (etapa 1 50%, etapa 2 100% e etapa 3 150%) e vazão de aeração (etapa 4 10 L.min-1, etapa 5 5 L.min-1 e etapa 6 2,5 L.min-1). Para a avaliação do sistema, determinou-se os seguintes parâmetros físico-químicos: temperatura do líquido (TL), pH, alcalinidade total (AT), alcalinidade a bicarbonato (AB), ácidos voláteis (AV), oxigênio dissolvido (OD), demanda química de oxigênio (DQO) nitrogênio total kjeldahl (N-NTK), nitrogênio amoniacal (N-amoniacal), nitrito (N-NO2-), nitrato (N-NO3-) e fósforo total (P). A avaliação do comportamento hidrodinâmico foi realizada pela técnica de estímulo-resposta tipo pulso com injeção do corante Eosina Y. Os resultados obtidos nas três primeiras etapas com influência da variação da taxa de recirculação (50%, 100 % e 150 %), apresentaram remoções da concentração de matéria orgânica em termos de DQO(amostras brutas) superiores a 97 %, em relação a concentração de nitrogênio, a remoção de N-NTK ficou superior a 95 %; foi possível concluir que quanto maior a taxa de recirculação maior é a eficiência de remoção de nitrogênio e menores são os valores de nitrito e nitrato, entretanto cabe ressaltar que o aumento da taxa de recirculação provoca o aumento da concentração de OD no reator anaeróbio o que pode provocar o desequilíbrio do processo. Ao observar a influência da variação da vazão de aeração com taxa de recirculação constante de 100 %, as remoções de matéria orgânica apresentaram remoção de DQO (amostras brutas) superiores 98 a % enquanto a remoção de nitrogênio caiu conforme a diminuição da vazão de aeração (Qa) com eficiências de remoção de N-NTK superiores a 96% (Qa = 10 L.min-1), 90 % (Qa = 5 L.min-1) e 45 % (Qa = 2,5 L.min-1). E em relação a variação do TDH, na remoção de matéria orgânica, obteve valores de remoção superiores de DQOamostras brutas a 98 % (TDH de 8h em cada reator) e 99 % (TDH de 6h em cada reator) enquanto que para remoção de nitrogênio as eficiências foram superiores a 96% para ambos os TDH testados o que evidência que o sistema combinado apresentou boa capacidade de amortecer a variação de cargas hidráulicas como orgânicas. / The increase in population worsens the quality of existing receiving bodies, because the concentration of sewage dumps with high organic and nitrogen loads. There are numerous processing operations, however, the application of biological processes, in most cases is the most economical alternative. Thus, this study aims to optimize the removal of carbonaceous and nitrogenous matter sanitary sewer system consists of a combined anaerobic and aerobic fixed bed reactor. The system was composed of anaerobic and aerobic fixed-bed reactors, with upward flow and continuous flow, rectangular base and useful volume of 19.8 L and 19.3 L, respectively, plus a solid liquid separation device with a volume of 7 3 L (HDT 8 h in each reactor) and 9.8 L (HDT 6 h in each reactor). The medium support for biomass immobilization consisted of corrugated rings Polyvinyl Polyvinyl (PVC). The system was operated in six different stages in which was varied the recirculation rate (50% step 1, 100% step 2 and step 3 150%) and flow aeration (step 4 10 L.min-1, Step 5 5 L .min-1 and step 6 2.5 L.min-1). For the evaluation system, it was determined the following physicochemical parameters: liquid temperature (TL), pH, total alkalinity (AT), bicarbonate alkalinity (AB), volatile acids (AV), dissolved oxygen (DO), chemical oxygen demand (COD) Total kjeldahl nitrogen (N-TKN), ammonia (N-ammonia), nitrite (N-NO2-), nitrate (N-NO3-) and phosphorus (P). The hydrodynamic behavior evaluation was performed by pulse type stimulus-response technique of injection of the dye Eosin Y. The results obtained in the first three steps with recirculation rate influence of variation (50%, 100% and 150%) showed removal concentration of organic matter in terms of COD (raw samples) greater than 97%, for nitrogen concentrations, the removal of N-TKN was greater than 95%; it was concluded that the higher the recirculation rate is nitrogen removal efficiency and lower the nitrite values and nitrate, however it is worth noting that increasing the recirculation rate causes an increase of OD concentration in the anaerobic reactor which may cause the imbalance of the process. To observe the influence of variation in the flow aeration with constant recirculation rate of 100%, the removal of organic matter showed a COD(raw samples) removal higher than 98% while the nitrogen removal fell as the reduction of aeration flow ( Qa) with N-TKN removal efficiencies exceeding 96% (Qa = 10 L.min-1), 90% (Qa = 5 L.min-1) and 45% (Qa = 2.5 L.min-1). And regarding the variation of TDH, in the removal of organic matter, obtained higher removal values DQO(raw samples) 98% (HDT of 8 hours in each reactor) and 99% (HDT of 6 hours in each reactor) while for nitrogen removal efficiencies were higher than 96% for both tested HDT which shows that the combined system showed a good ability to cushion the variation of hydraulic and organic fillers.
17

The perceptions of the residents of Polokwane on alternative faecal sludge management

