Treatment of Rainbow Trout (Oncorhynchus mykiss) Raceway Effluent Using Baffled Sedimentation and Artificial Substrates. The treatment performance of a 6 m wide by 67 m long by 0.8 m deep, baffled sedimentation basin receiving rainbow trout <i>(Oncorhynchus mykiss)</i> raceway effluent was evaluated with and without the installation of artificial substrates (Aquamats®). Treatment efficiency was also determined using normal rearing condition effluent loading versus cleaning and harvesting events. Total suspended solids (TSS) removal for the total basin averaged 79% and 71% during normal rearing conditions, as compared to 92% and 79% during cleaning and harvesting operations, when the Aquamats® were installed versus removed, respectively. Total phosphorus (TP) removal by the total basin, with and without Aquamats®, was 20% and 23% during normal rearing conditions as compared to 55% and 65% under cleaning and harvesting conditions, respectively. Higher TP removal during cleaning operations was attributed to sedimentation of particulate fractions. Dissolved nutrient removal (ortho-phosphate (OP), total ammonia nitrogen (TAN), nitrate, nitrite, and total organic carbon (TOC)) was not consistent throughout the basin and did not improve when the Aquamats® were installed. A short contact time and periphyton grazing by isopods may have limited the capacity of the Aquamats®. Calculated retention times with and without Aquamats® for the first half and total basin were 37% and 32% and 27% and 17% less than theoretical values, respectively based on a rhodamine WT dye study. Average surface overflow rates were adjusted accordingly and measured 19.1 m³/m²-day when the Aquamats® were installed, versus 14.8 m³/m²-day when the Aquamats® were removed for the overall basin. These rates are lower than previous recommendations for treating aquaculture effluents, but resulted in with high solids removal and consistently low TSS effluent (average < 2 mg/L) which may be necessary for strict discharge permits. Use of the overall basin minimized the occurrence of TSS measurements > 2 mg/L by 50%. For the first half of the sedimentation basin, the overflow rate averaged 44.1 m³/m²-day with Aquamats® versus 35.8 m³/m²-day without Aquamats®. The majority of effluent treatment occurred within the first half of the basin, which was responsible for 84% and 94% of total TSS removal, 42% and 100% and 61% and 80% of total TP removal during normal and cleaning/harvesting conditions, respectively.> Characterization of Nutrient Leaching Rates from Settled Rainbow Trout <i>(Oncorhynchus mykiss)</i> Sledge The leaching of nutrients from settled rainbow trout <i>(Oncorhynchus mykiss)</i> sludge into overlying water was evaluated over a 7 day period. Nutrient leaching was assessed in a stagnant reaction tank and one agitated by aeration to simulate turbulent conditions in stocked production raceways. Leaching of total phosphorus (TP), ortho-phosphate (OP), total Kjeldahl nitrogen (TKN), total ammonia nitrogen (TAN), and total organic carbon (TOC) occurred rapidly during the first 24 h in both stagnant and agitated conditions. The highest 24 h leaching occurred in the agitated tank, and power regression equations accurately described the varying rates of increasing TP, OP, TAN and TKN. In the stagnant tank, linear increases of TP, OP, TKN and TAN concentrations occurred during the first 24 h. These linear increases continued from day 2-7, but at slower rates than occurred during the first 24 h. Average nutrient leaching rates (mg leached/g sludge-h);(dry weight basis) were calculated based on linear concentration increases. In the agitated tank, nutrient concentrations decreased after 60 h, as aerobic bacterial uptake and/or chemical precipitation was suspected. Therefore, average leaching rates could not be determined. These findings reveal that daily cleanout of settling areas could eliminate the release of TP, OP, TAN, TKN, and TOC from settled solids by 66%, 65%, 39%, 76% and 51%, respectively, as compared to weekly cleanout schedules. Sustained leaching rates indicate nutrient release will likely continue beyond 7 days. This information suggests aggressive and continuous sludge management is most beneficial for maintaining high water quality and regulatory discharge compliance in fish production. / Master of Science

