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1
Parker, Edward V. "Oxygen management at a commercial freshwater recirculating aquaculture system." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0032/MQ65513.pdf.
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Singh, Sahdev. "Modeling thermal environment of a recirculating aquaculture system facility." Thesis, This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-12302008-063343/.
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Montorio, Luca. "Assessment of a novel filter system for recirculating aquaculture." Thesis, University of Stirling, 2004. http://hdl.handle.net/1893/25419.
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The aim of this project was to investigate the usage of manganese dioxide ore as a bio-filter media to remove metabolites in aquaculture closed system, and to determine whether manganese toxicity would at the same time represent a risk to fish. Initial work investigated the physical properties of manganese dioxide and its chemical interaction with ammonia and nitrite in the absence of biological activity. Subsequently, two pilot-scale pressurised filters were installed in a commercial scale hatchery in order to compare the metabolite removal performance of manganese dioxide against silicate sand in the presence of biological activity commonly found in aquaculture conditions. The investigation suggests that Mn medium is more reliable in converting ammonia to nitrate without producing a residual output of nitrite. The superior performance ofMn media compared with sand appears to be mainly related to the physical structure of the manganese ore. Furthermore, the Mn medium did not appear to be soluble in the ambient conditions normally found in aquaculture-closed system. From the design point of view, due to the higher ammonia and nitrite removal rates, a shorter retention time and a lower volume of media are required in the case of manganese dioxide technology compared with sand media. As a result, it is much easier to size a biofilter with Mn media. Manganese systems have a comparable total costs to conventional sand media, but using the Mn technology provides a more reliable control of toxic nitrite, thereby reducing risks offish loss and hence with reduced expected production costs.
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Bst, Neil A. (Neil Andrew). "Preliminary design of a recirculating aquaculture system in Boston Harbor." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/10275.
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Yates, J. Kevin. "Production economics of summer flounder Paralichthys dentatus aquaculture in a recirculating system /." Electronic version (PDF), 2004. http://dl.uncw.edu/etd/2004/yatesj/jkevinyates.pdf.
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Guan, Lu. "Nitrogen Removal from Closed Aquaculture System by Bio-electrochemical System." Thesis, Virginia Tech, 2018. http://hdl.handle.net/10919/91468.
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Removal of nitrogen elements in culture water is one of the major concerns in recirculating aquaculture system (RAS). Maintaining a low concentration of nitrogen compounds is essential for a good quality of aquaculture production. Due to fish is very sensitive to the toxic ammonium/ammonia, nitrification biofiltration tank is often an integrate part of filtration in RAS to remove ammonium via nitrification. However, nitrate accumulation via nitrification in RAS is often observed during the operation, which is usually solved by replacing with the fresh water into the system. With the concern of water consumption, bio-electrochemical system (BES) is introduced in this study to realize simultaneous nitrate removal for the system while generating the electricity through electron transferring. A microbial fuel cell (MFC) with an anion exchange membrane (AEM) was constructed. The removal of nitrate from aquaculture water generated from RAS was achieved by nitrate migration across the AEM and heterotrophic denitrification in the anode chamber. To further investigate the potential application of BES in RAS, the cathode chamber was incubated with biofilm to do the nitrification while the denitrification processing in the anode chamber. The study gave a total inorganic nitrogen removal efficiency of 38.72% ± 4.99, and a COD removal of 86.09% ± 9.83. The average daily electricity generation was 67.98 A m-3 ± 13.91, and nitrate-nitrogen concentration remained at 21.02 ± 2.62 mg L-1 throughout the experiment. These results of treating aquaculture water indicate that BES has a potential to install within RAS for enhanced nitrogen removal.MS
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Myers, Amanda R. ""Recirculating aquaculture system integration of bivalve culture for effluent nutrient composition reduction" /." Electronic version (PDF), 2006. http://dl.uncw.edu/etd/2006/myersa/amandamyers.pdf.
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Farzad, Razieh. "Novel Aquafeed Towards A Sustainable Aquaculture." Diss., Virginia Tech, 2018. http://hdl.handle.net/10919/103810.
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With World Health Organization estimation of population increase to over 9 billion by 2050, malnutrition and food insecurity are predicated to be two of the main challenges facing the world in the future. Fish is a source of protein that can have a significant contribution for solving the global food crisis. Fish for human consumption is provided by both the aquaculture industry and the capture fisheries, however, the flat-lined production of seafood from capture fisheries means aquaculture production should double in number to provide enough protein by 2050. Culturing fish at higher densities is being used as a way to increase the global aquaculture production. Modern aquaculture intensified practices expose the fish to various stressors that can negatively impact their welfare. Good nutrition can improve the health status of aquacultured fish while accumulation of specific nutrient can add value to the fillet. In line with that, the studies described in this dissertation aimed to examine the vital role of fish in human health and evaluate strategies to improve the sustainable aquaculture production of fish using novel aquafeeds. This was completed by conducting a survey of the essential minerals and heavy metals of commercially available catfish, salmon, and tilapia fillets in the United States marketplace and three fish nutritional trials to evaluate the impacts of novel aquafeeds on production and health of fish and the food quality of their respective fillets. Selenium with the established health benefit for human and fish was the trace mineral of interest in this dissertation. This element is the main component of a group of selenium containing proteins called selenoproteins that are antioxidant and maintain oxidative homeostasis of fish and human. Additionally, selenium is an antagonist for many heavy
metals such as mercury. The market study revealed that catfish, salmon and tilapia samples available in United States marketplace are good source of selenium, zinc and phosphorous. The concentration of heavy metals in all the samples were lower than safety standards. Nile tilapia (Oreochromis niloticus) and rainbow trout (Oncorhynchus mykiss), which are two economically important aquacultured fish, were used as animal models in the fish nutritional trials. Different forms of selenium supplemented to Nile tilapia diet. The form of Dietary Se form did not have any significant (p>0.05) effect on growth, and plasma and hepatic GPX activity of Nile tilapia. However, organic selenium supplement showed significantly (p<0.05) higher bioavailability and accumulated in the fillets at the significantly higher concentration. In the second fish trial selenoneine, a novel selenium containing compound, was supplemented at various concentrations to rainbow trout diet. Other than growth parameters multiple other health biomarkers (lysozyme, glutathione peroxidase, superoxide dismutase activities) were examined to determine whether selenoneine supplementation had a positive impact on fish health. Selenoneine enriched diet significantly(p<0.05) increased the weight gain, lysozyme and oxidative enzymes activities of rainbow trout. Lastly rainbow trout feed was supplemented with commercially available probiotic (Actisaf), prebiotic (Safmmann), and their mixture (synbiotic). These dietary supplements did not have any significant effect on fish production but led to a significant increase in activity of oxidative enzymes in plasma when compared to control diet. These results suggest that feed supplements used in this dissertation can be used to promote the fish health raised in recirculating aquaculture systems and support an economically and environmentally sustainable aquaculture.PHD
9
Nunley, Chad E. "Production of hybrid striped bass (Morone chrysops x Morone saxatilis) in a recirculating aquaculture system." Thesis, This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-08222009-040454/.
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Phillips, Jennifer Brooke. "Denitrification of Recirculating Aquaculture System Waters Using an Upflow Biofilter and a Fermented Substrate." Thesis, Virginia Tech, 1997. http://hdl.handle.net/10919/31068.
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The ability of an upflow, denitrifying biofilter using a fermentation generated carbon source to treat the high nitrate concentrations typically seen in recirculating aquaculture systems was studied using a synthetic nitrate wastewater supplied at two nitrate loadings, 1.13 and 2.52 kg NO3-N/m3/day. A supplemental carbon source was provided primarily through the fermentation of fish food which generated volatile fatty acids (VFA) in the form of acetic, propionic, isobutyric, n-butyric, 2-methylbutyric, 3-methylbutyric, and n-valeric acids. Acetic and propionic acids were the predominant constituents generated, while lower concentrations of the longer carbon chain butyric and valeric acids were produced. The VFAs proved to be a viable carbon source for the denitrification process as indicated by the ability of the biofilm to assimilate all of the constituents generated. Carbon limiting the system resulted in an increase in effluent nitrite and incomplete nitrate removal. During the low nitrate loading condition, influent COD to NO3-N ratios greater than 5 typically achieved high total nitrogen removals greater than 95%. This influent ratio corresponded with a COD to NOx -N consumption ratio of 4.62 ± 0.28 mg/L as COD per mg/L as N for complete nitrogen removal. Under the high nitrate loading condition, influent COD to NO3-N ratios achieving high nitrogen removals showed great variability and did not correspond to a distinct value. The COD to NOx -N consumption ratios were often below stoichiometric values, which was attributed to the hydrolysis of influent fermentation solids captured within the column to generate a COD source not measured by filtered samples. The column biofilm kinetics were modeled using a half-order reaction rate and denitrification coefficients (k) of 0.70 ± 0.02 (mg NOx-N/L)1/2 / min and 1.18 ± 0.12 (NOx-N /L)1/2 / min were determined for the low and high nitrate loading phases, respectively.Master of Science
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Gorman, Jacob Adrian John. "Economic feasibilty of utilizing saline groundwater of West Alabama to produce Florida pompano in a recirculating aquaculture system." Auburn, Ala, 2009. http://hdl.handle.net/10415/1692.
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Johnson, William P. "An investigation of the effects of ozone in a recirculating aquacultural production system." Thesis, Virginia Tech, 1991. http://hdl.handle.net/10919/41914.
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The use of ozone in a recirculating aquacultural
production system on a commercial scale was investigated.
ozonation was responsible for statistically significant
differences in all test parameters, including: heterotrophic
plate count, total coliforms, fecal coliforms, total solids,
and total volatile solids. Results indicated ozone had a
significantly positive effect in the recirculating
aquacultural production system. Further study is
recommended, however, to better understand the effects of
ozone and to justify economically the use of ozone in
commercial systems.
Master of Science
13
Holliman, James Bret Adrian John. "An economic analysis of integrating hydroponic tomato production into an indoor recirculating aquacultural production system." Auburn, Ala., 2006. http://repo.lib.auburn.edu/2006%20Fall/Theses/HOLLIMAN_JAMES_4.pdf.
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Easter, Christopher. "Water chemistry characterization and component performance of a recirculating aquaculture system producing hybrid striped bass." Thesis, This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-10102009-020254/.
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Mccarthy, Brian. "Modeling Nitrogen Transformations in a Pilot Scale Marine Integrated Aquaculture System." Scholar Commons, 2013. http://scholarcommons.usf.edu/etd/4725.
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Integrated aquaculture systems (IAS) are a type of recirculating aquaculture systems (RAS) where the wastewater is treated and returned to the fish tanks. The important difference between the two is that in an IAS, wastes from the aquaculture component are recovered as fertilizer to produce an agricultural product whereas in an RAS, waste organics, nutrients and solids are treated and discharged. A pilot marine IAS at Mote Aquaculture Research Park in Sarasota, FL was studied for this project. Water quality monitoring, measurements of fish health and growth rates of fish and plants were performed over a two-year period to determine the effectiveness of the system in producing fish and plant products and removing pollutants. The goal of this portion of the project was to develop, calibrate and evaluate a model of the system, to understand the nitrogen transformations within the Mote IAS and to investigate other potential configurations of the Mote IAS.
The model was divided into the various compartments to simulate each stage of the system, which included fish tanks, a drum filter for solids removal, and moving bed bioreactor (MBBR) for nitrification and disinfection. A solids tank after the drum filter was used to store the drum filter effluent slurry, which was then divided between three treatment processes: a geotube, a sand filter followed by a plant bed, and a plant bed alone. Nitrogen species modeled were particulate organic nitrogen (PON), dissolved organic nitrogen (DON), ammonium and nitrate. Of the physical components of the IAS, models of the MBBR and the two plant raceways included physical, chemical and biological nitrogen transformation processes. The sand filter, solids tank and geotube models were simple mass balances, incorporating factional removals of each species based on the observed data. Other variables modeled included temperature, dissolved oxygen, volatile suspended solids and chemical oxygen demand concentrations. The model was built in a computer program, STELLATM, to simulate the Mote IAS.
The model calibration involved experimental, literature and calibrated parameters. Parameters were adjusted until the model's output was a best fit to the observed data by minimizing the sum of the squared residuals. During the sensitivity analysis, two model parameters caused large variations in the model output. The denitrifier constant caused the most variation to the model's output followed by the denitrifier fraction of volatile suspended solids.
