Dissertations / Theses: 'Reverse osmosis desalination'

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Harrison, Don. "Solar powered reverse osmosis desalination for remote communities." Thesis, Harrison, Don (1989) Solar powered reverse osmosis desalination for remote communities. Honours thesis, Murdoch University, 1989. https://researchrepository.murdoch.edu.au/id/eprint/40085/.

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Many Aboriginal Outstations in Western Australia have bores which produce drinking water of such a low standard that the health of the community members is at risk. Major concerns are the high concentrations of sale, nitrates and fluoride and bacteriological contamination. Communities faced with this problem have four choices. They can sink another bore nearby in the hope of finding better water, which would be expensive and not necessarily successful. They can physically move to another location which would be socially and culturally disruptive. They can accept the risk and drink the water untreated. Recent innovations in reserve osmosis desalination now make it possible to treat the water on site using solar power. The appropriateness of this new technology for remote locations is analysed. A means of predicting the power requirements of a unit capable of supplying the drinking water needs of a small community, estimated at up to 1 m3 per day is derived. A small commercially available unit was tested and it was found that in summer it could produce a steady flow of over 5 L/hour for 10 hours per day when used with a solar tracker and a power optimiser. Two designs were developed which could supply the desired 1 m3 flow rate from the power of two 55 W solar panels. A prototype of one design has been constructed and early testing demonstrate that is is capable of producing up to 400 L/day even at low pump efficiencies. Minor improvements are likely to substantially improve production in the near future.

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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.
Thesis (M.Ing. (Nuclear Engineering)--North-West University, Potchefstroom Campus, 2009.

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Xie, Zhangwang. "Polysaccharide fouling in reverse osmosis and forward osmosis desalination and its alleviation." Thesis, Xie, Zhangwang (2015) Polysaccharide fouling in reverse osmosis and forward osmosis desalination and its alleviation. PhD thesis, Murdoch University, 2015. https://researchrepository.murdoch.edu.au/id/eprint/31172/.

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Membrane separation processes, including forward osmosis (FO) and reverse osmosis (RO), for application in water desalination are plagued by membrane fouling. In particular, membrane biofouling is unpredictable in its nature and affected by numerous factors. One of the major contributors to biofouling is the extracellular polymeric substances (EPS) produced by bacteria, especially the polysaccharides that form a large part of EPS. The objectives of this study are to understand the polysaccharide fouling mechanisms based on a comparison of polysaccharide fouling in FO and RO and to find suitable alleviating agents for polysaccharide fouling mitigation. Three major tasks were conducted in this study. Firstly, polysaccharide fouling in FO and RO were compared under identical solution chemistry and operational conditions to understand the respective fouling mechanisms in FO and RO. Secondly, some alleviating agents for mitigation of polysaccharide fouling in FO and RO were tested to demonstrate the fouling alleviation mechanism. Thirdly, a model of hydraulic resistances was developed to illustrate membrane fouling mechanisms based on analysis of the contribution of hydraulic resistances to permeate flux decline. Major findings are: 1) Commercial polysaccharides and polysaccharides isolated from naturally adherent bacteria behaved differently in membrane fouling, which showed that alginate was not a typical model and it is important to select a proper model for polysaccharide fouling. 2) Under identical conditions, membrane fouling by both commercial and isolated polysaccharides was more severe in RO than FO, indicating the importance of pressure source in membrane fouling. 3) RO fouling was likely dominated by foulant – foulant interaction which was greatly affected by calcium ions, while FO fouling could be largely governed by foulant – membrane interaction, which was greatly influenced by solution viscosity. 4) Sodium nitroprusside (SNP) at a proper dose was found to be able to reduce membrane fouling, which could be explained by the electrostatic repulsion between polysaccharides and SNP. 5)Presence of calcium ions played a crucial role in polysaccharide fouling and its alleviation, with its presence leading to significant increase in cake resistance in RO fouling and reducing alleviation efficiency.

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Ashhuby, Bashir Ali. "Biofouling studies on reverse osmosis desalination of hypersaline waters." Thesis, University of Sheffield, 2007. http://etheses.whiterose.ac.uk/3599/.

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Biological fouling of reverse osmosis (RO) membranes is affected by many factors, and it is not clearly understood, especially with respect to hypersaline waters. Biofouling minimisation requires understanding of the fundamentals of the biofilm development. It is also necessary to monitor biofilm development at various stages and its relation to concentration polarisation phenomena. The two main goals were to explore the biological diversity of a hypersaline lake called "Qabar-Onn"t located in the Sahara; and to better understand what biotic and abiotic factors govem biofouling of RO membranes treating hypersaline waters. Three halotolerant bacterial strains (Euhalothece species, BAAOOl and BAA002, and Halomonas pantelleriensis species, BAA003) were isolated from the lake using conventional culturing methods, and were identified based on 16S rRNA sequencing. Two isolated species, Eukalothece species BAAOOI and Halomonas pantelleriensis species BAA003 were used as model microorganisms to evaluate the potential of biofilm development on RO membranes. Salinity and surface roughness, which affect biofilm initiation and growth, were investigated. A novel, in-situ monitoring device was used to detect initiation of biofilm formation, and its relation to solutes and concentrations near RO membrane surfaces. The results showed that Qabar-Onn Lake is inhabited by a wide range of microorganisms, which seem to have a strong potential to adapt to the rapid increase in the lake salinity. In addition to salinity, pH also is limiting factor on biodiversity and microorganisms' dominance. Biofouling was strongly controlled by membrane characteristics and feed salinity. Lower surface roughness and low salinity contributed to less biofilm formation. Furthermore, the absence of monovalent anions (i. e. chloride) in the feed enhanced flux at low salinities; however, its absence severely decreased flux at higher salinities. Similarly, microorganisms present in the feed extremely enhanced the permeate flux at low salinities, however, at high salinities the flux decreased in the presence of microorganisms.

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Harrison, Don. "Solar powered reverse osmosis desalination: Technology for remote communities." Thesis, Harrison, Don (2001) Solar powered reverse osmosis desalination: Technology for remote communities. PhD thesis, Murdoch University, 2001. https://researchrepository.murdoch.edu.au/id/eprint/52404/.

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The need for desalination to provide drinking water of acceptable standards has been established. A review of desalination techniques suggests that solar powered reverse osmosis with energy recovery is likely to satisfy the widest range of applications in inland Australia and elsewhere. Of the energy recovery techniques, the 'flow-regulated' approach appears well suited to remote applications, because it maintains its set recovery ratio regardless of insolation levels, and starts and stops automatically at sunrise and sunset. Operating and capital costs of units needs to be minimised and operational flexibility maximised for wide application in remote areas. This project aimed to develop, produce and test a low cost solar powered desalinator that was portable, reliable and flexible. The thesis describes the theoretical and practical development of a production model through the four prototypes. The prototypes were tested to determine the performance of a variety of membranes, the efficiency of the pumps and energy recovery system, and the water slippage of valves and seals. The available energy from the two-panel tracking array was also assessed. A model which describes the hydraulics of 'flow-regulated' energy recovery systems was developed and incorporated in a spreadsheet program and used to assess the performance of the prototypes. The relevance of all the variable components affecting fresh water production can be assessed through graphically presented results from the spreadsheet. A production model solar powered desalinator capable of 400 L/day from a 120 W peak array has been developed as a result of the project. The flow-regulated approach to energy recovery appears to work well in the field and may be contributing to the maintenance of high water production rates at all sites without resorting to chemical pretreatment or frequent cleaning. High pulsation rates and low feed flow rates through large diameter spiral wound membranes do not appear to adversely affect membrane life at the low pressures used in these machines. Further research is required to monitor the long term reliability and running costs of these machines, their degree of acceptance in remote communities, and their ability to maintain the quality of product water to acceptable standards.

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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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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.

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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.

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Wardeh, Sawsan. "Numerical modelling of reverse osmosis channels: application in desalination industry." Thesis, University of Nottingham, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.490836.

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Reverse osmosis (RO) is widely used for the production of drinking water from brackish and sea water. In the RO process, pressure is used to separate water and salts by allowing water to pass through a semi permeable membrane leaving the salts behind. Therefore, controlling membrane fouling will help keep the productivity high. Having spacer filaments in the feed channel has been shown to reduce the concentration polarisation on the surfaces of the membrane and therefore fouling. This thesis focuses on the simulation of multiphase flow in spacer-filled channels using computational fluid dynamics (CFD).

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Robinson, Roderick Q. "Desalination of groundwater using reverse osmosis coupled to a windmill." Thesis, Robinson, Roderick Q. (1990) Desalination of groundwater using reverse osmosis coupled to a windmill. Masters by Research thesis, Murdoch University, 1990. https://researchrepository.murdoch.edu.au/id/eprint/52405/.