The effects of oxygenation and aeration on water quality, rainbow trout (Oncorhynchus mykiss) production, and economics were compared at the Wytheville State Fish Hatchery (WSFH) for 270 days. Mean dissolved oxygen (DO) concentrations and delta DO were significantly higher (P < 0.001) in the oxygenated raceways (9.5 and 2.75 mg/L, respectively) compared to aerated raceways (7.4 and 0.57 mg/L). Total settleable solids loads were significantly greater (P < 0.001) in aerated raceways (10.3 g/L/day) than in oxygenated raceways (8.8 g/L/day). Dissolved nitrogen (%), total gas pressure, and other water quality parameters (CO2, nitrite nitrogen, alkalinity, pH, and TAN) did not differ significantly between the treatments (P > 0.05). Raceway trout production (kg/day), trout growth rates (grams), feed conversion rate (FCR), and fish survival were not significantly different between treatments (P > 0.05). Blood hematocrit (Hct) and percent visceral mass were significantly elevated (P < 0.001) in oxygenated raceways compared to aerated raceways at 46 and 14.4% and 44 and 13%, respectively. Carrying capacity estimates derived from fish loading trials were significantly different (P < 0.001) at 3,355 and 2,217 kg/raceway in oxygenated and aerated raceways, respectively. Estimates of carrying capacity calculated using a fish loading (Ld) equation were also significantly different (P < 0.001) at 1,530 and 990 kg for oxygenated and aerated raceways, respectively. Oxygen injection increased the cost of production by $0.20/kg, however, net present value analysis (NPV) of oxygenated and aerated raceways over 5 years at a 10% discount rate yielded estimates of $50,666.51 and $32,742.15, respectively. Oxygen injection is an effective means of increasing DO concentrations, reducing effluent solids loading, and increasing raceway carrying capacity. / Master of Science

International Telemetering Conference Proceedings / October 27-30, 1997 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The purpose of this paper is to describe the development of a very high-speed instrumentation and digital data recording system. The system converts multiple asynchronous analog signals to digital data, forms the data into packets, transmits the packets across fiber-optic lines and routes the data packets to destinations such as high speed recorders, hard disks, Ethernet, and data processing. This system is capable of collecting approximately one hundred megabytes per second of filtered packetized data. The significant system features are its design methodology, system configuration, decoupled interfaces, data as packets, the use of RACEway data and VME control buses, distributed processing on mixedvendor PowerPCs, real-time resource management objects, and an extendible and flexible configuration.

A injeção de carvão pulverizado (pulverized coal injection - PCI) é uma técnica largamente utilizada nos altos-fornos pelas siderúrgicas brasileiras, seguindo uma tendência mundial, que busca reduzir o consumo específico de coque por tonelada de gusa e, em consequência, do custo do ferro gusa produzido. A combustão do carvão pulverizado ocorre sob pressões médias (de até 4 atm), temperaturas de chama elevadas (em torno de 2 000 °C), altas taxas de aquecimento (104 a 105 °C/s), tempo de residência muito curtos (inferiores a 40 ms), e é seguida pela gaseificação na presença de CO2. Como não existem métodos padronizados para a avaliação das características de combustão dos carvões para sua utilização em PCI, utilizam-se geralmente equipamentos de injeção de carvão em escalas laboratorial e de bancada, além plantas-piloto com este propósito. O objetivo principal deste trabalho é apresentar as etapas do desenvolvimento de um equipamento em escala de bancada realizado no Laboratório de Siderurgia da Escola de Engenharia da UFRGS (LASID-UFRGS), desde o projeto conceitual até a fase pré-operacional, e os resultados iniciais obtidos, para estudar as características de combustão dos carvões em condições bastante similares às que ocorrem nos altos-fornos. Os testes iniciais incluem a avaliação da combustão de um carvão brasileiro objetivando seu uso potencial em PCI, em substituição parcial de carvões importados para este fim. Optou-se por um projeto moderno, altamente automatizado, que inclui aquisição rápida de dados, com escala e conceito operacional adequados para estudos acadêmicos, de configuração vertical e que possibilitasse a operação no modo de injeção de uma amostra de carvão em pulso único, bem como uma adequação futura ao modo de injeção contínua de carvão. Algumas características relevantes do equipamento são a medição e aquisição ultrarrápida de dados termodinâmicos de pressão e temperatura em diversos pontos do sistema, permitindo o registro dos fenômenos transientes que ocorrem durante a combustão, a possibilidade de programação e controle de tempos, pressões e temperaturas para testes de combustão e de pirólise através de rotinas especialmente desenvolvidas para isto, bem como a coleta representativa dos produtos sólidos e gasosos resultantes da combustão para posterior análise. É ainda possível a filmagem da xvi combustão em modo ultrarrápido, permitindo correlacionar as imagens aos dados termodinâmicos registrados durante a combustão ao longo de um segundo, em intervalos de poucos milissegundos. Os resultados iniciais obtidos na fase pré-operacional demonstram o bom funcionamento do sistema, permitindo distinguir claramente a influência da variação de parâmetros operacionais como tipo de carvão, massa e de amostra injetada, pressão e temperatura de operação e composição dos gases oxidantes. / Pulverized coal injection (PCI) is a technique used in blast furnaces (BFs) by Brazilian steel industry, following a worldwide trend, to reduce coke