Orientador: Paulo Rodolfo Leopoldo / Banca: Jorge de Lucas Junior / Banca: Maria de Lourdes Conte / Resumo: Os efluentes de indústrias de chapa dura de fibra de madeira originários da exploração de eucalipto, são caracterizados por altos valores em DQO e material sólido em suspensão, tornando-os altamente poluentes para o ambiente e, principalmente, para os recursos hídricos. As empresas que atuam nesse segmento fazem o tratamento de seus efluentes de diversas maneiras, sendo a disposição por irrigação em solos cultivados, uma das formas utilizadas. Essa prática tem como base a melhoria da qualidade da água pela sua infiltração e principalmente pela evapotranspiração das plantas. Porém o lançamento em solos tem consequências, às vezes, muito graves, principalmente no que se refere a colmatação do solo e também à possível contaminação do lençol freático. O presente trabalho teve como objetivo o desenvolvimento de um sistema de tratamento de tais efluentes através do processo de peneiramento, visando a remoção das fibras em suspensão. Para isso desenvolveu-se um equipamento composto por peneiras rotativas substituíveis, com base em modelo francês, recomendado para o tratamento de efluentes industriais. Optou-se por esse sistema após a verificação da presença de grande quantidade de material sólido presente no efluente. Foram realizados 5 ensaios combinando-se peneiras rotativas de diferentes malhas (0,25 ; 0,50 ; 0,75 ; 1,00 e 1,50 mm) com suas respectivas rotações (13 ; 20 ; 33 ; 41 e 53 rpm) e vazões de entrada do efluente no sistema, que também foram 5 para cada ensaio. Para se verificar a influência do sistema proposto na redução da carga poluidora do efluente foram coletadas amostras na entrada do sistema (efluente "in natura") e na saída (efluente após peneiramento) totalizando 150 amostras. Nessas amostras foram analisadas as seguintes variáveis: ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The wastewater from hardboard industries coming from the eucalyptus exploration are characterized by high values of COD and suspended solid matter. For this reason, the wastewater significantly pollute the environment, specially the water resources. The industries that act in this area treat their wastewater by different ways. The irrigation of cultivated lands is one of the options for treatment of the wastewater. By using this procedure, there should be an improvement in the water quality because of its infiltration into the soil and because of the plant's evapotranspiration. However, the wastewater irrigation of the soil sometimes brings severe consequences, which are mainly related to the development of crusts on the soil surface and the possible contamination of the ground water. The objective of the present research was based on the development of a system to treat such wastewater by using the screening process, in order to remove the fibers in suspension. To do so, it has been developed an equipment that contains rotating changeable screens based on a French model that is recommended for the treatment of industry's wastewater. Five trials have been performed combining rotating screens with different nets (0.25, 0.50, 0.75, 1.00, and 1.50 mm) with their respective rotations (13, 20, 33, 41, and 53 rpm) and also with 5 different flows of the wastewater incoming in the system. In order to verify the influence of the proposed system on the reduction of the pollutant capacity of the wastewater, 150 samples were collected at the inlet of the system ("in natura" wastewater) and at it's outlet (wastewater after screening). From these samples, the following variables have been analyzed: total solids, fixed total solids, volatile total solids, pH, turbidity, electrical conductivity, COD, BOD, and... (Complete abstract click electronic access below) / Mestre

The biological process known as activated sludge (AS) in conjunction with membrane separation technology for the treatment of wastewater has been employed for over four decades. While, membrane biological reactors (MBR) are now widely employed, the phenomenon of membrane fouling is still the most significant factor leading to performance decline of MBRs. Although much research has been done on the subject of MBR fouling over the past two decades, many questions remain unanswered, and consensus within the scientific community is rare. However, research has led to one system parameter generally being regarded as a contributor to membrane fouling, extracellular polymeric compounds (EPS). EPS, and more specifically, the soluble fraction of EPS known as soluble microbial products (SMP), must be further investigated in order to better understand membrane fouling. The biological activity and performance of the MBR is affected by myriad operational parameters, which in turn affects the SMP generated. A commonly varied operational parameter is, depending on the specific treatment needs of a MBR, the sludge retention time (SRT). This study aims to characterize the SMP in three bench-scale MBRs as the SRT is gradually lowered. By studying how the SMP change as the operation of the system is altered, greater understanding of how SMP are related to fouling can be achieved. At the onset of the study, a steady state was established in the system with a SRT of 20 days. Upon stabilization of a 20 day SRT, the system was gradually transitioned to a five and a half day SRT, in stepwise adjustments. Initially, both the trans-membrane pressure (TMP) and the SMP concentrations were at relatively low values, indicating the presence of minimal amounts of biofilm on the membrane surfaces. As the system was altered and more activated sludge was wasted from the reactors, the SRT inherently decreased. As the lower SRT was transitioned and established, the data from TMP measurements, as well as the results from SMP determination, confirmed the development of increased amounts of biofilm formed. An apparent relationship was observed between the operational condition of a lower SRT and the SMP found in the system.

