No description available.

No description available.

No description available.

No description available.

No description available.

D.L. A 792-2008 / Ministerio de Educación y Ciencia; Programa FEDER; Generalitat Valenciana; Universidad de Alicante.

No description available.

Pharmaceuticals have been detected in natural waters for more than forty years, but with improvements in sample preparation procedures and analytical instrumentation, the number of scientific publications on the issue has increased significantly. Even though the concentration of pharmaceutical residues in surface and drinking water is not critical for human health according to the present level of knowledge, the consequences for the environment are not clear. Wastewater treatment plants (WWTPs) have been identified as the primary route of pharmaceuticals to the environment, with households as the major source point for most of the over-the-counter and prescription drugs. In this thesis, the first aim was to study the occurrence, fate and removal of 43 pharmaceuticals during conventional wastewater treatment. The target compounds were selected on the basis of their high consumption in Spain or/and frequently reported detection in wastewaters and the possibility to be analyzed under the same experimental conditions. They belong to different therapeutic classes, i.e. nonsteroidal anti-inflammatory agents and analgesics, lipid modifying agents, psycholeptic and antiepileptic drugs, beta-blocking agents, beta-2-adrenoreceptor agonists, H2-receptor antagonists, antibiotics, angiotensin converting enzyme agents, diuretics and antidiabetic drugs. A wide variation in removal efficiencies was observed even for individual compounds, and across therapeutic classes and treatment processes, without clear conclusion on the removal of any particular compound. According to mass balance calculations and estimated partition coefficients, the loss of the selected pharmaceuticals during biological wastewater treatment can be fully attributed to biodegradation/biotransformation. None of the studied compounds was entirely biodegraded and/or transformed during biological wastewater treatment, but the measured concentrations were below the levels of concern according to available toxicity data. Conventional WWTPs cannot be expected to be the only mechanism for controlling the entry of pharmaceuticals into the environment because they were neither designed nor can provide their complete removal. Therefore, the challenge is to look for solutions that would be the most economical and effective means of preventing further pollution of natural waters by pharmaceuticals. More appropriate management of sewage waters before they enter treatment plants as well as a stricter control of effluent discharges, along with an in-depth investigation on the development of new designs and strategies for the improvement of existing wastewater treatments should be considered. In light of this, as the second objective of this thesis, alternative approaches for the removal of the antiepileptic carbamazepine (CBZ) were studied in aqueous media in two laboratory scale experiments: a) biodegradation using white rot fungus T. versicolor in an air-pulsed fluidized bioreactor operated in batch and continuous modes, and b) advanced oxidation using TiO2-heterogeneous photocatalysis under simulated solar and UV-A irradiation, and under the combined use of ultrasound and UV-A irradiation (sonophotocatalysis). We selected CBZ as a representative example of compounds that are found to be refractory to biological treatment and ubiquitous in various environmental matrices. Both, the fungal and UVA-driven TiO2-photocatalytic treatments, very different in their nature, have been shown to be very effective in degrading carbamazepine in aqueous media. The fungal treatment resulted in average removals of 54 and 96% in batch and continuous reactor, respectively. Acute toxicity test using the bioluminescent marine bacterium Vibrio fischeri showed a decrease in toxicity during the treatment in both types of bioreactor. In the other study, initial CBZ concentrations were reduced for 95% during 120 min of the UV-driven photocatalytic experiment and sonophotocatalysis, while only 10 % of CBZ was photodegraded during under solar irradiation. A slight increase in toxicity in Daphnia magna acute toxicity testing was observed over the time-course of the photocatalytic experiments, which can be associated with the formation of transformation products of CBZ. Ultraperformance liquid chromatography coupled to a quadrupole-time-of-flight mass spectrometry was used for a tentative identification of the transformation products of CBZ formed during the performed experiments. Most of the tentatively identified intermediates exhibited only slight modifications of the CBZ molecular structure. The fungal as well as the photocatalytic processes yielded oxygenated transformation products. In the biological treatment using T. versicolor, transformation products were formed by enzymatic epoxidation and hydroxylation of seven-membered heterocyclic ring of the carbamazepine molecule. During the photocatalytic experiments, CBZ-related transformation products emerged from hydroxylation and further oxidation of different parts of the molecule of carbamazepine. The generated transformation products appeared to be more persistent than their parent compound, as they were present, although at low concentration, until the end of the experiments. The results of the thesis contribute to a better understanding of a) the magnitude of the selected pharmaceuticals that reach the environment through the wastewater and sludge discharge, b) the efficiency of typical conventional wastewater treatment plants regarding the removal of these compounds from raw wastewater, and c) possible developments of alternative technologies for their enhanced elimination. / Desde hace más de cuarenta años se ha detectado la presencia de fármacos en el ciclo de aguas, sobre todo debido a los avances en la química analítica que han permitido el desarrollo de nuevas metodologías analíticas para la determinación de estos compuestos de modo fiable y a bajas concentraciones. Las estaciones depuradoras de aguas residuales (EDARs) han sido identificadas como la ruta principal de entrada de fármacos de origen humano en el medioambiente. Por tanto, el principal objetivo de esta tesis ha sido el estudio de la presencia, destino y eliminación de 43 fármacos seleccionados, durante el tratamiento convencional realizado en las EDARs. Los compuestos estudiados fueron seleccionados en base a los índices de consumo en España, a la frecuencia de detección en aguas residuales y además en base a la posibilidad de ser analizados bajo las mismas condiciones experimentales. Estos compuestos pertenecen a diferentes clases terapéuticas, i.e. antiinflamatorios no esteroideos , los agentes que reducen los lípidos séricos, ansiolíticos y antiepilépticos, los agentes bloqueadores beta-adrenérgicos, agonistas β2 adrenérgico, antagonistas H2 , antibióticos, inhibidores de la enzima convertidora de angiotensina, diuréticos y antidiabéticos. Para el análisis cuantitativo se utilizó la cromatografía de líquidos acoplada a espectrometría de masas en tándem (LC-MS/MS), empleando un sistema híbrido triple quadrupolo/trampa de iones lineal. Como segundo objetivo hemos considerado evaluar tratamientos avanzados alternativos al tratamiento convencional para la eliminación de un fármaco antiepiléptico, la carbamazepina, uno de los compuestos más recalcitrantes al tratamiento biológico convencional. Se procedió a estudiar su degradación en medio acuoso mediante dos procedimientos a escala laboratorio: a) biodegradación utilizando el hongo ligninolitico Trametes Versicolor en un reactor fluidizado por pulsos de aire operando en modo batch y continuo, y b) oxidación avanzada mediante un tratamiento fotocatalitico en presencia de TiO2 bajo irradiación UV-A y solar, y aplicando la radiación UV en combinación con ultrasonidos (sonofotocatálisis). Para la evaluación de los tratamientos alternativos, se identificaron los productos de transformación de la carbamazepina, y se evaluó la toxicidad de las muestras tratadas. Se utilizó la LC-MS/MS con analizador de tipo cuadrupolo-tiempo de vuelo. También se evaluó la toxicidad de las muestras tratadas.

