Abstract Nitrogen (N) and phosphorus (P) budgets in a bioflocs technology (BFT) aquaculture system and a recirculation aquaculture system (RAS) during over-wintering of tilapia (GIFT Oreochromis niloticus)for 64 d were compared in the current study. Fish feed was the major input of N in both systems, specifically, 94±0 % and 82±4 % for the RAS and BFT aquaculture system, respectively. The rate of N recovery in the BFT aquaculture systems was estimated to be 48±5 % of input N, which was significantly different from that of the RAS (37±4 %). There was no significant difference between the RASs and BFT aquaculture systems in terms of P recovery rate. The regular backwashing of the drum filter and biological filter in RAS accounted for 41 ± 2 % of input N and 39 ± 2 % of input P. Approximately 54 % of unassimilated nitrogen N was removed by nitrification in the BFT aquaculture systems. The results from the present study suggest that nitrification may be the dominant pathway for ammonia removal in a BFT aquaculture system rather than by heterotrophic bacterial assimilation.

中文翻译：

---

罗非鱼（GIFT，Oreochromis niloticus）越冬过程中生物絮团养殖系统和循环养殖系统氮磷平衡的比较分析

摘要 本研究比较了罗非鱼（GIFT Oreochromis niloticus）越冬期间生物絮团技术（BFT）水产养殖系统和再循环水产养殖系统（RAS）中的氮（N）和磷（P）预算。鱼饲料是两个系统中氮的主要输入，具体而言，RAS 和 BFT 水产养殖系统分别为 94±0% 和 82±4%。BFT 水产养殖系统中 N 的回收率估计为输入 N 的 48±5%，这与 RAS 显着不同（37±4%）。在磷回收率方面，RAS 和 BFT 水产养殖系统之间没有显着差异。RAS中滚筒过滤器和生物过滤器的定期反冲洗占输入N的41±2%和输入P的39±2%。在 BFT 水产养殖系统中，通过硝化作用去除了大约 54% 的未同化氮。本研究的结果表明，硝化作用可能是 BFT 水产养殖系统中除氨的主要途径，而不是异养细菌同化作用。