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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.
1

Biologically enhanced ion exchange of ammonium ion using clinoptilolite

McVeigh, Ryan January 1999 (has links)
No description available.
2

Treatment of Industrial Wastewater by Gravel-type Constructed Wetlands

Lin, Hsin-Yi 07 September 2000 (has links)
In this study, we discussed the treatment efficiencies of different types of industrial wastewaters by several lab-scale constructed wetlands. The purpose this study is to decrease certain pollutants in the effluents from the industrial wastewaters treatment plants investivate the feasibility of water reuse and recovering. We divided the experiment into two stages, and three types of industry wastewaters ,including paper, steel and refiring, are in this study. In the first stage, the treatment efficiencies of controlling the flow rate at 6 mL/min higher that those controlling at 4 mL/min. However, sinece the amounts of phosphur were smalls in the industrial weatewaters, the removal efficiencies are not high enough. Thus, we added sewage and phousphate into the wastewaters in second stage of experiments with the best ratio of N : P of 4 : 1. The performance work of these two stage experiments did help to clean the nutrient of nitrogenous in the industrial wastewater, especially the refining industry comparing to the other two types of industries.
3

Estudo da remoção de nitrogênio via nitrito e via nitrato em sistemas de lodo ativado alimentados por despejo com elevada concentração de fenol. / Study of nitrogen removal via nitrite and via nitrate in activated sludge systems fed by wastewater with high phenol concentration.

Aun, Mariana Vivolo 11 October 2007 (has links)
Efluentes com grandes concentrações de fenol e nitrogênio amoniacal apresentam grande potencial poluidor ao meio ambiente. Exemplo deste tipo de despejo é o da unidade de coqueria da indústria siderúrgica que apresenta em termos quantitativos os fenóis como os principais constituintes orgânicos. Constituintes inorgânicos também estão presentes neste tipo de despejo e são principalmente cianeto, tiocianato, sulfato e nitrogênio amoniacal, sendo que a concentração deste último pode atingir níveis de centenas de miligramas por litro. No Estado de São Paulo, para atendimento às legislações em vigor - Decreto Estadual 8468/76 e Resolução CONAMA 357/05 - em termos de nitrogênio amoniacal e fenóis, as fontes poluidoras devem atender aos limites de emissão de 20 mg N/L para nitrogênio amoniacal total e 0,5 mg C6H5OH/L para índice de fenóis, e além disso, devem atender a classificação do corpo d\'água. Após resultados bem sucedidos de pesquisas realizadas anteriormente no Departamento de Engenharia Hidráulica e Sanitária da EPUSP objetivando remoção de compostos fenólicos e nitrogênio amoniacal, presentes em uma água residuária sintética de coqueria, através de nitrificação/desnitrificação do afluente em sistemas de lodo ativado, idealizou-se a presente pesquisa objetivando promover a nitrificação/desnitrificação de um despejo similar contendo altas concentrações de fenol (1000 mg/L) e nitrogênio amoniacal (500 a 1000 mgN/L) em sistema piloto de lodo ativado de lodo único, com duas concepções distintas: parcial (\"P\") a nitrito (ou \"nitritação/desnitritação\") em um primeiro caso, somente com fonte interna de carbono para a desnitrificação, e total (\"T\") num segundo caso, com fontes interna e externa de carbono. Além disso, também foi objetivo comparar os resultados obtidos do sistema piloto \"P\" com um sistema em bateladas seqüenciais operado paralelamente para remoção de nitrogênio via nitrito. A pesquisa permitiu concluir que o sistema contínuo, em virtude de seu regime operacional, não foi eficiente para remoção de nitrogênio via nitrito por não favorecer a manutenção de amônia livre na fase aeróbia em concentrações inibitórias aos microrganismos oxidadores de nitrito, já que segundo os resultados satisfatórios do sistema em bateladas seqüenciais, a existência de amônia livre e o pH se mostraram os principais parâmetros que regem o acúmulo de nitrito no reator. Apesar disso, o sistema apresentou resultados satisfatórios quanto à desnitrificação com fenol como fonte de carbono sendo que, durante toda a operação do sistema, o efluente final apresentou concentrações de fenol desprezíveis. Resumindo, o sistema contínuo só se mostrou adequado para remoção de nitrogênio via nitrato, ao passo que o sistema em batelada favoreceu a remoção via nitrito. Quanto ao sistema \"T\", que visava nitrificação/desnitrificação completa com fontes interna e externa de carbono, os resultados permitiram concluir que, apesar do etanol ser utilizado com eficiência pelas bactérias heterotróficas para promover a desnitrificação, seu uso como fonte externa de carbono não foi adequado em sistema de lodo único. Isto porque os microrganismos deixaram de utilizar o fenol na desnitrificação passando a utilizar somente o etanol, provocando acúmulo de fenol e desequilíbrio do sistema. Sendo assim, concluiu-se que o uso de etanol como fonte externa de carbono para a desnitrificação só seria recomendável em reator anóxico em separado, ou seja, em sistema de dois lodos e não de lodo único, como o da presente pesquisa. / Wastewaters containing high phenol and ammonium concentrations present a great pollutant potential to the environment. An example of this kind of effluent is the discharge of coke-plants, which presents, quantitatively, the phenols as the main organic compound. Inorganic compounds are also present in these wastewaters and are mainly cyanide, thiocyanate, sulphate and ammonium, the last one being able to achieve hundreds of milligrammes per litre. In Sao Paulo State, there are two legislations to be accomplished, State Decree 8468/76 and CONAMA Resolution 357/05 that stand that the polluters must accomplish the discharge limits of 20 mg N/L to total ammonium nitrogen and 0,5 mg C6H5OH/L to phenols, as well as accomplish the waterbody classification. The present research was planned after well succeded results of former researches in EPUSP\'s Hydraulic and Sanitation Engineering Department aiming to remove phenolic compounds and ammonium from a synthetic coke-plant wastewater, by nitrification/denitrification of the influent in activated sludge plants. The main purpose of this work was to remove nitrogen of a similar wastewater containing high phenol (1000 mg/L) and ammonium (500 a 1000 mgN/L) concentrations in two activated sludge pilot plants (single sludge): a partial one (\"P\") to remove nitrite (or \"nitritation/denitritation\") in the first case, only with internal carbon source for the denitrification, and a total one (\"T\") in a second case, with internal and external carbon sources. It was also aim of this work to compare the results obtained by the Partial (\"P\") pilot system with a parallel batch sequence reactor operated to remove nitrogen via nitrite. The research concluded that the continuos system, due to its operational characteristic, was not efficient to remove nitrogen via nitrite that does not favor the maintenance of free ammonia in the oxic phase in inhibitory concentrations to the nitrite oxidizers, as according to the wellsucceeded batch system, the existance of free ammonia and the pH have been the main parameters to raise the nitrite accumulation in the reactor. Nevertheless, the system presented satisfactory results to the denitrification with phenol as carbon source and, during the whole experimental work, the final effluent just showed despicable phenol concentrations. Summing up, continuos system was just adequate to remove nitrogen via nitrate, while the batch system favored its removal via nitrite. Due to the Total (\"T\") system which aims to complete nitrification/denitrification with internal and external carbon sources, the results showed that, despite ethanol having been successfully used by the heterotrophic bacteria to denitrification, its use as external carbon source was not adequate in single sludge system, because the microorganisms do not use phenol in denitrification, just using ethanol, causing phenol accumulation and unbalance of the system. Therefore, it was concluded that the use of ethanol as external carbon source to denitrification would be recommended only in anoxic separated reactor, i.e., in a double sludge system and not in a single sludge one, as this research.
4