Of the removal processes, denitrification was the largest nitrogen removal mechanism from the model, accounting for 59% and 55% of the nitrogen removed from the south and north plant raceways respectively. Plant and soil uptake represented only 0.2% of the overall nitrogen removal processes followed by 0.1% by sedimentation.
Finally, the model was used to investigate other treatment designs if the Mote IAS was redesigned. The first option involved a geotube and one plant raceway in series to treat the solid waste while the second option did not have a geotube, but two plant raceways. The first option was the most effective at removing nitrogen while the second was as effective as the original system and would cost less.
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David, Christopher Graham. "Assessment of stress and growth of the eel Anguilla anguilla in a closed recirculating aquaculture system." Thesis, University of St Andrews, 1997. http://hdl.handle.net/10023/14935.
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1) Closed recirculating intensive aquaculture potentially offers major advantages over existing technologies including reduction in normal production time, reduced water input and output and beneficial environmental effects. 2) The major aim of this study was to produce a basic scientific understanding of the factors that affect intensive recirculating culture of the European eel Anguilla anguilla in order to increase efficiency and economic viability of eel aquaculture in the E.U. 3) Unlike some intensively farmed fish such as salmonids little is known of the stress factors affecting optimal growth rates in intensive eel culture. The primary effects of stress are mediated by corticosteroids and catecholamines which may have profound effects on growth, appetite and ion and water balance. 4) Growth rates of the eel Anguilla anguilla were investigated in closed water recirculating systems utilising fresh water or saline water (12 ppt)at 23°C. Eels were initially graded into two similar populations consisting of three categories, small (12g), medium (24g) and large (48g) based on initial growth rates. 5) During a 300 day period the medium and large group's growth rates were significantly greater in 12 ppt saline water than in fresh water, although for the small fish group there was no such difference. Stocking densities were maintained at commercial levels of approximately 30-100 kg/m3. 6) Plasma cortisol concentrations increased throughout the growth period in both fresh and saline water, although there were no significant differences between the two groups during the experiment. Metabolic clearance rates of cortisol were however consistently higher in saline water fish. 7) Both groups showed an increase in plasma glucose concentration throughout the experiment. However there were no significant differences between fresh water and saline water fish for plasma concentrations of glucose, free fatty acids or lactate. 8) Eels held at stocking densities of 130 kg/m3 continued to grow in the saline water whereas the control fish in fresh water ceased growing. The results suggest that maintaining water salinity at 12 ppt in closed recirculating aquaculture systems produces increased growth rates and possibly increased efficiency of food conversion. 9) In response to acute grading stress, plasma osmolality and glucose concentrations were elevated in both fresh and salt water groups 20 minutes after grading but returned to pre-grading values within 90 minutes. Plasma cortisol concentrations were elevated after 20 and 40 minutes in saline water but returned to control values after 90 minutes. In fresh water fish, plasma cortisol concentrations were elevated after 20 minutes and remained elevated throughout the experiment. 10) Acute netting stress (tank transfer) resulted in a transient increase in plasma osmolality within 20 minutes after net transfer. Plasma cortisol concentrations were significantly elevated after 20 minutes in saline water but returned to control values after 60'minutes. In fresh water fish, plasma cortisol concentrations were elevated throughout the 90 minute period monitored after net transfer. 11) In both cases of acute stress (netting and grading), plasma catecholamines were elevated within a five minute period after the stressor was applied. This study has developed techniques to assess both long-term and short-term stress in eels and has optimised the environmental conditions leading to improved growth rates. Improvements in the performance of recirculating aquaculture for on-growing eels have been demonstrated and suggestions for future possible improvements as a way forward in commercial aquaculture have been suggested. These factors will, hopefully, lead to increased economic efficiency and increased profits in eel aquaculture within the E.U.
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King, Robin K. "The Presence of Pathogenic Bacteria in Recirculating Aquaculture System Biofilms and their Response to Various Sanitizers." Diss., Virginia Tech, 2001. http://hdl.handle.net/10919/27185.
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Recirculating aquaculture offers a prospect for successful fish farming, but this form of aquaculture presents a great potential for pathogenic microorganisms to become established in the system through the formation of biofilms. Biofilms are capable of forming on all aquaculture system components, incorporating the various microflora present in the water. Pathogenic microorganisms released from the biofilms are capable of causing recurring exposure to disease in both fish and humans. With the increased consumption of raw and rare fish, the presence of these bacteria in or on the fish could lead to ingestion of pathogens. There is also the possibility of cross-contamination during processing. The objectives of this study were to increase the understanding of pathogen incorporation into biofilms in recirculating aquaculture systems and to determine the effectiveness of various sanitizers in eliminating biofilms.
Seven freshwater and two saltwater facilities were sampled, with eight different types of materials tested. Pathogenic bacteria were identified using Bacteriological Analytical Manual methods and rapid commercial test kits. Most of the pathogenic bacteria identified were opportunistic organisms ubiquitous in an aquatic environment. The most significant human pathogens were Bacillus cereus, the Shigella species and the Vibrio species. The major piscine pathogens of concern were Photobacterium damsela, the Vibrio species, and Aeromonas hydrophila. The most significant variation in biofilm pathogens was observed between facilities and not construction material.
Buna-N rubber, polyvinyl chloride (PVC), chlorinated PVC, glass, fiberglass and stainless steel disks were suspended in 79.2 liter (20 gallon) aquariums stocked with Nile tilapia (Oreochromus niloticus). The tanks were inoculated with a known amount of green fluorescent protein (GFP) modified Escherichia coli and samples were removed on days 1,3, 7 and 15. The modified E. coli were isolated on Luria Broth Agar and plate counts were performed under ultraviolet light. There was no significant difference in the growth of the surrogate pathogen on the different materials. The GFP E. coli was isolated in the largest numbers 24 hours after inoculation of the tanks, with an approximate 1-log decrease after day 1. Days 3, 7, and 15 showed equivalent growth of the target organism.
Two sets of disks were suspended in another six 79.2 liter (20 gallon) aquariums. The tanks were inoculated with a known amount of the surrogate pathogen, GFP E. coli, and after 24 hours one set of disks was removed from each tank. The second set of disks was removed and treated by spraying with water, alkaline cleanser, sodium hypochlorite, quaternary ammonium compound, or peracetic acid. Ozone was bubbled directly into one tank to treat another set of disks. The modified E. coli were isolated and counted. Total aerobic plate counts and Enterobacteriaceae counts were performed. Statistical analysis indicated that the type of material had no significant affect on the effectiveness of the sanitizers. It was determined that sodium hypochlorite (99.4591 overall reduction) and peracetic acid (98.8461 % overall reduction) were the most effective sanitizers overall, and ozone (32.9332 % overall reduction) was the least effective.Ph. D.
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Herbst, Jennifer Lynn. "The effects of ozone treatment on chemical parameters of a recirculating aquaculture system producing hybrid striped bass." Thesis, Virginia Tech, 1994. http://hdl.handle.net/10919/40666.
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The hypothesis tested in this study is that the application of ozone to reuse aquaculture water provides more favorable conditions for hybrid striped bass at production levels. Evaluation of water quality in fish culture systems being treated with ozone was made during a production trial (1200 fish/14,OOO 1). Originally, a control and four ozonated systems with doses of 3, 13, 25, and 45 g O3/kg feed/day supported fish for experimentation but, due to mechanical failure, only the control, the 13 and 25 g O3/kg feed/day treatments completed the full 35 week study. On an equal feeding basis, concentrations of dissolved organic carbon (DOC), carbonaceous biochemical oxygen demand (CBODs), and chemical oxygen demand (COD) were lowest in the most heavily ozonated systems. Ozone increased the biodegradation of DOC. Total suspended solids, particle size and distributions were impacted by ozone's flocculating properties. The percentages of particles in the smallest size range, 5-20 microns, were greater in the control system than the ozonated systems during weeks of equal feeding rates. When feeding rates differed, the control system maintained a larger number total particles per kilogram of feed administered. The pH of the ozonated systems was lower than the control which favored the ionized (less toxic) form of ammonia. Enhanced biodegradation of organics in the ozonated systems may have increased carbon dioxide production and caused a decline in pH. Greater nitrification in the ozonated systems may have also decreased the pH. Higher total ammonia nitrogen (TAN) levels were produced in the control on an equal feeding basis. Average weekly TAN t unionized ammonia (NH3), nitrite and nitrate concentrations remained at acceptable levels across treatments and throughout the production trial. Overall, the major indication of improved system conditions due to ozone treatment was that fish raised in the ozonated systems fed steadily throughout the growth trial while the control system's culture experienced periods of reduced feeding.Master of Science
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Lakeh, Amir Abbas Bazyar. "Effect of low frequency ultrasound and ultraviolet-C light for water disinfection in recirculating aquaculture systems." Doctoral thesis, Humboldt-Universität zu Berlin, Lebenswissenschaftliche Fakultät, 2015. http://dx.doi.org/10.18452/17146.
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In der Aquakultur sind Kreislaufanlagen ein umweltfreundliches und wassersparendes Produktionsverfahren. Hohe Besatzdichten und das Prinzip der Wasserführung im Kreislauf führen jedoch auch zu einem erhöhten Risiko von Infektionskrankheiten. In dem hier beschriebenen Projekt wurde untersucht, wie sich niederfrequenter Ultraschall (nf-US) in Kombination mit der in der Aquakultur bewährten UV-C Bestrahlung zur Kontrolle von Pathogenen einsetzen lässt. Es wurden vergleichende Untersuchungen zur Effizienz von nf-US, UV-C und deren Kombination gegen prokaryotische und eukaryotische Modellorganismen durchgeführt. Während sich UV-C als sehr effektiv gegen Bakterien erwies, konnte die Gesamtkeimzahl mit nf-US nicht reduziert werden. Eine Vorbehandlung des Wassers mit nf-US verringerte jedoch die mittlere Größe der im Wasser suspendierten Partikel und konnte so die Effektivität von UV-C zur Inaktivierung von Bakterien verbessern. Zur Abtötung eukaryotioscher Organismen wird eine deutlich höhere UV-Dosis als zur Kontrolle von Bakterien benötigt. Eine starke Erhöhung der UV-C Dosis ist jedoch durch die dann mögliche photo-induzierte Bildung von Nitrit aus Nitrat limitiert. Alternativ könnte nf-US zur Abtötung eukariotischer Parasiten verwendet werden. Unterschiedlichen Organismen unterscheiden sich stark in ihrer Empfindlichkeit gegenüber nf-US, wobei sich die dosisabhängige Abtötung sehr gut mit Funktionen einer exponentiellen Abnahme beschreiben lässt. Die toxikologische Untersuchung des mit UV-C und/oder nf-US behandelten Wassers mit dem Fischeitest und dem Leuchtbakterientest ergab keinen Hinweis auf die Bildung toxischer Nebenprodukte. Diese Studie zeigt, dass nf-US mit Dosen, die gegen eine Vielzahl an Parasiten wie Ciliaten, Nematoden und Crustaceen wirksam sind, sicher eingesetzt werden kann. Die Kombination von nf-US und UV-C könnte ein geeignetes Verfahren sein, um alle relevanten Pathogene in Kreislaufanlagen zu kontrollieren.Recirculating aquaculture systems are well-known as environmentally friendly and high water-efficient production systems. The high stocking densities and low water exchange leads to an increased risk of infectious diseases. In this project the combination of low frequency ultrasound (LFUS) with ultraviolet-C (UV-C) light for the control of pathogens was studied. A comparative study about the efficiency of LFUS, UV-C and their combination against prokaryotic and eukaryotic model organisms was performed. Against bacteria, the application of UV-C was very effective, while the application of LFUS was not effective. However, a pretreatment of the water with LFUS decreased the average size of the suspended particles and improved the bactericidal effect of UV-C light. Compared to the low bactericidal dose of UV-C, a much higher UV-C dose was required for inactivation of eukaryotic model organisms. A significant increase of UV-C dose, however, can be limited by the possible photo-induced formation of nitrite from nitrate. Alternatively, LFUS can be used to kill eukaryotic parasites. However, the efficiency of LFUS differed greatly between species and can be well described by functions of an exponential decay. The evaluation of whole effluent toxicity by using the fish egg test and luminescent bacteria test revealed no evidence of toxic disinfection by-products formation during UV-C irradiation and/or LFUS sonication. This study shows that LFUS can be applied safely at energy densities that are effective against a wide range of eukaryotic parasites like ciliates, nematodes and crustaceans. The combination of LFUS and UV-C could provide an appropriate water treatment with respect to all relevant pathogens in recirculating aquaculture systems.