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Reverse osmosis (RO) has the potential to fulfill the requirements of reliability, small size and low energy input suitable for remote area drinking water desalination by linking this technology to a standard multi-vane windmill pump. The research contained in this Masters thesis covers the design, construction, field testing and performance analysis of a prototype windpowered RO desalination system set up at a site near Murdoch University, Western Australia. The prototype was run from July 1988 for thirteen months, yielding 3348 hours of usable windspeed, direction input data, and desalinated water output data. This data has been analysed and the performance determined for the test site wind regime. Once performance data was obtained under the measured wind regime, a projection of expected performance using wind data from other areas was constructed to establish the performance of the system in remote settings. The performance projection is based on a production model using variables measured during the test period, which are quantified and matched to the wind characteristics of any site as determined by its windspeed distribution curve. All data is entered into a spreadsheet programme, which calculates the projected performance. Fouling by feedwater contaminants represents another area of potential problems in RO desalination. The Masters research seeks to address this problem by investigating fouling, both by a literature review and experimentation. The solution to the problem is to adopt a number of pretreatment systems and design solutions which minimize fouling in RO systems. The thesis draws together these two areas of investigation to predict the performance and pretreatment requirements for groundwater desalinations in a typical remote setting in Western Australia.

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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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Martinetti, C. Riziero. "Membrane contractor processes for desalination of brackish water reverse osmosis brines /." abstract and full text PDF (UNR users only), 2008. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1455665.

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Thesis (M.S.)--University of Nevada, Reno, 2008.
"May, 2008." Includes bibliographical references (leaves 35-38). Library also has microfilm. Ann Arbor, Mich. : ProQuest Information and Learning Company, [2008]. 1 microfilm reel ; 35 mm. Online version available on the World Wide Web.

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Zhao, Yu. "Reverse osmosis desalination in a mini renewable energy power supply system." Thesis, Curtin University, 2006. http://hdl.handle.net/20.500.11937/2099.

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The design, construction and testing of a reverse-osmosis (PV-RO) desalination system for fresh water shortage area is presented. The system operates from salt water or brackish water and can be embedded in a renewable energy power supply system, since many fresh shortage areas are remote and isolated. Special attention is given to the energy efficiency of small-scale reverse osmosis desalination systems. Limitations of conventional control strategy using toggle control are presented. Based on this, an objective of creating a small-scale reverse osmosis desalination system was set out. Initially, the background information is presented. This includes the natural resources crisis and main desalination technologies and the viability of the integration with renewable energy source. A reverse osmosis (RO) desalination system was assembled and set up at the Curtin University of Technology, Perth, Western Australia Supervisor Control And Data Acquisition (SCADA) system was built using a Human Machine Interface software and a programmable logic controller (PLC). Instrumentation that included signal conditioners was made in analysis of the system characteristics. Initial testing of the system was conducted after the system design and configuration was accomplished. Testing results were used as a guideline for the development of the whole system.Modelling and simulation of the system components in MATLABSimulink is presented, together with a discussion of the control systems modelling and design procedure, in which the aim was to improve the efficiency of the reverse osmosis system. Simulations show the designed reverse osmosis system with Proportional Integral and Derivative (PID) controller has better performance than other controllers. This consequently leads to a lower overall cost of the water, as well as reducing full maintenance cost of the electric drives in the reverse osmosis unit. Additionally, the configuration of the remote control system through General Package Radio System (GPRS) network is depicted. After the PID control algorithm was programmed into the Programmable Logic Controller (PLC), system experiments were carried out in short durations and long durations. System performance was monitored and experimental results prove that the new control strategy applied increase the water productivity and is able to improve the system efficiency up to 35%. Based on the data obtained from the simulations and experiments, Mundoo Island was chosen to be the location for a case study. The electric load profile of the island was derived from the Island Development Committee in Mundoo.A water demand profile was created and modelled in Matlab to be the input of the reverse osmosis system. The electric load of the reverse osmosis system was generated from Matlab simulation. This result was entered in Hybrid Optimisation Model for Electric Renewables (HOMER) simulator. Having the designed RO unit as one of the electric loads, the entire remote area power supply (RAPS) system was tested in simulations which shows the energy cost is AUS$0.174 per kWh, lower than the Island Development Committee budget estimation of AUS$0.25 per kWh. The cost of the water treatment is very promising at AUS$0.77 per m3.

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Zhao, Yu. "Reverse osmosis desalination in a mini renewable energy power supply system." Curtin University of Technology, Dept. of Electrical and Computer Engineering, 2006. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=18552.

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The design, construction and testing of a reverse-osmosis (PV-RO) desalination system for fresh water shortage area is presented. The system operates from salt water or brackish water and can be embedded in a renewable energy power supply system, since many fresh shortage areas are remote and isolated. Special attention is given to the energy efficiency of small-scale reverse osmosis desalination systems. Limitations of conventional control strategy using toggle control are presented. Based on this, an objective of creating a small-scale reverse osmosis desalination system was set out. Initially, the background information is presented. This includes the natural resources crisis and main desalination technologies and the viability of the integration with renewable energy source. A reverse osmosis (RO) desalination system was assembled and set up at the Curtin University of Technology, Perth, Western Australia Supervisor Control And Data Acquisition (SCADA) system was built using a Human Machine Interface software and a programmable logic controller (PLC). Instrumentation that included signal conditioners was made in analysis of the system characteristics. Initial testing of the system was conducted after the system design and configuration was accomplished. Testing results were used as a guideline for the development of the whole system.
Modelling and simulation of the system components in MATLABSimulink is presented, together with a discussion of the control systems modelling and design procedure, in which the aim was to improve the efficiency of the reverse osmosis system. Simulations show the designed reverse osmosis system with Proportional Integral and Derivative (PID) controller has better performance than other controllers. This consequently leads to a lower overall cost of the water, as well as reducing full maintenance cost of the electric drives in the reverse osmosis unit. Additionally, the configuration of the remote control system through General Package Radio System (GPRS) network is depicted. After the PID control algorithm was programmed into the Programmable Logic Controller (PLC), system experiments were carried out in short durations and long durations. System performance was monitored and experimental results prove that the new control strategy applied increase the water productivity and is able to improve the system efficiency up to 35%. Based on the data obtained from the simulations and experiments, Mundoo Island was chosen to be the location for a case study. The electric load profile of the island was derived from the Island Development Committee in Mundoo.
A water demand profile was created and modelled in Matlab to be the input of the reverse osmosis system. The electric load of the reverse osmosis system was generated from Matlab simulation. This result was entered in Hybrid Optimisation Model for Electric Renewables (HOMER) simulator. Having the designed RO unit as one of the electric loads, the entire remote area power supply (RAPS) system was tested in simulations which shows the energy cost is AUS$0.174 per kWh, lower than the Island Development Committee budget estimation of AUS$0.25 per kWh. The cost of the water treatment is very promising at AUS$0.77 per m3.

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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
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
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 estÃ 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 Ã 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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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 (ksÃ‚Â»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.

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De, Paz Rowel. "On-farm desalination: Halophyte and evaporation pond for reverse osmosis brine disposal." Thesis, De Paz, Rowel (2019) On-farm desalination: Halophyte and evaporation pond for reverse osmosis brine disposal. Honours thesis, Murdoch University, 2019. https://researchrepository.murdoch.edu.au/id/eprint/54845/.

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Management of brine/reject from reverse osmosis (RO) systems has always been a major concern among the engineering and scientific community. The brine disposal of the RO in the arid region was the main concern in this thesis. The small scale RO plants, located inland need to work out different methods of a brine disposal. The most common method to disposal brine on a small scale inland desalination plants is with evaporation ponds. But, the evaporation pond can be expensive and land-intensive. This thesis considering the potential way to minimize the area requirements of evaporation ponds by proposing a halophyte wetland upstream of an evaporation pond. Since halophyte can survive into the salty water, the brine from the RO unit can be fed into the wetland which would reduce the flow into the evaporation pond, consequently reducing the evaporation pond area. An on-farm, solar-powered, small scale (500 L/hour) brackish water RO unit was set up at the Muresk Institute, Northam. The halophyte wetland was designed to reduce evaporation pond area requirements. A previously detailed evaporation pond design model was used to model the evaporation pond based on the outflow from the halophyte wetland. The evaporation pond reduced the size land area from 626 m2 to 353 m2 and saved 273 m2 of land area. The halophyte wetland has reduction area benefits for the evaporation pond. The halophyte wetland was modeled for 431 m2 land area for all seasons and fit to plant 86 old man saltbush (Atriplex nummularia). The evaporation pond with halophyte wetland has the potential to give an extra source of income to the farmers. The seeds of the old man saltbush were used for food sources of aboriginal people and the plant used for livestock grazing. The salt harvesting in the evaporation pond estimated 10 t of salt in every summer season for industrial purposes.

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17

Roy, Choudhury Shreya. "Synthesis, Characterization and Structure - Property Relationships of Post - sulfonated Poly(arylene ether sulfone) Membranes for Water Desalination." Diss., Virginia Tech, 2019. http://hdl.handle.net/10919/99381.

