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Kommunalförbundet Norrvatten är en av Sveriges största producenter av dricksvatten och förser över 50 miljoner vatten till över 700 000 invånare i norra Stockholm. Vattnet är renat i Görvälnverket som har sedan år 2016 planlagt en expansion av verkets kapacitet och kvalité. Ett fokusområde för att förbättra reningsprocessen är implementering av membranteknik. I det här projektet har experiment utförts som ett fortsatt arbete av att integrera ultrafiltration med koagulering på en mikropilot. Syftet med projektet är att optimera driftparameterar (koaguleringsdos, pH och alkalitet, uppehållstid och omblandning) för processen och jämföra pilotens effektivitet för två typer av matarvatten (kol- och sandfiltrat). En lägre koaguleringsdos på 2.5 mg Al/L resulterade i en 18.9 % avskiljning av TOC och 21.3% minskning i UV254. I jämförelse med en högre dos på 3.8 mg Al/L, var effektiviteten 2 % bättre för TOC och 3 % bättre för UV254. Till följd av en låg ökning i effektivitet för en högre koagulantdos påvisar en lägre dosering ett bättre alternativ. Dessutom är det rekommenderat att vid uppskalandet av piloten mer försök genomförs för att få mer pålitliga data och att automatisk dosering implementeras eftersom dosering av koagulant var en svårkontrollerad parameter.pH inom intervallet 6.8 till 7.2 visade vara mest optimal för att minimera mängden aluminiumrester i permeatet. Experimenten på pH konstaterar att flockning är pH beroende och optimalt vid pH 7. Effektiviteten var också beroende av alkaliteten. Där bäst alkalinitet anpassades till mellan 40 och 50 mg HCO3/L, med högre än 50 mg HCO3/L minskade effektiviteten av avskiljningen, vilket tyder på sämre flockning vid basiska förhållanden. Karbonatdosering av 5 mL 0.01 M Na2CO3 /L obehandlat vatten uppnådde önskad alkalinitet och minimerade aluminiumrester i permeatet.  Uppehållstiden och konfigurationen av blandning indikerade ingen optimal justering. Emellertid, en jämförelse av försök med uppehållstiden och försök utan koaguleringdos visade dramatisk minskning i effektivitet till endast 2 % TOC avskiljning och 6 % UV254 minskning. Placering av ultrafiltrationsenheten efter kolfiltret jämfört med efter sandfiltret visade inga tecken på nedsatt effektivitet. Transmembrantrycket över membranet ökade över den experimenterade perioden från 0.02 till 0.06 bar och fluktuerade under drift mellan det första och sista försöket. Det var däremot ingen skillnad i trycket mellan kolfilter och sandfilter, vilket styrker beslutet att placera ultrafiltrationsenheten efter kolfiltret. / The municipal association Norrvatten is one of Sweden's largest drinking water producers and distributes over 50 million m3 of drinking water to around 700 000 inhabitants in northern Stockholm. The water is treated in the Görväln plant, which has since 2016 planned to expand its capacity and improve its water quality. One researched area for improving the treatment process is implementing membrane technology. In this project, experiments are performed as a continued work of integrating ultrafiltration with coagulation on a bench-scale plant. The purpose is to optimise the operating parameters (coagulant dosage, pH & alkalinity, retention time, and mixing) and compare the ultrafiltration removal efficiency for two types of feed water (carbon and sand filtrate).  A lower coagulant dosage of 2.5 mg Al/L resulted in removal efficiencies on average of 18.9 % TOC removal and 21.3 % UV254 reduction. Compared to the higher dosage of 3.8 mg Al/L, the removal efficiency was only decreased with 2 % TOC and 3 % UV254. Therefore, a lower dosage is a more suitable option. Although, more data needs to be collected for a more reliable optimal dosage. In addition, for the up-scaling of the pilot, automatic dosage control needs to be implemented as the coagulant dosage is difficult to control as a parameter. pH showed the best removal efficiency in the range of 6.8 to 7.2 and minimised aluminium residue in the permeate. It verifies that flock formation is pH-dependent and optimal close to 7. The efficiency also depended on the alkalinity, with the optimal alkalinity between 40 to 50 mg HCO3/L. Higher alkalinity decreased the efficiency, which supports the theory that too basic water hinders flock formation. With minimum dosage of 5 mL 0.01 M Na2CO3/L untreated water, the required alkalinity could be achieved without affecting the amount of aluminium in the permeate residue.  The retention time and mixing configuration did not result in an optimum adjustment. However, with no retention time at a coagulant dosage of 0 mg Al/mL, the efficiency was reduced drastically to 2 % TOC removal and 6 % UV254 reduction. The placement after the carbon filter showed no adverse signs on the removal efficiency compared with placing it after the sand filter. The TMP of the membrane increased over time from 0.02 to 0.06 bar, and higher fluctuations in TMP were noted in the last experiment compared to the first. The differences were identical for both carbon and sand filtrate, strengthening the decision to place the ultrafiltration unit after the carbon filter.