This thesis is focused on two environmental issues. The first one is the recovery of different wastes, such as sewage sludge and fly ashes, and the second one is related to the removal of odour causing compounds which are generated in the same waste water treatment plant (WWTP), like NH3 and H2S. Direct alkaline activation with NaOH and KOH of two sludges which have different specific treatments in the sewage sludge line, has been studied, and it has been compared with the activation of their chars. Two different heating mechanisms were applied: conventional heating and microwave oven heating. All the sewage sludge-derived materials are tested for NH3 removal adsorption experiments. On the other hand it has been studied the preparation of adsorbents by mixing on sewage sludge with fly ashes heated in a microwave oven. The materials adsorbents have a limited development of porosity and are tested for H2S removal. / Esta tesis se centra en dos problemáticas medioambientales. Una es la valorización de residuos, como son los lodos de depuradora y cenizas volantes, y la otra incide en la eliminación de compuestos causantes de malos olores que se generan en las estaciones depuradoras de agua residual (EDARs), como son el NH3 y el H2S. Se ha estudiado la activación alcalina directa con NaOH y KOH de dos lodos, que emplean procesos diferentes en su línea de lodos, y se ha comparado con la activación de sus respectivos pirolizados, usando dos tipos de calentamiento: convencional y microondas. Todos estos materiales se han aplicado a la eliminación de NH3. Por otro lado se estudió la obtención de adsorbentes a partir de un lodo mezclado con distintas proporciones de cenizas volantes en un horno microondas. Estos materiales presentan un desarrollo de la porosidad limitado, y han sido empleados para la eliminación de H2S.

