<p>The carbon metabolism in costal sediments is of major importance for the global carbon cycle. Costal sediments are also subjected to physical forcing generating water fluxes above and through the sediments, but how the physical affect the carbon metabolism is currently poorly known. In this study, the effect of advective pore water flow on degradation of organic matter in permeable sandy sediment was investigated in a laboratory study during wintertime. Sediments were collected from both brackish water (Askö) and from a fresh water stream (Getå Stream). In two chamber experiments, with and without advective pore water flow, the degradation of organic matter was measured through carbon dioxide analysis from water and headspace. In Askö sediments mineralization rates ranged from 3.019 - 5.115 mmol C m-2 d-1 and 3.139 mmol C m-2 d-1 with and without advective pore water flow, respectively. Those results correspond with results from earlier studies of carbon mineralization rates in sediment in the North Sea and the Baltic Sea. There were no significant differences between the two groups in the Askö sediment. In Getå Stream sediments mineralization rates ranged between 4.059 mmol C m-2 d-1 and 6.806 mmol C m-2 d-1 with and without advective flow, respectively. The mineralization rates for Getå Stream correspond with earlier studies of carbon mineralization rates in a stream in New Hampshire.</p>

The carbon metabolism in costal sediments is of major importance for the global carbon cycle. Costal sediments are also subjected to physical forcing generating water fluxes above and through the sediments, but how the physical affect the carbon metabolism is currently poorly known. In this study, the effect of advective pore water flow on degradation of organic matter in permeable sandy sediment was investigated in a laboratory study during wintertime. Sediments were collected from both brackish water (Askö) and from a fresh water stream (Getå Stream). In two chamber experiments, with and without advective pore water flow, the degradation of organic matter was measured through carbon dioxide analysis from water and headspace. In Askö sediments mineralization rates ranged from 3.019 - 5.115 mmol C m-2 d-1 and 3.139 mmol C m-2 d-1 with and without advective pore water flow, respectively. Those results correspond with results from earlier studies of carbon mineralization rates in sediment in the North Sea and the Baltic Sea. There were no significant differences between the two groups in the Askö sediment. In Getå Stream sediments mineralization rates ranged between 4.059 mmol C m-2 d-1 and 6.806 mmol C m-2 d-1 with and without advective flow, respectively. The mineralization rates for Getå Stream correspond with earlier studies of carbon mineralization rates in a stream in New Hampshire.

Submitted by Maria Medeiros (maria.dilva1@ufcg.edu.br) on 2018-10-18T12:30:31Z No. of bitstreams: 1 ADEMIR MORAIS DE MEDEIROS - DISSERTAÇÃO (PPGEQ) 2017.pdf: 3204134 bytes, checksum: c8135684c13cdcbef03ebfe63c7a1c99 (MD5) / Made available in DSpace on 2018-10-18T12:30:31Z (GMT). No. of bitstreams: 1 ADEMIR MORAIS DE MEDEIROS - DISSERTAÇÃO (PPGEQ) 2017.pdf: 3204134 bytes, checksum: c8135684c13cdcbef03ebfe63c7a1c99 (MD5) Previous issue date: 2017-10-30 / Capes / A dessalinização é um processo bastante difundido e utilizado no mundo para o tratamento de águas de diversas fontes hídricas as quais necessitam de tratamento para tornar-se potável e assim promover a segurança hídrica e a manutenção da vida, embora pouco utilizada na proporção necessária, a dessalinização de águas no Nordeste Brasileiro vem se tornando uma técnica bastante requisitada devido sua eficiência no tratamento de águas. O objetivo desta pesquisa foi avaliar a qualidade do permeado de um sistema hibrido de membranas para fins de dessalinização de águas salobras com a remoção do gás carbônico por uma torre de resfriamento, avaliando o desempenho do processo de separação por membrana para tratamento de águas através de estudo avaliativo dos dados reais com os simulados ambos para o permeado da OI. Os dados teóricos são os resultados obtidos a partir de análises reais realizadas nas águas do presente trabalho, inseridos no SOFWARE ROSA® 8.0.3 e realizada as simulações. No presente trabalho utilizou-se a membrana polimérica de Osmose Inversa (BW30 4040) na simulação e nos experimentos de bancadas. A partir da simulação foi possível ajustar as pressões de operação para os seguintes valores: 6, 9, 11, e 13 bar, para água de superfície e 13 e 15 bar para água de poço. Avaliou-se a rejeição de sais (%RS) obtendo valores próximos de 98 % para o permeado. Estudou-se por meio de uma torre de resfriamento como um pós-tratamento, a remoção de CO2 que apresentou como efeito, a diminuição do pH do permeado. Verificou-se através de análises que após a torre de ocorreu uma remoção parcial média de dióxido de carbono de cerca 75 %. / Desalination is a widely used process in the world for the treatment of water from a variety of water sources, which requires treatment to become potable and thus promote water safety and life-support, although little used in the necessary proportion, to desalination of water in the Brazilian Northeast has become a highly requested technique due to its efficiency in water treatment. The objective of this research was to evaluate the permeate quality of a hybrid membrane system for desalination of brackish water with the removal of carbon dioxide by a cooling tower, evaluating the performance of the membrane separation process for water treatment through evaluation of the real data with the simulated ones for the RO permeate. Theoretical data are the results obtained from real analyzes performed in the waters of the present work, inserted in SOFWARE ROSA® 8.0.3 and the simulations were performed. In the present work the polymer membrane of Reverse Osmosis (BW304040) was used in the simulation and bench experiments. From the simulation it was possible to adjust the operating pressures to the following values: 6 bar 9 bar, 11bar, and 13 bar for surface water and 13 bar and 15 bar for well water. The salt rejection (% SR) was evaluated, obtaining values close to 98% for the permeate. It was studied by means of a cooling tower as a post-treatment, the removal of CO2 that had as effect, the decrease of the pH of the permeate. It was verified through analyzes that after the tower a mean partial removal of carbon dioxide of about 75% occurred.

