Yes / Brackish water can be considered an important source of fresh water, via desalination, especially for arid districts. Reverse Osmosis (RO) process has been successfully used to produce fresh water from brackish water sources. However, there is still the challenge of improving the performance of multistage RO desalination plants. From the selection of the RO configurations to the selection of the appropriate type of membranes and the operating conditions at the end determines the performance of RO process in terms of recovery, salt rejection, energy consumptions and ultimately the cost of production of freshwater. Using model-based simulation, this work attempts to investigate the most suitable types of membranes for an industrial scale RO plant from a set of different membrane brands that would attain the highest-performance at lowest specific energy consumption (SEC). As a case study, we considered a multistage multi-pass medium-scale RO plant (1200 m3/day) of Arab Potash Company (APC, Jordan) which produces high quality water for the boilers after pre-treatment stage. The simulation results confirmed that employment of the Filmtec BW30LE-440 would increase water recovery by about 22% besides reducing the product salinity and SEC by about 15% and 10%, respectively compared to the existing membrane.

Yes / In this work, we considered model-based simulation and optimisation of a medium scale brackish water desalination process. The mathematical model is validated using actual multistage RO plant data of Al- Hashemite University (Jordan). Using the validated model, the sensitivity of different operating parameters such as pump pressure, brackish water flow rate and seasonal water temperature (covering the whole year) on the performance indicators such as productivity, product salinity and specific energy consumption of the process is conducted. For a given feed flow rate and pump pressure, winter season produces less freshwater that in summer in line with the assumption that winter water demand is less than that in summer. With the soaring energy prices globally, any opportunity for the reduction of energy is not only desirable from the economic point of view but is an absolute necessity to meet the net zero carbon emission pledge by many nations, as globally most desalination plants use fossil fuel as the main source of energy. Therefore, the second part of this paper attempts to minimise the specific energy consumption of the RO system using model-based optimisation technique. The study resulted not only 19 % reduction in specific energy but also 4.46 % increase in productivity in a particular season of the year. For fixed product demand, this opens the opportunity for scheduling cleaning and maintenance of the RO process without having to consider full system shutdown.

Submitted by Eunice Novais (enovais@uepg.br) on 2018-06-26T19:10:46Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Ana Carolina M. Rodrigues.pdf: 2130324 bytes, checksum: 0340ff571493224c3f33ecd693bb1e77 (MD5) / Made available in DSpace on 2018-06-26T19:10:46Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Ana Carolina M. Rodrigues.pdf: 2130324 bytes, checksum: 0340ff571493224c3f33ecd693bb1e77 (MD5) Previous issue date: 2018-04-12 / Fundação Araucária de Apoio ao Desenvolvimento Científico e Tecnológico do Paraná / A má distribuição de água doce no mundo, o crescimento populacional acentuado, as mudanças climáticas e as consequências das ações antropológicas traz a necessidade da busca de fontes alternativas para suprir a demanda de água aos seres humanos, animais e plantas. A abundância de água salgada ou salobra é muitas vezes, a única fonte de água disponível para sobrevivência de algumas comunidades no planeta, isso tem impulsionado o uso de técnicas de dessalinização. Com o objetivo de estudar alternativas para adaptações climáticas, antecipar tendências e problemas hídricos futuros foi implantado um sistema de dessalinização de água salobra, em escala piloto, nas dependências da Estação de Tratamento de Água (ETA) da Sanepar, em Praia de Leste, no município de Pontal do Paraná no litoral do estado. O sistema piloto foi provido de ultrafiltração (UF) como pré-tratamento seguido de abrandamento e da dessalinização por osmose reversa (OR). Com capacidade para produzir 1 m3.h-1 de água tratada. A água salobra foi padronizada nas concentrações de 1000 ± 50 mg.L-1 e 1500 ± 20 mg.L-1 de sólidos dissolvidos totais (SDT), por meio da mistura da água do mar e da água bruta do Rio das Pombas, manancial que abastece o balneário. Avaliou-se o sistema global a partir de dados de produção e consumo de água, balanço de massa e das taxas de recuperação para configurações diferentes do sistema de OR. Para isso, foram realizados quatro experimentos, variando a configuração de abertura do registro do concentrado da OR: o primeiro com abertura de 72,71% de concentrado (A); o segundo 59,20 % (B); o terceiro 39,70% (C), estes com 1500 ± 20 mg.L-1 de SDT; o quarto experimento foi realizado para 1000 ± 50 mg.L-1 de SDT com abertura de 32,90% de concentrado (D). Aproximadamente 15% do volume de alimentação era utilizado na limpeza hidráulica das membranas da UF e da OR. Quanto maiores as vazões do concentrado da OR, maior a vazão de alimentação, e consequentemente, menor a taxa de recuperação e pressão osmótica. A maior taxa de recuperação obtida foi de 69,13% para o experimento D, sendo