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Efici?ncia de uma ETE em escala real composta por reator UASB seguido de lodo ativado / Efficiency of a full-scale WWTP consists of UASB reactor followed by activated sludgeFerraz, Danillo Luiz de Magalh?es 07 March 2014 (has links)
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Previous issue date: 2014-03-07 / In the state of Rio Grande do Norte (RN), Brazil, there are about 80 sewage
treatment systems being the predominant technology waste stabilization ponds. The
Baldo s WWTP , due to its location and low availability of area, was designed as a
hybrid conventional system (UASB reactor followed by activated sludge with
biodiscs) at a tertiary level, being the most advanced WWTP in the State and also
with the larger treatment capacity (1620 m3/h) .The paper presents the results of its
performance based on samples collections from May to December 2012. Composite
samples of the effluent of the grit chamber, UASB reactors, anoxic chambers,
aeration tanks and treated effluent were collected weekly, every 4 hours for 24 hours.
The results showed that the WWTP effluent presented adequate ranges of
temperatures, pH and DO, however removal efficiencies of BOD and TSS were
below the predicted by design. The UASB reactors also showed removals of BOD
and TSS less than expected, due to the accumulation of sludge in the reactors, which
eventually, was washed out in the effluent. The nitrification process was not
satisfactory mainly due to problems in the oxygen distribution in the aeration tanks.
The removal of ammonia and TKN were high, probably by the assimilation process / No Rio Grande do Norte (RN), Brasil existe cerca de 80 sistemas de tratamento de
esgotos sendo a tecnologia das lagoas de estabiliza??o a predominantemente
utilizada. A ETE do Baldo, devido a sua localiza??o e disponibilidade de ?rea foi
concebida como um sistema convencional h?brido (UASB lodos ativados com
biodiscos) em n?vel terci?rio, sendo a ETE mais avan?ada do Estado e com maior
capacidade de tratamento (1620 m
3
/h). O trabalho apresenta os resultados do seu
monitoramento, atrav?s de coletas realizadas semanalmente no per?odo de junho a
dezembro de 2012, com base em amostras compostas coletadas a cada 4 horas,
durante 24 horas, do efluente da caixa de areia, reatores UASB, c?maras an?xicas,
tanques de aera??o e efluente tratado. Os resultados mostraram que a ETE
apresentou efluentes com temperaturas, pH e OD adequados, entretanto efici?ncias
abaixo do projetado para os par?metros DBO e SST. Os reatores UASB tamb?m
apresentaram remo??es de DBO e SST abaixo do esperado, devido ao ac?mulo de
lodo nos reatores, uma vez que, este era expelido no efluente. O processo de
nitrifica??o n?o foi satisfat?rio, pelas baixas concentra??es de nitrato encontradas
nos efluentes dos tanques de aera??o, provavelmente por problemas no sistema de
aera??o. As remo??es de am?nia e NTK foram altas, provavelmente pelo processo
de assimila??o
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Metabolic network modelling of nitrification and denitrification under cyanogenic conditionsMpongwana, Ncumisa January 2019 (has links)
Thesis (PhD (Chemical Engineering))--Cape Peninsula University of Technology, 2019 / Simultaneous nitrification and aerobic denitrification (SNaD) is a preferred method for single stage total nitrogen (TN) removal, which was recently proposed to improve wastewater treatment plant design. However, SNaD processes are prone to inhibition by toxicant loading with free cyanide (CN-) possessing the highest inhibitory effect on such processes, rendering these processes ineffective. Despite the best efforts of regulators to limit toxicant disposal into municipal wastewater sewage systems (MWSSs), free cyanide (CN-) still enters MWSSs through various pathways; hence, it has been suggested that CN- resistant or tolerant microorganisms be utilized for processes such as SNaD. To mitigate toxicant loading, organisms in SNaD have been observed to adopt a multiphase growth strategy to sequentially degrade CN- during primary growth and subsequently degrade TN during the secondary growth phase. However, CN- degrading microorganisms are not widely used for SNaD in MWSSs due to the inadequate application of suitable microorganisms (Chromobacterium violaceum, Pseudomonas aeruginosa, Thiobacillus denitrificans, Rhodospirillum palustris, Klebsiella pneumoniae, and Alcaligenes faecalis) commonly used in single-stage SNaD.
The use of CN- degrading or resistant microorganisms for SNaD is a cost-effective method compared to the use of other methods of CN- removal prior to TN removal, as they involve multi-stage systems (as currently observed in MWSSs). The use of CN- degrading microorganisms, particularly when used as a consortium, presents a promising and sustainable resolution to mitigate inhibitory effects of CN- in SNaD. However, SNaD is known to be completely inhibited by CN- thus it is imperative to also study some thermodynamic parameters of SNaD under high CN- conditions to see the feasibility of the process. The Gibbs free energy is significant to understand the feasibility of SNaD, it is also vital to study Gibbs free energy to determine whether or not the biological reaction is plausible. The relationship between the rate of nitrification and Gibbs free energy was also investigated.