<p> Although both steady state and dynamic simulation studies of the activated sludge process are available, the data bases employed have traditionally been: derived from bench scale studies, derived from historical monitoring data, synthetic based on mathematical functions. Actual plant operating data, if available, would reflect full scale operation and would provide a much better data base to judge existing or future process models. This study was designed to provide a more comprehensive data base than presently existed on a full scale municipal activated sludge system. Both flow and component concentrations were continuously measured on two hour intervals for two periods of 10 days and 5 days duration. Streams sampled included the plant influent, the primary clarifier effluent, the aeration tank effluent, the secondary clarifier effluent, the activated sludge recycle and the waste sludge line. Based on total nitrogen and total phosphorus, the data were examined for mass flow closure around the aeration tank. A time dependent mixing model based on two unequal volume stirred tank reactors in series was found to adequately describe the observed variation in aeration tank input-output data. The measured aeration tank inflow and outflow was corrected to give a hydraulic balance using a statistical procedure which generates flow corrections based on expected measurement error. The resulting total nitrogen and total phosphorus material balances were found to improve based on a reduction of the residual sum of squares.</p> / Thesis / Master of Engineering (MEngr)

Thesis (M. Sc.)--University of Hong Kong, 1996. / Includes bibliographical references (leaf 59-62).

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No description available.

Over the past decade, the occurrence and removal of emerging contaminants in the environment has received much attention. Both natural and synthetic progestogens, which are hormones, and also benzotriazoles are two examples of such emerging contaminants. Sewage treatment works are recognised as one of the main routes of these compounds to the environment. Low concentrations (nanograms per litre) of biologically active chemicals may exhibit an impact on aquatic organisms and human health. This study was undertaken to determine the occurrence and removal of these two classes of chemicals at sewage treatment works, along with an evaluation of the performance of advanced treatment and also to investigate their fate in the aquatic environment. Therefore, field-based sampling campaigns were undertaken at a sewage treatment works, rivers and potable water to achieve these aims. Solid phase extraction and LC/MS/MS were used in order to analyse the samples from these different locations, along with catchment modelling and assessment of how the use of benzotriazoles may contribute to their presence in the environment. The results have demonstrated that progestogens and benzotriazoles are in the sewage system; the natural hormone (progesterone) was the most predominant compound entering the sewage treatment work (46.9 ng/l) among the progestogens while concentrations of the benzotriazoles were two orders of magnitude higher than the progestogens. The conventional sewage treatment works were, to some extent, able to remove these compounds from wastewaters. However, this may not be adequate to afford protection to the environment. The investigation of advanced treatments, ozone, granular activated carbon and chlorine dioxide, indicated no further significant removal of progestogens, probably as a result of concentrations being close to method detection limits. However, there were indications that benzotriazoles were removed. A degradation study demonstrated that the natural hormone (progesterone) was degraded rapidly while benzotriazoles were not degraded. Catchment modelling indicated that high (up to 2,000 ng/l) concentrations of benzotriazoles would be present in surface waters used for potable supply, and consequently benzotriazoles were found in the tap water with mean concentrations of 30.9 ng/l (benzotriazole) and 15.1 ng/l for tolyltriazole. It is therefore apparent that although conventional treatment may be seen as effective, achieving over 90% removal, this may not be good enough. However, before investing in tertiary treatment, a number of factors, such as the effectiveness at different sites, the presence of degradation products and costs, both financial and in relation to energy use, need to be considered.

