Anaerobic digestion (AD) has been shown to be an effective technique for energy recovery and stabilization of livestock wastes, municipal sludges and industrial wastewaters. However, further treatment is required to remove nitrogen from AD effluents to avoid detriments to surface and ground waters. The high free ammonia (FA) concentrations present in AD effluents can inhibit nitrification processes in conventional biological nitrogen removal (BNR) systems. The overall goal of this research was to develop a process for removal of nitrogen from AD swine waste (ADSW) effluent. The proposed solution was to incorporate particulate chabazite, which has a high cation exchange capacity, into a sequencing batch reactor (SBR) to adsorb ammonium and therefore ease nitrification inhibition. The process developed is called a chabazite-SBR. Three research questions were used to guide this research. First question (Chapter 3): How does chabazite pretreatment with groundwater (GW) affect the kinetics and cation exchange capacity during ammonium (NH4+) uptake? Kinetics and isotherm batch tests were performed with GW pretreated chabazite. In addition, sodium chloride (NaCl), and deionized water (DI) pretreated chabazite was included for comparison because these are typically used pretreatment methods. The Ion Exchange (IX) isotherm model was used to calculate the cation exchange capacity and the pseudo-first and film diffusion kinetics models were applied to quantify the effect of the pretreatment on the reaction rate. Results showed that the exchange capacity was slightly higher for GW pretreated chabazite compared with the other common pretreatment strategies; however, the enhancement was not significantly different. The kinetics of NH4+ uptake during the first four hours of contact was significantly improved by GW pretreatment when compared with other common pretreatment strategies. This was caused by an enhancement in film diffusion mechanisms. The findings of this first part of the research were important because it was shown that NaCl pretreatment is not needed to improve the kinetics and cation exchange capacity of chabazite. Second question (Chapter 4): How does addition of chabazite to ADSW centrate affect nitrification rates? Nitrification batch test with varying NH4+ concentrations were performed to identify the inhibitory NH4+ concentration. Additional nitrification batch tests treating real and synthetic waste with initial NH4+ concentration of 1,000 mg-N L-1 with added zeolite were performed. For the mixed liquor tested in this study, NH4+ concentrations must be maintained below 200 mg-N L-1 to relieve nitrification inhibition. Treatment of ADSW centrate requires a chabazite dose of 150 g L-1 to ease FA inhibition of nitrification. The rate of nitrification increased, by approximately a factor of 3, when chabazite was added to a batch reactor treating high NH4+ strength wastewater. However, Na+ release from the chabazite also plays a role in nitrification inhibition. The findings of this part of the research showed the potential for using chabazite for overcoming FA inhibition of nitrification during treatment of high NH4+ strength wastewater. Third question (Chapter 5): How effective is the chabazite-SBR in removing total nitrogen concentrations from ADSW centrate? A chabazite-SBR was operated for 40 weeks (cycles) to study the TN removal efficiency with varying carbon source. The efficiency of IX was also monitored over time. The chabazite-SBR process achieved stable TN removal from ADSW centrate during the 40 weeks of operation. Simultaneous nitrification-denitrification reduced chemical input requirements. Addition of an external organic carbon source at a rate of 3.2 g-COD g-N-1 resulted in maximum TN removal. An overall TN removal efficiency of 84% was achieved, with specific nitrification and denitrification rates of 0.43 and 1.49 mg-N g-VSS-1 hr-1, respectively. The IX stage of the chabazite-SBR was able to reduce FA concentrations to below the inhibitory level for nitrification inhibition over 40 chabazite-SBR cycles with no loss in IX efficiency over time and no fresh zeolite added to the reactor.