Modelos matemáticos são representações ou interpretações simplificadas da realidade ou uma representação de um fragmento de um sistema. As simulações destes fenômenos auxiliam na tomada de decisão da parte interessada, ou seja, aqueles que trabalham em uma área. A modelagem de um sistema de processos anaeróbios, como o tratamento de um efluente em reatores UASB (Upflow Anaerobic Sludge Blanket), auxilia os gestores destes sistemas na operação e no controle de estabilidade. O modelo ADM1 (Anaerobic Digestion Model Nº 1), criado pela IWA em 2002, simula o comportamento da digestão anaeróbia. Entretanto, este modelo não considera a hidrodinâmica do sistema como fator relevante no desempenho do processo. O estudo do comportamento do escoamento de efluente no interior de um reator é possível através de ensaios de hidrodinâmica. Estes são conduzidos, majoritariamente, por meio de experimentos laboratoriais que se utilizam de traçadores que, por sua vez, podem resultar em custos elevados. A Dinâmica de Fluidos Computacional (DFC) é uma área na mecânica dos fluidos que utiliza análises numéricas e algoritmos para solucionar e analisar problemas relacionados com escoamento de fluidos. Os softwares de DFC que resolvem estes algoritmos podem ser utilizados na simulação dos ensaios de hidrodinâmica. Foi utilizado nesta tese o pacote de DFC Ansys®, em que o software CFXTM foi o escolhido para realizar as simulações de escoamento. Um dos objetivos desta tese foi a validação desta simulação por meio de ensaios de laboratório e ensaios virtuais em um reator UASB em escala de bancada (1,5 L). Resultou-se, dessa comparação, em dados estatisticamente similares (teste U de Mann-Whitney), proporcionando validação do método. Após esta validação, simulou-se o mesmo tipo de ensaio para um reator UASB em formato de \"Y\" (escala piloto; 119,3 L). Foram simuladas três condições operacionais, em que se variou a vazão de alimentação, sendo esta função da carga orgânica volumétrica aplicada ao lodo (COV). As COV foram 7,5, 12,5 e 17,5 kgDQO m-3d-1. Obteve-se N-CSTR (número de reatores de mistura completa em série) igual a 11, 10 e 10 unidades para cada condição, respectivamente. A ferramenta de Dinâmica de Sistemas utiliza-se de uma abordagem de entendimento de modelos complexos e, por meio de ciclos de retroalimentação (feedback) e estoques e fluxos (stocks and flows), demonstra que modelos aparentemente simples podem ser muito complexos. Existem vários softwares de Dinâmica de Sistemas e neles podem ser implementados os mais variados modelos. Utilizando o software Vensim PLE®, modelou-se a digestão anaeróbia do ácido acético por meio de equações baseadas no modelo de cinética enzimática de Monod e no modelo de digestão anaeróbia ADM1. Considerou-se as taxas de consumo de substrato e crescimento de biomassa bacteriana, a inibição causada pelo pH e a quantidade de alcalinizante necessária para atingir o pH desejado deste meio. De forma complementar, integrou-se um modelo de cálculo de alcalinidade do meio e, desta forma, foi possível determinar as concentrações de cada espécie que confere alcalinidade ao meio, considerando o equilíbrio do carbonato. Denominou-se esta modelação (DFC e dinâmica de sistemas) de Modelo Hidro-bioquímico do processamento anaeróbio. Os resultados obtidos por Del Nery et al. (2016) corroboraram com os obtidos nesta tese. / Mathematical models are representations and simplified interpretations of reality or a representation of a system fragment. The modeling of anaerobic processes, such as wastewater treatment in UASB (Upflow Anaerobic Sludge Blanket) reactors, helps managers in the operation of these systems and stability control. The Anaerobic Digestion Model No. 1 (ADM1), created by IWA in 2002, simulates the behavior of anaerobic digestion. However, this