Nitrogen removal of anaerobically digested swine wastewater by pilot-scale tidal flow constructed wetland based on in-situ biological regeneration of zeolite.
Chemosphere
; 217: 364-373, 2019 Feb.
Article
em En
| MEDLINE
| ID: mdl-30419390
Dispersed swine wastewater has increasingly aggravated water pollution in China. Anaerobically digested dispersed swine wastewater was targeted and treated by a pilot-scale zoning tidal flow constructed wetland (TFCW) with a bottom wastewater saturation layer. The long-term application of in-situ biological regeneration of biozeolite, nitrogen removal performance, nitrogen removal pathways and microbial community of TFCW were investigated. Results showed that with the surface loads of 0.079, 0.022 and 0.024â¯kg/(m2·d), TFCW could decrease COD, NH4N and TN by 84.75%, 74.13% and 67.13% respectively. Influent COD, NH4N, TN and nitrates/nitrites produced by bioregeneration of NH4N were mostly removed in zeolite layer and the remaining nitrates/nitrites could be further denitrified in bottom saturation layer. Theory of dynamic process of rapid-adsorption and bioregeneration for NH4N removal was proposed. When this process reached dynamic equilibrium, the mass of adsorbed NH4N onto zeolites remained relatively stable. When ambient temperature decreased to 16⯰C, TFCW could still remove COD, NH4N and TN by 73.79%, 72.99% and 70.71% with the surface loads of 0.103, 0.056 and 0.054â¯kg/(m2·d) respectively. Nitrification-denitrification which accounted for 80.32% of TN removal was the main nitrogen removal pathway. Dominant nitrifiers (Nitrosospira and Rhizomicrobium) and denitrifiers (Ottowia, Thauera and Rhodanobacteria) in biozeolite layer verified the existence of simultaneous nitrification and denitrification.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Zeolitas
/
Áreas Alagadas
/
Águas Residuárias
/
Nitrogênio
Limite:
Animals
País/Região como assunto:
Asia
Idioma:
En
Revista:
Chemosphere
Ano de publicação:
2019
Tipo de documento:
Article