consumption by ton of hot metal produced, and therefore reducing the overall cost. Burning of pulverized coal injected into tuyeres of BFs takes place under medium pressure (up to 4 atm), high flame temperatures (around 2 000 °C), very fast heating rates (104–105 °C/s) and very short residence times, less than 40 ms, followed by gasification in presence of CO2. Since there are no standard tests for evaluation of coal combustibility at PCI conditions, lab and bench scale coal injection rigs and pilot plants are usually employed for this purpose. This work shows the development steps of a bench-scale rig, built at the Iron and Steelmaking Laboratory of the School of Engineering - Universidade Federal do Rio Grande do Sul (LASID-UFRGS), from the conceptual design to the pre-operational step, as well as the initial results. This equipment permits to study the combustion characteristics of coals in conditions very close to those occurring in blast furnaces. Initial tests include the combustion evaluation of a Brazilian coal, aiming its potential usage for PCI, in partial substitution of imported coals for this purpose. The rig has a modern design and is highly automated. Its scale and operational concept is fitted for academic studies. It has a vertical configuration, to be operated with injection of a coal sample in a single pulse mode and is capable to be adjusted afterwards to continuous coal injection mode. Some relevant characteristics of the injection rig are: (1) the very fast measurement and acquisition of thermodynamic data of pressure and temperature in several points of the system, allowing the capture of transient phenomena occurring along the combustion process; (2) the possibility of programming and controlling time intervals, pressures and temperatures to perform combustion and pyrolysis tests, employing specially developed routines; and (3) the representative sample collection of solid and gaseous combustion products to be further analyzed. It is also possible to capture images of the combustion by a high-speed camera, allowing correlate the images, acquired during a time interval of one second, with the thermodynamic data collected in intervals of few milliseconds. xviii The good performance of the equipment was shown by the initial results obtained at the pre-operational phase. The experimental data clearly depicted the effect of operational parameters like coal type, injected sample mass, operational pressure and temperature, and oxidizing gas composition.

Microalgae produce large quantities of lipids that can be used for biofuel feedstock. The goal of this project was to determine the effect of several engineering and management parameters on the productivity of microalgae cultivated in large, outdoor facilities. The specific objectives were focused on the effects of inoculation ratios; the effects of light, temperature, and culture depth on growth; and the minimum circulation velocity necessary to maintain growth and minimize settling in open ponds. Microalgae must first be cultured in smaller quantities before the raceway is inoculated for optimized growth. Concentration ratios are defined as the ratio of the volume of microalgae inoculum to the volume of new growth media. The microalgae species used was Nannochloris oculata (UTEX #LB 1998). Inoculation ratios studied varied from 1:1 to 1:32 and were grown in 500 mL Erlenmeyer flasks. The study found that 1:16 and 1:32 were too dilute, while the 1:8 concentration had the largest growth rate. Determination of the effects of temperature, light intensity, and cultivation depth is critical to maintaining healthy cultures. Excess light intensity can result in photoinhibition and temperatures above the maximum growing tolerance can have detrimental effects. These factors can affect growth and evidence suggests an interaction that exacerbates these effects. In an outdoor culture there are few practical control variables other than pond depth. As cultivation depth increases, the algae undergo "selfshading" and the increased cultivation volume hinders temperature changes. Scaled raceway ponds were maintained at 10.16 cm (4 inch) and 13.97 cm (5.5 inch) depths. The species used was Nannochloris oculata and it was found to grow best at 785 micromol m⁻² s⁻¹m^-2 s^-1, 20°C, and 10.16 cm. Diatoms are attractive because of high growth rates, faster lipid production, and greater cell density. The latter promotes rapid settling once mixing has stopped. Because of the silica cell wall composition, diatoms are believed to be more susceptible to shear forces which can result in lysis. Determining the natural settling rate to the minimum channel velocity relationship in cultivation ponds was the objective. No flocculants/coagulants were added which created a case of "natural" settling. Four pennate Nitzschia sp. and one centric diatom were tested in a jar tester. There was no significant difference in settling times between the species. The mean settling time was 4.55 cm min⁻¹ and the minimum channel velocity was determined to be 10.12 cm min⁻¹.

