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A influência da salinidade nos processos de tratamento de efluentes por lodos ativados. / The influence of salinity in wastewater treatment processes by activated sludge.Luciana Silva dos Santos 07 March 2012 (has links)
O processo de tratamento de efluentes por lodos ativados é um dos processos de tratamento mais difundido em todo o mundo, devido principalmente a qualidade do efluente obtido. Entretanto, trata-se de um processo biológico dependente da atividade bacteriana para a estabilização da matéria orgânica proveniente dos esgotos e com isso, se faz necessária a manutenção das condições ideais para a sobrevivência e proliferação das bactérias e dos outros microrganismos envolvidos neste processo. Efluentes salinos causam um grande distúrbio na atividade celular dos microrganismos presentes neste processo. A análise biológica do lodo e a taxa de consumo de oxigênio são testes rápidos, práticos, baratos e sem geração de resíduos químicos e que foram adotados neste trabalho para acompanhar a eficiência do processo. Esses dois parâmetros são amplamente utilizados em pesquisas, porém ainda é sub-utilizado para efetivo monitoramento de Estações de Tratamento de Esgotos. Este presente trabalho investigou a influência da salinidade nos processos de lodos ativados através de parâmetros que levam em consideração a atividade metabólica dos organismos aeróbios e através do monitoramento da comunidade de protozoários indicadores biológicos do lodo ativado, os testes de respirometria e os testes da análise biológica do lodo, respectivamente. Os resultados da atividade metabólica são apresentados em forma de gráficos, em termos de taxa de consumo de oxigênio específico e porcentagem de inibição. Os resultados da qualidade biológica são apresentados em números de 0 a 10 de acordo com o Índice de Madoni (1994). Os resultados demonstraram a imediata intoxicação dos lodos ativados em concentrações de sal a partir da concentração mínima utilizada neste trabalho, que foi de 5 gL de NaCl. Para entender melhor o processo de intoxicação foi realizado experimentos de 96 horas de monitoramento após o choque de cloreto de sódio nos reatores com lodos ativados, os resultados não demonstraram melhoria no processo. Os resultados sugerem que os testes de taxa de consumo de oxigênio em consonância com os testes da qualidade biológica são eficientes e complementares para a avaliação da influência da salinidade no processo de lodos ativados. / Effluent treatment process by sludge activated is one of the most used processes of treatment all over the world, mainly because of the quality of the final effluent. However, this process is a biological one, and so, it depends on the bacterial activity to the stabilization of the organic matter of the sewage. Considering this, it is necessary to maintain the ideal conditions to the survival and proliferation of the bacteria responsible for the process. This work considered two parameters to evaluate the influence of the salinity in the sludge activated processes; these parameters are widely used in research, however, little used for the monitoring of the Wastewater Treatment Plants. The objectives of this work are to investigate the influence of the salinity through the respirometry test and the biological quality of the sludge. The results of the metabolic activity are presented in graphics, in terms of Oxygen Uptake Rate and percentage of inhibition. The results of the biological quality are presented in numbers by 0 to 10 according to the Mandonis Index (1994). The results show the intoxication of the sludge activated in saline concentrations higher than 5 g/L of NaCl in the saline shock, and it seems that efficiency do not get better even after 96 hours. The results suggests that the respirometry test and the biological quality test are efficient and complementary to the evaluation of salinity in the sludge activated processes.
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Measurement of analyte concentrations and gradients near 2D cell cultures and analogs using electrochemical microelectrode arrays: fast transients and physiological applicationsJose F. Rivera-Miranda (5930195) 12 October 2021 (has links)
This PhD research relates to the design,
fabrication, characterization, and optimization of on-chip electrochemical
microelectrode arrays (MEAs) for measurement of transient concentrations and
gradients, focusing on fast transients and physiological applications. In
particular, this work presents the determination of kinetic mechanisms taking
place at an active interface (either physiological or non-physiological) in
contact with a liquid phase using the MEA device to simultaneously estimate the
concentration and gradient of the analyte of interest at the surface of the
active interface. The design approach of the MEA device and the corresponding
measurement methodology to acquire reliable concentration information is
discussed. The ability of the MEA device to measure fast (i.e., in sub-second
time scale) transient gradients is demonstrated experimentally using a
controllable diffusion-reaction system which mimics the consumption of hydrogen
peroxide by a 2D cell culture. The proposed MEA device and measurement
methodology meet effectively most of the requirements for physiological applications
and as a demonstration of this, two physiological applications are presented.
