Comparative analysis of nitrogen and phosphorus budgets in a bioflocs aquaculture system and recirculation aquaculture system during over-wintering of tilapia (GIFT, Oreochromis niloticus)

• Published in: Aquacultural engineering Vol. 89; p. 102026
• Main Authors: Cao, Baoxin, Abakari, Godwin, Luo, Guozhi, Tan, Hongxin, Xia, Wu
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.05.2020
• Subjects: Bioflocs; Nitrogen budget; Over-Winter; Phosphorus budget; Recirculating aquaculture system; Technology; Tilapia; Over-Winter; Bioflocs; Technology; Phosphorus budget; Tilapia; Recirculating aquaculture system; Nitrogen budget
• ISSN: 0144-8609; 1873-5614
• DOI: 10.1016/j.aquaeng.2019.102026

•The recovery rate of N in BFTSs (48 ± 5 %) was significantly higher than that of RASs (37 ± 4 %).•No significant difference between the RASs and BFTSs in terms of P recovery rate.•Regular backwashing in RAS accounted for 41 ± 2 % of input N and 39 ± 2 % input P.•Nitrification was the dominant TAN pathway in a BFTS rather than heterotrophic assimilation. 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.