Reverse osmosis membrane composition, structure and performance modification by bisulphite, iron(III), bromide and chlorite exposure

Reverse osmosis (RO) membrane exposure to bisulphite, chlorite, bromide and iron(III) was assessed in terms of membrane composition, structure and performance. Membrane composition was determined by Rutherford backscattering spectrometry (RBS) and membrane performance was assessed by water and chloride permeation, using a modified version of the solution-diffusion model. Iron(III) dosage in presence of bisulphite led to an autooxidation of the latter, probably generating free radicals which damaged the membrane. It comprised a significant raise in chloride passage (chloride permeation coefficient increased 5.3–5.1 fold compared to the virgin membrane under the conditions studied) rapidly. No major differences in terms of water permeability and membrane composition were observed. Nevertheless, an increase in the size of the network pores, and a raise in the fraction of aggregate pores of the polyamide (PA) layer were identified, but no amide bond cleavage was observed. These structural changes were therefore, in accordance with the transport properties observed.Peer ReviewedPostprint (author's final draft

Telepathology and Optical Biopsy

The ability to obtain information about the structure of tissue without taking a sample for pathology has opened the way for new diagnostic techniques. The present paper reviews all currently available techniques capable of producing an optical biopsy, with or without morphological images. Most of these techniques are carried out by physicians who are not specialized in pathology and therefore not trained to interpret the results as a pathologist would. In these cases, the use of telepathology or distant consultation techniques is essential

Retos metodológicos para estudiar la vulnerabilidad demográfica y residencial a nivel intraurbano ante los cambios en las fuentes estadísticas habituales.

Los estudios geográficos aplicados a escalas de detalle se encuentran muy condicionados por la disponibilidad de fuentes de referencia. Esto es determinante en este momento, en el que asistimos a cambios en las fuentes estadísticas oficiales, que pueden poner en riesgo la continuidad de investigaciones representativas a nivel intraurbano. Se afianza, así, un período idóneo para explorar fuentes alternativas que implicarán necesariamente nuevas pautas metodológicas. En este marco, el artículo apuesta por nuevos planteamientos para la determinación de los patrones espaciales de la población vulnerable a nivel intraurbano, a partir de datos disponibles y observables de edificación y entorno. Tras una aproximación a nivel de sección censal, el estudio se centra en modelizar la vulnerabilidad demográfica y residencial a nivel de edificio, mediante métodos downscaling. Esta metodología puede ser exportada a otras ciudades españolas e, incluso, a otros países con una ligera adaptación

Reversibility of fouling on ultrafiltration membrane by backwashing and chemical cleaning: differences in organic fractions behaviour

Membrane fouling is an inherent phenomenon in ultrafiltration (UF) membrane processes, making it necessary to periodically perform backwashes (BW) and chemical cleanings in place (CIP) to restore the initial permeability of the membrane. The objective of this study was (1) to explore systematically the effect of distinct BW-related variables (BW transmembrane pressure, duration, frequency and composition) on the reversibility of UF membrane fouling and on the permeate quality (in terms of total organic carbon, turbidity and UV absorbance) over successive filtration/BW cycles; and (2) to identify which organic fractions were most removed by the membrane and, of these, which were most detached after BW, alkaline and oxidant CIP and acid CIP episodes. For this purpose, a bench-scale outside-in hollow fibre module operated under dead-end filtration mode at constant transmembrane pressure and treating settled water from a drinking water treatment plant was employed. Dissolved organic carbon fractionation was performed by high-performance size-exclusion chromatography. Results showed that, in general, the more intensive the BW was (in terms of high transmembrane pressure, shortened frequency and prolonged duration) the more effective it was in removing fouling from the membrane. Concerning the composition of the water used for the BW, the addition of NaClO led to maximum fouling reversibility, closely followed by the combination of NaOH+NaClO, while citric acid and NaOH contributed little compared to water alone. However, results also showed that irreversible fouling was never completely avoided whatever the BW regime applied, leading to a gradual increase in the total resistance over time. Larger differences in the behaviour of the different organic fractions were observed. UF membrane preferentially retained the heaviest fraction of biopolymers (BP), while the intermediate fraction of humic substances (HS) was removed at a lower percentage and the lighter fractions seemed to entirely pass through the UF membrane. The successive application of BW and CIPs resulted in the detachment from the membrane of a significant percentage of the retained BP, whereas only a modest percentage of the retained HS.Peer ReviewedPostprint (author's final draft

Composition and reversibility of fouling on low-pressure membranes in the filtration of coagulated water: insights into organic fractions behaviour

