District heating has a long standing tradition in Sweden and today it is the most common way of producing and transporting heat. A District heating system (DH system) is divided into three parts: a production facility, distribution network (DH network) and one more heat stations. The heat produced in the facilities is distributed to the customers via a heat transfer medium, usually water (DH water), in piping networks that make up the DH network. The heat is transferred to the customers via the heat exchanger at which point they can use it as heated tap water or for heating purposes. The DH networks are often constructed in steel as it is cheap and a relatively resistant material. However it has the disadvantages of corrosion and expansions when it is exposed high temperatures which lead to damages in the DH network resulting in loss of the DH water, this is an unavoidable occurrence in any DH network. This results in addition of pollutants by leakages into the DH network or with the water that is used to compensate for the losses. The pollutants cause further corrosion, leading to metal contamination, and more damages on the DH network meaning there is a continuous degradation. Therefore various treatments are used to clean and ascertain an acceptable chemical environment in the DH systems. These treatments are effective but not at a level which is required so many chemicals are used to enhance the treatment of the water. Some of these are known to be toxic to humans and water ecosystems. As leakages are abundant and often end up in the WWTPs of the concerned municipality, which often have troubles with disturbances of the biological treatment, it was decided that an assessment of the toxic effects that DH water pose on activated sludge was to be investigated. This was done by testing water from two DH networks, Växjö and Kalmar, on the same activated sludge obtained from Tegelviken WWTP in Kalmar. A respirometric bioassay approach established by the Organization for Economic Co-operation and Development (OECD), OECD standard 209; OECD Guidelines for the Testing of Chemicals was used with changes made to exposure and measuring time as this decrease the risk of misinterpretation of the results. A dilution series using different concentrations (6.25%, 25% and 100%) of DH water was tested and compered to a blank control samples containing only activated sludge. Assessment of toxicity on total oxidation, oxidation carbon and oxidation of nitrogen was made. To get some idea of what might cause toxic effect samples of the waters was sent to outside laboratories for analyses of metals. The result from the bioassay and metal analysis was used to formulate risk factors associated with a DH water spill and exposure to WWTPs. It was found that both DH waters have a significant inhibition on nitrification in WWTPs. The DH water from Kalmar exhibited similar toxicity dynamics, roughly 20% inhibition, despite large differences in concentration. The DH water from Växjö showed a negative correlation between an increase in concentration of DH water and toxicity, 74% for the lowest concentration and 11% for the highest. The metal analysis concluded that there was no abundance of metal contamination which led to the inference that toxicity is probably caused by the chemicals used for treatment. This poses a great risk for the Baltic Ocean as many WWTPs release their treated water directly into water courses with a short detention time before reaching the sea.

From June to November 2007, a microscopic analysis was conducted on the activated sludge from eleven selected wastewater treatment plants (WWTP's) belonging to the City of Cape Town. The primary objective was the identification of the dominant and secondary filamentous organisms. Other important criteria included were the floe character, diversity, filament index (Fl) and identification of the protozoan and metazoan communities. The operational data determined from routine analyses of the sludge, influent and effluent were used to assess the relationship of the filamentous population to wastewater characteristics and to compare this with previous findings. Fl values of >3 and dissolved sludge volume indices (DSVI's) of >150 were chosen as representing the possibility of bulking conditions being present. The five most prevalent dominant filaments were Type 0092, Type 1851, actinomycetes, Microthrix parvicella and Type 021N, being present in 74%, 31%, 22%, 17% and 14% of samples respectively. Type 0092 did not appear to be associated with bulking in any of the WWTP's, although it was often incidentally present as a co-dominant species when bulking conditions existed. All three WWTP's with the Modified Ludzack-Ettinger configuration harboured Type 1851 as the major dominant species, irrespective of whether the plants treated domestic or industrial effluent. Conditions suggestive of bulking were present in two of these WWTP's. Contrary to expectations, Type 1851 was often found as a dominant species where domestic waste was the primary influent. Type 021N and actinomycetes were strongly implicated when bulking occurred. The overgrowth of these filaments appeared to be related to factors such as nutrient deficiency (Type 021N) or the presence of large amounts of low molecular weight substances in the influent. Microthrix parvicella did not cause major bulking problems. There was a strong association between low levels of nitrates/nitrites in the clarifier supernatant and good phosphorous removal, irrespective of the configuration of the WWTP. The converse was also true. / Thesis ((M. Environmental Science))--North-West University, Potchefstroom Campus, 2009.

