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1
Gilabert, Oriol Guillem. "Optimization of ultrafiltration membrane cleaning processes. Pretreatment for reverse osmosis in seawater desalination plants." Doctoral thesis, Universitat Rovira i Virgili, 2013. http://hdl.handle.net/10803/108954.
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Esta tesis explica com mejorar la eficiencia del proceso de ultrafiltración en la desalinización de agua de mar. Esto se consigue optimizando diferentes procesos de limpieza como los contralavados y las limpiezas químicas mejoradas. Para conseguirlo se siguen diferentes estrategias como reducir el número de pasos de los contralavados, reducir la frecuencia de los contralavados, usar salmorra proveniente del concentrado de osmosis y reducir el consumo de químicos. Se propone una nueva metodología para analizar los ciclos de limpieza mediante la modelización del proceso. Diferentes tipos de fibra son analizados mediante su permeabilidad y tolerancia a la suciedad. Se presenta una nueva metodología para prevenir la cloración de las membranas de osmosis inversa causadas por las limpiezas químicas mejoradas que se llevan a cabo aguas arriba. Todos los descubrimientos son validados con datos obtenidos de plantas reales. Estas mejoras aumentan la eficiencia del proceso hasta al 98% y reducen el coste de operación de la ultrafiltración en un 7%.<br>This thesis gives an overview on how to improve efficiency of the ultrafiltration filtration process in seawater desalination. This is achieved by optimizing different cleaning processes such as the backwash and the chemical enhanced backwash. Key success factors rely on reducing the number of backwash steps, improving the backwash frequency, using reverse osmosis brine for backwashing and reducing the chemical consumption. A new methodology to analyze these cleanings cycles is proposed through modeling the process. Different fibers types are also analyzed according to its permeability and its fouling tolerance. A methodology to prevent reverse osmosis chlorination from upstream chemical enhanced backwash cleaning is presented. All the findings are validated through real plant operating data. The proposed improvements increase the process efficiency to 98% and lead to a 7% cost reduction in the ultrafiltration process.
2
Lindkvist, Jonas. "Social, Economical and Technical Evaluation of a reverse osmosis drinking water plant in the Stockholm Archipelago." Thesis, KTH, Industriell ekologi, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-32777.
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The drinking water plant in this case study is a combined groundwater and reverse osmosisplant in the Stockholm archipelago. The reverse osmosis purification step was added to theplant in 1995. This technique is relatively new in Sweden and there are possibilities for it tobecome a good complement to conventional drinking water treatment. The plant has used thistechnique for over 10 years with good results. It is therefore of great interest to evaluate anddocument it for the possibility to implement this technique in areas not connected toconventional drinking water production.Reverse osmosis separates the incoming water to a clean permeate and concentrate ofremoved particles, larger molecules and ions. This technique has a high purification degree. Itcan remove dissolved particles and microorganisms without disinfection. However, it isrelatively expensive due to a high electricity consumption compared to conventional drinkingwater treatment. The high electricity consumption in this kind of system depends on aphenomenon called membrane fouling caused by the constituents in the raw water, graduallybecoming enriched on the membrane surface.The aim of this thesis was to evaluate and document a drinking water plant in the Stockholmarchipelago from a social, economical, technical and environmental perspective. A socialsurvey in the form of a questionnaire was conducted to reveal opinions about the water qualityprovided by the plant. The economical evaluation was done to estimate the cost of drinkingwater production and find the water cost in Kr/m3. The technical part involved documentationof the plant layout and evaluation of its performance. To assess the performance historicalchemical and microbial analyses were evaluated. A mass balance was attempted to drawconclusions for the overall system. The environmental part of the plant assessment, includedan estimate of the electricity and chemicals use in the plant.The results revealed that from an overall perspective the water quality from the plant issatisfactory with some concerns about metal taste and turbidity that sometimes occur. Thepotential presence of dangerous algal toxins in the water was also a concern. The totalproduction cost in Kr/m3 is higher than expected and higher than sales price. In technicalterms, the plant has functioned well. However, there is a need to monitor more parameters inthe plant including; more flow parameters, concentrations of added chemicals and more waterquality parameters. Electricity consumption has been higher than expected. Control(throttling) valves in the brine reject are relatively large energy consumers and arecommendation is to investigate potential savings by changing them for pressure exchangevalves.<br>www.ima.kth.se
3
Mondamert, Leslie. "Seawater desalination, autopsy and cleaning of reverse osmosis membranes recovered from full-scale plants and pilot units." Poitiers, 2010. http://www.theses.fr/2010POIT2264.
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Guirguis, Mageed Jean. "Energy Recovery Devices in Seawater Reverse Osmosis Desalination Plants with Emphasis on Efficiency and Economical Analysis of Isobaric versus Centrifugal Devices." Scholar Commons, 2011. http://scholarcommons.usf.edu/etd/3135.
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With huge demands for potable water in regions lacking fresh water sources such as surface or ground water, various potential technologies have been explored for eliminating water shortage. Seawater emerged as a potential source and a major lifeline for such water-deprived areas. The development of seawater reverse osmosis (SWRO) technology proved to be a groundbreaking innovation, making it easier to extract pure water from seawater. Ever since its inception, SWRO technology has taken many leaps towards the development of energy efficient and high yielding systems. The reduction in energy consumption of desalination plants that were based on the SWRO technology emerged as a major driver of the technology revolution in this field. The improvement of membrane life and salt rejection, increase in recovery, and decrease in energy consumption has been the primary criteria for sifting through available technologies for incorporation in desalination plants. Many developments have, ever since, occurred in this direction. The membrane life has multiplied and the Total Dissolved Solids in the product are now as low as 100 mg/L. In addition, recoveries of 40-50% have been achieved. By recycling energy, many SWRO desalination plants have significantly lowered their total energy consumption. With the help of energy recovery devices (ERDs), it is now possible to decrease power consumption and increase efficiency of the seawater reverse osmosis desalination plant.
The first large-scale municipal SWRO plant was installed in 1980 in Jeddah, Saudi Arabia. This plant consumed 8 kilowatt-hours energy per cubic meter of water produced. This consumed energy was less than half of what was usually consumed by other conventional distillation processes. However, the SWRO desalination technology has one disadvantage. The seawater, which is to be desalinated, is pressurized with the help of high-pressure pumps. A large amount of energy is consumed during this process. Once the desalination is complete, the remaining reject water has to be eliminated as waste. Since the brine reject produced in this process has a high pressure, simply dumping it back into the sea is a waste of energy. This pressure can be reused and thus, the energy could be recycled. This idea led to the innovation of energy recovery devices (ERDs) that prevent the wastage of energy in the SWRO process. The hydraulic energy in the highly pressurized reject brine can be re-used with the help of ERDs, and energy consumption can thus be reduced by significant high amounts. The development of ERDs helped in the set-up and operation of large-scale SWRO plants, and facilitated the economic viability of the desalination process. The energy requirements of conventional SWRO plants are presently as low as 1.6 kWh/m3, making the process more cost effective and energy efficient than other technologies. About 80% of the total cost of desalinated water is due to energy consumption and capital amortization. The remaining costs are associated with other maintenance operations such as replacement of membranes and other components, labor associated costs etc.
Since energy consumption is the main determinant of final costs of the product, increasing energy efficiency of the plants is of primary concern. This paper deals with various energy recovery devices such as the Francis turbine, Pelton wheel, turbocharger, Recuperator, DWEER and Pressure Exchanger, used in SWRO desalination plants along with case studies associated with each of these. Special focus is given to the energy efficiency and costs associated with these devices. A brief discussion of the devices that are currently under investigation is also provided in the conclusion.