Estudo da remoção de nitrogênio via nitrito e via nitrato em sistemas de lodo ativado alimentados por despejo com elevada concentração de fenol. / Study of nitrogen removal via nitrite and via nitrate in activated sludge systems fed by wastewater with high phenol concentration.

Mariana Vivolo Aun 11 October 2007 (has links)
Efluentes com grandes concentrações de fenol e nitrogênio amoniacal apresentam grande potencial poluidor ao meio ambiente. Exemplo deste tipo de despejo é o da unidade de coqueria da indústria siderúrgica que apresenta em termos quantitativos os fenóis como os principais constituintes orgânicos. Constituintes inorgânicos também estão presentes neste tipo de despejo e são principalmente cianeto, tiocianato, sulfato e nitrogênio amoniacal, sendo que a concentração deste último pode atingir níveis de centenas de miligramas por litro. No Estado de São Paulo, para atendimento às legislações em vigor - Decreto Estadual 8468/76 e Resolução CONAMA 357/05 - em termos de nitrogênio amoniacal e fenóis, as fontes poluidoras devem atender aos limites de emissão de 20 mg N/L para nitrogênio amoniacal total e 0,5 mg C6H5OH/L para índice de fenóis, e além disso, devem atender a classificação do corpo d\'água. Após resultados bem sucedidos de pesquisas realizadas anteriormente no Departamento de Engenharia Hidráulica e Sanitária da EPUSP objetivando remoção de compostos fenólicos e nitrogênio amoniacal, presentes em uma água residuária sintética de coqueria, através de nitrificação/desnitrificação do afluente em sistemas de lodo ativado, idealizou-se a presente pesquisa objetivando promover a nitrificação/desnitrificação de um despejo similar contendo altas concentrações de fenol (1000 mg/L) e nitrogênio amoniacal (500 a 1000 mgN/L) em sistema piloto de lodo ativado de lodo único, com duas concepções distintas: parcial (\"P\") a nitrito (ou \"nitritação/desnitritação\") em um primeiro caso, somente com fonte interna de carbono para a desnitrificação, e total (\"T\") num segundo caso, com fontes interna e externa de carbono. Além disso, também foi objetivo comparar os resultados obtidos do sistema piloto \"P\" com um sistema em bateladas seqüenciais operado paralelamente para remoção de nitrogênio via nitrito. A pesquisa permitiu concluir que o sistema contínuo, em virtude de seu regime operacional, não foi eficiente para remoção de nitrogênio via nitrito por não favorecer a manutenção de amônia livre na fase aeróbia em concentrações inibitórias aos microrganismos oxidadores de nitrito, já que segundo os resultados satisfatórios do sistema em bateladas seqüenciais, a existência de amônia livre e o pH se mostraram os principais parâmetros que regem o acúmulo de nitrito no reator. Apesar disso, o sistema apresentou resultados satisfatórios quanto à desnitrificação com fenol como fonte de carbono sendo que, durante toda a operação do sistema, o efluente final apresentou concentrações de fenol desprezíveis. Resumindo, o sistema contínuo só se mostrou adequado para remoção de nitrogênio via nitrato, ao passo que o sistema em batelada favoreceu a remoção via nitrito. Quanto ao sistema \"T\", que visava nitrificação/desnitrificação completa com fontes interna e externa de carbono, os resultados permitiram concluir que, apesar do etanol ser utilizado com eficiência pelas bactérias heterotróficas para promover a desnitrificação, seu uso como fonte externa de carbono não foi adequado em sistema de lodo único. Isto porque os microrganismos deixaram de utilizar o fenol na desnitrificação passando a utilizar somente o etanol, provocando acúmulo de fenol e desequilíbrio do sistema. Sendo assim, concluiu-se que o uso de etanol como fonte externa de carbono para a desnitrificação só seria recomendável em reator anóxico em separado, ou seja, em sistema de dois lodos e não de lodo único, como o da presente pesquisa. / Wastewaters containing high phenol and ammonium concentrations present a great pollutant potential to the environment. An example of this kind of effluent is the discharge of coke-plants, which presents, quantitatively, the phenols as the main organic compound. Inorganic compounds are also present in these wastewaters and are mainly cyanide, thiocyanate, sulphate and ammonium, the last one being able to achieve hundreds of milligrammes per litre. In Sao Paulo State, there are two legislations to be accomplished, State Decree 8468/76 and CONAMA Resolution 357/05 that stand that the polluters must accomplish the discharge limits of 20 mg N/L to total ammonium nitrogen and 0,5 mg C6H5OH/L to phenols, as well as accomplish the waterbody classification. The present research was planned after well succeded results of former researches in EPUSP\'s Hydraulic and Sanitation Engineering Department aiming to remove phenolic compounds and ammonium from a synthetic coke-plant wastewater, by nitrification/denitrification of the influent in activated sludge plants. The main purpose of this work was to remove nitrogen of a similar wastewater containing high phenol (1000 mg/L) and ammonium (500 a 1000 mgN/L) concentrations in two activated sludge pilot plants (single sludge): a partial one (\"P\") to remove nitrite (or \"nitritation/denitritation\") in the first case, only with internal carbon source for the denitrification, and a total one (\"T\") in a second case, with internal and external carbon sources. It was also aim of this work to compare the results obtained by the Partial (\"P\") pilot system with a parallel batch sequence reactor operated to remove nitrogen via nitrite. The research concluded that the continuos system, due to its operational characteristic, was not efficient to remove nitrogen via nitrite that does not favor the maintenance of free ammonia in the oxic phase in inhibitory concentrations to the nitrite oxidizers, as according to the wellsucceeded batch system, the existance of free ammonia and the pH have been the main parameters to raise the nitrite accumulation in the reactor. Nevertheless, the system presented satisfactory results to the denitrification with phenol as carbon source and, during the whole experimental work, the final effluent just showed despicable phenol concentrations. Summing up, continuos system was just adequate to remove nitrogen via nitrate, while the batch system favored its removal via nitrite. Due to the Total (\"T\") system which aims to complete nitrification/denitrification with internal and external carbon sources, the results showed that, despite ethanol having been successfully used by the heterotrophic bacteria to denitrification, its use as external carbon source was not adequate in single sludge system, because the microorganisms do not use phenol in denitrification, just using ethanol, causing phenol accumulation and unbalance of the system. Therefore, it was concluded that the use of ethanol as external carbon source to denitrification would be recommended only in anoxic separated reactor, i.e., in a double sludge system and not in a single sludge one, as this research.
5

Identification des sources d’alkylphénols et de phtalates en milieu urbain : comparaison des rejets à dominante urbaine (domestique) par rapport à des rejets purement industriels / Identification of the sources of alkylphénols and phtalates in urban zones : comparison of the discharges to urban dominant (domestic and home-made) with regard to purely industrial discharges

