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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

A techno-economic feasibility study into aquaponics in South Africa

Lapere, Philippe 12 1900 (has links)
Thesis (MScEng (Industrial Engineering))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: The purpose of this study is to investigate the techno-economic feasibility of operating an aquaponics farm in South Africa. Aquaculture is the fastest-growing type of food production in the world, yet South Africa is lagging behind international efforts to boost the industry. An independent academic feasibility study on small scale aquaponics farms in South Africa has not been performed before, causing current and prospective farmers to be uncertain about the prospects of the venture. The study is approached by investigating the aquaculture and aquaponics industry and gathering the relevant information. By investigating other models used to represent aquaculture or aquaponics systems, the required information is gathered in order to build a unique model for the purpose of determining the feasibility of the case study farms. The model is modified to represent each of the case study farms. The results show that the majority of the farms are not economically viable. A sensitivity analysis provides some insight on how varying certain parameters can affect the performance of the systems. Using the information gathered in the case studies and research, a near-ideal system is specified in order to establish whether this improved system can be viable whilst taking into account the constraints placed upon aquaponics ventures in South Africa. The study suggests some recommendations for current and prospective farmers that might improve their chances of succeeding with an aquaponics venture. The study finds that currently aquaponics in South Africa is hindered by a number of constraints that result in it being a high-risk venture with meagre returns on investment. However, the study shows that if an aquaponics system were designed, built and managed correctly, it could theoretically be an economically viable venture. The investigation has, in a logical method, provided insight into the viability of operating an aquaponics farm in South Africa. / AFRIKAANSE OPSOMMING: Die doel van hierdie studie is om die lewensvatbaarheid van akwaponika in Suid-Afrika te ondersoek. Akwakultuur is die tipe voedselproduksie wat die vinnigste groei in die wêreld, maar Suid-Afrika hou nie tred met die internasionale poging om akwakultuur te ontwikkel nie. „n Onafhanklike lewensvatbaarheid studie oor kleinskaal akwaponika plase in Suid-Afrika is nog nooit onderneem nie. Dit veroorsaak dat huidige en voornemende akwaponika boere onseker is oor die uitkomste van hulle ondernemings. Die studie is benader deur die akwaponika en akwakultuur bedrywe te ondersoek, en die relevante inligting te versamel. Deur ander modelle wat gebruik word om akwakultuur en akwaponika sisteme te verteenwoordig te ondersoek, is die nodige inligting versamel om „n unieke model te bou wat gebruik word om die lewensvatbaarheid van die gevallestudies te bepaal. Die model is aangepas om elkeen van die gevallestudies te verteenwoordig. Die resultate wys dat die meerderheid van die gevallestudie plase nie ekonomies lewensvatbaar is nie. „n Sensitiwiteitsanaliese gee insig oor hoe spesifieke parameters die prestasie van die sisteme affekteer. Deur die inligting wat versamel is tydens die gevallestudies en navorsing te gebruik, kan „n sisteem gespesifiseer word om te bevestig of hierdie verbeterde sisteem lewensvatbaar kan wees terwyl dit die beperkings waaronder akwaponika sisteme in Suid Afrika geplaas word in ag neem. Die studie verskaf „n paar aanbevelings vir huidige en voornemende boere. Hierdie aanbevelings kan die kanse van sukses van die ondernemings verbeter. Die studie het gevind dat akwaponika in Suid-Afrika deur „n aantal beperkings benadeel word, wat lei tot „n situasie waar dit „n hoë-risiko onderneming is, met lae opbrengste op die belegging. Maar, die studie wys ook dat as „n sisteem korrek ontwerp, bou en bestuur word, dit teoreties „n ekonomies lewensvatbare onderneming kan wees. Die studie het op „n logiese wyse insig gegee oor die haalbaarheid van akwaponika in Suid-Afrika.
12

Application of a Floating Membrane Algal Photobioreactor for Freshwater Aquaculture