Advanced wastewater treatment plants have complex biological kinetics, time variant influent rates and long processing times. The modeling and operation control of wastewater treatment plant gets complicated due to these characteristics. However, a robust operational system for a wastewater treatment plant is necessary to increase the efficiency of the plant, reduce energy cost and achieve environmental discharge limits. These discharge limits are set by the National Pollutant Discharge Elimination System (NPDES) for municipal and industrial wastewater treatment plants to limit the amount of nutrients being discharged into the aquatic systems. This document summarizes the research to develop a supervisory operational and control system for the Valrico Advanced Wastewater Treatment Plant (AWWTP) in the Hillsborough County, Florida. The Valrico AWWTP uses biological treatment process and has four oxidation ditches with extended aeration where simultaneous nitrification and denitrification (SND) takes place. Each oxidation ditch has its own anaerobic basin where in the absence of oxygen, the growth of microorganisms is controlled and which in return also helps in biological phosphorus removal. The principle objective of this research was to develop a working model for the Valrico AWWTP using BioWin which mimics the current performance of the plant, predicts the future effluent behavior and allows the operators to take control actions based on the effluent results to maintain the discharge permit limits. Influent and experimental data from online and offline sources were used to tune the BioWin model for the Valrico Plant. The validation and optimization of the BioWin model with plant data was done by running a series of simulations and carrying out sensitivity analysis on the model which also allowed the development of operation policies and control strategies. The control strategies were developed for the key variables such as aeration requirements in the oxidation ditch, recycle rates and wastage flow rates. A controller that manipulates the wasting flow rate based on the amount of mixed liquor suspended solids (MLSS) was incorporated in the model. The objective of this controller was to retain about 4500-4600 mg/L of MLSS in the oxidation ditch as it is maintained by the Valrico Plant. The Valrico AWWTP recycles around 80% of their effluent and hence, the split ratios were adjusted accordingly in the model to recycle the desired amount. The effluent concentrations from the BioWin model for the parameters such as Total Nitrogen (TN), Ammonia, Nitrate, Nitrite, Total Kjeldahl Nitrogen (TKN) complied with the discharge limits which is usually less than 2 mg/L for all the parameters.

Nitrogen removal technologies can help dairy industries meet their nutrient management needs. This thesis investigated two separate treatment technologies for total ammonia nitrogen (TAN) removal: algae raceway ponds and aerated biofilm reactors. Six 1000- liter algae raceway ponds and four 1000-liter tote tanks, each equipped with 10 sheets of nonwoven geotextile (i.e., thermally bonded or needle-punched) biofilm substrate, were used to treat the effluent from a flush dairy in central coastal California (TAN = 251 mg/L, cBOD5 = 204 mg/L). For the algae raceway ponds (TAN loading rate = 7 - 35 g/m³-day among 7-, 10- and 14-day hydraulic residence times (HRT)), first-order removal rate constants (k) were ~0.2 day⁻¹ in the summer and 0.1 - 0.2 day⁻¹ in the winter. Removal rate constants had no correlations (R² < 0.1) with water temperature, weak to moderate (for 7-day ponds, R² = 0.55) correlations with insolation and weak to no correlations with biomass (i.e. volatile solids) concentration. During the winter, low insolation likely inhibited algal photosynthesis and biological TAN treatment. Ponds with 7-day HRT had distinct absence of nitrate and nitrite compared to 10- and 14-day ponds. Net productivities were ~20 g/m²-day in summer and 9 – 11 g/m²-day in winter; gross productivities were 120 – 160 g/m²-day in summer and 77 – 150 g/m²-day in winter. Productivities had no correlations (R² < 0.1) with water temperature and weak to moderate correlations (for 14-day ponds, net productivity R² = 0.56, gross productivity R² = 0.83) with insolation. Analysis of organic compounds in pond effluent showed dissolved volatile solids (~2300 mg/L) were mostly non-biodegradable (~98% of soluble oxygen demand). Dissolved organic nitrogen concentrations in the pond effluent were ~35 mg/L. For the aerated biofilm reactors, tanks with needle-punched geotextiles had greater first- order TAN removal rate constants (0.69 day⁻¹) than tanks with thermally bonded geotextiles (0.23 day⁻¹) while operating in batch mode. Needle-punched geotextile reactor also accumulated sludge faster and had higher attached to water column biomass (i.e. volatile solids) ratios (~0.08 g VS/g VS) than thermally bonded geotextile reactor (~0.04 g VS/g VS). Among the four tanks, mass of attached biomass was 150 – 340 g per tank while mass of biomass in the water column was 3290 – 5430 g per tank. Comparing the two treatment technologies, aerated biofilm reactors (removal = 64 – 77%, k = 0.2 – 0.3 day⁻¹, removal rate = 36 – 43 g-N/m²-day, 16 – 19 g-N/m³-day) had more removal and faster removal rates per square meter of land footprint compared to the algae raceway ponds (removal = 38 – 77%, k = 0.1 – 0.2 day⁻¹, removal rate = 4 – 5 g- N/m²-day, 13 – 17 g-N/m³-day), likely due to direct application of aerators in the reactors.

