Free nitrous acid-based nitrifying sludge treatment in a two-sludge system enhances nutrient removal from low-carbon wastewater. (November 2017)

• Record Type: Journal Article
• Authors: Wang, Dongbo; Fu, Qizi; Xu, Qiuxiang; Liu, Yiwen; Hao Ngo, Huu; Yang, Qi; Zeng, Guangming; Li, Xiaoming; Ni, Bing-Jie
• Is Part Of: Bioresource technology. Volume 244:Part 1(2017)
• Page Start: 920
• Page End: 928
• Publication Date: 2017-11
• Subjects: Nutrient removal -- Low-carbon domestic wastewater -- Free nitrous acid -- Nitrite accumulation -- Denitrifying phosphorus removal; 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.2017.08.045
• Languages: English
• ISSNs: 0960-8524

Abstract

Highlights: A new strategy was developed to enhance nutrient removal from low carbon-wastewater. A FNA-based nitrifying-sludge treatment was used in a two-sludge system. 1.9 mg N/L FNA caused ∼67.8% of nitrite accumulation in the nitrifying reactor. 1.9 mg N/L FNA caused ∼83% in nitrogen removal and ∼88% in phosphate removal. FNA treatment reduced the abundance of nitrite oxidizing bacteria. Abstract: A new method to enhance nutrient removal from low carbon-wastewater was developed. The method consists of a two-sludge system (i.e., an anaerobic-anoxic-oxic reactor coupled to a nitrifying reactor (N-SBR)) and a nitrifying-sludge treatment unit using free nitrous acid (FNA). Initially, 65.1 ± 2.9% in total nitrogen removal and 69.6 ± 3.4% in phosphate removal were obtained without nitrite accumulation. When 1/16 of the nitrifying sludge was daily treated with FNA at 1.1 mg N/L for 24 h, ∼28.5% of nitrite was accumulated in the N-SBR, and total nitrogen and phosphate removal increased to 72.4 ± 3.2% and 76.7 ± 2.9%, respectively. About 67.8% of nitrite was accumulated at 1.9 mg N/L FNA, resulting in 82.9 ± 3.8% in total nitrogen removal and 87.9 ± 3.5% in phosphate removal. Fluorescence in-situ hybridization analysis showed that FNA treatment reduced the abundance of nitrite oxidizing bacteria (NOB), especially that of Nitrospira sp.