Low carbon-to-nitrogen ratio digestate from high-rate anaerobic baffled reactor facilitates heterotrophic/autotrophic nitrifiers involved in nitrogen removal. (September 2022)

• Record Type: Journal Article
• Authors: Zhou, Xiangtong; Arslan, Muhammad; Liu, Zhigang; Li, Da; Xi, Haipeng; Feng, Yujie; Li, Shanwei; Wei, Jing; Rong, Xinshan; Liang, Zhishui; Wang, Xiaochun; Wu, Zhiren; Gamal El-Din, Mohamed
• Is Part Of: Bioresource technology. Volume 359(2022)
• Publication Date: 2022-09
• Subjects: Domestic wastewater -- Biomass entrapment -- Baffled anaerobic–aerobic reactor -- Bio-nest -- Metagenomics -- Nitrogen metabolic pathway; 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.2022.127346
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: Baffled anaerobic–aerobic bioreactors were used to treat low-strength DWW. More functional microorganisms were entrapped by introducing MBF carriers. HN-AD species growth was facilitated by influx of low C/N ratio digestate. Nitrogen metabolic pathways were interpreted based on metagenomics. Abstract: In this study, baffled anaerobic–aerobic reactors (AOBRs) with modified basalt fiber (MBF) carriers and felt were used to treat domestic wastewater (DWW). The influent was first treated in anaerobic compartments, with the NH4 + -N containing digestate refluxed into aerobic compartment for nitrification. The nitrified liquid was channeled to the anaerobic compartments for further denitrification. Under optimal conditions, AOBR with MBF carriers could remove 91% chemical oxygen demand (COD) and 81% total nitrogen (TN), with biomass production increased by 7.6%, 4.5% and 8.7% in three successive anaerobic compartments compared to the control. Biological viability analysis showed that live cells outnumbered dead cells in bio-nests. Metagenomics analysis showed that multiple metabolic pathways accounted for nitrogen conversion in anaerobic and aerobic compartments. More importantly, low COD/TN ratio digestate facilitated heterotrophic nitrification-aerobic denitrification (HN-AD) species growth in aerobic compartment. This study provides a promising strategy to source treatment of DWW from urban communities.