No description available.

Abstract The removal of Natural Organic Matter (NOM) from water supplies is crucial for the provision of clean, safe drinking water. Lab-scale experiments have been extensively utilized in water treatment facilities to optimize this process. The most used lab-scale method is known as jar test. However, with emerging membrane filtration, lab-scale inline coagulation has been recently utilized to mimic the inline coagulation over membrane filtration in water treatment plants (WTPs).     This study aims to compare the jar test with inline coagulation micro pilot methods from different aspects, including the NOM removal, time, and cost needed for each process. Three case studies were conducted using different water sources in Sweden: Katrineholm, Mälaren, and Mjörn.     In the experiments conducted to find the optimal NOM removal condition, the inline coagulation micro pilot method outperforms the jar test in terms of removal efficiency. In the Katrineholm case, the micro pilot method with a coagulant dosage of 4.5mg/l Al at pH 6.7 achieved removal efficiencies of 63% for fluorescent dissolved organic matter (fDOM), whereas the jar test showed 60% for fDOM but with a significantly higher coagulant dosage (7mg/l) . In the Mälaren case, the micro pilot method using a dosage of 2.5mg/l Al at pH 6.4 yielded removal efficiencies of 62% for UV254, absorbing organic matter and the jar test showed almost the same removal (64%) for UV254 but with a significantly higher coagulant dosage. Finally, in the Mjörn case, the micro pilot method with a coagulant dosage of 3.5mg/l Al at a pH of 6.6 resulted in removal efficiencies of 76% for UV254, the jar test also resulted in 76% for UV254 at the same pH level.     While the micro pilot method showed better removal efficiencies, it consumed more chemicals compared to the jar test. The micro pilot experiments required higher volumes of coagulant and additional chemical backwashing after each set of experiments. In contrast, the jar test method used lesser quantities of coagulant and chemicals due to the smaller scale of the experiments.     The findings of this study highlight the superiority of the inline coagulation micro pilot method over the jar test for optimizing NOM removal in water treatment processes. Despite the jar test being quicker and more cost-effective, it often required higher coagulant dosages to achieve comparable results. This was mainly because jar test demands heavy and large enough flocs to be removed from the water. Conversely, the micro pilot method, although more time-consuming and costly, provided more precise coagulant dosage control, resulted in higher removal efficiencies, and offered a more comprehensive understanding of the coagulation process. This is achieved by using a sensor called EXO sensor, which allows for immediate monitoring of the treatment results.

No description available.

Submitted in fulfillment of the requirements for the degree of Master of Engineering in Chemical Engineering, Durban University of Technology. Durban. South Africa, 2015. / Several areas in the world such as the United States of America, Sri Lanka, China, Argentina, Canada, Tanzania, Kenya, South Africa and many others have a problem of high fluoride content in drinking water. Generally fluoride levels above 1.5 ppm in water may result in dental and skeletal fluorosis in humans depending on quantity consumed (Fan et al., 2003; Meenakshi, 2004). Remote rural areas where there are no water treatment facilities are more vulnerable to this problem. Adsorbents such as activated alumina and FR-10 resin seem to have a potential for successful application in rural areas. These methods however require pre-treatment if the feed has high turbidity. A membrane based system called woven fabric microfiltration gravity filter (WFMFGF) developed by Durban University of Technology proved to be suitable for turbidity removal. The main objective of this research was to develop a small water treatment system for fluoride removal. The small water treatment system developed in this study consists of WFMFGF for pre-treatment and an adsorption column. The WFMFGF is made up of a 40 L container packed with 15 immersed flat sheet membrane elements. The operation of the WFMFGF is in batch mode, driven by varying static head. The static head variation results in flow rate variation through the system. This in turn result in variation of contact time, velocity as well as pressure drop in the fluoride removal unit. Specific objectives of the study were: (1) to establish the maximum and minimum flow rates through the WFMFGF system, the total run time before cleaning is required and the best cleaning method for this particular membrane system. (2) to evaluate and compare the performance of activated alumina and FR-10 resin on varying contact time, velocity and pressure drop on the fluoride removal unit. The adsorbents were also compared on adsorption capacity, cost and ease of operation. The minimum and maximum flow rates through the WFMFGF were found to be 5 l/hr and 100 l/hr respectively. It was found that the system can be run for more than a month before requiring cleaning. The suitable cleaning method was found to be soaking the membranes in 0.0225 percent sodium hypochlorite solution overnight and brushing them using a plastic brush. The comparison of the performance of FR-10 resin to activated alumina found that the adsorbents gave equal performance based on the given criteria. FR-10 resin had higher adsorption capacity, gave good quality treated water even with shorter contact time and operated at wider velocity range. Activated alumina on the other hand had an advantage of lower costs, lower pressure drop and ease of use. According to Pontius (1990), the performance of activated alumina can be improved by intermittent operation. Point of use (POU) systems are generally operated intermittently. This improves the fluoride removal efficiency of activated alumina giving it more advantage over FR-10 resin. Based on this activated alumina was selected as the best adsorbent for the system. After the adsorbent was selected, the adsorption column was designed. The column operation regime was 3.5 minutes minimum contact time and 1.17 to 7.8 m/hr velocity range. The activated alumina adsorption capacity was 1.53mg/g. The column had an inside diameter of 70 mm. It was packed with activated alumina to a bed height of 400 mm. The column inlet and outlet pipes were made of PVC with a standard pipe size of 20 mm outside diameter. A valve at the column inlet pipe allowed water to flow through the system.