An analysis of isobaric versus centrifugal devices is also conducted in this work. A comparison between the energy recovery turbine (ERT) manufactured by Pump Engineering Inc. (PEI) and the pressure exchanger (PX) manufactured by Energy Recovery Inc. (ERI) energy recovery systems is performed using collected data from provided water analyses and respective manufacturers' device specifications. The different configurations used for this comparison were applied to the Jeddah SWRO desalination plant for a total productivity of 240,000 m³/day. As a result of this analysis, the specific energy consumption of the ERT and PX configurations were 2.66 kWh/m3 and 2.50 kWh/m3 respectively. Analysis shows however that although the PX configuration achieved the best specific energy consumption, the ERT was favored over it due to its lower capital and maintenance costs. Therefore, the final conclusion of this work, in this special case, is that the ERT configuration is more economical than the PX configuration.
5
Thomson, A. Murray. "Reverse-osmosis desalination of seawater powered by photovoltaics without batteries." Thesis, Loughborough University, 2003. https://dspace.lboro.ac.uk/2134/10701.
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The design, construction and testing of a photovoltaic-powered reverse-osmosis (PV-RO) desalination system is presented. The system operates from seawater and requires no batteries, since the rate of production of freshwater varies throughout the day according to the available solar power. Initial testing of the system, with the modest solar resource available in the UK, provided freshwater at approximately 1.5 m³/day. Nearer to the equator and with a PV array of only 2.4 kWp, a software model of the system predicts production of over 3 m³/day throughout the year. The system employs a Clark pump brine-stream energy recovery mechanism and this, coupled with variable water recovery ratio, achieves a specific energy consumption of less than 4 kWh/m³ over a broad range of operation. Standard industrial inverters, motors and pumps are employed and provide good energy and cost efficiency. Maximum power point tracking (MPPT) for the photovoltaic array is provided by a novel control algorithm, developed by the author. Instrumentation and data acquisition of the hardware test rig using LabVIEW is described. Testing and modelling of the system components in MATLAB-Simulink is presented, together with a discussion of the full system modelling and design procedure, in which the aim was to minimise the cost of water. This led to a capital cost estimate of £23,055 includmg the PV array, and an overall cost of water, including full maintenance, of £2.00 per m³.
6
Bermudez-Contreras, Alfredo S. "An energy recovery device for small-scale seawater reverse osmosis desalination." Thesis, Loughborough University, 2010. https://dspace.lboro.ac.uk/2134/6098.
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This work presents the concept development, implementation and first practical demonstration of a new pressure intensifier for energy recovery in small-scale seawater reverse osmosis systems, and the simplified system configuration it requires. The new concept has great potential to reduce the specific energy consumption of small-scale seawater reverse osmosis systems. A mathematical analysis to study pressure intensifiers for energy recovery in reverse osmosis applications was developed. The analysis was used in the design and modelling of the energy recovery device. A first prototype was built and subsequently demonstrated in a system desalinating seawater over a wide range of electrical input power stretching between 286 and 1196 W, producing up to 286 L/h of freshwater with specific energy consumptions in the range of 3.5 to 4.5 kWh/m^3. The flat specific energy characteristic makes the device attractive for renewable-energy-powered systems without energy storage. The prototype implementation was realised through modifying a Clark pump, but the new concept is fundamentally different. The new device recovers energy from the concentrate stream, which it then uses to suck in and pressurise seawater, relying purely on its piston area ratio, and thus eliminating the need for a low-pressure feed pump.
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Hoffman, Anton Michael. "Design guidelines for a reverse osmosis desalination plant / Anton Michael Hoffman." Thesis, North-West University, 2008. http://hdl.handle.net/10394/4211.
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There are two basic needs globally and that is the control and supply of
reliable electricity and clean water. However, one of the biggest challenges
the world is facing today is the lack of fresh water resources. Lower rainfall,
together with population and industry growth, are only a few factors
contributing to the fast increasing strain on existing water supplies around the
world. This fast increasing need therefore necessitates the investigation into
finding alternative sources. One such option is that of desalination. In the last
50 years desalination technologies have been applied to produce high quality
fresh water from brackish and seawater resources. In the 1980's a breakthrough
was made with the introduction of the membrane desalination
technology, known as the reverse osmosis (RO) process.
Today newly developed technologies are improving the competitiveness of the
reverse osmosis process against the traditional distillation processes. There
are a number of options to increase the efficiency of a reverse osmosis plant
and one option is to use warm industrial waste water as the feed water to the
desalination plant. It is known that the viscosity of water is inversely
proportional to its temperature. Therefore, if the feed water temperature of a
reverse osmosis plant is increased the membranes will become more
permeable. This will result in a higher production volume or in a lower energy
demand. South Africa is on the edge of building the first fourth generation
nuclear power plant, called the Pebble Bed Modular Reactor (PBMR) at
Koeberg. The PBMR will produce a cooling water outlet temperature of 40°C
which can be used as feed water to a reverse osmosis plant.
In this study design guidelines of a reverse osmosis plant are given in nine
steps. These steps were then used during a basic component design of a
reverse osmosis plant coupled to the waste water stream of a PBMR nuclear
power plant. Furthermore design software programs were used to simulate
the coupling scheme in order to validate the outcome of the design guidelines.
The results of the two design approaches compared well to one another. It
furthermore showed that by using the waste water from the PBMR nuclear
power plant the efficiency of the RO plant is increased and the operating cost
is decreased. Fresh water can be produced at a cost of R 5.64/m3 with a
specific electricity consumption of 2.53 kWh/m3.<br>Thesis (M.Ing. (Nuclear Engineering)--North-West University, Potchefstroom Campus, 2009.
8
Hashim, Ahmed. "Foulants investigations and performance modelling analyses in seawater reverse osmosis (SWRO) desalination." Thesis, University of Newcastle Upon Tyne, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.489274.
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The research was mainly concerned with performance analysis in seawater reverse osmosis desalination at the Addur SWRO Desalination Plant, Kingdom of Bahrain; there were four main objectives associated with the research. The first objective was conducting a process performance analysis of the conventional pre-treatment system at the Addur Plant so as to determine its filtration efficiency (Chapter 4). The analysis involved assessment of principal filtration parameters like temperature, silt density index (SDI) and turbidity for one seasonal year (with reference to total organic carbon (TOC), ultra violet absorbance (UVA), humic acids substances (HAS) and total suspended solids (TSS) that reflect the fouling potential of organic matter in the seawater feed). Through the evaluation of these parameters' time varying profile trends, specific key aspects were acknowledged. It was established that the incoming seawater quality is characterised as complex and most difficult seawater feed utilised for seawater RO desalination and confirmed that the , pre-treatment was unable to meeting its design performance parameters (i.e. reduce the raw seawater SDI to 2.7 and remove organic matter). Seeping of various undesirable matter through the pre-treatment was verified through EDX analysis suggesting filtration channelling. A system shortfall in the pre-treatment process was conclusive. It was a~so recognised from the profile trends that SDI and turbidity were influenced by seawater . temperature, as micro-organisms flourish within high temperature regions. The second objective was carrying out comprehensive performance analyses on three leading RO membrane modules in seawater desalination tested at similar seasonal conditions and seawater feed composition (Chapter 5) through which the most suitable module that withstood the harsh operation conditions was selected to replace the existing membrane modules at the Addur Plant (where the design aspects and operating guidelines for the three modules were also reviewed in Chapter 3). The results demonstrated that Toyobo CTA HF was best suitable and FilmTec spiral wound PA composite proven second suitable while the performance operation and endurance of DuPont HFF PA was not acceptable. both did not exactly correlate to one another owing to the unavailability of the salt concentration in the vicinity of the membrane wall during the actual RO process. In the second model variations in water and salt transport within a seawater RO module during RO were established in terms of flow, pressure and seawater feed concentration traversing through the module. Fundamental parameters to seawater RO processes were determined such as pure water permeability constant (A), mole fraction of concentrated boundary solution (XA2), solute transport parameter ((DAwKO)sw), mass transfer coefficient for seawater on the high pressure side of the membrane (ks»1, concentration polarisation modulus (M) and thickness of concentrated boundary solution (I). All these quantities are unique and not before determined for real seawater RO systems. The third modelling analysis was concerned with developing a mathematical model defining spatial variations in key parameters ofthe seawater feed entering and traversing through the RO module; this was performed in terms of seawater feed temperature,. volumetric permeate flow rate (and related velocity) and the volumetric flow rate, pressure and concentration of solutions on the high pressure side of the membrane during RO separation. The results achieved through this research have been of primary significance to the development of the pre-treatment and seawater RO process operations and systems at the Addur SWRO Desalination Plant while the consequences of the solutio.ns recommended henceforth had reshaped the configuration of the plant, enhanced production and ensured availability and reliability.