Submitted by Edileide Reis (leyde-landy@hotmail.com) on 2013-04-23T12:03:04Z No. of bitstreams: 1 Joilma Menezes.pdf: 1646474 bytes, checksum: 55d6d57db450f3ab1ef86b3ac1a50087 (MD5) / Made available in DSpace on 2013-04-23T12:03:04Z (GMT). No. of bitstreams: 1 Joilma Menezes.pdf: 1646474 bytes, checksum: 55d6d57db450f3ab1ef86b3ac1a50087 (MD5) Previous issue date: 2009 / Para tornar potáveis águas salobras ou salinas, é necessário fazer a dessalinização, processo que normalmente exige alto investimento e recursos tecnológicos complexos para a produção em larga escala. Neste caso, o preço da água para o consumidor final torna-se muito mais elevado, devido à menor oferta e gastos envolvidos. O objetivo geral desse trabalho foi desenvolver um dispositivo caseiro para dessalinização de pequenas quantidades de água para o uso em dessedentação humana para aplicação em regiões com água de salinidade inadequada para beber, utilizando material biológico, como sementes de espécies de plantas do Semi-Árido baiano ou com possível cultivo naquela região. A metodologia empregada no trabalho foi baseada na medida da salinidade da água antes e após o contato com o material biológico. Dez tipos diferentes de sementes foram estudados: Amendoa (Terminalia Catappa L.), Umbu (Spondndias Tuberosa Cheg. Cam.), Moringa (Moringa Oleifera Lam), Mulungu (Erythrina verna Vell), Umburana (Erythrina verna Vell), Bucha Vegetal (Luffa Cylindrica), Algaroba (Prosopis juliflora), Abobora (Cucúrbita Pepo L., ), Girassol (Helianthus Annus), e Mesocarpo e Endocarpo do Coco (Cocos Nucifera) e para os experimentos utilizou-se água de salinidade 0,7o/oo (baixa salobridade de ocorrência freqüentemente no semi-árido baiano). Após o contato da água salobra com o material biológico determinava-se a concentração de sódio remanescente na água, representando o NaCl, não sorvido pelo material biológico, principal sal responsável pela salinidade da água. Para análise de sódio foi usado a técnica analítica da fotometria de chama (Micronal, Mod. B462). Na escolha final do sorvente a ser usado no dispositivo caseiro foi considerado prioritário, além da maior capacidade de sorção de sais, menor teor de sal intrínseco e abundância na região semi-árida e/ou com possibilidade de adaptação para cultivo naquela região. A semente de umbu (Spondndias Tuberosa Cheg. Cam.) apresentou maior capacidade de sorção de sais da água salobra, principalmente quando seca a 250º C, por 1 hora. Dessa forma desenvolveu-se um dispositivo caseiro para dessalinização de água, em pequenas quantidades, suficientes para o uso familiar em dessedentação humana, a partir desta semente tratada segundo indicação neste trabalho, podendo transformar água de baixa salobridade, mas imprópria para beber (> 0,5 a 1,5 o/oo) em água doce e baixar a alta dureza de águas a níveis de aceitação para consumo humano. O estudo da adsorção dos sais em umbu realizado para explicar o processo de dessalinização da água salobra usando-se material produzido por secagem e moagem da semente do umbu, atendeu ao modelo de Langmuir e permitiu estimar a capacidade máxima de adsorção de sódio pelo umbu a 30, 40 e 50°C em: 52,6, 165 e 250 mg g-1 respectivamente. Desta forma, 1 L de água salobra de salinidade entre 0,6 e como aquelas do Semi Árido baiano testadas, pode ter seu teor de sal removido com apenas 1g daquelas sementes tratadas segundo indicação neste trabalho e aquecendo a água a 50°C. / Salvador