In one application, the MEA device was tailored to measure the hydrogen
peroxide uptake rate of human astrocytes and glioblastoma multiforme cells in
2D cell culture as a function of hydrogen peroxide concentration at the cell
surface; the results allowed to quantitatively determine the uptake kinetics
mechanisms which are well-described by linear and Michaelis-Menten expressions,
in agreement with the literature. In the other application, further
customization of the MEA device was realized to study the glucose uptake
kinetics of human bronchial epithelial and small cell lung cancer cells, these
latter with and without DDX5 gene knockdown; the results allowed to distinguish
mechanistic differences in the glucose uptake kinetics among the three cell
lines. These results were complemented with measurements of glycolytic and
respiration rates to obtain a bigger picture of the glucose metabolism of the
three cell lines. Finally, additional applications, both physiological and
non-physiological, are proposed for the developed MEA device.
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Antibiotics in urban watersKäseberg, Thomas 27 October 2020 (has links)
The discovery of antibiotics is considered as one of the most significant scientific achievements of the 20th century – lives of millions of people and animals have been saved. Thenceforth, substantial amounts of administered antibiotics and their metabo-lites have been excreted into waste stream via urine and faeces. In this dissertation, primary focus is the qualitative balance of 14 antibiotics and one metabolite in urban water management and in urban waters, respectively. In particular, antibiotics pre-scribed to human beings are drained in the urban sewer system and finally enter the environment:
(i) Continuously via the effluent of the wastewater treatment plant after a partially effective removal or degradation or (ii) Intermittent via combined sewer overflow structures due to capacity limitations of the urban drainage system.
The fate and the potential effects and risks of these substances on ecosystems and hu-man health are of major concern – their direct toxic effect to all trophic levels as well as the global spread of antibiotic resistance genes are challenging. Hence, an assessment of microbial community activity due to antibiotic exposure is presented.
In particular, systematic work has been carried out to study the presence and character-istics of 14 antibiotics in urban waters. In detail, investigations were conducted to gain scientific knowledge with respect to adsorption, desorption, abiotic, biotic and photolyt-ic degradation as well as activity-inhibition of microorganism communities in sewage and of natural freshwater biofilm communities, respectively, due to inevitable urban drainage overflows.
In order to provide information to assist potential management strategies, which miti-gate surface water pollution and minimize the adverse impacts of antibiotics on activity of microorganism communities, the following specific topics were addressed:
⑴ The occurrence of 14 antibiotics and one metabolite were determined in sewag-es at three sampling sites in the city of Dresden, Germany.
⑵ The adsorption affinities of 14 antibiotics and one metabolite to size dependent sewer sediments were determined in experimental investigations, three sam-pling campaigns and subsequently an antibiotic-specific adsorption coefficient, normalized to organic content, was quantified.
⑶ The desorption affinity and -dynamics of 14 antibiotics and one metabolite were quantified in size dependent sewer sediments in experimental investigation and with statistical analysis.
⑷ The abiotic, biotic and photolytic degradation affinity of 14 antibiotics and one metabolite were quantified based on batch experiments with three different sewages at 7°C and 22°C, with artificial irradiation and different dilution ratios of the sewage at 30°C and subsequently a model framework decrypted ranges of abiotic, biotic and photolytic degradation coefficients.
⑸ The occurrence of three antibiotics, namely ciprofloxacin, clarithromycin and doxycycline was determined in sewage sampled during dry weather conditions in a small catchment of Dresden, which spills intermittently combined sewage (a mixture of sewage and storm water) to an adjacent brook in the case of capacity limitations of the urban drainage system during periods of intense rainfall and subsequently the three antibiotics were determined in the adjacent brook water.