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Clean water is critical to the safety, security and survivability of humankind. Nearly 41% of the Earth's population lives in water-stressed areas, and water scarcity will be exacerbated by an increasing population. Over 96% of the total water is saline and only 0.8% is accessible fresh water. Thus, saltwater desalination has emerged as the key to tackle the problem of water scarcity. Our current work deals with the membrane process of reverse osmosis. Sulfonated polysulfones are a potential alternative to state-of-the-art thin film polyamides. Synthesized by step growth polymerization, polysulfone membranes have smooth surfaces and they are more chemically resistant relative to polyamides. Previously studied sulfonated polysulfone membranes were synthesized by direct copolymerization of pre-disulfonated comonomer and the sulfonate ions were placed on adjacent rings of bisphenol moiety. This study focuses on placing the sulfonate ions differently along the polysulfone backbone on isolated rings of hydroquinone moiety, and on adjacent rings of biphenol moiety- and its effect on the transport and hydrated mechanical properties of the membranes. Selective post sulfonation of poly(arylene ether sulfone) in mild conditions was also found to be an effective way to strategically place the sulfonate ions along the backbone of the polymer chain without the need to synthesize a new monomer. Hydroquinone based, amine terminated oligomers were synthesized with block molecular weights of 5000 and 10,000 g/mol. They were post-sulfonated and crosslinked at their termini with epoxy reagents. Such crosslinked and linear membranes had sulfonate ions on isolated rings of hydroquinone moiety. Synthesis and kinetics of controlled post-sulfonation of poly(arylene ether sulfones) that contained biphenol units were also reported. The sulfonation reaction proceeded only on the biphenol rings. The linear membranes had sulfonate ions on adjacent rings of biphenol moieties. The tensile measurements were performed on the membranes under fully hydrated conditions. All membranes remained glassy at values of water uptake. It was found that elastic moduli and yield strengths in the hydroquinone- based linear and crosslinked membranes increased with decrease in water uptakes in the membranes. The effect of plasticization of water superseded the effect of block length and degree of sulfonation in the membranes. The highest elastic modulus of 1420 MPa at lowest water uptake of 18% was observed in cross linked membrane with 50% repeat units being sulfonated (50% repeat units contain hydroquinone)and target molecular weight of 5000 g/mol. However, the hydroquinone membranes broke at low strains of < 20%. The hydrated mechanical properties could be improved by replacing the hydroquinone with biphenol moieties. The biphenol based post-sulfonated membrane showed high elastic modulus that was comparable to the hydroquinone-based counterparts at similar values of water uptake. The biphenol based membrane broke at higher strains of >80%. The post-sulfonated membranes- hydroquinone-based linear and crosslinked membranes and biphenol-based linear membranes had better transport properties than the previously studied sulfonated polysulfones that were synthesized by disulfonated comonomers.The post sulfonated hydroquinone-based membranes did not show a compromise in the rejection of monovalent ions in the presence of divalent ions in mixed feed water. The superior properties of the post-sulfonated membranes can potentially be attributed to the kinked backbone that potentially increased the free volume in the membranes and the sulfonate ions were spaced apart to potentially reduce their chelation with calcium (divalent) ions in mixed feed water. Interestingly, the biphenol based post-sulfonated membranes also did not have any compromise in the rejection of monovalent ions in the presence of divalent ions. This was potentially because the sulfonate ions were spaced far apart on the non-planar biphenol rings.
PHD

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18

Kitley, David. "Exploring renewable energy powered reverse osmosis desalination plants in South Africa: a costing analysis of Reverse Osmosis desalination plants powered by renewable energy and their potential for South Africa." Master's thesis, University of Cape Town, 2011. http://hdl.handle.net/11427/11678.

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The desalination process requires large amounts of energy, either in the form of waste heat or grid electricity. If conventional grid electricity sources are used to power desalination plants, the burning of fossil fuels will contribute towards the release of greenhouse gasses.

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19

Faze, Natasha Ranjit. "Life Cycle And Economic Analysis Comparing Microbial Desalination Cell And Reverse Osmosis Technologies." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1428934798.

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20

Corral, Andrea F. "Alternative Technologies for Inland Desalination." Diss., The University of Arizona, 2014. http://hdl.handle.net/10150/333122.

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Water scarcity is one of the biggest issues we have to face as population and water consumption levels increase despite a fixed supply of renewable fresh water. Meeting the challenges that water scarcity poses to food production, ecosystem health, and political and social stability will require new approaches to using and managing water. Desalination already plays an essential role in water management. It constitutes a secure source of safe drinking water supply once demand management measures are fully implemented. Overcoming problems related to brine minimization and disposal is key to sustainable, efficient inland water desalination. The main focus of this was the investigation of technical limits and improvements for application in inland desalination. The first part of the dissertation covers the study of Membrane Distillation (MD) for desalination of water. The second part provides a broad perspective of Reverse Osmosis (RO), pretreatments -comparison of slow sand filtration and microfiltration-, post-mortem study of membranes to determining fouling and scaling causes, and RO brine minimization via Vibratory Shear Enhance Processing (VSEP®) for use in RO brine minimization. The study of Vacuum Membrane Distillation in a hollow fiber membrane was studied. Experimental work is supported by an original mathematical model to expose the physics of VMD and support predictions that extend VMD results beyond these generated in the laboratory. The advantages and disadvantages of each pretreatment, including their effects the effect on the performance of RO, a post-mortem membrane study and an economic analysis. The post-mortem study of membranes used during Yuma Desalting Plant operation. This work was used to identify the best pretreatment and more suitable membrane to treat saline water in the lower Colorado River. The work performed during the brine minimization study using VSEP®. This study included experimental data and an extensive economic analysis comparing Ion Exchange (IX) as pretreatment and VSEP® as post-treatment for RO.

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21

Yenal, Umur. "MAXIMIZING WATER RECOVERY DURING REVERSE OSMOSIS (RO) TREATMENT OF CENTRAL ARIZONA PROJECT (CAP) WATER." Diss., The University of Arizona, 2009. http://hdl.handle.net/10150/195247.

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Central Arizona Project water was treated using slow sand filtration (SSF) and reverse osmosis (RO) in series. Additional desalination water was recovered from RO brine using the vibratory shear-enhanced processing (VSEPÂ®; New Logic, Inc.). SSF removed 90% of the turbidity in raw CAP water. SSF decreased total organic carbon by almost 20%. After a little more than a year of continuous operation, performance of the RO system declined noticeably, as indicated by a rapid decrease in membrane permeation coefficient and an increase in salt flux. Foulant scrapings contained both clay material and large amounts of unidentified organics. Alternative hypotheses regarding major sources of membrane foulants are discussed in this study.Water lost as brine was reduced from 20% to 2-4% via post-RO VSEP treatment. Estimated costs were compared to those of a no-VSEP option in which disposal of the entire RO brine flow was required. The total annualized cost of brine treatment was fairly insensitive to recovery during VSEP treatment in the range 80-90%, and the period of VSEP operation between cleanings in the range 25-40 hrs. These values define a fairly broad window for near optimal VSEP operation under the conditions of the study. The cost of VSEP treatment to minimize brine loss was estimated at $394- $430 per acre foot ($1.21 - $1.32 per 1000 gal) of 15 MGD CAP water treated. For a hypothetical 3 MGD RO brine flow, the use of VSEP to recover water and reduce the volume of brine for disposal results in a savings of more than $5M/year relative to the no-VSEP brine disposal alternative.

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22

Soliz, Deserié H. "Production of the Forage Halophyte Atriplex lentiformis on Reverse Osmosis Brine." Diss., The University of Arizona, 2011. http://hdl.handle.net/10150/202737.

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Throughout the arid and semi-arid regions, researchers have been looking at different ways to deal with the salinity problem of the soil and water as well as feed for the livestock. Study 1 focused on a pilot project conducted in an irrigation district in Marana, AZ, USA, looking at using Reverse Osmosis (RO) concentrate on Atriplex lentiformis (quailbush) and then harvesting the plant to be tested for its possible use as a supplement in feed for livestock. Three irrigation treatments were tested based on the potential evapotranspiration rate (ET(o)): (1) plots irrigated at ET(o) adjusted daily via an on-site micrometeorology station; (2) plots irrigated at 1.5 ET(o) adjusted daily; (3) plots irrigated at a constant rate throughout the year based on the mean of annual ET(o). The plants produced 15-24 tons ha⁻¹ year⁻¹ of biomass and could be irrigated at the rate of ET(o), ca. 2 m yr⁻¹ at this location. It was concluded that irrigation of halophyte forage crops provide a viable strategy for extending water supplies and disposing of saline water in arid-zone irrigation districts. Study 2 focused on a field data from Study 1 and two greenhouse experiments. The greenhouse experiments were conducted in 2007 and 2010. The 2010 greenhouse trials, under well-watered conditions, showed that the apparent zero-point-salinity for yield was 47.3 g L⁻¹ TDS. An additional greenhouse experiment was conducted in which plants in sealed pots were grown to the wilting point on a single application of water. The experiment was conducted at different salinities to see if salinity and water stress were additive factors in reducing yield and Water Use Efficiency (WUE). To the contrary, yield and WUE actually increased as a function of salinity, perhaps due to conversion from C3 to C4 photosynthesis over the salinity range (noted in other studies with A. lentiformis). We conclude that xerohalophytes such as A. lentiformis could greatly extend the useful range of salinities under which forage crops can be grown in arid-zone irrigation districts.

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23

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%.
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.

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24

Zhao, Lin. "Advanced Reverse Osmosis Membranes for Desalination and Inorganic/Polymer Composite Membranes for CO2 Capture." The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1405729817.

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25

Nasir, Subriyer. "Membrane performance and build-up of solute during small scale reverse osmosis operation." Thesis, Curtin University, 2007. http://hdl.handle.net/20.500.11937/590.

