Settling properties of activated sludge or mixed liquor suspended solids (MLSS) have been studied for more than 75 years at wastewater treatment plants. Temperature, together with MLSS concentration, has been acknowledged as important contributors to MLSS settling variations. Batch MLSS settling tests are performed on a regular basis at most of the plants. The majority of these MLSS settling test reports reflect the complete absence of any form of temperature compensation or even MLSS sample temperature (Ts) recordings. The objective of this study is to evaluate the effects of short-term temperature variations on MLSS settling parameters. This is done by means of simplified theoretical calculations, followed by operational reactor temperature (Tr) observations, and batch MLSS settling tests. The experimental work concludes with the implementation of an on-line MLSS settling test procedure at a full-scale plant reactor to develop settling models based on diurnal Tr fluctuations. These settling models illustrate that parameter correlations improve when Tr is included in on-line MLSS concentration-based settling models. The unhindered settling velocity of a single solid biofloc in water is considered in a simplified calculation to estimate the effect of temperature variations on MLSS settling. Over a Ts increase of 20°C, water density and viscosity reductions result in a calculated biofloc settling velocity increase of less than 0.5 m/hr. Similarly, biofloc density, shape, and size changes result in calculated biofloc settling velocity increases of about 11, 10, and 2 m/hr respectively over the 20°C Ts range. Plant temperature recordings show significant short- to long-term variations. Ambient temperature (Ta) and Tr fluctuate about 20°C and 1.8°C respectively per day, and Tr changes by about 4°C within a week, as measured on-line at local plants during the test period in winter. The aeration method can have a significant impact on Tr. Differences in Tr in adjacent surface and bubble aeration reactors in the same plant were about 5°C. Large enough Tr and Ta variations exist at these local plants to affect MLSS settling test results. The MLSS settling test cylinder environment and meteorological conditions have a direct influence on Ts during batch settling tests. Direct solar radiation increases the average Ts by 4.3°C, or by 0.15°C per minute, during a 30-minute MLSS settling test duration. This Ts change leads to a sludge volume index (SVI) change of 63 mℓ/g, at an average SVI decrease of 14.8 mℓ/g per 1°C Ts increase. Changes to other parameters include an initial settling velocity (ISV) increase of about 0.12 m/hr for every 1°C Ts increase, together with a clarified supernatant turbidity increase of about 1.4 formazine nephelometric unit (FNU) for every 1°C Ts increase. Ts adjusts towards Ta before and during a batch MLSS settling test, thereby influencing MLSS settling results. Compensation for Ts variations during routine MLSS settling tests is nevertheless not reported as a common practice. To some extent, this is due to a lack of temperature-controlled MLSS settling test equipment. An automated MLSS settling meter demonstrates a semi-continuous on-line method to determine settling parameters in situ at the operational Tr of a full-scale plant. A basic polynomial fits 11 MLSS settling parameters that indicate in most instances improved MLSS settling at increased Tr. The average SVI decreases by 14.8 mℓ/g for every 1°C Tr increase. Similarly, for every 1°C Tr increase, the maximum settling velocity (u_max) increase is 0.1 m/hr, and the time to reach maximum settling velocity (t_umax) decreases by 2.4 minutes. The incremental 5-minute duration average settling velocities increase over the first 15 minutes of a MLSS settling test, as the MLSS concentration decreases and the Tr increases. This direct incremental settling velocity trend with Tr is reversed between 15 and 30 minutes, as the average 5-minute MLSS settling velocity increases at a reduced Tr. The inclusion of Tr in MLSS concentration-based settling best-fit correlations with SVI, u_max, and t_umax improves the coefficient of multiple determinations (R2) by an average of 0.32. Best-fit SVI models with u_max and t_umax have R2-values of 0.90 and 0.95 respectively. The developed models are only valid for the individual reactor MLSS conditions within the experimental parameter ranges. The main contribution of this study is to present temperature-based MLSS settling models. These models illustrate that an automated on-line MLSS settling meter is suitable to identify and model temperature related MLSS settling data with minimal experimental effort. A suitable approach is provided to improve the reliability of MLSS settling data, as effects of short-term temperature variations can be practically eliminated from settling test. / Thesis (PhD)--University of Pretoria, 2008. / Chemical Engineering / unrestricted