The aim of this master thesis study was improvement of the required operational conditions for aerobic granulation in sequencing batch reactors (SBRs). In the first part of the study, membrane bioreactor sludge (MBS) and conventional activated sludge (CAS), were used to investigate the effect of suspended seed sludge type on granulation in SBRs. The MBS granules were found to be advantageous in terms of size, resistance to toxic effects, stability and recovery compared to CAS granules. During non-inhibitory conditions, sCOD removal efficiencies were 70&plusmn / 13% and 67&plusmn / 11% for MBS and CAS, and total nitrogen (TN) removal efficiencies were 38&plusmn / 8% and 26&plusmn / 8%, respectively. In the second part of the study, the effects of period sequence (anoxic-aerobic and aerobic-anoxic) on aerobic granulation from MBS, and sCOD, N removal efficiencies were investigated. Granules developed in anoxic-aerobic period sequence were more stable and larger (1.8-3.5 mm) than granules developed in aerobic-anoxic sequence. Under steady conditions, almost 95% sCOD, 90% Total Ammonia Nitrogen (TAN) and around 39-47 % of TN removal was achieved. Almost 100% denitrification in anoxic period was achieved in anoxic-aerobic period sequence and it was observed around 40% in aerobic-anoxic period sequence. The effects of influent sulfate (from 35.1 mg/L to 70.2 mg/L) on treatment efficiencies of aerobic granules were also investigated. The influent SO42- concentrations of 52.6 mg/L to 70.2 mg/L promoted sulfate reduction. The produced sulfide (0.24 mg/L to 0.62 mg/L) inhibited the ammonia-oxidizing bacteria (AOB) performance by 10 to 50%.

Submitted by Neusa Fagundes (neusa.fagundes@unioeste.br) on 2017-09-06T13:24:19Z No. of bitstreams: 1 Adelcio_Giongo2016.pdf: 1383735 bytes, checksum: ddf849e35c040eb04a0c84af1eeb643f (MD5) / Made available in DSpace on 2017-09-06T13:24:19Z (GMT). No. of bitstreams: 1 Adelcio_Giongo2016.pdf: 1383735 bytes, checksum: ddf849e35c040eb04a0c84af1eeb643f (MD5) Previous issue date: 2017-07-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The swine industry has shown strong development and, thus, has produced large volumes of effluents that must be correctly managed. Therefore, when such effluent cannot be released into soil, a treatment must be carried out to avoid environmental impacts of swine wastewater. Nitrogen is one of the elements that takes part in swine waste and it must be under constant evaluation, but, in some cases, it must be removed. Nitrification/denitrification (NDF) process is a frequent applied technology. However, when the effluent presents low C/N ratio, such as effluents after anaerobic processes, there is some decrease on denitrification efficiency and the total nitrogen removal can be affected. In this case, Nitritation/denitritation (NDT) process can be used to improve the system performance as well as save energy cost with aeration and external source of carbon due to the lower C/N requirement. Thus, this study aimed at