Long-term impacts of carboxyl functionalized multi-walled carbon nanotubes on the performance, microbial enzymatic activity and microbial community of sequencing batch reactor. (August 2019)

• Record Type: Journal Article
• Authors: Ma, Bingrui; Gao, Feng; Yu, Naling; Zhao, Changkun; Li, Shanshan; She, Zonglian; Guo, Liang; Jin, Chunji; Zhao, Yangguo; Gao, Mengchun
• Is Part Of: Bioresource technology. Volume 286(2019)
• Publication Date: 2019-08
• Subjects: MWCNTs-COOH -- Activated sludge -- Reactive oxygen species -- Lactate dehydrogenase -- Nitrifying and denitrifying bacteria; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2019.121382
• Languages: English
• ISSNs: 0960-8524

Abstract

Highlights: Long-term exposure of MWCNTs-COOH affected the COD and nitrogen removal of SBR. MWCNTs-COOH inhibited the microbial enzymatic activity and nitrogen removal rate. MWCNTs-COOH stimulated more ROS production and LDH release from activated sludge. MWCNTs-COOH declined microbial richness and diversity of activated sludge. Abstract: The performance, microbial community and enzymatic activity of sequencing batch reactors (SBRs) were evaluated under long-term exposure of 0, 10 and 30 mg/L carboxyl functionalized multi-walled carbon nanotubes (MWCNTs-COOH). The presence of 10 mg/L MWCNTs-COOH displayed no adverse impacts on the COD and NH4 + -N removal of SBR, whereas 30 mg/L MWCNTs-COOH declined the COD and NH4 + -N removal. MWCNTs-COOH inhibited the denitrifying process and led to the accumulation of effluent NO2 − -N concentration. The inhibition of MWCNTs-COOH on the oxygen utilization rate, nitrogen removal rate and enzymatic activity of activated sludge gradually enhanced with the increase of operating time and influent MWCNTs-COOH concentration. MWCNTs-COOH stimulated more reactive oxygen species production and lactate dehydrogenase release, which might affect the microbial physiological functions and morphology. The microbial diversity and richness was declined evidently after long-term exposure of MWCNTs-COOH. The relative abundance of nitrifying and denitrifying bacteria showed some changes under MWCNTs-COOH stress.