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Stiller, Kevin Torben [Verfasser]. "The technical development and application of a recirculating aquaculture respirometer system (RARS) for fish metabolism studies / Kevin Torben Stiller." Kiel : Universitätsbibliothek Kiel, 2016. http://d-nb.info/1102933147/34.
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Brazil, Brian Ligar. "Impact of Ozonation on System Performance and Growth Characteristics of Hybrid Striped Bass (Morone chrysops (f) x Morone saxatilis (m)) Reared in Recirculating Aquaculture Systems." Diss., Virginia Tech, 1997. http://hdl.handle.net/10919/30379.
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This study was conducted to evaluate the impact of sustained ozone dosages rates (0, 3, 13, 25, and 45 g O3 per kg feed delivered per day)on water quality profile, fish physiology, and growth during a production cycle of hybrid striped bass reared in pilot scale recirculating systems. Nitrogenous wastes and dissolved organic compounds increased linearly (p < 0.01) throughout the trial under both ozonated and unozonated conditions. Ozone treatments 13 and 25 g O3 / kg feed received 170 kg more feed than the control treatment (0 g O3 / kg feed) by the end of trial. The ozonated system received an average 1 kg more feed per day than did the unozonated system, although the unozonated system received 25% more freshwater during the trial. Ozonation increased nitrification efficiency which resulted in a 25% reduction in residual ammonia measured per kilogram of feed delivered.
Biologically degradable organics (CBOD5) were lowered 45% under ozonation when adjusted for daily feed input. Microbial activity as determined by the rate of degradation of DOC was 43% higher in the ozonated environments. Increased environmental quality provided through ozonation did not result in measurable physiological improvements (p 0.05). All parameters monitored except plasma protein and hematocrit values varied significantly (p>0.05) over time. Hemoglobin, plasma protein, and hematocrit values in fish under all rearing conditions were 10.2 ± 0.4 g/dL, 7.1± 0.6 g/dL, and 52.9 ± 1.9%, respectively. Final mean serum chloride level of 115.8 ± 3.4 mE/L and mean glucose level of 186.3 ± 2.1 mg/dL were measured in fish reared at treatments 0, 13, and 25 g O3. Fish reared under ozonated conditions possessed an overall mean growth rate of 2.3 g/day and FCR of 1.58:1. Simultaneously, fish in the unozonated environment gained 1.8 g/day at an FCR of 1.90:1. At the conclusion of the trial, the final mean weight (443 ± 11.6 g) of fish reared in the unozonated environment was significantly lower (p<0.01) than fish reared in the ozone treatments 13, and 25 g O3 (combined mean of 576.6 ±16.4 g).Ph. D.
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Mair, Rachel Alice. "A suitable diet and culture system for rearing juvenile freshwater mussels at White Sulphur Springs National Fish Hatchery, West Virginia." Thesis, Virginia Tech, 2013. http://hdl.handle.net/10919/23153.
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Propagation and culture has been accepted as an approved aquaculture method for resource managers to enhance and recover freshwater mussel populations. Although juveniles can be produced readily for many mussel species, achieving high growth and survival in the laboratory remains difficult. The goal of my project was to improve growth and survival of juvenile mussels by comparing diets, algae concentration, and culture systems.
The first objective determined a suitable diet for feeding juvenile northern riffleshell, Epioblasma torulosa rangiana, a species listed as federally endangered. Three algal diets were evaluated to determine differences in growth and survival of juveniles of E. t. rangiana. After 60 d, mean survival on Phytofeast, Shellfish Diet, and WSSNFH mix were 75.1 (95% CI: 72.2 to 78.0), 78.9 (95% CI: 74.5 to 83.2), and 85.0 (95% CI: 80.6 to 89.3) percent, respectively. WSSNFH mix had the highest survival which was significantly different from Phytofeast (p=0.01). Mean shell lengths were 2.37 mm (95% CI: 2.27 to 2.47), 2.62 mm (95% CI: 2.52 to 2.72), and 3.11 mm (95% CI: 3.01 to 3.22), respectively. Juvenile length on all three diet treatments was significantly different from each other (p<0.0001), with the WSSNFH mix exhibiting the highest growth, and Phytofeast with the lowest growth.
My second objective evaluated the effect of algal concentration (cells mL-1) on growth and survival of juveniles of E. t. rangiana and mucket, Actinonaias ligamentina. After 60 d, mean survival of E. t. rangiana for the low (30,000 cells mL-1), medium (80,000 cells mL-1), and high (140,000 cells mL-1) algal concentrations were 39.1 (95% CI: 30.7 to 47.4), 20.7 (95% CI: 12.8 to 28.6), and 12.7 (95% CI: 4.82 to 20.5) percent, respectively (p<0.01). Mean shell lengths were 1.58 mm (95% CI: 1.49 to 1.66), 1.30 mm (95% CI: 1.19 to 1.40), and 1.01 mm (95% CI: 0.936 to 1.08), respectively (p<0.0001). Mean survival of A. ligamentina for the low, medium, and high algae concentrations were 46.8 (95% CI: 35.2 to 58.4), 24.6 (95% CI: 15.1 to 34.0), and 10.7 (95% CI: 5.45 to 15.9) percent, respectively (p<0.01). Significant differences were observed between the low feed concentration versus the medium and high feed concentrations. Mean shell lengths for the low, medium, and high concentrations were 1.15 mm (95% CI: 1.08 to 1.22), 0.994 mm (95% CI: 0.930 to 1.06), and 0.833 mm (95% CI: 0.770 to 0.896), respectively. All concentrations were significantly different, and the low concentration had the highest mean shell length (p<0.0001). The third objective compared the performance of three recirculating aquaculture systems for rearing juvenile mussels >5 mm. Mean incremental length of juveniles of E. t. rangiana at 60 d in Pans, Buckets, and Upwellers was 1.19 mm (95% CI: 0.746 to 1.62), 1.05 mm (95% CI: 0.608 to 1.49), and 2.07 mm (95% CI: 1.63 to 2.51), respectively. Incremental lengths were significantly higher in the Upwellers (p=0.03). The mean lengths for Bucket and Pan systems were not significantly different from each other (p=0.54). Percent survival of juveniles for the Pans, Buckets, and Upwellers were 91.7 (95% CI: 87.4 to 96.0), 90.0 (95% CI: 80.6 to 99.4), and 100 (95% CI: 100 to 100), respectively. Survival in the Upwellers was significantly higher than in the Buckets
(p=0.018). Survival of juveniles in the Pan system and Upwellers were not significantly different from each other (p=0.05). Mean growth for A. ligamentina was 1.96 mm (95% CI: 1.03 to 2.9), 0.88 mm (95% CI: 0.048 to 1.80), and 2.46 mm (95% CI: 1.537 to 3.38), respectively (p=0.07). Mean percent survival of juveniles of Actinonaias ligamentina in the Pans, Buckets, and Upwellers were 100 (95% CI: 100 to 100), 86.7 (95% CI: 74.0 to 99.4), and 100 (95% CI: 100 to 100), respectively. Survival of A. ligamentina in the Upwellers was significantly higher than in Buckets (p<0.0001). Juvenile survival in the Pan system and Upwellers was not significantly different (p=0.998). Results indicate that the Upweller culture system supported the highest growth and survival in culturing E. t. rangiana and A. ligamentina.
Master of Science
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Maigual, Enriquez Yemall Alexander. "Utilização de reator aeróbio de leito fluidizado com circulação em tubos concêntricos no tratamento de águas residuarias da produção intensiva de tilapia com recirculação da água tratada /." Ilha Solteira : [s.n.], 2011. http://hdl.handle.net/11449/99881.
Full textAbstract:
Orientador: Tsunao MatsumotoBanca: Alexandre Ninhaus Silveira
Banca: Katt Reginal Lapa
Resumo: Sistemas de Recirculação para Aquicultura (SRA) possibilitam um meio alternativo de produção de peixes para áreas com limitada disponibilidade de água. Estes sistemas de cultivo intensivo de peixes oferecem potencial de produção em pequena escala assim como em grande escala, devido a recuperação de efluentes e a reutilização da água, produzindo volumes relativamente pequenos de resíduos líquidos e sólidos. O objetivo deste estudo foi determinar a eficácia do tratamento de águas residuárias em relação à remoção de Nitrogênio Amoniacal Total (NAT), Sólidos Totais (ST), Sólidos Suspensos Totais (SST), Demanda Química de Oxigênio (DQO) e Demanda Bioquímica de Oxigênio (DBO5), Nitrogênio total (NT) e Fósforo Total (FT). Para tanto, foram introduzidos Tilápia do Nilo (Oreochromis niloticus), com 0,323kg de peso médio inicial e 17 kg m-3 de densidade de armazenamento inicial no SRA experimental. O SRA era composto de 03 tanques de plástico com capacidade de 0,20 m3, Decantador de Coluna (DC), o reator de leito fluidizado aeróbio com circulação em tubos concêntricos (BAS-CT), tendo como meio de suporte a areia de diâmetro efetivo (D10) = 0,29 mm e na sequência reator de transferência de oxigênio e remoção de CO2. A eficiência na remoção do NAT no reator BAS-CT no período de aclimatação e de estabilização foi 31,0% e 35,2%, respectivamente. A remoção de ST e SST foi de 44,44% e 71,71%, respectivamente. A eficiência alcançada de remoção no SRA da DQO foi de 64,90% e de 48,01% para DBO5. Os valores médios de remoção do NT e FT no SRA foram de 25,02% e 41,05%, respectivamente. Estes resultados indicaram que o tratamento de águas residuárias de aquicultura proposto neste estudo através do BAS-CT associado ao DC tem evitado elevadas concentrações e acumulação de poluentes dentro do SRA
Abstract: Recirculating aquaculture systems (RAS) offer an alternative means of fish production for areas that to have limited water and land availability. RAS are a highly intensive fish culture systems and offer potential production units for small and large scale operations. For effluent recovery and treated water reuse, RAS produce relatively small volumes of liquid and solids wastes. The objective of this study were to determine the efficiency of the wastewater treatment with recommended to removal of Total Ammonia Nitrogen (TAN), Total Solids (TS), Total Suspended Solids (TSS), Chemical Oxygen Demand (COD) and Biochemical Oxygen Demand (BOD5), Total Nitrogen (TN) and Total Phosphorus (TP). In this study was cultivating the Nile Tilapia (Oreochromis niloticus) with 0.323kg initial average weight and 17 kg m-3 initial storage density, cultivated in RAS. The RAS was composed with 03 plastic tanks with capacity of 0.20 m3 in each, column settler (CS), aerobic fluidized bed reactor with concentric tubes circulation (BAS-CT) with sand bed support of effective diameter (D10) of 0.29 mm and oxygen transfer-CO2 removal reactor. NAT removal efficiency was in acclimation and stabilized periods in BAS-CT reactor were 31.0% and 35.2% respectively. TS and TSS removal was 44.44% and 71.71% respectively. In this RAS, the COD removal efficiency reached was 64.90% and 48.01% for BOD5. The average removal in the NT and FT in the RAS were 25.02% and 41.05% respectively. These results indicate that aquaculture wastewater treatment proposed in this study by BAS-CT associated to CS prevents high concentrations and accumulating of pollutants within the SRA
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Seemann, Uli Bernd [Verfasser], Bela H. [Akademischer Betreuer] Buck, Bela H. [Gutachter] Buck, and Christian [Gutachter] Wild. "Sustainable rearing of crayfish in a recirculating aquaculture system using the example of Astacus astacus / Uli Bernd Seemann ; Gutachter: Bela H. Buck, Christian Wild ; Betreuer: Bela H. Buck." Bremen : Staats- und Universitätsbibliothek Bremen, 2019. http://d-nb.info/1200547179/34.