From June to November 2007, a microscopic analysis was conducted on the activated sludge from eleven selected wastewater treatment plants (WWTP's) belonging to the City of Cape Town. The primary objective was the identification of the dominant and secondary filamentous organisms. Other important criteria included were the floe character, diversity, filament index (Fl) and identification of the protozoan and metazoan communities. The operational data determined from routine analyses of the sludge, influent and effluent were used to assess the relationship of the filamentous population to wastewater characteristics and to compare this with previous findings. Fl values of >3 and dissolved sludge volume indices (DSVI's) of >150 were chosen as representing the possibility of bulking conditions being present. The five most prevalent dominant filaments were Type 0092, Type 1851, actinomycetes, Microthrix parvicella and Type 021N, being present in 74%, 31%, 22%, 17% and 14% of samples respectively. Type 0092 did not appear to be associated with bulking in any of the WWTP's, although it was often incidentally present as a co-dominant species when bulking conditions existed. All three WWTP's with the Modified Ludzack-Ettinger configuration harboured Type 1851 as the major dominant species, irrespective of whether the plants treated domestic or industrial effluent. Conditions suggestive of bulking were present in two of these WWTP's. Contrary to expectations, Type 1851 was often found as a dominant species where domestic waste was the primary influent. Type 021N and actinomycetes were strongly implicated when bulking occurred. The overgrowth of these filaments appeared to be related to factors such as nutrient deficiency (Type 021N) or the presence of large amounts of low molecular weight substances in the influent. Microthrix parvicella did not cause major bulking problems. There was a strong association between low levels of nitrates/nitrites in the clarifier supernatant and good phosphorous removal, irrespective of the configuration of the WWTP. The converse was also true. / Thesis ((M. Environmental Science))--North-West University, Potchefstroom Campus, 2009.

This thesis was the report of the research done on the near-critical water gasification (NCWG) as an application for activated sludge treatment. The research started with the use of model compounds and binary mixtures of these compounds as feeds for the NCWG. High gasification yields were obtained using a commercial catalyst (Raney nickel), and it was found that interactions between model compounds in the binary mixtures resulted in lowering the gasification efficiencies. The research then shifted to the use of actual activated sludge samples and the search for novel catalysts for that application. Almost 70% of the sludge was gasified in the presence of the high amounts of Raney nickel. Hydrogen was the main product in the gas phase. However, Raney nickel lost half its activity after only 8 minutes of exposure to supercritical water. For some model compounds, novel catalysts formulated in our laboratories had better activities than the commercial ones. This was not the case for the NCWG of activated sludge.

This thesis was the report of the research done on the near-critical water gasification (NCWG) as an application for activated sludge treatment. The research started with the use of model compounds and binary mixtures of these compounds as feeds for the NCWG. High gasification yields were obtained using a commercial catalyst (Raney nickel), and it was found that interactions between model compounds in the binary mixtures resulted in lowering the gasification efficiencies. The research then shifted to the use of actual activated sludge samples and the search for novel catalysts for that application. Almost 70% of the sludge was gasified in the presence of the high amounts of Raney nickel. Hydrogen was the main product in the gas phase. However, Raney nickel lost half its activity after only 8 minutes of exposure to supercritical water. For some model compounds, novel catalysts formulated in our laboratories had better activities than the commercial ones. This was not the case for the NCWG of activated sludge.