Bergé, Alexandre 16 November 2012 (has links)
Les phtalates et les alkylphénols sont des composés organiques générés par l'industrie chimique, qui entrent dans la composition des matières plastiques, pour les phtalates, et des détergents, pour les alkylphénols. Leurs productions mondiales avoisinent les 6 millions de tonnes pour les phtalates et 500 000 tonnes pour les alkylphénols. Ces composés sont considérés comme ubiquitaires dans l'environnement, c'est-à-dire qu'ils sont retrouvés dans tous les compartiments environnementaux (de l'atmosphère au milieu naturel). Par ailleurs, ils sont considérés comme des perturbateurs endocriniens et peuvent donc causer des dommages aux faunes et flores présentes dans le milieu naturel. Ce travail de thèse a permis de déterminer les niveaux de contamination des eaux usées en phtalates et alkylphénols dans plusieurs compartiments environnementaux situés en zone urbaine. Ainsi, des prélèvements effectués, par temps sec, ont permis de déterminer la qualité des eaux brutes vis-à-vis des paramètres globaux, des phtalates et des alkylphénols dans les rejets industriels, domestiques, les émissaires parisiens ainsi que dans les eaux usées transitant au sein d'une station d'épuration majeure d'Ile-de-France (Seine Centre, Colombes, 92). Ces résultats reflètent certaines spécificités et disparités du réseau d'assainissement, notamment marqués par la forte variabilité qui entoure, à la fois, le prélèvement et les niveaux de contamination par ces micropolluants. Au niveau des rejets industriels, de forts contrastes ont été observés entre les différents secteurs répertoriés (traitement des textiles, traitement de surface, métallurgie, industries pharmaceutiques, etc.). Globalement, les résultats des flux par équivalent-habitant soulignent que les apports domestiques sont la première source de contamination pour ces polluants en région parisienne. En effet, la contribution des apports industriels est inférieure à 5 %, pour tous les composés, quelque soit le secteur industriel considéré. L'étude des émissaires parisiens a permis de montrer une certaine stabilité temporelle de la qualité des effluents dans la partie avale du réseau d'assainissement. En revanche, cette étude a également mis en exergue des divergences et des similitudes entre les sous-bassins versants drainés par les différents émissaires. Ainsi, une étude statistique a montré que les émissaires Saint Denis Achères et Clichy Achères Argenteuil apparaissent significativement plus contaminés que les émissaires Sèvres Achères Reuil et Clichy Achères Bezons. Au niveau de l'efficacité des ouvrages de traitement, les résultats obtenus pour la station d'épuration de Seine Centre ont confirmé son efficacité pour les paramètres globaux communément utilisés pour déterminer la qualité des eaux usées. D'autre part, les résultats obtenus sur l'abattement des phtalates et des alkylphénols (rendements supérieurs à 83 % pour tous les composés) soulignent que même si les stations d'épuration ne sont, initialement, pas construites pour réduire et/ou éliminer les micropolluants, elles y parviennent de façon significative. A l'échelle des ouvrages, le traitement primaire par décantation physico-chimique lamellaire a permis de mettre en évidence l'élimination des polluants hydrophobes tels que le DEHP, le NP, le DnBP et le BBP. Le traitement secondaire par biofiltration a mis en exergue son efficacité à abattre significativement tous les polluants, aussi bien les composés légers (DEP) que les autres composés / Phthalates and alkylphenols are organic molecules generated by the chemical industry, entering the composition of plastics, for phthalates, and detergents for alkylphenols. Their worldwide productions are around 6 million tons and 500,000 tons, respectively. It is now obvious from the concentrations and contents measured in the various environmental compartments that phthalates and alkylphenols are ubiquitous environmental contaminants. Indeed, they are found in all environmental compartments (from the atmosphere to the natural environment) at significant levels. These contaminants are also recognized as endocrine disrupting compounds and can cause damages to fauna and flora present in the natural environment. This work has identified levels of wastewater contamination of phthalates and alkylphenols in various environmental compartments in urban areas. Thus, samples taken, during dry weather periods, were used to determine the quality of raw water for global parameters, phthalates and alkylphenols within industrial and domestical discharges as well as the sewer network and a major Parisian sewage treatment plant (Seine Centre, Colombes, 92). These results reflect certain characteristics and disparities of the sewer network, including both high variability of the sampling and the contamination levels by these micropollutants. For industrial discharges, significant disparities have been observed between the different sectors listed (textile manufacturing, surface treatment, metallurgy, pharmaceutical industries, etc.). Overall, the results confirm that household inputs correspond to the first source of contamination in Parisian conurbation. Indeed, the contribution of industrial inputs is less than 5%, for all compounds, whatever the industrial sector. The study of the Parisian sewer network showed some temporal stability of wastewaters in the downstream part. This work however also highlighted disparities and similarities between the sub-watersheds drained by the sewer network. Thus, the northern part of the Parisian network (SDA and CAA) appears to be more contaminated than the Southern part (CAB and SAR).The results obtained for Seine Centre wastewater treatment plant (WWTP) confirms the effectiveness of the treatment processes on the removal on the routine water quality parameters. Additionally, the results on the elimination of phthalates and alkylphenols in sewage treatment plant (yields above 83% for all compounds) confirm that even if WWTP are initially not designed for reducing and/or eliminating micropollutants, they proceed significantly. During primary treatment, physicochemical lamellar clarification underlined the removal of hydrophobic pollutants such as DEHP, NP, DnBP and BBP. During the secondary treatment, biofiltration highlighted its effectiveness in eliminating all pollutants, as well as volatile compounds (DEP) and other contaminants
6