El aumento de la cantidad de lodos y las dificultades inherentes a su aplicación agrícola y/o disposición en vertederos, hace necesario encontrar nuevas alternativas para su gestión. A nivel europeo, hoy en día se tiende hacia la aplicación de tratamientos térmicos (incineración, pirólisis y gasificación) que permiten una valoración energética de los lodos, si bien generan un residuo sólido que sigue siendo necesario gestionar. El problema medioambiental provocado por (malos) olores resulta difícil de abordar de una manera genérica, teniendo en consideración la propia naturaleza del olor y sus posibles causas. Los olores en las EDARs son provocados básicamente por la degradación de la materia orgánica en condiciones anaeróbicas y se detectan en todas las operaciones unitarias en diferentes niveles de concentración. Esta tesis incidiendo en ambos aspectos, tiene por objeto investigar la valorización de lodos como materiales precursores de adsorbentes/ catalizadores para la eliminación de olores en el entorno de las EDARs, maximizando la reutilización de los lodos.Para la realización de los experimentos se han seleccionado lodos procedentes de tres EDARs situadas en la región de Girona (SC, SB, SL) que difieren en cuanto al tratamiento de los lodos. Ambas muestras han sido caracterizadas con el fin de determinar las diferencias más importantes en los lodos de partida. Los parámetros de caracterización incluyen el análisis de composición química (análisis elemental e inmediato, determinación contenido en cenizas, medida pH, DRX, FT-IR, SEM / EDX) así como análisis de superficie (adsorción de N2 y CO2). En primer lugar los lodos caracterizados han sido sometidos a diferentes tratamientos térmicos de gasificación y pirólisis y los adsorbentes/ catalizadores obtenidos se han probado como adsorbentes para la eliminación de H2S. Como consecuencia de este estudio, se ha desechado el uso de uno de lodos (SC) puesto que se obtenían resultados muy similares a (SB), a continuación el estudio se centró en el lodo de SL. Con este objetivo se han preparado 12 muestras 6 de ellas pirolizadas y 6 gasificadas en el rango de temperaturas que comprende 600-1100 ºC. Posteriormente las muestras han sido caracterizadas y se ha determinado la capacidad de eliminación (x/M) del H2S. Los resultados muestran que hemos sido capaces de obtener unos materiales que si bien, presentan un bajo desarrollo de porosidad dan lugar a valores de capacidades de eliminación elevados y comparables a carbones y materiales adsorbentes comerciales (Centaur, Sorbalit). Las elevadas eficiencias de eliminación se atribuyen básicamente a la presencia de especies catalíticamente activas tales como los óxidos mixtos de calcio y hierro determinados por DRX en las muestras tratadas térmicamente. El segundo bloque de resultados se centra la mejora de las propiedades texturales de estos materiales adsorbentes. Con este objetivo se llevaron acabo procesos de activación física con CO2 y química con H3PO4 e hidróxidos alcalinos (NaOH y KOH), que hasta el momento no se había probado con este tipo de precursores. Los resultados indican que la activación física (CO2) y química (H3PO4) no son unos buenos métodos para la obtención de adsorbentes altamente porosos con este tipo de materia prima bajo las condiciones probadas, sin embargo la activación con hidróxidos alcalinos da lugar a materiales adsorbentes con superficies específicas de hasta 1600 m2g-1. En el caso de la activación con hidróxidos, tanto el incremento de la relación agente activante/ precursor como el incremento de la temperatura producen un descenso del rendimiento, al mismo tiempo que incrementan el valor de SBET.Los materiales resultantes de la activación con hidróxidos alcalinos se han probado como adsorbentes/ catalizadores para la eliminación de H2S. Los resultados indican que un incremento del área superficial no es indicativo de un aumento de la capacidad de eliminación dada la naturaleza ácida de estos materiales obtenidos. Con el fin de contrarrestar el efecto ácido de estos materiales se han realizado los mismos ensayos añadiendo NaOH al lecho de reacción llegando a valores de x/M de hasta 450 mgg-1. Posteriormente también se han realizado ensayos de eliminación de NH3 con algunas de estas muestras, y los resultados obtenidos de x/M son del orden de carbones activados comerciales. Los materiales adsorbentes obtenidos tras la activación con hidróxidos alcalinos se convierten en materiales muy atractivos para ser utilizados como adsorbentes/ catalizadores de múltiples