Thesis (doctoral)--Universität Kiel, 1995. / Includes bibliographical references (p. 110-129).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1968. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliography.

Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves [135]-139). Also available on the Internet.

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.

Diploma thesis Effect of emergent micropolutants on the denitrification process through activated sludge is focused on three specific substances. The substances under investigation are atrazine, terbutylazine and sulfametaxazole. Atrazine and terbutylazine are pesticides, particularly herbicides. Sulfametaxazole was chosen as a common antibiotic. The thesis is summarized into 10 chapters and conclusion. The work consists essentially of theoretical and practical part. Part of the theoretical part of the thesis is legislation that deals with the matters of the problem with micropolutants. The next chapter is an introduction to the issue, where we want to familiarize the reader with the current situation. There are also chapters on emergent micropolutants, denitrification and investigated substances. If we look at the practical part, there are chapters on sampling, evaluation of BATCH tests and evaluation of inhibition tests. There are also chapters on BATCH tests and respiratory inhibition test, which describe procedures of how we performed this test. Laboratory test reports are included in the Annex.

There are many advantages and some disadvantages associated with the fall application of nitrogen fertilizers. The advantages of applying fertilizer at this time appear very convincing. It is easier to get onto the land in the fall. During the fall, famers usually have more time to apply fertilizer than they do in the spring. In the fall the fertilizer companies offer better service. This is because the fall application of fertilizer lengthens out their season, thus making it possible for them to handle more fertilizer.

Nitrification, the process whereby ammonical-nitrogen (NH i+4 - N) is changed into nitrate- nitrogen (NO3-N), is one of the more important biochemical processes associated with agriculture. Nitrate appears to be the form of N that most crops can most readily utilize.

No description available.

<p> This work examines the feasibility of continuous biological nitrification and denitrification for nitrogen removal from municipal wastewater. Pilot plant'studies were conducted using a rotating biological contactor (RBC) for nitrification and upflow packed columns for denitrification. Of primary interest were the effects of temperature on the systems. </p> <P> It was found that an Arrhenius model adequately described nitrification rates measured over a range of temperatures from 7 degrees C to 250 degrees C. Direct comparison of the Arrhenius Activation Energies determined for the RBC and a two stage activated sludge system with intermediate clarification showed that nitrification in the RBC was less temperature sensitive than in the activated sludge process. At 10 degrees C, roughly 20 mg/hr·m^2 (0.10 lb/day•1000 ft^2 ) of ammonia as nitrogen was removed from the system. </p> <p> The rate of denitrification in the packed column reactors displayed great variability. The temperature dependency of the data could not be characterized by an Arrhenius model or any other simple relationship. Although significant nitrate removal was observed at all temperatures between 5°C and 25°C, severe short circuiting due to solids accumulation tended to limit minimum nitrate effluent concentrations to 1 or 2 mg N03^-N/~. </p> / Thesis / Master of Engineering (MEngr)

No description available.