Modified integrated fixed-film activated sludge process: Advanced nitrogen removal for low-C/N domestic wastewater. (November 2022)

• Record Type: Journal Article
• Authors: Liang, Zixuan; Han, Hongbo; Yi, Jing; Dai, Xiaohu
• Is Part Of: Chemosphere. Volume 307:Part 2(2022)
• Publication Date: 2022-11
• Subjects: Nitrogen removal -- Powder carrier -- Fe–C -- Diatomite -- Hydrocyclone separator; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2022.135827
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Actual low-C/N domestic wastewater was treated using the high-concentration powder carrier bio-fluidized bed (HPB) process comparing diatomite and Fe–C as the carriers. The total nitrogen removal efficiencies were increased from 50.08% to 65.40% and 78.58%, respectively. The diatomite HPB process increased the relative abundance of autotrophic N-cycle bacteria to more than twofold and the sludge size. Therefore, the contributions for nitrogen removal by anammox and simultaneous nitrification–denitrification were increased. The Fe–C HPB process improved the nitrogen removal efficiency mainly by increasing the biodegradability and activities of electron transfer system and key enzymes. The key device (hydrocyclone separator) of the HPB process significantly improved the recovery efficiency of the carriers. It also improved the capacity of microbial aggregations for adsorbing pollutants. Furthermore, it reduced the relative abundance of filamentous bacteria. This study demonstrated the feasibility and mechanism of the HPB process for improving the nitrogen removal efficiency for low-C/N wastewater. Graphical abstract: Image 1 Highlights: The TNRE was increased from 50.08% to 78.58% by the Fe–C HPB process. The recovery efficiency of carrier achieved to 70% after 90 d operation. The abundance of autotrophic N-cycle bacteria was increased to more than twofold. The contributions of anammox pathway in the Fe–C HPB processed was as high as 13.61%.