Evaluación de la remoción de nitratos y fosfatos a nivel laboratorio por microalgas libres e inmovilizadas para el Tratamiento Terciario de Aguas Residuales Municipales

Ávila Peltroche, José Giovanni Jesús January 2015 (has links)
El presente estudio tuvo como objetivo determinar la capacidad de remoción de nitratos (N-NO3⁻) y fosfatos (PO₄³¯) en Aguas Residuales Municipales (ARM) por microalgas libres e inmovilizadas. Se utilizaron cepas provenientes de los afluentes de la Planta de Recuperación de las Aguas del Río Surco (Lima, Perú) y se evaluó su capacidad de remoción de N-NO3⁻ y PO₄³¯ durante 10 días, a nivel laboratorio, en ARM con tratamiento primario, tanto de forma libre como inmovilizadas en discos de alginato de sodio al 4%. Los cepas obtenidas se identificaron como Chlorella sp y Chlamydomonas sp. Ambas tuvieron un buen crecimiento en ARM, especialmente Chlamydomonas sp, la cual reportó los mayores valores en los parámetros cinéticos de crecimiento. El cultivo de Chlorella sp. libre fue el que registró uno de los valores más altos de porcentaje (71.25%) y tasa de remoción (0.43 mg/l/día) de N-NO3⁻, y los máximos valores de dichos parámetros para PO43- (83.69%; 0.09 mg/l/día), así como para el índice de eficacia (EI) de ambos nutrientes, comparado con los de Chlamydomonas sp. Los cultivos inmovilizados de ambas especies reportaron valores altos de remoción, entre 56% a 67% para N-NO3⁻ y 78% a 81% para PO43-, este último fue removido en 24 horas en la mayoría de los cultivos. La inmovilización fue el principal factor que afectó la capacidad de remoción de nutrientes. Ambas cepas mostraron ser eficientes en la remoción de nutrientes en ARM, especialmente de PO43-, con valores cercanos a los máximos reportados para ambas especies en estudios previos.The aim of this investigation was to determinate the nitrate (N-NO3⁻) and phosphate (PO43-) removal capacity of free and immobilized microalgae in Municipal Wastewater (MW). Strains were isolated from Planta de Recuperación de las Aguas del Río Surco (Lima, Perú) influent. Their N-NO3⁻ and PO43- removal capacity were evaluated during 10 days in MW with primary treatment in batch cultures with free and immobilized cells in 4% sodium alginate discs. Strains were identified as Chlorella sp and Chlamydomonas sp. Both showed good growth in MW, especially Chlamydomonas sp., which reported the highest value of kinetic growth parameters. Free Chlorella sp. culture reported one of the highest values of N-NO3- removal percentage (71.25%) and rate (0.43 mg/l/día), and the maximum values of PO43- removal parameters (83.69%; 0.09 mg/l/día) and efficacy index (EI) for both nutrients compared with Chlamydomonas sp. Immobilized cultures reported high values of nutrient removal, between 56% to 67% for N-NO3⁻ and 78% to 81% for PO43-. In most microalgae cultures, high percentages of PO43- (76-80%) were removed in 24 hours. Method of culture (free or immobilized) was the main factor affecting the nutrient removal capacity. Strains were efficient in nutrient removal in MW, especially for PO43-, with values close to the maximum ones reported for both species in previous studies.
7

Investigation of Direct-Reduced Iron as a Filter Media for Phosphorus Removal in Wastewater Applications