The activated sludge process comprises a complex and enriched culture of a mixture of generalist and specialist organisms. The lack of knowledge on species diversity of microbial communities is due to the simplicity of bacterial morphology and the phenotypic characters, and the unculturable portion of microbial cells in natural habitats. Although a wide range of bacteria can be isolated using conventional microbiological techniques of sample dilution and spread plate inoculation, many well-known activated sludge bacteria can not be isolated using them. The individual microbial cells in activated sludge grow in aggregates that consist of floc-forming organisms together with filamentous microorganisms that form the backbone of the activated sludge floes. Overgrowth of these filamentous microorganisms often causes settling problems called bulking and foaming. These problems consist of slow settling, poor compaction of solids and foam overflow into the effluent. Although methods for the isolation of filamentous bacteria from mixed liquor samples have been investigated, the attempts have been largely unsuccessful. In this study we investigated bulking and foaming activated sludge to identify the dominant filamentous organisms using microscopy and molecular techniques. Using microscopy, the dominant filament associated with the foaming sample was "Microthrix parvicella" and in the bulking sample was Nocardia spp. The foaming sample was investigated using molecular techniques that involved 165 rDNA sequencing. Although some of the clones isolated from the sludge foam were associated with filamentous bacteria causing foam, no positive identification could be made. In the part of the study that was conducted in Australia, a rRNA-targeted oligonucleotide probe was designed for the identification of a filamentous organism occurring in activated sludge foam. This organism resembled Eikelboom Type 0041 and was classified in the candidate bacterial division TM7. The discrepancy that the sequence data did not indicate the dominant filamentous organisms observed by microscopy, highlights the fact that natural microbial communities need to be studied using a combination of techniques since none of the techniques available are sufficient to determine the complete community structure of complex communities such as activated sludge. / Dissertation (MSc (Microbiology))--University of Pretoria, 2005. / Microbiology and Plant Pathology / unrestricted

The discharge of point- and non-point source pollutants into surface waters resulting from industrial and/or municipal activities is a major focus of environmental regulation in the United States. As a result, the National Pollutant Discharge Elimination System (NPDES) permit program was established in 1972 in an effort to regulate discharges from industrial or municipal sources, including wastewater treatment plants (WWTP). To further protect Florida water quality, in 1978, State legislation enacted the Grizzle-Figg Act for Tampa Bay, which requires advanced wastewater treatment for any discharge into sensitive water bodies. A common use of wastewater effluent in the Tampa Bay area is for reclaimed water for irrigation. This leads to an estimated 90% reduction of total nitrogen (TN) load to the bay in comparison to direct discharge (TBEP, 2016). One type of wastewater treatment process that has been shown to have low aeration and chemical requirements is simultaneous nitrification denitrification (SND), which can be carried out in an oxidation ditch. SND is a biological process for nitrogen removal where nitrification and denitrification occur at the same time within the same reactor. An oxidation ditch is a race-track type reactor that promotes the occurrence biological conversion of reactive nitrogen to nitrogen gas (N2) and additionally can provide enhanced biological phosphorus removal (EBPR). Many theories exist as to the mechanisms that allow SND to occur, but the literature is inconclusive as to whether the presence of different zones within the floc, within the reactor itself, a combination of the two or unique microorganisms are responsible for SND. Advantages of SND include efficient (80-96%) nitrogen removal, with significant reductions in energy, chemical, equipment and spatial requirements. Specifically, oxygen requirements are reduced and dedicated aerobic/anoxic zones, internal recirculation and supplemental carbon and alkalinity are not required. Despite these advantages, widespread use of SND is limited because of a lack of understanding of SND kinetics as well as interactions between factors affecting SND performance. This research was carried out at the Falkenburg Advanced Wastewater Treatment Plant (AWWTP) in Hillsborough County Florida, which carries out SND, biological and chemical phosphorous removal in an oxidation ditch system. Although this facility continually meets and exceeds