9
Martinez, Hiroki. "Design of a desalination plant : aspects to consider." Thesis, University of Gävle, Faculty of Engineering and Sustainable Development, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-6995.
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<p>One of the main problems our actual society faces is the shortage of water. Despite the great effort made by authorities and researchers, multiple countries with poor economic resources are experiencing serious difficulties derivative of water scarcity. Desalination provides a feasible solution for inland and coastal areas. Through literature and reviewed articles analysis the reader will meet the actual issues regarding designing a desalination plant, and more over with reverse osmosis (RO) processes, which are the main arguments of this work. One of the big deals is the environmental concern when handling the concentrate disposal. Another important point about desalination processes is the increasingly interest in coupling the units with renewable energy sources (RES). The results point out that regardless of the efforts made until today, additional achievement is required in fields such as membrane’s structure materials for RO method, concentrate disposal systems, governmental water policies review and update, and greater distinction researches between brackish water and seawater RO desalination processes. Taking into consideration the previous outcomes it is finally concluded that some particular steps must be accomplished when beginning a desalination plant design.</p>
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Nagaraj, Veena. "Investigation and control of biofouling in seawater reverse osmosis desalination membranes by bacteria and their extracellular polysaccharides." Thesis, Nagaraj, Veena (2017) Investigation and control of biofouling in seawater reverse osmosis desalination membranes by bacteria and their extracellular polysaccharides. PhD thesis, Murdoch University, 2017. https://researchrepository.murdoch.edu.au/id/eprint/37865/.
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Biofouling in seawater reverse osmosis desalination membranes is a phenomenon that needs urgent solutions to effectively mitigate the problem, mainly due to huge economic losses it incurs. To achieve this, a thorough understanding of the microbial community ecology and source of fouling organisms on RO membranes is important. Extracellular polysaccharides produced by bacteria form an important part of the biofilm matrix that govern physical properties and structural integrity of the biofilm. Information about the chemical composition of exopolysaccharides is necessary to employ good control methods. The objectives of this research were defined to better understand biofouling, especially with respect to polysaccharide fouling, and investigate control methods.
They were achieved as follows i) Bacterial communities on industrially fouled RO membranes were characterized by next generation sequencing (NGS) on the Illumina Miseq platform; comparisons of microbial ecology were made between treatment groups of membrane samples. ii) Bacteria were isolated from membranes, prefilters and upstream locations of a full-scale desalination plant, and identified by 16S rRNA gene sequencing, matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) and Biolog Gen III systems. Suitable models were then selected from the culture collection based on their dominance in the genetic biofilm community. iii) Exopolysaccharides of model bacteria were purified by acetone precipitation methods and characterized by ion chromatography, Attenuated total reflectance-Fourier transformed infrared spectroscopy (ATR-FTIR) and enzyme linked lectin assay. iv) 2,2-dibromo-3-nitrilopropionamide (DBNPA), a biocide, and two free radical generating compounds, sodium nitroprusside (SNP) and xanthine oxidase, were tested as control agents to disperse biofilms by degrading polysaccharides on industrially fouled membranes. v) For potential use in biological control, bacterial isolates were screened for production of oxidizing enzymes using a xanthine oxidase nitroblue tetrazolium assay.
The major findings of this research that contribute to scholarly knowledge are:
i) The bacterial community on RO membranes was identified as being dominated by certain bacterial groups, which are known to be associated with unique biofilm forming abilities; mainly Caulobacterales, known to attach irreversibly with holdfast; Sphingobacterales, Rhizobiales and Sphingobacteriia that are known to produce glycosphingolipids; Burkholderiales, known for nitrate-reduction; and Pseudomonadales, proposed to be both primary and secondary colonizers, based on the literature.
ii) The cultured bacterial population were dominated by Gammaproteobacteria. MALDI-TOF and 16S rRNA gene sequencing were the most efficient identification methods. The model bacteria were good representatives of biofouling organisms in large scale, within limitations of culture bias.
iii) Polysaccharide structures of bacterial isolates revealed the presence of some rare sugars, which are known to form critical components of strong biofilms.
iv) Free-radical-generating compounds, SNP and xanthine oxidase, were more effective than the biocide DBNPA in alleviation of fouling by degrading polysaccharides.
v) Some bacterial strains like Microbacterium and Exiguobacterium produced xanthine oxidase to significant levels when exposed to hypoxanthine.
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Vishwanathappa, Manohar D. "Desalination of seawater using a high-efficiency jet ejector." Thesis, Texas A&M University, 2003. http://hdl.handle.net/1969.1/2463.
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The ability to produce potable water economically is the primary focus of seawater desalination research. There are numerous methods to desalinate water, including reverse osmosis, multi-stage flash distillation, and multi-effect evaporation. These methods cost more than potable water produced from natural resources; hence an attempt is made in this research project to produce potable water using a modified high-efficiency jet ejector in vapor-compression distillation. The greater efficiency of the jet ejector is achieved by properly mixing propelled and motive streams. From experiments conducted using air, the pressure rise across the jet ejector is better in case of one or two mixing vanes and the highest back pressure (pinch valve closed 83.33%). At other pinch valve closings, the air velocity through the jet ejector was high, so the extra surface area from the mixing vanes caused excessive friction and lowered the efficiency.
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MendonÃa, Doglasse Ernesto. "Osmosis reverse plant powered by photovoltaic modules with MPPT and self regulated pressure valve." Universidade Federal do CearÃ, 2016. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=16455.
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Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico<br>This project presents a brackish water desalination plant via Reverse Osmosis (RO) powered
by Photovoltaic Modules (PV) with Maximum Power Tracking (MPPT) and a self â
regulating pressure valve. The developed unit is installed on Alternative Energy Laboratory
(LEA), which is located on the campus of PICI at Federal University of CearÃ. To extract
maximum power from the PV module a Buck type converter was developed for this
application. The Incremental Conductance algorithms (IncCond) is used. The MPPT
technique was simulated, tested and validated, showing an efficiency of 86.8%. An innovation
in this plant is the use of a self-regulating pressure valve installed in the concentrate output,
which ensures a smaller pressure and power variation in the pump that is responsible for
pressurizing the water to the membranes. The technical feasibility of the RO plant is checked
in two phases: one without the presence of the self- regulating pressure valve in the
concentrated output and other with the self-regulating pressure valve in the concentrated
output. The plant is tested for two salinity levels 1000 and 1500 mg/L of TDS (Total
Dissolved Solids) levels. These salinity levels chosen are commonly found in most brackish
water wells of the semi-arid region of Northeastern Brazil. For operation without selfregulating pressure valve the obtained average values are: recovery rate 8.03% (relation
between permeate flow and feed water flow), 151.7 L of daily production of drinking water
with 130 mg/L of TDS, specific energy consumption of 2.68 kWh/m3. For operation with
self-regulating pressure valve the obtained average values are: recovery rate 8.14%, 175.3 L
of daily production of drinking water with 120 mg/L of TDS, specific energy consumption of
2.56 kWh/m3. Thus the configuration system using the self â regulating valve showed better
results<br>O presente projecto apresenta uma planta de dessalinizaÃÃo de Ãgua salobra por osmose
reversa (OR) acionada por mÃdulos fotovoltaicos (FV) com seguimento de potÃncia mÃxima
(MPPT - Maximum Power Point Tracking) e vÃlvula autoreguladora de pressÃo. A planta
desenvolvida està instalada no LaboratÃrio de Energias Alternativas (LEA), situado no
Campus do PICI da Universidade Federal do CearÃ. Para extraÃÃo da mÃxima de energia do
mÃdulo FV foi desenvolvido um conversor do tipo Buck, usando a tÃcnica CondutÃncia
Incremental (CondInc). A tÃcnica de MPPT foi simulada, testada e validada, apresentando
uma eficiÃncia de 86,8% no seguimento do ponto de potÃncia mÃxima. Uma inovaÃÃo na
planta proposta à o uso de uma vÃlvula autoreguladora de pressÃo instalada na saÃda do
concentrado, que garante uma menor variaÃÃo de pressÃo e corrente eletrica na motobomba
responsÃvel por pressurizaÃÃo da Ãgua para as membranas. A planta de OR foi testada em
duas etapas: uma sem a presenÃa da vÃlvula auto-reguladora de pressÃo e a outra com a
vÃlvula, para uma Ãgua de alimentaÃÃo entre os nÃveis de salinidade de 1000 e 1500 mg/L de
STD (SÃlidos Totais Dissolvidos). Estes nÃveis de salinidade adotados sÃo geralmente
encontrados em poÃos com Ãgua salobra do semiÃrido do Nordeste do Brasil e noutros casos
maior 1500 mg/L de STD. Para a operaÃÃo sem a vÃlvula autoreguladora de pressÃo foram
obtidos os seguintes valores mÃdios: taxa de recuperaÃÃo 8,03%, produÃÃo de Ãgua potÃvel de
151,7 L/dia com 130 mg/L de STD, consumo especÃfico de energia de 2,68 kWh/m3.