Chuma, Mathudi January 2017 (has links)
Thesis (MPA.) -- University of Limpopo, 2017 / The World Health Organisation (WHO) and World Bank (WB) state that worldwide access to sanitation has improved with countries in the north having 100% access to sanitation. However, only 64% of the world's population has access to improved sanitation. Sub-Saharan Africa has a noticeable improvement with South Africa improving from 73% in 2010 to 74% in 2014. They further estimate that $260 billion is lost globally each year due to lack of adequate water supply and sanitation. Universal access to water and sanitation would result in an estimated $32 billion in economic benefits per year globally from reductions in health care costs and increased productivity from reduced illness. Sub-Saharan Africa loses an estimated 4.3% ($US694 billion) of its Gross Domestic Product (GDP) each year due to lack of adequate water supply and sanitation. Furthermore, the UNDP (2015) indicates that sanitation is one of the Millennium Development Goals (MDG), however many regions are performing poorly in attaining their declared sanitation targets. South African has not reached its target but it is maintaining its commitment to the provision of sanitation as a basic human right. However, it has left the responsibility to local government to work out how this should be done with no legislation. Currently there is no policy on sanitation and municipalities only develop by-laws that serve as guidelines in managing waste and providing the service. The available literature on this subject speaks very little about the knowledge and understanding that the communities have with regard to faecal sludge management and no study at all deals with the perceptions of people on this issue, particularly around Polokwane Municipality. It is for these reasons that the study was aimed at investigating the perceptions of Polokwane residents regarding alternative faecal sludge management. Methodologically the study used qualitative research approach where in face-to-face interviews and focus group interviews were conducted around Polokwane Municipality. Among the participants interviewed were Ward Councillors, Community Development Workers, Ward Committees and Traditional Authorities. These stakeholders were intentionally chosen as they are at the coalface of service delivery on a daily basis and they are part of the forums that interact with the Municipality on basic services and other related community matters. Data for this study were analysed using thematic data analysis approach. vi  The findings of this study suggest that the “concerned residents” under Polokwane Municipality see themselves being victims and vulnerable to controllable health threats. In addition, the study discovered that the majority of participants were aware of the delegated sewage maintenance duties on the Polokwane Municipality. This study findings further indicated that there is a growing concern among municipal authorities and communities‟ especially in Africa and South Africa in particular, to improve the inadequate faecal management. The objectives of the study were among others to determine the perceptions and awareness of the Polokwane Local Municipality residents regarding alternative faecal sludge management methods. Indeed, it has been discovered that some of the residents are aware of various management methods but expect authority to develop policies and improve the inadequate methods that are currently used in managing faecal sludge. The study among others discovered that this study should be used as a point of reference for municipal projects administration, i.e. for the development of Integrated Development Plan (IDP) on the water and sanitation and faecal sludge management in future. The Ministry of environmental health and management at Polokwane Local Municipality should organise solid and integrated awareness with the community to ensure a healthy environment for all. The study further realised that there is a need to equip most of residents in Polokwane Local Municipality with knowledge on how best man can improve environmental health, as well as how worse can a person destroy the environment. It should be an important task for the Polokwane Local Municipality to ensure that residents understand the faecal sludge management enterprise developments in the area to reduce the incompleteness of the perceptions among the residents. Various faecal sludge methods should be adopted and encouraged among the Polokwane Local Municipality residents in order to promote the preference for the sanitation methods. Key words: Sanitation, Faecal sludge, Faeces, Health hazards and Sub-Saharan Africa
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Sewage and the ecology of the St. Lawrence River

DeBruyn, Adrian M. H. January 2001 (has links)
No description available.
19

Urban stormwater management in Vietnam

Le Phu Vo. January 2000 (has links) (PDF)
Bibliography: leaves 84-91. Examines the current status of urban stormwater and water resources management in Vietnam
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Recharge characteristics of an effluent dominated stream near Tucson, Arizona

Lacher, Laurel Jane,1964- January 1996 (has links)
Almost 90% of the treated sewage effluent processed by the two treatment plants serving the greater Tucson area is available for passive recharge through the Santa Cruz River streambed north of Tucson. In the absence of any major disturbance of the effluent channel, the recharge capacity of the streambed materials decreases over time as microbial activity, and possibly suspended sediments settling out of solution, act to clog the surficial sediments under the effluent stream. Effluent stream transmission-loss measurements made over the period from November 1994 to August 1995 provided data used to determine the average vertical hydraulic conductivity of the low-flow channel in the study reach through simulations using the computer model known as KINEROS2. Saturated hydraulic conductivity (KSAT) served as the calibration parameter in the model. The appropriate KSAT value was chosen for each set of field data by matching the observed and simulated downstream hydrographs for the study reach. KSAT values were corrected for viscosity changes resulting from changing average daily surface water temperatures over the study period. Saturated hydraulic conductivity values for the effluent stream channel ranged from a maximum of 37 mm/hr in January, 1995, following several major winter storms, to a minimum of 11 mm/hr in August, 1995, after a nearly six-month interstorm period. The saturated hydraulic conductivity values decay exponentially with time after the last major winter storm. The mathematical model describing this decay may be used to estimate effluent recharge rates under similar future meteorological and climatological conditions.

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