Estudio de la relación entre las características químicas del licor de mezcla en Biorreactores de Membrana y su correlación con las resistencias a la filtración

Los biorreactores de membrana (BRM) (reactor biológico + MF/UF) incluyen las tecnologías de membrana. La aplicación de estas tecnologías a los BRM permite la separación del licor de mezcla (fango) y el agua depurada. El principal inconveniente de los BRM es el ensuciamiento o fouling de las membranas. En el BRM, los elementos que suelen producir el ensuciamiento son principalmente materiales coloidales o sustancias poliméricas extracelulares (EPS). El fin de la presente tesis de máster es estudiar el ensuciamiento de las membranas generado por las sustancias poliméricas extracelulares (EPS) por medio de la determinación de las resistencias a la filtración. Hoy en día no existe ningún protocolo normalizado para la extracción de las EPS y análisis de las mismas, habiéndose probado varios métodos, tanto de extracción como de análisis.Zuriaga Agustí, E. (2010). Estudio de la relación entre las características químicas del licor de mezcla en Biorreactores de Membrana y su correlación con las resistencias a la filtración. http://hdl.handle.net/10251/11417Archivo delegad

Influencia de las características físicas y químicas del licor de mezcla en Bioreactores de Membrana y su correlación con los parámetros de operación en aguas residuales urbanas e industriales