Para a operaÃÃo com a vÃlvula autoreguladora de pressÃo foram obtidos os seguintes valores
mÃdios: taxa de recuperaÃÃo 8,14%, produÃÃo de Ãgua potÃvel de 175,3 L/dia com 120 mg/L
de STD, consumo especÃfico de energia de 2,56 kWh/m3.
No entanto a configuraÃÃo da planta operando com a vÃlvula autoreguladora de pressÃo
apresenta melhores resultados relativamente a operaÃÃo sem a vÃlvula.
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Beery, Matan [Verfasser], and Günter [Akademischer Betreuer] Wozny. "Novel Sustainable Concepts in Process Design and Assessment of Seawater Reverse Osmosis Desalination Pre-treatment / Matan Beery. Betreuer: Günter Wozny." Berlin : Universitätsbibliothek der Technischen Universität Berlin, 2013. http://d-nb.info/1031993754/34.
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Alemi, Mehrnoosh. "The effect of wind fluctuations on the membrane of a stand-alone wind powered seawater Reverse Osmosis (RO) desalination unit." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2019. https://ro.ecu.edu.au/theses/2243.
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Water is one of the most important elements in human life. The major sources of water are defined as seawater, which cannot be used in many applications unless it gets desalinated. In this regard, investigations and developments for defining new economical and beneficial technologies in desalination methods have become more significant.
In this research, the influence of wind power fluctuations on Reverse Osmosis (RO) membrane lifetime, in terms of variations in membrane inlet flowrate and/or pressure, was investigated experimentally. The RO membranes applied in this project,were spiral wound module, Model: DOW FILMTEC, SW30- 2521 used individually in the rig for each test.
The experiments were conducted using a modified lab-scale seawater RO unit (CE-530) from GUNT Hamburg company. A variable speed positive displacement pump and two actuated step motor valves were applied in the rig to facilitate the required wind fluctuations.
At the first stage of this research, some initial experiments were accomplished to find the basic requirements of the fluctuating tests. Afterwards, three series of experiments were conducted each on an individual s new membrane to analyze the effect of fluctuating flowrate and/or pressure on their lifespan. A sample wind fluctuating pattern was followed in all three sets of tests. Based on the requirements of each test, three remote-control system were programmed using LABVIEW software, each used for the specified test. Each test was performed for 7 weeks (5 working days), 4 hours a day (140 hours). Deterioration mechanism of the membranes was monitored by measuring target parameters in two constant flow conditions weekly (after 20 hours of fluctuating operation) for each test. By comparing the results, the influence of flowrate and/or pressure fluctuations on membrane lifespan was evaluated.
Accomplishing the fluctuating experiments, structural deterioration of the membranes was investigated using Scanning Electron Microscope (SEM) tests comparing them with the original structure of a brand new membrane. These results could not give a justifiable conclusion on the membranes deterioration mechanism. Therefore, the conclusion was derived based on the membrane operational monitoring curves.
The results of this research would be significant in reducing costs of a stand-alone wind powered RO desalination process by elimination of intermediate energy storage.
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Casimir, Justin. "TECHNO-ECONOMIC ANALYSIS OF A PHOTOVOLTAIC POWER PLANT SUPPLYING ELECTRICITY FOR A LARGE SCALE REVERSE OSMOSIS DESALINATION UNIT IN AGADIR, MOROCCOJustin Casimir." Thesis, Högskolan i Gävle, Akademin för teknik och miljö, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-14833.
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Legislation about the water use in Morocco including the watering of green spaces is about to change. Indeed, the watering of green spaces will have to be made from waste water treatment plant. This report focuses on a golf course located in Agadir which is subject to the new regulation. The option studied through this paper is the desalination of salt water powered by solar energy. This paper focuses specifically on the generation of solar energy. The aim of the report is to compare the levelized cost of water express in €/m3 for three different alternatives: A) water from the drinking water plant; B) water from a reverse osmosis desalination plant driven by electricity from the national grid; C) water from a reverse osmosis desalination plant driven mainly by solar energy and some electricity from the national grid.The paper will first present the boundary conditions for the case study (part I), the technical analysis (part II-A & B) and then the economic analysis (part II-C). Part III presents the results, based on the simulation results from the software PVsyst, for both the technical and economic analysis and part IV explains the technical part in more detail.In the conclusion, the writer of the report would recommend to another in depth economic analysis in few years as the capital cost for the system with the reverse osmosis desalination plant and the photovoltaic plant is at the moment too high. However, regarding at the levelized cost of water, this case study become competitive with the other alternative. Moreover, looking at the environmental issues (water depletion, greenhouse gas emission) one could decide to take action and therefore take some economic risks.
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Sassi, Kamal M. "Optimal scheduling, design, operation and control of reverse osmosis desalination : prediction of RO membrane performance under different design and operating conditions, synthesis of RO networks using MINLP optimization framework involving fouling, boron removal, variable seawater temperature and variable fresh water demand." Thesis, University of Bradford, 2012. http://hdl.handle.net/10454/5671.
Full textAbstract:
An accurate model for RO process has significant importance in the simulation and optimization proposes. A steady state model of RO process is developed based on solution diffusion theory to describe the permeation through membrane and thin film approach is used to describe the concentration polarization. The model is validated against the operation data reported in the literature. For the sake of clear understanding of the interaction of feed temperature and salinity on the design and operation of RO based desalination systems, simultaneous optimization of design and operation of RO network is investigated based on two-stage RO superstructure via MINLP approach. Different cases with several feed concentrations and seasonal variation of seawater temperature are presented. Also, the possibility of flexible scheduling in terms of the number of membrane modules required in operation in high and low temperature seasons is investigated A simultaneous modelling and optimization method for RO system including boron removal is then presented. A superstructure of the RO network is developed based on double pass RO network (two-stage seawater pass and one-stage brackish water pass). The MINLP problem based on the superstructure is used to find out an optimal RO network which will minimize the total annualized cost while fulfilling a given boron content limit. The effect of pH on boron rejection is investigated at deferent seawater temperatures. The optimal operation policy of RO system is then studied in this work considering variations in freshwater demand and with changing seawater temperature throughout the day. A storage tank is added to the RO layout to provide additional operational flexibility and to ensure the availability of freshwater at all times. Two optimization problems are solved incorporating two seawater temperature profiles, representing summer and winter seasons. The possibility of flexible scheduling of cleaning and maintenance of membrane modules is investigated. Then, the optimal design and operation of RO process is studied in the presence of membrane fouling and including several operational variations such as variable seawater temperature. The cleaning schedule of single stage RO process is formulated as MINLP problem using spiral wound modules. NNs based correlation has been developed based on the actual fouling data which can be used for estimating the permeability decline factors. The correlation based on actual data to predict the annual seawater temperature profile is also incorporated in the model. The proposed optimization procedure identified simultaneously the optimal maintenance schedule of RO network including its design parameters and operating policy. The steady state model of RO process is used to study the sensitivity of different operating and design parameters on the plant performance. A non-linear optimization problem is formulated to minimize specific energy consumption at fixed product flow rate and quality while optimizing the design and operating parameters. Then the MINLP formulation is used to find the optimal designs of RO layout for brackish water desalination. A variable fouling profile along the membrane stages is introduced to see how the network design and operation of the RO system are to be adjusted Finally, a preliminary control strategy for RO process is developed based on PID control algorithm and a first order transfer function (presented in the Appendix).
