Characteristics of Tetracycline Degradation Coupled Simultaneous Nitrification-Denitrification and Phosphorus Removal in Aquaculture Wastewater

Abstract

Although residual tetracycline, NH₄⁺-N, and P in aquaculture wastewater have been frequently detected, their simultaneous removal has received little attention. The simultaneous and efficient removal of tetracycline, NH₄⁺-N, COD, and P in aquaculture wastewater was achieved with a laboratory-scale moving bed biofilm reactor (MBBR) under different influent C/N ratios. The results suggested that tetracycline could be degraded efficiently without using an additional organic carbon source. Most of the tetracycline (>80%), NH₄⁺-N (>73%), TN (>68%), TP (>59%), and COD (>78%) were synchronously removed under the higher C/N ratios. The electron transport system activity (ETSA), dissolved organic matter (DOM), and extracellular polymeric substances (EPS) were evaluated for biofilm performance during aquaculture wastewater remediation. The results indicated that the protein (PN) and polysaccharide (PS) concentrations, and fluorescence intensities were significantly different because the influent C/N ratios changed the biofilm activity. The ETSA values were lowest when tetracycline was the sole carbon source, which suggested that tetracycline affected the nitrification activity of biofilms. Sphingobacteriia, Betaproteobacteria, and Alphaproteobacteria were identified as the dominant bacterial classes. This study provides a new strategy for the removal of tetracycline and nutrients from aquaculture wastewater.

Keywords:

• Moving bed biofilm reactor (MBBR)
• biofilm activity
• microbial community
• aquaculture wastewater

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The research was financially supported by the Key Projects of Natural Science Research in Colleges and Universities of Anhui Province (No. KJ2020A0128), Natural Science Youth Fund Project of Anhui Agricultural University (No. 2020zd13), and Research Support Project for Stabilizing and Introducing Talents of Anhui Agricultural University (No. rc522010).