Sludge decay kinetics and metagenomic analysis uncover discrepant metabolic mechanisms in two different sludge in situ reduction systems.
Sci Total Environ
; 851(Pt 2): 158346, 2022 Dec 10.
Article
em En
| MEDLINE
| ID: mdl-36041603
ABSTRACT
A comparative study was conducted between an anaerobic side-stream reactor (ASSR) process and a sludge process reduction (SPR) activated sludge (SPRAS) process for uncovering crucial metabolic mechanisms governing sludge reduction. Both of two processes were efficient in removing pollutants, while the SPRAS (62.3 %) obtained much higher sludge reduction than the ASSR (27.9 %). The highest rate coefficients of sludge decay, heterotroph lysis and particles hydrolysis were 0.106, 0.219 and 0.054 d-1 in the SPR module, followed by ASSR with coefficients of 0.060, 0.135 and 0.047 d-1. The SPR module achieved an 81.9 % higher sludge decay mass with a 32.8 % smaller volume than the ASSR module. The SPR module preferentially enriched hydrolytic/fermentative and slow-growing bacteria. Metagenomic analysis revealed that SPR strengthened the key hydrolases and L-lactate dehydrogenase in the glycolysis pathways and weakened the citrate cycle, inducing metabolic uncoupling due to the reduced biosynthesis of ATP. Inserting ASSR only altered the ATP biosynthesis pathway, but maintenance metabolism was dominant for sludge reduction, with a long sludge retention time prolonging the food chain for predation.
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Texto completo:
1
Coleções:
01-internacional
Contexto em Saúde:
2_ODS3
Base de dados:
MEDLINE
Assunto principal:
Esgotos
/
Poluentes Ambientais
Idioma:
En
Revista:
Sci Total Environ
Ano de publicação:
2022
Tipo de documento:
Article