considerada a configuração mais otimizada. / With the unequal distribution of fresh water in the world, strong population growth, climate change and the consequences of anthropological actions it is necessary to look for alternative sources to supply the water demand for human beings, animals and plants. Salt water or brackish water has been the only source of water available for survival in some communities on the planet. This issue has driven the use of desalination techniques. With the objective of studying alternatives for climate adaptation, anticipating of trends and problems and water problems, a brackish water desalination system in pilot scale was implemented on the premises of the Water Treatment Plant Station, in Praia de Leste, in the Pontal do Paraná City, coast of the State. The pilot system was provided with ultrafiltration (UF) as a pretreatment followed by softening and reverse osmosis (RO), with the capacity to produce 1m3.h-1 of permeate. Brackish water was produced at concentrations of 1,000 ± 50 mg.L-1 and 1,500 ± 20 mg.L-1 of total dissolved solids (TDS), by mixing sea water and fresh water from the Pombas River, which supplies the town. The global system was evaluated from production and water consumption data, mass balance and recovery rates for different configurations of the reverse osmosis system. For this, four experiments were performed, varying the configuration of the valve which controls the flow of the brine: the first one with 72.71% (A); the second with 59.20%(B); the third with 39.70% (C), these with 1,500 ± 20 mg.L-1 of TDS; the fourth experiment was also performed for 1,000 ± 50 mg.L-1 of TDS with 32.90% of the brine (D). About 15% of volume of water produced was used in the hydraulic cleaning of the UF and RO membranes. When the flow rates of the concentrate were higher, the feed rates were also higher and consequently, the recovery rates and osmotic pressure were lower. The highest recovery rate was 69.13% for the experiment D, being considered the most optimized configuration.

Foram realizadas análises isotópicas, físicas e químicas na água, no solo e nas plantas do Sistema de Produção Integrado Utilizando Efluentes de Dessalinização, criado pela Embrapa Semiárido, como uma alternativa para a reutilização desses efluentes na produção de alimentos e diminuição do impacto ambiental causado pelo descarte incorreto deste rejeito. O sistema avaliado se localiza no Campo Experimental da Caatinga, na Embrapa Semiárido (Petrolina-PE). Os resultados encontrados quanto à ciclagem dos nutrientes indicaram a ocorrência de uma contínua adição dos cátions Ca+2, Mg+2 , K+ e Na+ no solo durante o experimento, de 199 kg ha-1, 88 kg ha-1, 51 kg ha-1 e 142 kg ha-1, respectivamente. A eficiência de retirada do Ca+2, Mg+2 e Na+ pela Atriplex nummularia foi de 12,1, 4,3 e 23,9%, respectivamente; Ocorreu uma elevada perda de nitrogênio no sistema causado pelo processo de denitrificação, que diminuiu a concentração de nitrogênio em 72% do inicio ao final do sistema, levando este nutriente em quantidades insuficientes para a área agrícola. Estes resultados serão utilizados para indicar caminhos de melhorias no sistema. Ainda, quanto aos resultados isotópicos, foi possível concluir que: a água sofre um fracionamento durante o processo de osmose reversa na ordem de 1,87 para o 18O e 10,3 para o 2H; A água do poço é formada por uma mistura de águas recentes e paleoáguas; A relação 18O vs 2H; possui um coeficiente angular de 4,1, indicando elevada evaporação neste elemento; O solo avaliado possui uma média isotópica de -24 de 13C no solo de caatinga e -20 de 13C na área experimental, indicando uma troca da matéria orgânica desta área por material proveniente da Atriplex, que teve uma razão isotópica média de -13,7 .de 13C. / Isotopic, physical and chemical analysis were performed in water, soil and plants of the \" Integrated Production System Using Wastewater Desalination \", created Embrapa Semiarid, as an alternative to reuse of wastewater for food production and reducing the environmental impact caused by the incorrect disposal of the reject. The evaluated system is located in the Experimental Área Caatinga at Embrapa Semi-Arid (Petrolina-PE). The findings about the cycling of nutrients indicated the occurrence of a continuous addition of Ca+2, Mg+2, K+ and Na+ in the soil during the experiment of, 199 kg ha-1, 88 kg ha-1, 51 kg ha-1 and 142 kg ha-1, respectively. The efficiency of removal of Ca+2, Mg+2 and Na+ by Atriplex nummularia was 12,1, 4,3 and 23,9% respectively; Was observed high loss of nitrogen in the system caused by denitrification process, which decreased the concentration of nitrogen by 72% from beginning to end system, taking this nutrient in insufficient quantities to agricultural area. These results will be used for indicate ways to improve the system. Also, with the isotopic results was concluded that: water undergoes fractionation during the process of reverse osmosis the order of 1,87 to 18O and 10,3 for 2H; The well water is formed by a mixture of recent water and paleoáguas; The relationship 18O vs 2H; has a slope of 4,1, indicating high evaporation of this element; The soil has an average rated -24 in isotopic 13C in savanna soi and -20 of 13C in the experimental area, indicating an exchange of matter of this area of organic material from Atriplex, which had an average isotopic ratio of -13,7 . of 13C.