evaluating swine wastewater based on NDF and NDT processes at different C/N ratios in order to obtain a system with efficient nitrogen removal and low oxygen and carbon consumption. Four phases were carried out during this experiment: Phase I) DO from 2.0-3.0 mgO2L-1 to 1.5 C/N; Phase II) DO from 0.6-0.7 mgO2L-1 to 1.5 C/N; Phase III) DO from 0.6 to 0.7 mgO2L-1, different C/N ratios (1.5, 0.9, 0.75 and 0.6); Phase IV) DO from 2.0 to 3.0 mgO2L-1, different C/N ratios (1.5, 0.9, 0.75, and 0.6). The best operational condition was obtained at nitritation/denitritation process, whose C/N ratio was 0.9, and the optimum N removal was 86.3%. Under this condition, the system saved almost 36.8% of total organic carbon consumption and nearly 74% of dissolved oxygen consumed when compared to the conventional process for N-removal. This strategy can be very useful for nitrogen removal with low carbon rates, as the digestate from anaerobic processes. / A atividade suinocultura tem apresentado forte crescimento, e assim vem produzindo grandes volumes de efluentes que devem ser corretamente administrados. Portanto, quando não é possível a aplicação deste tipo de efluente no solo, o tratamento deve ser aplicado para que se evitem impactos ambientais. O nitrogênio é um dos elementos presentes nos dejetos de suínos que deve estar sob constante avaliação, e em alguns casos deve ser removido. O processo de nitrificação/desnitrificação (NDF) é uma tecnologia frequentemente aplicada, porém, quando o efluente apresenta baixa relação C/N, como efluentes pós-processos anaeróbios, a eficiência da desnitrificação é reduzida e a remoção de nitrogênio total pode ser afetada. Neste caso, o processo de nitritação/desnitritação (NDT) pode ser utilizado para melhorar o desempenho do sistema e economizar energia com aeração e com fonte externa de carbono, devido ao requisito de baixa relação C/N. Assim, o objetivo deste estudo foi avaliar a água residuária de suinocultura utilizando nitrificação/desnitrificação e nitritação/desnitritação em diferentes relações C/N, a fim de se obter um sistema com eficiente remoção de nitrogênio e baixo consumo de oxigênio e carbono. Quatro fases foram realizadas durante o experimento: Fase I) OD entre 2,0-3,0 mgO2 L-1 (nitrificação) e C/N 1,5; Fase II) OD entre 0,6-0,7 mgO2 L-1 (nitritação), e C/N 1,5; Fase III) OD entre 0,6-0,7 mgO2 L-1, diferentes relações C/N (1,5, 0,9, 0,75 e 0,6); Fase IV) OD entre 2,0-3,0 mgO2 L-1, diferentes relações de C/N (1,5, 0,9, 0,75 e 0,6). A melhor condição operacional foi encontrada no processo nitritação/desnitritação, com relação C/N de 0,9, cuja remoção de N considerada ótima foi de 86,3%. Nesta condição, a economia do sistema foi de 36,8% do consumo total de carbono orgânico e de cerca de 74% do consumo de oxigênio dissolvido, quando comparado com o processo convencional de remoção de N. Esta estratégia pode ser muito útil para a remoção do nitrogênio de efluentes de baixo teor de carbono, como os provenientes de processos anaeróbios.