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Reverse Osmosis (RO) is widely accepted as an alternative method to produce freshwater from different feed water sources. This technology competitively substitutes the thermal processes in the near future because of several advantages particularly in energy saving. The success of RO operation will, however, depends largely on the overall membrane performance. Deposit or build-up of solute is one of the main reasons for membrane operation failure. Build-up of solute or deposit which is known as fouling and scaling will decrease the permeate flux and increase the energy consumption in particular after prolonged operation of RO. The thesis presents the experimental results obtained in a small-scale RO system. The aim of this study is to investigate the effect of sodium chloride and calcium carbonate on the membrane performance and subsequent build-up of solute on the membrane surface. The experiments were carried out in a small-scale of RO (2 m3/day capacity) with spiral wound membrane using simulated feed water, secondary effluent, and groundwater samples. The parameters chosen for the experiments are applied pressure (1250-4750 kPa), and concentration of sodium chloride (l00-5000 mg/L) and calcium carbonate (50-100 mg/L).The results from feedwater runs indicated that initial sodium chloride and calcium carbonate in feed water and applied pressure affects the overall membrane performance. However, there is no significant effect on membrane performance for sodium chloride with concentration below 1200 mg/L and applied pressure lower than 2250 kPa. Applied pressure appears to have an impact on build-up of sodium and calcium on the membrane surface for pressures greater than 2750 kPa. For typical small-scale RO system used in this experiment, build-up of calcium will slightly decrease with given pressure caused by the characteristic of membrane that easily removes the divalent ions. The osmotic pressure of solution also strongly affects the permeate flow rate in particular for relatively higher sodium concentration (> 2500 mg/L). As a consequence of higher osmotic pressure, zero permeate flux is achieved when sodium chloride concentration was greater than 5000 mg/L and applied pressure lower than 1750 kPa. Results also indicated that fouling might pose a potential problem in small-scale RO operation. In order to investigate the membrane performance, experiments with secondary effluent samples were also performed. Results indicated that water recovery percentages and permeate flux also linearly increase with applied pressure. However, effectiveness of membrane decreases less than 98% otherwise build-up of solute tends to increase. It is suggested that lower values of the water recovery percentage (WRP) and permeate flux (Jw) are caused by the characteristic of secondary effluent that have high-suspended solids, organic carbon, and minerals. Further, the membrane performance also examined with ground water as feed water sample.Results showed that both water recovery percentage and permeate flux linearly increased with operating pressure. However, intensive pretreatment are required as a result of higher concentration of humic acid and iron in raw feed. Percentages of ion rejection for sodium and calcium are greater than 98 and 99% respectively. The high ion rejections are mainly due to the characteristics of groundwater with low TDS and EC. Sodium and calcium build-up in a small-scale RO system considered appears to be affected by the applied pressure. Build-up of solute in small-scale of RO system has been predicted using the empirical model proposed in this work. Two ions namely sodium and calcium in feed water considered as predominant ions responsible for fouling and scaling on the membrane surface. Four main parameters namely, applied pressure (P), permeate flux (Jw), membrane resistance (Rm), and feed concentration (Cf) are considered which strongly affect the overall membrane performance. The empirical correlations derived from experimental observation among these parameters can be expressed as follows: In Md NaCI = O. 77 In P + 0.67 In Jw + 0.19 In Rm + 0.171n Cf In Md CaCO3= 0.96 In P + 0.75 In Jw + 0.2 In Rm - 0.07 In CfThe empirical models proposed in this thesis may be useful for predicting the buildup of solute on the membrane surfaces. In the present work, an attempt has been made to estimate the energy consumption and unit cost for desalting of different feed water samples in a small-scale RO system. In RO plants, unit cost of water production from feed water is primarily governed by the energy required for pumping raw water. Estimates of specific energy consumption (SEC) for desalting of sodium chloride, combined sodium and calcium carbonate solutions were found to be in the range of 0.79 - 3.21 and 0.81 - 3.22 kwh/m3 respectively. For groundwater and secondary effluent, they are estimated to 0.63 - 1.71 and 0.79 - 2.02 kWh/m3 respectively. Moreover, energy consumption for different feed water samples was used to estimate the unit cost for water production. Estimation of unit costs for combined sodium chloride and calcium carbonate solution, groundwater, and secondary effluent runs are $2.06 - 3.22, $1.98 - 2.57 and $1.56- 2.66 respectively. In this work, unit cost is still higher due to greater energy consumption .by the pumping system which is required in a small-scale RO operation. Based on the experimental results, it appears that the characteristics of feed water samples affect the membrane performance and their effects must be taken into account in the design of RO units so as to reduce the unit cost for water production.The findings from the present experimental and modelling work are of practical significance in not only providing the knowledge base in the area of desalination but also paves the way for developing tools for the prediction of build-up of solutes on membrane surface in full scale reverse osmosis operations.

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26

Jayasekara, Buddhika. "ASSESSMENT OF DESALINATION NEEDS AND APPROPRIATE TECHNOLGIES FOR SRI LANKA." Thesis, Högskolan i Gävle, Avdelningen för bygg- energi- och miljöteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-24734.

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This study investigates the desalination needs and available technologies in Sri Lanka. Lack of rainfall, pollution due to agricultural chemicals, presence of fluoride, increasing demand, exploitation of ground water and brackishness have created scarcity of fresh pure water specially in near costal and dry zones in Sri Lanka. Due to Cronic Kidney Disease (CKD) around 500 people died in dry zones annually which is suspected to cause by Arsenic and Cadmium contain in ground water due to agriculture chemicals. The available desalination methods are Reverse Osmosis (RO), Solar distillation and conventional methods. The cost for RO is Rs.0.10 cents per liter and solar distillation Rs.2.96 per liter. Although the price shows that the RO is better but due to high initial investment as a third world country it is very difficult to afford huge initial investment without government intervention. The experimental solar desalination units only produce nearly 5liters of potable water per day and directly impacted by availability of solar radiation. The energy availability of Sri Lanka and future potable water demand predicted as 2188.3 Mn liters as maximum demand which will be in 2030, therefore by that time the government should have a proper plan to cater the demand and desalination plants need to be planned and built based on the demand of dry zones and specially agriculture areas. The applicability of renewable energy for desalination in local arena was also simulated taking the Delf Reverse Osmosis plant for the simulation. Results show that the optimum design is combination of Solar PV and existing 100kW Diesel generator Set with Battery bank and converter.

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27

Fernandes, Ângela Soares Ramos. "Adequabilidade da energia solar para a produção autónoma de água dessalinizada." Master's thesis, ISA, 2013. http://hdl.handle.net/10400.5/6482.

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Mestrado em Engenharia do Ambiente - Instituto Superior de Agronomia
The issue of water scarcity has been felt with more intensity in the arid and semi-arid regions. These regions are characterized by climate variability and recurrent droughts, affecting the socio-economic development of these areas. In remote areas with limited water resources, desalination is used as a primary source for drinking water supplies to communities. Between the various technologies available in desalination, inverse osmosis is the most used technology for drinking water production. Photovoltaic solar energy solves the issue of electrification in rural areas, becoming an added value since it allows achieve energetic autonomy for the conventional system. This paper aims to assess the potential of decentralized desalination using solar energy applied to small scale. To study the applicability and viability of the technology is realized pre-sizing of the reverse osmosis system associated with the photovoltaic system to be installed in a rural area in Cabo-Verde. The validation of this combination of technologies and their implementation at the site requires the guarantee of sustainable development for communities. The obtained results show the viability of drinking water autonomous production which ensures the needs of population.

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28

Eriksson, Olof. "Techno Economic Analysis of Reverse Osmosis Combined with CSP + PV in Kuwait." Thesis, Högskolan Dalarna, Energiteknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:du-34521.

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Seawater desalination plays an important role when fighting the freshwater scarcity that many places around the world are currently facing. The increasing need for desalinated water is followed by a high energy demand. It is therefore essential that an expansion of desalination capacity is accompanied by a parallel use of renewable energy sources in this process. This thesis presents a techno-economic study on a reverse osmosis (RO) desalination plant, with a nominal power consumption of 15 MW, that is powered by a concentrated solar power (CSP) plant combined with a photovoltaic (PV) power plant, in Kuwait. The main aim of this thesis was to find which system designs would give the lowest global warming potential and levelized cost of the desalinated water. In addition, it has been investigated how electricity price and emission allowance cost could make a solar power plant competitive to the grid. For this purpose, some components in the whole system were simulated using System Advisor Model and Engineering Equation Solver. With the results obtained from the simulations, a dynamic model of the whole system was developed in MATLAB, Simulink where simulations were done for a typical meteorological year in Shagaya, Kuwait. Both on-grid and off-grid systems were considered. In the on-grid case, the lowest cost of water was obtained with only PV (ca 0.65 USD/m3) and this could reduce carbon emissions by 30 % compared to only using the grid. Combining CSP and PV could reduce the carbon emissions by 85 % but with a 35 % increase in water cost. It was found that an electricity price of 0.1 USD/kWh or an emission allowance cost of 70 USD/tCO2-eq would make a CSP + PV plant competitive to the grid. These results indicate that the choice of which system is best for powering an on-grid RO plant depends on how the environmental and economic factors are prioritised. In the case of the off-grid system, both the lowest cost of water (ca 0.9 USD/m3) and the highest capacity factor were obtained with a CSP + PV plant with 16 h of storage, a solar multiple of 3 and a PV capacity of 28 MW.

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29

Nasir, Subriyer. "Membrane performance and build-up of solute during small scale reverse osmosis operation." Curtin University of Technology, Department of Chemical Engineering, 2007. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=17394.

