In-situ ammonia stripping with alkaline fermentation of waste activated sludge to improve short-chain fatty acids production and carbon source availability

• Published in: Bioresource technology Vol. 301; p. 122782
• Main Authors: Ye, Min, Luo, Jinghuan, Zhang, Sitong, Yang, Huan, Li, Yu-You, Liu, Jianyong
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.04.2020
• Subjects: activated sludge; Alkaline fermentation; Ammonia; ammonium nitrogen; Carbon; Carbon source; chemical oxygen demand; denitrification; Fatty Acids, Volatile; Fermentation; Hydrogen-Ion Concentration; In-situ ammonia stripping; municipal wastewater; Sewage; Short-chain fatty acids; total suspended solids; Waste activated sludge; wastewater treatment; Short-chain fatty acids; Alkaline fermentation; Waste activated sludge; Carbon source; In-situ ammonia stripping
• ISSN: 0960-8524; 1873-2976; 1873-2976
• DOI: 10.1016/j.biortech.2020.122782

[Display omitted] •In-situ ammonia stripping improved SCFAs production from WAS alkaline fermentation.•21.7% of SCFAs increase with WAS hydrolysis enhanced and free from FA inhibition.•Most NH4+-N was stripped out with residue NH4+ of ~20 mg N/L in supernatant.•SCFAs availability as carbon source increased by 103.2% by ammonia stripping. Alkaline fermentation of waste activated sludge (WAS) to produce short-chain fatty acids (SCFAs) has been proved to be promising to develop internal carbon source for denitrifying processes in municipal wastewater treatment plants. However, a large amount of ammoniacal nitrogen also releases during fermentation, resulting in inhibition of acidogenic process and reduction of carbon source availability. Alkaline fermentation of WAS combined with in-situ ammonia stripping was proposed to improve SCFAs production and carbon source availability simultaneously. The results showed that a maximal SCFAs production of 308.7 ± 4.8 mg chemical oxygen demand/g volatile suspended solid was achieved under the pH = 10 + In-situ ammonia stripping, which was 21.7% and 141.5% higher than that of the pH = 10 and the control, respectively. Most of the ammoniacal nitrogen was stripped out, and the WAS-derived SCFAs availability as carbon source increased by 103.2%. These findings indicate in-situ ammonia stripping could make alkaline fermentation of WAS more practical.