O presente trabalho avaliou o desempenho de filtros de areia biológicos no tratamento da água do mar a fim de controlar a formação de biofilmes microbianos em membranas de osmose reversa, utilizadas para o processo de dessalinização, e posteriormente em tanques de cultivo de peixes. Para isto, proteínas e carboidratos (principais componentes de biofilmes) foram quantificados em corpos de prova expostos à diferentes tratamentos. A água produzida pelos tratamentos também foi avaliada por meio da quantificação de microrganismos e teor de carbono orgânico assimilável (AOC), que está associado ao potencial de crescimento microbiano (PCM). A capacidade dos filtros em reduzir turbidez e SDI a partir da água captada no mar, também constituiu um parâmetro de avaliação. A partir dos dados obtidos foi possível verificar que os sistemas de tratamento da água do mar constituídos por filtros lentos de areia são capazes de reduzir a incidência de biofilmes em membranas de osmose reversa (reduzindo em até cerca de 80% a concentração de proteínas e 88% a de carboidratos). Porém, para que se tenha uma taxa significativa de remoção do AOC e redução do PCM, esses sistemas requerem um tempo de maturação entre 50 e 60 dias. Por outro lado, em termos de redução de turbidez e SDI, esses sistemas demonstram eficiência praticamente imediata, resultando em uma água com turbidez sempre menor que 0.3 UNT e SDI sempre menor que 4. Como forma de tratamento de água do mar para sistemas de aquicultura, os filtros lentos de areia demonstraram capacidade em reduzir a formação de biofilmes e a deposição de material particulado dentro dos tanques de cultivo, sendo esta redução mais evidente no fundo dos tanques e na observação realizada após 31 dias. O uso de filtros de areia para o tratamento da água utilizada no cultivo de peixes pode contribuir para redução da frequência de manejo e limpeza de tanques. / The present work has evaluated the performance of biological sand filters in seawater treatment in order to control microbial biofilms formation in reverse osmosis membranes used for the desalination process. The same filters were also evaluated as a seawater treatment system for aquaculture, and the performance in biofilms control inside the fish tanks was verified. To evaluate the performance in terms of biofilms control, proteins and carbohydrates (main components of biofilms) were quantified in specimens exposed to different treatments. The water produced by the treatments was also evaluated by microorganisms concentration and assimilable organic carbon content, which is associated with microbial growth potential. The performance of turbidity removal and SDI reduction from raw water was also an evaluation parameter. From the data obtained, it was observed that seawater treatment systems by of slow sand filters are able to reduce reverse osmosis membranes biofilms (up to 80% proteins concentration and 88% carbohydrate concentration). However, in order to have a significant rate of AOC removal and PCM reduction, these systems need a maturation time between 50 and 60 days. On the other hand, in terms of turbidity removal and SDI reduction, these systems demonstrate immediate efficiency, resulting in water turbidity always less than 0.3 NTU and SDI always less than 4. The slow sand filters showed efficience to reduce the biofilm formation and material deposition inside the fish tanks, this reduction was more evident at the bottom of the tanks and after 31 days. The use of sand filters as a water treatment for fish farming can contribute to reduce the number of procedures for handling and cleaning tanks.