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Reverse Osmosis (RO) is widely accepted as an alternative method to produce freshwater from different feed water sources. This technology competitively substitutes the thermal processes in the near future because of several advantages particularly in energy saving. The success of RO operation will, however, depends largely on the overall membrane performance. Deposit or build-up of solute is one of the main reasons for membrane operation failure. Build-up of solute or deposit which is known as fouling and scaling will decrease the permeate flux and increase the energy consumption in particular after prolonged operation of RO. The thesis presents the experimental results obtained in a small-scale RO system. The aim of this study is to investigate the effect of sodium chloride and calcium carbonate on the membrane performance and subsequent build-up of solute on the membrane surface. The experiments were carried out in a small-scale of RO (2 m3/day capacity) with spiral wound membrane using simulated feed water, secondary effluent, and groundwater samples. The parameters chosen for the experiments are applied pressure (1250-4750 kPa), and concentration of sodium chloride (l00-5000 mg/L) and calcium carbonate (50-100 mg/L).
The results from feedwater runs indicated that initial sodium chloride and calcium carbonate in feed water and applied pressure affects the overall membrane performance. However, there is no significant effect on membrane performance for sodium chloride with concentration below 1200 mg/L and applied pressure lower than 2250 kPa. Applied pressure appears to have an impact on build-up of sodium and calcium on the membrane surface for pressures greater than 2750 kPa. For typical small-scale RO system used in this experiment, build-up of calcium will slightly decrease with given pressure caused by the characteristic of membrane that easily removes the divalent ions. The osmotic pressure of solution also strongly affects the permeate flow rate in particular for relatively higher sodium concentration (> 2500 mg/L). As a consequence of higher osmotic pressure, zero permeate flux is achieved when sodium chloride concentration was greater than 5000 mg/L and applied pressure lower than 1750 kPa. Results also indicated that fouling might pose a potential problem in small-scale RO operation. In order to investigate the membrane performance, experiments with secondary effluent samples were also performed. Results indicated that water recovery percentages and permeate flux also linearly increase with applied pressure. However, effectiveness of membrane decreases less than 98% otherwise build-up of solute tends to increase. It is suggested that lower values of the water recovery percentage (WRP) and permeate flux (Jw) are caused by the characteristic of secondary effluent that have high-suspended solids, organic carbon, and minerals. Further, the membrane performance also examined with ground water as feed water sample.
Results showed that both water recovery percentage and permeate flux linearly increased with operating pressure. However, intensive pretreatment are required as a result of higher concentration of humic acid and iron in raw feed. Percentages of ion rejection for sodium and calcium are greater than 98 and 99% respectively. The high ion rejections are mainly due to the characteristics of groundwater with low TDS and EC. Sodium and calcium build-up in a small-scale RO system considered appears to be affected by the applied pressure. Build-up of solute in small-scale of RO system has been predicted using the empirical model proposed in this work. Two ions namely sodium and calcium in feed water considered as predominant ions responsible for fouling and scaling on the membrane surface. Four main parameters namely, applied pressure (P), permeate flux (Jw), membrane resistance (Rm), and feed concentration (Cf) are considered which strongly affect the overall membrane performance. The empirical correlations derived from experimental observation among these parameters can be expressed as follows: In Md NaCI = O. 77 In P + 0.67 In Jw + 0.19 In Rm + 0.171n Cf In Md CaCO3= 0.96 In P + 0.75 In Jw + 0.2 In Rm - 0.07 In Cf
The empirical models proposed in this thesis may be useful for predicting the buildup of solute on the membrane surfaces. In the present work, an attempt has been made to estimate the energy consumption and unit cost for desalting of different feed water samples in a small-scale RO system. In RO plants, unit cost of water production from feed water is primarily governed by the energy required for pumping raw water. Estimates of specific energy consumption (SEC) for desalting of sodium chloride, combined sodium and calcium carbonate solutions were found to be in the range of 0.79 - 3.21 and 0.81 - 3.22 kwh/m3 respectively. For groundwater and secondary effluent, they are estimated to 0.63 - 1.71 and 0.79 - 2.02 kWh/m3 respectively. Moreover, energy consumption for different feed water samples was used to estimate the unit cost for water production. Estimation of unit costs for combined sodium chloride and calcium carbonate solution, groundwater, and secondary effluent runs are $2.06 - 3.22, $1.98 - 2.57 and $1.56- 2.66 respectively. In this work, unit cost is still higher due to greater energy consumption .by the pumping system which is required in a small-scale RO operation. Based on the experimental results, it appears that the characteristics of feed water samples affect the membrane performance and their effects must be taken into account in the design of RO units so as to reduce the unit cost for water production.
The findings from the present experimental and modelling work are of practical significance in not only providing the knowledge base in the area of desalination but also paves the way for developing tools for the prediction of build-up of solutes on membrane surface in full scale reverse osmosis operations.

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30

Clarke, Daniel. "Stand-alone solar-pv hydrogen energy systems incorporating reverse osmosis." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2015. https://ro.ecu.edu.au/theses/1750.

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The world’s increasing energy demand means the rate at which fossil fuels are consumed has increased resulting in greater carbon dioxide emissions. For many small (marginalised) or coastal communities, access to potable water is limited alongside good availability of renewable energy sources (solar or wind). One solution is to utilise small-scale renewably powered stand-alone energy systems to help supply power for everyday utilities and to operate desalination systems serving potable water (drinking) needs reducing diesel generator dependence. In such systems, on-site water production is essential so as to service electrolysis for hydrogen generation for Proton Exchange Membrane (PEM) fuel cells. Whilst small Reverse Osmosis (RO) units may function as a (useful) dump load, it also directly impacts the power management of stand-alone energy systems and affects operational characteristics. However, renewable energy sources are intermittent in nature, thus power generation from renewables may not be adequate to satisfy load demands. Therefore, energy storage and an effective Power Management Strategy (PMS) are vital to ensure system reliability. This thesis utilises a combination of experiments and modelling to analyse the performance of renewably powered stand-alone energy systems consisting of photovoltaic panels, PEM electrolysers, PEM fuel cells, batteries, metal hydrides and Reverse Osmosis (RO) under various scenarios. Laboratory experiments have been done to resolve time-resolved characteristics for these system components and ascertain their impact on system performance. However, the main objective of the study is to ascertain the differences between applying (simplistic) predictive/optimisation techniques compared to intelligent tools in renewable energy systems. This is achieved through applying intelligent tools such as Neural Networks and Particle Swarm Optimisation for different aspects that govern system design and operation as well as solar irradiance prediction. Results indicate the importance of device level transients, temporal resolution of available solar irradiance and type of external load profile (static or time-varying) as system performance is affected differently. In this regard, minute resolved simulations are utilised to account for all component transients including predicting the key input to the system, namely available solar resource which can be affected by various climatic conditions such as rainfall. System behaviour is (generally) more accurately predicted utilising Neural Network solar irradiance prediction compared to the ASHRAE clear sky model when benchmarked against measured irradiance data. Allowing Particle Swarm Optimisation (PSO) to further adjust specific control set-points within the systems PMS results in improvements in system operational characteristics compared to using simplistic rule-based design methods. In such systems, increasing energy storage capacities generally allow for more renewable energy penetration yet only affect the operational characteristics up to a threshold capacity. Additionally, simultaneously optimising system size and PMS to satisfy a multi-objective function, consisting of total Net Present Cost and CO2 emissions, yielded lower costs and carbon emissions compared to HOMER, a widely adopted sizing software tool. Further development of this thesis will allow further improvements in the development of renewably powered energy systems providing clean, reliable, cost-effective energy. All simulations are performed on a desktop PC having an Intel i3 processor using either MATLAB/Simulink or HOMER.

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Hou, Novalie, and Sofie Jiang. "Concentrator photovoltaics combined with reverse osmosis and membrane distillation for high-efficiency desalination and electricity production." Thesis, KTH, Hållbar utveckling, miljövetenskap och teknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-282908.

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This project is a bachelor thesis and aims to study the integration of concentrator photovoltaics (CPV), reverse osmosis (RO) and membrane distillation (MD) for water desalination and purification. In this report, an introduction of the need for efficient water desalination is presented. Following the introduction, relevant literature has been reviewed to build up the fundamental understanding of CPV, RO and MD. A general classification of CPV subsequently introduced. In order to acquire a more comprehensive understanding of CPVs, two case studies were performed with two different types of CPV/T. The cost efficiency of each type of CPV was analysed when integrated with RO and MD systems. The result turns out to be that it was not economically beneficial to have MD in the integrated system. The reason behind is the extensive thermal energy demand of MD. Other affecting parameters, such as location and system types were also discussed. Lastly, improvements and suggestions for further studies were considered.
Detta projekt är en kandidatuppsats och syftar till att studera ett integrerande system bestående av koncentrerade solceller (CPV), omvänd osmos (RO) och membrandestillation (MD) för vattenavsaltning och rening. Rapporten börjar med en introduktion om behovet av effektiv avsaltning av vatten. Relevant litteratur har granskats för att bygga upp den grundläggande förståelsen för CPV, RO och MD. Därefter gjordes en klassificering av CPV. För att få en mer omfattande förståelse av CPV valdes två olika typer av CPV /T för en djupare undersökning. Kostnadseffektiviteten för varje CPV analyserades, när dessa var integrerade med RO- och MD-system. Resultatet visar sig att det tyvärr inte var ekonomiskt fördelaktigt att ha med MD i det integrerade systemet. Anledningen bakom detta var det omfattande termiska energibehovet för MD. Andra avgörande faktorer, såsom plats och systemtyp diskuterades tillika. Slutligen avslutades rapporten med förslag på förbättringar och områden för vidare studier.

