Search

This research investigated two proposed modified biofilm carriers' performances in treating recirculating aquaculture systems (RAS) wastewater under different salinities (12‰, 26‰, and 35‰) for about 92 days. Three moving bed biofilm reactors (MBBRs; R1, R2, and R3) were filled with unmodified novel sponge biocarriers (SB) served as a control, modified novel SB with ferrous oxalate (C 2 FeO 4 @SB), and modified novel SB with combined ferrous oxalate and activated carbon (C 2 FeO 4 -AC@SB), respectively. Under the highest saline condition, a significantly higher ammonia removal efficiency of 98.86 ± 0.7% (p ˃ 0.05) was obtained in R3, whereas R2 and R1 yielded 95.18 ± 2.8% and 91.66 ± 1.5%, respectively. Microbial analysis showed that Vibrio, Ruegeria , Formosa, Thalassospira, and Denitromonas were predominant genera, strictly halophilic heterotrophic nitrifying bacteria involved in nitrogen removal. In conclusion, the synergistic effects of novel sponge, C 2 FeO 4 and AC accelerated biofilm formations and stability, subsequently enhanced the removal of ammonia from the mariculture RAS wastewater by the C 2 FeO 4 -AC@SB carriers in R3. • Modified sponge biocarriers (C 2 FeO 4 @SB) and C 2 FeO 4 -AC@SB were prepared. • The first study to evaluate C 2 FeO 4 @SB and C 2 FeO 4 -AC@SB as biofilm carriers in MBBR. • C 2 FeO 4 -AC@SB bioreactor recorded over 98.86% ammonia removal. • The present study also elucidated the impact of salinity on the microbial community. [ABSTRACT FROM AUTHOR]