Abstract Sewage collection and dissolved oxygen (DO) management have always been the focus of industrialized recirculating aquaculture. However, there are still no reports on how to achieve efficient sewage collection and increase DO in rectangular water tanks. In the present study, the performance of sewage collection and aeration in rectangular water tanks were compared among three fine-pore aeration tubes (disc-type diffuser, four corner-type diffuser and distribute-type diffuser) layouts at three airflow rates, 6, 18, and 30 m3/h. The results of computational fluid dynamics (CFD) modeling and bait collection tests revealed that sewage collection using the four corner-type diffuser was better than using the disc-type diffuser and the distribute-type diffuser. Using the four corner-type diffuser, a strip-shaped sewage collector could be set up at the bottom of the tank to collect sewage at an airflow rate of 18 m3/h and a disc-shaped sewage collector could be set up at the bottom of the tank to collect sewage at an air flow rate of 30 m3/h. In terms of aeration, volumetric oxygen transfer coefficient (KLa20), standard oxygen transfer rate (SOTR), and standard oxygen transfer efficiency (SOTE) of the distribute-type diffuser were all the highest at the three airflow rates, followed by four corner-type diffuser, and finally the disc-type diffuser, indicating that the aeration performance in the distribute-type diffuser was optimal. However, there were no significant differences in KLa20, SOTR, and SOTE between the four corner-type diffuser and the distribute-type diffuser at both 18 and 30 m3/h airflow rates. Therefore, four corner-type diffusers were the optimal choice for recirculating aquaculture, considering the sewage collection and aeration requirements. The results of the present offer novel insights on the application of CFD in recirculating aquaculture, in addition to basic data and theoretical guidance on how to achieve efficient sewage collection and aeration in recirculating aquaculture.

中文翻译：

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细孔曝气管不同布置方式对矩形水箱污水收集曝气的影响

摘要 污水收集和溶解氧（DO）管理一直是工业化循环水养殖的重点。然而，关于如何在矩形水箱中实现高效的污水收集和增加溶解氧，目前还没有报道。在本研究中，比较了三种细孔曝气管（盘式散流器、四角式散流器和分布式散流器）在三种气流速率下的矩形水箱中污水收集和曝气的性能，6， 18 和 30 立方米/小时。计算流体动力学 (CFD) 建模和诱饵收集测试的结果表明，使用四角式扩散器的污水收集效果优于使用圆盘式扩散器和分布式扩散器。使用四角型扩散器，池底可设置条形集水器，收集风量为18 m3/h的污水，池底可设置圆盘形集水器，收集污水。空气流速为 30 立方米/小时。在曝气方面，分布型扩散器的体积氧传递系数（KLa20）、标准氧传递率（SOTR）和标准氧传递效率（SOTE）在三种气流速率下均最高，其次是四个角-型扩散器，最后是圆盘型扩散器，表明分布型扩散器的曝气性能最佳。然而，在 18 和 30 m3/h 的气流速率下，四角型扩散器和分布型扩散器之间的 KLa20、SOTR 和 SOTE 没有显着差异。所以，考虑到污水收集和曝气要求，四个角型扩散器是循环水养殖的最佳选择。除了关于如何在循环水养殖中实现高效污水收集和曝气的基础数据和理论指导之外，本文的结果还为 CFD 在循环水养殖中的应用提供了新的见解。