America's reliance on foreign oil has raised economic and national security issues, and in turn the U.S. has been active in reducing its dependence on foreign oil to mitigate these issues. Also, the U.S. Navy has been instrumental in driving bio-fuel research and production by setting an ambitious goal to purchase 336M gallons of bio-fuel by 2020. The production of microalgae biomass is a promising field which may be able to meet these demands. The utilization of microalgae for the production of bio-fuel requires the implementation of efficient culturing processes to maximize production and reduce costs. Therefore, three discrete rate event simulation models were developed to analyze different scaling scenarios and determine total costs associated with each scenario. Three scaling scenarios were identified by this analysis and included a stepwise, volume batching and intense culturing process. A base case and potential best case were considered in which the culturing duration, lipid content and lipid induction period were adjusted. A what-if analysis was conducted which identified and reduced capital and operational costs contributing greatly to total costs. An NPV analysis was performed for each scenario to identify the risk associated with future cash flows. The research findings indicate that the intense culturing scaling scenario yielded the greatest model throughput and least total cost for both the base case and potential best case. However, this increased productivity and cost reduction were not significantly greater than the productivity generated by the stepwise scaling scenario, suggesting that the implementation of flat plate bio-reactors in the intense culturing process may be non-advantageous given the increased operational costs of these devices. The volume batching scenario yielded the greatest total cost L^-1 of microalgae bio-oil for both, indicating an inefficient process. The scaling scenarios of the base case and potential best case yielded negative NPV's while the stepwise and intense culturing scenarios of the what-if analysis generated positive NPV's. The base case is based on current technological advances, biological limitations and costs of microalgae production therefore, a negative NPV suggests that utilizing microalgae for bio-fuel production is not an economically feasible project at this time.

Made available in DSpace on 2016-06-02T19:22:06Z (GMT). No. of bitstreams: 1 3251.pdf: 2426024 bytes, checksum: a69a0d5cfd82be120ca06c5161b0a032 (MD5) Previous issue date: 2010-03-10 / Financiadora de Estudos e Projetos / Fishes as well as other group of species can accrue benefits from adapting to aerobic exercises. Examples of these benefits are: higher growth and feed conversion rates, less aggressive behavior, and optimization of non-nitrogenous nutrient as source of metabolic energy. The aim of this work was to evaluate growth and metabolic responses of pacu (Piaractus mesopotamicus) to aerobic swimming speeds and diets, varying in proportions of carbohydrates and lipids. Two experiments were carried out. One of it aimed to determining the ideal aerobic swimming speed for pacu; three speeds were compared: 1 body-length per second (BL/sec), 2 BL/sec, and 3 BL/sec besides a control treatment (non-exercised). In the second experiment the fish were kept at non-exercising or swimming at the ideal speed determined in the previous experiment, and submitted to different feeding regimes, in which the diets presented varying proportions (%) of carbohydrate and lipid, respectively: 27/15, 36/10 and 45/5. In both experiments, treatment effects were evaluated in terms of zootechnical parameters, several hematological variables, and intermediary plasmatic, hepatic and muscle tissue (white and red) intermediary metabolites and several metabolic enzyme activities. It was concluded from the first experiment that swimming at 2 BL/sec was ideal for pacu, considering the comparatively higher rate of growth and a metabolic response indicative of a higher utilization of non-protein sources for energy production. The spare-protein effect was also observed under the 1 and 2 BL/sec treatments while higher levels of protein oxidation, possibly for the maintenance of energy levels, and adequate