model does not consider the system hydrodynamics as a relevant factor in the performance of the process. The effluent flow behavior studies on the reactor inside is possible by hydrodynamic tests. These are conducted through laboratory experiments that uses tracers and this can result in high costs in the conduct of the tests. The Computational Fluid Dynamics (CFD) is an area in fluid mechanics that uses numerical analysis and algorithms to solve and analyze problems related to fluid flow. CFD software can be used to simulate the hydrodynamics assays. It was used in this thesis Ansys® workbench, wherein the CFXTM software was chosen to perform CFD flow simulations. One objective of this thesis was to validate the CFD simulation through laboratory and virtual testing in a UASB bench scale (1.5 liters). In this comparison, it resulted in similar data statistically (Mann-Whitney U test). After validation of the hydrodynamic test, was simulated the same type of assay for an UASB reactor \"Y\" shaped (pilot scale; = 82.27 liters working volume). The test result was N-CSTR (number of complete mixing reactors in series) equal to 4 units, considering a 103.9 liters per day of feed flow (hydraulic retention time of 19 hours). The system dynamics tool makes use of understanding approach of complex models and, through feedback loops and stocks and flows, shows that seemingly simple models can be very complex. There are several system dynamics software and most varied models can be implemented. Using Vensim PLE® software, it was developed an acetate anaerobic digestion model (in this case acetic acid) via equations based on the Monod and ADM1 model. It was considered for the hydro-biochemical modeling, substrate consumption and growth of bacterial biomass rates, the pH inhibition and the amount of alkalizing necessary to achieve the desired pH of the medium. Complementarily, integrated into a calculation alkalinity model of the medium and thus it was possible to determine the concentrations of each species imparts environment alkalinity, considering the carbonate balance.

Neste trabalho avaliou-se o desempenho de um reator anaeróbio operado em batelada seqüencial e contendo biomassa imobilizada (ASBBR) em espuma de poliuretano quando submetido a diferentes tempos de alimentação e cargas orgânicas volumétricas, além da aplicação de cargas de choque orgânicas. O reator, com mistura por recirculação da fase líquida e mantido à 30 ± 1 ºC, tratou soro de queijo reconstituído e possuiu 2,5 L de volume reacional. Os resultados mostraram que o tempo de alimentação utilizado exerceu maior influência sobre o desempenho do reator para maiores valores de carga orgânica volumétrica. Durante a operação com carga orgânica volumétrica de 3 gDQO/L.d, a alteração do tempo de alimentação não influenciou na eficiência de remoção de matéria orgânica filtrada, que foi de 98%. Sob carregamento orgânico volumétrico de 6 gDQO/L.d, verificou-se tendência de queda daquela variável para maiores tempos de enchimento: 99, 98 e 97%, para tempos de alimentação de 2, 4 e 6 horas, respectivamente. Na operação com carga orgânica volumétrica de 12 gDQO/L.d, o aumento do tempo de alimentação resultou em queda mais significativa da eficiência de remoção de matéria orgânica filtrada: 97, 95 e 93%, para tempos de alimentação de 2, 4 e 6 horas, respectivamente. Em todas as condições, a aplicação de cargas de choque de 24 gDQO/L.d causaram o aumento da concentração de ácidos no efluente. No entanto, apesar desse aumento, o reator retomou rapidamente sua estabilidade, sendo a alcalinidade otimizada ao afluente suficiente para manter o pH próximo do neutro durante toda a operação. Independente da carga orgânica volumétrica aplicada, a operação com tempo de alimentação de 2 horas foi