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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

Development of Low-Biofouling Polypropylene Feed Spacers for Reverse Osmosis

Hausman, Richard January 2011 (has links)
No description available.
82

Removal of bacteria by reverse osmosis method.

Anyahuru, Emmanuel Achonna January 1972 (has links)
No description available.
83

Optimal design and operation of reverse osmosis desalination process with membrane fouling

Sassi, Kamal M., Mujtaba, Iqbal M. January 2011 (has links)
No description available.
84

Scope and limitations of the irreversible thermodynamics and the solution diffusion models for the separation of binary and multi-component systems in reverse osmosis process

Al-Obaidi, Mudhar A.A.R., Kara-Zaitri, Chakib, Mujtaba, Iqbal M. 05 February 2017 (has links)
Yes / Reverse osmosis process is used in many industrial applications ranging from solute-solvent to solvent-solvent and gaseous separation. A number of theoretical models have been developed to describe the separation and fluxes of solvent and solute in such processes. This paper looks into the scope and limitations of two main models (the irreversible thermodynamics and the solution diffusion models) used in the past by several researchers for solute-solvent feed separation. Despite the investigation of other complex models, the simple concepts of these models accelerate the feasibility of the implementation of reverse osmosis for different types of systems and variety of industries. Briefly, an extensive review of these mathematical models is conducted by collecting more than 70 examples from literature in this study. In addition, this review has covered the improvement of such models to make them compatible with multi-component systems with consideration of concentration polarization and solvent-solute-membrane interaction.
85

Significant energy savings by optimising membrane design in multi-stage reverse osmosis wastewater treatment process

Al-Obaidi, Mudhar A.A.R., Kara-Zaitri, Chakib, Mujtaba, Iqbal M. 18 January 2018 (has links)
Yes / The total energy consumption of many Reverse Osmosis (RO) plants has continuously improved as a result of manufacturing highly impermeable membranes in addition to implementing energy recovery devices. The total energy consumption of the RO process contributes significantly to the total cost of water treatment. Therefore any way of keeping the energy consumption to a minimum is highly desirable but continues to be a real challenge in practice. Potential areas to explore for achieving this include the possibility of optimising the module design parameters and/or the associated operating parameters. This research focuses on this precise aim by evaluating the impact of the design characteristics of membrane length, width, and feed channel height on the total energy consumption for two selected pilot-plant RO process configurations for the removal of chlorophenol from wastewater. The proposed two configurations, with and without an energy recovery device (ERD), consist of four cylindrical pressure vessels connected in series and stuffed with spiral wound membranes. A detailed steady-state model developed earlier by the authors is used here to study such impact via repetitive simulation. The results achieved confirm that the overall energy consumption can be reduced by actually increasing the membrane width with a simultaneous reduction of membrane length at constant membrane area and module volume. Energy savings of more than 60% and 54% have been achieved for the two configurations with and without ERD respectively using process optimization. The energy savings are significantly higher compared to other available similar studies from the literature.
86

Performance evaluation of reverse osmosis brackish water desalination plant with different recycled ratios of retentate

Alsarayreh, Alanood A., Al-Obaidi, Mudhar A.A.R., Al-Hroub, A.M., Patel, Rajnikant, Mujtaba, Iqbal M. 28 March 2022 (has links)
Yes / Reverse Osmosis (RO) process has become one of the most widely utilised technologies for brackish water desalination for its capabilities of producing high-quality water. This paper emphasis on investigating the feasibility of implementing the retentate recycle design on the original design of an industrial medium-sized multistage and multi-pass spiral wound brackish water RO desalination plant (1200 m³/day) of Arab Potash Company (APC) located in Jordan. Specifically, this research explores the impact of recycling the high salinity stream of the 1st pass (at different recycled percentages) to the feed stream on the process performance indicators include, the fresh water salinity, overall recovery rate, and specific energy consumption. The simulation is carried out using an earlier model developed by the same authors for the specified RO plant using gPROMS suits. This confirmed the possibility of increasing the product capacity by around 3% with 100% recycle percentage of the high salinity retentate stream.
87

Flexible design and operation of multi-stage reverse osmosis desalination process for producing different grades of water with maintenance and cleaning opportunity

Al-Obaidi, Mudhar A.A.R., Rasn, K.H., Aladhwani, S.H., Kadhom, M., Mujtaba, Iqbal M. 20 April 2022 (has links)
Yes / The use of Reverse Osmosis (RO) process in seawater desalination to provide high-quality drinking water is progressively increased compared to thermal technologies. In this paper, multistage spiral wound RO desalination process is considered. Each stage consists of several pressure vessels (PVs) organised in parallel with membrane modules in each PV being organised in series. This allows disconnecting a set of PVs and membrane modules depending on the requirement of cleaning and maintenance. While this flexibility offers the opportunity of generating several RO configurations, we presented only four such configurations of the RO system and analysed them via simulation and optimisation. Production of different grades of water catering different needs of a city is also considered for each of these configurations. The optimisation has resulted in the optimal operating conditions, which maximises the water productivity and minimises the specific energy consumption of the proposed configurations for a given water grade in terms of salinity. For instance, the results indicate that the proposed RO networks can produce drinking water of 500 ppm salinity with a minimum specific energy consumption of 3.755 kWh/m3. The strategy offers the production of different grades of water without plant shutdown while maintaining the membrane modules throughout the year.
88