⑹ Then, the activity-inhibition of microorganism community in sewage of this small catchment was quantified due to an exposition with three different antibiotics and three different antibiotic concentrations.
⑺ Last but not least, the activity-inhibition of natural freshwater biofilm communities in the adjacent brook was quantified via exposure to three antibiotics, which were individually dosed in three different concentrations, and also in mixture.
⑻ Finally, a two-dimensional hierarchical cluster analysis with dendrogram and heat map based on before mentioned activity inhibition of natural freshwater biofilm communities were conducted to identify hot spots of antibiotic tolerant and resistant bacterial subpopulations due to inevitable urban drainage system overflows.:List of Figures IV
List of Tables VIII
Symbols and Abbreviations XII
List of Publications on the Ph.D. topic XIX
1 General Introduction 2
1.1 Background 2
1.2 Aims and Objectives 3
1.3 Innovation and Contribution to the Knowledge 4
1.4 Outline of this Thesis 4
1.5 References 6
2 Adsorption and Desorption Affinity of 14 Antibiotics and One Metabolite for particulate components in urban drainage systems 10
2.1 Introduction 11
2.2 Materials and Methods 12
2.2.1 Study area 12
2.2.2 Sewer sediment and sewage sample collection 12
2.2.3 Sediment fractionation 13
2.2.4 Antibiotic determination in sewage and sediment 13
2.3 Results and Discussion 18
2.3.1 Antibiotics in composite sewage samples 18
2.3.2 Antibiotics adsorbed to sewer sediments 19
2.3.3 Organic-bound antibiotic load as a linear function of liquid concentration 20
2.3.4 Adsorption dynamics and adsorption coefficient determined by bath experiments 20
2.3.5 Mineral composition of sewer sediment SED#1B 23
2.3.6 Initial characteristics of sediment SED#1B 23
2.3.7 Desorption dynamics and desorption coefficient of SED#1B 24
2.4 Conclusions 25
2.5 References 26
3 Abiotic, Biotic and Photolytic Degradation Coefficients of 14 Antibiotics and One Metabolite 32
3.1 Introduction 34
3.2 Materials and Methods 35
3.2.1 Study area and sample collection 35
3.2.2 Experimental set up 35
3.2.3 Modelling framework 38
3.2.4 Procedure of model calibration 40
3.3 Results and Discussion 43
3.3.1 Primary metabolic parameter 43
3.3.2 Secondary metabolic parameter 44
3.4 Conclusions 50
3.5 References 50
4 Activity-Inhibition of Microorganisms due to an Exposition with different Antibiotics and Concentrations 56
4.1 Assessing Antibiotic Resistance of Microorganisms in Sanitary Sewage 56
4.1.1 Introduction 57
4.1.2 Material and Methods 58
4.1.2.1 Sampling Site and Antibiotic Agents 58
4.1.2.2 Analyzing Antibiotics 60
4.1.2.3 Respiration Rate 60
4.1.3 Results and Discussion 60
4.1.3.1 Concentration Range of Antibiotics and Typical Sewage Parameters 60
4.1.3.2 Oxygen Uptake Rate 62
4.1.4 Summary and Conclusions 63
4.1.5 References 64
4.2 Hot Spots of Antibiotic Tolerant and Resistant Bacterial Subpopulations in Natural Freshwater Biofilm Communities due to Inevitable Urban Drainage System Overflows 66
4.2.1 Introduction 68
4.2.2 Material and Methods 69
4.2.3 Results and Discussion 72
4.2.4 Conclusions 76
4.2.5 References 76
5 Summery and General Coclusions 82
5.1 Adsorption and Desorption Affinity 82
5.2 Abiotic, Biotic and Photolytic Degradation 83
5.3 Activity-Inhibition of Microorganism Communities due to Antibiotic Exposure 84
5.4 Enhancement of the Stockholm County Council (2014) assessment of antibiotics 84
5.5 References 87
6 Proposed Directions of Future Research 90
7 Appendixes 94
7.1 Chapters 94
7.2 Figures 95
7.3 Tables 115
7.4 References 139
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Semipermeable membrane devices as integrative tools for monitoring nonpolar aromatic compounds in airSöderström, Hanna January 2004 (has links)
