Aplicación de maldi-tof imaging y hplc-ms/ms al estudio de la degradación del polímero policaprolactonadiol en diferentes medios acuáticos
- Autores: Daniel Rivas Becerra
- Directores de la Tesis: Antoni Ginebreda Martí (dir. tes.), Damià Barceló i Cullerés (codir. tes.), Santiago Gasso Domingo (tut. tes.)
- Lectura: En la Universitat Politècnica de Catalunya (UPC) ( España ) en 2017
- Idioma: español
- Tribunal Calificador de la Tesis: Joaquin Abian Moñux (presid.), Sara Rodríguez Mozaz (secret.), Thomas P. Knepper (voc.)
- Programa de doctorado: Programa de Doctorado en Ingeniería Ambiental por la Universidad Politécnica de Catalunya
- Materias:
- Enlaces
- Tesis en acceso abierto en: TDX
- Resumen
Water is essential for life, human activities and ecosystems. The global climate change together the population increase causes an imbalance between the demand of water and the available water resources.. All these factors lead to a increasing deterioration of human health and aquatic ecosystems.
The characterization of aquatic systems includes structural and functional aspects. In addition, it is necessary to emphasize the degradation of natural and anthropogenic organic matter Aquatic ecosystem ecology, to study the loss of organic matter, uses the weight loss of natural organic devices such as dry leaves or fragments of standardized wood that has been exposed to the environment.
Bearing this in mind, the main objective of this thesis was to add more chemistry knowledge into the river ecology by using of a synthetic material probe to study its degradation in natural and engineering aquatic environments. The device is based on a commercial polymer exposed for a while to different aquatic environments. The degradation of the synthetic material probe is collected and analyzed by using advanced mass spectrometry techniques such HPLC-MS, MALDI-TOF/MS and MALDI IMAGING.
Chapter 1 (Introduction) is distributed into three parts. The first presents the problems associated with the quality of the aquatic environment, their effects on ecosystems and succinctly describes the biotic and abiotic processes of degradation of organic matter and its application in WWTPs. In the second part there is a brief description of the polymers, their uses and degradation, as well as the analytical techniques used for their characterization. In the third part, we describe the mass spectrometry analytical techniques used in this thesis, emphasizing those that allow the study of space in two dimensions, through the corresponding generation of images (IMAGING).
The main objectives of the thesis are described in Chapter 2.
Chapter 3 describes the selection of possible polymers to be used, and the optimization of the analytical methodologies used by MALDI-TOF/MS. The chosen polymer was (polycaprolactone 1250). Probes consisting of a plastic capsule-piston with a sample of the polymer were prepared. Exposure experiments were carried out at various points of the Ebro River. The results obtained showed different types of degradation. Finally, these results were compared with those obtained in parallel using classical methods (using tree leaves). Chapter 4 describes laboratory-scale experiments performed with the selected polymer. These experiments consisted in exposing polymer samples for a time in aqueous systems, in sterile, aerobic and denitrifying conditions. The use of the novel MALDI IMAGING technique allowed the observation of degradation differences along the surface of the sample between the three types of conditions tested, obtaining images of the most interesting ions. Likewise, the statistical treatment of the results obtained was confirmed by the results of the images.
The success of the previous laboratory-scale experiment drove it to the next level and this experiment was applied it to wastewater samples. The WWTP El Prat de Llobregat was the site chosen, placing polymer probes in the secondary reactor, where the aerobic and denitrification (anaerobic) treatment are performed. The MALDI IMAGING technique was used to analyze the samples and high-resolution liquid chromatography coupled to mass spectrometry (HPLC-MS) was used as a complementary technique to elucidate the structures of the degradation compounds. The results obtained allowed to establish the degradation mechanisms and corresponding transformation products differentiated between the two types of environments studied. The description and results of this study is presented in Chapter 5.
Finally, in chapter 6 contains a general discussion of each experiment of this thesis.