aquela que proporcionou maior estabilidade e menor suscetibilidade do processo às cargas de choque orgânicas. / This work assessed the performance of an anaerobic sequencing batch reactor containing immobilized biomass (ASBBR) on polyurethane foam when submitted to different feeding times, volumetric loading rate and organic shock loads. The reactor, in which mixing occurred by recirculating the liquid phase, contained 2,5 L reaction medium and was maintained at 30 ± 1 ºC for treating reconstituted cheese whey. Results showed that the effect of feeding time on reactor performance was more pronounced at higher volumetric loading rates. During operation at volumetric loading rate of 3 gDQO/L.d, changing feeding time did not affect filtered organic matter removal efficiency, which amounted to 98%. At volumetric loading rate of 6 gDQO/L.d, removal efficiency showed a tendency to drop at higher feeding times: 99, 98 and 97%, for feeding times of 2, 4 and 6 hours, respectively. At volumetric loading rate of 12 gDQO/L.d, increase in feeding time resulted in a more significant drop in filtered organic matter removal efficiency: 97, 95 and 93%, for feeding times of 2, 4 and 6 hours, respectively. Application of shock loads of 24 gDQO/L.d caused increase in acids concentration in the effluent, at all conditions. However, despite this increase, the reactor readily regained stability and optimized alkalinity supplementation to the influent was sufficient to maintain near neutral pH during the entire operation. Regardless of applied volumetric loading, operation with feeding time of 2 hours was which yielded maximum stability and reduced susceptibility of the process to organic shock loads.

Modelos matemáticos são representações ou interpretações simplificadas da realidade ou uma representação de um fragmento de um sistema. As simulações destes fenômenos auxiliam na tomada de decisão da parte interessada, ou seja, aqueles que trabalham em uma área. A modelagem de um sistema de processos anaeróbios, como o tratamento de um efluente em reatores UASB (Upflow Anaerobic Sludge Blanket), auxilia os gestores destes sistemas na operação e no controle de estabilidade. O modelo ADM1 (Anaerobic Digestion Model Nº 1), criado pela IWA em 2002, simula o comportamento da digestão anaeróbia. Entretanto, este modelo não considera a hidrodinâmica do sistema como fator relevante no desempenho do processo. O estudo do comportamento do escoamento de efluente no interior de um reator é possível através de ensaios de hidrodinâmica. Estes são conduzidos, majoritariamente, por meio de experimentos laboratoriais que se utilizam de traçadores que, por sua vez, podem resultar em custos elevados. A Dinâmica de Fluidos Computacional (DFC) é uma área na mecânica dos fluidos que utiliza análises numéricas e algoritmos para solucionar e analisar problemas relacionados com escoamento de fluidos. Os softwares de DFC que resolvem estes algoritmos podem ser utilizados na simulação dos ensaios de hidrodinâmica. Foi utilizado nesta tese o pacote de DFC Ansys®, em que o software CFXTM foi o escolhido para realizar as simulações de escoamento. Um dos objetivos desta tese foi a validação desta simulação por meio de ensaios de laboratório e ensaios virtuais em um reator UASB em escala de bancada (1,5 L). Resultou-se, dessa comparação, em dados estatisticamente similares (teste U de Mann-Whitney), proporcionando validação do método. Após esta validação, simulou-se o mesmo tipo de ensaio para um reator UASB em formato de \"Y\" (escala piloto; 119,3 L). Foram simuladas três condições operacionais, em que se variou a vazão de alimentação, sendo esta função da carga orgânica volumétrica aplicada ao lodo (COV). As COV foram 7,5, 12,5 e 17,5 kgDQO m-3d-1. Obteve-se N-CSTR (número de reatores de mistura