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Rosa, Daniel Jordão de Magalhães. "Sistemas fotovoltaicos domiciliares de dessalinização de água para consumo humano: um estudo de sua viabilidade e configurações." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/86/86131/tde-07032014-161629/.

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Grande parte da população rural do Semiárido brasileiro sofre com problemas de acesso à água de qualidade. A exploração da água subterrânea representa uma das principais alternativas para o abastecimento dessa parcela da população, mas muitas vezes os poços perfurados encontram-se longe da rede elétrica. A região apresenta abundante recurso solar e, assim, essa dificuldade poderia ser contornada com a utilização de sistemas fotovoltaicos de bombeamento. Mas, além da questão da energia para o funcionamento dos sistemas de bombeamento, pelo fato da maior parte do Semiárido estar localizada sobre escudo cristalino, muitos poços apresentam água com altos níveis de salinidade, o que inviabiliza a utilização desses mananciais para o fornecimento de água potável ou faz com que a população rejeite seu consumo, por conta do gosto. O presente trabalho tem como objetivo verificar se a adaptação de sistemas de dessalinização de pequeno porte disponíveis comercialmente a sistemas fotovoltaicos domiciliares pode potencializar a difusão dos sistemas fotovoltaicos de bombeamento em poços de água com alto teor de sais dissolvidos e se essa opção pode representar uma alternativa de fornecimento de água para a população rural de áreas com problemas de salinização dos mananciais de abastecimento. A opção analisada consiste em um sistema duplo de fornecimento de água, com tratamento do tipo ponto de uso da água para consumo humano. Foi verificado que os sistemas de dessalinização atualmente disponíveis no mercado podem funcionar acoplados a geradores fotovoltaicos e utilizados para fornecimento de água potável a partir de água salobra.
Much of the rural population of the Brazilian Semiarid region suffers from problems related to access of improved water quality. The exploitation of ground water is the main alternative for water supply solutions regarding this population, but often the boreholes are away from power lines. The region has abundant solar source and therefore this problem could be overcome with the use of photovoltaic pumping systems. Beyond the issue of energy for operation of the borehole systems, considering that most of the semiarid region is located on crystalline shield, many boreholes have water with high level of salinity, which hinder their use for drinking water supply solutions, as the population rejects the water because of its taste. This study aims to determine whether the adaptation of commercially available small household desalinization systems adapted to photovoltaic systems can enhance the diffusion of photovoltaic pumping systems of boreholes with high concentrations of dissolved salt, by proposing this water supply solution as an alternative for water supply systems in rural areas with problems of salinization of the main water sources. The proposed technical solution consists of a dual water supply system with the use a point of use water treatment for human consumption. It was found that desalination systems available on the market can operate coupled to photovoltaic generators and used to supply drinking water from brackish water.

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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.

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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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Shames, Elhashmi Adel. "An investigation into the effect of different types of antiscalant on desalination reverse osmosis (Ro) membrane flux." Thesis, Cape Peninsula University of Technology, 2012. http://hdl.handle.net/20.500.11838/2609.

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Thesis (MTech (Chemical Engineering))--Cape Peninsula University of Technology, 2012.
Recently much research and development has been done into the creation of desalination systems in South Africa, with particular emphasis on the commercialisation of desalination plants that serve local communities. This has been successful - there are currently plants running at Bitlerfontien, Bushmans River Mouth and Robben Island - although membrane fouling and scaling remains a problem associated with membrane desalination, as it does worldwide The aim of this study was to Investigate the performance of different type of antiscalants on artificially scaled membranes which we prepared inside the lab as well as on scaled membranes which were used in pilot plant. We used two type of anti-sealants in our research: Vitec 3000 and Zinc ions. The effects of these anti-sealants on the membrane were determind and the RO performances of the treated and untreated membrane compared. A suitable autopsy procedure was established and was then used to autopsy the XLE 4040 membranes. The autopsied membranes were characterized by scanning electron microscopy (SEM) and optical microscopy (OM). The SEM and OM results clearly showed that scaling had taken place: deposits were observed for both the shell and core samples, which were not present in the images of the untreated membrane, especially when looking at high SEM images magnification. Results also showed that the anti-sealants reduced the fouling and scaling on the membrane surface. As a result, the membrane rejection improved. Rejection and flux results indicated that commercial anti-sealant was more effective in preventing scaling than the Zinc ions. For Vitec anti-sealant case, the flux was in steady state at 36.8 Imh (5% less) after 5 hours compared to around 35 Imh (8% less) for zinc ions case. In addition; SEM images showed that less deposited particles are formed when the membrane was treated with commercial anti-sealant.

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Reed, Elizabeth Anne S. M. Massachusetts Institute of Technology. "The design of a controllable energy recovery device for solar powered reverse osmosis desalination with experimental validation." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/74940.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2012.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 84-86).
The purpose of this thesis is to design and validate a controllable energy recovery device with application to photovoltaic powered reverse osmosis (PVRO). The energy consumption of a reverse osmosis plant depends significantly on the efficiency of its energy recovery process. This work presents a concept for a controllable energy recovery process, so that a system can operate optimally based on the incoming water and power characteristics. The design presented here uses a variable nozzle and a Pelton wheel to recover energy from the high pressure concentrated brine exiting the reverse osmosis membrane. The components are designed, analytically modeled using fundamental engineering principles, and experimentally tested. The experimental data is then used to check the validity of the formulated concept models. This research encompasses the modeling and testing of a variable nozzle using a needle valve to control the flow through the nozzle, and also of a Pelton bucket, to examine the effectiveness of the momentum transfer from a high velocity jet to the Pelton wheel. This research is done to examine the feasibility of this concept for potential implementation on a full scale PVRO system. The component validation is performed to prove that the concept is effective and competitive with other options.
by Elizabeth Anne Reed.
S.M.

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Qiu, Tianyu. "Desalination of brackish water by a batch reverse osmosis desalink system for use with solar thermal energy." Thesis, Aston University, 2014. http://publications.aston.ac.uk/24333/.

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For remote, semi-arid areas, brackish groundwater (BW) desalination powered by solar energy may serve as the most technically and economically viable means to alleviate the water stresses. For such systems, high recovery ratio is desired because of the technical and economical difficulties of concentrate management. It has been demonstrated that the current, conventional solar reverse osmosis (RO) desalination can be improved by 40–200 times by eliminating unnecessary energy losses. In this work, a batch-RO system that can be powered by a thermal Rankine cycle has been developed. By directly recycling high pressure concentrates and by using a linkage connection to provide increasing feed pressures, the batch-RO has been shown to achieve a 70% saving in energy consumption compared to a continuous single-stage RO system. Theoretical investigations on the mass transfer phenomena, including dispersion and concentration polarization, have been carried out to complement and to guide experimental efforts. The performance evaluation of the batch-RO system, named DesaLink, has been based on extensive experimental tests performed upon it. Operating DesaLink using compressed air as power supply under laboratory conditions, a freshwater production of approximately 300 litres per day was recorded with a concentration of around 350 ppm, whilst the feed water had a concentration range of 2500–4500 ppm; the corresponding linkage efficiency was around 40%. In the computational aspect, simulation models have been developed and validated for each of the subsystems of DesaLink, upon which an integrated model has been realised for the whole system. The models, both the subsystem ones and the integrated one, have been demonstrated to predict accurately the system performance under specific operational conditions. A simulation case study has been performed using the developed model. Simulation results indicate that the system can be expected to achieve a water production of 200 m3 per year by using a widely available evacuated tube solar collector having an area of only 2 m2. This freshwater production would satisfy the drinking water needs of 163 habitants in the Rajasthan region, the area for which the case study was performed.

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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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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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OLIVEIRA, Arleide Ricarte de. "Desempenho de um sistema de dessalinização via osmose inversa usando energia não-convencional, sem a utilização de acumuladores." Universidade Federal de Campina Grande, 2007. http://dspace.sti.ufcg.edu.br:8080/jspui/handle/riufcg/1720.