Submitted by Eunice Novais (enovais@uepg.br) on 2018-07-31T12:05:01Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Tatiane Bovaroti.pdf: 1677408 bytes, checksum: 74791391260b47b48abc127d7af4af68 (MD5) / Made available in DSpace on 2018-07-31T12:05:01Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Tatiane Bovaroti.pdf: 1677408 bytes, checksum: 74791391260b47b48abc127d7af4af68 (MD5) Previous issue date: 2018-04-12 / Preocupados com a intrusão de água do mar, escassez e má qualidade das reservas de água doce no mundo, diversos países têm estudado e proposto sistemas de alta tecnologia que sejam viáveis para a dessalinização de água salobra ou salina. Este trabalho teve como objetivo principal avaliar a eficiência de um sistema de ultrafiltração (UF) como pré-tratamento, seguido de abrandamento e osmose reversa (OR) para a dessalinização de água salobra em escala piloto, instalado no balneário de Praia de Leste, litoral do estado do Paraná. Para a obtenção da água salobra foi realizada a mistura da água do rio das Pombas com a água do mar até a concentração de 1500 (± 100) mg. L-1 de sólidos dissolvidos totais (SDT). O sistema foi projetado para a produção de 1 m3.h-1 de água doce (permeado da OR) e operou por aproximadamente 3h por dia durante vinte dias não consecutivos. Analisaram-se amostras de nove pontos de coleta durante a primeira (A), segunda (B) e terceira (C) hora de operação. Para a avaliação da qualidade da água os parâmetros analisados foram: SDT, condutividade elétrica, pH, temperatura, cor aparente, turbidez, alcalinidade total, dureza total, cálcio, cloreto, sulfato, coliformes totais e E.coli. Para avaliação da eficiência do sistema, calculou-se a taxa de recuperação e o fluxo de filtração, bem como a leitura de outros parâmetros operacionais como a pressão osmótica. O sistema de UF apresentou remoção média de 95,1% de turbidez e de 98,6% de cor aparente na água salobra. Constatou-se ausência de coliformes totais e E.coli no permeado. Houve variação quanto à remoção de dureza total e cálcio pelo abrandador devido ao tempo de regeneração do sistema. O sistema de OR obteve remoção média de 99,4% de SDT e a maior taxa de recuperação global (UF e OR) foi de 57,4%. / Concerned about the intrusion of sea water, scarcity and poor quality of freshwater reserves in the world, several countries have studied and proposed high technology systems that are feasible for the desalination of brackish or saline water. The main objective of this work was to evaluate the efficiency of an ultrafiltration (UF) system as a pretreatment, followed by slowing and reverse osmosis (RO) for pilot scale saline water desalination, installed in Praia de Leste – coast of the state of Paraná. To obtain the brackish water, the water of the Pombas River was mixed with sea water up to the concentration of 1500 (± 100) mg. L-1 total dissolved solids (TDS). The system was designed to produce 1 m3.h-1 of freshwater (permeate from the RO) and was operated by approximately 3 hours per day during twenty non-consecutive days. Samples from nine collection points were analyzed during the first (A), second (B) and third (C) hours of operation. In order to evaluate the water quality, the parameters evaluated were: TDS, electric conductivity, pH, temperature, apparent color, turbidity, total alkalinity, total hardness, calcium, chloride, sulfate, total coliforms and E.coli. To evaluate the efficiency of the system, the recovery rate and the filtration flow were calculated, as well as the reading of other operational parameters such as osmotic pressure. It was found absence of total coliforms and E. coli in the permeate. There was variation regarding to the removal of total hardness and calcium by the softener due to the regeneration time of the system. The RO system obtained an average of 99.4% of the TDS removal and the highest overall (UF and RO) recovery rate was 57.4%.

