In modern agriculture, especially aquaculture, scientific introduction of nitrogen is necessary to achieve economic production and prevent environmental pollution.
Litopenaeus vannamei (L. vannamei) is an extremely important species in the aquaculture industry, providing humans with a large amount of high-quality proteins. Therefore, it is of great scientific value and practical significance to study the nitrogen budget and recovery during the cultivation process of L. vannamei.
Recently, the research team led by Prof. SUN Jianming from the Institute of Oceanology of the Chinese Academy of Sciences (IOCAS) studied the utilization, migration, transformation, and accumulation of input nitrogen in the L. vannamei recirculating aquaculture system (RAS) between aquaculture objects and each water treatment unit, and analyzed the application of Chlorella vulgaris in nitrogen recovery from RAS solid waste and aquaculture tail water.
The study was published in Journal of Water Process Engineering on Oct. 26.
In this study, researchers used a green and efficient water treatment technology called electrocoagulation (EC) to improve the performance of the L. vannamei RAS. The distribution of input nitrogen during the culture of shrimp in RAS was as follows: NInput (100%) = NHarvest (34.22%) + NShed shells (3.83%) + NDead shrimp (0.69%) + NECR (1.31%) + NMDF (27.67%) + NMBBR (8.75%) + NFS (10.89%) + NWater exchange (9.75%) + NWater accumulation (2.89%).
Moreover, a Chlorella vulgaris culture system was used to recycle the waste nitrogen produced during aquaculture of L. vannamei, and the nitrogen recovery rate was more than 80%. Using microalgae to recover nitrogen from aquaculture tail water not only improves resource utilization and increase income, but also protects the ecological environment.
"We systematically studied the migration and transformation law of N in RAS, and formulated a recovery strategy for waste nitrogen, which is of great significance for the green and healthy development of the aquaculture industry," said XU Jianping, first author of the study.
"The results comprehensively explained the flow characteristics of N element in large-scale recycling aquaculture, and provided a data support for comprehensive understanding of RAS and targeted improvement of water treatment equipment," said Prof. SUN, the corresponding author.
The work was supported by the National Key Research and Development Program of China.
Fig. 1 Schematic diagram of the experimental system
Fig. 2 The budget of input nitrogen (NInput) in the RAS of L. vannamei
Xu, J., Qiu, T., Chen, F., Zhou, L., Du, Y., & Sun, J. (2022). Nitrogen migration law and recycling strategy in an innovative recirculating aquaculture system: Enhancing performance through electrocoagulation. Journal of Water Process Engineering, 50, 103275.
(Text by XU Jianping)
Media Contact:
ZHANG Yiyi
Institute of Oceanology
E-mail: zhangyiyi@qdio.ac.cn
(Editor: ZHANG Yiyi)