L’origine de ce travail est principalement les effets biologiques potentiels des ondes électromagnétiques de la gamme non ionisante rencontrés dans la littérature et quelques faits observés par des clients de la technologie commercialisée par la société Planet Horizon SA. Les essais de couplage du traitement aux ondes électromagnétiques et les procédés de traitements des eaux usées par boues actives sont réalisés à niveau industriel au sein de la STEP de Penthaz (Suisse) compose de 2 lignes parallèles et sur des pilotes de laboratoire en mode SBR. Le traitement électromagnétique de très basse fréquence (Antennes émettant deux fréquences harmoniques F1 et F2 < 10 kHz) est appliqué via 5 antennes dans le bassin d’aération ou une antenne sans le SBR directement. Dans une autre expérience , des tubes, émettant les mêmes fréquences, sont utilisés pour le recyclage de la liqueur mixte avec toujours une ligne de référence. Au niveau de la STEP, dans le bassin d’aération le traitement électromagnétique a permis une réduction de la quantité de biomasse produite au niveau de l’essai de l’ordre de 42,5% par rapport à ligne témoin. De plus, ce traitement électromagnétique n’affecte pas la qualité de l’eau épurée puisque la quantité de DCO résiduelle est la même à la sortie des deux ligne (REF et EM) et le rendement d’abattement de la matière organique est de l’ordre de 94% pour les deux lignes. Par contre à l’échelle du laboratoire, les résultats obtenus après le couplage du traitement électromagnétique n’ont aucun effet sur la quantité de biomasse produite dans les différents essais avec antenne ou bobine comme étant des émetteurs d’ondes EM. De même, on ne remarque aucun effet significatif sur les rendements de dépollution. La deuxième partie concerne l’application de ces mêmes ondes sur la formation de biofilm microbien. Les champs électromagnétiques visés sont des faibles champs de quelques dizaines de milli-teslas au niveau du générateur (tension de l’ordre de la dizaine de volts et intensité de l’ordre d’un ampère) avec des fréquences comprises entre 0 et 10 kHz; deux ondes de fréquences harmoniques sont imposées simultanément. Le biofilm est quantifié au cours du temps grâce à la mesure de différents paramètres (densité optique, DCO, protéines, ATP, exopolysaccharides). Les résultats expérimentaux démontrent que l’onde électromagnétique limite la formation du biofilm si la continuité hydraulique est assurée entre la bobine électromagnétique et les supports de biofilm ; la quantité de biofilm mesurée est alors deux fois plus faible environ. Cependant, l’effet semble bactériostatique et non bactéricide : l’application de l’onde ne détruit pas le biofilm mais réduit sa formation car dès l’arrêt de l’onde, la vitesse augmente. Des signaux électriques de quelques millivolts et dans le domaine des très basses fréquences ont été détectés seulement dans la cuve en continuité hydraulique avec le générateur d’ondes et située à une distance de 1m environ. Des mesures de champs électromagnétiques dans l’air donnent des intensités de champs très faibles ne pouvant expliquer un effet thermique ou ionisant sur le biofilm. / The first part of this work concerns the coupling of VLF electromagnetic waves treatment and the processes of wastewater treatment by activated sludge in order to reduce excess sludge. Experiments are made at real -scale ( Penthaz , Switzerland),containing two parallel lines and at lab-scale with SBR pilots. The electromagnetic treatment of very low frequency ( antennaemitting harmonic frequencies F1 and F2 <10 kHz) is applied via 5 (2,3x1m) antennas in the aeration basin of the real plant. Other type of antenna (30x 5 cm) was configurated for one of the labscale assays. In the other lab-scale experiment, tubes emitting the same frequency are used for recycling the mixed liquor. With the WWTP, the amount of excess sludge produced in the treated line is reduced by about 42.5%, compared to the control line. In addition, the electromagnetic treatment does not affect the quality of treated water. In this case, outlet COD concentration was similar for the the two lines (REF and EM) and the reduction of or ganic matter yield was about 94% for the two lines. Electromagnetic treatment had no effect on the amount of excess biomass produced in all tests conducted at lab-scale. No significant effect has been noticed regarding depollution yields. The second part aims to better understand the interaction between an electromagnetic wave of very low frequency and biological material and, in particular, the effects on the development of microbial biofilms. Electromagnetic fields are covered weak fields a few milli-Tesla (voltage of the order of tens of volts and intensity of the order of one ampere) with frequencies between 0 and 10 kHz, two waves of harmonic frequencies are transmitted simultaneously. The biofilm was quantified over time by measuring different parameters (optical density, COD, protein, ATP, exopolysaccharides). The experimental results how that the electromagnetic wave limit biofilm formation ( close to 50% of untreated biofilm) if the hydraulic continuity is ensured between the electromagnetic coil. However, the effect appears bacteriostatic and no antibacterial : the application of the wave does not destroy the biofilm but reduced its establishment and upon discontinuation of the wave, the growth increases. Measurements and modeling of electromagnetic fields in the air give intensities of very weak fields that can explain a thermal or ionizing effect on the biofilm.