Abstract in English and German / The reported PhD research study was conceived from real water problems experienced by a rural community in South Africa (SA). Specifically, water quality in the Nandoni Dam situated in the Vhembe District, Limpopo Province, South Africa was assessed in order to determine its fitness for use, following complaints by community members using this water for drinking and domestic purposes. The dam supplies water to 55 villages with approximately 800 000 residents. At the inception of the study, there was little scientific information relating to the quality of the water in the dam. Water samples from various sites across the Nandoni Dam, a primary source of domestic water supply in the region, were collected through each season of the year over a period of 12 months to ascertain the concentrations of dissolved salts in the dam. Additionally, harmful polycyclic aromatic hydrocarbons (PAHs) and phenols were assessed. The concentrations of the ions contributing to water salinity were generally lower than the brackish water bracket (i.e. 500 – 30 000 mg/L) but too high for potable water. The concentration of the phenols was relatively higher than the threshold limit of drinking water. Therefore, the water sourced from the Nandoni Dam was found not suitable for human consumption and therefore required integrated water resource management, as well as robust and cost-effective water treatment especially since the salinity of the water was high even after treatment by a water treatment plant sourcing water from the dam. In an attempt to develop a suitable energy-efficient technology or system for complete removal of salts (desalination) from the salty water (including brackish water), electrospun polyvinylidene fluoride (PVDF) nanofibre membranes were synthesised and evaluated for removal of salts using the Direct Contact Membrane Distillation (DCMD) process. The nanofibre membranes were synthesised with combined high mechanical stability, porosity, and superhydrophobicity to prevent fouling and wetting while maintaining high salt rejection and water flux. Organically functionalised silica nanoparticles (f-SiO2NPs) were embedded on PVDF nanofibre membranes using an in-situ electrospinning technique for superhydrophobicity enhancement. These modified membranes displayed Young’s modulus of ~43 MPa and showed highly porous properties (~80% porosity, 1.24-1.41 μm pore sizes) with superhydrophobic surfaces (contact angle >150°). Membranes embedded with octadecyltrimethoxysilane (OTMS), and chlorodimethyl-octadecyl silane (Cl-DMOS), octadecyltrimethoxysilane (ODTS)-modified SiO2NPs were the most efficient; rejecting >99.9% of NaCl salt, with a water flux of approximately 30.7-34.2 LMH at 60°C, thus indicating their capacity to produce potable water. The superhydrophobic membranes were coated with a thin layer consisting of carboxylated multiwalled carbon nanotubes (f-MWCNTs) and silver nanoparticles (AgNPs) to reduce membrane fouling. The AgNPs and f-MWCNTs were uniformly distributed with size diameters of 28.24±1.15 nm and 6.7±2.1 nm respectively as evidenced by transmission electron microscopy (TEM) micrographs. The antibacterial AgNPs embedded in the PVDF nanofibre membranes inhibited the growth of Gram-positive Geobacillus stearothermophilus and Staphylococcus aureus as well as Gram-negative Pseudomonas aeruginosa and Klebsiella pneumoniae indicating their potential to prevent biofilm formation. Fouling tests were conducted using bovine serum albumin (BSA), sodium alginate, colloidal silica, and thermophilic bacteria effluent as model organic, inorganic, and bio-foulants, respectively, using DCMD. The uncoated membranes were characterised by a flux decays ranging from 30% to 90% and salt rejection decays ranging from 1.4% to 6.1%. Membrane coating reduced the flux and salt rejection decays to 10–24% and 0.07–0.75%, respectively. Although the initial flux decreased from 42 to  16 LMH when using coated membranes, the resistance of these coated membranes to water flux and salt rejection decays indicated that coating could be a suitable one-step solution for fouling mitigation in DCMD. The major challenge would be to design the MD membranes with architectures that allow a high-water flux to be maintained i.e., a highly porous layer. Furthermore, the volatile compounds bearing hydrophobic groups were pretreated to reduce their fouling capacity on PVDF nanofibre membranes. In this study, polyacrylonitrile (PAN) and polyethylene-imine (PEI) functionalised-PAN nanofibre membranes were synthesised and evaluated as a pretreatment for the removal of chlorophenol and nitrophenol from solutions. Under optimised experimental conditions, adsorption capacities ranging from 27.3 – 38.4 mg/g for PAN and PEI-modified nanofibres, respectively, were recorded. The PEI-functionalised nanofibres showed a high potential as a pretreatment step to be integrated to MD process. Ultimately an integrated water desalination system was developed. This involved a pretreatment filter (pore size ~100 μm) containing PEI-functionalised PAN nanofibre materials to reduce particulates and large molecules of dissolved organic/inorganic compounds from the water to be treated. In this research, it was observed that the pre-treatment step was not sufficient in removing all traces of compounds causing fouling of the superhydrophobic PDVF nanofibre membranes. As such, coating of the membranes with a thin hydrophilic layer and coupled with the filtration pretreatment step was found to provide fouling-resistance properties, high salt rejection, and low flux decays on brackish water collected at an estuary in Belgium and the Nandoni Dam in South Africa, demonstrating the potential of the MD separation process towards potable water recovery from brackish water. / Het onderzoek in dit proefschrift was gebaseerd op concrete waterproblemen die een