Qin, Hongye 18 December 2019 (has links)
Passive reactive filters have the potential to provide effective phosphorus (P) removal from stormwater or agricultural drainage, or to act as an add-on P-removal technology for decentralized or small community wastewater treatment systems. Passive filters require minimal energy consumption and human maintenance. Direct-reduced iron (DRI), a steel-making intermediate, was investigated as a passive filter media for wastewaters phosphorus reduction. Phosphorus is a biologically active element that is in excess in many natural waterways due to intensive human activity. Eutrophication can occur when P concentrations exceed 0.02 mg/L in freshwater lakes and rivers. The harmful consequence of this phenomenon includes oxygen deprivation, fish death and cyanobacteria-produced toxins. There is a pressing need to limit phosphorus over-discharge into natural waterways. DRI is a novel media in the application of wastewater treatment and was characterized to have a porous structure with high metallic iron content. The phosphorus retaining mechanisms in batch and column studies suggest a combination of adsorption and surface crystal formation as the dominant removal mechanisms. Batch studies demonstrated increasing removal capacity with P concentration with a plateau observed at 21 mg P/g DRI relating to initial 3000 mg P/L. Media rejuvenation was investigated through chemical treatment with two iron solutions (Fe2(SO4)3, FeCl3) and two acidic solutions (H2SO4 and HCl) at varying molarity. P removal capacity could be fully recovered with 0.05 M Fe3+ or 0.4 N H+ (HCl/H2SO4), while a 37.6% P recovery was also achieved in an acidic solution at 1.2 N H+ (HCl/H2SO4). A column study utilizing three media sizes of DRI (3.5, 11, 19 mm) and one media size of activated alumina (AA) (7.5 mm) was conducted for 315 days using synthetic P solution varying from 2 to 10 mg/L and hydraulic retention times (HRTs) varying from 0.7 – 15 h. The results demonstrated that removal efficiency increased with HRT and decreased with increasing media size and concentration with minimum HRTs to maintain an 80% removal efficiency varying from 4.4 to 15 hrs for DRI and 3.9 hrs for AA for influent P concentrations of 10 mg/L and below. After 1 year of column operation, the DRI media had demonstrated a minimum removal capacity of 1.82 mg P/g DRI, which can be used as a conservative design parameter. A short duration column study (34 days) utilizing municipal lagoon effluent exhibited similar removal efficiencies to the synthetic column study under the same operational conditions. The 10 years lifespan DRI filter with 80% removal rate in the treatment of stormwater, municipal lagoon effluent, septic tank effluent and dairy wastewater application would have been estimated to have filter volumes of 0.24, 4.69, 15.3 and 36.2 m3, respectively.
8

Sustainable Management of Duckweed Biomass Grown for Nutrient Control in Municipal Wastewaters

Kesaano, Maureen 01 May 2011 (has links)
The use of duckweed as a nutrient removal option for municipal wastewaters can only be realized through regular plant harvesting. As a result, the nutrient-rich biomass generated needs to be effectively managed and disposed of. This study looked at three alternative options for biomass management that would make duckweed-based nutrient removal systems sustainable and attractive to small communities like Wellsville City, Utah. The options included: the use of harvested duckweed biomass as an animal feed, anaerobic digestion of duckweed for methane production, and fermentation of biomass for ethanol production. Duckweed feed quality was determined using feed analysis reports and results from digestibility studies (in vitro fermentation). The performance of the anaerobic digestion process was determined by monitoring pH, VS, TS, NH4-N, VFAs, and alkalinity. The ethanol production yields were obtained from starch content values and ethanol concentrations observed from batch fermentation experiments. Duckweed was composed of 21 - 38% crude protein, 94 - 96% water, 78.5% organic matter, < 10% starch and an average of 19% starch after accumulation by nutrient starvation. Relative feed values (RFVs) of 230 - 241, crude protein content of 21-38%, and neutral and acid detergent fiber values of 30.2% and 13.7%, respectively, showed duckweed as a potential feed for ruminants comparable to alfalfa and corn silage (RFVs of 100). Digester performance showed an average methane yield of 6.3 and 5.8 ft3/lb VS destroyed with methane composition values of 67.1% and 62.5% for fresh DW fed reactor (R1) and air dried DW fed reactor (R2), respectively. The ethanol production yield observed was less than 100 mg ethanol/g DW for both fresh and oven dried DW samples. The recommended duckweed biomass management option for a small community like Wellsville is anaerobic digestion because it is a source of energy and at the same time the digestate can be used as a low-quality feed.
9

UtilizaÃÃo de Ensaios de Ecotoxicidade no Biomonitoramento de Efluentes de Etes Industriais, Hospitalares e De Aterro SanitÃrio, Localizadas no Estado do Cearà / Use of ecotoxicity tests on Biomonitoring of Industrial Effluents Etes, Hospital and Sanitary Landfill, located in the State of Ceara