levels of glycemia were observed in the individuals kept swimming at 3 BL/seg. In the second experiment, the best growth rates were presented by swimming fishes kept under the 36/10 feeding regime; a higher participation of lipids as metabolic energy supplier was also noted under this regime. It was concluded that pacu submitted to aerobic swimming at 2 BL/sec and fed with diet containing 36% lipids and 10% carbohydrates presented better growth performance and higher efficiency in directing non-protein sources for metabolic energy production. / A adaptação ao exercício aeróbico traz vários benefícios aos peixes, como: maior crescimento, taxas de conversão alimentar eficientes, diminuição do comportamento agressivo e otimização da utilização de fontes não-nitrogenadas como combustível energético. O objetivo deste trabalho foi avaliar as respostas metabólicas e de crescimento de pacu (Piaractus mesopotamicus) submetido a diferentes velocidades de natação aeróbica, e à associação da prática da atividade natatória a diferentes dietas contendo níveis variáveis de carboidratos e lipídios. Dois experimentos foram realizados. No primeiro verificaram-se as respostas de crescimento e bioquímico-fisiológicas de pacus submetidos a três velocidades de natação aeróbica: 1comprimento corporal por segundo (CC/seg), 2CC/seg e 3CC/seg. No segundo, avaliaram-se as mesmas respostas de pacus submetidos à velocidade ideal determinada no primeiro experimento, e alimentados com diferentes regimes de alimentação, com níveis variados de carboidratos e de lipídeos. As dietas utilizadas constituíram-se nas seguintes proporções: 27%ENN e 15%EE, 36%ENN e 10%EE, e 45%ENN e 5%EE. Em ambos os experimentos analisaram-se parâmetros de desempenho, variáveis hematrimétricas, íons plasmáticos (apenas no primeiro experimento), metabolismo intermediário plasmático, hepático e dos tecidos musculares branco e vermelho, e enzimas do metabolismo intermediário em fígado, músculo branco e vermelho. O primeiro experimento revelou que a velocidade de natação ideal para pacus, nas condições ensaiadas, foi de 2CC/seg, pois houve adaptação metabólica para atender a demanda exigida pelo exercício, com melhores respostas de crescimento e quadro metabólico sugestivo de maior utilização de fontes não-protéicas para geração de energia. O efeito poupador de proteína foi observado nos grupos 1CC e 2CC, assim como maior oxidação protéica para manter os níveis energéticos e a glicemia adequados no grupo 3CC. No segundo experimento observaram-se, sob exercício a 2CC/seg., os melhores valores de crescimento foram encontrados em peixes alimentados com a dieta 36/10. Nesta condição, observou-se maximização da utilização dos substratos energéticos, com maior participação dos lipídeos como mantenedores da atividade física. Conclui-se assim que, pacus submetidos ao exercício aeróbico, à velocidade de 2CC/seg e alimentados com 36% de carboidratos e 10% de lipídeos (36/10), apresentam excelente desempenho de crescimento e redirecionam melhor fontes não-nitrogenadas para fins energéticos.

Made available in DSpace on 2016-06-02T19:29:03Z (GMT). No. of bitstreams: 1 TeseGAAR.pdf: 1428971 bytes, checksum: 30750dc9914f1a7930baa8484ccd49cb (MD5) Previous issue date: 2007-02-28 / Universidade Federal de Sao Carlos / Fast growth, followed by high stocking density set up productivity and profitability in aquaculture intensive systems. These are actually challenges for fish producers and researchers. Matrinxa, Brycon amazonicus is a Neotropical Characiform that presents high growth rates, good quality filet, easy adaptation to artificial diets, and good commercial values. It is a reofilic species, demands good waters, lives in rapids, shows a biological plasticity, which make it proper to intensive fish culture. It presents a good potential to studies on sustained exercise and under high stocking densities. Therefore, the present study was focused in the investigation of the swimming effects on growth, stocking density and body composition as well as in the evaluation of the metabolic responses and adaptive aspects in juvenile matrinxa submitted to increasing swimming speeds associated to long term sustained exercise. To investigate the effects of swimming speeds, 100 