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Capes
A falta de água potável em algumas localidades do mundo, mais precisamente no semi-árido, é um problema de caráter secular, agravado pela poluição, distribuição irregular e existência de águas subterrâneas de utilização bastante limitada por causa dos altos índices de salinidade. Por outro lado, essas regiões possuem um grande potencial de irradiação solar que favorece a utilização de painéis fotovoltaicos, principalmente em locais distante da rede elétrica. Visando melhorar a qualidade de vida e minimizar o problema da falta de água potável nessas regiões, esse trabalho tem como objetivo estudar o desempenho de um protótipo de equipamento para fins de dessalinizar águas salobras via osmose inversa, fazendo uso de um gerador fotovoltaico com a utilização de um circuito eletrônico, no qual substitui acumuladores de carga (baterias). Com o uso do circuito eletrônico foi possível produzir água potável sem a necessidade da utilização de acumuladores de carga (baterias) e sem danificar o motor-bomba. A ausência do banco de baterias proporciona uma redução dos custos e da necessidade de manutenção; mas o sistema torna-se subordinado às condições instantâneas da radiação solar e da temperatura ambiente. Esse sistema foi instalado no Laboratório de Referência em Dessalinização (LABDES), na Universidade Federal de Campina Grande. O desempenho do sistema foi avaliado com soluções de cloreto de sódio com concentração de 1.000 mg/L e 2.500 mg/L e água de poço com concentração de 3.800 mg/L. As variáveis de medidas, como: tensão, corrente, vazão e pressão foram obtidas em tempo real no Software Data Aquisition, através de sensores elétricos. A partir desses dados foram avaliados os seguintes parâmetros: potência elétrica, vazão do permeado e do concentrado, recuperação e consumo de energia por m3 de água produzida. As condições meteorológicas e as concentrações da água de alimentação influenciam diretamente na pressão, e consequentemente na produção de água. Mesmo com a grande variação de tensão em função da irradiação solar, o sistema mostrou condições técnicas de produzir 0,25 m3/h de água dessalinizada. A pressão máxima obtida foi de 8,2 kgf/cm2. O balanço econômico, que representa o custo-benefício de implantação, operacional e manutenção para atender comunidades isoladas, mostrou que o menor custo de água dessalinizada é obtido quando o sistema de dessalinização é instalado em localidade na qual já possui o poço tubular e um local para servir de abrigo para o sistema de dessalinização. Para essas localidades é viável o uso de painéis fotovoltaicos.
The lack of drinking water in some places of the world, more precisely in the semi-arid region of Brazil, is an old problem, worsened by the pollution, irregular distribution and high salinity of underground waters. On the other hand, those areas possess a great solar irradiation rate that favors the use of photovoltaic panels, mainly where the electric net is not available. Seeking to improve the life quality and to minimize the problem of the lack of drinking water in those areas, the objective of this work is to study and evaluate an osmosis reverse desalination system, using photovoltaic solar energy coupled to an electronic circuit. This electronic circuit replaces the use of batteries without damaging the motor-bomb. The absence of batteries provides a reduction of the cost and maintenance need; but the system is subordinated to the instantaneous conditions of the solar radiation. This system was installed at the Reference Laboratory of Desalination (LABDES) in the Federal University of Campina Grande. The system was evaluated with sodium chloride solutions of 1,000 and 2,500 mg/L NaCl concentrations, and a well water of 3,800 mg/L TDS concentration. The meteorological conditions and the concentrations of the feeding water influence directly the applied pressure and consequently the permeate production. Even with the intermittent energy delivered by the solar photovoltaic panels, the desalination system showed good technical conditions to produce 0.25 m3/h of potable water. The economical statements , that the implantation cost-benefit represents, operational and maintenance to take care of isolated communities, showed that the lesser desalinizaded water cost is gotten when the desalination system is installed in locality in which already possesss the well and a place to serve of shelter for the desalination system. For these localities the use of photovoltaics panels is viable.

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Seo, Joseph. "SURFACE MODIFICATIONS OF REVERSE OSMOSIS MEMBRANES FOR REMOVAL OF BROMIDE AND REDUCTION OF FOULING." DigitalCommons@CalPoly, 2020. https://digitalcommons.calpoly.edu/theses/2169.

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Reverse osmosis (RO) is widely used for water reuse and desalination. Although RO membranes are known for their high salt rejection and practical permeate flux, their performance can be impaired by fouling, and their removal of some disinfection byproducts and their precursors (e.g., bromide, N-Nitrosodimethylamine [NDMA]) does not meet drinking water standards. RO membrane modifications have been widely studied to overcome these limitations. In this research, RO membranes were grafted with cationic polymers to induce a positive charge on the RO membrane surface. This modification aimed at enhancing the rejection of negatively charged bromide ions by removing them from solution by binding them to the membrane surface. The results showed that the modified (positively charged) RO membranes achieved lower rejection (82% rejection) for bromide ions compared to the unmodified ones (94.5% rejection). This behavior was likely a result of increased concentration polarization of the bromide ions at the membrane surface and/or increase in porosity of the modified membranes. Calculations based on the film theory indicate that the concentration of bromide ions at the surface of the modified membrane was 1371 ppm compared to 1307 ppm at the surface of the unmodified membrane. Evidently, the polymer attraction energy was not sufficient to keep the bromide ions attached to the membrane surface and prevent their diffusion across the membrane. Although the goal of the modification in the current study (i.e., enhancing removal of bromide ions) was not met, the permeate flux of the modified membrane was improved compared to the unmodified one. The literature suggests that increasing flux after modification is likely a result of increase in membrane pore size and hydrophilicity. In addition to the experimental work conducted in this study, a multi-criteria decision analysis was performed to prioritize research on surface modifications of reverse osmosis membranes. It was found that surface modifications have been mainly focused on reducing membrane fouling and to a much lower extent on removal of disinfection byproducts and their precursors. The RO membrane modification alternatives for fouling reduction and N-Nitrosodimethylamine (NDMA) removal were ranked based on multiple criteria using the Analytical Hierarchy Process (AHP) and the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS). This multi-criteria decision analysis process resulted in the identification of the top five promising modifications to reduce fouling and improve NDMA rejection. Grafting and coating the RO membranes with complex polymeric salts were the highest ranked modification approaches to reduce fouling. Heat-treatment of RO membranes achieved the highest NDMA rejection (98%); however, this technique was the second highest ranked modification approach for NDMA removal because it scored lower for other evaluation criteria.

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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/.

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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.
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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Benecke, Jan [Verfasser], and Mathias [Akademischer Betreuer] Ernst. "Gypsum scaling during reverse osmosis desalination − characterization and effects of natural organic matter / Jan Benecke ; Betreuer: Mathias Ernst." Hamburg : Universitätsbibliothek der Technischen Universität Hamburg-Harburg, 2018. http://d-nb.info/117190018X/34.

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Qadar, Rebeen Nasruldeen. "Investigations into the effectiveness of large size membrane elements for RO desalination RO: water treatment by reverse osmosis." Thesis, Curtin University, 2013. http://hdl.handle.net/20.500.11937/2365.

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Operational data on Reverse Osmosis application in Sea Water Desalination were acquired for 8- and 16-inch membrane system; their performances and effectiveness in terms of specific flux, recovery, salt rejection, pressure drop across membranes components and power consumption were compared; and the results now provides a compendium on effectiveness of small and large size membrane elements for RO desalination presenting a tool for making selective decision for the optimisation of available capital and resource utilisation.

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Al-Shayji, Khawla Abdul Mohsen. "Modeling, Simulation, and Optimization of large-Scale Commercial Desalination Plants." Diss., Virginia Tech, 1998. http://hdl.handle.net/10919/30462.

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This dissertation introduces desalination processes in general and multistage flash (MSF) and reverse osmosis (RO) in particular. It presents the fundamental and practical aspects of neural networks and provides an overview of their structures, topology, strengths, and limitations. This study includes the neural network applications to prediction problems of large-scale commercial MSF and RO desalination plants in conjunction with statistical techniques to identify the major independent variables to optimize the process performance. In contrast to several recent studies, this work utilizes actual operating data (not simulated) from a large-scale commercial MSF desalination plant (48 million gallonsper day capacity, MGPD) and RO plant (15 MGPD) located in Kuwait and the Kingdom of Saudi Arabia, respectively. We apply Neural Works Professional II/Plus (NeuralWare, 1993) and SAS (SAS Institute Inc., 1996) software to accomplish this task. This dissertation demonstrates how to apply modular and equation-solving approaches for steady-state and dynamic simulations of large-scale commercial MSF desalination plants using ASPEN PLUS (Advanced System for Process Engineering PLUS) and SPEEDUP (Simulation Program for Evaluation and Evolutionary Design of Unsteady Processes) marketed by Aspen Technology, Cambridge, MA. This work illustrates the development of an optimal operating envelope for achieving a stable operation of a commercial MSF desalination plant using the SPEEDUP model. We then discuss model linearization around nominal operating conditions and arrive at pairing schemes for manipulated and controlled variables by interaction analysis. Finally, this dissertation describes our experience in applying a commercial software, DynaPLUS, for combined steady-state and dynamic simulations of a commercial MSF desalination plant. This dissertation is unique and significant in that it reports the first comprehensive study of predictive modeling, simulation, and optimization of large-scale commercial desalination plants. It is the first detailed and comparative study of commercial desalination plants using both artificial intelligence and computer-aided design techniques. The resulting models are able to reproduce accurately the actual operating data and to predict the optimal operating conditions of commercial desalination plants.
Ph. D.

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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.
www.ima.kth.se

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Rebello, de Andrade Filipe. "Hydrogen as energy backup for the Hexicon : A case study on Malta." Thesis, KTH, Energiteknik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-118853.