MÃrcia Rodrigues de Sousa 29 September 2010 (has links)
CoordenaÃÃo de AperfeiÃoamento de NÃvel Superior / Avaliou-se o uso de testes de ecotoxicidade com o organismo-teste Daphnia magna no biomonitoramento de efluentes de ETEs industriais (real e sintÃtico), hospitalares e de aterro sanitÃrio. Para tanto, foram selecionadas algumas ETEs a citar: Industrial Real (Sistema Integrado do Distrito Industrial â SIDI), Industrial SintÃtico (Reator anaerÃbio seguido dos pÃs-tratamentos em Reator em Batelada SeqÃencial â RBS e Processo de OxidaÃÃo AvanÃado â POA do tipo H2O2/UV, tratando um efluente contendo o corante azo Reactive Black 5 - RB5), Hospitalar (Hospital Geral Waldemar de AlcÃntara â HGWA) e Aterro SanitÃrio (Lixiviado coletado na saÃda do sistema de lagoas de estabilizaÃÃo do Aterro SanitÃrio Metropolitano Oeste de Caucaia â ASMOC e submetido a um pÃs-tratamento por meio de um Reator Aerado Submerso â RAS). Os testes de toxicidade aguda realizados com o lixiviado indicaram que o efluente ao sistema ASMOC apresentou CE50 de 68%, o qual podia ser classificado como moderadamente tÃxico. Assim, alÃm de alguns parÃmetros fÃsico-quÃmicos nÃo estarem atendendo à Portaria n 154/02 da SEMACE, os resultados ecotoxicolÃgicos confirmaram o potencial poluidor do lixiviado em questÃo para ser descartado no Riacho Garoto, de baixa capacidade de diluiÃÃo. O pÃs-tratamento aerÃbio realizado no RAS contribuiu bastante na reduÃÃo da toxicidade do lixiviado, tanto em termos fÃsico-quÃmicos quanto em termos ecotoxicolÃgicos, aumentando o valor de CE50 para 95,04%, se configurando como uma boa opÃÃo de pÃs-tratamento. Os resultados obtidos com o esgoto afluente e efluente ao SIDI revelaram que o CE50 passou de 18,05% para 61,90%, mudando a classificaÃÃo de muito tÃxico para moderadamente tÃxico, respectivamente. Entretanto, o estudo efluente do SIDI, com as caracterÃsticas fÃsico-quÃmicas e de toxicidade encontradas, associadas à elevada vazÃo de esgotos tratados, representam um sistema com uma carga poluidora que merece ser investigada no corpo receptor. Em relaÃÃo ao esgoto hospitalar, observou-se que o esgoto bruto apresentou alta toxicidade e um CE50 de 7,27% (muito tÃxico) enquanto que o efluente tratado pela seqÃÃncia de reator UASB e lodo ativado apresentou CE50 de 30,83% (tÃxico). Portanto, os ensaios ecotoxicolÃgicos apontaram para o carÃter tÃxico do efluente em termos agudos, e podemos inferir a toxicidade crÃnica que tal efluente pode causar no corpo hÃdrico, jà que o mesmo pode conter elevadas concentraÃÃes de fÃrmacos, hormÃnios e outros micro-poluentes. O efluente sintÃtico bruto contendo o corante RB5 apresentou CE50 de 23,02%, sendo classificado como efluente muito tÃxico. ApÃs o tratamento no reator UASB, o valor de CE50 caiu para 40,34%, ou seja, houve uma diminuiÃÃo da toxicidade no tratamento anaerÃbio. No pÃs-tratamento pelo RBS ocorreu uma diminuiÃÃo significativa de toxicidade, em que o mesmo pode ser classificado como nÃo tÃxico. Entretanto, o POA do tipo do tipo UV/H2O2 provocou aumento da toxicidade, com o efluente apresentando CE50 de 20,17%, recebendo classificaÃÃo de muito tÃxico. A investigaÃÃo ecotoxicolÃgica em D. magna para avaliar o efeito da concentraÃÃo de H2O2 revelou elevada toxicidade do residual de perÃxido, sendo que em todas as diluiÃÃes testadas houve morte de 100% dos organismos expostos. Portanto, os estudos indicaram que muito embora o processo de oxidaÃÃo avanÃado (POA) do tipo H2O2/UV tenha uma boa perspectiva de aplicaÃÃo no tratamento de esgotos recalcitrantes, o perÃxido residual tem que ser cuidadosamente monitorado, nÃo sà por elevar a DQO do efluente como tambÃm por aumentar a toxicidade deste. Como conclusÃo geral da presente dissertaÃÃo foi possÃvel demonstrar a grande importÃncia dos testes ecotoxicolÃgicos agudos e crÃnicos no biomonitoramento de cargas poluidoras localizadas em corpos de Ãgua do CearÃ, assim como para um melhor entendimento dos processos biolÃgicos e nÃo biolÃgicos de tratamento de