juveniles of matrinxa with initial average weight and size of 33.33±0.95 g and 13.44±0.10 cm respectively were transferred to five fiber glass tanks under water speed of: 0.0; 1.0; 1.5; 2.0 and 2.5 BL/sec (body length) for 90 days. In a second trial 210 juveniles of matrinxa with average length and size of 18.44±0.1 g and 12.33±0.5cm respectively, were divided into two groups. One group was endured at 1BL/sec and stocked at three densities (88, 176 and 353 fish per m3) in circular tanks of 250L; a second group of fish were endured the same density conditions but without exercise for 70 days. The water speed affected the growth in both trials. In the first trial the highest growth rates were observed in fish that swam 1 and 1.5 BL/sec. The average weight was 20% higher than control and than the highest water speed (2.5 BL/sec). In the second trial the highest growth and survival were observed in the exercised group and stocked in the average density. The adaptive responses biochemical, physiological observed through the intermediary metabolites in plasma and tissues (liver, white muscle and red muscle), hematological parameters, ions, hormonal, in the juveniles of matrinxa under several water speed and several stock densities indicate that matrinxa is a fish species well responsive to exercise stimulus, and adapts easily to confinement at high stock densities. / Rápido crescimento em altas densidades de estocagem determina a produtividade e a rentabilidade de sistemas de aqüicultura intensiva e são desafios de pesquisadores e de produtores. O matrinxã, Brycon amazonicus, é um Characiforme do neotrópico que exibe alta taxa de crescimento, carne de excelente qualidade, fácil adaptação a dietas artificiais e alto retorno econômico. A espécie é riofilica, exigente em qualidade da água ocorre em habitats de corredeira, por seu formato fusiforme e exibir uma plasticidade biológica o que possibilita sua adaptar-se à piscicultura intensiva, apresenta amplo potencial para estudos direcionados ao crescimento em condições de exercício sustentado e em altas densidades de estocagem. Neste sentido, o presente estudo teve como objetivo investigar os efeitos da natação sustentada no crescimento, na densidade de estocagem e na composição corporal, assim como avaliar as respostas metabólicas e alguns aspectos adaptativos (forma e função) em juvenis de matrinxã, submetidos a velocidades crescestes de natação e a diferentes densidades de estocagem associadas ao exercício continuo de longa duração. Para investigar os efeitos das velocidades de natação, cem juvenis de matrinxã com peso e comprimento médio inicial de 33,33±0.95 g e 13,44±0,10 cm, respectivamente, foram estocados em cinco caixas de fibra de vidro de 250 L-1 e submetidos a nadar a cinco velocidades da água: 0,0; 1,0; 1,5; 2,0 e 2,5 cc/seg (comprimento corporal por segundo) durante 90 dias. Na segunda fase, 210 juvenis de matrinxã peso e comprimento médio de 18,44±0,1 g e 12,33±0,5 cm, respectivamente, foram distribuídos em dois grupos: um grupo de peixes foi forçado a nadar a uma velocidade de 1,0 cc/seg e estocado em três densidades (88, 176 e 353 peixes/m3), em tanques circulares de 250 L-1. O segundo grupo de peixes foi submetido às mesmas condições de densidade, mas sem exercício forçado por um período de 70 dias. A velocidade da água afetou o crescimento em ambos experimentos, no primeiro experimento, as maiores taxas de crescimento foram observadas nos peixes que nadaram entre 1,0 e 1,5 cc/seg, sendo o peso destes peixes 20% maior ao grupo controle e ao grupo que nadou na maior velocidade da água (2,5 cc/seg). No segundo experimento, o maior crescimento e sobrevivência foi observado no grupo de peixes exercitado e estocado na média densidade (173 peixes/m3). As respostas bioquímicas e fisiológicas adaptativas elucidadas através das alterações dos intermediários metabólicos a nível plasmático e tecidual (fígado, músculo branco, vermelho) e dos parâmetros hematológicos, iônicos e hormonais dos juvenis de matrinxã criados em condições de diversas velocidades da água e em varias densidades de estocagem indicam que o matrinxã é uma espécie que responde bem ao estimulo do exercício e adapta-se bem ao confinamento em altas densidades sob natação sustentada.