its permit requirements, improvements in process control strategies have the potential to improve energy efficiency, as well as decrease chemical use, sludge production, greenhouse gasses (GHG) emissions and costs. Therefore, the overall goal of this research was to investigate mechanisms of nitrogen and phosphorus removal at the Falkenburg AWWTP. These goals were achieved through bench scale SND studies carried out at varying temperatures. Kinetic parameters were determined using a simple kinetic model of nitrification/denitrification. Additionally, carrying out sampling campaigns completed the investigation of the fate of phosphorus in the Falkenburg AWWTP. The results were combined with information on alum dosing and sludge wasting to determine the overall fate of phosphorus in the system and make additional recommendations regarding the addition of alum. To mimic an oxidation ditch at Falkenburg AWWTP, bench scale bioreactor experiments were set up in glass beakers at 22°C and 29.5 C. Influent wastewater and return activated sludge (RAS) for these experiments were collected from the Falkenburg AWWTP. Bioreactors were constantly mixed and aeration was controlled to maintain a target dissolved oxygen (DO) concentration based on measurements of DO at the facility. Three phosphorous sampling campaigns (October, November and December) were also carried out to understand the fate of phosphorous, nitrogen and organic carbon at the facility. In these campaigns, samples were taken at six locations at Falkenburg AWWTP and samples were analyzed for filtered and unfiltered total phosphorus, orthophosphate and polyphosphates, filtered and unfiltered total nitrogen, soluble, total and readily biodegradable COD (rbCOD), volatile acids, cations, anions, alkalinity, total suspended solids (TSS) and volatile suspended solids (VSS). pH and DO were also measured on site. In the nitrification batch reactors, in four hours, 50% of ammonia was successfully removed at a rate of 6.31 mg-N/L/hr indicating that four hours is not sufficient time to achieve complete removal. In the denitrification batch reactors, in six hours, there was successful removal of nitrate and nitrite at a rate of 23.70 mg-NO3-/L/hr and 3.6 mg-NO2-/L/hr. In an SND batch reactor experiments at 22° C, ammonia oxidation successfully occurred in 12 hours but denitrification was inhibited due to insufficient rbCOD in the reactor. In an SND batch reactor at 29.5° C, no accumulation of nitrate or nitrite was observed, indicating successful SND. At a higher temperature, sludge bulking occurred in the reactor resulting in variations in TSS and VSS concentrations. Results from the sampling campaigns at the treatment plant indicate that successful phosphorus removal was achieved. Alum addition varied before each sampling and a relationship between alum addition and sulfate can be made. rbCOD was consumed throughout the treatment process as expected and noticeable results can be noted when rbCOD was low in terms of phosphorus removal. The results of the bench-scale experiments showed that the SND was successfully achieved at the Falkenburg facility and that temperature, DO and rbCOD are all important factors controlling biological nutrient removal at SND facilities. DO is much more difficult to maintain and control at a higher temperature further supporting the idea that stricter operator control is needed in warmer months. Additionally, because SND removal still occurred with poor DO control at 29.5°C, it further supports the idea that SND occurs because of zones within the floc, the reactor or that novel microorganisms exist that allow denitrification to occur above ideal DO concentration and nitrification to occur below ideal concentrations of DO. A variation in rbCOD in the influent wastewater at the treatment plant caused nitrification and denitrification to be inhibited in different trials. With too much rbCOD, nitrification was inhibited and with too little rbCOD, denitrification was inhibited. Additionally, alkalinity consumption was minimal which supports the idea that supplemental alkalinity is not needed in SND processes. The results from the phosphorous sampling campaign show how important influent COD is for successful phosphorus removal in the system. The objectives were achieved and overall, the plant is achieving SND and EBPR and the plant is performing as designed. The addition of alum should continue to be studied to determine a better dose and save the county ratepayers money while still meeting permit regulations. Jar tests should be used to determine the proper dosing that will not hinder the settling properties further in the treatment train. Additionally, alum feed pipe sizes should be investigated at the plant to ensure no clogging occurs with a decrease in alum flow and automated aeration based on ammonia concentrations should be considered to remove the manual operation of aerators.