Thesis (MScEng)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: The purpose of this study was to develop modi ed tract-etched membranes using nanocomposite TiO2 for advanced water treatment processes. Photocatalytic oxidation and reduction reactions take place on TiO2 surfaces under UV light irradiation, therefore sunlight and even normal indoor lighting could be utilised to achieve this effect. In membrane ltration, caking is a major problem, by enhancing the anti-fouling properties of photocatalysts to mineralise organic compounds the membrane life and e ciency can be improved upon. In this study the rst approach in nanocomposite membrane development was to directly modify the surface of polyethylenetherephthalate (PET) track-etched membranes (TMs) with titanium dioxide (TiO2) using inverted cylindrical magnetron sputtering (ICMS) for TiO2 thin lm deposition. The second approach was rst to thermally evaporate silver (Ag) over the entire TM surface, followed by sputtering TiO2 over the silver-coated TM. As a result a noble metal-titania nanocomposite thin lm layer is produced on top of the TM surface with both self-cleaning and superhydrophilic properties. Reactive inverted cylindrical magnetron sputtering is a physical vapour deposition method, where material is separated from a target using high energy ions and then re-assimilated on a substrate to grow thin lms. Argon gas is introduced simultaneously into the deposition chamber along with O2 (the reactive gas) to form TiO2. The photocatalytic activity and other lm properties, such as crystallinity can be in uenced by changing the sputtering power, chamber pressure, target-to-substrate distance, substrate temperature, sputtering gas composition and ow rate. These characteristics make sputtering the perfect tool for the preparation of di erent kinds of TiO2 lms and nanostructures for photocatalysis. In this work, the utilisation of ICMS to prepare photocatalytic TiO2 thin lms deposited on track-etched membranes was studied in detail with emphasis on bandgap reduction and TM surface regeneration. Nanostructured TiO2 photocatalysts were prepared through template directed deposition on track-etched membrane substrates by exploiting the good qualities of ICMS. The TiO2-TM as well as Ag-TiO2-TM thin lms were thoroughly characterised. ICMS prepared TiO2 lms were shown to exhibit good photocatalytic activities. However, the nanocomposite Ag-TiO2 thin lms were identi ed to be a much better choice than TiO2 thin lms on their own. Finally a clear enhancement in the photocatalytic activity was achieved by forming the Ag-TiO2 nanocomposite TMs. This was evident from the band-gap improvement from 3.05 eV of the TiO2 thin lms to the 2.76 eV of the Ag-TiO2 thin lms as well as the superior surface regenerative properties of the Ag-TiO2-TMs. / AFRIKAANSE OPSOMMING: Die doel van hierdie studie was om verbeterde baan-ge etste membrane (BMe) met behulp van nano-saamgestelde titaandioksied (TiO2) vir gevorderde water behandeling prosesse te ontwikkel. Fotokatalitiese oksidasie- en reduksie reaksies vind plaas op die TiO2 oppervlaktes onder UV-lig bestraling, en dus kan sonlig en selfs gewone binnenshuise beligting gebruik word om die gewenste uitwerking te verkry. In membraan ltrasie is die aanpaksel van onsuiwerhede 'n groot probleem, maar die verbetering van die self-reinigende eienskappe van fotokatalisators deur organiese verbindings te mineraliseer, kan die membraan se leeftyd en doeltre endheid verbeter word. In hierdie studie was die eerste benadering om nano-saamgestelde membraan ontwikkeling direk te verander deur die oppervlak van polyethylenetherephthalate (PET) BMe met 'n dun lagie TiO2 te bedek, met behulp van reaktiewe omgekeerde silindriese magnetron verstuiwing (OSMV).Die tweede benadering was eers om silwer (Ag) termies te verdamp oor die hele BM oppervlak, gevolg deur TiO2 verstuiwing bo-oor die silwer bedekte BM. As gevolg hiervan is 'n edelmetaal-titanium nano-saamgestelde dun lm laag gevorm bo-op die oppervlak van die BM, met beide self-reinigende en verhoogde hidro liese eienskappe. OSMV is 'n siese damp neerslag metode, waar materiaal van 'n teiken, met behulp van ho e-energie-ione, geskei word, en dan weer opgeneem word op 'n substraat om dun lms te vorm. Argon gas word gelyktydig in die neerslag kamer, saam met O2 (die reaktiewe gas), vrygestel om TiO2 te vorm. Die fotokatalitiese aktiwiteit en ander lm eienskappe, soos kristalliniteit, kan be nvloed word deur die verandering van byvoorbeeld die verstuiwingskrag, die druk