The attained results showed that up to 37.55 mg CN-/L did not have an effect on SNaD. The consortia degraded CN- and achieved SNaD, with degradation efficiency of 92.9 and 97.7% while the degradation rate of 0.0234 and 0.139 mg/L/hr for ammonium-nitrogen (NH4-N) and CN- respectively. Moreover, all the free Gibbs energy was describing the individual processes were found to be negative, with the lowest Gibbs free energy being -756.4 and -1830.9 Kcal/mol for nitritation and nitratation in the first 48 h of the biological, reaction respectively. Additionally, a linear relationship between the rate of NH4-N and nitrite-nitrogen (NO2-N) degradation with their respective Gibbs free energy was observed. Linear model was also used to predict the relationship between NH4-N, NO2-N degradation and Gibbs free energy. These results obtained showed a good correlation between the models and the experimental data with correlation efficiency being 0.94 and 0.93 for nitritation, and nitratation, respectively. From the results found it can be deduced that SNaD is plausible under high cyanide conditions when cyanide degrading or tolerant microorganisms are employed. This can be a sustainable solution to SNaD inhibition by CN- compounds during wastewater treatment.
Furthermore, a single strain was purified from the consortium and identified as Acinetobacter courvalinii. This bacterial strain was found to be able to perform sequential CN- degradation, and SNaD; an ability associated with multiphase growth strategy of the microorganism when provided with multiple nitrogenous sources, i.e. CN- and TN. The effect of CN- on nitrification and aerobic denitrification including enzyme expression, activity and protein functionality of Acinetobacter courvalinii was investigated. It was found that CN- concentration of up to 5.8 mg CN-/L did not affect the growth of Acinetobacter courvalinii. In cultures whereby the A. courvalinii isolate was used, degradation rates of CN- and NH4-N were found to be 2.2 mg CN-/L/h and 0.40 mg NH4-N/L/h, respectively. Moreover, the effect of CN- on NH4-N, nitrate-nitrogen (NO3-N) and NO2-N oxidizing enzymes was investigated, with findings indicating CN- did not affect the expression and activity of ammonia monooxygenase (AMO), but affected the activity of nitrate reductase (NaR) and nitrite reductase (NiR). Nevertheless, a slow decrease in NO2-N was observed after the addition of CN- thus confirming the activity of NaR and the activation of the denitrification pathway by the CN-. Moreover, five models’ (Monod, Moser, Rate law, Haldane, and Andrew’s model) ability to predict SNaD under CN- conditions, indicated that only Rate law, Haldane and Andrew’s models, were suited to predict both SNaD and CN- degradation. Due to low degradation rates of NH4-N and CN-, optimization of SNaD was essential. Therefore, response surface methodology was used to optimize the SNaD under CN- conditions.
The physiological parameters that were considered for optimization were temperature and pH; with the result showing that the optimum for pH and temperature was 6.5 and 36.5oC respectively, with NH4-N and CN- degradation efficiency of 50 and 80.2%, respectively. Furthermore, the degradation kinetics of NH4-N and CN- were also studied under the optimum conditions in batch culture reactors, and the results showed that up to 70.6% and 97.3% of NH4-N and CN- were simultaneously degraded with degradation rates of 0.66 and 0.41 mg/L/h, respectively. The predictive ability of RSM was further compared with cybernetic models, and cybernetic models were found to better predict SNaD under CN- conditions. These results exhibited a promising solution in the management of inhibition effected of CN- towards SNaD at an industrial scale.
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Control basat en lògica difusa per sistemes de fangs activats. Disseny, implementació i validació en EDAR realsFiter i Cirera, Mireia 24 March 2006 (has links)
En aquesta tesi es presenten dues propostes de Sistemes de Control basats en Lògica Difusa (SCLD), des del seu disseny fins a la seva implementació i validació en dues instal·lacions: l'EDAR Granollers i l'EDAR Taradell.El capítol 1 explica els conceptes bàsics per comprendre el desenvolupament dels dos SCLD i el resum d'una revisió d'articles que relacionen la lògica difusa amb aigües residuals. A continuació, s'estableixen els objectius. En el capítol 3 es presenten els materials i mètodes. Els capítols 4 i 5 exposen el treball realitzat per arribar a la implementació dels dos SCLD. Ambdós capítols presenten la mateixa estructura: presentació, definició dels objectius del SCLD, descripció de l'EDAR on s'implementa el SCLD, desenvolupament d'índexs d'avaluació, explicació del disseny del SCLD i la seva avaluació mitjançant estudis de simulació, implementació i validació del SCLD a l'EDAR i, finalment discussió del treball realitzat. En el capítol 6 s'enumeren les conclusions obtingudes. / This thesis presents two proposals of Fuzzy Logic Control Systems (FLCS's), from their design to their implementation and validation in two facilities: Granollers and Taradell WWTP. The fundamental concepts to understand the FLCS's development are explained in the first chapter with a summary of scientific papers related to fuzzy logic applications in the wastewater treatment. The objectives are established in Chapter 2 and the materials and methods are described in Chapter 3.In Chapters 4 and 5, the work to design, implement and validate the FLCS's is presented. Both chapters have the same structure: a presentation, a goal definition of FLCS, a description of the WWTP, the evaluation index development, a detailed explanation about designing the FLCS process and its evaluation by simulation studies, the implementation of FLCS to WWTPs and their validation and, finally, a discussion of the work carried out is presented. The main conclusions are enumerated in Chapter 6.
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