Les lits de séchage de boues plantés de roseaux (LSPR) existent en France depuis le début des années 1990. Ceux-ci ont principalement été développés pour le traitement de boues issues de station boues activées en aération prolongée. Cependant, ce procédé est trop souvent associé à des problèmes de dysfonctionnements liés à des dimensionnements et des gestions mal maîtrisés. En effet, les installations souvent composées de 4 lits souffrent de performances insuffisantes avec une siccité qui avoisine seulement 15 % contre 30, voire 35 % au Danemark où la technique est largement répandue. Une meilleure connaissance des divers mécanismes en jeux contribuerait sans conteste à accroître les potentialités de cette filière. En outre, avec la mise en place croissante de SPANC, l'augmentation future du flux de matières de vidange à traiter nous a également amené à transposer ce procédé vers ce type de produit. Pour cela le suivi de 16 pilotes de 2 m² en phase de démarrage et d'une installation de taille réelle de type « boues activées en aération prolongée » (13 000 EH, 8 lits de 470m² en fonctionnement depuis 4 ans) a permis d'étudier l'influence de différentes qualités de boues (boues activées épaissies ou non, matières de vidange), de la charge organique, et de la fréquence d'alimentation sur les performances de déshydratation et de minéralisation. Après un an et demi de phase de démarrage, ce travail de thèse se focalise sur le fonctionnement au nominale du système. Les expérimentations menées sur les pilotes ont permis d'identifier les limites du système, et ainsi émettre des préconisations de dimensionnement et de gestion pour chacun des deux types de boue étudiés. Parallèlement, des expériences menées en laboratoire ont permis de d'étudier plus finement les phénomènes en cause. Notamment en répondant aux questions relatives à l'influence de la qualité de la boue. De plus, une étude mécaniste a également été menée pour identifier l'influence du drainage et de l'évapotranspiration des roseaux sur la déshydratation des boues. Enfin, les processus impliqués dans la stabilisation des boues ont également été étudiés. / Sludge drying reed beds exist in France since the early 1990s and have been mainly developed for activated sludge treatment. Nevertheless, these systems often operate badly due to unadapted design and management strategy. The usual design for these facilities consists of 4 beds each being alternately fed during a week. Performances are low with a dryness around only 15% against 30 or 35% in Denmark where this technology is widespread. A better knowledge of the mechanisms will indisputably increase the potentiality of this process. Besides, taking into account the obligation of regulatory control of on-site wastewater treatment, communities are now facing larger volumes of septage. Therefore, one of the main idea of this study is to also use drying reed beds for septage treatment. Thus, 16 pilots of 2m² each and a full–scale plant (13 000 p.e., 8 beds of 470m² in operation for 4 years) have been monitored to study the influence of the sludge quality (activated sludge thickened or not, septage and a mixture of both), the sludge loading rate, and the load frequency on the dewatering and mineralization efficiencies. After one and a half year of commissioning period, this thesis focuses on the nominal operating conditions. Experiments carried out on pilots allow the limits of the system to be identifying. Hence, design and management recommendations for both types of sludge studied can be established. Meanwhile, laboratory experiments have aimed at evaluating more precisely the phenomena involved in the system. We first consider the influence of the sludge quality on its treatment ability on sludge drying reed beds. In addition, a mechanistic study was also conducted to identify the influence of drainage and reeds evapotranspiration on the sludge dewatering. Finally, the processes involved in the sludge stabilization were also investigated.

Submitted in fulfilment of the requirements of the degree of Master of Technology: Biotechnology, Durban University of Technology, Durban, South Africa, 2014. / Wastewater treatment plants (WWTPs) frequently experience bulking and foaming episodes, which present operational challenges by affecting sludge settling due to the excessive proliferation of filamentous bacteria. Various control strategies have been implemented over the years to minimize filamentous growth, however, filamentous bulking still remains an unresolved problem in many WWTPs worldwide. The current study focused on developing and optimizing remedial measures viz., specific and non-specific methods to reduce problematic filamentous bacteria in a full-scale WWTP. Specific methods demonstrated the influence of plant operational parameters viz. chemical oxygen demand, influent N-NH4+, food to microorganism ratio, dissolved oxygen, temperature and pH on the abundance