in die reaksiekamer, teiken-tot-substraat afstand, substraattemperatuur, verstuiwing gassamestelling en vloeitempo. Hierdie eienskappe maak verstuiwing die ideale hulpmiddel vir die voorbereiding van die verskillende soorte TiO2 lms en nanostrukture vir fotokatalisasie. In hierdie tesis word OSMV gebruik ter voorbereiding van fotokatalitiese TiO2 dun lms, wat gedeponeer is op BMe. Hierdie lms word dan in diepte bestudeer, met die klem op bandgaping vermindering en BM oppervlak hergenerasie. Nanogestruktureerde TiO2 fotokataliste is voorberei deur middel van sjabloongerigte neerslag op BM substrate deur die ontginning van die goeie eienskappe van OSMV. Die TiO2-BM dun lms, sowel as Ag-TiO2-BM dun lms, is deeglik gekarakteriseer. OSMV voorbereide TiO2 dun lms toon goeie fotokatalitiese aktiwiteite. Nano-saamgestelde Ag-TiO2 dun lms is egter ge denti seer as 'n veel beter keuse as TiO2 dun lms. Ten slotte is 'n duidelike verbetering in die fotokatalitiese aktiwiteit bereik deur die vorming van die Ag-TiO2 nano-saamgestelde BMe. Dit was duidelik uit die bandgapingverbetering van 3,05 eV van TiO2 dun lms in vergelyking met die 2,76 eV van Ag-TiO2 dun lms. 'n Duidelike verbetering is behaal in die fotokatalitiese aktiwiteit deur die vorming van die Ag-TiO2 nano-saamgestelde TMs.

Ce travail de thèse concerne l'étude et l'évaluation de l'extraction et de la séparation de molécules d'intérêt à partir des résidus de colza. L'impact des différents traitements (broyage, champs électriques pulsés, décharges électriques de hautes tensions et ultrasons) sur l'amélioration de l'extraction des polyphénols et des protéines à partir des tiges de colza a été comparé. Ces traitements permettent d'endommager les membranes et/ou parois cellulaires de manière mécanique, électrique ou acoustique, facilitant ainsi la libération des composés intracellulaires vers le milieu extérieur. La cinétique d'extraction, le rendement en polyphenols totaux et en protéines et la consommation énergétique sont principalement étudiés. De plus, l'efficacité des traitements étudiés pour l'extraction des polyphénols et protéines, en fonction du degré de maturité de la plante a été étudiée. Les méthodes testées pour la séparation des extractibles (polyphénols et protéines) concernent la coagulation, la filtration membranaire ainsi que le couplage de ces deux méthodes afin de réduire la consommation de solvants organiques et la rétention des polyphénols au cours de séparation. La séparation des extractibles a été évaluée par le biais de l'analyse de pureté et du taux de rétention. Enfin, des effets positifs du traitement électrique sur l'étape de séparation des extractibles tels que l'augmentation du flux du perméat et la diminution du colmatage ont été remarqués. / This thesis work concerns the study and the evaluation of the extraction and the separation of valuable compounds from rapeseed residues. The impact of different treatments (grinding, pulsed electric fields, high voltage electrical discharges and ultrasound) on the enhancement of the extraction of polyphenols and proteins from rapeseed stems was compared. These treatments can damage cell membranes and 1 or cell walls mechanically, electrically or acoustically, thus facilitating the release of intracellular compounds to the surroundings. The extraction kinetics, yield of total polyphenols and proteins and energy consumption were mainly studied. In addition, influences of plant maturity on the efficiency of studied treatments for the extraction of polyphenols and proteins have been studied. The methods tested for the separation of extractives (polyphenols and proteins) include coagulation, membrane filtration and the combination of these two methods in order to reduce the consumption of organic solvents and the retention ofpolyphenols during separation. The separation of extractives was evaluated by means of analysis of purity and relative removal. Finally, positive effects of electrical treatment on the extractive separation step such as the increase ofpermeate flux and the decrease of membrane fouling have been observed.

This diploma thesis explores treatment options of wastewater with a low presence of organic pollution produced by minor pollution sources. The research part describes objects with a low presence of organic pollution in wastewater and possible treatment methods in dependence of pollution source's size. The practical part contains the design of technological options of treatment of wastewater with a low presence of organic pollution for a specific object.

