Ionic liquid coupled plasma promotes acetic acid production during anaerobic fermentation of waste activated sludge: Breaking the restrictions of low bioavailable substrates and altering the metabolic activities of anaerobes.
Water Res
; 261: 122048, 2024 Sep 01.
Article
en En
| MEDLINE
| ID: mdl-38981353
ABSTRACT
This study explored the potential application of plasma coupling ionic liquid on disintegration of waste activated sludge and enhanced production of short-chain fatty acids (SCFAs) in anaerobic fermentation. Under optimal conditions (dosage of ionic liquid [Emim]OTf = 0.1 g/g VSS (volatile suspended solids) and discharge power of dielectric barrier discharge plasma (DBD) = 75.2 W), the [Emim]OTf/DBD pretreatment increased SCFA production by 302 % and acetic acid ratio by 53 % compared to the control. Mechanistic investigations revealed that the [Emim]OTf/DBD combination motivated the generation of various reactive species (such as H2O2, O3, â¢OH, 1O2, ONOO-, and â¢O2-) and enhanced the utilization of physical energies (such as heat). The coupling effects of [Emim]OTf/DBD synergistically improved the disintegration of sludge and biodegradability of dissolved organic matter, promoting the sludge anaerobic fermentation process. Moreover, the [Emim]OTf/DBD pretreatment enriched hydrolysis and SCFAs-forming bacteria while inhibiting SCFAs-consuming bacteria. The net effect was pronounced expression of genes encoding key enzymes (such as alpha-glucosidase, endoglucanase, beta-glucosidase, l-lactate/D-lactate dehydrogenase, and butyrate kinase) involved in the SCFA-producing pathway, enhancing the production of SCFAs from sludge anaerobic fermentation. In addition, [Emim]OTf/DBD pretreatment facilitated sludge dewatering and heavy metal removal. Therefore, [Emim]OTf/DBD pretreatment is a promising approach to advancing sludge reduction, recyclability, and valuable resource recovery.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Aguas del Alcantarillado
/
Ácido Acético
/
Líquidos Iónicos
/
Fermentación
Idioma:
En
Revista:
Water Res
Año:
2024
Tipo del documento:
Article
País de afiliación:
China