of filamentous bacteria. A cumulative logit model was used to determine the significant relationships between the individual filamentous bacteria at present and the prevailing plant operational parameters. Using the above statistical approach, significant observations and predictions were made with respect to the individual filamentous growth under certain operational parameters. With further validation, this model could be successfully applied to other full-scale WWTPs identifying specific parameters that could contribute to filamentous bulking, thus providing a useful guide for regulating specific filamentous growth. Non-specific control methods such as chlorine, ultraviolet irradiation and ozone treatment were investigated on filamentous bacteria using a live/dead staining technique. To achieve at least 50% reduction of filamentous bacteria, a chlorine dose of 10 mg Cl2/L was required, all filaments were killed at a dose of 22 mg Cl2/L. In addition, an effective UV and ozone dose of 4418.91 μw seconds/cm2 and ±20 mg O3/L respectively, was required to kill 50% of the filamentous bacterial population. Among the three non-specific methods, ozone treatment seemed to be an effective method in controlling the filamentous population with a low negative impact to the surrounding environment. This study serves as a useful guide on the problems and control of filamentous bulking in activated sludge plants. / M

Made available in DSpace on 2016-01-26T18:56:02Z (GMT). No. of bitstreams: 1 Murilo Mendes de Angelo.pdf: 1443900 bytes, checksum: f6d656f910c3210fd63e015a55ec60a4 (MD5) Previous issue date: 2014-11-28 / The Agriculture in the Pontal do Paranapanema region is a major source of employment and income, with the highlight the cultivation of sugar cane. Along with the expansion of the cultivated area has been a substantial increase in the use of herbicides. Among the various existing herbicides in the domestic market, glyphosate, Roundup®, appears with great relevance in the agricultural scenario, because in addition to efficient has a broad spectrum of action. Moreover, their use also generates unwanted environmental impacts, such as changes in soil microbes and the generation of a taproot. Additionally, by leaching a part of glyphosate applied to crops can reach surface water, such as rivers. In the face of this problem, this study followed the process of degradation of glyphosate in a biological reactor, through the activated sludge process. Two studies, the first of which used a synthetic wastewater containing glyphosate as a source of carbon, nitrogen and phosphorus and sewage sludge. The second treatment was done under the same conditions first by adding a hydrogel polymer. These polymers are employed in the sugarcane plantations for water retention and can reach surface waters through leaching. The monitoring system was conducted through analysis of chemical oxygen demand (COD), amount of phosphorus, nitrogen, glyphosate, nitrite and nitrate, reaction temperature, pH and Dissolved Oxygen. The results demonstrate that the treatment of the effluent containing only glyphosate is more efficient than treatment containing glyphosate and the hydrogel polymer. / A agricultura na região do Pontal do Paranapanema é uma das principais fontes de emprego e de renda, tendo como destaque o cultivo da cana de açúcar. Junto com a expansão da área cultivada tem ocorrido um aumento substancial na utilização de herbicidas. Dentre os vários herbicidas existentes no mercado nacional, o glifosato, Roundup®, aparece com grande relevância no cenário agrícola, pois além de eficiente possui um amplo espectro de ação. Por outro lado, a sua utilização também acaba gerando impactos ambientais indesejados, como a alteração na microbiota do solo e a geração da raiz pivotante. Adicionalmente, através da lixiviação, uma parte do glifosato aplicado nas lavouras pode atingir as águas superficiais, como por exemplo a dos rios. Em face deste problema, o presente trabalho acompanhou o processo de degradação do glifosato, em um reator biológico, por meio do processo de lodos ativados. Dois estudos foram realizados, sendo que o primeiro utilizou um efluente sintético contendo glifosato como fonte de carbono, nitrogênio e fósforo e o lodo de esgoto. O segundo tratamento foi realizado sob as mesmas condições do primeiro, adicionando-se um polímero hidroabsorvente. Estes polímeros são empregados nas plantações canavieiras para a retenção da água e também podem atingir as águas superficiais, através da lixiviação. O monitoramento do sistema foi realizado através das análises da demanda química de oxigênio (DQO), quantidade de fósforo, de nitrogênio, do glifosato, do nitrito e do nitrato, temperatura do reator, pH e Oxigênio Dissolvido. Os resultados demostraram que o tratamento do efluente contendo apenas o glifosato é mais eficiente do que o tratamento contendo o glifosato e o polímero hidroabsorvente.