This thesis aims to investigate and assess the future conditions for Volvo GTO Umeå after the installation of a new pre-treatment facility. The treatment method used is physical-chemical precipitation. Its function is to precipitate contaminants such as nickel, zinc and phosphorus, make them flocculate by adding a coagulant and separate the flocs by sedimentation. An investigation was carried out at the Volvo plant to locate the major inflow of waste water. These major inflows was analyzed and future scenarios was predicted by estimating a lower pre-treatment flow volume. The future scenarios showed that the volume and content will be greatly lowered. This will change many of the treatment plants performance factors, such as residence time, metal ion concentration and how much chemicals needed to treat the contaminants. Volvos physical-chemical precipitation plant was compared to the best available technique document drawn up in the framework of the implementation of the Industrial Emission Directive (2010/75/EU). The findings in the comparison showed that the Volvo plant works at a desirable degree and that the plant itself is considered best available technique when treating the current and future contaminants. Thus the physical-chemical precipitation technique can be used to treat the future waste water flows if the treatment plants performance factors are adjusted for.

Global efforts makes buildings successively more energy efficient. This results in that the percentage of the total energy in the building that is lost to the sewage system, in the form of hot water, is increasing. The characteristics of the wastewater originating from the urban water cycle makes it an attractive heat source which is relatively unexploited. Wastewater heat recovery (WWHR) systems is a group of systems designed to reduce a buildings use of external energy sources by recovering the heat out of the wastewater before it is let out into the sewage.         The focus of this report is a parametric study performed on a WWHR system that utilises thermal storage tanks for accumulation of wastewater and a heat pump equipped with heat exchangers for the heat recovery. The studied variables are the amount of energy that the system is able to recover out of the wastewater and the seasonal average COP of the heat pump. The change of these two variables were analysed both as an affect of parameters dependent of system design and on consumption patterns of the residents of the building. The results showed that by properly designing the system the recovery degree can be increased by 31.5 percentage points reaching values above 90 % and the seasonal average COP can be increased by 13.5 % reaching values of 5.13. However, these two variables stands in contrast to each other were maximising one will reduce the other and it is proposed that it is important to take both into account when evaluating a WWHR system. It is also shown that the consumption related parameters have a relatively big effect on the system. The change in recovery degree as a result of these non-controllable parameter is 14 percentage points and the seasonal average COP changes with 4.2 %.         The system performance as a result of changing the U-value of the heat exchanger connecting the system to the domestic hot water circuit was also analysed. This showed an exponential relation between the U-value and delivered energy from the heat pump. The results showed that an increase of the U-value from 50 W/K to 6000 W/K increased the yearly energy supplied with 37.6 % but an increase from 1000 W/K to 6000 W/K increased the yearly supplied energy with less than 1 %. This result highlights the importance of properly dimensioning the heat exchanger.