Shyu, Hsiang-Yang 29 October 2018 (has links)
As the global population grows, water and food demand also increase. The intensive aquaculture industry has helped to mitigate these problems. In order to make aquaculture sustainable, it is necessary to remove the abundant nutrients produced by fish in the water. In this study, the role of the microalga of Chlorella vulgaris in the Isolated Cultivation of Algal Resources Utilizing Selectivity (ICARUS) membrane photobioreactor was evaluated for nutrient control in the aquaculture system. The production of algal biomass, the removal rate of nutrients, and the impact of microalgae on cultured organisms were monitored during the operation of aquaculture systems. At the end of the experiment, the yield of algae in ICARUS was approximately 344 ± 11.3 mg / L. Compared to the control groups, this production of algae is considered to be low. Likely factors were insufficient indoor light intensity, membrane fouling limiting the mass transfer of nutrients, and improvements still needed for the overall ICARUS prototype design. However, ICARUS can efficiently prevent algae from contamination, and provide pure harvest production for food supplement. It was observed that algae have the ability to help stabilize pH and increase dissolved oxygen for the system. However, in high-density, mixed systems, algae may cause physical damage to fish (e.g., clogging of gills). The high ammonia concentrations produced by fish could be controlled by Chlorella vulgaris since this species of algae prefers ammonia to nitrate. In conjunction with algal growth, aquaculture systems concentration of ammonia was maintained at 0.90±0.16 mg/L. The integration of ICARUS is not only a potentially sustainable option for aquaculture, but also a multipurpose tool for other types of wastewater treatment. An economic analysis for scale-up of the ICARUS system was performed. In summary, this study aimed to develop a new commercial ICARUS photobioreactor which can serve for different types of wastewater systems with a high algal production efficiency and economic benefits.
13

Food Security and Small Scale Aquaponics: A Case Study on the Northern Mariana Island of Rota

Foskett, Dustin 14 January 2015 (has links)
Aquaponics has recently emerged on the global scene as a viable form of alternative agriculture. A combination of practices, such as growing and harvesting fish (aquaculture) along with "hydroponically" grown fruits and vegetables, aquaponics integrates traditional agriculture practices with twenty-first century scientific food producing methods. In this thesis, I analyze the literature on aquaponics and connect it firmly within the current social and environmental discussions of the food security discourse among Pacific Island Countries and Territories in order to provide a context of geographical relevance of fish and vegetable producing systems. I also provide data from the Northern Mariana Island of Rota to showcase why and how aquaponics may be a viable option for improving food security within such a context. I then argue that the aquaponic project on the island of Rota helps serve as one potential pathway to improving food security. / 2015-07-14
14

Effect of Aquaponic vs. Hydroponic Nutrient Solution, Led Light Intensity and Photoperiod on Indoor Plant Growth of Butterhead, Romaine and Kale (<i>L. Sativa, B. oleracea</i>)

Foster, Sean M 01 June 2018 (has links) (PDF)
Vertical farming has been proposed as a solution for providing food security for an increasing, urbanized human population. Light-emitting diode (LED) technology has become increasingly affordable and efficient, making it an ideal choice as artificial lighting for indoor farms. Still largely undiscovered parameters are the optimal plant varieties and types of production systems for plant growth, profit, and human nutrition. Aquaponics may be able to provide sustainable animal protein for vertical farms, increasing their ability to provide more substantial nutrition to consumers. This research aimed to better understand vertical farming as a food production system, and to determine if aquaponics can be an appropriate and applicable fit for it. The experiment was a randomized, factorial design with three independent variables: (1) LED photoperiod interval (2) LED-plant distance, and (3) nutrient solution, as well as several dependent variables to assess both plant yield and quality. A 4-tiered shelving unit was constructed for nutrient film technique (NFT) plant production, and treatments were assigned to each row: (1) LED experiment: Row A, 12/12hr reduced photoperiod with adjustable LEDs 4in. above plant surface; Row B, 2/1hr altered photoperiod interval relative to the control; Row C (control), 16/8hr “standard” photoperiod. (2) Nutrient experiment: Row C, aquaponic nutrient solution; Row H, hydroponic nutrient solution. Rows C and H had matched photoperiod and light intensity. Kale from Row A had significantly lower fresh and dry plant yield relative to the control, Row C (p<0.05). Hydroponic romaine, Row H, had significantly higher plant yield relative to aquaponics, Row C (p<0.05). Butterhead yields were not significantly different in any treatments (p>0.05). Future research may implement a larger sample size of only one plant variety, harvest plants earlier, limit light intensity variation, effectively “balance” the aquaponics system, and have more measures of plant “quality.”
15