Made available in DSpace on 2016-07-18T17:46:20Z (GMT). No. of bitstreams: 1 Murilo Mendes de Angelo.pdf: 1443900 bytes, checksum: f6d656f910c3210fd63e015a55ec60a4 (MD5) Previous issue date: 2014-11-28 / The Agriculture in the Pontal do Paranapanema region is a major source of employment and income, with the highlight the cultivation of sugar cane. Along with the expansion of the cultivated area has been a substantial increase in the use of herbicides. Among the various existing herbicides in the domestic market, glyphosate, Roundup®, appears with great relevance in the agricultural scenario, because in addition to efficient has a broad spectrum of action. Moreover, their use also generates unwanted environmental impacts, such as changes in soil microbes and the generation of a taproot. Additionally, by leaching a part of glyphosate applied to crops can reach surface water, such as rivers. In the face of this problem, this study followed the process of degradation of glyphosate in a biological reactor, through the activated sludge process. Two studies, the first of which used a synthetic wastewater containing glyphosate as a source of carbon, nitrogen and phosphorus and sewage sludge. The second treatment was done under the same conditions first by adding a hydrogel polymer. These polymers are employed in the sugarcane plantations for water retention and can reach surface waters through leaching. The monitoring system was conducted through analysis of chemical oxygen demand (COD), amount of phosphorus, nitrogen, glyphosate, nitrite and nitrate, reaction temperature, pH and Dissolved Oxygen. The results demonstrate that the treatment of the effluent containing only glyphosate is more efficient than treatment containing glyphosate and the hydrogel polymer. / A agricultura na região do Pontal do Paranapanema é uma das principais fontes de emprego e de renda, tendo como destaque o cultivo da cana de açúcar. Junto com a expansão da área cultivada tem ocorrido um aumento substancial na utilização de herbicidas. Dentre os vários herbicidas existentes no mercado nacional, o glifosato, Roundup®, aparece com grande relevância no cenário agrícola, pois além de eficiente possui um amplo espectro de ação. Por outro lado, a sua utilização também acaba gerando impactos ambientais indesejados, como a alteração na microbiota do solo e a geração da raiz pivotante. Adicionalmente, através da lixiviação, uma parte do glifosato aplicado nas lavouras pode atingir as águas superficiais, como por exemplo a dos rios. Em face deste problema, o presente trabalho acompanhou o processo de degradação do glifosato, em um reator biológico, por meio do processo de lodos ativados. Dois estudos foram realizados, sendo que o primeiro utilizou um efluente sintético contendo glifosato como fonte de carbono, nitrogênio e fósforo e o lodo de esgoto. O segundo tratamento foi realizado sob as mesmas condições do primeiro, adicionando-se um polímero hidroabsorvente. Estes polímeros são empregados nas plantações canavieiras para a retenção da água e também podem atingir as águas superficiais, através da lixiviação. O monitoramento do sistema foi realizado através das análises da demanda química de oxigênio (DQO), quantidade de fósforo, de nitrogênio, do glifosato, do nitrito e do nitrato, temperatura do reator, pH e Oxigênio Dissolvido. Os resultados demostraram que o tratamento do efluente contendo apenas o glifosato é mais eficiente do que o tratamento contendo o glifosato e o polímero hidroabsorvente.

O tratamento de esgotos municipais através de reatores do tipo \"Up-flow Anaerobic Slugde Blanket\" - UASB, já são utilizados há vários anos em alguns estados do Brasil. Seu rendimento no tratamento está na faixa de 65 a 75% de remoção de carga orgânica medida em DBO, necessitando portanto de um pós - tratamento, por exemplo AERÓBIO, como Filtros Biológicos Percoladores, Filtros Biológicos submersos Aerados, Lodos Ativados etc. Devido a evolução da legislação e dos sistemas de tratamento no nível terciário, ou seja, remoção de nutrientes, estes pós - tratamentos se fazem ainda mais necessários para remoção de nitrogênio amoniacal por exemplo, com remoção completa usando de nitrificação e denitrificação ou simplesmente atingindo o estágio de nitrificação, pois o nitrogênio amoniacal é tóxico para uma boa parcela da vida aquática, peixes principalmente, enquanto o nitrogênio na forma do íon nitrato ou nitrito é considerado menos tóxico. Já existe na literatura algumas descrições de como dimensionar tais unidades de pós - tratamento, todavia, os parâmetros usados são teóricos e baseados nos já existentes para esgotos sanitários tipicamente domésticos, não havendo ainda uma fonte de dados experimentais para tais parâmetros. O intuito deste trabalho foi o de obter dados mais reais para projeto de pós - tratamento de efluentes de reatores UASB, usando o equacionamento e os métodos apresentados por Ekama, Dold e Marais (1986), baseado num sistema piloto de Lodos Ativados, em escala de laboratório, alimentado com efluente de um reator UASB instalado no campus da USP, mais precisamente no Centro Tecnológico de Hidráulica (CTH) da Escola Politécnica. Este reator trata o esgoto gerado no restaurante comunitário e apartamentos de moradia dos alunos (CRUSP), da Universidade. Como todos os sistemas biológicos aeróbios de tratamento se baseiam nas mesmas frações, os dados aqui obtidos são úteis para qualquer outro pós - tratamento aeróbio destes efluentes. As frações obtidas foram: fup = 0,15, frb ~0 e fus= 0,2. / The treatment of municipal wastewaters through \"Up-flow Anaerobic with Sludge Blanket\" - UASB reactors -, are already used for many years in some states of Brazil. It\'s output in the treatment is in the range of 65% to 75% of organic load remove in BOD, needing so an after-treatment, for example the AEROBIC, like Percolator Biologic Filters, aerated submerse Biological Filters, Activated Sludge etc. Due to the evolution of legislation and treatment systems in the tertiary level, that means, nutrients remove, these after-treatments are even more necessary to the removal of ammonia nitrogen for example, with complete removal using nitrification and denitrification or simply achieving the nitrification stage, because the ammonia is toxic to a great part of aquatic life, mostly fishes, while the nitrogen in the form of ions nitrate or nitrite is considered less toxic. There are already in the literature some descriptions of how to dimension those units of after-treatment, however, the parameters used are theoretical and based on the pre-existent to sanitary wastewater typically domestic, not having yet a source of experimental data for those parameters. The objective of this paper is to get real data to project the after- treatment of effluents of UASB reactors, using the equation and the methods presented by Ekama, Dold e Marais (1986), based in a pilot system of Activated Sludge, in laboratory level, fed with effluent of an UASB reactor installed on the campus of USP, more precisely in the Hydraulic Technological Center (CTH). This reactor treats the wastewater generated in the communitary restaurant and apartments where the University students live (CRUSP). Like all the aerobic biologic systems of treatment base themselves in the same fractions, the collected data here are really useful to any other aerobic after-treatment of these effluents. The fractions obtained were: fup = 0,15, frb ~0 and fus= 0,2.

The objective of this study was to investigate the anaerobic biological treatment of an organic-bearing wastewater from a particular paper manufacturing process at laboratory scale. The process produces paper by re-pulping waste paper. Effluent from the process has a Chemical Oxygen Demand (COD) concentration of approximately 4500 mg/l with a sulphate content of approximately 300 mg SO₄²⁻/l. The upflow anaerobic sludge bed (UASB) reactor was selected for the study. Important information derived from the laboratory treatability study was: (l) the extent of COD removal possible; (2) the effluent quality; (3) the maximum COD leading rate (kgCOD/m³ reactor/day) which can be achieved while maintaining reasonable COD removal, and the influence on loading rate of temperature: (4) the nature of the sludge produced in the reactor with particular reference to the extent of pelletisation: and (5) the effect of reactor effluent recycling on alkalinity requirements.

The treatment of water for human consumption results in the production of residual waste flows that vary depending on source waters and water treatment technologies. Water treatment plant residual waste is defined as a pollutant that requires treatment either on site or through other means. Due to strict and evolving regulatory requirements, treatment of water treatment plant residual waste several common methods of disposing of water plant residuals exist including discharge to surface waters, discharge to sanitary sewers, and sanitary landfill disposal of dewatered wastes. Although originally discharged to the neighboring City Reservoir, the Carbondale Water Treatment Plant (CWTP) conducted an initial study to determine if plant residual waste could be treated at one of the City’s two wastewater treatment plants. No negative impacts were identified as part of this study and infrastructure was put in place to divert CWTP residual waste from the City Reservoir to the Carbondale Southeast Wastewater Treatment Plant (SEWWTP). This study focused on accessing and quantifying any impacts of Carbondale Water Treatment Plant (CWTP) residual solids sewer discharge on biological treatment processes, effluent water quality, and sludge production at the SEWWTP. The Carbondale SEWWTP treats raw water influent through a number of physical and biological processes including screening, clarification, nitrification/denitrification, and aeration. Of the tests run as part of this study daily samples were collected of SEWWTP influent, mixed liquor, return sludge, and effluent and measured for changes in pH, biochemical oxygen demand (BOD), solids, sludge volume index (SVI), dissolved oxygen (DO), and nitrogen. No significant changes were documented other than percent BOD removal did improve after the introduction of the residuals. Anions were also tested weekly. Samples were collected from the SEWWTP’s oxidation ditch to monitor biological life using biological activity reaction tests (BART) for nitrifying, denitrifying, and heterotrophically active bacteria. BART testing showed no decline in biological activity and increased populations of denitrifying bacteria. Additionally, both metals and acute toxicity of SEWWTP effluent were tested by outside testing facilities to confirm that CWTP residual solids sewer discharge did not interfere with discharge limits established as part of the plant’s permits. No significant changes were observed during testing but plant staff did indicate that more extensive cleaning of the basins was implemented post-introduction. Overall, the case study confirmed that the treatment of CWTP residual solids sewer discharge did not negatively impact treatment processes at the SEWWTP and is sustainable.