esgotos. / We evaluated the use of ecotoxicity tests with Daphnia magna for the biomonitoring of industrial effluents (real and synthetic), hospital effluent and leachate: real industrial wastewater (Integrated System of Industrial District - SIDI), synthetic industrial wastewater (anaerobic reactor followed by the post-treatments Sequential Batch Reactor - SBR and Advanced Oxidation Process - AOP type H2O2/UV, both treating a wastewater containing the azo dye Reactive Black 5 - RB5), Hospital effluent (Hospital Geral Waldemar de AlcÃntara - HGWA) and Leachate collected at the output of the stabilization ponds system located at the Metropolitan Sanitary Landfill West of Caucaia - ASMOC and submit to the post-treatment of Submerged Aerated Reactor - SAR. The acute toxicity tests conducted with the leachate indicated that the effluent from ASMOC system showed EC50 of 68%, which could be classified as moderately toxic. Thus, in addition to some physical and chemical parameters that are not complying with the limits defined in the Portaria nÂ. 154/02 of SEMACE, ecotoxicological results confirm the pollution potential of the leachate to be discharged at the Riacho Garoto, which has low dilution capacity. The post-aerobic treatment performed in SAR showed to greatly contribute in reducing the leachate toxicity in terms of physical-chemical and ecotoxicological characteristics, increasing the EC50 value to 95.04%, and showing to be a good post-treatment option. The results obtained with the real industrial influent and effluent from SIDI revealed that the EC50 increased from 18.05% to 61.90%, switching the classification from very toxic to moderately toxic, respectively. However, the SIDI effluent, considering the physico-chemical properties and toxicity found, associated with the high flow rate of treated wastewater, represents a system with a pollutant load that should be further investigated in the receiving water body. Regarding the hospital wastewater, it was observed that the raw wastewater had a high toxicity, with EC50 of 7.27% (very toxic), while the effluent treated by the sequence of UASB and activated sludge showed EC50 of 30.83% (toxic). Therefore, ecotoxicological tests revealed the toxic character of the effluent in terms of in acute toxicity and it can infer the chronic toxicity that such an effluent can cause in the water body, since it may contain high concentrations of drugs, hormones and other micro-pollutants. The synthetic wastewater containing the azo dye RB5 presented EC50 of 23.02%, classified as very toxic. After treatment in the UASB reactor, the EC50 value increased to 40.34%, i.e. there was a toxicity decrease by the anaerobic treatment. In the post-treatment by SBR, a significant reduction of toxicity was found and the effluent could be classified as non-toxic. However, the UV/H2O2 AOP increased the toxicity, in other words the EC50 decreased to 20.17%, being classified as very toxic. The effect of H2O2 concentration on the ecotoxicological test with D. magna was assessed and showed high toxicity of the residual peroxide, in all dilutions tested, causing death of 100% of the exposed organisms. Therefore, the studies indicated that although the H2O2/UV advanced oxidation process (AOP) has a good prospect for application on recalcitrant compounds, the peroxide residual has to be carefully monitored, not only because it increases the wastewater COD but also because it increases the effluent toxicity. As a general conclusion of this research, it was possible to show the great importance of acute and chronic ecotoxicological tests for the biomonitoring of pollution sources located in CearÃ, and also for a better understanding of biological and non-biological processes applied to wastewater treatment.
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Processo de separação por membranas para remoção de sulfato de níquel e zinco de efluente sintético de indústrias metal-mecânicas / Membrane separation process to removal Ni e Zn