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Osório, João Vasco de Carvalho. "Mucosal and physiological responses of Atlantic salmon (Salmo salar) in brackish water RAS following peracetic acid-based disinfection." Master's thesis, Universidade de Lisboa, Faculdade de Medicina Veterinária, 2020. http://hdl.handle.net/10400.5/20695.
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Dissertação de Mestrado Integrado em Medicina VeterináriaPeracetic acid (PAA), a strong oxidative disinfectant, is effective against several microorganisms at low concentrations, requires short contact time and degrades rapidly into innocuous residues, thus considered a promising option for routine disinfection in aquaculture production. However, comprehensive knowledge of the impacts of the oxidant PAA on fish health is required for its safe application. This study documented the physiological impacts of periodic PAA exposure in Atlantic salmon (Salmo salar) post-smolts reared in brackish water recirculating aquaculture system. Salmon were exposed to PAA at a concentration of 1 mg/L every 3 days over 6 weeks. Three extensive tissue samplings were conducted (before exposure, 22 and 45 days of periodic PAA exposure). In addition, a stress test was performed before exposure and 45 days post-exposure to assess the effects of periodic exposure during a secondary stress encounter. There was no clear pattern on the changes in plasma stress parameters throughout the exposure trial, except with the glucose level, which significantly decreased over time. Oxidative stress was likely triggered by periodic oxidant exposure, as indicated by the documented significant increase in plasma antioxidants. PAA-induced expression of genes encoding for antioxidants, cytokines, heat shock proteins and mucins demonstrated a tissue-specific pattern: downregulation was observed in the gills and olfactory rosette, upregulation occurred in the skin, and no changes in the liver. Periodic oxidant exposure resulted in histological changes in key mucosal organs (olfactory rosette, skin and gills); pathological alterations were predominant in the gills where cases of epithelial lifting, hypertrophy, hyperplasia and lamellar clubbing were the most commonly identified. Lastly, periodic oxidant exposure did not alter the ability of salmon to mount robust physiological stress responses to a secondary stressor. Collectively, the present study demonstrated that periodic PAA exposure constituted an environmental stressor for which salmon were capable of mounting adaptive responses, both at the systemic and mucosal levels. In addition, periodic PAA exposure promoted the maintenance of stable microbiological water quality and did not affect the biofilter performance. The consequences of this disinfection protocol underscored the potential of PAA as a routine oxidant-based disinfection in salmon RAS production.
RESUMO - O ácido paracético (PAA), um desinfetante com fortes propriedades oxidantes, é eficaz contra diversos microrganismos a baixas concentrações, requer um curto tempo de contacto e degrada-se rapidamente em resíduos inócuos, sendo, portanto, considerado uma alternativa promissora para a desinfeção de rotina em aquacultura. No entanto, é necessário um extenso conhecimento relativo aos impactos do PAA na saúde dos peixes para garantir a sua utilização segura. Este estudo documentou as consequências fisiológicas da exposição periódica ao PAA em Salmão do Atlântico (Salmo salar) na fase “post-smolt”, produzido num sistema de recirculação em aquacultura (RAS) de água salobra. Os peixes foram expostos ao PAA a uma concentração de 1 mg/L a cada 3 dias durante 6 semanas. Foram realizadas três recolhas extensivas de tecidos (antes da exposição, e aos dias 22 e 45 de exposição periódica). Além disso, foi realizado um desafio de stress antes do início de exposição e no dia 45 de exposição para avaliar os efeitos da exposição periódica na resposta a um estímulo secundário de stress. Durante o estudo não foi observado nenhum padrão óbvio na evolução dos parâmetros plasmáticos de stress, excetuando os níveis de glucose, que desceram significativamente ao longo do tempo. O stress oxidativo foi induzido provavelmente pela exposição periódica ao oxidante, tal como indicado pelo aumento nos níveis de antioxidantes plasmáticos. A expressão dos genes que codificam antioxidantes, citoquinas, proteínas de choque térmico e mucinas revelou que existe um padrão tecidular específico em resposta ao PAA: foi registado um padrão de inibição nas brânquias e na roseta olfatória, um padrão de indução na pele, enquanto no fígado não foram registadas alterações. A exposição ao PAA provocou alterações histológicas nas brânquias, pele e roseta olfatória, sendo as alterações predominantemente observadas nas brânquias, onde as alterações mais comuns foram casos de edema epitelial, hipertrofia, hiperplasia e “lamelar clubbing”. A exposição periódica ao PAA não afetou a capacidade do salmão para estabelecer uma resposta fisiológica eficiente na presença de um estímulo indutor de stress. De forma geral, este estudo demonstrou que a exposição periódica ao PAA constituiu um estímulo stressante para o qual os peixes foram capazes de apresentar respostas adaptativas, tanto a nível sistémico como nas mucosas. Além disso, a exposição ao PAA promoveu a manutenção da qualidade microbiológica da água e não afetou a performance do biofiltro. As respostas observadas neste protocolo de desinfeção destacam o potencial do PAA como um desinfetante de rotina na produção de salmão em RAS.
N/A
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Leal, Margarida Meneses. "Effect of alternative fish feed and electricity independent oxygenation in decoupled aquaponic systems." Master's thesis, Universidade de Lisboa, Faculdade de Medicina Veterinária, 2022. http://hdl.handle.net/10400.5/23561.
Full textAbstract:
Dissertação de Mestrado Integrado em Medicina VeterináriaAquaponic systems combine Recirculating Aquaculture Systems (RAS) and hydroponic systems, combining the production of animal protein and plants. RAS wastewater enriched in nutrients is used by plants in hydroponic units. RAS rely on fishmeal and fish oil, which are finite resources as aquafeed ingredients, but alternative and more sustainable ingredients have been developed; black soldier fly (Hermetia Illucens) meal is one of the most promising alternatives. Therefore, the aim of experiment 1 was to investigate if using a fishmeal based diet (FIM) or, alternatively, a black solider fly meal based diet (BSF) has different effects on lettuce growth in decoupled aquaponic systems. Three different treatments were applied: one hydroponic treatment (control treatment); and two aquaponic treatments. The nutrient solution was made with fish wastewater from a RAS fed either with fishmeal based diet (FIM treatment) or black soldier fly meal based diet (BSF treatment). Abiotic parameters of the nutrient solutions were monitored (temperature, electrical conductivity, dissolved oxygen), air temperature, relative humidity, as well as micro- and macronutrients in the nutrient solutions; and fresh weight (FW), dry weight (DW), number of leaves, water consumption and SPAD values of the lettuce. Similar lettuce yields were observed between the treatments. However, in FIM treatment, higher sodium concentrations were seen in the nutrient solution. This is the first study showing the benefits of using alternative fish diets in decoupled aquaponic systems, to avoid potentially harmful sodium levels in aquaponic nutrient solutions. Aquaponics and hydroponics can be unsustainable in areas where electricity is unavailable, expensive or unstable; thus, the experiment 2 was carried out to test an alternative method of oxygenating nutrient solutions without electricity using H2O2, and its potential effects on lettuce growth in hydroponic and aquaponic systems. Three treatments were applied: hydroponic control treatment with compressed air (H air); and two other treatments with nutrient solutions provided with a passive H2O2-supply instead of compressed air: a hydroponic treatment (H H2O2) and an aquaponic treatment (RAS H2O2). The same parameters as in experiment 1 were examined and no significant differences in terms of growth or yield were observed. Hence, it shows that this method of oxygenation is a valid alternative for setups in areas where the electrical grid is a limitation.
RESUMO - Sistemas aquapónicos combinam os sistemas de recirculação em aquacultura (RAS) e sistemas hidropónicos, combinando a produção de proteína animal e plantas. A água residual do RAS rica em nutrientes é usada por plantas nas unidades hidropónicas. RAS depende da farinha e óleo de peixe, que são recursos finitos, como ingredientes para a ração dos peixes mas, ingredientes alternativos foram desenvolvidos; a farinha de mosca soldado negra (Hermetia Illucens) é das mais promissoras. Assim, o objetivo da experiência 1 foi investigar se o uso da ração baseada em farinha de peixe (FIM) ou alternativamente, a ração baseada em farinha de mosca soldado negra (BSF), produz diferentes efeitos no crescimento da alface em sistemas aquapónicos desacoplados. Usou-se três tratamentos, um tratamento hidropónico (controlo) e dois tratamentos aquapónicos, com solução nutritiva preparada com água residual de um RAS alimentado com ração baseada em farinha de peixe, tratamento FIM, ou baseada em farinha de mosca soldado negra, tratamento BSF. Parâmetros abióticos das soluções nutritivas foram monitorizados (temperatura, condutividade elétrica, oxigénio dissolvido), temperatura do ar, humidade relativa, tal como os micro- e macronutrientes; e massa fresca, massa seca, número de folhas, consumo de água e valores SPAD das alfaces. Observou-se semelhantes produções de alface entre os tratamentos. Porém, no tratamento FIM, maiores concentrações de sódio foram encontradas na solução nutritiva. Este é o primeiro estudo que mostra os benefícios do uso de rações alternativas em sistemas aquapónicos desacoplados. A aquaponia e hidroponia podem ser insustentáveis em áeras onde a eletricidade está indisponível, cara ou instável; assim, a experiência 2 foi realizada para testar um método alternativo de oxigenação das soluções nutritivas sem uso de electricidade usando H2O2. Usou-se três tratamentos: tratamento hidropónico controlo com ar comprimido (H air); e dois tratamentos com soluções nutritivas com fornecimento passivo de H2O2 em vez de ar comprimido: um tratamento hidropónico (H H2O2) e um tratamento aquapónico (RAS H2O2). Os mesmos parâmetros da experiência 1 foram obtidos e não se observou diferenças significativas em termos de crescimento ou rendimento. Assim, demonstra que este método de oxigenação é uma alternativa válida em áreas onde a rede elétrica é instável.
N/A
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Maigual, Enriquez Yemall Alexander [UNESP]. "Utilização de reator aeróbio de leito fluidizado com circulação em tubos concêntricos no tratamento de águas residuarias da produção intensiva de tilapia com recirculação da água tratada." Universidade Estadual Paulista (UNESP), 2011. http://hdl.handle.net/11449/99881.
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Sistemas de Recirculação para Aquicultura (SRA) possibilitam um meio alternativo de produção de peixes para áreas com limitada disponibilidade de água. Estes sistemas de cultivo intensivo de peixes oferecem potencial de produção em pequena escala assim como em grande escala, devido a recuperação de efluentes e a reutilização da água, produzindo volumes relativamente pequenos de resíduos líquidos e sólidos. O objetivo deste estudo foi determinar a eficácia do tratamento de águas residuárias em relação à remoção de Nitrogênio Amoniacal Total (NAT), Sólidos Totais (ST), Sólidos Suspensos Totais (SST), Demanda Química de Oxigênio (DQO) e Demanda Bioquímica de Oxigênio (DBO5), Nitrogênio total (NT) e Fósforo Total (FT). Para tanto, foram introduzidos Tilápia do Nilo (Oreochromis niloticus), com 0,323kg de peso médio inicial e 17 kg m-3 de densidade de armazenamento inicial no SRA experimental. O SRA era composto de 03 tanques de plástico com capacidade de 0,20 m3, Decantador de Coluna (DC), o reator de leito fluidizado aeróbio com circulação em tubos concêntricos (BAS-CT), tendo como meio de suporte a areia de diâmetro efetivo (D10) = 0,29 mm e na sequência reator de transferência de oxigênio e remoção de CO2. A eficiência na remoção do NAT no reator BAS-CT no período de aclimatação e de estabilização foi 31,0% e 35,2%, respectivamente. A remoção de ST e SST foi de 44,44% e 71,71%, respectivamente. A eficiência alcançada de remoção no SRA da DQO foi de 64,90% e de 48,01% para DBO5. Os valores médios de remoção do NT e FT no SRA foram de 25,02% e 41,05%, respectivamente. Estes resultados indicaram que o tratamento de águas residuárias de aquicultura proposto neste estudo através do BAS-CT associado ao DC tem evitado elevadas concentrações e acumulação de poluentes dentro do SRA
Recirculating aquaculture systems (RAS) offer an alternative means of fish production for areas that to have limited water and land availability. RAS are a highly intensive fish culture systems and offer potential production units for small and large scale operations. For effluent recovery and treated water reuse, RAS produce relatively small volumes of liquid and solids wastes. The objective of this study were to determine the efficiency of the wastewater treatment with recommended to removal of Total Ammonia Nitrogen (TAN), Total Solids (TS), Total Suspended Solids (TSS), Chemical Oxygen Demand (COD) and Biochemical Oxygen Demand (BOD5), Total Nitrogen (TN) and Total Phosphorus (TP). In this study was cultivating the Nile Tilapia (Oreochromis niloticus) with 0.323kg initial average weight and 17 kg m-3 initial storage density, cultivated in RAS. The RAS was composed with 03 plastic tanks with capacity of 0.20 m3 in each, column settler (CS), aerobic fluidized bed reactor with concentric tubes circulation (BAS-CT) with sand bed support of effective diameter (D10) of 0.29 mm and oxygen transfer-CO2 removal reactor. NAT removal efficiency was in acclimation and stabilized periods in BAS-CT reactor were 31.0% and 35.2% respectively. TS and TSS removal was 44.44% and 71.71% respectively. In this RAS, the COD removal efficiency reached was 64.90% and 48.01% for BOD5. The average removal in the NT and FT in the RAS were 25.02% and 41.05% respectively. These results indicate that aquaculture wastewater treatment proposed in this study by BAS-CT associated to CS prevents high concentrations and accumulating of pollutants within the SRA
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Bohman, Marcus, and Per Magnusson. "Smakprofil av Tilapia (Niltilapia) : en jämförelse av vakuumförpackad Tilapia över tid." Thesis, Högskolan Kristianstad, Sektionen för lärande och miljö, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:hkr:diva-15556.