landelijke gemeenschap in Zuid-Afrika (SA) ervaart. In het bijzonder werd de waterkwaliteit in het Nandoni-reservoir in het Vhembe-district in de provincie Limpopo in Zuid-Afrika onderzocht, om te bepalen of dit water geschikt is voor gebruik, na klachten van leden van de gemeenschap die dit water gebruiken als drinkwater en voor huishoudelijk gebruik. Het reservoir levert water aan 55 dorpen met ongeveer 800.000 inwoners. Bij het begin van het onderzoek was er weinig wetenschappelijke informatie over de kwaliteit van het water in het reservoir. Watermonsters van verschillende locaties in het reservoir, dat een primaire bron van drinkwater is in de regio, werden gedurende verschillende seizoenen van het jaar verzameld over een periode van 12 maanden, om de concentraties van de meest voorkomende ionen in het reservoir te bepalen. Bovendien werden de concentraties van schadelijke polycyclische aromatische koolwaterstoffen (PAK's) en fenolen gemeten. De concentraties van de ionen die bijdroegen aan het zoutgehalte van het water waren in het algemeen lager dan de drempel om het water als brak water te bestempelen (dat wil zeggen 500 – 30 000 mg/l), maar waren te hoog voor drinkwater. De concentratie van de fenolen was hoger dan de limiet voor drinkwater. Daarom bleek het water afkomstig van het Nandoni reservoir niet geschikt voor menselijke consumptie. Een beter geïntegreerd waterbeheer is dus nodig om deze bron voor drinkwater te beschermen, naast een robuuste en kosteneffectieve waterbehandeling. Deze waterbehandeling moet vooral het zoutgehalte van het water naar beneden halen, maar ook de concentraties van fenolen. In een poging om een geschikte energie-efficiënte technologie of een systeem voor de volledige verwijdering van zouten (~ontzilting) uit brak water te ontwikkelen, werden elektrisch gesponnen polyvinylideenfluoride (PVDF) nanovezelmembranen gesynthetiseerd en beoordeeld op verwijdering van zouten met behulp van Direct Contact Membraandestillatie (DCMD). De nanovezelmembranen hadden een gecombineerde hoge mechanische stabiliteit, porositeit en superhydrofobiciteit, die hielp om vervuiling (fouling) en vloeistofintrede in de poriën (wetting) te voorkomen, terwijl een hoge zoutverwijdering en hoge waterflux doorheen de membranen gehandhaafd bleven. Organische gefunctionaliseerde silica-nanodeeltjes (f-SiO2NP's) werden nadien geïncorporeerd in de PVDF nanovezelmembranen met behulp van een in-situ elektrospinning techniek om zo een nog grotere superhydrofobiciteit te bekomen. Deze gemodificeerde membranen hadden een degelijke treksterkte (Young's modulus van ~ 43 MPa) en waren zeer poreus (~ 80% porositeit, 1.24-1.41 μm poriegrootte). Het oppervlak van de membranen vertoonde inderdaad superhydrofobe eigenschappen (contacthoek met water > 150 °). De membranen ingebed met octadecyltrimethoxysilaan (ODTS) SiO2NP's waren het meest efficiënt: ze toonden een zoutretentie van> 99.9% voor NaCl, bij een waterflux van ongeveer 30.7-34.2 l/(m².h) bij 60 ° C (ten opzichte van 20°C in het permeaat), wat aangeeft dat ze in staat zijn om drinkbaar water te produceren. De superhydrofobe membranen werden nadien ook gecoat met een dunne laag bestaande uit gecarboxyleerde multiwall-carbon nanotubes (f-MWCNT's) en zilver nanodeeltjes (AgNP's), in een poging om membraanvervuiling te verminderen. De AgNP's en f-MWCNT’s hadden uniforme diameters van respectievelijk 28,24 ± 1,15 nm en 6,7 ± 2,1 nm (zoals bleek uit transmissie-elektronenmicroscopie (TEM)). De antibacteriële AgNP's ingebed in de PVDF-nanovezelmembranen remden de groei van Gram-positieve Geobacillus stearothermophilus en Staphylococcus aureus bacteriën, evenals Gram-negatieve Pseudomonas aeruginosa en Klebsiella pneumoniae bacteriën. Dit toont het potentieel van deze membranen om biofilmvorming te voorkomen. Vervuilingsproeven (in DCMD) werden uitgevoerd met behulp van runderserumalbumine (BSA), natriumalginaat, colloïdaal silica, en thermofiele bacteriën - als respectievelijk organische, anorganische en biologische vervuiling. De niet-gemodificeerde membranen werden gekenmerkt door een fluxverval, met een daling van de flux met 30% tot 90%, naast een daling van de zoutretentie met 1.4% tot 6.1%. Bij de gecoate membranen daalde de flux slechts met 10-24% en de zoutverwijdering slechts met 0.07-0.75% respectievelijk. Hoewel de initiële flux ook afnam (van 42 naar ± 16 l/(m².h)) bij het gebruik van gecoate membranen, toonde de hogere weerstand tegen vervuiling van deze gecoate membranen aan dat deze coating een geschikte oplossing zou kunnen zijn tegen vervuiling in DCMD. Bovendien kan de synthese in één stap verlopen. De grootste uitdaging zal echter zijn om MD-membranen te ontwerpen waarbij de coating de oorspronkelijke waterflux/de porositeit van de membranen niet teveel verlaagt. Daarnaast werden gemodificeerde PVDF nanovezels geproduceerd om de verwijdering van vluchtige, hydrofobe stoffen (zoals fenolen) door adsorptie aan deze vezels te verhogen. Er werden polyacrylonitril (PAN) en polyethyleen-imine (PEI) gefunctionaliseerde PAN nanovezels gesynthetiseerd, waarna deze geëvalueerd werden als adsorbens (en dus voorbehandeling voor de membraanstap) voor chloorfenol en nitrofenol. Onder geoptimaliseerde experimentele omstandigheden werden adsorptiecapaciteiten tussen respectievelijk 27.3 en 38.4 mg / g voor PAN- en PEI-gemodificeerde nanovezels gemeten. De PEI-gefunctionaliseerde nanovezels vertoonden een hoog potentieel als een voorbehandelingsstap voor de hierboven beschreven DCMD. Tenslotte werd ook een geïntegreerd waterontziltingssysteem ontwikkeld. Dit systeem bestond uit een voorbehandelingsstap met PEI-gefunctionaliseerde PAN-nanovezels (in de vorm van een membraan met poriegrootte ~100 μm), gevolgd door een gemodificeerde DCMD stap. De voorbehandeling diende om deeltjes en grote opgeloste organische verbindingen uit het te behandelen water te verwijderen voor de DCMD-stap. In dit onderzoek werd waargenomen dat de voorbehandelingsstap niet voldoende was om alle organische contaminanten te verwijderen die vervuiling veroorzaakten op de superhydrofobe PDVF nanovezelmembranen in de DCMD-stap. Toch bleek coating van de DCMD membranen met een dunne hydrofiele laag (gekoppeld aan de voorbehandelingsstap) een voldoende bescherming tegen vervuiling te bieden zodat de zoutretentie en waterflux van deze membranen hoog bleef. De combinatie van voorbehandeling – gemodificeerde DCMD werd succesvol getest op water uit de Schelde en uit het Nandoni reservoir, waarmee het potentieel van de technologie om drinkwater uit brak water te produceren werd aangetoond. / School of Science / Ph.D. (Applied Biological Science : Environmental Technology)

