Aquaponics might be one solution to produce food in a more sustainable way in the future. Aquaponics combines aquaculture and hydroponics in a way that the disadvantages of one system become the advantages of the other one. The nutrient rich excess water from the fish tank is used for plant growth, while the plants are used as biofilter to clean the water for the fish. Further closed loops can be created by using plant-residues, sludge and food wastes as raw materials for a biogas digester. With a combined heat and power plant (CHP) the produced methane can be used for heat and electricity production needed by the aquaponics. This report determines if such implementation can lead to reduced overall running costs and which size the aquaponics should have. As example location Sweden is chosen.It shows that the methane demand of a CHP requires a minimum size of the biogas digesters and aquaponics. In the aquaponics at least 50 t of fish have to be bread with a complementing grow bed area of 800 - 900 m2. In total the aquaponics system contains 1000 m3 water. The Energy produced by the CHP will not cover totally the energy demand of the aquaponics-system and should be complement by energy from other sources (e.g. solar cells, wind turbines) if there is no access to a stable external energy supply. Energy produced by the CHP has an average price between 1 - 2.1 kr/kWh. If no CHP is implemented, there is no minimum size required for the aquaponics- and biogas-system and the produced methane can be used for heating and cooking.

Sustainable Built Environments Senior Capstone / This capstone project compares traditional agricultural methods to those of aquaponics. Qualitative research is used to study the effectiveness of aquaponic systems and its ability to solve the financial and environmental impacts of current agricultural methods. This study looks at the environmental, financial, and health impacts of agriculture. Three case studies are used to compare an aquaponic system, aquaculture operation, and an organic farm.

Plant growth promoters (PGP) are microorganisms essential for sustainable food production systems by improving the productivity of crops and mitigating environmental impacts. Microorganisms enhance the P availability to plants by mineralizing organic P and solubilizing precipitated phosphates. This work is focused on the effect of inoculation of a commercial product containing a mixture of Bacillus spp. on hydroponically grown lettuce (Lactuca sativa) integrated with tilapia (Orechromis niloticus) aquaculture in a closed-loop system, in comparison with an untreated control. We determined plant growth and crop quality parameters to assess the efficacy of the beneficial microorganisms. A nutrient dynamics analysis was conducted to evaluate the effect of Bacillus inoculation on the changes of nutrient concentration in aquaponics solutions, as well as the phosphorus accumulation in several components (fish, plants, water and solids). We performed a plate-count assay to quantify the number microorganisms present in systems inoculated or not with the commercial Bacillus mixture. In general, nutrient dynamics was affected by the inclusion of the Bacillus mixture in the water. Systems that received the product showed faster decreases in ammonia concentration and faster increase in nitrite and nitrate concentrations than the control. The untreated aquaponics systems showed lower accumulation of phosphorus in the water than systems receiving the Bacillus mixture, which resulted in poor plant growth, low phosphorus accumulation in the leaves and low chlorophyll content. However, the mass balance analysis showed that an external source of phosphorus possibly contributed to the overall P budget in systems receiving the Bacillus mixture. The microbial plate count assay demonstrated an active microbiota in aquaponics systems receiving the treatment while untreated systems showed zero microbial counts. The Bacillus mixture used in the present study appears to have PGP properties and to affect P dynamics in aquaponics systems. However, since the product contained traces of phosphorus in its composition, further analysis will be necessary to distinguish whether the advantageous effects promoted by the Bacillus occurred as a result of a beneficial microbial activity or a fertilizing effect. (C) 2016 Elsevier B.V. All rights reserved.

The interaction between the main ions in aquaponics nutrient solutions affects chemical composition and availability of nutrients, and nutrient uptake by plant roots. This study determined the effect of pH on phosphorus (P) speciation and availability in an aquaponics nutrient solution and used Visual MINTEQ to simulate P species and P activity. In both experimental and simulated results, P availability decreased with increase in pH of aquaponics nutrient solutions. According to simulations, P binds to several cations leaving less free phosphate ions available in solution. High pH values resulted in the formation of insoluble calcium phosphate species. The study also demonstrated the importance of organic matter and alkalinity in keeping free phosphate ions in solution at high pH ranges. It is recommended though that pH in aquaponics systems is maintained at a 5.5-7.2 range for optimal availability and uptake by plants. (C) 2016 Elsevier Ltd. All rights reserved.