In this Doctoral Thesis the study of the influence of the operating parameters of the activated sludge process on the physical and chemical characteristics of the mixed liquor, from different membrane bioreactors (MBR), has been carried out. In addition, an optical characterization of the mixing liquor has been performed. In order to achieve the above mentioned aim, samples of the mixed liquor from an MBR treating municipal wastewater were first analysed and then, the characteristics of two MBR mixed liquors treating the leachates from two treatment plants of the organic fraction of municipal solid waste (OFMSW) were evaluated. It is noteworthy that the difference between the two industrial MBR lies on the feeding (inlet) to the MBR, which is determined by the treatment performed to the OFMSW, since one of them consists of a wet anaerobic digestion (MBR-LS) and the other of a dry anaerobic digestion (MBR-HS), so that the latter leachate contains higher concentration of suspended solids in its composition. For the chemical characterization of the mixture liquor, the extracellular polymeric substances (EPS) have been analysed. EPS are formed by the sum of extracted extracellular polymeric substances (eEPS) and soluble microbial products (SMP). These substances are considered the main cause of membranes fouling in MBRs and are basically formed by proteins and polysaccharides, which can be both attached to the cell wall and outside the cell, in form of eEPS or SMP. Regarding the physical characterization, in particular it has been analysed and studied the effect on the membrane fouling of the total and volatile suspended solids, the viscosity, the capillary suction time and the particle size, measured through the resistance to filtration. Finally, in the municipal MBR, cell viability with epifluorescence microscopy has been studied, as well as the main components of EPS have been stained by two different methods. In addition, a statistical study has evaluated the effect of the main operating parameters of the MBR on the characterization parameters of the mixed liquor. By means of least squares regression, the operational parameters that influence SMP production in industrial MBR have been studied. The study was completed by evaluating the fouling of an ultrafiltration membrane with proteins extracted from EPS and subsequently purified with ammonium sulphate at different pH values. To this end, different synthetic proteins (bovine serum albumin, casein, haemoglobin and lysozyme) were first analysed and then compared with the proteins extracted from the mixed liquor. Membrane fouling with purified eEPS proteins has also been studied along with sodium alginate added in the same concentration as the proteins. The results obtained demonstrate, firstly, that SMP play an important role in the membrane fouling. The concentration of proteins has been considerably higher than that of carbohydrates both in SMP and in eEPS, although SMP influenced to a greater extent on the filtration of the activated sludge. In addition, it is shown that bacteria under stress conditions, caused for example by increase in conductivity, increase the production of SMP, and therefore, membrane fouling increases. On the other hand, it is concluded that a low hydraulic retention time favours a high carbohydrates concentration and consequently drives to an increase in the viscosity and capillary suction time, also increasing the membrane fouling.En la presente Tesis Doctoral se ha llevado a cabo el estudio de la influencia de los parámetros de operación del proceso de fangos activos en las características físicas y químicas de los licores de mezcla, procedentes de diferentes biorreactores de membrana (MBR). Además, se ha realizado una caracterización óptica del licor de mezcla. Para ello, en primer lugar se tomaron muestras del licor de mezcla de un MBR que trata aguas residuales urbanas y, a continuación, se evaluaron las características de los licores de mezcla de dos MBR que tratan los lixiviados procedentes de dos plantas de tratamiento de la fracción orgánica de los residuos sólidos urbanos (FORSU). Cabe destacar que la diferencia entre los dos MBR industriales radica en la alimentación (afluentes) al MBR, que viene determinada por el tratamiento que se realiza a la FORSU, ya que uno de ellos consiste en una digestión anaerobia en vía húmeda (MBR-LS) y, el otro, en una digestión anaerobia en vía seca (MBR-HS), por lo que este último lixiviado contiene mayor concentración de sólidos en suspensión en su composición. Para la caracterización química del licor de mezcla, se han analizado las sustancias poliméricas extracelulares (EPS), formadas por la suma de las sustancias poliméricas extracelulares extraídas (eEPS) y los productos solubles microbianos (SMP). Estas sustancias se consideran las principales causantes del ensuciamiento de las membranas del MBR y están formadas básicamente por proteínas y polisacáridos, los cuales pueden estar tanto adheridos a la pared celular como fuera de la célula, en forma de eEPS o SMP. En cuanto a la caracterización física, en concreto se ha analizado y estudiado el efecto en el ensuciamiento de las membranas de los sólidos en suspensión totales y volátiles, la viscosidad, el tiempo de succión capilar y el tamaño de partícula, medido a través de las resistencias a la filtración. Finalmente, en el MBR urbano se ha estudiado la viabilidad celular con microscopía de epifluorescencia, así como se han teñido para su caracterización óptica los principales componentes de las EPS por dos métodos distintos. Además, mediante un estudio estadístico se ha evaluado el