<p>Air pollutants pose a high risk for humans, and the environment, and this pollution is one of the major environmental problems facing modern society. Active air sampling is the technique that has been traditionally used to monitor nonpolar aromatic air pollutants. However, active high volume samplers (HiVols) require a power supply, maintenance and specialist operators, and the equipment is often expensive. Thus, there is a need to develop new, less complicated sampling techniques that can increase the monitoring frequency, the geographical distribution of the measurements, and the number of sites used in air monitoring programs. In the work underlying this thesis, the use of semipermeable membrane devices (SPMDs) as tools for monitoring gas phase concentrations of nonpolar aromatic compound was evaluated using the compound classes polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), alkylated PAHs (alkyl-PAHs) and nitrated PAHs (nitro-PAHs) as test compounds. </p><p>High wind-speeds increased the uptake and release in SPMDs of PAHs and PCBs with log K<sub>OA</sub> values > 7.9, demonstrating that the uptake of most nonpolar aromatic compounds is controlled by the boundary layer at the membrane-air interface. The use of a metal umbrella to shelter the SPMDs decreased the uptake of PAHs and PCBs by 38 and 55 percent, respectively, at high wind/turbulence, and thus reduced the wind effect. Further, the use of performance reference compounds (PRCs) to assess the site effect of wind on the uptake in SPMDs reduced the between-site differences to less than 50 percent from as much as three times differences in uptake of PCBs and PAHs. However, analytical interferences reduced the precision of some PRCs, showing the importance of using robust analytical quality control.</p><p>SPMDs were shown to be efficient samplers of gas phase nonpolar aromatic compounds, and were able to determine local, continental and indoor spatial distributions of PAHs, alkyl- PAHs and nitro-PAHs. In addition, the use of the SPMDs, which do not require electricity, made sampling possible at remote/rural areas where the infrastructure was limited. SPMDs were also used to determine the source of PAH pollution, and different approaches were discussed. Finally, SPMDs were used to estimate the importance of the gas phase exposure route to the uptake of PAHs in plants. The results demonstrate that SPMDs have several advantages compared with HiVols, including integrative capacity over long times, reduced costs, and no need of special operators, maintenance or power supply for sampling. However, calibration data of SPMDs in air are limited, and spatial differences are often only semi-quantitatively determined by comparing amounts and profiles in the SPMDs, which have limited their use in air monitoring programs. In future work, it is therefore important that SPMDs are properly sheltered, PRCs are used in the sampling protocols, and that calibrated sampling rate data, or the SPMD-air partition data, of specific compounds are further developed to make determination of time weighted average (TWA) concentrations possible.</p>
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Semipermeable membrane devices as integrative tools for monitoring nonpolar aromatic compounds in airSöderström, Hanna January 2004 (has links)
Air pollutants pose a high risk for humans, and the environment, and this pollution is one of the major environmental problems facing modern society. Active air sampling is the technique that has been traditionally used to monitor nonpolar aromatic air pollutants. However, active high volume samplers (HiVols) require a power supply, maintenance and specialist operators, and the equipment is often expensive. Thus, there is a need to develop new, less complicated sampling techniques that can increase the monitoring frequency, the geographical distribution of the measurements, and the number of sites used in air monitoring programs. In the work underlying this thesis, the use of semipermeable membrane devices (SPMDs) as tools for monitoring gas phase concentrations of nonpolar aromatic compound was evaluated using the compound classes polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), alkylated PAHs (alkyl-PAHs) and nitrated PAHs (nitro-PAHs) as test compounds. High wind-speeds increased the uptake and release in SPMDs of PAHs and PCBs with log KOA values > 7.9, demonstrating that the uptake of most nonpolar aromatic compounds is controlled by the boundary layer at the membrane-air interface. The use of a metal umbrella to shelter the SPMDs decreased the uptake of PAHs and PCBs by 38 and 55 percent, respectively, at high wind/turbulence, and thus reduced the wind effect. Further, the use of performance reference compounds (PRCs) to assess the site effect of wind on