Deficiencies in biotreatment due to uncontrolled growth of filamentous microorganisms is a problem for wastewater plants worldwide. The project was assigned with the task of reducing the growth of filamentous bacteria at the paper mill SCA Munksund. 12 bacteria and 1 fungi species were presented to the project as problematic due to their filamentous properties. Operating parameters affecting filamentous growth was examined and presented. The information gathered showed that a decrease in filamentous growth for 5 especially problematic bacteria could possibly be achieved by raising the DO, increasing the concentration of nutrients and decreasing the sludge age. Other parameters affecting the growth of filamentous bacteria, such as pH, temperature and F/M were found to be too diverse among the examined species. Alternative solutions not focused on finding optimal operating parameters was also investigated. Promising results were treatment using a feast-famine approach, installation of an anaerobic selector and ozonation of return sludge. A statistical analysis was also performed on operating data. Methods used were Principal component analysis, Clustering and Logistic regression. These were used as a proof of concept rather than providing meaningful data for an operating window.

Dissertation submitted in compliance with the requirements of the Master's Degree in Technology in Biotechnology, Durban Institute of Technology, 2003. / The measured kinetics of a bacterial culture degrading a single organic compound as a sole carbon source in a batch reactor depends on the history of the culture, the identifiability of the parameters, and the manner in which the experiment to measure them is run. The initial substrate to biomass ratio (So/Xo) used in the experiment is particularly important because it influences both parameter identifiability and the expression of the culture history. / M

As estações de tratamento de esgotos por lodos ativados são caracterizadas por modelos cinéticos de comportamento não linear de difícil parametrização. A utilização de técnicas de identificação paramétricas para a modelagem de tais estações produz modelos com parâmetros sem significado operacional e variantes no tempo. Por outro lado, a lógica nebulosa permite ao usuário de modelos baseados em tal técnica uma parametrização mais próxima do raciocínio humano. A facilidade da parametrização nebulosa reside na atribuição de valores lingüísticos às variáveis de entrada do modelo. Esta dissertação utiliza técnicas de modelagem nebulosa, como ANFIS e regras limitadas, para identificar o comportamento da concentração de oxigênio dissolvido do tanque de aeração do benchmark de uma planta de tratamento de esgotos por lodos ativados com remoção de nitrogênio. / Activated sludge wastewater treatment plants are characterized by kinetic models of highly nonlinear behavior, whose time varying parameters are very difficult to calibrate. The use of parametric identification techniques to build models of such plants results in models with parameters without operational meaning. Alternatively, the fuzzy logic enables users of models, which are based on this technique, a parametrization similar to human reasoning. The simplicity of the fuzzy logic consists of the attribution of linguistic labels to the model input variables. This dissertation uses fuzzy logic techniques, such as ANFIS and limited rules, to identify the behavior of the dissolved oxigen in the aeration tank of a benchmark activated sludge wastewater treatment plant, with nitrogen removal.