Fresh water in Kuwait is produced by non- conventional methods. About 95% of this water comes from desalinated seawater using multi-stage flash distillation technique and the remainder comes from underground brackish water. The blended water containes organic, inorganic and trace metal impurities within the recommended international standard limits. The purpose of this work is to identify the source of selected trace metals present in the drinking water in Kuwait. Chromium, copper, iron, lead, manganese, nickel, vanadium and zinc have been analysed using atomic absorption spectroscopy (AAS) and inductively coupled plasma mass spectroscopy (ICPMS). Efforts were made to improve the preconcentration of the selected metals and their separation from the high concentration of salts in seawater which affect the accuracy and cause major interference in the analysis. Solid-liquid extraction (chelex-100 resin) and liquid-liquid extraction (methyl iso-butyl ketone and freon) with and without back-extraction into nitric acid were investigated. Liquid-liquid extraction without back-extraction proved to give optimum recovery of the selected metals. Results confirmed that both AAS and ICP-MS are suitable for the analysis of trace metals in Kuwait's waters. Although AAS technique proved to be more accurate in analysing the selected metals than ICP-MS, the latter was adopted since its accuracy is acceptable (1.1-4.4%) and it is easier and faster than the former technique. The study revealed that the source of copper, iron, nickel and zinc is the construction materials of the distillation plants, while the source of lead and vanadium is the brackish water. Manganese and chromium concentrations are very low in all sources. No direct relationship between the metal concentration in the seawater and the distillate could be deduced.

Yes / The implementation of Reverse Osmosis (RO) technology is noticeably increased to produce freshwater from brackish and seawater resources. In this work, performance analysis of a multistage multi pass medium-sized spiral wound brackish water RO (BWRO) desalination plant (1200 m³/day) of Arab Potash Company (APC) located in Jordan is evaluated using modelling and simulation. For this purpose, a mathematical model for the spiral wound RO process based on the principles of solution diffusion model is developed. The model is then used to simulate the operating conditions of low-salinity brackish water RO (BWRO) desalination plant. The results obtained are then compared against the real industrial data of BWRO desalination plant of APC which shows a high-level of consistency. Finally, the model is used to analysis the impact of the operating parameters such as salinity, pressure, temperature, and flow rate on the plant performance. The sensitivity analysis confirms that both feed flow rate and operating pressure as the critical parameters that positively affect the product salinity.

Yes / The Reverse Osmosis (RO) input parameters have key roles in mass transport and performance indicators. Several studies can be found in open literature. However, an experimental research on evaluating the brackish water RO input parameters influence on the performance metrics with justifying the interference between them via a robust model has not been addressed yet. This paper aims to design, construct, and experimentally evaluate the performance of a 50 m3/d RO pilot-plant to desalinate brackish water in Shahid Chamran University of Ahvaz, Iran. Water samples with various salinity ranging from 1000 to 5000 ppm were fed to a semi-permeable membrane under variable operating pressures from 5 to 13 bar. By evaluating permeate flux and brine flowrate, permeate and brine salinities, membrane water recovery, and salt rejection, some logical relations were derived. The results indicated that the performance of an RO unit is largely dependent on feed pressure and feed salinity. At a fixed feed concentration, an almost linear relationship was found to relate feed pressure and both permeate and brine flowrates. Statistically, it was found that 13 bar feed pressure results in a maximum salt rejection of 98.8% at a minimum permeate concentration of 12 ppm. Moreover, 73.3% reduction in permeate salinity and 30.8% increase in brine salinity are reported when feed pressure increases from 5 to 13 bar. Finally, it is concluded that the water transport coefficient is a function of feed pressure, salinity, and temperature, which is experimentally estimated to be 2.8552 L/(m2 h bar).

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.