This report is an exploration of using aquaponics as a means to create a senior capstone design project in a K-12 setting. The relevant world issues related to food production and resource scarcity, as well as the need to integrate STEM subjects in a more interconnected way, justify this project as robust in a high school setting. The report gives details on the design and construction of a backyard aquaponic system, along with a discussion of the performance of this actual system. This experience informs the design of a curriculum for a high school engineering classroom which is presented in outline form. / text

The goal of this study was to prove that aquaponic systems can produce lettuce of equal growth and quality compared to hydroponic lettuce production and to determine the stocking density of fish required for plant growth. Aquaponics is the integration of recirculating aquaculture and hydroponic plant production. The project had four objectives. The first objective was to determine the biomass of fish required for plant growth to develop a fish to plant density ratio. The second objective was to compare lettuce grown with aquaponic water and a hydroponic solution under the same environmental conditions. The third objective was to compare the quality of lettuce grown with aquaponics water plus nutrient supplementation with a hydroponic solution. The fourth objective was to determine the nitrogen dynamics in the aquaponic system and to compare the nutrient composition of lettuce grown with aquaponics water with nutrient supplementation and hydroponic solution. It was determined that under the specified environmental conditions 5 kg m⁻³ of Nile tilapia (O. niloticus) fed 2% of their body weight daily yields on average 4.7 kg m⁻² of lettuce (L. sativa cv. Rex) in 35 days. There was no significant difference (p ≤ 0.05) in biomass or chlorophyll concentration index in lettuce (L. sativa cv. Rex) grown with aquaponics water and nutrient supplements versus a hydroponic solution. The aquaponics solution generated equal biomass and chlorophyll concentration indexes compared to the hydroponic solution. Aquaponics water plus supplementation can yield L. sativa cv. Rex with equal biomass accumulation and chlorophyll concentration indexes compared to hydroponics lettuce. Nutrients added to the aquaponics system consisted of iron, manganese, and zinc. These nutrient concentrations became depleted in the aquaponics water over time and were not replenished via the fish feed. Dolomite was added to the aquaponics system every two weeks to increase the buffering capacity of the water and maintain optimal pH levels. Aquaponics lettuce had similar nutrient composition to hydroponic lettuce. One head of L. sativa cv. Rex (176.75 ± 31.03) will assimilate approximately 5.96 grams of nitrogen (3.38% per dry gram lettuce). One kilogram of fish will yield 6.4 lettuce heads (1,128 grams) and fixate 38.13 grams of nitrogen.

Finding an alternative to fishmeal and fish oil in animal feeds has been a topic of increasing interest due to the pressures being put on the ocean’s fisheries and the increasing world demand for animal protein. An often-overlooked source of nutrients is in the form of food waste. One third of all food produced globally ends up in landfills, wasting a huge amount of nutrients and embodied energy that could otherwise be redirected towards productive use. This study investigated the feasibility of feeding Hermetia illucens, the black soldier fly larvae (BSFL), grown on urban food waste, and Lemna minor, a species of duckweed, to tilapia in a recirculating aquaponic system as a compound feed. The study compared the growth of two groups of 58 tilapia over 44 days; one group was fed commercial pellets and the other a compound feed composed of BSFL and duckweed. The group fed the commercial pellets achieved heavier weight gain than the group fed the experimental feed but both groups resulted in steady weight gain and had similar mortality rates. Feeding the experimental feed composed of BSFL and duckweed to tilapia in an aquaponics system is an effective method of diverting food waste from the landfill and further research should be done to optimize this process.

In 2007, incentives for farmers to grow nonfood bio fuel crops, increasing transportation costs, climate change, growing consumer demand and population growth caused major food shortages in the world, especially within the high famine-risk sub-Saharan Africa. The inconsistent food cultivated products in Zanzibar combined with high consumer prices suppresses the economic growth of the agricultural sector on the island. The large decrease in what once was the primary economical driver (Agriculture) left the Island only to rely on the tourism sector to enhance the economics of Zanzibar. If a successful strategy is implemented within the agricultural sector of Zanzibar, the country could revert toward becoming, once again, a place of agricultural richness. This dissertation proposes an Agricultural research and educational facility to act as a catalyst for agricultural reintegration. The agricultural history of Zanzibar and its future potential became the underlining subject of the research and development framework proposed for the Chumbuni area. The site location and the programme will function as an incubator for local small industries, local farming and micro industries that will directly assist with increasing food security on the island. The Agricultural research and educational facility is therefore to become a structure that houses a number of beneficial programmes (focused on an educational and symbiotic relationship between industry and public). Public-funding driven cycles of basic education, agricultural education, physical practice and research thus have a platform to influence and be influenced by industry. / Dissertation (MArch(Prof))--University of Pretoria, 2015. / Architecture / MArch(Prof) / Unrestricted

