Feasibility and Characteristics of Denitrification Using Excess Sludge as the Sole Carbon Source

Abstract:

Adequate carbon source is critical for biological nutrients removal from wastewater, and waste activated sludge (WAS) treatment or disposal is costly and difficult in wastewater treatment plants. In this study, a novel sludge fermentation process was launched to develop the internal carbon source of WAS to enhance biological nitrogen removal, nitrite and nitrate was directly added into anaerobic fermentation system and then formed WAS anoxic fermentation denitrification system (AFD), in which, the sludge fermentation and denitrification were expected to proceed simultaneously. Experimental results of 40 days’ fermentation showed that 0.12 gNO₂^--N/gVSS and 0.11 gNO₃^--N/gVSS, or 0.26 gNO₂^--N/gVSS-reduction and 0.24 gNO₃^--N/gVSS-reduction, could be simultaneously obtained in AFD, and it could be calculated that 37.9% of total VSS and 80.7% of VSS reduction was utilized for nitrite or nitrate removal, which suggested a good performance of denitrification driven by WAS in AFD. The highest accumulation amount, 204 mg/L, of volatile fatty acids was occurred in the 11th day, which proved a rapid fermentation was present in AFD. Furthermore, the variations of pH or ORP in AFD could well indicate the progress of fermentation and denitrification.

• Periodical: Advanced Materials Research (Volume 487)
• Pages: 69-73
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.487.69
• Online since: March 2012
• Authors: Liang Chang Zhang, Yong Zhen Peng, Yong Bo Li, Shu Ying Wang, Yong Zhi Chen
• Keywords: Caron Source, Denitrification, Nitrate, Nitrite, Waste Activated Sludge

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