Effect of florfenicol on performance and microbial community of a sequencing batch biofilm reactor treating mariculture wastewater

ABSTRACT

The effects of florfenicol (FF) on the performance, microbial activity and microbial community of a sequencing batch biofilm reactor (SBBR) were evaluated in treating mariculture wastewater. The chemical oxygen demand (COD) and nitrogen removal were inhibited at high FF concentrations. The specific oxygen utilization rate (SOUR), specific ammonium oxidation rate (SAOR), specific nitrite oxidation rate (SNOR) and specific nitrate reduction rate (SNRR) were decreased with an increase in the FF concentration from 0 to 35 mg/L. The chemical compositions of loosely bound extracellular polymeric substances (LB-EPS) and tightly bound EPS (TB-EPS) could be affected with an increase in the FF concentration. The high-throughput sequencing indicated some obvious variations in the microbial community at different FF concentrations. The relative abundance of Nitrosomonas and Nitrospira showed a decreasing tendency with an increase in the FF concentration, suggesting that FF could affect the nitrification process of SBBR. Some genera capable of reducing nitrate to nitrogen gas could be inhibited by the addition of FF in the influent, such as Azospirillum and Hyphomicrobium.

KEYWORDS:

• Florfenicol
• microbial activity
• SBBR
• extracellular polymeric substances
• microbial community

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Feng Gao http://orcid.org/0000-0003-2566-4850

Zhiwei Li http://orcid.org/0000-0002-6037-3269

Juan Wu http://orcid.org/0000-0002-9165-8224

Additional information

Funding

The work was funded by the National Natural Science Foundation of China [grant number 51178437].