the uptake in SPMDs reduced the between-site differences to less than 50 percent from as much as three times differences in uptake of PCBs and PAHs. However, analytical interferences reduced the precision of some PRCs, showing the importance of using robust analytical quality control. SPMDs were shown to be efficient samplers of gas phase nonpolar aromatic compounds, and were able to determine local, continental and indoor spatial distributions of PAHs, alkyl- PAHs and nitro-PAHs. In addition, the use of the SPMDs, which do not require electricity, made sampling possible at remote/rural areas where the infrastructure was limited. SPMDs were also used to determine the source of PAH pollution, and different approaches were discussed. Finally, SPMDs were used to estimate the importance of the gas phase exposure route to the uptake of PAHs in plants. The results demonstrate that SPMDs have several advantages compared with HiVols, including integrative capacity over long times, reduced costs, and no need of special operators, maintenance or power supply for sampling. However, calibration data of SPMDs in air are limited, and spatial differences are often only semi-quantitatively determined by comparing amounts and profiles in the SPMDs, which have limited their use in air monitoring programs. In future work, it is therefore important that SPMDs are properly sheltered, PRCs are used in the sampling protocols, and that calibrated sampling rate data, or the SPMD-air partition data, of specific compounds are further developed to make determination of time weighted average (TWA) concentrations possible.
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ESTIMAÇÃO DA TAXA DE CONSUMO DE OXIGÊNIO EM SISTEMAS DE LODO ATIVADO USANDO FILTRO DE KALMAN E CONTROLE PWM DA CONCENTRAÇÃO DE OXIGÊNIO DISSOLVIDO / ESTIMATION OF THE RATE OF OXYGEN CONSUMPTION IN ACTIVATED SLUDGE SYSTEMS USING KALMAN FILTER AND PWM CONTROL OF THE CONCENTRATION OF DISSOLVED OXYGENSilva, Francisco Jadilson dos Santos 29 July 2011 (has links)
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Previous issue date: 2011-07-29 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / The measurement and utilization of the oxygen uptake rate (OUR), or respiration rate, is very important in biological wastewater treatment process. The OUR provides information about the biological activity and may indicate the presence of the toxic elements capable of corrupting the system. Due to the lack of reliable real time sensors for measurement of the respiration rate, computer codes, based on estimation techniques, have been used to develop software sensors to overcome such difficulties. In this work a software sensor, using a Kalman Filter algorithm, is developed to estimate the OUR in an aerobic reactor, in which the dissolved oxygen concentration is controlled by aerators of on-off type triggered by pulse width modulation. Simulations and experimental results performed in a bench-scale activated sludge reactor are compared. It follows from the analysis of results, that the proposed method is able to estimate the OUR reliably and in real time. / A medição e a utilização da taxa de consumo de oxigênio (TCO), ou taxa de respiração, é muito importante para os processos biológicos de tratamento de águas residuais. A TCO fornece informações a respeito da atividade biológica e pode indicar a presença de elementos tóxicos capazes de comprometer a unidade de tratamento. Devido à carência de sensores confiáveis e em tempo real para a medição da taxa de respiração, programas de computador, baseados em técnicas de estimação, têm sido aplicados no desenvolvimento de sensores por software como uma alternativa para superar tais dificuldades. Neste trabalho um sensor por software, utilizando um algoritmo de Filtro de Kalman, é desenvolvido para estimar a TCO em um reator aeróbio no qual a concentração de oxigênio dissolvido é controlada por meio aeradores do tipo liga-desliga acionados por modulação por largura de pulsos. Simulações e resultados experimentais, obtidos em um reator de lodo ativado em escala de bancada, são comparados. Conclui-se, a partir da análise dos resultados, que o método proposto é capaz de estimar a TCO de forma confiável e em tempo real.
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