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Oliveira, Fernando Freitas de. "Avaliação de filtros lentos de areia como pré-tratamento para o controle de biofouling em plantas de osmose reversa aplicadas na dessalinização de água do mar." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/87/87131/tde-12062013-143346/.
Full textAbstract:
O presente trabalho avaliou o desempenho de um sistema de pré-tratamento para água do mar constituído por um filtro lento de areia, com uma etapa prévia de filtração por um filtro de discos. O sistema demonstrou eficiência na remoção de fatores causadores de fouling em membranas de osmose reversa, removendo aproximadamente 97% dos sólidos suspensos totais presentes na água bruta, e gerando um filtrado com turbidez entre 0.1 e 0.2 UNT. As concentrações de microrganismos e AOC, principais fatores causadores da formação de biofouling, foram ambas reduzidas em cerca de 90%. Em sistemas de dessalinização de água do mar por osmose reversa, o pré-tratamento da água de alimentação constitui a principal estratégia no controle da formação do biofouling, que é gerado pelo estabelecimento de biofilmes sobre a superfície da membrana. A formação de biofouling gera impacto no desempenho do processo de osmose reversa e nos custos de operação.<br>This study evaluated the performance of a pretreatment system for seawater comprising of a slow sand filter, with a preliminary stage of filtration by disc filtration system. The system proved to be efficient in removing factors causing fouling in reverse osmosis membranes removing around 97% of the total suspended solids present in the raw water, and yielding a filtrate with turbidity between 0.1 and 0.2 NTU. The bacterial concentrations and AOC, main factors causing biofouling formation, were both reduced by about 90%. In seawater reverse osmosis systems, pretreatment of the feeded water is the main strategy to control biofouling, which is formed by the establishment of biofilms on a membrane surface. The biofouling formation produces an impact in the performance of the reverse osmosis process and operating costs.
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Sassi, Kamal M., and Iqbal M. Mujtaba. "Optimal operation of RO system with daily variation of freshwater demand and seawater temperature." Thesis, 2013. http://hdl.handle.net/10454/9723.
Full textAbstract:
no<br>The optimal operation policy of flexible RO systems is studied in this work. The design and operation of RO process is optimized and controlled considering variations in water demands and changing seawater temperature throughout the day. A storage tank is added to the system layout to provide additional operational flexibility and to ensure the availability of freshwater to customer at all times. A steady state model for the RO process is developed and linked with a dynamic model for the storage tank. The membrane modules are divided into a number of groups to add flexibility in operation to RO network. The total operating cost of the RO process is minimized in order to find the optimal layout and operating variables at discreet time intervals for three design scenarios. (C) 2013 Elsevier Ltd. All rights reserved.
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Patroklou, G., Kamal M. Sassi, and Iqbal M. Mujtaba. "Simulation of boron rejection by seawater reverse osmosis desalination." 2013. http://hdl.handle.net/10454/9711.
Full textAbstract:
yes<br>Boron is a vital element for growth of creations, but excessive exposure can cause detrimental effects to plants,
animals, and possibly humans. Reverse Osmosis (RO) technique is widely used for seawater desalination as well
as for waste water treatment. The aim of this study is to identify how different operating parameters such as pH,
temperature and pressure can affect boron concentrations at the end of RO processes. For this purpose, a
mathematical model for boron rejection is developed based on solution-diffusion model which can describe
solvent and solute transport mechanism through the membranes. After a wide and thorough research, empirical
correlations developed in the past are filtered, adopted and calibrated in order to faction with reliability as part of
the solution-diffusion model of this work. The model is validated against a number of experimental results from the
literature and is used in further simulations to get a deeper insight of the RO process. The general findings of the
boron rejection model are supporting the case that with increasing pH and operating pressure of the feed water,
the boron rejection increases and with increasing feed water temperature the boron rejection decreases.
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Patroklou, G., and Iqbal M. Mujtaba. "Economic optimisation of seawater reverse osmosis desalination with boron rejection." 2014. http://hdl.handle.net/10454/10765.
Full textAbstract:
No<br>Reverse Osmosis (RO) process is widely used for seawater desalination. In this work, we considered a small scale SWRO (Spiral Wound Reverse Osmosis) desalination unit which is enough to cover the need of a medium size hotel complex at Limassol city in Cyprus. The pH of the seawater in the region is 7.95 and the temperature varies from 17 to 27 °C. The aim of this study is to identify the configuration of the RO process and the optimum operating parameters such as pH and pressure that can minimise the total annualised cost of the process subject to acceptable quality of freshwater in terms of boron concentrations throughout the year. For this purpose, the mathematical model for boron rejection developed earlier by the authors is used but incorporates cost functions. The model is based on solution-diffusion model which can describe solvent and solute transport mechanism through the membranes. With the variation of seasonal seawater temperature, the key finding of this study was that by choosing the right combination of pH and pressure, substantial economical savings up to 16 % could be achieved.
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Khan, Muhammad T. "Fouling of Seawater Reverse Osmosis (SWRO) Membrane: Chemical and Microbiological Characterization." Diss., 2013. http://hdl.handle.net/10754/311061.
Full textAbstract:
In spite of abundant water resources, world is suffering from the scarcity of usable water. Seawater Reverse Osmosis (SWRO) desalination technology using polymeric membranes has been recognized as a key solution to water scarcity problem. However, economic sustainability of this advanced technology is adversely impacted by the membrane fouling problem.
Fouling of RO membranes is a highly studied phenomenon. However, literature is found to be lacking a detailed study on kinetic and dynamic aspects of SWRO membrane fouling. The factors that impact the fouling dynamics, i.e., pretreatment and water quality were also not adequately studied at full–scale of operation.
Our experimental protocol was designed to systematically explore these fouling aspects with the objective to improve the understanding of SWRO membrane fouling mechanisms. An approach with multiple analytical techniques was developed for fouling characterization. In addition to the fouling layer characterization, feed water quality was also analysed to assess its fouling potential. Study of SWRO membrane fouling dynamics and kinetics revealed variations in relative abundance of chemical and microbial constituents of the fouling layer, over operating time. Aromatic substances, most likely humic–like substances, were observed at relatively high abundance in the initial fouling layer, followed by progressive increase in relative abundances of proteins and polysaccharides. Microbial population grown on all membranes was dominated by specific groups/species belonging to different classes of Proteobacteria phylum; however, similar to abiotic foulant, their relative abundance also changed with the biofilm age and with the position of membrane element in RO vessel.
Our results demonstrated that source water quality can significantly impact the RO membrane fouling scenarios. Moreover, the major role of chlorination in the SWRO membrane fouling was highlighted. It was found that intermittent mode of chlorination is better than continuous mode of chlorination of seawater, as anti–biofouling strategy. It was also confirmed that significant biofilm development was inevitable even with the use of chlorine to disinfect SWRO membranes.
Our findings on the dynamic patterns of SWRO membrane fouling should help in further elaborating research projects focusing on the development of better strategies to minimize this troublesome phenomenon.
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Alnouri, Sabla. "The Development of a Synthesis Approach for Optimal Design of Seawater Reverse Osmosis Desalination Networks." Thesis, 2012. http://hdl.handle.net/1969.1/ETD-TAMU-2012-08-11887.