Luciana Maria Baptista Ventura 14 February 2008 (has links)
Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro / O objetivo do presente trabalho foi investigar o desempenho de membranas comerciais e funcionalizadas na remoção de metais pesados de efluentes sintéticos, simulando os efluentes gerados pelas indústrias metal-mecânicas. As membranas funcionalizadas foram preparadas em laboratório a partir de diferentes poli (éter imidas) sulfonadas, SPEI, que apresentavam alta hidrofilicidade e capacidade de troca iônica. As permeabilidades hidráulicas das membranas de SPEI aumentaram com o grau de sulfonação. Porém, as rejeições foram ainda muito baixas comparadas as membranas comerciais. Por esta razão, algumas membranas comerciais (NF-90, SW30, HRP98PP e BW30LE) foram investigadas e avaliadas quanto ao comportamento da permeabilidade de água e o grau de rejeição a metais pesados. Os resultados mostraram que a membrana de osmose inversa de baixa energia (BW30LE) tinha o melhor fluxo de água (48,44 L/h.m2) e grau de rejeição a cádmio (98%). Logo, ela foi selecionada para o tratamento dos efluentes sintéticos de indústrias metal-mecânicas contendo níquel e zinco. As indústrias da região de Valencia, na Espanha, forneceram amostras de seus efluentes para análise quantitativa, possibilitando o prepararo de soluções sintéticas modelos. Os resultados foram obtidos variando algumas condições de permeação, tais como a força motriz, o pH e a concentração dos metais na solução de alimentação. Os resultados indicaram que o processo de osmose inversa com a membrana BW30LE é altamente adequado para o tratamento de efluentes contendo metais pesados / The presente work aims to investigate the performance of new functionalized membranes and commercial membranes for heavy metal removal from aqueous effluents. The functionalized membranes were prepared from different sulfonated polyetherimide, SPEI, exhibiting high hydrophilicity and ion exchange capacity. The water permeability of SPEI membranes increased with the sulfonation degree, but with lower saline rejection than commercial membranes. Therefore, commercial membranes (NF-90, SW30, HRP98PP and BW30LE) were used to investigate the relationship between the water permeability and the metals retention. The highest water flux (48.44 L/h.m2) and cadmium rejection (98%) were observed using a reverse osmosis membrane (BW30LE). Then, it was selected to investigate the permeation of a synthetic wastewater containing nickel and zinc as poluted elements. The synthetic solutions were prepared considering samples supplied by industries in the Valencia region, in Spain, which were analyzed quantitatively. The permeation results showed that the membrane performance changed with the driven force (pressure), the pH solution and the metals concentration. The BW30LE membrane showed the best performance for removal of heavy metal in the wastewater treatment

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