Orientador: Regina Maura Bueno Franco / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-08T19:15:28Z (GMT). No. of bitstreams: 1 Santos_LucianaUrbanodos_D.pdf: 2872201 bytes, checksum: 3d486b0bfc4357c133c090e92209db49 (MD5) Previous issue date: 2007 / Resumo: Entre muitas doenças de veiculação hídrica, a criptosporidiose e a giardiose são de particular interesse para a Saúde Pública, porque oocistos de Cryptosporidium spp e cistos de Giardia spp. podem persistir por longos períodos no ambiente, sendo que estes dois protozoários patogênicos têm sido implicados como a causa de muitos surtos epidêmicos de gastroenterites nos últimos 25 anos.Em muitos desses surtos, o esgoto doméstico foi incriminado como a fonte de contaminação do manancial; os variados métodos de tratamento de esgoto não removem totalmente agentes patogênicos, evidenciando a necessidade de desinfecçãodo esgoto tratado antes do seu lançamento no corpo hídrico. Uma forma de tratamento de esgoto amplamente utilizada é o processo por Iodos ativados, onde a degradação da matéria orgânica é realizada por bactérias aeróbicas.Em função da resistência de Cryptosporidium spp e Giardia spp. Ao processode desinfecção por cloração, a radiação por luz ultravioleta (UV) têm sidoavaliada como um processo alternativo. Para avaliar a eficiência de remoção de oocistose cistos pelo processo de Iodo ativado e de um reator de luz UV em inativaroocistos e cistos em uma Estação de Tratamento de Esgoto (ETE) da cidadede Campinas, 3 tipos de amostras foram selecionados para o estudo: I) afluente (n=53), iii) efluente desinfetado por luz UV (n=38) e, iii) efluente sem desinfecção por luz UV (n=53). As amostras de afluente foram concentradas por centrífugo-concentraçãoe as amostras de efluente (desinfetadas ou não por luz UV) foram processadas por filtração em membrana de éster de celulose) e, a visualizaçãodos protozoários, feita pela reação de imunofluorescência direta, com anticorposmonoclonais. A avaliação do processo de desinfecção por luz UV foi realizada com experimento de infectividade animal, inoculando-se 14/ cistos camundongos da linhagem BALB!c nude. Cistos de Giardia spp foram mais freqüentes e em maior densidade nos três tipos de amostras. Oocistos de Cryptosporidiumspp. foram observados somente em 2 amostras de afluente e em apenas uma amostra de efluente desinfetado por luz UV. O tratamento de esgoto pelo processo de Iodo ativado reduziu 98,9 % dos cistos e 99,7 % dos oocistos. A administração intragástrica de cistos de Giardia spp. desinfetados ou não por luz UV em camundongos, resultou na liberação de cistos de Giardia spp., nas fezes e trofozoítos foram observados nas lâminas confeccionadas por aposição do intestino. Estes resultados indicam que a desinfecção por luz UV não foi completamente eficiente na inativação dos cistos de Giardia spp, no caso da ETE estudada / Abstract: Among many water-borne diseases the cryptosporidiosis and giardiosis are of particular public health interest, because Cryptosporidium spp. oocysts and Giardia spp. cysts can persist for long periods in the environment, and both pathogenic protozoa have been implicated as the cause of many outbreaks of gastroenteritisin the last 25 years. In many of those outbreaks, the domestic sewer was incriminated as to source of contamination of the spring; they varied treatment sewage approaches do not remove entirely agent's pathogens, showing up the need of disinfection of the treated effluent before of their launching in the water body.A form of address of sewer broadly utilized is the trial by activated sludge whichway the degradation of the organic matter is carried out by aerobic bacteria and, in function of the resistance of Cryptosporidium spp and Giardia spp. to the chlorinedisinfection, the ultraviolet light (UV) has been evaluated like an alternative trial of disinfection. In order to evaluate the efficiency of cysts and oocysts removal by the activated sludge process, and by a UV reactor in inactivating cysts and oocystsin one Wastewater Treatment Plant (Wl/VTP)in Campinas, three sampling points were selected for study: i) influent (n=53),iii) treated effluent with UV disinfection (n=38) and iii) treated effluent without UV disinfection (n=53). The influent samples were concentrated by centrifugation and effluent samples (disinfectedwith UV light or not) were processed by cellulose esters membrane filtration, and protozoan visualization was analyzed by fluorescent monoclonal antibodytests. The investigation of disinfection potential by UV light was made with infectivityassay. Each mice of linage BALB/c nude were intragastrically inoculated a mean dosage 14 cysts. Giardia spp cysts prevailed with higher density in the three different sample types. Cryptosporidium spp. oocysts were observed in only 2 samples of influent and in just one sample of treated sewage with UV disinfection.The treatment by the activated sludge process promoted a reduction of 98.9% of cysts and 99.7 % of oocysts. Gastric intubation of Giardia spp. Cysts disinfected ar not by UV light to mice resulted in cysts released in feces and trophozoiteswere also observed toa in intestinal scrapings. The findings of this study indicate that disinfection by UV light was not completely efficient regarding the inactivationof Giardia spp cysts in the case of the / Doutorado / Doutor em Parasitologia