Climate change and increasing population demands expansion of infrastructures in urban areas. Drinking water treatment plants are part of the critical infrastructure and must upgrade in the future. However, expansions and technological advancements often come with impacts on the environment. Therefore, this thesis compares two drinking water treatment technologies regarding its environmental impacts through a life cycle assessment. In specific, the thesis elaborates the impacts of membrane precipitation and conventional precipitation in the suspended solids removal stage at a treatment plant in Piteå, Sweden. The research addresses the environmental challenges posed by traditional and modern water treatment methods, providing insights and knowledge to more sustainable water practices. The research involves an attributional, comparative life cycle assessment. The findings from this thesis intend to guide decision-making for future drinking water treatment plant designs.  The research was conducted through an attributional and comparative LCA using SimaPro software based on ISO 14040-series standards. This approach allowed for a detailed analysis of both the operational and construction phases of the treatment technologies, considering various environmental impact categories.  The results indicate that membrane system presents for most impact categories, a lower  environmental impact in the combined configuration scenario. The combined configuration scenario includes for the membrane system calcium carbonate, aluminium sulfate and 95% reduced hypochlorite consumption. The conventional system considers in the combined configuration scenario aluminum sulfate and calcium carbonate This is primarily due to its efficiency in reducing chemical usage such as coagulants. However, if both systems use the same chemical composition (same coagulant, pH-controlling chemicals as in the base scenario), the conventional system becomes more environmentally friendly than the membrane system in most impact categories. This is mainly due to the additional CEB chemical consumption of the membrane system, which nullifies the advantage of lower consumed coagulants. Compared to the operational phase in both systems, the construction phase is insignificant over the lifetime of the treatment plants. The major hotspots are identified as operational chemicals and chemical enhanced backwash chemicals, which are used for the membrane system only. Scenario analysis shows that chlorine/aluminum-based chemicals such as polyaluminum chloride and hypochlorite have a high environmental impact and with reducing or even changing these chemicals major improvements can be achieved. Especially changing aluminum-based chemicals to iron-based chemicals show a significant decrease of impacts in all categories. Further, the scenario analysis shows that by changing lime to calcium carbonate, the environmental impacts can be reduced significantly. Therefore, the future focus should rely on reducing and changing chemicals, especially switching aluminum/chlorine based to iron-based chemicals. / Klimatförändringarna och den ökande befolkningen kräver utbyggnad av infrastrukturen i stadsområden. Reningsverk för dricksvatten är en del av den kritiska infrastrukturen och måste uppgraderas i framtiden. Expansioner och tekniska framsteg medför dock ofta påverkan på miljön. Detta examensarbete jämförs därför två tekniker för dricksvattenberedning med avseende på miljöpåverkan genom en grundlig livscykelanalys. Mer specifikt behandlar avhandlingen effekterna av membranfiltrering och konventionell fällning i steget för avlägsnande av suspenderade ämnen vid ett reningsverk i Piteå, Sverige. Forskningen tar upp de miljömässiga utmaningar som traditionella och moderna vattenbehandlingsmetoder innebär och ger insikter och kunskap om mer hållbara vattenmetoder. Resultaten från denna avhandling är avsedda att vägleda beslutsfattandet för framtida utformningar av dricksvattenreningsverk och erbjuder ett första verktyg för mer hållbara vattenbehandlingsmetoder.  Forskningen genomfördes genom en bokförande och jämförande LCA med hjälp av programvaran SimaPro baserat på ISO 14040-seriens standarder. Detta tillvägagångssätt möjliggjorde en detaljerad analys av både drifts- och konstruktionsfaserna för behandlingsteknikerna, med beaktande av olika miljöpåverkanskategorier.  Resultaten tydar på att membranfiltrering ger en lägre total miljöpåverkan vid vanliga förhållanden. Detta beror främst på dess effektivitet när det gäller att minska kemikalieanvändningen, t.ex. koaguleringsmedel. Men om båda systemen använder samma kemiska sammansättning (samma koaguleringsmedel) är det konventionella systemet mer miljövänligt än det konventionella systemet. Detta beror främst på den extra kemikalieförbrukningen för CEB i membransystemet, vilket upphäver fördelen med lägre förbrukning av koaguleringsmedel. Jämfört med driftsfasen i båda systemen är byggfasen obetydlig under reningsverkens livstid. De viktigaste aspekterna identifieras som driftskemikalier och kemikalier för kemiskt förstärkt backspolning, som endast används för membransystemet. Scenarioanalysen visar att klor-/aluminiumbaserade kemikalier som polyaluminiumklorid och hypoklorit har en hög miljöpåverkan och att stora förbättringar kan uppnås genom att minska eller till och med byta ut dessa kemikalier. Särskilt om aluminiumbaserade kemikalier byts ut mot järnbaserade kemikalier minskar påverkan betydligt i alla kategorier. Vidare visar scenarioanalysen att miljöpåverkan kan minskas betydligt genom att byta ut kalk mot kalciumkarbonat. Därför bör fokus i framtiden ligga på att minska och byta ut kemikalier, särskilt att byta ut aluminium/klorbaserade kemikalier mot järnbaserade kemikalier.