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.

Brackish springs are relatively frequent phenomena in coastal carbonate formations and their existence has been extensively reported in Mediterranean coasts. In fact, more than 300 brackish springs have been identified only in the coast of the former Yugoslavia. They essentially consist of inland or submarine karst outlets discharging waters with flow-dependent salinity. The phenomenon is particularly surprising in inland springs, where high flow rates with significant salinities (presumably coming from the sea) may be discharged several meters above sea level. In addition to its scientific interest, brackish springs hold a strategic potential as a source of water in areas with often limited water resources. In order to design their appropriate management a quantitative understanding of their controlling mechanisms both in general and at every particular spring has to be achieved.These mechanisms have been studied for many years but some controversy still remains. It is clear that they are related to deep well developed karst systems. Under these conditions, groundwater flows in a turbulent mode through a network of interconnected conduits immersed in a porous matrix with slow Darcyan flow velocities. Surprisingly, different models to explain the functioning of the system, although based on different conceptual and methodological approaches lead to similar results. This sugests that a global study on the salinitzation mechanisms of brackish springs should be undertaken. Here, we first derive the equations governing turbulent flow for density-dependent fluids and describe different mechanisms of salinization of inland brackish springs, in order to compare with the spring discharge and concentration response for those mechanisms of salinization.The insights gained in this analysis are applied to the study of S'Almadrava spring (Mallorca, Spain). This spring discharges up to 2 m3/s with salinities of 20 mS/cm at an elevation of 8 m.a.s.l. It generally displays an inverse relation between discharge rate and concentration (i.e., discharging higher salinity waters for low flow rates, and vice versa). A hypothetical but geologically feasible dual permeability model is proposed to reproduce observed salinity variations for both the dry and wet seasons but also to explain the secondary salinity peaks observed after every rainfall event. Model results agree with observations, but the lack of geological information at depth impedes model validation. Therefore, a second validation of the conceptual model is undertaken based on high-frequency geochemical observations. Due to the highly dynamic conditions of the system, the geochemical data was analyzed using fully coupled reactive transport modelling. The interpretation of geochemical data not only helps on validating conceptual models but also yields information on the water-rock interaction processes occurring at deep carbonate systems. In fact, one of the processes initially proposed to explain the occurrence of well-developed karst systems at depth, is the enlargement of tectonic fissures by carbonate dissolution due to the mixing of fresh and seawater.The theory of dissolution by mixing waters is based on the fact that when two solutions are mixed, concentrations in the mixture are volume weighted averages of the two end-members, but the thermodynamic activities of the species controlling the water-mineral reactions are non linear functions of the mixing ratio. Therefore, two end-member solutions in equilibrium with a solid phase could lead to an undersaturated mixture depending on several factors, most notably CO2 content and ionic strength. Observation of mixing and carbonate dissolution at depth has not been possible because of technical difficulties. More accessible to observation is the seawater mixing zone in coastal aquifers where calcite undersaturation and/or calcite dissolution have been reported numerous times. Yet, dissolution in coastal environments is not always clear and oversaturation or lack of dissolution in mixing zones have also been described. This apparent inconsistency on field observations around the world prompted the studies of the second part of the thesis. Flow-through laboratory experiments were performed in CO2-controlled atmosphere in order to quantify the dependence of the dissolution of calcite with the mixing ratio, and the role that CO2 variations may have on enhancing the dissolution capacity of the mixture. Results show that, although dissolution occurs, the major carbonate dissolution in aquifers must be considered only in a geological time scale. Sanford and Konikow (1989) predicted the location and magnitude of long term porosity development of coastal aquifers, based on a two step method. We compare their results with a reactive transport model approach in 1D and 2D, showing that reactive transport is required to properly understand the phenomenon because it is found that dissolution is controlled not only by geochemical factors but also by the rate at which fresh and salt water mix (i.e., by dispersion).