Com o intuito de viabilizar, ambiental e economicamente, a degradação de algumas substâncias perigosas e recalcitrantes, presentes em águas e efluentes, foi desenvolvido um sistema para estudar a tratabilidade dessas substâncias, utilizando Processos Oxidativos Avançados POAs. As espécies escolhidas foram o fenol (C6H5OH) a 50 mg L-1 e o cianeto de potássio (KCN) a 20 mg L-1. Os resíduos químicos foram submetidos a tratamentos com diferentes doses de O3 (0, 2,4 e 4,8 g h-1), H2O2 (0, 150 e 300 mg L-1 para o fenol e 0, 60 e 120 mg L-1 para o cianeto) e UV (0, 8 e 32 watts), pois tais combinações promovem a geração de radicais hidroxila (OH), cujo potencial de oxidação é superior ao de cada oxidante individualmente. O sistema desenvolvido funciona em batelada com recirculação, possibilitando todas as combinações de interesse entre os oxidantes, com capacidade máxima de 300 mL de resíduo, volume adotado para todos os testes deste trabalho. O sistema é composto por uma coluna cilíndrica disposta na posição vertical, ligada a um reator UV. Outros equipamentos instalados são a bomba para a circulação do resíduo, o concentrador de O2, o ozonizador (0-24 g h-1), cujo gás é insuflado pela base da coluna, e seu excesso passa pelo destruidor de O3, composto por uma coluna preenchida com carvão ativado. A solução de H2O2 é adicionada ao sistema com o auxílio de uma seringa. A eficiência do processo de mineralização do fenol, foi avaliada através de 27 tratamentos (combinações) nos tempos de 15 e 30 minutos e pH 6,5. As amostras coletadas foram analisadas em equipamento Shimadzu TOC-5000A, obtendo-se a concentração de carbono orgânico total. Os dados foram submetidos à análise estatística (Fatorial e teste de Tukey, p<0,05). As combinações com os melhores resultados foram utilizadas para uma segunda etapa de testes, variando os tempos em 5, 15, 30 e 45 minutos. Os novos dados foram submetidos à análise estatística e, novamente, as combinações com melhores resultados foram utilizadas para avaliação do efeito do pH (6,5 e 9,5) na mineralização do fenol. A combinação O3 (4,8 g h-1) / UV (32 watts) / H2O2 (300 mg L-1), em pH 9,5, apresentou a melhor condição de tratamento em 30 minutos, proporcionando 99,7% de mineralização do fenol. O delineamento experimental do cianeto foi baseado nas melhores razões oxidante/resíduo obtidas para o fenol. Foi preparada solução 8,13 mg L-1 de CN previamente alcalinizada (pH 11,0). Os tempos estudados foram 1, 2, 4, 5 e 10 minutos e as amostras foram submetidas à análise de N-NO3 por espectrofotometria em sistema por análise em fluxo. Neste caso a combinação O3 (4,8 g h-1) / UV (32 watts), proporcionou 97,6% da oxidação do cianeto à NO3 em 7 minutos de tratamento. Os custos dos tratamentos nas melhores condições foram de R$ 11,08 por litro de fenol tratado e R$ 4,20 por litro de cianeto tratado. Concluiu-se que o sistema proposto foi eficiente no tratamento de ambos resíduos químicos (fenol e cianeto) em um curto período de tempo / In order to facilitate, environmentally and economically, the degradation of some hazardous and recalcitrant substances, presented in waters and wastewaters, a system was developed to study the treatability of chemical substances using Advanced Oxidative Processes AOPs. The substances chosen were phenol (C6H5OH) at 50 mg L-1 and potassium cyanide (KCN) at 20 mg L-1. The chemical residues were submitted to treatments with different combinations and doses of O3 (0, 2.4, and 4.8 g h-1), H2O2 (0, 150 and 300 mg L-1 for phenol and 0, 60 and 120 mg L-1 for cyanide) and ultraviolet radiation (0, 8 and 32 watts), as these combinations promote the generation of hydroxyl radicals (OH), whose oxidation potential is greater than of each oxidant individually. The developed system works in batch treatments with recirculation, allowing all combinations of interests among the oxidants, with a maximum capacity of 300 mL of waste, adopted for all tests of this work. The system consists of a cylindrical column disposed in the vertical position and connected to a UV reactor. Other installed equipments are the pump for residual recirculation, the O2 concentrator, the ozonator (0-24 g h-1), which gas is blown from the base of the column and its excess is destroyed by the equipment composed of a glass column filled with granulate activated carbon. The solution of H2O2 is added to the system with the aid of a syringe. The efficiency of the mineralization of phenol was evaluated in 27 treatments in 15 and 30 minutes and pH 6.5. The collected samples were analyzed in Shimadzu TOC 5000A equipment, obtaining the concentration of total organic carbon (TOC). The obtained data were submitted to statistical analysis (Factorial and Tukey test, p<0.05). The combinations with the best results were used for a second phase of tests, varying the time at 5, 15, 30, and 45 minutes. The new data were submitted to statistical analysis and the best performing combinations were used to evaluate the effect of pH (6.5 and 9.5) in the mineralization of phenol. The combination of O3 (4.8 g h-1) / UV (32 watts) / H2O2 (300 mg L-1) at pH 9.5 showed the best treatment condition in 30 minutes, providing 99.7% of phenol mineralization. The experimental design of cyanide was based on the best oxidant/residue reasons obtained for phenol. A solution with 8.13 mg L-1 of CN previously alkaline (pH 11.0) was prepared. The treatment times were 1, 2, 4, 5 and 10 minutes and the samples were submitted to N-NO3 analysis by spectrophotometry system in flow injection analysis. In this case the combination O3 (4.8 g h-1) / UV (32 watts) provided 97.6 % of oxidation of the cyanide to NO3 in 7 minutes of treatment. The costs of treatments in the best conditions were R$ 11,08 per litter of phenol treated and R$ 4,20 per litter of cyanide treated. It can be concluded that the proposed system was effective in the treatment of both chemical residues (phenol and cyanide) in a short period of time