Evaluation Of The Applications Of A Biomimetic Antifouling Surface (Sharklet™) Relative To Five Other Surfaces To Prevent Biofilm Growth In Freshwater Aquaponics Systems

Nihiser, Brice A. 11 June 2014 (has links)
No description available.
16

Life Cycle Assessment for Improving Sustainability of Aquaculture and Aquaponics

April Janai Arbour (17583837) 09 December 2023 (has links)
<p dir="ltr">Controlled environment agriculture (CEA) is a practice of food production under optimized conditions to intensify production yield, and thus has potential for addressing food security for a growing population. Aquaculture and aquaponics are two types of CEA that can produce aquatic animals along with plants using non-arable lands and lower inputs of water and nutrients. However, their operations have high energy consumption and generate considerable nutrient-rich sludge and wastewater, making their environmental performance an emerging research focus. This thesis quantitively analyzed the environmental sustainability of aquaponics and aquaculture production using life cycle assessment (LCA).</p><p dir="ltr">The LCA on aquaponics evaluated a marine aquaponics production system that grew shrimp, red orache, minutina and okahajiki, and analyzed the effect of salinity, C/N ratio, and shrimp-to-plant stocking density. The grow-out stage accounted for over 90% of total environmental impacts with electricity use as the predominant contributor. The marine aquaponic production exhibited best environmental performance when operated at low salinity (10 ppt), and high C/N ratio (15) and stocking density (5:1), which can be further improved by 95–99% via the use of wind power as electricity source. Additionally, variation in the prices of aquaponic products was found to improve the system’s environmental impacts by up to 8%.</p><p dir="ltr">The aquaculture LCA focused on shrimp recirculating aquaculture systems (RAS) and evaluated the environmental feasibility of microalgae-based wastewater treatment. Microalgae treatment effectively removed 74% of phosphate in RAS wastewater and thus reduced the freshwater eutrophication potential by 55%. However, its remediation performance was inferior to activated sludge treatment due to different operation scales. Electricity was the principal hotspot of microalgae treatment and made up over 99% of all the environmental impacts, which can be considerably decreased by reducing coal use in the electricity supply. Three utilization pathways for algal biomass (feed ingredient, biodiesel and biogas) were investigated; however, only biogas production was found to show environmental benefits to marine eutrophication remediation owing to the low biomass quantity produced.</p><p dir="ltr">While <a href="" target="_blank">aquaculture and aquaponics</a> play important roles in meeting the globally growing demand for seafood, this thesis provides valuable life cycle inventory data for these fields. Moreover, the LCA models developed in this thesis are useful decision-making tools for aquaculture and aquaponic producers to adapt farming practices with lower environmental footprint.</p>
17

Development of a simplified commercial-scale aquaponic facility for implementation in northern Uganda

Wicoff, Emily January 1900 (has links)
Master of Science / Department of Civil Engineering / Steven K. Starrett / Current aquaponic technology ranges from backyard hobbyist to technologically advanced commercial production. A single source for protein (fish) and nutrients/vitamins (vegetables), development of a technologically simplified commercial-scale system is a realistic solution for many impoverished nations. This study develops a simplified aquaponic facility to be implemented in rural northern Uganda. Research objectives were to: (1) identify simplified commercial-scale system design components, (2) establish a water quality baseline, (3) identify plant/tilapia production ratios, (4) identify construction materials available in northern Uganda, (5) integrate culturally familiar elements, (6) complete preliminary facility design, and (7) calculate facility water balance. The study established that a viable simplified design achieves: (1) water circulation with weir gravity flow and one return pump, (2) tank cleaning with strategically sloped floors and manual waste siphoning, and (3) breeding control with raised bottom fishnets. Submerged aeration is critical to optimal fish growth, and cannot be eliminated despite surface aeration’s low energy appeal. Baseline water quality parameter values of DO > 3 mg/L, pH > 5.5, and TAN > 3 mg/L (2 mg/L average) were established for the pilot study configuration and hydraulic retention time (HRT). A plant/tilapia ratio of 2.5 ft[superscript]2/lb was identified for the proposed facility’s design. The simplified design was assessed compatible with concrete block construction local to northern Uganda. Incorporating the following culturally familiar elements will facilitate technology adoption: utilize native fish (tilapia) and vegetable crops identified in community markets, replace commercially produced plant tank raft components with woven matting from locally available natural materials, and identify the unfamiliar proposed tank design with newly adopted raceway culture techniques at a well-known Ugandan national fishery institute. A proposed facility preliminary design represents local materials, identified plant/tilapia ratio, minimum HRT, and simplified design components for tilapia densities ranging from 12 to 3 gal/lb. With the facility supplied by both rainwater and groundwater, corresponding water balances for 12 to 3 gal/lb densities ranged from a 9,735 gal/yr well supply demand to a 10,984 gal/yr rainwater surplus.
18

