Ultra-high nitrogen removal from real municipal wastewater using selective enhancement of glycogen accumulating organisms (GAOs) in a partial nitrification-anammox (PNA) system. (15th February 2023)

• Record Type: Journal Article
• Authors: Wang, Hanbin; Zhang, Liang; Dan, Qiongpeng; Zhang, Yingxin; Wang, Shuying; Zhang, Qiong; Li, Xiyao; Wang, Chuanxin; Peng, Yongzhen
• Is Part Of: Water research. Volume 230(2023)
• Publication Date: 2023-02-15
• Subjects: Endogenous denitrification -- Mainstream anammox -- Phosphorus-accumulating organisms -- Glycogen-accumulating organisms -- Municipal wastewater; Water -- Pollution -- Research -- Periodicals; 363.7394
• DOI: 10.1016/j.watres.2023.119594
• Languages: English
• ISSNs: 0043-1354

Abstract

Highlights: Excellent NRE of 97.5% was achieved with TIN below 2.0mg/L by selective enhanced GAOs. Intermittent phosphorus exclusion with poly-P/VSS below 0.01(w/w) enhanced GAOs. GAOs gained organics outcompeting PAOs at low poly-P and strengthened ED. PNA was unaffected by the enhanced ED and coupled to remove nitrogen in the anoxic stage. EPDA was promoted by the enrichment of GAOs that reduced NO3 − to NO2 − exclusively. Abstract: Integrating endogenous denitrification (ED) into partial nitrification-anammox (PNA) systems by adequately utilizing organics in municipal wastewater is a promising approach to improve nitrogen removal efficiency (NRE). In this study, a novel strategy to inhibit phosphorus-accumulating organisms (PAOs) by inducing phosphorus release and exclusion was adopted intermittently, optimizing organics allocation between PAOs and glycogen-accumulating organisms (GAOs). Enhanced ED-synergized anammox was established to treat real municipal wastewater, achieving an NRE of 97.5±2.2% and effluent total inorganic nitrogen (TIN) of less than 2.0 mg/L. With low poly-phosphorus (poly-P) levels (poly-P/VSS below 0.01 (w/w)), glycogen accumulating metabolism (GAM) acquired organics exceeded that of phosphorus accumulating metabolism (PAM) and dominated endogenous metabolism. Ca. Competibacter (GAO) dominated the community following phosphorus-rich supernatant exclusion, with abundance increasing from 3.4% to 5.7%, accompanied by enhanced ED capacity (0.2 to 1.4 mg N/g VSS /h). The enriched subgroups (GB4, GB5) of Ca. Competibcate r established a consistent nitrate cycle with anammox bacteria (AnAOB) through endogenous partial denitrification (EPD) at a ∆NO2 − -N/∆NH4 + -N of 0.91±0.11, guaranteeing the maintenance of AnAOB abundance and performance. These results provide new insights into the flexibility of PNA for the energy-efficient treatment of low-strength ammonium wastewater. Graphical abstract: Image, graphical abstract