Intermittent Oxygen Supply Facilitates Codegradation of Trichloroethene and Toluene by Anaerobic Consortia.
Environ Sci Technol
; 57(28): 10252-10262, 2023 07 18.
Article
em En
| MEDLINE
| ID: mdl-37422855
ABSTRACT
Biodegradation is commonly employed for remediating trichloroethene- or toluene-contaminated sites. However, remediation methods using either anaerobic or aerobic degradation are inefficient for dual pollutants. We developed an anaerobic sequencing batch reactor system with intermittent oxygen supply for the codegradation of trichloroethylene and toluene. Our results showed that oxygen inhibited anaerobic dechlorination of trichloroethene, but dechlorination rates remained comparable to that at dissolved oxygen levels of 0.2 mg/L. Intermittent oxygenation engendered reactor redox fluctuations (-146 to -475 mV) and facilitated rapid codegradation of targeting dual pollutants, with trichloroethene degradation constituting only 27.5% of the noninhibited dechlorination. Amplicon sequencing analysis revealed the predominance of Dehalogenimonas (16.0% ± 3.5%) over Dehalococcoides (0.3% ± 0.2%), with ten times higher transcriptomic activity in Dehalogenimonas. Shotgun metagenomics revealed numerous genes related to reductive dehalogenases and oxidative stress resistance in Dehalogenimonas and Dehalococcoides, as well as the enrichment of diversified facultative populations with functional genes related to trichloroethylene cometabolism and aerobic and anaerobic toluene degradation. These findings suggested that the codegradation of trichloroethylene and toluene may involve multiple biodegradation mechanisms. Overall results of this study demonstrate the effectiveness of intermittent micro-oxygenation in aiding trichloroethene-toluene degradation, suggesting the potential for the bioremediation of sites with similar organic pollutants.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Contexto em Saúde:
2_ODS3
Problema de saúde:
2_quimicos_contaminacion
Assunto principal:
Tricloroetileno
/
Chloroflexi
/
Poluentes Ambientais
Idioma:
En
Revista:
Environ Sci Technol
Ano de publicação:
2023
Tipo de documento:
Article
País de afiliação:
Taiwan