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Fler svenskar vill konsumera mer inhemskt producerad fisk. Scandinavian Aquasystems odlar och försöker introducera fisken tilapia på svenska marknaden. Tilapia är en fisk som precis börjat göra intåg i Europa men är stor runtomkring resten av världen. En smakprofil som berättar hur länge produkten är sensoriskt tjänlig kan vara av hjälp. Denna undersökning syftade till att skapa en sensorisk smakprofil för fisken tilapia och till att se hur smakprofilen förändrades vid lagring i vakuumförpackning. För att skapa smakprofilen användes metoden QDA. Resultatet gav många egenskapsord var av vissa kunde klassificeras som färskhetsrelaterade och vissa som förskämningsrelaterade. Det kunde även konstateras att färsk, odlad tilapia har en antydan av saftigare och mer mjäll textur. Vid lagring finns en möjlighet att tilapia får en intensivare smak av dy och metall, samt en intensivare doft av dy.A large amount of Swedes has a desire to consume more nationally produced fish. Scandinavian Aquasystems produces and tries to introduce tilapia into the Swedish market. As a fish, tilapia has just begun making ways into Europe but is already a big commodity around the rest of the world. In addition, a sensory profile which tells how long the product remains sensorially suitable could be of help. This study aimed to create a sensory profile and to study its inherent effects of vacuum packaging over time. In creating the sensory profile, a QDA method was used. The study resulted in a variance of different attributes which of some could be categorized as either fresh related or spoilage related. It was found that fresh, farmed tilapia carried an indication of having a juicier and more tender texture. With storage there is chance of tilapia getting a more intense flavor of mud and metal, as well as a more intense odor of mud.
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Tollervey, Alan. "Algal nutrient uptake in recirculating aquaculture systems." Thesis, Heriot-Watt University, 1985. http://hdl.handle.net/10399/1651.
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Bartelme, Ryan P. "Cultivating Ecosystems| Microbial Communities in Recirculating Aquaculture Systems." Thesis, The University of Wisconsin - Milwaukee, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10843723.
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Intensive cultivation of fish is necessary to meet future global market demands. Recirculating aquaculture systems (RAS) enable dense growth of fish, while occupying less space than traditional aquaculture farms. However, RAS often experience complications and high fish mortalities due to disease and improper waste management. In properly functioning systems, the microorganisms associated with fish (gut, scales) as well as those found in the system environment (water, component surfaces) remove waste and maintain fish health by discouraging growth of opportunistic pathogens. Previous RAS microbiome studies are small in scope, utilize coarse methods, and contain limited long-term spatial or temporal data. With advances in computation, microbial ecology, and RAS technology it is possible to test the relationship between RAS operational management practices and microbial community composition. Using the RAS at the UW-Milwaukee School of Freshwater Sciences, I used massively parallel DNA sequencing platforms, cutting-edge fluorescent microscopy, and classical molecular and microbiological methods to rigorously examine microbial community structures. Results from this dissertation advance our knowledge of aquaculture by analyzing RAS microbiota throughout the system over time; evaluate waste removal function, and track system condition correlations to pathogen blooms. These analyses will provide insight as to how environmental changes during rearing cycles affect system function and fish health. To investigate the connection of waste componentry failure to pathogen blooms, this dissertation uses Flavobacterium columnare as a model organism, since F. columnare infects fish across a myriad of freshwater systems. Genome sequencing of pathogenic F. columnare strains gives insight into the metabolic connections between fish waste and persistence of opportunistic pathogens. By better understanding the role of the microbiome in RAS, we can improve fish health, optimize waste removal, and increase yields and profits for aquaculturalists.
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Torno, Johann [Verfasser]. "Innovations for nitrate removal in recirculating aquaculture systems / Johann Torno." Kiel : Universitätsbibliothek Kiel, 2018. http://d-nb.info/117067500X/34.
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Wood, Luther G. "Modeling effects of U-tube aeration in recirculating aquaculture systems." Thesis, This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-10312009-020150/.
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Emerman, Joshua David. "Establishing the optimal salinity for rearing salmon in recirculating aquaculture systems." Thesis, University of British Columbia, 2016. http://hdl.handle.net/2429/57067.
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Aquaculture of salmon worldwide is a 15.3 billion dollar industry and the majority of fish are produced in net-pen systems in coastal waters. Recently producers have begun investigating the feasibility of moving salmon production onto land and into recirculating aquaculture systems (RAS). The major downsides to RAS are the startup and operational costs; however the ability to optimize many environmental variables to enhance growth and feed conversion, something impossible to do in net-pen systems, may help defray these otherwise prohibitive costs. Salinity may be the most important of these variables due to the metabolic cost of osmoregulation, which has been estimated to account for 5-50% of routine metabolic rate. Decreased osmoregulatory costs could result in a greater allocation of energy toward growth, thus shortening production times and improving feed conversion efficiency. To establish an optimal salinity for growth in salmon, seven replicate, 15,000 liter RAS were constructed at the University of British Columbia’s InSEAS research facility. I conducted a preliminary study to validate that each system was able to control water quality parameters and yield similar levels of growth and feed conversion in coho salmon (Oncorhynchus kisutch). I then conducted salinity trials with Atlantic (Salmo salar) and coho salmon. Fish were grown in five salinities ranging from freshwater to seawater (0, 5, 10, 20, 30 ppt) for approximately five months. Growth rates and feed conversion ratios (FCR) were measured throughout the trial. The fastest growth rate and lowest FCR in coho salmon was at 10 ppt, which is approximately isosmotic to the blood. Growth rate of coho at intermediate salinities was almost double that at 0 or 30 ppt through the first growth period. This trend was not seen during the second coho growth period, possibly due to a size-dependent or density effect. Unexpectedly, salinity had no effect on growth rate and FCR in Atlantic salmon, although growth rates were consistent with those seen in industry. This research will help further move salmon production out of the oceans and onto land, alleviating some of the environmental costs associated with salmon grown in the oceans.Science, Faculty of
Zoology, Department of
Graduate
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SIVAKUMAR, NITHIN. "Design of fish feeding mechanism for Recirculation Aquaculture System (RAS)." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-281740.
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Fish farming or Aquaculture is a growing food-producing industry to culture the fish in artificially constructed tanks. A large number of fishes are reared in tanks for 100-150 days and produce food for the population. With increasing population and declining worldwide capture fishery, Aquaculture is perceived as a potential technique to meet the ever-expanding food demand without tarnishing the aquatic food chain. However, problems which are addressed in current systems like human intervention and unused feed material inhibit the production rate. This thesis provides methods and guidelines to resolve the challenges and simplify the mechanical design aspects of storage, transportation, and control of the dispensing process, which ultimately benefits the small-scale producers and entrepreneurs. Storing and distributing the fish feed along the fluid stream involves in considering multi-disciplinary engineering calculations. The fundamental knowledge of fluid mechanics, discrete element properties and mechanical design have been found to be an effective solution for such challenges. The results of this work provide information on designing the fish feeding mechanism incorporating fluid stream particle dispensing and evaluation of components present in the system. The thesis work provides solutions that serve as a starting point for low-cost design, validation and automation of components in a feeding mechanism for aquaculture industries.Fiskodling eller vattenbruk är en växande livsmedelsproducerande industri för att odla fisk i konstgjorda tankar. Ett stort antal fiskar uppföds i tankar i 100-150 dagar och producerar mat för befolkningen. Med ökande befolkning och minskande världsfångstfiske uppfattas vattenbruk som en potentiell teknik för att möta den ständigt växande efterfrågan på livsmedel utan att skada vattenlevande livsmedelskedjan. Emellertid hämmar problem som tas upp i nuvarande system som mänsklig intervention och oanvänt foderråvara produktions hastigheten. Denna avhandling ger metoder och riktlinjer för att lösa utmaningarna och förenkla de mekaniska designaspekterna av lagring, transport och kontroll av utmatning processen, vilket i slutändan gynnar småskaliga producenter och entreprenörer. Lagring och distribution av fiskfoder längs vätskeflödet innebär att man överväger tvärvetenskapliga tekniska beräkningar. Den grundläggande kunskapen om fluidmekanik, diskreta element egenskaper och mekanisk design har visat sig vara en effektiv lösning för sådana utmaningar. Resultaten av detta arbete ger information om utformningen av fiskmatning mekanismen som innehåller vätskeflöde partikeldosering och utvärdering av komponenter som finns i systemet. Examensarbetet tillhandahåller lösningar som fungerar som utgångspunkt för lågkostnads konstruktion, validering och automatisering av komponenter i en utfodringsmekanism för vattenbruksindustrin.
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Stoneham, Tyler Robert Jeffery. "Development of Omega-3-Fatty Acid Enriched Finishing Feed and Value Added Tilapia Product." Thesis, Virginia Tech, 2016. http://hdl.handle.net/10919/81383.
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Despite being a low fat fish and consequently a low omega-3 fish, tilapia have widespread consumer acceptability due to its mild taste, cheap price and low mercury content. However some sources claim that farmed tilapia can be detrimental to human health due to high omega-6:3 ratios and low omega-3 content specifically eicosapentaenoic acid, docosapentaenoic acid, and docosahexaenoic acid. The objective of this study was to create an omega-3 enriching feed that would increase omega-3 content in tilapia and subsequently decrease the omega-6:3 ratio. An 8 week feeding trial was conducted. Tilapia were cultured in a recirculating aquaculture system on one of eight diets (control, commercial, 1, 3, 5% fish oil or 1.75, 5.26, 8.77% ALL-G-Rich (algae). Water quality, selected fish biometrics and growth performance were recorded. Fillet and rib meat tissues were collected at weeks 4 and 8, and liver and mesenteric fat tissues were collected at week 8. Fat was extracted, trans-methylated and identified as fatty acid methyl esters using gas chromatography-mass spectrometry. Docosahexaenoic acid increased in concentration in all tissues as percent fish oil and ALL-G-Rich increased in the diets with 8.77% ALL-G-Rich resulting in significantly (P<0.0001) greater concentrations in the fillet and mesenteric fat compared to all other diets after 8 weeks. The 8.77% ALL-G-Rich diet resulted in significantly (P=0.003) greater cumulative accumulation of EPA, DPA and DHA on a mg/4oz fillet basis after 4 weeks compared to control. The results of this study suggest that an ALL-G-Rich finishing feed could be produced that would result in a value added farmed tilapia fillet.Master of Science in Life Sciences
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Miranda, Mário Olindo Tallarico de. "Cultivo de surubim pintado (Pseudoplatystoma corruscans) e híbrido (P. reticulatum X P. corruscans) em sistema de recirculação de água." Universidade Federal de São Carlos, 2012. https://repositorio.ufscar.br/handle/ufscar/1786.