Full textAbstract:
This work introduces a systematic seawater reverse osmosis (SWRO) membrane network synthesis approach, based on the coordinated use of process superstructure representations and global optimization. The approach makes use of superstructure formulations that are capable of extracting a globally optimal design as a performance target, by taking into consideration desired process conditions and constraints that are typically associated with reverse osmosis systems. Thermodynamic insights are employed to develop lean network representations so that any underperforming solutions can be eliminated a priori. This essentially results in considerable improvement of the overall search speed, compared to previously reported attempts. In addition, the approach enables the extraction of structurally different design alternatives. In doing so, distinct membrane network design classes were established by partitioning the search space, based on network size and connectivity. As a result, corresponding lean superstructures were then systematically generated, which capture all structural and operational variants within each design class. The overall purpose is thus to enable the extraction of multiple distinct optimal designs, through global optimization. This mainly helps provide design engineers with a better understanding of the design space and trade-offs between performance and complexity.
The approach is illustrated by means of a numerical example, and the results obtained were compared to previously related work. As anticipated, the proposed approach consistently delivered the globally optimal solutions, as well as alternative efficient design candidates attributed to different design classes, with reduced CPU times.
This work further capitalizes on the developed representation, by accounting for detailed water quality information, within the SWRO desalination network optimization problem. The superstructures were modified to incorporate models that capture the performance of common membrane elements, as predicted by commercially available simulator tools, e.g. ROSA (Dow) and IMSDesign (Hydranautics). These models allow tracing of individual components throughout the system. Design decisions that are supported by superstructure optimization include network size and connectivity, flow rates, pressures, and post treatment requirements. Moreover, a detailed economic assessment capturing all the significant capital and operating costs associated in SWRO processes, including intake, pre and post treatment has also been accounted for. These modifications were then illustrated using a case study involving four seawater qualities, with salinities ranging from 35 to 45 ppt. The results highlight the dependency of optimal designs on the feed water quality involved, as well as on specified permeate requirements.
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Sassi, Kamal M., and Iqbal M. Mujtaba. "MINLP based superstructure optimization for boron removal during desalination by reverse osmosis." Thesis, 2013. http://hdl.handle.net/10454/9722.
Full textAbstract:
no<br>In this work, a model based MINLP (mixed integer nonlinear programming) optimisation framework is developed for evaluating boron rejection in a reverse osmosis (RO) desalination process. A mathematical model (for the RU process) based on solution diffusion model and thin film theory is incorporated in the optimisation framework. A superstructure of the RU network is developed which includes two passes: (a) seawater pass containing normal two-stage RU system housing seawater membrane modules and (b) the brackish water pass (BW) accommodating brackish water membrane modules. For fixed freshwater demand, the objective of this work is to demonstrate the effectiveness of the MINLP approach for analyzing and optimizing the design and operation of RU network while attaining desired limit on boron concentration in the freshwater produced. The effect of seasonal variation in seawater temperature and pH on boron removal efficiency is also discussed.
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Al-Obaidi, M. A., G. Filippini, F. Manenti, and Iqbal M. Mujtaba. "Cost evaluation and optimisation of hybrid multi effect distillation and reverse osmosis system for seawater desalination." 2019. http://hdl.handle.net/10454/16787.
Full textAbstract:
Yes<br>In this research, the effect of operating parameters on the fresh water production cost of hybrid Multi Effect Distillation (MED) and Reverse Osmosis (RO) system is investigated. To achieve this, an earlier comprehensive model developed by the authors for MED + RO system is combined with two full-scale cost models of MED and RO processes collected from the literature. Using the economic model, the variation of the overall fresh water cost with respect to some operating conditions, namely steam temperature and steam flow rate for the MED process and inlet pressure and flow rate for the RO process, is accurately investigated. Then, the hybrid process model is incorporated into a single-objective non-linear optimisation framework to minimise the fresh water cost by finding the optimal values of the above operating conditions. The optimisation results confirm the economic feasibility of the proposed hybrid seawater desalination plant.
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Lee, Shang-Tse. "Effectiveness of seawater reverse osmosis (SWRO) pretreatment systems in removing transparent exopolymer particles (TEP) substances." Thesis, 2015. http://hdl.handle.net/10754/553067.
Full textAbstract:
Transparent exopolymer particles (TEP) have been reported as one of the main factors of membrane fouling in seawater reverse osmosis (SWRO) process. Research has been focused on algal TEP so far, overlooking bacterial TEP. This thesis investigated the effects of coagulation on removal of bacterial TEP/TEP precursors in seawater and subsequent reduction on TEP fouling in ultrafiltration (UF), as a pretreatment of SWRO. Furthermore, the performance of pretreatment (coagulation + UF) has been investigated on a bench-scale SWRO system. TEP/TEP precursors were harvested from a strain of marine bacteria, Pseudoalteromonas atlantica, isolated from the Red Sea. Isolated bacterial organic matter (BOM), containing 1.5 mg xanthan gum eq./L TEP/TEP precursors, were dosed in Red Sea water to mimic a high TEP concentration event. Bacterial TEP/TEP precursors added to seawater were coagulated with ferric chloride and aluminum sulfate at different dosages and pH. Results showed that ferric chloride had a better removal efficiency on TEP/TEP precursors.
Afterwards, the non-coagulated/coagulated seawater were tested on a UF system at a constant flux of 130 L/m2h, using two types of commercially available membranes, with pore sizes of 50 kDa and 100 kDa, respectively. The fouling potential of coagulated water was determined by the Modified Fouling Index (MFI-UF). Transmembrane pressure (TMP) was also continuously monitored to investigate the fouling development on UF membranes. TEP concentrations in samples were determined by the alcian blue staining assay. Liquid chromatography-organic carbon detection (LC-OCD) was used to determine the removal of TEP precursors with particular emphasis on biopolymers.
Finally, SWRO tests showed that TEP/TEP precursors had a high fouling potential as indicated by MFI-UF, corresponding to the TMP measurements. Coagulation could substantially reduce TEP/TEP precursors fouling in UF when its dosage was equal or higher than 0.2 mg Fe/L. The flux decline experiments showed that coagulation + UF pretreated water had a smaller fouling potential than MF pretreated water. This thesis also provides useful and practical information on controlling bacterial TEP/TEP precursors fouling in UF and RO systems.
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Al-Obaidi, M. A., A. A. Alsarayreh, A. M. Al-Hroub, S. Alsadaie, and Iqbal M. Mujtaba. "Performance analysis of a medium-sized industrial reverse osmosis brackish water desalination plant." 2018. http://hdl.handle.net/10454/16400.
Full textAbstract:
Yes<br>The implementation of Reverse Osmosis (RO) technology is noticeably increased to produce freshwater from brackish and seawater resources. In this work, performance analysis of a multistage multi pass medium-sized spiral wound brackish water RO (BWRO) desalination plant (1200 m³/day) of Arab Potash Company (APC) located in Jordan is evaluated using modelling and simulation. For this purpose, a mathematical model for the spiral wound RO process based on the principles of solution diffusion model is developed. The model is then used to simulate the operating conditions of low-salinity brackish water RO (BWRO) desalination plant. The results obtained are then compared against the real industrial data of BWRO desalination plant of APC which shows a high-level of consistency. Finally, the model is used to analysis the impact of the operating parameters such as salinity, pressure, temperature, and flow rate on the plant performance. The sensitivity analysis confirms that both feed flow rate and operating pressure as the critical parameters that positively affect the product salinity.
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Alshahri, Abdullah. "A versatile approach for combined algae removal and biofouling control in seawater reverse osmosis (SWRO) desalination systems." Diss., 2021. http://hdl.handle.net/10754/668172.
Full textAbstract:
The goal of this study was to evaluate the feasibility of using advanced coagulation with
Fe(VI) in coagulation-flocculation-sedimentation/ flotation systems for the pretreatment
of SWRO desalination plants during algal bloom events.