The Case for Aquaponics: an Environmentally and Economically Superior Method of Food Production

Fankuchen, Peter A 01 January 2013 (has links)
This thesis intends to introduce the reader to the concept and benefits of aquaponic farming. The paper begins with an introductory definition of aquaponics, a brief history of aquaponic practices, and a status quo of the industry - all meant to contextualize this concept which is, to the general public, widely unknown. Comparisons are then given to competing technologies which are likely more familiar to most. Specifically, the advantages of aquaponic cultivation are weighed against traditional soil farming, hydroponics, and aquaculture. Current limitations facing the industry are discussed before the thesis concludes with an overview of arguments made.
19

Aquaponics Everywhere? An Exploration of a Growing Industry's Revolutionary Potential

Harder, Alexandra 01 January 2017 (has links)
In the summer of 2016 I worked at The Moore Street Market Farm run by Oko Farms LLC., New York City’s first and largest outdoor urban aquaponics company. Aquaponics is a method of farming that combines the cultivation of aquatic animals and plants in a mutually beneficial, symbiotic relationship. While the industry is in its infancy, aquaponics is acknowledged to have great potential to change the future of farming for sustainability, as it uses less water than traditional agriculture and can be implemented almost anywhere. This thesis examines current challenges to the industry and the potential future applications of aquaponics in urban environments, through discussion of current developments in aquaponics in Europe; Growing Power’s use of aquaponics for community benefit in the Milwaukee; as well as in the case-studies of Oko Farms and Agtech aquaponics companies in New York City. While eventually concluding that implementations of aquaponics for profit might not be viable in the long run, this thesis ends with a short discussion on hypothetical successful applications the industry could thrive in.
20

Evaluation of a pilot land-based marine integrated aquaculture system

Boxman, Suzanne 01 January 2013 (has links)
Recirculating aquaculture systems (RAS) produce aquaculture products on land with minimal discharge of waste products and minimal water loss. High costs associated with waste treatment for RAS have triggered the growth of integrated aquaculture systems (IAS) which incorporate macrophytes (aquatic plants) into the treatment train. The objective of this research was to examine a pilot scale inland marine IAS with three different methods for solids treatment: a sand filter followed by a plant bed, only a plant bed, and geotextile bags. Florida Pompano (Trachinotus carolinus) were grown along with Smooth Cordgrass (Spartina alterniflora), Black Needle Rush (Juncus romerianus), and Red Mangrove (Rhizophora mangle). Between May 2011 and April 2012, water quality was tested at seven points located throughout the IAS for total suspended solids (TSS), chemical oxygen demand (COD), total nitrogen (TN), ammonium (NH4+), nitrate (NO3-), total phosphorus (TP), and orthophosphate (PO43-) concentrations every 4 to 6 weeks. Plant and soil samples were collected three times and analyzed for total nitrogen and total phosphorus. A statistically significant difference in the effluent concentrations for the three treatments was not found; however, due to the recombination of effluent from the solid treatments and the variability inherent in a pilot scale system it was difficult to isolate the individual efficiencies of each treatment. Therefore, on average the complete system achieved COD and TSS removal efficiency of 59% and 88%, respectively and TN and TP removal efficiency of 48% and 19%, respectively. Nutrient uptake by plants did not vary significantly between the plant beds. In general, the system provided sufficient nutrient removal for safe fish production, and the fish provided enough nutrients for ample plant growth.

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