completa em série) igual a 11, 10 e 10 unidades para cada condição, respectivamente. A ferramenta de Dinâmica de Sistemas utiliza-se de uma abordagem de entendimento de modelos complexos e, por meio de ciclos de retroalimentação (feedback) e estoques e fluxos (stocks and flows), demonstra que modelos aparentemente simples podem ser muito complexos. Existem vários softwares de Dinâmica de Sistemas e neles podem ser implementados os mais variados modelos. Utilizando o software Vensim PLE®, modelou-se a digestão anaeróbia do ácido acético por meio de equações baseadas no modelo de cinética enzimática de Monod e no modelo de digestão anaeróbia ADM1. Considerou-se as taxas de consumo de substrato e crescimento de biomassa bacteriana, a inibição causada pelo pH e a quantidade de alcalinizante necessária para atingir o pH desejado deste meio. De forma complementar, integrou-se um modelo de cálculo de alcalinidade do meio e, desta forma, foi possível determinar as concentrações de cada espécie que confere alcalinidade ao meio, considerando o equilíbrio do carbonato. Denominou-se esta modelação (DFC e dinâmica de sistemas) de Modelo Hidro-bioquímico do processamento anaeróbio. Os resultados obtidos por Del Nery et al. (2016) corroboraram com os obtidos nesta tese. / Mathematical models are representations and simplified interpretations of reality or a representation of a system fragment. The modeling of anaerobic processes, such as wastewater treatment in UASB (Upflow Anaerobic Sludge Blanket) reactors, helps managers in the operation of these systems and stability control. The Anaerobic Digestion Model No. 1 (ADM1), created by IWA in 2002, simulates the behavior of anaerobic digestion. However, this model does not consider the system hydrodynamics as a relevant factor in the performance of the process. The effluent flow behavior studies on the reactor inside is possible by hydrodynamic tests. These are conducted through laboratory experiments that uses tracers and this can result in high costs in the conduct of the tests. The Computational Fluid Dynamics (CFD) is an area in fluid mechanics that uses numerical analysis and algorithms to solve and analyze problems related to fluid flow. CFD software can be used to simulate the hydrodynamics assays. It was used in this thesis Ansys® workbench, wherein the CFXTM software was chosen to perform CFD flow simulations. One objective of this thesis was to validate the CFD simulation through laboratory and virtual testing in a UASB bench scale (1.5 liters). In this comparison, it resulted in similar data statistically (Mann-Whitney U test). After validation of the hydrodynamic test, was simulated the same type of assay for an UASB reactor \"Y\" shaped (pilot scale; = 82.27 liters working volume). The test result was N-CSTR (number of complete mixing reactors in series) equal to 4 units, considering a 103.9 liters per day of feed flow (hydraulic retention time of 19 hours). The system dynamics tool makes use of understanding approach of complex models and, through feedback loops and stocks and flows, shows that seemingly simple models can be very complex. There are several system dynamics software and most varied models can be implemented. Using Vensim PLE® software, it was developed an acetate anaerobic digestion model (in this case acetic acid) via equations based on the Monod and ADM1 model. It was considered for the hydro-biochemical modeling, substrate consumption and growth of bacterial biomass rates, the pH inhibition and the amount of alkalizing necessary to achieve the desired pH of the medium. Complementarily, integrated into a calculation alkalinity model of the medium and thus it was possible to determine the concentrations of each species imparts environment alkalinity, considering the carbonate balance.