Algal organic matter (AOM) material extracted from marine diatom species (Chaetoceros
affinis) was added to Red Sea water to mimic algal bloom conditions. Low dosage of
Fe(VI) (<1 mg Fe/L) was very effective at improving feed water quality containing AOM
(algal bloom conditions). Based on results from both a bench-scale DAF unit and Jar
testing unit, 0.75 mg Fe/L of Fe (VI) proved to be effective at improving the raw water
quality which is comparable to the performance of 1 and 3 mg Fe/L of Fe (III). The
removal efficiency for both testing units with the use of Fe(VI) was up to 100% for algae
, 99.99% for ATP, 99% for biopolymers and 70 % for DOC. The improvement in Fe(VI)
performance is related to the simultaneous action of Fe(VI) as oxidant, disinfectant and
coagulant.
The performance of Fe(VI) coagulant was also evaluated with the use of coagulant aids
(clays). The overall turbidity, DOC, biopolymers and algal cells removal was improved
via using Fe(VI) and clays at very low dose. Generally, it was found that for the same
pretreatment performance achieved, a much lower Fe(VI) dose was required compared to
Fe (III), which make it important to study of cost effectiveness for using Fe(VI) instead
of Fe(III) and estimate cost savings during algal bloom conditions.
A detailed cost comparative study was conducted for Fe(III) vs. Fe(VI) coagulation
process based on the removal efficiency. The use of Fe(VI) reduced the total pretreatment
cost by 77% and sludge disposal cost by > 88% compared to the use of Fe(III) in the
pretreatment process. The use of Fe(VI) reduces the operational and maintenance cost in
SWRO desalination plant by 7% and the production cost by 4%. This study proved that
the use of Fe(VI) during high turgidity and algal bloom conditions helped providing high
raw water quality to the RO process with lower chemicals and operations cost as well as
low chlorine and iron residuals.
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Filippini, G., M. A. Al-Obaidi, F. Manenti, and Iqbal M. Mujtaba. "Design and economic evaluation of solar-powered hybrid multi effect and reverse osmosis system for seawater desalination." 2019. http://hdl.handle.net/10454/17036.
Full textAbstract:
Yes<br>Reducing the cost of fresh water has always been a major concern in the desalination industry. A solar powered hybrid multi-effect distillation and reverse osmosis desalination plant (MED+RO) has been designed and optimised from an economical point of view in a previous work by the same authors. In the present study, the possibility of coupling the desalination plant with a photovoltaic (PV) solar farm is investigated, with the aim of generating electricity at low cost and in a sustainable way. A detailed mathematical model for the PV system has been implemented from the literature. Interestingly, the model can predict the cost of the PV system in terms of capital cost and electricity cost per kWh considering the input data of solar irradiation, duration of daylight and technical specification of a real solar module. Consequently, the solar PV model has been combined with the desalination model, which enables to estimate the cost of fresh water per cubic meter. Data about four locations, namely Isola di Pantelleria (IT), Las Palmas (ES), Abu Dhabi (UAE), and Perth (AUS), have been used to economically test the feasibility of installing the proposed plant, and especially of the PV solar farm.
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Barello, M., D. Manca, Rajnikant Patel, and Iqbal M. Mujtaba. "Operation and modelling of RO desalination process in batch mode." 2015. http://hdl.handle.net/10454/7943.
Full textAbstract:
Yes<br>The performance of a batch reverse osmosis (RO) desalination process in terms of permeate quantity and salinity as a function of feed pressure and feed salinity is evaluated by using laboratory experiments and process modelling. Special attention is paid to the water and salt permeability constants (Kw, Ks) which affect the permeate and salt flux across the membrane. Kw and Ks are found to be strongly pressure-dependent for the batch system which is in-line with earlier observations for continuous RO systems. However, the most important findings of this work are the dependence of Kw and Ks on feed salinity, something that have never been observed or reported in the literature. In order to better qualify these observations, further experiments with the batch system are conducted with a constant feed salinity so that the operating condition resembles that of a continuous RO process.
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Dehwah, Abdullah. "Feasibility of Gallery Intake Systems for Seawater Reverse Osmosis Facilities along the Northern Red Sea Coast of Saudi Arabia." Thesis, 2012. http://hdl.handle.net/10754/215929.
Full textAbstract:
The Kingdom of Saudi Arabia is dependent on desalination of seawater to provide new
water supplies for the future. Desalination is expensive and it is very important to reduce
the cost and lower the energy consumption. Most seawater reverse osmosis facilities use
open-ocean intakes, which require extensive pre-treatment processes to remove
particulate and biological materials that cause operating problems. An alternative intake
is the subsurface system which utilizes the concept of riverbank filtration using wells or
galleries and provides natural filtration to improve the quality of feedwater before it
enters the desalination plant. This reduces operating cost and lowers energy consumption.
Research was focused on evaluating gallery-type intakes (beach and seabed galleries)
that could be used along the Northern Red Sea shoreline to provide a better quality
feedwater for desalination. The geological characteristics of the visited sites were
favorable for the development of seabed filter systems (offshore), but not for beach
gallery intakes. The low wave energy along the shoreline and the presence of mud or
rocky coasts made beach galleries infeasible. One of the potentially favorable sites for a
seabed filter was located in the nearshore area at King Abdullah Economic City (KAEC).
This site has a predominantly sandy offshore bottom with shallow water depths, and a
low tide range. In addition, the bottom is always covered with water and contains soft
limestone unit below the sand mantle that could be easy excavated to facilitate the construction of a seabed filter. About 50 sediment samples were collected from the site
and laboratory measurements were performed on them. Grain size distribution, porosity
and hydraulic conductivity measurements were performed on the sediment samples. In
addition, six statistical methods were used to estimate the hydraulic conductivity values.
Based on results of lab measurements, field observations, tide ranges and sediment types,
it is concluded that the geological conditions and characteristics of KAEC site are
feasible for design and construction of a seabed filtration system. A conservatively
designed cell with dimensions of 100 by 50 m would produce about 25,000 m3/day of
filtered seawater and seven cells could support a 60,000 m3/day (permeate) seawater RO plant.
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Albassam, Hassah. "Characterization of full-scale KAUST RO desalination plant and RO produced drinking water." Thesis, 2021. http://hdl.handle.net/10754/669016.
Full textAbstract:
Water samples were taken at the KAUST RO plant, the WDRC pilot plant and three other full-scale desalination installations in Saudi Arabia. The water was characterized using selected microbiological parameters, being conventional (heterotopic place count (HPC), total coliforms, Escherichia coli) and more novel and sensitive methods (adenosine tri-phosphate (ATP, a measure for bacterial activity), as well as total and intact bacterial cell concentrations (TDC using flow cytometry) and supporting parameters (pH, conductivity, residual chlorine and temperature). Selective samples were used to quantify the bacterial growth potential (“food for the bacteria”), applying a flow cytometer based easily Assimilable Organic Carbon (AOC) assay. Hypothesized was that no or very low bacterial numbers would occur after RO filtration in the plants due to the high rejection properties of the RO membranes and the produced water exceptionally low mineral and nutrient content. Key findings are that the (i) RO permeate contains bacterial cell concentrations exceeding 1.0 × 103 cells/mL. The highest percentage of cells are intact and active, based on the ATP and total cell counts (ii) advanced microbial parameters ATP and TDC enabled to detect and quantify bacteria numbers and activity while the less sensitive conventional plate counts based techniques did not, (iii) flow cytometer-based growth potential measurements indicate the presence of 8 µg AOC/L in the RO permeate. A typical last step in drinking water production is chlorination, effectively inactivating all the bacterial cells. The origin of the bacterial cells and the biodegradable nutrients enabling the bacterial growth in the RO permeate is not clear. There is a clear need to assess the origin of the nutrients and bacteria found in the RO produced water. It is not expected to be passing the RO membrane.
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Filippini, G., M. A. Al-Obaidi, F. Manenti, and Iqbal M. Mujtaba. "Performance analysis of hybrid system of multi effect distillation and reverse osmosis for seawater desalination via modeling and simulation." 2018. http://hdl.handle.net/10454/16586.