[ES] La problemática de los metales pesados en cuerpos de agua superficial se ha observado a nivel mundial y ha sido objeto de múltiples estudios. La presencia de metales en concentraciones por encima de los límites establecidos adquiere mayor relevancia cuando estos se encuentran en fuentes de agua para abastecimiento público. Esta investigación toma como área de estudio a la Microcuenca Milluni, la cual se encuentra cercana de actividades mineras pasadas e ilegales que afectan directamente sobre sus recursos hídricos. Milluni está ubicada en el departamento de La Paz y es una fuente natural de agua para dos ciudades importantes de Bolivia, La Paz y El Alto (540 000 habitantes aproximadamente). El objetivo de esta tesis doctoral es estudiar la implementación de la Ósmosis Inversa (OI) operada a bajas presiones como alternativa sostenible de tratamiento para eliminar la contaminación minera en las aguas de Milluni. Adicionalmente se busca contribuir a la gestión de recursos hídricos, con énfasis en el control de la de calidad de agua en la zona. Esta investigación doctoral se desarrolló en cuatro etapas. En la primera etapa se hizo la caracterización de los cuerpos de agua superficiales para identificar el metal pesado más peligroso presente en Milluni. Para ello, se diseñó un programa de monitoreo considerando las particulares características y limitaciones en la gestión del agua del área. En la segunda etapa del estudio se formularon dos mecanismos para fortalecer la gestión del agua de Milluni, planteando complementar el programa de monitoreo tradicional con la herramienta de teledetección de contaminantes e identificar las partes interesadas de Milluni, para contribuir a la toma de decisiones de la zona. En la tercera etapa de la investigación se diseñó, montó y puso en marcha una planta piloto de OI, tecnología seleccionada debido a su alta eficiencia en la separación de compuestos iónicos del agua. Además, se realizó un diseño de experimentos para estudiar el comportamiento y eficiencia de una membrana tipo ULP 2540 Marca Keensen. Finalmente, en la cuarta etapa se desarrolló un análisis estadístico de los resultados experimentales obtenidos, y la validación de los mismos por medio de un modelo matemático basado en el modelo de concentración de polarización de Spiegler-Kedem. El modelo incluyo un factor de ajuste de temperatura tipo Arrhenius, para obtener una predicción precisa del rendimiento del proceso. Esta tesis doctoral concluye que es posible remover el arsénico presente en aguas sintéticas utilizando la OI operada en condiciones sostenibles de presión (presiones bajas). Se ha demostrado que el uso de esta tecnología a baja presión no afecta a la eficiencia de separación del proceso y contribuye a disminuir el costo energético durante la operación. Este aporte es significativo en situaciones donde se cuenta con pocos recursos económicos y existen riesgos inminentes sobre la salud pública y los ecosistemas, como es el caso de la contaminación del agua por arsénico en Milluni, Bolivia. / [CA] La problemàtica dels metals pesats en cossos d'aigua superficial s'ha observat a nivell mundial i ha segut objecte de múltiples estudis. La presència de metals en concentracions per damunt dels llímits establits adquirix major rellevància quan estos es troben en fonts d'aigua per a abastiment públic. Esta investigació pren com a àrea d'estudi a la Microcuenca Milluni, la qual es troba propenca d'activitats mineres passades i illegals que afecten directament sobre els seus recursos hídrics. Milluni està ubicada en el departament de la Pau i és una font natural d'aigua per a dos ciutats importants de Bolívia, La Pau i L'Alt (540 000 habitants aproximadament). L'objectiu d'esta tesis doctoral és estudiar l'implementació de la Òsmosis Inversa (OI) operada a baixes pressions com a alternativa sostenible de tractament per a eliminar la contaminació minera en les aigües de Milluni. Adicionalment es busca contribuir a la gestió de recursos hídrics, en émfasis en el control de la de calitat d'aigua en la zona. Esta investigació doctoral es va desenrollar en quatre etapes. En la primera etapa es va fer la caracterisació dels cossos d'aigua superficials per a identificar el metal pesat més perillós present en Milluni. Per a això, es va dissenyar un programa de monitoreo considerant les particulars característiques i llimitacions en la gestió de l'aigua de l'àrea. En la segona etapa de l'estudi es varen formular dos mecanismes per a enfortir la gestió de l'aigua de *Milluni, plantejant