Made available in DSpace on 2016-08-31T13:24:11Z (GMT). No. of bitstreams: 1 ChristianoRC_DISSERT.pdf: 985774 bytes, checksum: 16a5bb519ba17167ab91e67bf421f7f6 (MD5) Previous issue date: 2011-03-30 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / In Brazil, mainly in the semiarid region, a major challenge is to promote the water supply to households in rural areas. Groundwater is identified as a viable alternative to ensure the access of rural communities in the northeast to water from public investment in drilling wells. However, these water sources in most cases have use restrictions for human consumption, because they present problems of salinity. The technology of reverse osmosis has been widely used for treatment of brackish water, with successful experiences in most locations where units have been deployed in water treatment by desalination. Many rural communities in Mossoró, RN, are supplied with water from the aquifer Jandaíra, high salt concentration, which is treated in desalination plants, allowing its use for human consumption. In these communities, the reject brine of the process of desalination is not receiving any treatment or proper disposal, being dumped straight into the ground and, when used in irrigation of crops there are no scientific-technical reasons for their use, causing problems of soil salinization. Due to the impacts caused by the use of brackish or reject brine for irrigation in the soil, to enable their use should always adopt some special practices of water management and soil for salinity control. As the majority of crops grown in the region classified as sensitive to moderately sensitive to salinity, there is the need to better characterize these waters, to establish the appropriate management of plants, soil and irrigation systems. As the majority of crops grown in the region are classified as sensitive to moderately sensitive to salinity, there is the need to better characterize these waters, to establish the appropriate management of plants, soil and irrigation systems. Thus, this study aimed to evaluate the quality of water for irrigation in rural communities of Mossoró, supplied with brackish water from tube wells equipped with desalination, providing this information as a tool to aid the proper management and use of these waters irrigation. 30 rural communities were selected to perform the collection of samples of water from the waste generated in the desalination, purified and in its natural form (brackish water of the well). In the collected samples were determined at electric conductivity (ECw), pH and concentrations of Na+, Ca2+, K+, Cl-, HCO3 - e CO3 2-, in addition, the sodium adsorption ratio (SAR). The Analyses of water samples were interpreted as to risk of salinity, sodicity, toxicity of ions and other quality parameters. The results show that water of the wells rural communities studied, have restrictions to their use in agriculture, as to risks of salinity and sodicity of the soil, especially the waters of the communities: São Romão, Boa Fé and Pau Branco. the reject brine of the desalination have high concentrations of salts, especially in communities of Boa Fé and Puxa Boi, compromising their use for irrigation, and, the desalinated water, although they have low concentrations of salts have restrictions on the problems of infiltration into the soil, if by chance, are employed in irrigation. / No Brasil, principalmente na região semiárida, um grande desafio é promover o abastecimento de água às famílias residentes nas áreas rurais. As águas subterrâneas são apontadas como uma alternativa viável para garantir o acesso das comunidades rurais do nordeste à água, a partir de investimentos públicos na perfuração de poços tubulares. Entretanto, essas fontes hídricas apresentam na maioria dos casos restrições de uso para dessedentamento humano, por apresentarem problemas de salinidade.A tecnologia da osmose reversa tem sido amplamente utilizada para o tratamento da água salobra, com experiências de êxito na maioria das localidades aonde têm sido implantadas as unidades de tratamento de água por dessalinização. Muitas comunidades rurais de Mossoró, RN, são abastecidas com água proveniente do aquífero Jandaíra, de elevada concentração de sais, a qual é tratada em dessalinizadores, possibilitando sua utilização para consumo humano. Nessas comunidades, o rejeito do processo da dessalinização não está recebendo qualquer tratamento ou destinação adequada, sendo despejado diretamente no solo e, quando utilizados na irrigação de culturas não há qualquer fundamentação técnico-científica para o seu uso, causando problemas de salinização nos solos. Devido aos impactos causados pelo uso de águas salobras ou de rejeito salino na irrigação no solo, para viabilizar a sua utilização deve-se sempre adotar algumas práticas especiais de manejo da água e do solo para o controle da salinidade. Sendo a maioria das culturas exploradas na região classificadas como sensíveis a moderadamente sensíveis à salinidade, surge a necessidade de melhor caracterizar essas águas, para se estabelecer o manejo adequado das plantas, solo e sistemas de irrigação. Assim, o presente trabalho objetivou avaliar a qualidade da água para fins de irrigação de comunidades rurais de Mossoró, abastecidas com águas salobras provenientes de poços tubulares, dotados de dessalinizadores, fornecendo estas informações como uma ferramenta de auxílio para o manejo adequado da utilização destas águas na irrigação. Foram selecionadas 30 comunidades rurais para realização das coletas de amostras das águas do rejeito gerado na dessalinização, purificadas e na sua forma natural (água salobra de poço). Nas amostras coletadas foram determinadas a condutividade elétrica da água (CEa), o pH e concentrações de Na+, Ca2+, K+, Cl-, HCO3 - e CO3 2-; além disso, a razão de adsorção de sódio (RAS). As análises das amostras de água foram interpretadas quanto aos riscos de salinidade, sodicidade, toxidade de íons e outros parâmetros de qualidade. Os resultados mostram que as águas dos poços das comunidades rurais estudadas possuem restrições para a sua utilização na agricultura, quanto aos riscos de salinização e sodificação do solo, principalmente as águas das comunidades: São Romão; Boa Fé e Pau Branco; as águas de rejeito da dessalinização possuem elevadas concentrações de sais, principalmente nas comunidades de Boa Fé e Puxa Boi, comprometendo a sua utilização para a irrigação e as águas dessalinizadas, embora possuírem baixos teores de sais têm restrições quanto a problemas de infiltração no solo, caso venham a ser empregadas para irrigação.