The primary problem for the application of microfiltration (MF) and ultrafiltration (UF) membrane technology is membrane fouling. Such is the case that understanding membrane fouling has become one of the major factors driving MF and UF membrane technology for- ward. Nevertheless, identifying the constituents that most contribute to membrane fouling 20 and quantifying how they are detached when backwashing (BW) and cleaning-in-place (CIP) are applied still remains a challenging task. The aim of the present study was to quan- tify membrane fouling development during filtration and membrane fouling detachment during BW and CIP in terms of membrane permeability changes and masses of inorganic and organic constituents accumulated on the membrane. The study was conducted using 25 bench-scale MF and UF modules fed with coagulated and settled water coming from a drinking water treatment plant and operated under dead-end and cross-flow operation modes. The experiments consisted inconsecutive permeation (20 min) alternated with BW with permeate water (1.0 min) (periodically chemically assisted with NaClO and NaOH) and followed by a two-stage CIP consisting first in an oxidising and basic step (NaClO and 30 NaOH) and second in an acidic step (citric acid). Feed, permeate, retentate (when present) and cleaning discharge streams were monitored for turbidity, total and dissolved organic carbon (TOC and DOC, respectively), UV 254 and inorganic ions (Al, Fe, P). DOC was frac- tionated by high-performance size exclusion chromatography to gain insight into the beha- viour of the different organic fractions. Results showed that both MF and UF membranes 35 successfully removed turbidity, Al and Fe, whereas UV 254 was moderately removed and TOC and DOC poorly removed, with removal percentages higher for UF than for MF. With regard to the organic fractions, the largest molecular weight compounds were moderately removed while the smallest organic fractions seemed to totally permeate through both membranes. The results also showed that foulants were poorly washed out from thePeer ReviewedPostprint (author's final draft

Projecte de millora la intersecció LV-5223 a Altron mitjançant una rotonda

L’objecte del projecte és la definició i valoració dels treballs necessaris per a millorar la intersecció de la LV-5223 a Altron, ja existent. Les modificacions de la intersecció consisteixen bàsicament en la construcció d’una rotonda per tal de resoldre d’una forma segura, còmoda i eficaç la intersecció dels diferents recintes

Substitution of conventional pre-treatment units by membrane based processes in drinking water treatment