complementar el programa de monitoreo tradicional en la ferramenta d' teledetección de contaminants i identificar les parts interessades de Milluni, per a contribuir a la presa de decisions de la zona. En la tercera etapa de l'investigació es va dissenyar, va montar i va posar en marcha una planta pilot de OI, tecnologia seleccionada per la seua alta eficiència en la separació de composts iònics de l'aigua. Ademés, es va realisar un disseny d'experiments per a estudiar el comportament i eficiència d'una membrana tipo ULP 2540 Marca Keensen. Finalment, en la quarta etapa es va desenrollar un anàlisis estadístic dels resultats experimentals obtinguts, i la validació dels mateixos per mig d'un model matemàtic basat en el model de concentració de polarisació de Spiegler-Kedem. El model incloc un factor d'ajust de temperatura tipo Arrhenius, per a obtindre una predicció precisa del rendiment del procés. Esta tesis doctoral conclou que és possible remoure l'arsènic present en aigües sintètiques utilisant la OI operada en condicions sostenibles de pressió (pressions baixes). S'ha demostrat que l'us d'esta tecnologia a baixa pressió no afecta a l'eficiència de separació del procés i contribuïx a disminuir el cost energètic durant l'operació. Este aporte és significatiu en situacions a on es conta en pocs recursos econòmics i existixen riscs imminents sobre la salut pública i els ecosistemes, com és el cas de la contaminació de l'aigua per arsènic en Milluni, Bolívia. / [EN] The problem of heavy metals in surface water bodies has been observed worldwide and has been the subject of multiple studies. The presence of metals in concentrations above the established limits becomes more relevant when they are found in water sources for public supply. This research takes the Milluni Micro-basin as a study area, which is close to past and illegal mining activities that directly affect its water resources. Milluni is located in the department of La Paz and is a natural source of water for two important cities in Bolivia, La Paz and El Alto (approximately 540,000 inhabitants). This doctoral thesis aims to study the implementation of Reverse Osmosis (RO) operated at low pressures as a sustainable treatment alternative to eliminate mining contamination in Milluni waters. Additionally, it seeks to contribute to the management of water resources, with an emphasis on the control of water quality in the area. This doctoral research was developed in four stages. In the first stage, surface water bodies were characterized to identify the most dangerous heavy metal present in Milluni. For this, a monitoring program was started considering the particular characteristics and limitations of water management in the area. In the second stage, two mechanisms were formulated to strengthen Milluni's water management, proposing to complement the traditional monitoring study program with the contaminant remote sensing tool and to identify the invited parties of Milluni to contribute to the decision-making of the area. In the third stage of the investigation, a RO pilot plant was worked on, assembled, and started up, a technology selected due to its high efficiency in separating ionic compounds from water. In addition, a design of experiments was carried out to study the behavior and efficiency of a ULP 2540 Keensen brand membrane. Finally, in the fourth stage, a statistical analysis of the experimental results obtained was presented, and their validation using a mathematical model based on the Spiegler-Kedem polarization concentration model. The model includes an Arrhenius-type temperature adjustment factor to accurately predict the process performance. This doctoral thesis concludes that it is possible to remove the arsenic present in synthetic waters using the RO operated under sustainable pressure conditions (low pressures). It has been shown that the use of this technology at low pressure does not affect the separation efficiency of the process and contributes to lower energy costs during operation. This contribution is significant in situations with few economic resources and imminent risks to public health and ecosystems, as is the case of water contamination by arsenic in Milluni, Bolivia. / Alvizuri Tintaya, PA. (2022). Estudio de la ósmosis inversa operada a baja presión como tratamiento de una fuente natural contaminada por actividad minera, en la micro cuenca Milluni en Bolivia, para el abastecimiento de agua segura a poblaciones [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/191428