efecto de los principales parámetros de operación de los MBR sobre los parámetros de caracterización del licor de mezcla. Mediante regresión por mínimos cuadrados se han estudiado los parámetros operacionales que influyen en la producción de SMP en los MBR industriales. El estudio se ha completado evaluando el ensuciamiento de una membrana de ultrafiltración con proteínas extraídas de las EPS y posteriormente purificadas con sulfato amónico, a diferentes valores de pH. Para ello, en primer lugar se han caracterizado diferentes proteínas sintéticas (albúmina de suero bovino, caseína, hemoglobina y lisozima) para compararlas con las proteínas extraídas del licor de mezcla. También se ha estudiado el ensuciamiento de la membrana con las proteínas purificadas de las eEPS junto con alginato de sodio en la misma proporción. Los resultados obtenidos demuestran en primer lugar que los SMP juegan un papel importante en el ensuciamiento de las membranas. Tanto en su composición como en la de las eEPS, la concentración de proteínas determinada ha sido considerablemente mayor que la de carbohidratos, si bien éstos influyen incluso en mayor medida en la filtrabilidad del fango activo. Además, se demuestra que las bacterias bajo condiciones de estrés, causado por ejemplo por aumento de conductividad, aumentan la producción de SMP, y por tanto, se incrementa el ensuciamiento de las membranas. Por otro lado, se concluye que un tiempo de retención hidráulico bajo favorece una concentración elevada de carbohidratos y consecuentemente provoca un aumento de la viscosidad y el tiempo de succión capilar, aumentando también el ensuciamiento de la membrana.En la present Tesi Doctoral s'ha dut a terme l'estudi de la influència dels paràmetres d'operació del procés de fangs actius en les característiques físiques i químiques de licors de mescla, procedents de diferents biorreactors de membrana (MBR). A més, s'ha realitzat una caracterització òptica del licor de mescla. Per a això, en primer lloc es van prendre mostres del licor de mescla d'un MBR que tracta aigües residuals urbanes i, a continuació, es van avaluar les característiques dels licors de mescla de dos MBR que tracten els lixiviats procedents de dues plantes de tractament de la fracció orgànica dels residus sòlids urbans (FORSU). Cal destacar que la diferència entre els dos MBR industrials radica en l'alimentació (afluents) al MBR, que ve determinada pel tractament que es realitza a la FORSU, ja que un d'ells consisteix en una digestió anaeròbia en via humida (MBR-LS) i, l'altre, en una digestió anaeròbia en via seca (MBR-HS), per la qual cosa este últim lixiviat conté major concentració de sòlids en suspensió en la seua composició. Per a la caracterització química del licor de mescla, s'han analitzat les substàncies polimèriques extracel¿lulars (EPS), formades per la suma de les substàncies polimèriques extracel¿lulars extretes (eEPS) i els productes solubles microbians (SMP). Estes substàncies es consideren les principals causants de l'embrutiment de les membranes del MBR i estan formades bàsicament per proteïnes i polisacàrids, els quals poden estar tant adherits a la paret cel¿lular com fora de la cèl¿lula, en forma d'eEPS o SMP. Quant a la caracterització física, en concret s'ha analitzat i estudiat l'efecte en l'embrutiment de les membranes dels sòlids en suspensió totals i volàtils, la viscositat, el temps de succió capil¿lar i la grandària de partícula, mesurat a través de les resistències a la filtració. Finalment, en el MBR urbà s'ha estudiat la viabilitat cel¿lular amb microscòpia d'epifluorescència, així com s'han tenyit per a la seua caracterització òptica els principals components de les EPS per dos mètodes distints. A més, per mitjà d'un estudi estadístic s'ha avaluat l'efecte dels principals paràmetres d'operació dels MBR sobre els paràmetres de caracterització del licor de mescla. Per mitjà de regressió per mínims quadrats s'han estudiat els paràmetres operacionals que influeixen en la producció de SMP en els MBR industrials. L'estudi s'ha completat avaluant l'embrutiment d'una membrana d'ultrafiltració amb proteïnes extretes de les EPS i posteriorment purificades amb sulfat amònic, a diferents valors de pH. Per a això, en primer lloc s'han caracteritzat diferents proteïnes sintètiques (albúmina de sèrum boví, caseïna, hemoglobina i lisozima) per a comparar-les amb les proteïnes extretes del licor de mescla. També s'ha estudiat l'embrutiment de la membrana amb les proteïnes purificades de les eEPS junt amb alginat de sodi en la mateixa proporció. Els resultats obtinguts demostren en primer lloc que els SMP juguen un paper important en l'embrutiment de les membranes. Tant en la seua composició com en la de les eEPS, la concentració de proteïnes determinada ha sigut considerablement major que la de carbohidrats, si bé estos influeixen inclús en major grau en la filtrabilidad del fang actiu. A més, es demostra que els bacteris baix condicions d'estrès, causat per exemple per augment de conductivitat, augmenten la producció de SMP, i per tant, s'incrementa l'embrutiment de les membranes. D'altra banda, es conclou que un temps de retenció hidràulic baix afavoreix una concentració elevada de carbohidrats i conseqüentment provoca un augment de la viscositat i el temps de succió capil¿lar, augmentant també l'embrutiment de la membrana.Zuriaga Agustí, E. (2017). Influencia de las características físicas y químicas del licor de mezcla en Bioreactores de Membrana y su correlación con los parámetros de operación en aguas residuales urbanas e industriales [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/90512TESI