Submitted by Lara Oliveira (lara@ufersa.edu.br) on 2017-05-23T23:17:13Z No. of bitstreams: 1 JoséDAN_DISSERT.pdf: 4366336 bytes, checksum: 608d3dd1b2cdbeef88c6fe49d0d9dfa1 (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2017-05-24T11:15:50Z (GMT) No. of bitstreams: 1 JoséDAN_DISSERT.pdf: 4366336 bytes, checksum: 608d3dd1b2cdbeef88c6fe49d0d9dfa1 (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2017-05-24T11:16:18Z (GMT) No. of bitstreams: 1 JoséDAN_DISSERT.pdf: 4366336 bytes, checksum: 608d3dd1b2cdbeef88c6fe49d0d9dfa1 (MD5) / Made available in DSpace on 2017-05-24T11:16:55Z (GMT). No. of bitstreams: 1 JoséDAN_DISSERT.pdf: 4366336 bytes, checksum: 608d3dd1b2cdbeef88c6fe49d0d9dfa1 (MD5) Previous issue date: 2016-06-02 / Agência Nacional do Petróleo, Gás Natural e Biocombustíveis / With the increasing demand of oil products, the need arises to seek more and more new extraction techniques to increase the production of barrels at the lowest possible cost. With this also comes the concern for the environment and the entire ecosystem near the mining fields. Techniques to increase the recovery factor of these wells has been developed and refined over the past few years. The heating method by microwave is a process where the electromagnetic energy at high frequency is transformed into thermal energy dielectric loss and / or electromagnetic absorption. Research using as a basis the increase of technical electromagnetic heating recovery factor is still poorly developed. The present work aim is to develop a pipeline model filled by brackish water and heavy oil, the main components present in oil wells the Northeast, and heating it using microwaves to reduce its viscosity. This process is intended to prevent the extraction system is blocked by paraffin buildup. Five models were developed for the realization of studies heating by electromagnetic radiation and potential were varied in three steps. The simulations were all developed using multifísico software COMSOL. The simulation results are plotted in graphs in one and two dimensions, in order to compare the performance of each model used to describe the energy conversion efficiency in the system and analyzing the propagation and absorption of electromagnetic radiation in the dielectric / Com a crescente demanda dos produtos derivados do petróleo, surge a necessidade de buscar cada vez mais novas técnicas de extração que aumente a produção de barris com o menor custo possível. Com isso, surge também a preocupação com o meio ambiente e todo o eco sistema próximo aos campos de extração. Técnicas para aumentar o fator de recuperação desses poços vem sendo desenvolvidas e aperfeiçoadas ao longo dos últimos anos. O método de aquecimento por micro-ondas é um processo onde a energia eletromagnética em alta frequência é transformada em energia térmica por perdas dielétricas e/ou absorção eletromagnética. As pesquisas usando como base as técnicas de aumento do fator de recuperação por aquecimento eletromagnético ainda são pouco desenvolvidas. O intuito do presente trabalho é o de desenvolver um modelo de duto totalmente preenchido por água salobra e óleo pesado, principais componentes presentes em poços de petróleo da região nordeste, e aquecer o mesmo usando micro-ondas para diminuir sua viscosidade. Esse processo tem por finalidade evitar que o sistema de extração seja obstruído por acúmulo de parafina. Cinco modelos foram desenvolvidos para a realização dos estudos de aquecimento por radiação eletromagnética e as potencias foram variadas em três etapas. As simulações foram todas desenvolvidas usando o software multifísico COMSOL. Os resultados das simulações foram plotados em gráficos em uma e duas dimensões, com o intuito de comparar o desempenho de cada modelo adotado, descrever a eficiência de conversão de energia no sistema e analisar a propagação e absorção da radiação eletromagnética no dielétrico / 2017-05-23