Synthesis and Characterization of Hydrophobic-Hydrophilic  Multiblock Copolymers for Proton Exchange Membrane and Segmented Copolymer Precursors for Reverse Osmosis Applications

Mehta, Ishan 03 July 2014 (has links)
High performance engineering materials, poly(arylene ether)s, having very good mechanical properties, excellent oxidative and hydrolytic stability are promising candidates for alternative materials used in the field of Proton Exchange Membrane Fuel Cells (PEMFCs) and Reverse Osmosis (RO) applications. In particular, wholly aromatic sulfonated poly(arylene ether sulfone)s are of considerable interest in the field of PEMFCs and RO, due to their affordability, high Tg, and the ease of sulfonation. Proton exchange membrane fuels cells (PEMFCs) are one of the primary alternate source of energy. A Proton exchange membrane (PEM) is one of the key component in a PEMFC and it needs to have good proton conductivity under partially humidified conditions. One of the strategies to increase proton conductivity under partially RH conditions is to synthesize hydrophobic-hydrophilic multiblock copolymers with high Ion exchange capacity (IEC) values to ensure sufficient ion channel size. In this thesis two multiblock systems were synthesized incorporating trisulfonated hydrophilic oligomers and were characterized in the first two chapters of the thesis. The first multiblock system incorporated a non-fluorinated biphenol-based hydrophobic block. The second study was focused on synthesizing a fluorinated benzonitrile-based hydrophobic block. A fluorinated monomer was incorporated with the aim to improve phase separation which might lead to increased performance under partially humidified conditions. The third study featured synthesis and characterization of a novel hydroquinone-based random copolymer system precursor, which after post-sulfonation, shall form mono-sulfonated polysulfone materials with potential applications in reverse osmosis. The ratio of the amount of hydroquinone incorporated in the copolymer were varied during the synthesis of the precursor to facilitate control over the post-sulfonation process. The simple and low cost process of post-sulfonating the random copolymer enables the precursor to be a promising material to be used in the reverse osmosis application. / Master of Science
89

Removal of organic contaminants from groundwater by reverse osmosis

Robinson, Michael A. 14 March 2009 (has links)
The performance of a poly(ether/urea) membrane has been evaluated in a full scale reverse osmosis system. A series of experiments were conducted with six aromatic compounds - anthracene, pyrene, fluorene, 2-chlorobiphenyl, 2,4,6 trichlorophenol, and pentachlorophenol- and four volatile compounds - trichloromethane, bromodichloromethane, dibromochloromethane, and trichloroethene - as single and multi-solute contaminants. The objectives of the experiments were to determine if poly(ether/urea) membranes could produce a permeate that met maximum contaminant levels (MCL) set by the Safe Drinking Water Act (SDWA) and to correlate membrane performance with physical/chemical properties of the solute contaminants. Aromatic contaminants were removed to concentrations below the current MCLs. However, volatile contaminants were not sufficiently rejected by the membrane to meet either the MCL for total trihalomethanes or trichloroethene. Sorption onto the poly(ether/urea) was found to occur for several of the aromatic compounds tested in this research. This prevented developing any relationship between membrane performance and physical/chemical properties of the solute. / Master of Science
90

Avsaltningsanläggning för dricksvatten : En undersökning av förutsättningarna att säkra färskvattentillgången i Mönsterås kommun / Desalination plant for drinking water

Larsson, Olof January 2023 (has links)
Detta arbete utreder möjligheten att säkra vattentillgången i Mönsterås kommun med hjälp av en avsaltningsanläggning för bräckvatten från östersjön. Det är högst troligt ett sådant vattenverk skulle kunna uppföras i kommunen och dessutom ge ett vatten med lägre halter av oönskade ämnen än vatten renat med konventionella metoder från yt- och grundvatten till en marginellt högre kostnad. I arbetet redovisas kortfattat principen för avsaltning med RO (Reverse osmosis).  Uppbyggnaden av två vattenverk som använder den tekniken och likt Mönsterås ligger i Kalmarsund beskrivs. Med information från sjökort och kartor har troliga råvattentillgångar i kommunen identifierats och utifrån dessa grundar sig förslagen för placering. Med hjälp från ett flertal kontakter i branschen har en enklare projektering gjorts för ett vattenverk med kapacitet på 3000 kubikmeter dricksvatten per dygn. I resultatet redovisas några förslag på placering av ett vattenverk. / This work investigates the possibility of securing the water supply in Mönsterås municipality with the help of a desalination plant for brackish water from the Baltic Sea. It is highly likely that such a waterworks could be built in the municipality and also provide water with lower levels of unwanted substances than water purified by conventional methods from surface and groundwater at a marginally higher cost. In the work, the principle of desalination with RO (Reverse osmosis) is briefly presented.  The construction of two waterworks that use this technology and, like Mönsterås, is located in Kalmarsund is described.  With information from nautical charts and maps, probable raw water resources in the municipality have been identified and based on these, the proposals for placement are based. With the help of several contacts in the industry, a simpler design has been made for a water treatment plant with a capacity of 3000 cubic meters of drinking water per day. The result presents some suggestions for placement of a desalination plant.

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