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Previous issue date: 2012-05-31This study aimed to test a pilot recirculating aquaculture system (RAS) and to evaluate in this system the effects of the stocking density on the production of species of surubim pintado , Pseudoplatystoma corruscans, and its hybrid with P. reticulatum regarding the effect of stocking density and water renewal rate on the hybrid production. The study lasted for 84 days. The physical and chemical conditions in the RAS was evaluated by measuring water consumption (223,6 L/kg of fish produced), temperature (25,8±0,7ºC), dissolved oxygen (5,33±0,04 mg/L O2 in the water inlet to culture tanks), pH (6,75±0,25), total alkalinity (40,0±20,6 mg/L CaCO3), carbon dioxide (16,6±6,1 mg/L CO2), total suspended solids (8,0±4,2 mg/L TSS), total ammonia nitrogen (0,18±0,10 mg/L NH3-N), nitrite (0,163±0,090 mg/L NO2-) and nitrate (58,0±9,7 mg/L NO3-). To evaluate the fish performance, two experiments were conducted simultaneously. In experiment 1, densities of 40, 80 and 120 fish.m-3 (approximately 8.5, 17 and 25.5 kg.m-3) for the pure and the hybrid lineages were tested using a 3 x 2 factorial design (three densities and two lineages). In experiment 2, only the hybrid lineage was used, and three stocking densities were tested: 20, 40 and 60 fish.m-3 (approximately 9, 18 and 27 kg.m-3) and two water renewal rates (1 L/kg.min-1 and 0,5 L/kg.min-1), using a 3 x 2 factorial design (three densities and two water renewal rates). Fish were fed with extruded food (40% crude protein) at a rate of 2.5% of the body weight per day. For both experiments, daily specific growth rate (SGR), final weight, biomass gain, final density, food conversion, final weight and dissolved oxygen levels at the tank outlet are discussed. In experiment 1, both lineages showed to be adapted to the RAS, but the hybrid lineage had a better performance than the pure lineage. In experiment 2, the highest water renewal rate resulted in a better performance, and an increase in density improved the final production.
O objetivo deste trabalho foi testar um sistema piloto de recirculação de água (SRA) e avaliar neste sistema o efeito da densidade de estocagem no cultivo de surubins puros, Pseudoplatystoma corruscans, e do seu híbrido (P. reticulatum x P. corruscans) e o efeito da densidade de estocagem e da taxa de renovação de água no cultivo do híbrido. O trabalho teve duração de 84 dias. O SRA foi avaliado através das medições de consumo de água (223,6 L/kg de peixe produzido), temperatura (25,8±0,7ºC), oxigênio dissolvido (5,33±0,04 mg/L de O2 na água de abastecimento dos tanques de cultivo), pH (6,75±0,25), alcalinidade total (40,0±20,6 mg/L CaCO3), gás carbônico (16,6±6,1 mg/L CO2), sólidos suspensos totais (8,0±4,2 mg/L SST), nitrogênio amoniacal total (0,18±0,10 mg/L NH3-N), nitrito (0,163±0,090 mg/L NO2-) e nitrato (58,0±9,7 mg/L NO3-). Para avaliação do desempenho dos peixes, foram realizados dois experimentos simultaneamente. No experimento 1 foram testadas as densidades de 40, 80 e 120 peixes/m3 (aproximadamente 8,5, 17 e 25,5 Kg/m³) para as linhagens pura e híbrida, num delineamento em fatorial 3 × 2 (três densidades e duas linhagens). No experimento 2 foi utilizada somente a linhagem híbrida, tendo sido testadas 3 densidades de estocagem, 20, 40 e 60 peixes/m3 (aproximadamente 9, 18 e 27 Kg/m³) e duas taxas de renovação de água (1 L/kg.min-1 e 0,5 L/kg.min-1), num delineamento em fatorial 3 × 2 (três densidades de estocagem e duas taxas de renovação de água). A alimentação dos peixes nos dois experimentos foi realizada com ração extrusada (40% de proteína bruta) na proporção de 2,5% da biomassa, ministrada diariamente. Para os dois experimentos foram discutidos dados de taxa de crescimento específico diária, peso final, ganho de biomassa, densidade final produzida, conversão alimentar, peso final e níveis de oxigênio dissolvido na saída dos tanques. No experimento 1, foi observado que as duas linhagens se adaptaram ao SRA, porém a linhagem híbrida teve melhor desempenho que a linhagem pura. No experimento 2, a maior taxa de renovação de água proporcionou melhor desempenho e o aumento de densidade, incrementando a produção final.
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Shank, Dale. "Evaluating carbon dioxide as a causative agent of otolith crystallization in recirculating aquaculture systems." Bowling Green State University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1603716784275007.
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Kodra, Bledar. "Risk Analysis of Tilapia Recirculating Aquaculture Systems: A Monte Carlo Simulation Approach." Thesis, Virginia Tech, 2007. http://hdl.handle.net/10919/31845.
Full textAbstract:
The purpose of this study is to modify an existing static analytical model developed for a Re-circulating Aquaculture Systems through incorporation of risk considerations to evaluate the economic viability of the system. In addition the objective of this analysis is to provide a well documented risk based analytical system so that individuals (investors/lenders) can use it to tailor the analysis to their own investment decisions—that is to collect the input data, run the model, and interpret the results. The Aquaculture Economic Cost Model (AECM) was developed by Dr. Charles Coale, Jr. and others from the department of Agricultural and Applied Economics at Virginia Tech. The AECM is a spreadsheet model that was developed to help re-circulating aquaculture producers make strategic business decisions. The model can be used by potential producers interested in investing in re-circulating aquaculture through development of a financial analysis that in turn will help them obtain funding for the enterprise. The model is also useful for current producers who want to isolate inefficient aspects of their operation. AECM model consists of three major sections which include the Data Entry, Calculations and Analysis. The first section requires that the producer conducts background research about their operation to ensure accurate calculation and analysis. The calculation section provides a great deal of information about the operation's finances, while the analysis section provides information about the operation's financial stability. While the AECM is a powerful model, it is based on single, usually mean, values for prices, costs, and input and output quantities. However, market, financial and production uncertainties result in fluctuating prices, costs and yields. An individual who is making management decisions for a re-circulating aquaculture system will be faced with some or all of these uncertainties. By adding simulation to the AECM model to account for these uncertainties individuals will be able to make better management decisions. Information of the varying likelihoods or probabilities of achieving profits will be of crucial interest to individuals who plan on entering into or modifying an existing aquaculture system. Risks associated with six variables were examined in this paper: feed cost, feed conversion, mortality rate, capital interest rate, final weight, and output price. Data for the Interest Rate and output price were obtained from the Federal Reserve System and NMFS website respectively. Expert opinion was the source of data for the other variables. After probability distributions were applied to the random variables to account for the uncertainty the model was simulated for ten thousand iterations to obtain expected returns for three years in advance that the model calculates an income statement. In addition to that, sensitivity analyses were carried out in order to inform the producer which factors are contributing the most to the profitability of the operation. In this way the producer will have a better idea as to which aspects of the operation to monitor closely and consider modifying. The analysis shows that the mean income for the three years will be negative and thus the business would be losing money. The simulated mean net incomes were: -$216,905, -$53,689, -$53,111 for year1 through year3 respectively. Sensitivity analysis confirmed that output price is by far the most significant input that makes the overall bottom line to fluctuate most. Output price was on top of the list for all the three years analyzed in this study. Feed cost and Feed conversion were the next most significant inputs. The other inputs were also significant in explaining the fluctuation of the bottom line; however both their regression and correlation coefficients were small.Master of Science
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Hall, Antar Gamble. "A Comparative Analysis of Three Biofilter Types Treating Wastewater Produced in Recirculating Aquaculture Systems." Thesis, Virginia Tech, 1999. http://hdl.handle.net/10919/30796.
Full textAbstract:
Nine recirculating systems at the Virginia Tech Aquaculture Center were placed on line and stocked with yellow perch, Perca flavescens, fingerlings. Fish were stocked at a density of approximately 455 fish m³. Biofilter types were the only factor differing among system designs and were an upflow pulsed bed bead filter, packed tower trickling filter and a rotating biological contactor (RBC). After stocking, systems were allowed to acclimate using ammonia excreted by the yellow perch. Following acclimation, a comparative analysis on biofilter performance began. To evaluate filter performance, water quality parameters tested were temperature (°C), pH, dissolved oxygen (DO), total ammonia-nitrogen (TAN), nitrite-nitrogen (NO₂⁻-N), nitrate-nitrogen (NO₃⁻-N), alkalinity (as CaCO₃), water hardness (as CaCO₃), carbonaceous biochemical oxygen demand (cBOD₃), dissolved organic carbon (DOC), and total suspended solids (TSS). Basic water quality analysis encompassed samples drawn at 8 AM. TAN mass removal analysis encompassed water quality samples drawn at 8 AM and over 24 hours. Higher TAN mass removal rates were achieved in trickling and RBC filters than in bead filters for 8 AM (0.037, 0.14, and 0.004 g/m²/d, respectively) and diurnal sample periods. Analysis of areas under mass removal curves depicted RBC filters as surface area limited. Trickling filters proved most effective at carbon dioxide stripping and pH maintenance and also effectively removed TSS from the culture water. The study did not show filter type as having a significant effect on median organic water quality parameter values.Master of Science
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Steinberg, Kathrin [Verfasser]. "Accumulating substances and their effects on pikeperch (Sander lucioperca) in recirculating aquaculture systems / Kathrin Steinberg." Kiel : Universitätsbibliothek Kiel, 2018. http://d-nb.info/1169132588/34.
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Ling, Jian. "Nitrification and the impact of organic matter in fixed-film biofilters application to recirculating aquaculture systems /." Online access for everyone, 2005. http://www.dissertations.wsu.edu/Dissertations/Fall2005/J%5FLing%5F122105.pdf.
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Sandu, Simonel Ioan. "Evaluation of ozone treatment, pilot-scale wastewater treatment plant, and nitrogen budget for Blue Ridge Aquaculture." Diss., Virginia Tech, 2003. http://hdl.handle.net/10919/11271.
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Sustainable tilapia production at Blue Ridge Aquaculture (BRA) is constrained by availability of high quality replacement water. I developed a pilot-scale wastewater treatment system to treat and reuse effluent presently discharged. An initial study was conducted to determine the response of the BRA waste stream to ozone application. Dosages of 6.9, 4.8 and 2.4 g O3 were applied for 30 minutes to 35 L of settled effluent. Optimum ozone dosage and reaction time, ozone transfer efficiency, ozone yield coefficient, degree of pollutant removal, and other ozone and water quality parameters were determined. Most results suggested that the maximum process feasibility limit for ozone contact time was approximately 9 minutes at an applied ozone concentration of 23g/m3 (6.9 g O3 dose). Formation of foam increased solids and COD removal up to three times. Poor removal or accumulation of DOC and TAN was observed, indicating the need for biological treatment following ozonation.
Next, I evaluated a pilot station treatment train including sedimentation, microscreen filtration, fluidized bed denitrification, ozonation, aerobic biological oxidation in a trickling filter, and jar-test chemical flocculation. Significant improvements were found regarding solids, COD, cBOD5, NO3--N, TKN, and turbidity. Removal of foam after ozonation improved ozonation efficacy and pollutant removal.
A nitrogen budget for the BRA facility was derived, indicating that 35% of the nitrogen applied in feed was assimilated in fish. I evaluated the possible impact of residual inorganic nitrogen forms from treated effluent upon fish in the recirculating systems. I found that less than 1% of the TAN produced would return the recovered stream, and that the existing biological contactors can remove it. Evaluation of TAN fate indicated that 84% was oxidized in biofilters, 14% was oxidized by passive nitrification, and 1% was removed by water exchange. For NO3-N, I determined that 56% was removed by passive denitrification and 44% by daily water exchange.
The pilot station design was effective for removing organics and nutrients, and can serve as the basis for scale-up for treating and reusing the entire BRA effluent stream.Ph. D.
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Hansen, Per. "Potentiell koppling mellan elektrolys och landbaseradfiskodling : En analys av behov och tillgång på syrgas och värme." Thesis, Högskolan i Gävle, Miljövetenskap, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-36512.