This thesis focused on the feasibility of substituting, partially or totally, drinking water treatment plant (DWTP) conventional pre-treatment by membrane based units, in particular by ultrafiltration (UF). For such purpose, bench and pilot scale tests with natural water were conducted, first, to address the technical feasibility and, second, to optimize its performance in order to determine whereas the proposed scheme was competitive from hydraulic and quality perspectives with the current conventional pre-treatment. Moreover, tailored microbes based tests were defined to assess its proper functioning and reliability, and additional advantages related to direct UF besides those purely related to the pre-treatment unit were investigated. The case study selected was Sant Joan Despí DWTP (Barcelona, Spain) due to its particularities: it treats Llobregat River water, which is a highly variable water resource in terms of quality and quantity, and it is a complex multistage system. As a result, this study covered a wide range of conditions and the technology under consideration could be pushed to its limits. Results showed that direct UF of raw river water was a competitive alternative to dioxichlorination, coagulation/flocculation, settling and sand filtration. The pilot plant was able to continuously treat raw river water during 2 years, independently of its quality (e.g. turbidity > 1,000 NTU), delivering water of high and stable quality, both physico-chemically and microbiologically. In terms of pre-treated water quality, most of the physico-chemical parameters monitored presented lower values and variability in the direct UF scheme than in the conventional pre-treatment process. From a microbiological perspective, the direct UF scheme tested ensured an average removal of > 5 log10 units of bacteria and viruses greater than 60 nm. The highest water yields achieved ranged between 94.0%-94.7% in optimal conditions, involving 1 or 2 chemically enhanced backwashes (CEBs) per day, transmembrane pressure (TMP) below 1 bar, filtration fluxes of 40¿70 L/(m2¿h) and low reagents consumption. When a micro-coagulation previous to the UF was applied, the increase of the hydraulic resistance during filtration was decreased and stabilized, especially in winter, the hydraulic cleaning efficiency raised and the CEB frequency diminished. Since fouling indicators (SDI15 and MFI0.45) of the direct UF permeate were lower than those associated to the conventional pre-treatment, the subsequent reverse osmosis (RO) unit would require less chemical cleanings and thus, its lifetime would be extended. In addition to this, besides the economic savings associated to the significant reduction of reagents dosed within the direct UF scheme (chemical disinfectants and coagulants mainly), a minimization of risk of RO membrane degradation was demonstrated. Studies concerning the effects on physico-chemical and transport properties of RO membranes exposed to chemicals used within the conventional pre-treatment scheme but avoided in the direct UF treatment were also undertaken. An advanced characterisation of the exposed membranes enabled understanding the RO membranes performance changes with its composition and structure modification. The implementation of direct UF would imply the pre-treatment being a single membrane filtration step. This has advantages in terms of process complexity, space requirements, as well as avoidance of chemical based disinfectants dosage. Nevertheless, the preservation of its separating properties along time is of utmost importance, especially from a microbiological standpoint. Consequently, microbes based tailored tests aiming at assessing membrane integrity were defined and conducted periodically, to determine the removal capacity reliability of the pre-treatment scheme proposed in this thesis. Results showed that membrane integrity had not been compromised despite the challenging conditions that direct UF posed.Aquesta tesis s'ha centrat en l'estudi de la substitució, total o parcial, de l'etapa de pre-tractament d'estacions de tractament d'aigua potable (ETAPs) per processos de membrana, en particular per ultrafiltració (UF). Per a tal fi, es van realitzar experiments a nivell laboratori i pilot per, en primer lloc, avaluar la seva viabilitat tècnica, i en segon, optimitzar el seu funcionament per determinar així si l'esquema de tractament proposat era competitiu des d'un punt de vista hidràulic i de qualitat amb el pre-tractament convencional actual. A més, es van definir assajos per assegurar el seu correcte funcionament i fiabilitat, i es van identificar avantatges addicionals a les purament associades a l'etapa de pre-tractament. El cas d'estudi seleccionat va ser l'ETAP de Sant Joan Despí (Barcelona) degut a les seves particularitats: tracta aigua del riu Llobregat, que és un recurs altament variable en termes de qualitat i quantitat, i és un sistema multi-etapa complex. En conseqüència aquest estudi va cobrir un ampli rang de condicions i va permetre portar la tecnologia en qüestió a condicions límit. Els resultats vam mostrar que la UF directa d'aigua crua de riu és capaç de substituir, i resulta competitiva, amb la dioxicloració, coagulació/floculació, decantació i filtració per sorra. La planta pilot va ser capaç de tractar contínuament aigua crua durant 2 anys, independentment de la seva qualitat (ex. terbolesa d'entrada > 1000 NTU), produint aigua de qualitat alta i estable, tant fisicoquímicament com microbiològicament. La majoria dels paràmetres fisicoquímics avaluats van presentar valors inferiors i amb menor variabilitat en l'esquema d'UF directa que en el pre-tractament convencional. Des d'una perspectiva microbiològica, l'esquema d'UF directa avaluat va assegurar una eliminació > 5 log10 unitats de bactèries i virus de tamany superior a 60 nm. El rendiment hídric va oscil.lar entre 94.0-94.7% en condicions òptimes, requerint 1 o 2 contra rentats químics al dia, una pressió transmembrana per sota d'1 bar, fluxos de filtració entre 40-70 L/(m2.h) i un baix consum de reactius químics. En aplicar una micro-coagulació prèvia a la UF, l'increment de la resistència hidràulica durant la filtració va disminuir i es va estabilitzar, l'eficiència del contra rentat va augmentar, i la freqüència dels contra rentats químics va davallar. Degut a que els indicadors d'embrutiment (SDI15 i MFI0.45) del permeat d'UF directa van resultar inferiors als del pretractament convencional, és d'esperar que la unitat següent d'osmosis inversa (OI) precisi menys neteges químiques i per tant, la seva vida útil es prolongui. Addicionalment, a part de l'estalvi econòmic associat a la reducció significativa de reactius dosificats en l'esquema l'UF directa (desinfectants químics i coagulants principalment), es va demostrar una disminució del risc de degradació de les membranes d'OI. Es van dur a terme estudis avaluant els efectes de l'exposició de certs químics (dosificats en el pre-tractament convencional però no en l'UF directa) en les propietats fisicoquímiques i de transport de membranes d'OI. Una caracterització avançada va permetre relacionar els canvis de funcionament de les membranes d'OI amb els seus canvis de composició i d'estructura. La implementació de la UF directa implica que el pre-tractament consisteixi únicament en una etapa de filtració. Això suposa avantatges en termes de complexitat del procés, requeriments d'espai així com d'evitar l'ús de desinfectats químics. Tanmateix, la preservació de les seves propietats de separació al llarg del temps és de gran importància, sobretot des d'un punt de vista microbiològic. En conseqüència, es van definir i dur a terme periòdicament assajos en base a microorganismes per avaluar la integritat de la membrana d'UF directa. Els resultats van indicar que la integritat de la membrana d'UF s'havia preservat durant els 2 anys d'estudi, malgrat les condicions severes que la UF directa va suposa