The economics of microalgal bioproduct commercialization would benefit from increased accumulation of energy storage compounds, such as carbohydrates and lipids, and increased biomass productivity. This thesis explores two adaptive laboratory evolution strategies for improving Scenedesmus obliquus: single UV-mutagenesis and low light cultivation at a high dilution rate to produce cultigens with greater carbohydrate content and iterative UV-mutagenesis and selection under outdoor conditions in a raceway pond at a high dilution rate to increase biomass productivity. Two cultigens were generated with the goal of increased carbohydrate content: K5 and K7. Both were mutagenized for 5 seconds and cultivated in 50-mL Klavins reactors. K5 was maintained at 95 μmol/m2-sec for 16 hours/day, and K7 was maintained at 250 μmol/m2-sec for 6 hours/day. When evaluating the two cultigens in triplicate 800-mL bubble columns against wild-type Scenedesmus obliquus, neither K5 nor K7 demonstrated an increase in carbohydrate content. To increase biomass productivity, Scenedesmus obliquus was iteratively UV-mutagenized (aliquots exposed for 5-60 seconds were combined) and cultivated in a 100-L, 0.5-m2 outdoor raceway pond fed with filtered reclaimed wastewater at a high dilution rate. Three rounds of mutagenesis and selection took place during the spring, summer, and winter months, with the MBE 509 and MBE 510 cultigens being produced after the summer and winter selection rounds, respectively. When evaluated in triplicate 800-mL bubble column reactors: MBE 509 (491 ± 42 mg/L-day, expressed as the mean of the time series ± SD) was 24% more productive than wild-type (397 ± 39 mg/L-day), and MBE 510 (443 ± 26 mg/L-day) was 13% more productive than wild-type (391 ± 9 mg/L-day). When evaluated in replicate 1,350-L, 4.5-m2 raceway ponds, MBE 509 (15.2 ± 2.2 g/m2-day) and MBE 510 (16.1 ± 1.8 g/m2-day) were 5% and 12% more productive than wild-type (14.5 ± 2.4 g/m2-day), respectively. Selection under low light and high dilution did not result in cultigens with higher carbohydrate content relative to wild-type Scenedesmus obliquus, but iterative mutagenesis and selection in an outdoor raceway pond did generate cultigens with higher biomass productivity in both indoor and outdoor environments.

While treating domestic wastewater, algae can be grown and harvested for biofuel production. Water is a vital resource and it is imperative to conserve and reuse as much as possible. Several pilot and lab scale experiments were conducted to further research into a full scale wastewater treatment and biofuel production facility. This thesis will include these topics: nitrogen and phosphorus concentrations of clarified wastewater pond feed, nitrogen and phosphorus transformations by algae, and the potential of algae cell disruption technologies to increase nutrient solubilization. The pilot scale experiments were conducted using nine 33 m2, 0.3 m deep multi-culture raceway algae ponds being continuously mixed. These ponds were setup in triplicates and fed municipal wastewater in the form of primary clarifier effluent. The three experiments conducted using these pilot scale ponds were: grab and 24-hour composite influent comparison, nitrogen and phosphorus of various hydraulic residence times (HRTs), and nitrogen and phosphorus nutrient depletion with water recycle. The grab and 24-hour composite comparison was conducted from July 30 to December 3, 2014 and compared the dissolved reactive phosphorus (DRP) and total ammonia nitrogen (TAN) concentrations of the two sample types. Equations were made to convert from grab to 24-hour concentrations. The sample types for both DRP and TAN were on average within 10% and essentially the same. A comparison of data from ponds operating at different HRTs was collected from October 30 and November 6, 2013 and October 29 and November 5, 2014. There were linear correlations between different HRTs and both soluble nitrogen and DRP. Equations were made to calculate the expected removal of ponds using the HRT. The nutrient depletion with water recycle experiment was conducted during October 15-29, 2015. Soluble nitrogen removal was linear with a rate of 1.5 mg-N/L-day and required 14 days to drop below 5 mg-N/L in the ponds. DRP removal was also linear with a rate of 0.18 mg-P/L-day. The algae cell disruption solubilization experiments were conducted using homogenization, sonication, autoclaving, and boiling pretreatment technologies. Algae harvested from the pilot ponds was anaerobically digested and then aerobically digested in an attempt to reuse nutrients for continued growth. It was found that there was no significant difference between the pretreated and non-pretreated digested samples. Keywords: algae, raceway pond, nutrient transformation, anaerobic digestion, aerobic digestion, assimilation, volatilization, nitrogen, phosphorus, pretreatment of algae, nutrient resolubilization, nutrient solubilization