Hệ thống giám sát, cảnh báo và điều khiển tự động chất lượng nước nuôi trồng thủy sản e-AQUA là mô hình công nghệ nổi bật đang được giới thiệu tại Sàn giao dịch Công nghệ TP.HCM.
New developments in recirculating aquaculture systems in Europe – A perspective on environmental sustainability 2010
The dual objective of sustainable aquaculture, i.e., to produce food while sustaining natural resources is achieved only when production systems with a minimum ecological impact are used. Recirculating aqua- culture systems (RASs) provide opportunities to reduce water usage and to improve waste management and nutrient recycling. RAS makes intensive fish production compatible with environmental sustainability. This review aims to summarize the most recent developments within RAS that have contributed to the environmental sustainability of the European aquaculture sector. The review first shows the ongo- ing expansion of RAS production by species and country in Europe. Life cycle analysis showed that feed, fish production and waste and energy are the principal components explaining the ecological impact of RAS. Ongoing developments in RAS show two trends focusing on: (1) technical improvements within the recirculation loop and (2) recycling of nutrients through integrated farming. Both trends contributed to improvements in the environmental sustainability of RAS. Developments within the recirculation loop that are reviewed are the introduction of denitrification reactors, sludge thickening technologies and the use of ozone. New approached towards integrated systems include the incorporation of wetlands and algal controlled systems in RAS. Finally, the review identifies the key research priorities that will con- tribute to the future reduction of the ecological impact of RAS. Possible future breakthroughs in the fields of waste production and removal might further enhance the sustainabilty of fish production in RAS.
© 2010 Elsevier B.V. All rights reserved.
Energy use in Recirculating Aquaculture Systems (RAS) – A review 2013
Recirculating aquaculture systems (RAS) are increasingly being used for Atlantic salmon smolt produc- tion. However, knowledge of how the RAS environment affects welfare and performance of Atlantic salmon is limited. For instance, safe limits for chronic exposure to typical compounds in RAS, such as NH3-N, NO2-N, and CO2 should be established for Atlantic salmon, as well as their interactions with nutrition, other RAS water compounds, and the microbiota. These questions can best be answered in a research facility that is providing a RAS environment. In addition, the facility described here was required to produce 480 000 smolts annually, to provide sufficient research fish in the institution. Design and dimensioning of such a facility require attention to flexibility for various experimental designs, and the flexibility to vary specific water quality constituents, properties that are not necessary in a standard production plant. A research facility of 1754 m2 ground floor area (Nofima Centre for Recirculation in Aquaculture, NCRA), was designed and constructed for these purposes at a cost of 45 mill. NOK (2010 value). The facility included six experimental halls, a number of support rooms, and four independent RASs. Water quality requirements at maximum feed loading were in the design phase set to <10 mg/L CO2, <0.7–1 mg/L TAN, and <0.1 mg/L NO2-N, and the RASs dimensioned with this objective. The facility was designed so that water from different RAS or flow-through water sources could be chosen atthe level of the culture tanks, thus giving flexibility for experimentation. Performance of the facility was tested in two trials, during the first 3 years of operation. In Trial 1, a standard production study showed that Atlantic salmon parr reared in the facility had growth rates comparable to that seen in the Norwegian Atlantic salmon smolt industry. In Trial 2, water quality and removal efficiencies of RAS 1 were evalu-ated at increasing daily feed loads. Removal efficiencies were comparable, in the case of TAN, and when calculated for the system as a whole also for CO2, to assumptions made during dimensioning and design of the facility. The RAS maintained water quality within set limits for TAN and CO2, but not in the case of nitrite (0.22 mg/L NO2-N versus 0.1 mg/L limit). The water quality limits of TAN and CO2 were reached, not at full feed capacity, but at 134% of the theoretical feed capacity calculated prior to construction. This dimensioning was based on an often used methodology. When recalculating the RAS 1 TAN production, but now using published Atlantic salmon parr N-retention data, it was found that the methodology used prior to construction may over-estimate the TAN production by about 34%. Thus, Trial 2 was useful for recalibrating the feed load capacity of the RASs, and for accurate experimental design in future projects. It is expected that in the long-term NCRA will be useful in determining the environmental and nutritional requirements of fish reared in RAS.
© 2012 Elsevier B.V. All rights reserved.
Recent Development of High Density Recirculation Aquaculture
Recirculation aquaculture systems have the advantage of using small quantities of water, tightly controlled to maximise growth the potential of species and minimise environmental impacts. On the other hand, high initial setup costs and high risk factors are always associated with this type of operation. Also, conditions of recirculation systems change constantly by different parameters, such as growth of stocks, stock density, flow rate and feed type. Further studies of the capabilities of systems must be done in each operation to provide maximum results and profits.
Exploring recirculating aquaculture systems
Abstract: Recirculating Aquaculture Systems are becoming prevalent in the US aquaculture industry, and there are numerous advantages and disadvantages (from environmental, economical, and marketing perspectives) for using these systems. In order to be efficient, careful planning goes into the design engineering to achieve satisfactory and sustainable production levels. In this lesson, students will explore an RAS computer tutorial and navigate to examine content summarizing RAS components and descriptions. There is a digital self-test within the RAS computer tutorial to assess understanding of system components and their functions.
Students will be able to launch the RAS digital model and explore by manipulating variables (e.g., stocking densities, filtration efficiencies, feeding rates, temperature, etc.) and observing model simulation results. Through the use of this model, students will become knowledgeable about the utility of recirculating aquaculture systems (RAS) for aquaculture production, their advantages and disadvantages relative to cost, production efficiency and yield, and level of complexity. Students will be able to identify system components, their function within the integrated system, and their appropriate installation and maintenance.