Wood ash application (WAA) has been recommended mainly for two reasons; i) to avoid depletion of minerals in the soil due to whole tree harvest in the forestry and ii) to mitigate harmful effects of acidification of soil and surface waters. In conclusion, the effects on terrestrial ecosystems and, especially, tree growth, can be attributed to the properties of the ash, the dose applied and the specific site at which the ash is applied. The research conducted on the effects of WAA on limnological ecosystems is very limited, and the major purpose of the present thesis was to gain knowledge of the effects of wood ash to different freshwater organisms, and the more comprehensive, limnological effects of WAA in the first stream in Bispgården, Sweden. Effects of wood ash solutions on the unicellular alga Euglena gracilis Klebs, the amphipod Gammarus pulex L., and the moss Fontinalis antipyretica Hedw. were investigated under laboratory conditions. Common in all three species was the decline in performance (growth/velocity/respiration/oxygen evolution) when the concentration of wood ash exceeded 5 g/l and no adjustment of pH was done (alkaline solution). In contrast, different movement parameters (motility, upwards swimming and velocity) in E. gracilis (neutral conditions), and increased growth of F. antipyretica with increased concentrations of wood ash indicated that nutrients in the ash was bioavailable for these organisms. There was no evidence of toxic effects on the organisms from metals or other compounds as a result from exposure to wood ash solutions in the present studies. The field study was conducted in a forest area close to Bispgården, about 100 km NW from Sundsvall, Sweden. The catchment area (50 ha) of the stream Fanbergsbäcken was treated with wood ash in September of 2004 (3,000 kg/ha;selfhardened crush-ash). In general, both biological (diatoms) and chemical (pH, alkalinity, and aluminum (Al) measurements) indicators have shown no significant effect on acidification parameters from the addition of wood ash. There was, however, evidence of an increased pH during spring flood, accompanied with a decrease in the frequency of low pH values (<5.6) during spring flood. In addition to this, alkalinity was significantly higher in the period 2005-2006, compared to that of 2003. High concentrations of toxic forms of Al repeatedly occured in the stream Fanbergsbäcken, and the WAA did not affect the frequencies of high concentrations of toxic Al forms (<50 μg/l). Both the moss F. antipyretica and the leaves from Alnus incana displayed increased potassium (K) concentrations, although other nutrients did not increase from WAA. In conclusion, no evidence of WAA being effective in restoring or improving the ecological status of freshwater environments has been established, either in the literature or in the present field study. On the other hand, there were no indications of harmful effects due to WAA, either. However, we still do not know the effects of wood ash on several organisms (predominantly invertebrates) inhabiting small ponds and other, temporary or permanent, freshwater ecosystems. In the context of WAA, these environments and organisms have not attended any attention in the research published to date, and future studies are strongly encouraged.

Ocean uptake of anthropogenic CO2 causes ocean acidification, a secular, global-scale decline in the pH of seawater. In order to better understand the implications of contemporary acidification for marine organisms and ecosystems, there is a need to better characterise natural variability in carbonate chemistry. In this thesis, climatological seasonal variability of sea surface pH and aragonite saturation state (OmegaA) in the open ocean is indirectly derived from other parameters of the marine CO2 system, namely total alkalinity (TA) and seawater pCO2/fCO2 (pCO2sw/fCO2sw). New monthly sea surface TA, fCO2sw and temperature climatologies are developed for this purpose, utilising newly-released observational synthesis products (PACIFICA for TA and SOCAT v2 for fCO2sw). Two versions of the new SST climatology are developed, referred to as upper and lower SST (USST and LSST), to test sensitivity to the depth range of the input observations. Annual ranges are generally found to be larger for the USST climatology, derived using observations from the upper 2 m, compared to LSST (which is based on deeper observations). Further, a seasonal cycle is found in the monthly average of the differences between these