A pilot scale nitrogen (N) removal system was constructed and operated for approximately 365 days and was designed to remove inorganic total ammonia nitrogen (TAN) from solids-separated dairy manure. An anaerobic fermenter, upstream of the N removal reactor, produced volatile fatty acids (VFAs), to be used as an electron donor to fuel denitrification, and TAN at a COD:N ratio of 18:1. However, sufficient amounts of non-VFA COD was produced by the fermenter to fuel the denitrification reaction at an average NO3- removal rate of 5.3 ± 2 mg/L NO₃--N. Total ammonia N was removed from the fermenter effluent in an N removal reactor where a series of aerobic and anoxic zones facilitated aerobic TAN oxidation and anoxic NO₃- and NO₂- reduction. The minimum dissolved oxygen (DO) concentration allowing for complete TAN removal was found to be 0.8 mg/L. However, TAN removal rates were less than predicted using default nitrifying kinetic parameters in BioWin®, a biological modeling simulator, which indicated the presence of a nitrification inhibitor in fermented dairy manure. Furthermore, an N balance during the aerobic zone indicated that simultaneous nitrification-denitrification (SND) was occurring in the aerobic zone of the N removal reactor and was most apparent at DO concentrations below 1.3 mg/L. A series of nitrite generation rate (NGR) experiments confirmed the presence of an inhibitor in fermented dairy manure. A model sensitivity analysis determined that the most sensitive ammonia oxidizing bacteria (AOB) kinetic parameters were the maximum specific growth rate, , and the substrate half saturation coefficient, . Nitrifying inhibition terms of competitive, non-competitive, mixed competitive, and un-competitive were applied to the growth rate equation in BioWin® but an accurate representation of the observed TAN removal rates in the pilot scale system could not be found by adjusting the kinetic parameters alone. Reducing the default BioWin® hydrolysis rate by approximately 50% produced a more accurate calibration for all inhibition terms tested indicating that the hydrolyization of organic N in dairy manure is less than typical municipal waste water. / Master of Science

Το Πι-κριτήριο των Bittanti et al. (1973) έχει χρησιμοποιηθεί εκτενώς σε εφαρμογές με στόχο την πρόβλεψη ενδεχόμενης βελτίωσης της απόδοσης ενός μη γραμμικού συστήματος υπό περιοδική είσοδο. Το κριτήριο όμως έχει τοπική ισχύ και περιορίζεται σε περιοδικές διαταραχές μικρού πλάτους. Η παρούσα εργασία αναπτύσσει μια μέθοδο προσδιορισμού διορθώσεων υψηλότερης τάξης στο πι-κριτήριο, προερχόμενη από βασικά αποτελέσματα της θεωρίας κεντρικής πολλαπλότητας (Center Manifold theory). Η προτεινόμενη μέθοδος βασίζεται στην επίλυση της μερικής διαφορικής εξίσωσης της κεντρικής πολλαπλότητας με χρήση δυναμοσειρών. Το τελικό αποτέλεσμα της προτεινόμενης προσέγγισης είναι ο κατά προσέγγιση υπολογισμός του δείκτη απόδοσης υπό μορφή σειράς, η οποία παρέχει ακριβή αποτελέσματα σε μεγαλύτερα εύρη. Η προτεινόμενη μέθοδος εφαρμόζεται σε έναν συνεχή αντιδραστήρα πλήρους ανάδευσης (CSTR), όπου στόχος είναι η μεγιστοποίηση της παραγωγής του επιθυμητού προϊόντος. Κατασκευάστηκε αλγόριθμος που προβλέπει την μόνιμη κατάσταση στην οποία καταλήγει ένα σύστημα απομάκρυνσης αζώτου που αποτελείται από αντιδραστήρα εμβολικής ροής και δεξαμενή δευτεροβάθμιας καθίζησης με ανακύκλωση. Με χρήση υπολογιστικού μοντέλου βασιζόμενο στο ASM3 υπολογίστηκαν οι μόνιμες καταστάσεις αυτού του συστήματος για ένα εύρος καταστάσεων λειτουργίας. Βρέθηκαν οι βέλτιστες τιμές των βαθμών ελευθερίας για την ελαχιστοποίηση του συνολικού αερισμού και για την ελαχιστοποίηση του συνολικού αζώτου στην απορροή. Και στις δύο περιπτώσεις στις βέλτιστες μόνιμες καταστάσεις παρατηρήθηκε έκπλυση των Nitrobacter δηλαδή παράκαμψη της παραγωγής των νιτρικών. / The frequency-dependent Pi criterion of Bittanti et al. (1973) has been used extensively in applications to predict potential performance improvement under periodic forcing in a nonlinear system. The criterion, however, is local in nature and is limited to periodic forcing functions of small magnitude. The present work develops a method to determine higher-order corrections to the pi criterion, derived from basic results of Center Manifold theory. The proposed method is based on solving the Center Manifold partial differential equation via power series. The end result of the proposed approach is the approximate calculation of the performance index in the form of a series expansion, which provides accurate results under larger amplitudes. The proposed method is applied to a continuous stirred tank reactor, where the yield of the desired product must be maximized. An algorithm was constructed, that predicts the steady state of a nitrogen removal system consisting of a plug flow reactor and a secondary clarifier with recycle. Using a numerical model based on ASM3 and a grid of degrees of freedom, the steady states of this system were calculated. The optimal values for minimizing the total aeration were found, as well as those for minimizing the total nitrogen exit flow. In both cases the Nitrobacter bacteria were washed out thus indicating the bypassing of nitrate production.