Comparativa de soluciones destinadas a un proyecto

Antes de empezar un proyecto, es importante realizar un estudio de la situación y una propuesta de solución para enmarcar el trabajo y guiar al cliente en sus necesidades. De esto se trata este documento, un caso inspirado en el proyecto en el que he trabajado durante mis prácticas en everis. Un cliente busca la integración de una nueva funcionalidad en su plataforma y everis le quiere mostrar todas las posibilidades que le puede ofrecer para conseguir sus objetivos. El TFG se centra únicamente en el análisis previo al proyecto de integración de la solución pero con una particularidad: no se empieza una solución desde cero. Lo que hacemos es analizar dos activos ya desarrollados por la empresa y descubrir cómo encaja cada uno en el contexto del cliente y cuál es la mejor propuesta para él.Before starting a new project, it is important to work on a previous analysis of the client's situation and to make a proposal of how we see the solution in order to limit the project and to guide our clients through their necessities. This document focuses on that, it's a case inspired by a project I worked on during the internship in everis. Our client wants to add a new functionality to its website and everis works to show them all the possibilities they have to accomplish their objectives. This TFG is focused on the previous study of the project but it treats something remarkable: the solution we want to offer it's not started from the beginning. What we do it's to analyse two projects that were developed before in the company and we try to discover which one of them would be the most useful for our client.Abans de començar un projecte, és important realitzar un estudi de la situació y una proposta de solució prèvia per limitar el treball i ensenyar al nostre client quines opcions té. D'això es tracta el següent document, un cas inspirat en el projecte en el que treballava durant les meves pràctiques a everis. Un client cerca la integració d’una nova funcionalitat a la seva plataforma i everis treballa per oferir totes les possibilitats que pugui per aconseguir els objectius proposats. El TFG es centra en l’anàlisis previ al projecte de la integració però amb una particularitat: no es comença una solució des de zero. El que fem és analitzar dos actius ja desenvolupats per l’empresa y descobrir com encaixen en el context del client i quina és la millor proposta per la seva situació

An Embodied Spiritual Inquiry into the Nature of Human Boundaries: Outcomes of a Participatory Approach to Transpersonal Education and Research

Embodied spiritual inquiry (ESI) is a radical approach to integral and transpersonal education and research offered as a graduate course at the California Institute of Integral Studies (CIIS). Inspired by elements of participatory research and cooperative inquiry, ESI applies interactive embodied meditations to access multiple ways of knowing (e.g., somatic, vital, emotional, mental, contemplative) and mindfully inquire into collaboratively decided questions. This article presents the learning outcomes of an inquiry into the nature of human boundaries within and between co-inquirers, providing an example of how ESI is implemented in the classroom and can be used to study transpersonal subject matter. In particular, the study found that boundaries were experienced in terms of their dynamic effects rather than as static qualities, with a relationship between dissociation and overly firm boundaries, as well as a relationship between integration/merging and more varied combinations of firm and permeable boundaries. Other notable inquiry outcomes include the identification of (a) experiential qualities of the states of dissociation, merging, and integration; (b) a recursive relationship between fear and trust in the modulation of optimal interpersonal boundaries; and (c) the phenomenon of shared emergent experience between practitioners, which suggests the existence of an intersubjective transpersonal field

An Embodied Spiritual Inquiry into the Nature of Human Boundaries: Outcomes of a Participatory Approach to Transpersonal Education and Research

Embodied spiritual inquiry (ESI) is a radical approach to integral and transpersonal education and research offered as a graduate course at the California Institute of Integral Studies (CIIS). Inspired by elements of participatory research and cooperative inquiry, ESI applies interactive embodied meditations to access multiple ways of knowing (e.g., somatic, vital, emotional, mental, contemplative) and mindfully inquire into collaboratively decided questions. This article presents the learning outcomes of an inquiry into the nature of human boundaries within and between co-inquirers, providing an example of how ESI is implemented in the classroom and can be used to study transpersonal subject matter. In particular, the study found that boundaries were experienced in terms of their dynamic effects rather than as static qualities, with a relationship between dissociation and overly firm boundaries, as well as a relationship between integration/merging and more varied combinations of firm and permeable boundaries. Other notable inquiry outcomes include the identification of (a) experiential qualities of the states of dissociation, merging, and integration; (b) a recursive relationship between fear and trust in the modulation of optimal interpersonal boundaries; and (c) the phenomenon of shared emergent experience between practitioners, which suggests the existence of an intersubjective transpersonal field