Nutraceutical profiles of apricots (Prunus armeniaca L.) as a source of fruit quality traits for breeding

Aim of study: In a social context of increasing concern about healthy diets, the development of new varieties with enhanced content in nutraceutical compounds is an important objective of the fruit breeding programs currently developed. In this sense, apricot is a fruit crop very appreciated by consumers worldwide due to its organoleptic characteristics, but also plays an important role in human nutrition due to its content of phytocompounds as sugars, organic acids, vitamins and polyphenols. Area of study: The identification of sources of variation for these traits could be useful for apricot breeding worldwide. Material and methods: New selections from the apricot breeding program carried out at the Instituto Valenciano de Investigaciones Agrarias (IVIA, Spain) and traditional varieties have been analysed aimed at identifying sources of genetic variation for fruit quality. For this purpose, sugar content, organic acids and ascorbic acid were studied during three crop years. Main results: Results revealed sucrose and glucose as the major sugars, malic and citric acid as the main organic acids, and diverse ascorbic acid content among the cultivars studied. Research highlights: Some accessions point as potential sources to increase fruit quality. In addition, the study showed that apricot peel is an excellent source of nutraceutical compounds. Moreover, this study opens up new possibilities to study the genetic control of these traits in apricot in the future

Physical mapping of a pollen modifier locus controlling self-incompatibility in apricot and synteny analysis within the Rosaceae

locus products (S-RNase and F-box proteins) are essential for the gametophytic self-incompatibility (GSI) specific recognition in . However, accumulated genetic evidence suggests that other -locus unlinked factors are also required for GSI. For instance, GSI breakdown was associated with a pollen-part mutation unlinked to the -locus in the apricot ( L.) cv. 'Canino'. Fine-mapping of this mutated modifier gene (-locus) and the synteny analysis of the -locus within the Rosaceae are here reported. A segregation distortion loci mapping strategy, based on a selectively genotyped population, was used to map the -locus. In addition, a bacterial artificial chromosome (BAC) contig was constructed for this region using overlapping oligonucleotides probes, and BAC-end sequences (BES) were blasted against Rosaceae genomes to perform micro-synteny analysis. The -locus was mapped to the distal part of chr.3 flanked by two SSR markers within an interval of 1.8 cM corresponding to similar to 364 Kb in the peach ( L. Batsch) genome. In the integrated genetic-physical map of this region, BES were mapped against the peach scaffold_3 and BACs were anchored to the apricot map. Micro-syntenic blocks were detected in apple ( x Borkh.) LG17/9 and strawberry ( L.) FG6 chromosomes. The -locus fine-scale mapping provides a solid basis for self-compatibility marker-assisted selection and for positional cloning of the underlying gene, a necessary goal to elucidate the pollen rejection mechanism in . In a wider context, the syntenic regions identified in peach, apple and strawberry might be useful to interpret GSI evolution in Rosaceae

Polyphenol content in apricot fruits

Apricot (Prunus armeniaca L.) species is one of the most important Mediterranean fruits. The fruits are important in the diet of Asian and Mediterranean countries in which the apricot is used as fresh and dried fruit, being an important source of nutrients. Despite of the amount of genetic resources and diversity studies available into the species, there are a few studies focused on fruit quality. Among the different compounds of fruit quality, polyphenols are classified as the most abundant antioxidants in nature, being important as a source of health benefits as well as a potential source of natural products for the food industry. The important role of polyphenols in human nutrition, outline these compounds as the most relevant for defining fruit quality. In this study, the polyphenol content on fruits from different apricot varieties included elite cultivars and hybrids from the IVIA breeding program have been compared for identifying the genotypes with relevant contribution to fruit quality. The most important compounds obtained in terms of quantity were: phenolic acids and flavonoids. Results identified the PPV resistant cultivar ‘Goldrich’ as the best cultivar for increasing the content of antioxidants in the varieties of the breeding program

Sludge reduction by uncoupling metabolism: SBR tests with para-nitrophenol and a commercial uncoupler

Nowadays cost reduction is a very important issue in wastewater treatment plants. One way, is to minimize the sludge production. Microorganisms break down the organic matter into inorganic compounds through catabolism. Uncoupling metabolism is a method which promote catabolism reactions instead of anabolism ones, where adenosine triphosphate synthesis is inhibited. In this work, the influence of the addition of para-nitrophenol and a commercial reagent to a sequencing batch reactor (SBR) on sludge production and process performance has been analyzed. Three laboratory SBRs were operated in parallel to compare the effect of the addition of both reagents with a control reactor. SBRs were fed with synthetic wastewater and were operated with the same conditions. Results showed that sludge production was slightly reduced for the tested para-nitrophenol concentrations (20 and 25 mg/L) and for a LODOred dose of 1 mL/day. Biological process performance was not influenced and high COD removals were achieved. (C) 2016 Elsevier Ltd. All rights reserved.This work was supported by Universitat Politecnica de Valencia (Project reference: PAID-05-12).Zuriaga Agustí, E.; Mendoza Roca, JA.; Bes Piá, MA.; Alonso Molina, JL.; Amoros Muñoz, I. (2016). Sludge reduction by uncoupling metabolism: SBR tests with para-nitrophenol and a commercial uncoupler. Journal of Environmental Management. 182:406-411. https://doi.org/10.1016/j.jenvman.2016.07.100S40641118

Reduction of the sludge production in a sequencing batch reactor by addition of chlorine dioxide: Influence on the process performance