Full textAbstract:
Yes<br>The coupling of thermal (Multi Stage Flash, MSF) and membrane processes (Reverse Osmosis, RO) in desalination systems has been widely presented in the literature to achieve an improvement of performance compared to an individual process. However, very little study has been made to the combined Multi Effect Distillation (MED) and Reverse Osmosis (RO) processes. Therefore, this research investigates several design options of MED with thermal vapor compression (MED_TVC) coupled with RO system. To achieve this aim, detailed mathematical models for the two processes are developed, which are independently validated against the literature. Then, the integrated model is used to investigate the performance of several configurations of the MED_TVC and RO processes in the hybrid system. The performance indicators include the fresh water productivity, energy consumption, fresh water purity, and recovery ratio. Basically, the sensitivity analysis for each configuration is conducted with respect to seawater conditions and steam supply variation. Most importantly, placing the RO membrane process upstream in the hybrid system generates the overall best configuration in terms of the quantity and quality of fresh water produced. This is attributed to acquiring the best recovery ratio and lower energy consumption over a wide range of seawater salinity.
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Van, der Walt Philippus Johannes. "Thermodynamic optimisation of a boiler feed water desalination plant / Philippus Johannes van der Walt." Thesis, 2014. http://hdl.handle.net/10394/15674.
Full textAbstract:
In the process of electricity generation, water is used as the working fluid to transport energy from the fuel to the turbine. This water has to be ultrapure in order to reduce maintenance cost on the boilers.
For the production of ultrapure water, a desalination process is used. This process consists of an ultrafiltration pretreatment section, two reverse osmosis stages and a continuous electrodeionisation stage. Reverse osmosis desalination plants are, however, inherently inefficient with a high specific energy consumption. In an attempt to improve the efficiency of low recovery seawater applications, energy recovery devices are installed on the brine outlet of the reverse osmosis stages. The energy recovery device recovers the energy that is released through the high pressure brine stream and reintroduces it to the system.
The investigated desalination process has a fresh water feed with a salinity of 71 ppm and is operated at recoveries above 85%. The plant produces demineralised water at a salinity lower than 0.001ppm for the purpose of high pressure boiler feed.
A thermodynamic analysis determined the Second Law efficiencies for the first and second reverse osmosis sections as 3.85% and 3.68% respectively. The specific energy consumption for the reverse osmosis plants is 353 Wh/m3 and 1.31 Wh/m3. This was used as the baseline for the investigation. An exergy analysis determined that energy is lost through the brine throttling process and that a pressure exchanging system can be installed on all reverse osmosis brine streams. Energy recovery devices are untested in high recovery fresh water applications due to the low brine pressure and low brine flow.
It was determined that pressure exchanging systems can reduce the specific energy consumption of the first reverse osmosis stage with 12.2% whereas the second RO stage energy consumption can be improved with 7.7%. The Second Law efficiency can be improved by 25.6% for the first reverse osmosis stage while the efficiency is improved with 18.1% for the second stage. The optimal operating recovery for the PES is between 80% and 90%.<br>MIng (Chemical Engineering), North-West University, Potchefstroom Campus, 2015
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Rodríguez, Luis Raúl. "Feasibility Analysis of a Seabed Filtration Intake System for the Shoaiba III Expansion Reverse Osmosis Plant." Thesis, 2012. http://hdl.handle.net/10754/234971.
Full textAbstract:
The ability to economically desalinate seawater in arid regions of the
world has become a vital advancement to overcome the problem on
freshwater availability, quality, and reliability. In contrast with the major capital
and operational costs for desalination plants represented by conventional
open ocean intakes, subsurface intakes allow the extraction of high quality
feed water at minimum costs and reduced environmental impact. A seabed
filter is a subsurface intake that consists of a submerged slow sand filter, with
benefits of organic matter removal and pathogens, and low operational cost.
A site investigation was carried out through the southern coast of the
Red Sea in Saudi Arabia, from King Abdullah University of Science and
Technology down to 370 kilometers south of Jeddah. A site adjacent to the
Shoaiba desalination plant was selected to assess the viability of constructing
a seabed filter. Grain sieve size analysis, porosity and hydraulic conductivity
permeameter measurements were performed on the collected sediment
samples. Based on these results, it was concluded that the characteristics at
the Shoaiba site allow for the construction of a seabed filtration system.
A seabed filter design is proposed for the 150,000 m3/d Shoaiba III
expansion project, a large-scale Reverse Osmosis desalination plant. A filter
design with a filtration rate of 7 m/d through an area of 6,000 m2 is proposed to meet the demand of one of the ten desalination trains operating at the
plant. The filter would be located 90 meters offshore where hydraulic
conductivity of the sediment is high, and mud percentage is minimal. The thin
native marine sediment layer is insufficient to provide enough water filtration,
and consequently the proposed solution involves excavating the limestone
rock and filling it with different layers of non-native sand and gravel of
increasing grain size.
An initial assessment of the area around Shoaiba showed similar
sedimentological conditions that could lead into the application of comparable
seabed filter design concepts to supply the entire feed water requirement of
the plant. Considerations for the construction of a seabed filter should include
technical feasibility and life cycle assessment, i.e. capital costs, operating
costs and environmental impacts.
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Barello, M., D. Manca, Rajnikant Patel, and Iqbal M. Mujtaba. "Neural network based correlation for estimating water permeability constant in RO desalination process under fouling." 2014. http://hdl.handle.net/10454/10602.
Full textAbstract:
No<br>The water permeability constant, (K-w), is one of the many important parameters that affect optimal design and operation of RO processes. In model based studies, e.g. within the RO process model, estimation of W-w is therefore important There are only two available literature correlations for calculating the dynamic K-w values. However, each of them is only applicable for a given membrane type, given feed salinity over a certain operating pressure range. In this work, we develop a time dependent neural network (NN) based correlation to predict K-w in RO desalination processes under fouling conditions. It is found that the NN based correlation can predict the K-w values very closely to those obtained by the existing correlations for the same membrane type, operating pressure range and feed salinity. However, the novel feature of this correlation is that it is able to predict K-w values for any of the two membrane types and for any operating pressure and any feed salinity within a wide range. In addition, for the first time the effect of feed salinity on Kw values at low pressure operation is reported. Whilst developing the correlation, the effect of numbers of hidden layers and neurons in each layer and the transfer functions is also investigated. (C) 2014 Elsevier B.V. All rights reserved.
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CHEN, HUANG WEN, and 陳煌文. "Application of low reverse salt draw solution for PFO-20 FN forward osmosis combined with membrane distillation for seawater desalination." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/8ys23v.
Full textAbstract:
碩士<br>國立臺北科技大學<br>環境工程與管理研究所<br>107<br>FO is considered as a promising technology due to the advantages of low energy consumption and high solute rejection. This study presents the practical use of FO membranes for demonstrating a novel FO membrane configuration that can achieve desalination of seawater by means of reducing energy. Different concentrations of NaCl (5 g/L、 10 g/L、 20 g/L、 35 g/L ) solution has been utilized as feed water in FO system. In this study, commercial FO Module (PFO 20FN) was used to test the water flux of different draw solution such as ethylenediaminetetraacetic acid, magnesium sulfate and sodium phosphate. It is observed that water flux decreased steeply when the osmotic pressure gradient between the draw and feed solutions decreased due to the salt accumulation on the FO membrane surface.
In the second stage of this study, membrane distillation (MD) process was used to recover the diluted draw solution for reuse in the FO process. PTFE membrane with the pore size of 0.45 μm (thickness 0.22 mm) ,the pore size of 0.2μm (thickness 0.55mm、、0.18 mm), and pore size of 0.1 μm (thickness 0.55mm、、0.18 mm) are investigated in this study. The results indicate that the highest water flux (10.63L/m2h) were achieved by PTFE membrane with the pore size of 0.45 μm. The rejection of PTFE membrane with the pore size of 0.1 μm was found to be 100%. PTFE membrane with the thickness of 0.55 mm can reduce membrane wetting during long--term operation.
The hybrid FO--MD system was effectively applied to concentrate the draw solution to drinking water quality standards was achieved.