contaminantes (COVs, Hg...). / During the last years there has been an increase in the number of wastewater treatment plants arising after the implementation of regulatory policies focused on sustainable development of contemporary societies. A large quantity of sewage sludge is produced and in addition, some traditional disposal routes are coming under pressure and others are being phased out. Therefore, it is necessary to seek cost-effective and innovate solutions to the problem incurred by sewage sludge disposal. Nowadays, the tendency in Europe is to use this residue to obtain energy by thermal treatments, such as incineration, pyrolysis and gasification, though during this treatment a residue that needs to be disposed is generated.Furthermore, the environmental problems prompted by odors are difficult to solve take considering the different origin and reasons for these bad smells. Bad smell in waste water treatment plants is produced basically by organic matter degradation. This thesis takes into account these two aspects. The aim of this work focuses on the revalorization of sewage sludge to obtain / prepare adsorbents / catalysts from various sewage-based precursors and their application in H2S and in NH3 abatement at ambient temperature. These two latter compounds are paradigmatic in odor related problems.The sewage sludge samples used in this study were obtained from three Spanish WWTPs located in Girona (SC, SB, SL). The influent of these selected facilities is mainly of domestic origin and differs in sludge treatment schemes. A detailed characterization of the solids under consideration is carried out, as a purpose to define the main differences. The techniques used to characterize precursors include chemical characterization (elemental analysis, ash content, pH determination, DRX, FT-IR, SEM / EDX), as well as their porosity characterization (physical adsorption of N2 and CO2).In the first part of the study we focused on dried samples that were subjected to different thermal treatments such as pyrolysis and gasification at different temperatures. The adsorbents/catalysts obtained were used for H2S removal. Afterwards, 12 samples were prepared from SL, 6 of them gasified between 600 - 1100 ºC and 6 pyrolysed at the same temperatures. The samples were characterized and used as an adsorbents for H2S removal. The results shown that we were able to obtain adsorbents with high removal efficiencies despite their low porosity development. These adsorption capacities values (x/M) are in the same range or even higher than x/M values from commercial active carbons (Centaur, Sorbalit). These high x/M values have been prompted to catalytic species such as dicalcium ferrite, identified by XRD.The second part of the study was focused on the preparation of adsorbents from these sewage sludge-based precursors (SB, SL) using different activation processes. Specifically, physical activation with CO2, H3PO4 activation and alkaline hydroxide activation were explored. It is worth noticing that, as far as we know, there are no previous studies in the literature dealing with the activation of sewage sludge by alkaline hydroxides (NaOH or KOH), whereas CO2 and H3PO4 have been scarcely used for the activation of this precursor. The results of the textural characterization of the materials prepared from physical activation by CO2 and chemical activation by H3PO4 show that, these precursors are not a suitable for the preparation of adsorbents by these two methods. Nevertheless, chemical activation by alkaline hydroxides can be a suitable method to develop porosity and surface areas higher than 1600 m2g-1 can be obtained from both sewage sludge precursors (SB, SL). An increase in the hydroxide: precursor ratio leads to an enhancement of the adsorption capacity of the adsorbents. The resultant materials were tested as adsorbents/catalyst for H2S abatement. The results shown that we are been able to obtain adsorbents from sludge-based materials with high surface areas but with relatively low adsorption capacities as a consequence of its acidic nature. NaOH was added to the adsorption bed to counteract the acidic nature of these materials. The x/M values obtained are higher than 450 mgg-1. In addition, some of these materials were used for NH3 removal being the results obtained comparable to those for commercial activated carbons x/M values, tested under similar experimental conditions. These "new" activated materials can be used as adsorbents for many environmental applications such as VOC, Hg removal, etc.