climatologies north of 30 degN, perhaps partly due to seasonal variation in near-surface stratification. The USST seasonal ranges are also found to be generally larger than in two previous SST climatologies, however, difference in the depth distribution of the input measurements is unlikely the main cause. The new monthly sea surface TA climatology extends coverage into the Nordic seas, excluded from previous climatologies. TA seasonality is found to be small outside of regions with large seasonal ranges in salinity. Large seasonal ranges in salinity and TA are found beneath the Intertropical Convergence Zone, in the Antarctic seasonal sea ice zone and in the western Greenland Sea. Non-salinity driven TA seasonality is found to be large in the Gulf of Alaska, eastern equatorial Pacific and western Greenland Sea. Compared to the Lee et al. (2006) TA climatology, substantially lower annual means and seasonal ranges are found for the subarctic Pacific, a region with greatly improved coverage courtesy of PACIFICA. The pH/OmegaA climatologies derived in the final chapter suggest pH seasonality is predominantly temperature driven in the subtropics and mainly driven by variation in salinity normalised dissolved inorganic carbon (sDIC) in the subpolar north Atlantic, western subarctic Pacific and Southern Ocean. Salinity variation is found to only exert a strong influence on pH seasonality in the western Greenland Sea. Climatological seasonal pH ranges are found to be mostly small in the tropics (<0.05), moderate in the subtropics (0.05-0.10) but very large (>0.1) in parts of the Ross, Weddell, Irminger and Iceland Seas and western subarctic Pacific gyre. OmegaA seasonality is found to be predominantly sDIC-driven everywhere except in the western Greenland Sea, with temperature variation generally being of modest influence. Seasonal cycles of pH and OmegaA are found to be in anti-phase where pH is mainly thermally driven and in-phase where pH is mainly sDIC-forced (both pH and OmegaA vary inversely with DIC). Comparison is made between the primary new pH/OmegaA climatology and various open ocean carbonate chemistry time-series. The climatology captures the general form of the climatological seasonal cycles of pH and OmegaA from the time-series, although with some differences in phasing and seasonal range. Analysing the time-series for long-term trends, I find that inter-decadal anthropogenic CO2 uptake driven pH and OmegaA declines can be modulated by trends in temperature, salinity or sTA. Investigation is also conducted into how the amplitude of pH and OmegaA seasonal cycles might change by 2100 for a subpolar and subtropical time-series. Under a high CO2 emissions scenario, the seasonal range of pH is found to be strongly enhanced for the subpolar time-series and moderately reduced for the subtropical time-series, with both being due to changes in seawater buffer capacity. / Graduate / 0425 / 0415 / robdj87@hotmail.com

CAVALCANTE, Davi de Holanda. Relação dureza/alcalinidade da água e seus efeitos sobre a qualidade da água, do solo e desempenho zootécnico de juvenis de tilápia do Nilo, Oreochromis niloticus, mantidos em condições laboratoriais. 2012. 45 f. : Dissertação (mestrado) - Universidade Federal do Ceará, Centro de Ciências Agrárias, Departamento de Engenharia de Pesca, Fortaleza-CE, 2012 / Submitted by Nádja Goes (nmoraissoares@gmail.com) on 2016-07-12T12:39:53Z No. of bitstreams: 1 2012_dis_dhcavalcante.pdf: 709236 bytes, checksum: 9209871af74fd8907329109402288391 (MD5) / Approved for entry into archive by Nádja Goes (nmoraissoares@gmail.com) on 2016-07-12T12:40:24Z (GMT) No. of bitstreams: 1 2012_dis_dhcavalcante.pdf: 709236 bytes, checksum: 9209871af74fd8907329109402288391 (MD5) / Made available in DSpace on 2016-07-12T12:40:24Z (GMT). No. of bitstreams: 1 2012_dis_dhcavalcante.pdf: 709236 bytes, checksum: 9209871af74fd8907329109402288391 (MD5) Previous issue date: 2012 / The present work aimed to determine the effects of unbalanced calcium hardness/total alkalinity (CH/TA) ratios on the water quality, soil quality and growth performance of Nile tilapia, Oreochromisniloticus, juveniles, reared in controlled conditions. Besides, it was also sought if the possible adverse effects of the unbalanced CH/TA ratios of fish growth performance could be minimized by the fish culture water’s total alkalinity (TA) increasing. The experimentswerecarried out in theLaboratório de Ciência e Tecnologia Aquicola – LCTA, ofthe Departamento de Engenharia de