Ramli Norulhuda Mohamed, Verreth J A J, Yusoff Fatimah M, Nurulhuda K, Nagao N, Verdegem Marc C J
Aquaculture and Fisheries Group, Wageningen University & Research, Wageningen, Netherlands.
Department of Biological and Agricultural Engineering, Faculty of Engineering, Universiti Putra Malaysia, Serdang, Malaysia.
Front Bioeng Biotechnol. 2020 Sep 4;8:1004. doi: 10.3389/fbioe.2020.01004. eCollection 2020.
This review investigates the performance and the feasibility of the integration of an algal reactor in recirculating aquaculture systems (RAS). The number of studies related to this topic is limited, despite the apparent benefit of algae that can assimilate part of the inorganic waste in RAS. We identified two major challenges related to algal integration in RAS: first, the practical feasibility for improving nitrogen removal performance by algae in RAS; second, the economic feasibility of integrating an algal reactor in RAS. The main factors that determine high algal nitrogen removal rates are light and hydraulic retention time (HRT). Besides these factors, nitrogen-loading rates and RAS configuration could be important to ensure algal performance in nitrogen removal. Since nitrogen removal rate by algae is determined by HRT, this will affect the size (area or volume) of the algal reactor due to the time required for nutrient uptake by algae and large surface area needed to capture enough light. Constraints related to design, space, light capture, and reactor management could incur additional cost for aquaculture production. However, the increased purification of RAS wastewater could reduce the cost of water discharge in places where this is subject to levees. We believe that an improved understanding of how to manage the algal reactor and technological advancement of culturing algae, such as improved algal reactor design and low-cost artificial light, will increase the practical and economic feasibility of algal integration in RAS, thus improving the potential of mass cultivation of algae in RAS.
本综述研究了藻类反应器集成于循环水养殖系统（RAS）中的性能及可行性。尽管藻类能同化RAS中的部分无机废物，具有明显益处，但与此主题相关的研究数量有限。我们确定了与藻类集成于RAS相关的两个主要挑战：其一，藻类在RAS中提高脱氮性能的实际可行性；其二，在RAS中集成藻类反应器的经济可行性。决定藻类高脱氮率的主要因素是光照和水力停留时间（HRT）。除这些因素外，氮负荷率和RAS配置对于确保藻类的脱氮性能可能也很重要。由于藻类的脱氮率由HRT决定，这将影响藻类反应器的尺寸（面积或体积），因为藻类吸收养分需要时间，且需要较大的表面积来捕获足够的光照。与设计、空间、光捕获和反应器管理相关的限制可能会给水产养殖生产带来额外成本。然而，RAS废水净化程度的提高可以降低在有排放限制的地方的排水成本。我们认为，更好地理解如何管理藻类反应器以及藻类培养技术的进步，如改进藻类反应器设计和低成本人工照明，将提高藻类集成于RAS的实际和经济可行性，从而提高RAS中藻类大规模培养的潜力。