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Det kommer ske en stor utbyggnad av elektrolys för produktion av vätgas i Sverigeoch övriga världen. För att sänka produktionskostnaden och därmed göra vätgasenbilligare analyserar denna rapport vilket behov av syrgas och värme som en landbaserad fiskodling har, samt hur mycket syrgas och värme fiskodlingen skulle behövaköpa från en elektrolysör. Analysen visar att de arter som används i studien - tilapia(Oreochromis, Oreochromis,. Alcolapia), regnbåge (Oncorhynchus mykiss) och lax(Salmo salar) - i en odling som producerar 40 ton fisk om året skulle förbruka cirka1,16 procent av syrgasen och cirka 0,35 procent av värmen från en 3 MW PEMelektrolysör. Försäljningsvärdet av syrgasen och värmen från en 3 MW elektrolysörberäknas till cirka 695 000 SEK/år för syrgasen och cirka 1 830 000 SEK/år för värmen. Den genomsnittliga kostnaden för syrgas och värme för arterna i studien i enodling på 40 ton/år beräknas till 8900 SEK/år för syrgasen och 6400 SEK/år förvärmen i en landbaserad fiskodling.There will be a major expansion of electrolysis for production of hydrogen in Sweden and the rest of the world. To reduce production costs and thus make hydrogencheaper, this report analyzes how much oxygen and heat a fish farm consumes andtherefore would need to buy from an electrolyser. The analysis shows that the species used in the study - tilapia (Oreochromis, Oreochromis, Alcolapia), rainbow(Oncorhynchus mykiss) and salmon (Salmo salar) - in a farm that produces 40 tonsof fish per year would consume 1.16 percent of the oxygen and 0,35 percent of theheat produced from a 3 MW PEM electrolyzer. The value of the oxygen and theheat from a 3 MW electrolyser is calculated at SEK 694,939/year for the oxygenand SEK 1,829,813/year for the heat. The average cost for the species in the studyin a 40 tonne/year fish farm is calculated at SEK 8,900/year for the oxygen and SEK6,400/year for the heat in a land-based fish farm.
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Schmitz, Mark Harvey. "Comparative Growth of All-Female Versus Mixed Sex Yellow Perch (Perca flavescens) in Recirculating Aquaculture Systems." Thesis, Virginia Tech, 1999. http://hdl.handle.net/10919/42798.
Full textAbstract:
Nine, production-scale, recirculating aquaculture systems were utilized to
compare the growth parameters between all-female and mixed sex yellow perch stocks.
Each system was stocked with 455 fish m-3 and contained one of three different biofilter
types: a rotating biological contactor, a trickling filter or a bead filter. The all-female
fingerlings (S1) used were originally derived from Lake Mendota, Wisconsin. The
mixed-sex fingerlings (S2) used were originally derived from Lake Erie. Temperature
and photoperiod (23oC, 16H-L) were maintained at levels for optimal growth.
Absolute growth rates ranged from 0.27-0.48 g/day. Mean final density within
treatments was 42.8 kg/m3 and ranged from 37.2-50.2 kg/m3. The main effect of stock
did not have a significant effect on growth (p > .1). All-female treatments exhibited more
uniform growth. The main effect of filter type did have a significant effect on fish
growth (p < .01), with fish in tanks containing trickling filters exhibiting significantly
higher growth. Total feed conversion averaged 1.61 across all treatments and ranged
from 1.38-1.78. S1 treatments consumed a significantly higher percent body weight per
day than S2 treatments (p < .05).
Analysis of PIT tagged individuals revealed that the mean relative growth rate
was significantly higher in S2 individuals (513.9%) compared to S1 individuals (315.3%:
p < .01). S2 females (597.8%) grew 1.9 times faster than S1 females (315.3%: p < .01).
Within S2 individuals, females (597.8%) grew 1.5 times faster than males (395.2%: p <
.05). For all individuals, 33.6% of the variation in final weight was explained by the
variation in initial weight. Differences in the geographic strain or culture history of these
stocks may have had a larger overall effect on growth than sexual classification (all-
female or mixed sex).
Dress percentage of skin-on butterfly fillets was examined in 20 individuals per
stock and in six groups of 20 individuals per stock. Within S2 individuals, 73.7% were
female. Mean fillet yield was significantly greater in S1 individuals (47.6%) compared to
S2 individuals (43.0%: p < .01). Mean GSI in S1 individuals (1.01%) was significantly
higher than S2 individuals (0.54%: p < .05). Within S2 individuals, mean GSI was
significantly higher in females (0.70%) when compared to males (0.08%: p < .05). Fillet
yield was significantly greater in S1 groups (47.2%) compared to S2 groups (44.9%: p <
.01). Within each stock fillet yield increased with size.
The difference in fillet yield demonstrated between these stocks may be a result of
differences in strain of origin. The identification of superior yellow perch strains or
strain crosses with regard to growth rate and fillet percentage is of considerable
importance to the industry.Master of Science
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Ferreira, Catarina Isabel Almeida. "Production and application of biowaste-based adsorbents for the removal of fish anaesthetics in recirculating aquaculture systems." Doctoral thesis, Universidade de Aveiro, 2017. http://hdl.handle.net/10773/18042.
Full textAbstract:
Doutoramento em Ciências e Engenharia do AmbienteA partir de 1960 a atividade aquícola aumentou abruptamente, tornando-se o setor de produção de alimentos de maior crescimento. A implementação de sistemas de aquacultura intensiva contribuiu para esse acentuado desenvolvimento; contudo, a sua prática impõe elevados riscos relativos ao bem-estar dos peixes, tornando-os vulneráveis a doenças, stress e a condições ambientais adversas. Para o controlo do stress são utilizados anestésicos, sendo os mais comuns a tricaína, benzocaína e 2-fenoxietanol. Estes fármacos são administrados solubilizando-os na água dos tanques e, consequentemente, contaminando-a. Atualmente, as instalações de criação intensiva estão equipadas com sistemas de recirculação em aquacultura (SRA) onde a água é tratada e reciclada. Os SRAs típicos são eficazes na remoção de sólidos suspensos e no controlo do nível de carbono orgânico dissolvido e amónia mas não estão preparados para eliminar fármacos. O processo de adsorção, utilizando carvões ativados, é uma tecnologia bem documentada e eficaz na remoção de contaminantes orgânicos, incluindo fármacos, e tem sido proposta como processo de tratamento terciário em SRA; no entanto, os carvões ativados são dispendiosos. O projeto desta tese visa a produção de adsorventes alternativos, usando bioresíduos agrícolas e industriais como percursores, capazes de competir com os carvões ativados comerciais, recorrendo a técnicas simples, baratas e amigas do ambiente. O principal objetivo consiste na aplicação dos adsorventes produzidos na remoção de anestésicos veterinários em SRA. Relativamente à valorização dos resíduos testados, os resultados mostraram que os bioresíduos agrícolas (casca de Eucalipto, sementes de uva, caroços de pêssego, cascas de nozes, resíduos de azeitona e cascas de amendoim) podem competir com os carvões fósseis em aplicações de combustão (por exemplo, produção de combustível e energia). Por outro lado, os biocarvões produzidos por pirólise dos bioresíduos industriais (lamas primárias e biológicas da indústria papeleira) são adsorventes promissores, uma vez que os resultados revelaram elevadas capacidades de adsorção com bom desempenho em sistemas fechado e contínuo. Os adsorventes produzidos a partir das lamas biológicas podem ser aplicados no tratamento de águas de aquacultura intensiva com o mesmo desempenho independentemente das condições da água (temperatura, salinidade e presença de matéria orgânica e inorgânica). Sendo as lamas produzidas em larga escala, o custo associado aos percursores destes adsorventes é nulo, com a vantagem de eliminar os esforços de gestão destes resíduos. Além disso, contrariamente aos carvões ativados comerciais, o método de produção usado evita o uso de agentes químicos e permite a recuperação de energia, sendo considerado um processo amigo do ambiente. Estes factos aliados aos bons resultados obtidos na remoção de anestésicos veterinários indicam que o uso de adsorventes a partir de lamas da indústria papeleira poderá ser uma alternativa a aplicar em SRA.
The aquaculture activity has steeply increased since the 1960’s, being the fastest growing food production industry. The implementation of intensive aquaculture systems has contributed to this impressive development in the world food fish production; however, this practice imposes high risks on the welfare of fish, making them vulnerable to adverse impacts from disease, stress and also from environmental conditions. For the fishes’ stress control, anaesthetics are administered and the most commonly used are tricaine, benzocaine and 2-phenoxyethanol. These pharmaceuticals are administered by solubilization in the fish tank’s water, which, therefore, becomes contaminated. Nowadays, intensive aquaculture facilities are equipped with a recirculating aquaculture system (RAS) where the water is treated and remains in a closed circuit. A typical RAS is planned to remove suspended solids and to control dissolved organic carbon and ammonia levels but the processes used are not prepared to eliminate pharmaceuticals. The adsorption process, using activated carbons, is a well-established technology for the removal of organic contaminants, including pharmaceuticals, and it has been proposed as tertiary treatment in RASs; however, activated carbons are very expensive. The project of this thesis aims at the production of alternative adsorbents, using agricultural or industrial biowastes as precursors, by means of a simple, inexpensive and environmentally friendly production technique and capable to compete with the commercial activated carbons. The objective is the application of the produced adsorbents for the removal of fish anaesthetics from water in the RASs. A first evaluation about the valorisation of such residues showed that the agricultural biowastes (Eucalyptus bark, grape seeds, peach stones, walnut shells, olive waste and peanut shells) can compete with fossil coals in combustion applications (e.g., fuel and power generation). On the other hand, the biochars produced by the pyrolysis of the industrial biowastes (primary and biological paper mill sludge) have favourable properties to be used as adsorbents. The adsorption results revealed highest adsorption capacities using paper mill sludge-based adsorbents with good performance in both batch and continuous (fixed-bed column) systems. Also, it was observed that the biological sludge-based adsorbent can be employed in intensive aquaculture wastewater treatment with the same performance independently of the water characteristics (temperature, salinity and presence of organic and inorganic matter). Overall, these sludges are produced in large scale, therefore the cost associated with the precursor of these alternative adsorbents is null with the additional benefit of eliminating managing costs of such residues. Moreover, contrarily to commercial activated carbons, the production process used avoids the utilization of activating chemicals and allows the recovery of energy from these residues, so it may be considered an environmentally friendly process. For these reasons, and allied to the good results obtained for the removal of fish anaesthetics, the use of paper mill sludge-based adsorbents may be an alternative choice to be applied in RASs.
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Rodriguez-Gonzalez, Laura C. "Advanced Treatment Technologies for Mitigation of Nitrogen and Off-flavor Compounds in Onsite Wastewater Treatment and Recirculating Aquaculture Systems." Scholar Commons, 2017. http://scholarcommons.usf.edu/etd/6941.
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Non-point sources (NPS) of pollution are non-discernable, diffuse sources of pollution that are often difficult to localize and in turn mitigate. NPS can include stormwater runoff, agricultural/aquaculture wastes and wastes from small decentralized wastewater treatment systems, such as conventional septic systems. The mitigation of these NPS is imperative to reduce their potential detrimental effects on the water environment. This dissertation addresses novel treatment technologies for the mitigation of nutrients, particularly nitrogen, in Recirculating Aquaculture Systems (RAS) and onsite wastewater treatment systems (OWTS). The removal of trace organics limiting RAS production and water reuse were also investigated.
The first question this dissertation addressed is: Can the application of a UV-TiO2 reactor reduce the concentration of off-flavor compounds in RAS? In the UV-TiO2 reactor, spray-coated TiO2 plates were placed in an aluminum reactor and exposed to UV light. The process was applied in both a full-scale sturgeon RAS and a bench-scale RAS for the degradation of Geosmin (GSM) and 2-methylisoborneol (MIB). Improved performance on the removal of GSM and MIB was observed when the UV-TiO2 was applied as a batch reactor since it allowed for a longer treatment time without the effect of constant production of the compounds in the biological treatment processes. Treatment performance of UV-TiO2 was affected by GSM and MIB concentrations and dissolved oxygen. No harmful effects were observed on other water quality parameters when the UV-TiO2 reactor was operated as a batch or side stream process.