Costs reduction in the activated sludge process in municipal wastewater treatment plants (MWWTPs) has nowadays become of paramount important due to the current economic situation. One of the saving measures that are being currently studied is the reduction of sludge production. In this work, the influence of the addition of chlorine dioxide to a sequencing batch reactor (SBR) on the sludge production and on the process performance has been studied. After preliminary jar-tests to select the ClO2 concentration range to be studied, two series of experiences were carried out. In the first series of experiments two laboratory SBRs were operated in parallel to test the effect of three different ClO2 doses. In the second one, three laboratory SBRs were operated in parallel to go on studying the influence of the chlorine dioxide addition on the SBRs performance and to compare two different dosing strategies (directly to the reactor and mixing the oxidant with a part of the sludge in a separated tank). SBRs treated simulated municipal wastewater and they were operated with the same operating strategy. Results showed that doses of 5 and 10 mg ClO2/gTSS entailed severe deterioration of the biological process, meanwhile the dose of 2 mg ClO2/gTSS hardly decreased the COD removal performance, implying a reduction of sludge production of 20.2%. An increase of the dose up to 2.5 mg ClO2/gTSS increased the reduction of the sludge production up to 43.4%, when the oxidant was added directly to the reactor in the anoxic reaction phase.Authors thank Fomento Agricola Castellonense S.A. (FACSA) for the support in the project.Zuriaga Agusti, E.; Garrido Mauri, G.; Mendoza Roca, JA.; Bes Piá, MA.; Alonso Molina, JL. (2012). Reduction of the sludge production in a sequencing batch reactor by addition of chlorine dioxide: Influence on the process performance. Chemical Engineering Journal. 209:318-324. doi:10.1016/j.cej.2012.08.004S31832420

Búsqueda de interactores para la caracterización de los genes ParPMC implicados en la resistencia a Sharka en albaricoquero

La enfermedad de la Sharka, causada por el potyvirus Plum pox virus (PPV) es el factor más limitante para el cultivo de frutales de hueso. El desarrollo de variedades resistentes se ha propuesto como la mejor solución para el control de esta enfermedad. Sin embargo, se conocen pocas fuentes de resistencia que puedan ser de utilidad para su incorporación a los programas de mejora. En el caso de albaricoque se identificaron una decena de variedades norteamericanas que muestran resistencia a PPV. Combinando datos genéticos y genómicos propusimos a los genes ParPMC1 y ParPMC2 como genes de susceptibilidad cuyo silenciamiento confiere resistencia a PPV

Facebook usage by students in higher education

[EN] In this paper I measure first year student Facebook usage as part of a broader PhD study into the influence of social media usage on the success of students in higher education. A total of 906 students were asked to complete 3 surveys on Facebook usage with their peers, for two consecutive years (2011-2012 and 2012-2013). The different purposes for Facebook usage, in addition to whether or not students used (self-created) Facebook-groups, were measured and the relationship between the use of pages compared to the purpose of Facebook usage. This resulted in significant correlations between the purpose of Facebook usage and the use of different pages, as well as correlations between the purpose and use of different pages. This study hereby explores the variation in student Facebook usage and provides valuable insight into the potential value of Facebook for students in an educational setting, without the interference of teachers. It is also the next logical step in revising existing integration and engagement theories that predict student successin higher education in contemporary society.Wesseling, N. (2015). Facebook usage by students in higher education. En 1ST INTERNATIONAL CONFERENCE ON HIGHER EDUCATION ADVANCES (HEAD' 15). Editorial Universitat Politècnica de València. 593-599. https://doi.org/10.4995/HEAd15.2015.395OCS59359

Insights of Phenolic Pathway in Fruits: Transcriptional and Metabolic Profiling in Apricot (Prunus armeniaca)

There is an increasing interest in polyphenols, plant secondary metabolites, in terms of fruit quality and diet, mainly due to their antioxidant effect. However, the identification of key gene enzymes and their roles in the phenylpropanoid pathway in temperate fruits species remains uncertain. Apricot (Prunus armeniaca) is a Mediterranean fruit with high diversity and fruit quality properties, being an excellent source of polyphenol compounds. For a better understanding of the phenolic pathway in these fruits, we selected a set of accessions with genetic-based differences in phenolic compounds accumulation. HPLC analysis of the main phenolic compounds and transcriptional analysis of the genes involved in key steps of the polyphenol network were carried out. Phenylalanine ammonia-lyase (PAL), dihydroflavonol-4-reductase (DFR) and flavonol synthase (FLS) were the key enzymes selected. Orthologous of the genes involved in transcription of these enzymes were identified in apricot: ParPAL1, ParPAL2, ParDFR, ParFLS1 and ParFLS2. Transcriptional data of the genes involved in those critical points and their relationships with the polyphenol compounds were analyzed. Higher expression of ParDFR and ParPAL2 has been associated with red-blushed accessions. Differences in expression between paralogues could be related to the presence of a BOXCOREDCPAL cis-acting element related to the genes involved in anthocyanin synthesis ParFLS2, ParDFR and ParPAL2