Les sédiments sont des sites importants d’élimination d’azote (N) puisqu’ils possèdent des gradients d’oxydoréduction leur conférant les conditions idéales pour les réactions microbiennes de transformation de N. L’eutrophisation des régions côtières peut altérer ces gradients, par des changements dans la concentration d’oxygène (O2) de l’eau interstitielle, et modifier l’importance relative des processus transformant le N. Afin de mieux comprendre comment l’O2 pourrait influencer les transformations de N, nous avons mesuré les flux diffusifs de diazote (N2), nitrate (NO3-), oxygène et ammonium (NH4+) dans les sédiments de l’Estuaire Maritime du St-Laurent (EMSL), et nous avons estimé les taux de dénitrification. L’importance du couple nitrification-dénitrification en fonction d’un gradient de concentrations d’O2 dans la zone d’hypoxie de l’EMSL fut aussi évaluée. La concentration des gaz dissous fut mesurée en utilisant une nouvelle approche développée dans cette étude. Les flux diffusifs de N2, O2, NO3- et NH4+ variaient de 5.5 à 8.8, de -37.1 à -84.8, de -4.0 à -5.8 et de 0.6 à 0.8 μmol N m-2 h-1 respectivement. Les concentrations de N2 et NO3- dans l’eau porale et les flux de NO3- et de N2 des sédiments, suggèrent que la diffusion de NO3- provenant de l’eau à la surface des sédiments ne peut pas expliquer par elle-même la production de N2 observée. En utilisant une approche stoichiométrique, les taux de nitrification potentielle estimés comptent pour 0.01 à 52% du flux total de NO3 nécessaire pour aboutir aux flux de N2 observés et diminuent avec l’augmentation de l’hypoxie. / Sediments display strong redox gradients and represent important sites of various microbially mediated nitrogen (N) transformation pathways resulting in the loss of fixed N. Increased eutrophication of coastal systems will likely impact the overall function of these sediments via changes in the oxygen (O2) concentration in the overlying water, thus influencing the redox gradient and the relative importance of different N processes. To have a better understanding of how O2 could influence N transformations, we measured dinitrogen (N2), nitrate (NO3-), oxygen and ammonium (NH4+) diffusive fluxes in the sediments of the Lower St. Lawrence Estuary (LSLE) and estimated denitrification rates. The importance of the nitrification-denitrification couple as a function of a gradient of hypoxic O2 concentrations was also evaluated. Dissolved gas concentrations were measured using a new approach developed in this study. N2, O2, NO3- and NH4+ diffusive fluxes varied respectively from 5.5 to 8.8, from -37.1 to -84.8, from -4 to -5.8 and from 0.6 to 0.8 μmol N m-2 h-1 among the five stations sampled. N2 and NO3- concentrations in sediment pore water and measured fluxes of NO3- in and N2 out of the sediments suggested that NO3- diffusion from the overlying water alone could not support N2 production. Using a stoichiometric approach, estimated potential nitrification rates varied among sites, from 0.01 to 52% of the total NO3 supply rate. The relative importance of nitrification decreased with increasing hypoxia.

