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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- Sampling, identification, and characterization of microplastics and their associated emerging contaminants in wastewater effluents(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2025-06-02) González Hernández, Nazaret; Ornelas Soto, Nancy Edith; emipsanchez; Orona Návar, Angélica; School of Engineering and Sciences; Campus Monterrey; Aguilar Hernández, Iris AnahíMicroplastics are emerging pollutants of growing concern due to their persistence, widespread distribution, and capacity to act as vectors for hazardous chemicals. This study examines the presence, composition, and contaminant load of microplastics in the effluent of a wastewater treatment plant with a processing capacity of 7,500 liters per second in Nuevo León, Mexico. Samples were collected from final effluents and treated using the ASTM D8333-20 oxidation method to eliminate organic matter prior to analysis. Characterization via Raman spectroscopy revealed that the predominant polymers were polyethylene, polypropylene, and polystyrene, mainly present as fragments with a mean size of 198.3 μm. Color analysis indicated a predominance of white particles, suggesting a likely origin from disposable packaging materials. To detect sorbed organic contaminants, analytical techniques including Gas Chromatograph coupled with Mass Spectrometry and Gas Chromatography with an Electron Capture Detector were employed. Four volatile organic compounds were reliably identified: dimethyl disulfide, 2-butyl-1,1,3-trimethylcyclohexane, trichloromethane, and 1,1'-oxybis decane. Although polycyclic aromatic hydrocarbons were not detected, organochlorine pesticides such as γ-BHC (lindane), Endosulfan I, and Endosulfan sulfate were present, while polychlorinated biphenyls were not detected. Interference from linear hydrocarbons, fatty acids, and plasticizers was consistently observed, emphasizing the need for improved sample cleanup protocols. Based on effluent flow rates and particle concentrations, it is estimated that the wastewater treatment plant discharges over 4.97 × 10¹¹ microplastic particles annually. These findings highlight the urgent need for standardized monitoring approaches and advanced treatment strategies to mitigate the environmental and chemical risks associated with microplastic pollution in aquatic ecosystems.
- Application of nanoparticles for the mineralization of microplastics accumulated in wastewater in the context of Mexico city(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2022-12-05) Flores García, Victoria; Medina Medina, Dora Iliana; puemcuervo, emimayorquin; Sánchez Rodríguez, Elvia Patricia; School of Engineering and Sciences; Campus Ciudad de México; Cruz Martínez, HeribertoMicroplastics are anthropogenic pollutants that have acquired significant relevance in recent years due to their detection in the human body. This phenomenon is caused by the accumulation of these contaminants in the environment. Some of the health risks are immune responses such as chronic inflammation and oxidative stress, toxicity, and exposure to contaminants and pathogens. The currently applied strategies for plastic waste management do not remove efficiently the totality of microplastics. So, novel methods from the nanotechnology perspective have been evaluated. A new approach involving nanoparticles is the mineralization of microplastics. This method involves the catalysis of oxidative degradation reactions that destabilize the polymer’s structure. This research project evaluates the applicability of TiO2 nanoparticles for the mineralization of microplastics relevant to Mexico City (polyacrylonitrile, nylon 6, and poly (trimethyl terephthalate) by simulation of the monomer adsorption onto a (TiO2)10 nanocluster and the structural analysis of the modified geometries to identify possible bond cleavage sites and degradation products. From the simulation results, a chemisorption between the three monomers and the nanoclusters was identified. Additionally, the interaction between the structures aided in the activation of cleavage sites for polymer degradation.