Ciencias Exactas y Ciencias de la Salud
Permanent URI for this collectionhttps://hdl.handle.net/11285/551039
Pertenecen a esta colección Tesis y Trabajos de grado de las Maestrías correspondientes a las Escuelas de Ingeniería y Ciencias así como a Medicina y Ciencias de la Salud.
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- Characterization of the spatial variations in the structure and diversity of microbial communities within and between the stages of a wastewater treatment plant based on passive methods(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2017-11-24) Verduzco Garibay, Marycarmen; SENES GUERRERO, CAROLINA; 253929; Senés Guerrero, Carolina; tolmquevedo, emipsanchez; Anda Sánchez, José de; Escuela de Ingeniería y Ciencias; Campus Monterrey; Gradilla Hernández, Misael SebastiánWastewater is frequently discharged directly to water bodies without any treatment in developing countries. Despite the efforts to treat a higher percentage of sewage, wastewater treatment plants (WWTP) often end up abandoned due to the high maintenance and operational costs. Consequently, untreated wastewater often reaches water bodies and causes several pollution problems, such as eutrophication, affecting the communities' public health. To achieve the Sustainable Development Goal (SDGs) number six of the United Nations, which seeks to substantially improve water quality by 2030, lowering the release of pollutants and toxins into wastewater and safe reuse and recycling of treated water. It is crucial to switch from centralized to decentralized WWTP systems that require less maintenance and operation costs. Microorganisms are essential in wastewater treatment since they are involved in nutrient and organic matter removal through several metabolic pathways. However, microbial communities are susceptible to environmental variation, design and operational features of WWTP. Moreover, few studies have been performed focusing on the microbial communities within the treatment stages of complete decentralized systems. Therefore, this work's general objective was to characterize the spatial variations of the bacterial communities occurring in a decentralized wastewater treatment plant. This work is composed of three chapters. Chapter one describes the problem statement and context, research question, solution overview, and main contributions. Chapter two describes the types of constructed wetlands (CW) and the pollutant removal processes that occur within them. Additionally, this chapter discusses the effect of environmental parameters as well as operational and design factors on the structure, diversity, and activity of microbial communities. Chapter three presents the characterization of bacterial communities of a decentralized WWTP (the system under analysis) composed of a ST, an UAF, and a HFCW. Microbial characterization was carried out by high-throughput sequencing of 16S rRNA (V3-V4 region) to evaluate the spatial distribution of bacteria communities within a septic tank (ST), an up-flow anaerobic filter (UAF), and a horizontal flow constructed wetland (HFCW). Moreover, the effect of physicochemical parameters on the structure and diversity of bacterial communities was analyzed. Finally, chapter four describes future perspectives of this work and the importance of investigating the mechanisms to remove pathogenic microorganisms in the CW and the influence of iron in microbial communities' behavior during wastewater treatment.
- Mathematical Modelling of a Domestic Wastewater Treatment System Combining a Septic Tank, an Up flow Anaerobic Filter, and a Constructed Wetland(Instituto Tecnológico y de Estudios Superiores de Monterrey) Fernández del Castillo Barrón, Alberto; SENES GUERRERO, CAROLINA; 253929; Senés Guerrero, Carolina; puelquio, emipsanchez; De Anda Sánchez, José; Díaz Torres, Osiris; Escuela de Ingeniería y Ciencias; Campus Monterrey; Gradilla Hernández, Misael SebastiánWastewater treatment is essential for environmental protection, public health, and to ensure water supply for future generations. Conventional treatment technologies, such as activated sludge, are energy-intensive and require constant maintenance as they were designed for large cities. These technologies are not suitable for wastewater treatment in small communities and rural areas. Decentralized treatment approaches combining Anaerobic Reactors (AR) and Constructed Wetlands (CW) have proven more appropriate in these cases. These passive treatment methods require low investment and maintenance. Additionally, they allow for onsite water reuse and energy generation. The combined configuration of an AR sequentially coupled with a CW have proven to be an efficient system by which the limitations of the individual units (AR and CW) are overcome. Chapter one provides the motivation related to global needs of wastewater treatment, problem statement and context, which is the deficit of treatment and current technologies deficiencies. The research question and solution overview provided by the mathematical modeling applied to decentralized treatment technologies. Finally, the main contributions of this work to the state of the art are detailed. In Chapter 2, several systems combining three types of AR (Up-flow Anaerobic Sludge Blanket, Anaerobic Baffled Reactor, and Up-flow Anaerobic Filter) with CW are reviewed as well as their capabilities and drawbacks. An emphasis was made to analyze their performances, characteristics, and the processes involved in pollutant removal (solids, organic matter, nutrients, and sulfate). In Chapter 3, the experimental work of this thesis is presented. Mathematical modeling of the pollutant removal processes occurring in wastewater treatment plants can provide detailed and valuable information. More profound knowledge provided by these models is useful for predicting the future behavior of the treatment systems and can be applied to optimize the operation and facilitate monitoring. Optimal operation procedures and feasible monitoring are essential to ensure the successful implementation of these technologies in rural areas and small communities where investment budgets are limited. The system's efficiency and robustness can also be increased by applying mathematical modeling in design and control. The experimental system evaluated consisted of a Septic Tank (ST), an Up-flow Anaerobic Filter, and a Horizontal Flow Constructed Wetland (HFCW). Sampling was done biweekly for three months. BOD5, COD, TSS, TKN, ON, NH4+, NO2- and NO3- levels were measured. The experimental data was used to develop three different mathematical models: First order kinetics models, Linear Multiple Regression models, and Mass balance models. The first-order kinetic models developed were efficient to predict pollutant removal with significant precision. Multiple linear regression models were found to help reduce the cost and time of monitoring procedures. These models also reflected physical, chemical, and biological processes involved in pollutant removal in a logical manner. Finally, mass balance models indicated that the system is highly tolerant to influent wastewater variations.