Enhancement of nitrite/ammonia removal from saline recirculating aquaculture wastewater system using moving bed bioreactor. Issue 5 (October 2021)

• Record Type: Journal Article
• Authors: Tadda, Musa Abubakar; Li, Changwei; Gouda, Mostafa; Abomohra, Abd El-Fatah; Shitu, Abubakar; Ahsan, Amimul; Zhu, Songming; Liu, Dezhao
• Is Part Of: Journal of environmental chemical engineering. Volume 9:Issue 5(2021)
• Publication Date: 2021-10
• Subjects: Recirculating aquaculture system (RAS) -- Moving bed biofilm reactor (MBBR) -- Mature biofilms -- Nitrite removal -- Aerobic denitrifiers -- Partial least squares-discriminant analysis (PLS-DA); Chemical engineering -- Environmental aspects -- Periodicals; Environmental engineering -- Periodicals; Chemical engineering -- Environmental aspects; Environmental engineering; Periodicals; 660.0286
• DOI: 10.1016/j.jece.2021.105947
• Languages: English
• ISSNs: 2213-2929

Abstract

Abstract: Innovative removal of toxic nitrite and ammonia is one of the key approaches for efficient aquaculture biotechnology. This study suggests a fast removal technique of high-levels of nitrite and ammonia using recirculating aquaculture wastewater at 30‰ salinity. Four lab-scale moving bed biofilm reactors (MBBRs; R1, R2, R3, and R4) were operated in parallel for 56 days with different combinations of mature and fresh biofilms on biocarriers at 30% filling ratio. Nitrogen removal efficiency, biofilm physicochemical properties, and microbial analyses were conducted using PCR and sequencing techniques at the region of the 16S ribosomal RNA. The results showed that R4 (using mature biofilms) recorded the highest nitrite and ammonia removal (99.6% and 95.3%, respectively) compared to the control, R1 (94.1% and 89.4%). Meanwhile, the removal rate of ammonia in R4 was significantly the fastest compared to other reactors. Partial Least Squares-Discriminant Multivariate Analysis (PLS-DA) model showed a good prediction with very high accuracy and prediction (Q2 > 0.8) for the first three principal components pertaining to nitrite and ammonia removal. Planktosalinus genus was the most abundant in R4, while proteobacteria phylum was the dominant, followed by Marinobacter and Nitrospina in all reactors. Overall, the use of mature biofilms in MBBR was proven to increase bacterial diversity, enhancing nitrite and ammonia removal efficiency. Graphical Abstract: ga1 Highlights: Lab-scale moving bed biofilm reactors (MBBRs) were used in the present study. Mature biofilms MBBR showed the highest nitrite and ammonia removal efficiency. MBBR with mature biofilm increased nitrate concentration to 51.7 mg L −1 after 2 days. Planktosalinus was the dominant genus in all MBBRs, with least number in the control. New biofilms MBBR showed the highest population of Bacteroidetes (45.92%).