No description available.

Made available in DSpace on 2014-12-17T15:03:27Z (GMT). No. of bitstreams: 1 WelitonFBF_DISSERT.pdf: 2010897 bytes, checksum: 9145c54f00922f08967d3beb644f5f73 (MD5) Previous issue date: 2011-07-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The improper disposal of nitrogen in receiving water courses causes problems such as toxicity to living beings through the consumption of oxygen to meet the nitrogen demand, eutrophication and nitrate contamination of aquifers. For this reason it is often necessary to be carried out complementary treatment of wastewater to eliminate or reduce the concentration of this compound in the wastewater. The objective of this study is to evaluate the biological removal of nitrogen compounds using submerged aerated and anoxic filters as post-treatment of an anaerobic system, with low cost and innovative technology, which in previous studies has shown high removal efficiency of organic matter and great potential biological nitrogen compounds removal. The simple design with perforated hoses for air distribution and filling with plastic parts proved to be very efficient in relation to organic matter removal and nitrification. The system presented, in the best stage, efficiency in converting ammonia to nitrate by 71%, and produced a final effluent concentration below 10 mg / L of NH3-N. In addition, carbon concentration was removed by 77%, producing final effluent with 24 mg/L COD. However, denitrification in anoxic filter was not effective even with the addition of an external carbon source. There was a reduction of up to 56% of nitrogen caused by the process of simultaneous nitrification and denitrification (SND). The high voids space presented by this type of support material coupled with direct aeration of the sludge, allows the respiration of biomass retained between the endogenous phase, increased cell retention time and sludge retention capacity, producing a final effluent with turbidity less than 5 UT and total suspended solids around 5.0 mg/L / A disposi??o inadequada do nitrog?nio em corpos receptores gera problemas como: toxicidade para seres vivos; consumo de oxig?nio do meio para atender a demanda nitrogenada; eutrofiza??o; e contamina??o dos aqu?feros por nitrato. Por esta raz?o ? muitas vezes necess?rio que seja realizado tratamento complementar dos esgotos para eliminar, ou reduzir, a concentra??o deste composto nas ?guas residu?rias. O objetivo deste trabalho ? avaliar a remo??o biol?gica dos compostos nitrogenados utilizando filtros aerados submersos como p?s-tratamento de um sistema anaer?bio, com tecnologia inovadora, de baixo custo, que em estudos anteriores demonstrou grande efici?ncia na remo??o de mat?ria org?nica carbon?cea e grande potencial na remo??o biol?gica de compostos nitrogenados. A forma simples como o sistema foi concebido, com mangueiras perfuradas para distribui??o do ar e preenchimento com pe?as pl?sticas - condu?te cortado - mostrou-se bastante eficiente em rela??o ? remo??o de mat?ria org?nica e na nitrifica??o. O sistema apresentou, na melhor fase, efici?ncia na convers?o de nitrog?nio amoniacal em nitrato de 71%, e produziu efluente final com concentra??o de N-NH3 inferior a 10 mg/L. Al?m disso, observou-se uma redu??o de 77% na concentra??o de carbono, produzindo efluente final com 24 mg/L de DQO. Contudo a desnitrifica??o no filtro an?xico n?o se mostrou eficiente mesmo com a adi??o de uma fonte externa de carbono. Mesmo assim observou-se redu??o de at? 56% do nitrog?nio causado pelo processo de Nitrifica??o e Desnitrifica??o Simult?neas (SND). O grande ?ndice de vazios apresentado por este tipo de material suporte aliado ? aera??o direta do lodo, permite que a respira??o da biomassa retida entre na fase end?gena, aumentado o tempo de reten??o celular e a capacidade de reten??o de lodo, produzindo um efluente final com turbidez inferior a 5 UT e SST em torno de 5,0 mg/L