Pesca, Centro de Ciências Agrárias, Universidade Federal do Ceará, Fortaleza, Ceará.In this study, three complete experiments were performed. In each trial, there were six experimental groups, which were distributed according to a totally randomized design, in a 2 x 3 factorial arrangement. The first factor under scrutiny was the TA of the culture water in two levels (50 and 100 mg L-1 CaCO3 eq.).The second factor was the CH/TA ratio of the culture water in three levels (1/2, 1/1 and 5/1). In the first experiment, fish were reared in the roofed room of the laboratory, using 30 polyethylene circular 100-L tanks with no addition of bottom substrate. The second experiment was carried out in the same room used in the previous experiment, but the bottom of the tanks received a 5-cm layer of sand substrate. The third experiment was carried out in the open area of the lab in which the tank water is exposed directly to sunlight. In this last experiment, there were 36 polyethylene circular 250-L tanks with no bottom substrate. The respective stocking densities were 4, 3 and 6 fish per tank and the experiments lasted 10 (1st) and 8 (2nd and 3rd) weeks. No significant differenceswere observed between the treatments for the TA of water (50 and 100 mg L-1 CaCO3 eq.). On the other hand, there was fish growth performance impairmentcaused by the unbalanced CH/TA ratios (1/2 and 5/1) of water when compared to the control (CH/TA ratio = 1/1). The negative impact of the unbalanced CH/TA ratios on fish growth performance, either upwards (CH/TA > 1) or downwards (CH/TA < 1),was dependent on the degree that there wasbetween the absolute values of hardness and alkalinity. Small unbalance in the CH/TA ratio of culture water causedlittle growth retardation, but the higher unbalance produced considerable impairment in fish growth. / Este trabalho teve como objetivo determinar os efeitos de relaçõesdureza/alcalinidade da água desequilibradas sobre a qualidade da água, do solo e o desempenho zootécnico de juvenis de tilápia do Nilo, Oreochromisniloticus, mantidos em condições laboratoriais.Além disso, buscou-se determinar se os possíveis efeitos adversos decorrentes das relações dureza/alcalinidade da água desequilibradas sobre o crescimento dos peixes poderiam ser minimizados pela elevação da alcalinidade total da água de cultivo.Os experimentos foram realizados no Laboratório de Ciência e Tecnologia Aquicola – LCTA, do Departamento de Engenharia de Pesca, Centro de Ciências Agrárias, Universidade Federal do Ceará, Fortaleza, Ceará. Neste trabalho, foram realizados três experimentos completos. Em cada trabalho, havia seis grupos experimentais, distribuídos segundo delineamento inteiramente casualizado (DIC), em arranjo fatorial 2 x 3. O primeiro fator avaliado foi a alcalinidade total (AT) da água de cultivo, havendo dois níveis, 50 e 100 mg L-1 CaCO3 eq. O segundo fator avaliado foi a relação dureza cálcica/alcalinidade total (DC/AT) da água, onde foram testadas três relações, 1/2, 1/1 e 5/1.No primeiro experimento, os peixes foram cultivados na sala coberta do laboratório, em30 tanques circulares de polietileno com volume útil de 100 litros cada um. Nesse trabalho, não havia substrato arenoso nos tanques de cultivo.O segundo experimento foi realizado nas mesmas condições experimentais do experimento anterior, exceto pela presença de substrato de fundo nos tanques de cultivo, formado por uma camada de aproximadamente 5 cm de areia em cada tanque. O terceiro experimento foi realizado na área descoberta do laboratório, onde há exposição da água dos tanques à radiação solar. Nesse trabalho, foram utilizados 36 tanques de polietileno com volume útil de 250 litros cada um. No início dos trabalhos, foram estocados, quatro, três e seis peixes em cada tanque dos experimentos 1, 2 e 3, respectivamente. O primeiro experimento durou 10 semanas; os dois últimos, oito semanas.Não houve diferença significativa no desempenho zootécnico dos peixes entre as AT de 50 mg L-1 CaCO3e 100 mg L-1 CaCO3.Por outro lado, houve prejuízo zootécnico para as relações DC/AT desequilibradas de ½ e 5/1, em relação ao grupo-controle (relação DC/AT de 1/1). O impacto negativo do desequilíbrio das relações DC/AT, tanto para cima (DC/AT > 1), como para baixo (DC/AT < 1), dependeu da magnitude da diferença existente entre os valores absolutos de dureza e alcalinidade. Pequeno desequilíbrio na relação DC/AT da água causou prejuízos mínimos aos peixes, mas desequilíbrio acentuado causou grandes prejuízos zootécnicos.