Performance of a recirculating aquaculture system using biofloc biofilters with convertible water-treatment efficiencies.
Sci Total Environ
; 754: 141918, 2021 Feb 01.
Article
em En
| MEDLINE
| ID: mdl-32911144
ABSTRACT
To achieve high water-treatment efficiencies and simplify the setup of recirculating aquaculture systems (RAS), this study examined the use of suspended growth reactors (R1 and R2) based on biofloc technology (BFT) as water-treatment biofilters. Moreover, the conversion of the heterotrophic R1 biofilter to a nitrifying role was investigated. During RAS operation using heterotrophic BFT biofilters, R1 and R2 simultaneously controlled total ammonium nitrogen, nitrite (NO2--N), nitrate (NO3--N), soluble reactive phosphate (SRP), and alkalinity, with relevant functional microbes including denitrifying bacteria (DNB), phosphorus accumulating organisms (PAOs), denitrifying PAOs (DNPAOs), glycogen accumulating organisms, ammonia oxidizing bacteria, and nitrite oxidizing bacteria. To achieve low concentrations of nitrogen, phosphorus, and save carbon sources, we were able to quickly convert R1 into a nitrifying BFT biofilter by stopping carbohydrate addition. Although there were dominant relative abundances of DNB, PAOs, and DNPAOs in the converted R1, the lack of carbon sources resulted in continuous rise of NO3--N in the effluent, stable NO2--N removal efficiency, and absence of SRP removal after 40 h. However, R2 retained the previous NO3--N and SRP removal efficiencies with carbohydrate addition. This indicated that this novel RAS using BFT biofilters achieved simultaneous nitrogen and phosphate removal, and that the convertible water-treatment efficiencies of BFT biofilters could be controlled by carbohydrate addition. This approach could simplify the RAS setup and meet real-time water quality demands.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Purificação da Água
/
Nitrificação
Idioma:
En
Ano de publicação:
2021
Tipo de documento:
Article