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The island of Malta is highly reliant on fossil fuels for its power (99%), and due to climate mitigation policies implemented by EU the Maltese government is required to have 10% of its power generation from renewables by 2020. To achieve these energy goals, the Maltese government has expressed interest in investing on a Hexicon platform to produce 9% of the Maltese energy demand. The Hexicon platform is a floating structure capable of carrying a wide range of renewable energy generators. The Hexicon platform proposed for Malta is meant to have a rated capacity of 54MW distributed by vertical and horizontal wind energy converters. Nevertheless, due to the irregular nature of wind the Hexicon platform would still use diesel generators on-board as backup power; this inherently defeats the purpose of the Maltese investment, and therefore a Hydrogen backup system was proposed and investigated for its technical and economic viability. A literature study was carried out on renewable hydrogen system in order to familiarise with the type of markets and the best way to apply the technology to the scenario at hand. Four markets were established, small-scale, transportation, stand-alone power systems, and large buffering systems; the large buffering system is the most appropriate for the study, and taking this type of system into account, the most appropriate hydrogen generation and utilisation system were then identified. It was established that the system is composed of three parts, electrolyser, storage tanks and fuel cells stacks. However, an additional water purification system is necessary; this is due to the fact that the Hexicon platform will be located offshore, and salt water is not appropriate for the electrolyser. A literature study was then performed to identify the most appropriate equipment for each stage of the process; it was established that a Reverse Osmosis (RO) system will be used to purify the water, an alkaline electrolyser will be used to generate the Hydrogen, the Hydrogen will then be stored in pressure vessels (at 30bar), thus also requiring compressors, and the recovery of energy will be performed by a proton exchange membrane (PEM) fuel cell (FC) stack. A study was carried out to establish the models to use for each equipment, and based on the hourly demand for Malta, as well as the hourly winds, a first estimate of the size of each equipment was established. The system model was developed in the HOMER software, which unfortunately did not model the desalination plant. The Hexicon (in the design considered in this study) is not able to provide Malta with 9% of the energy demand; this was mainly due to the low wind conditions. In addition to this, it was understood from the literature study that a hydrogen system backup system, i.e. a buffering system, would not be applicable to the scenario initially proposed in this thesis due to the low renewable energy penetration, and also due to the fact that the Hexicon would be connected to the grid, rendering such a system defunct. A micro-grid scenario was assumed and developed. This scenario tried to assess how low the demand would need to be in order to make a hydrogen project feasible. Different percentages were tried and the only one that met the constraints was one with 1.1% of the Maltese demand. The system would consist of a 3MW Fuel Cell, a 4.5MW electrolyser, and hydrogen storage for 10.5tonnes. The NPC of this system would be approx. 130 Million €, with an initial investment of approx. 71 Million €, LCOE of 0.257€.kWh-1, and a Hydrogen cost of approx. 20€.kg-1. While other economic indicators show viability, for example, a short payback time of 3.5 years based on the revenue from the excess electricity, the cost of hydrogen suggests that it is too expensive.

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Odeh, Ibrahim Khalil. "Modelling, field data analysis and economics of photovoltaic water pumps and the prospects for integrating desalination using reverse osmosis." Thesis, University of Ulster, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.419108.

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Greco, Francesca. "Design of an innovative wind pile for water desalination." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2018.

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L’aumento dei consumi e i mutamenti climatici in atto stanno prosciugando le risorse del pianeta, tra cui le riserve di acqua dolce. Tuttavia, un potenziale enorme è rappresentato dagli oceani, che costituiscono il 97% dell’acqua che ricopre il nostro pianeta. La desalinizzazione dell’acqua di mare è un sistema già diffuso ma, ad oggi, la maggior parte degli impianti sono alimentati da fonti di energia non rinnovabili. Il passaggio a una produzione di acqua dolce sostenibile, seppur necessario, è ancora in fase iniziale. La dissalazione con membrane a osmosi inversa prevede il pompaggio di acqua salata attraverso una membrana semipermeabile, che lascia passare le molecole di acqua e trattiene i sali disciolti. Nella presente tesi, la pressurizzazione dell’acqua di mare che alimenta il processo di osmosi inversa avviene per mezzo di turbine eoliche a trasmissione idraulica. Rispetto alle convenzionali turbine eoliche, il classico sistema di trasmissione di potenza nella carlinga è sostituito da una pompa ad acqua a pistone radiale ed una linea idraulica. Tra le sfide che questa soluzione presenta, conciliare la necessità del processo di osmosi inversa di avere un input costante con la variabilità e imprevedibilità della risorsa eolica è una delle maggiori. Lo scopo di questa tesi è stato quello di analizzare il comportamento dinamico di membrane a osmosi inversa quando usate in combinazione con una turbina a trasmissione idraulica, per mezzo dello sviluppo di un modello numerico, e confrontare i risultati ottenuti con quelli di una turbina eolica convenzionale. Parallelamente, una possibile applicazione è stata individuata nell’Isola di Pantelleria, i cui dati anemometrici sono stati utilizzati per generare gli input per il modello numerico. Seppur con varie semplificazioni, grazie al modello sviluppato è stato possibile effettuare un primo design per i principali componenti del sistema e simulare la produzione di acqua annuale per l’isola di Pantelleria.

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Asempour, Farhad. "Fabrication and Characterization of Novel Environmentally Friendly Thin Film Nanocomposite Membranes for Water Desalination." Thesis, Université d'Ottawa / University of Ottawa, 2017. http://hdl.handle.net/10393/36737.

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Thin film Nanocomposite (TFN) membranes are a relatively new class of high-performance semipermeable membranes for Reverse Osmosis (RO) applications. Large scale applications of TFN membranes have not been achieved yet due to the high production cost of the nanoparticles, agglomeration of the nanoparticles in the thin polyamide matrix of the membrane, and leaching out of typically toxic inorganic nanoparticles into the downstream. In this work, these challenges are addressed by incorporation of two different nanofillers: Cellulose NanoCrystals (CNC), and surface functionalized Halloysite NanoTubes (HNT). Amine groups, carboxylic acid groups, and the first generation of poly(amidoamine) (PAMAM) dendrimers were used for functionalization of the HNT. CNC and HNT are environmentally friendly, low/non-toxic, abundant, and inexpensive nanoparticles with a unique size, and chemical properties. TFN membranes were synthesized via in situ interfacial polymerization of m-phenylenediamine (MPD) with trimesoyl chloride (TMC) and the nanoparticles. The control Thin Film Composite (TFC) membranes, and CNC and HNT based TFN membranes were characterized by Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), X-Ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Fourier Transform Infrared spectroscopy (FTIR) and contact angle measurements. The antifouling capacity of CNC based membranes was investigated with a solution of Bovine Serum Albumin (BSA) as the fouling agent. Also, the leachability of the HNT from the membranes was examined by shaking the membranes in a batch incubator for 48 h, and then tracing the leached out HNT using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Separation characteristics of the membranes were studied by desalination of synthetic brackish water with a cross flow RO filtration system. It was revealed that incorporation of functionalized HNT enhanced the permeate flux without sacrificing the salt rejection (99.1 % ± 0.1 %). Also, incorporation of 0.1% (w/v) CNC doubled the permeate flux (from 30 to 63 L/m2.h at 20 bar) without compromising the salt rejection (97.8%). At the same time, leaching out of HNT from the TFN membranes was decreased as a result of the HNT functionalization and formation of covalent bonds with the TMC. Also, antifouling properties of the CNC-TFN membranes were 11% improved in comparison with control TFC membrane.

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Righton, Russel. "Development of an artificial neural network model for predicting the performance of a reverse osmosis (RO) unit." Thesis, Curtin University, 2009. http://hdl.handle.net/20.500.11937/1684.

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Desalination is one of the most widely used techniques to produce pure water from seawater, groundwater, wastewater or brackish water. This technique has gained wide spread acceptance throughout the world especially in arid and dry regions like the Middle East which possesses the largest capacity desalination plants in the world. On the other hand, Australia which is characterised by its arid regions does not utilise desalination as a source of providing pure water as compared to the Middle Eastern regions. The increasing population in the capital cities and the inhabitants of the isolated mining towns and smaller remote communities would benefit from using desalination. Reverse Osmosis (RO) is the one the widely used desalination technique in the world. It offers the distinct advantage over the other desalination techniques because it consumes low energy, provides a high quality final product, easy installation and flexible design. RO works on the principle of osmosis where the transfer of the solvent is done through a semi permeable membrane under the influence of a concentration gradient. The quality of the pure water that passes through the membrane during the RO process is a function of the difference between the applied pressure and the osmotic pressure of the solution.From the results obtained the simulated results for solute rejection and permeate flux are close to the analytical i.e. experimental obtained results. Traditionally membrane performance has been predicted by polynomial correlations but the neural network model offers the advantage allowing the user to visualise the entire operation, capability of learning from the experimental results and obtaining highly accurate findings. The model generated in this study will provide the solid foundation for extending the ANN model applicability to cover several feedwater sources over a range of different pressures and concentrations.The thesis describes the development of an Artificial Neural Network Model for predicting the two important parameters of Reverse Osmosis i.e. salt rejection and permeate flux. The thesis comprises of six sections including the conclusions and recommendations for future work.Chapter details the general background of the current state of water supplies in Australia, looks at the existing RO plants that have been set up or being planned for the future and establishes the various uses of RO practices.Chapter 2 contains a detailed literature review on desalination and its various processes, understanding the way RO works and the factors that affect the RO operation and performance.Chapter 3 presents the modelling approach used during this study and introduces the reader to artificial neural networks and the manner in which they function.Chapter 4 contains a brief description of the experimental procedures conducted by Nasir (2005) and this experimental data forms the basis for the model development.Chapter 5 deals with the development of the artificial neural network model for predicting the performance of a RO system handling different feedwater sources and validation of the developed ANN model.Chapter 6 presents the conclusions obtained from this study and the recommendations for future work to be conducted in order to expand the developed ANN code to cover different feedwater samples.

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Dissertations / Theses on the topic 'Reverse osmosis desalination'

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