The second question this dissertation addressed is: Does the application of Tire-Sulfur Hybrid Adsorption Denitrification (T-SHAD) in RAS improve nutrient and off-flavor compound removal when compared to conventional heterotrophic denitrification? T-SHAD combines tire mulch as an adsorbent and sulfur oxidizing denitrification for the removal of NO3--N from the aquaculture waters. Adsorption studies showed the tire has significant adsorption capacity for the off-flavor compounds GSM and MIB but can be limited by contact time and, possibly, the presence of competing organic matter in RAS. The application of T-SHAD as an effluent polishing step in RAS with a high empty bed contact time (EBCT) of 720 min removed 96.6% of NO3--N and 69.6% of GSM. The application of T-SHAD within RAS as denitrification side treatment for NO3--N removal resulted in lower EBCT (185 min) that limited NO3--N removal to 21% and showed no significant removal of off-flavor compounds. The comparison between T-SHAD and a molasses fed heterotrophic upflow packed bed reactor (UPBR), showed no significant differences in N species concentrations as well as off-flavor compound removal. However, high production of SO42- resulted from sulfur oxidizing denitrification (SOD) processes was noted.
Hybrid Adsorption and Biological Treatment Systems (HABiTS), is composed of two biofilters in series employing ion exchange (IX) and nitrification for removal of NH4+ and tire scrap coupled with sulfur chips and oyster shells for both adsorption and SOD of NO3-. The third question addressed in this dissertation is: What IX/adsorption media best balances both ammonium removal and cost effectiveness for application in OWTS? Adsorption isotherms performed with different media materials showed that the zeolite material, clinoptilolite, was the best medium for the nitrification stage of HABiTS due to its high IX capacity for NH4+and cost. An adsorption capacity of 11.69 mg g-1 NH4+-N when in competition with other cations present in septic tank effluents was determined by the IX model fit to the data.
The cost of clinoptilolite is significantly higher than the other media materials tested. However, the high adsorption capacity would allow for low dosages that can be combined with non-adsorptive material reducing overall costs.
The fourth question this dissertation addressed is: How is the BNR process within HABiTS affected by IX? Results from side-by-side biofilter studies with HABiTS and a conventional nitrification/denitrification biofilter showed that the combined IX and nitrification in HABiTS can allow for faster startup, sustain variable loading, and achieve over 80% removal of NH4+ at a hydraulic loading rate of 0.34 m3 m-2-d-1 when compared to the conventional biofilter with 73% removal. Under lower loading rates the biological treatment was enhanced and dominated the NH4+ removal processes in both columns. The addition of a denitrification stage decreased Total Inorganic Nitrogen (TIN) by 53.54% and 40.97%, for the HABiTS treatment and the control treatment, respectively, under loading rates of 0.21 m3 m-2-d-1. Further decrease of NH4+-N loading rates results in high desorption of exchanged NH4+ in the clinoptilolite, resulting in lower TIN removal efficiencies (28.7%) when compared to the conventional control treatment (62%).
The final question addressed in this dissertation is: Does the proposed hybrid system enhance the removal of TIN in OWTS under transient loading conditions? Further studies with HABiTS and the conventional biofilter were performed to determine N removal performance on an hourly basis. It was found that the performance of HABiTS varies with daily and hourly loads, particularly when recovering from periods of very low loading to high loadings and vice versa. If recovering from low loading periods, IX is observed for HABiTS and the biofilter outperforms the conventional treatment in overall TIN removal. However, recovery from a high loading period results in release of NH4+-N stored in the clinoptilolite and increased production of NO3--N that could affect the performance of the denitrification stage.
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Kostrytsia, Anastasiia. "Bioengineering optimization and microbial characterization of elemental sulfur-fueled denitrifying biofilms Nitrate removal effectiveness of fluidized sulfur-based autotrophic denitrification biofilters for recirculating aquaculture systems (2015) Aquacultural Engineering, 68, pp. 10-18." Thesis, Paris Est, 2018. http://www.theses.fr/2018PESC2188.
Full textAbstract:
De nos jours, la croissante population humaine et les ressources en eau limitées créent une demande pour des technologies durables de traitement des eaux usées. La dénitrification autotrophe à base de soufre élémentaire (S0) synthétisée chimiquement est une biotechnologie efficace et rentable pour l'élimination des nitrates (NO3-) des eaux usées carencées en substances organiques. Cependant, les propriétés hydrophobes du S0 synthétisé chimiquement limitent son utilisation pour la dénitrification. Par conséquent, l’objectif général de ce projet est d’optimiser les performances et d’explorer les mécanismes de traitement de la dénitrification au S0 dans les systèmes de biofilms, enquêtant l'élimination de NO3- et de nitrites (NO2-), ainsi que la compréhension des communautés microbiennes associées. Pour remédier aux limites des applications de dénitrification par S0 synthétisées chimiquement, la solubilisation de S0 avant la dénitrification et la dénitritation par S0 a été étudiée dans des essais biologiques en discontinu par une approche interdisciplinaire. Plus précisément, les expériences de biocinétique ont démontré que les taux de dénitrification et de dénitritation obtenus étaient respectivement de 20,9 et 10,7 mgN/L∙d. Une analyse microbiologique a mis en évidence la présence de la famille Helicobacteraceae sur des particules S0, probablement responsables de la solubilisation S0. En outre, le modèle d'hydrolyse du S0 catalysé par des organismes microbiens et de la dénitrification en deux étapes a été développé. L'analyse de sensibilité a identifié la dominance des paramètres liés à l'hydrolyse, et a suggéré que l'hydrolyse du S0 à base de surface à catalyse microbienne est l'étape limitante pendant la dénitrification par S0 synthétisée chimiquement. La dénitrification autotrophe avec biosulfure (ADBIOS), un sous-produit de la désulfuration biologique des gaz, a été étudiée dans des essais biologiques par lots comme solution technologique alternative pour le traitement de la pollution par le NO3- dans les eaux usées. Des biocinétiques de dénitrification et de dénitritation significativement plus élevées ont été obtenues avec le biosulfure par rapport au S0 synthétisé chimiquement, avec des activités spécifiques de 223,0 mg NO3--N/g VSS·d et 339,5 mg NO2--N /g VSS·d. Les genres Thiobacillus, Moheibacter et Thermomonas dominaient la communauté microbienne ADBIOS. Enfin, ADBIOS a été étendu au niveau du bioréacteur, et deux réacteurs de biofilm à lit mobile (MBBR) en double remplis de AnoxK1 (K1) et de nouveaux supports de biofilm AnoxK Z-200 (Z-200) ont été utilisés en continu pendant 309 jours. L'effet du taux de charge en nitrates (NLR) sur les performances d'ADBIOS a été évalué en diminuant le temps de rétention hydraulique (THS) de 72 à 21 h. Les taux de dénitrification de 236 et 234 mg NO3--N/L·d ont été atteints à un THS de 24 h pour K1 et à un THS de 21 h pour le support Z-200, respectivement. D'après l'analyse de l'ARN, les mêmes microorganismes actifs, appartenant aux genres Thiobacillus, Truepera, Flavobacterium, Hyphomonas et Sphingopyxiz, dominaient les MBBR avec des porteurs K1 et Z-200, mais leur occurrence était différenteNowadays, the increasing human population and limited water resources create a demand for sustainable wastewater treatment technologies. Chemically synthesized elemental sulfur (S0)-based denitrification is an effective and cost-efficient biotechnology for nitrate (NO3-) removal from organic-deficient wastewaters. However, the hydrophobic properties of S0 constrain its utilization for denitrification. Therefore, the goal of this project is to optimize the performance and explore the treatment mechanisms of S0-fueled denitrification in biofilm systems, through the investigation of NO3- removal, and the understanding of the associated microbial communities. To address the limitation of the chemically synthesized S0-driven denitrification applications, S0 solubilization prior to S0-driven denitrification was investigated in batch bioassays. The biokinetic experiments demonstrated that the achieved denitrification and denitritation rates were 20.9 and 10.7 mg N/L∙d, respectively. Microbiological analysis detected the presence of the Helicobacteraceae family onto S0 particles, that was likely responsible for the S0 solubilization. In addition, the model of microbially-catalyzed S0 hydrolysis and subsequent two-step denitrification was developed. The sensitivity analysis identified the dominance of the hydrolysis-related parameters, and suggested that microbially-catalyzed surface-based S0 hydrolysis is the rate-limiting step during chemically synthesized S0-driven denitrification.Autotrophic denitrification with biosulfur (ADBIOS), a by-product of biological gas desulfurization, was investigated in batch bioassays as an alternative technological solution for treating NO3- pollution in wastewaters. Significantly higher denitrification and denitritation biokinetics were obtained with biosulfur compared to chemically synthesized S0, with specific activities of 223.0 mg NO3--N/g VSS·d and 339.5 mg NO2--N/g VSS·d. The Thiobacillus, Moheibacter and Thermomonas genera were dominating the ADBIOS microbial community.Two duplicate moving-bed biofilm reactors (MBBRs) with AnoxK1 (K1) and AnoxK Z-200 (Z-200) biofilm carriers were operated for 309 days. The effect of the nitrate loading rate (NLR) on the ADBIOS performance was studied by decreasing hydraulic retention time (HRT) from 72 to 21 h. The denitrification rates of 236 and 234 mg NO3--N/L·d were achieved at an HRT of 24 h for K1 and an HRT of 21 h for Z-200 carrier, respectively. Based on RNA analysis, the same active bacteria, belonging to Thiobacillus, Truepera, Flavobacterium and Hyphomonas genera, were dominating MBBRs with K1 and Z-200 carriers, but they varied in occurrence
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Hüpeden, Jennifer [Verfasser], and Eva [Akademischer Betreuer] Spieck. "Taxonomic and functional diversity of nitrifying biofilm communities in biofilters of different recirculating aquaculture systems / Jennifer Hüpeden ; Betreuer: Eva Spieck." Hamburg : Staats- und Universitätsbibliothek Hamburg, 2020. http://d-nb.info/1209676087/34.
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Nam, Koong Hansup [Verfasser], Carsten [Akademischer Betreuer] Schulz, and Eberhard [Gutachter] Hartung. "Water treatment in Recirculating Aquaculture Systems (RAS) by ultrasonically induced cavitation / Hansup Nam Koong ; Gutachter: Eberhard Hartung ; Betreuer: Carsten Schulz." Kiel : Universitätsbibliothek Kiel, 2020. http://d-nb.info/1229436286/34.
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Stobart, Michael David. "The chemistry of a new water-recirculation aquaculture system with emphasis on the influence of ozone on water quality." Thesis, Rhodes University, 1992. http://hdl.handle.net/10962/d1005087.
Full textAbstract:
Water quality changes that occur during establishment and maintenance of nitrification in two identical recirculating aquaculture systems containing rainbow trout are described. The time taken for the nitrification process to become established was 40-45 days. Mortality of fish attributed to elevated nitrite concentrations were recorded during the initial conditioning phase of the systems. Un-ionised ammonia concentrations did not attain lethal levels during this period. Nitrate concentrations accumulated slowly throughout the study, while the pH and alkalinity of the water decreased with progressive nitrification. Levels of carbon dioxide, calcium, dissolved and suspended solids remained relatively stable until the carrying capacity of the systems was increased, upon which they increased rapidly and general water quality deteriorated. Permanently elevated concentrations of ammonia and nitrite served as an indication that the carrying capacity of the systems had been exceeded. The use of ozone as a water enhancement treatment in aquaculture systems during one- and six-hour applications was also considered in this study. Ozonation significantly reduced nitrite levels at · low concentrations (0,1 - 0,15 mg/l), although they returned to pre-treatment levels within a few hours of cessation of the treatment. The formation of an unstable, intermediate product that reforms as nitrite in the absence of ozone, rather than the complete oxidation of nitrite to nitrate, is proposed. Ozonation also resulted in decreased dissolved solids, and improved the clarity and odour of the water. Ozone had no effect on ammonia concentrations (at pH > 7,0), or on nitrate or calcium levels, and did not conclusively increase the redox potential of the water. Residual ozone concentrations up to 0,04 mg/l in a sixhour treatment had no harmful effects on rainbow trout, and there were no signs of gas-bubble disease arising from supersaturation of the water with oxygen. Activated carbon filters were effective at removing residual ozone from the water after treatment. Treatment of the water with oxygen alone had no effect on nitrite concentrations.