This project focuses on sustainable production. The monocultural large-scale agriculture and forestry contributes with great strain on nature in the form of deforestation and eutrophication. At the same time, production is a central part of rural supply, and inthe extension also for all residents of the country. Unlike the city where demand drives land prices to such an extent that it pays to build vertically, the typology of the countryside is rather characterized by the opposite. Still, the relatively low land value in the countryside is so important for the ecological and economic sustainability of the whole country. What would happen if we priced the ecological values in evaluation of rural land prices, could it also be possible to build vertically even there? With this as a starting point, I have designed a vertical aquaponic cultivation tower, which produces both vegetables and crops, but also fish and energy. The tower is clad with both solar cells and solar panels, which ensures a sustainable self-sufficient energy supply, while excess energy can also supply surrounding buildings and businesses. In this project, I have replaced a 110 ha large cultivation area with vertical cultivation towers corresponding to the same production capacity in crops but which to the surface only occupy 1.1 ha. My idea with the saved land is to allow it to return to nature, primeval forest in the long run. In addition to the obvious ecological benefits, a changed use of land can enable a place for recreation in the middle of this “tower forest”, something that the classic arable farming rarely allows to any great extent. / I detta tredje och avslutande projekt här i Alberga har jag tagit avstamp i en av demest centrala utmaningarna för landsbygden. Detta handlar om hållbar produktion.Av Sveriges totala landyta brukas idag 8 % av marken för jordbruk, att jämföramed den bebyggda ytan på 3 %. Ytterligare ca 62 % nyttjas för skogsbruk. (SCB,Markanvändningen i Sverige). Det monokulturella storskaliga jord och skogsbruketbidrar med stora påfrestningar för naturen i form av avskogning och övergödning.Samtidigt är produktionen en central del av landsbygdens försörjning, och iförlängningen även för alla landets invånare. Till skillnad från i staden där efterfrågan driver markpriser i en sådan grad att detlönar sig att bygga på höjden är landsbygdens typologi snarare kännetecknad av detmotsatta. Ändå är den relativt lågt värderade marken på landsbygden så viktig förden ekologiska och ekonomiska hållbarheten för hela landet. Vad skulle hända om viprisade in de ekologiska värdena i landsbygdens markpriser, skulle det då kunna lönasig att även där bygga på höjden? Med detta som utgångspunkt har jag utformat ett vertikalt aquaponiskt odlingstorn, som både producerar grönsaker och grödor, men även fisk och energi. Tornet är klätt med både solceller och solpaneler vilket säkerställer en hållbar självförsörjande energitillgång, samtidigt som överskott av energi även kan förse omkringliggande bebyggelse och verksamheter. I detta projekt har jag ersatt ett 110 ha stort odlingsareal med vertikala odlingstorn motsvarande samma produktionskapacitet i grödor men som till ytan bara upptar 1,1 ha. Min tanke med den bespararade marken är att tillåta den återgå till skog, urskog på lång sikt.Förutom de uppenbara ekologiska fördelarna så kan även den ändrade markanvändingenmöjliggöra en plats för rekreation mitt i odlingstornsskogen, något som det klassiskaåkerjordbruket sällan tillåter i någon större utsträckning.

Aquaponics has the potential to be a superior food production method compared to traditional agriculture through its potential for sustainability. This is particularly important in advanced aquaponic systems that integrate waste disposal (e.g., kitchen waste) and involve several steps linking waste decomposition to protein production. In such systems a success of one type of organism propagates down the food chain and may have negative impact on contribution of other organisms, which reduces system efficiency. I hypothesised that a combination of top-down and bottom-up regulations, concepts borrowed from resilient natural ecosystems, would allow to optimize environment for aquaponics systems to avoid such negative impacts. First, I conducted an experiment using simplified systems with two trophic levels only to determine productivity, resistance and resilience of the various combinations of top-down and bottom-up forces. The simple systems contained algae and Daphnia magna and were placed under a light removal disturbance to observe the abilities of these different combinations to resist and recover from a generic negative environmental impact. Next, a similar light disturbance was implemented on a large complex aquaponics system to discover if it would react differently from the smaller ones. The resistance and resilience of algae in the small systems was not found to have any relationship to predation. The resilience of algae was better at low nutrient levels compared to high ones. There was evidence that low nutrient treatments had better resistance and resilience of abiotic factors. The larger systems appeared to have inferior resistance and resilience as compared to the simple, small systems. However, a time series analysis indicates that these large systems, in contrast to the simpler systems, actually improved in the amount of algae after the disturbance. New methods for accounting for this in resilience calculations are needed to eliminate potential statistical artifacts that might lead to some of my observations. / Thesis / Master of Science (MSc) / Aquaponics has the potential to be a superior food production method compared to traditional agriculture through its potential for sustainability. This is particularly important in advanced aquaponic systems that integrate waste disposal (e.g., kitchen waste) and involve several steps linking waste decomposition to protein production. In such systems a success of one type of organism propagates down the food chain and may have negative impact on contribution of other organisms, which reduces system efficiency. I hypothesised that a combination of top-down and bottom-up regulations, concepts borrowed from resilient natural ecosystems, would allow to optimize environment for aquaponics systems to avoid such negative impacts. First, I conducted an experiment using simplified systems with two trophic levels only to determine productivity, resistance and resilience of the various combinations of top-down and bottom-up forces. The simple systems contained algae and Daphnia magna and were placed under a light removal disturbance to observe the abilities of these different combinations to resist and recover from a generic negative environmental impact. Next, a similar light disturbance was implemented on a large complex aquaponics system to discover if it would react differently from the smaller ones. The resistance and resilience of algae in the small systems was not found to have any relationship to predation. The resilience of algae was better at low nutrient levels compared to high ones. There was evidence that low nutrient treatments had better resistance and resilience of abiotic factors. The larger systems appeared to have inferior resistance and resilience as compared to the simple, small systems. However, a time series analysis indicates that these large systems, in contrast to the simpler systems, actually improved in the amount of algae after the disturbance. New methods for accounting for this in resilience calculations are needed to eliminate potential statistical artifacts that might lead to some of my observations.