Enhanced nitrogen removal from sludge dewatering liquor by simultaneous primary sludge fermentation and nitrate reduction in batch and continuous reactors

• Published in: Bioresource technology Vol. 104; pp. 144 - 149
• Main Authors: Peng, Yongzhen, Zhang, Liang, Zhang, Shujun, Gan, Yiping, Wu, Chengcheng
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.01.2012
• Subjects: Batch Cell Culture Techniques - instrumentation; Bioreactors - microbiology; Denitrification; Denitrification - physiology; Dewatering; Effluents; Equipment Design; Equipment Failure Analysis; Fermentation; Fermentation - physiology; Nitrates; Nitrates - isolation & purification; Nitrates - metabolism; Nitrogen - isolation & purification; Nitrogen - metabolism; Nitrogen removal; Oxidation-Reduction; Primary sludge; Reactors; Reduction; Sewage - microbiology; Sludge; Sludge dewatering liquors; Sludge fermentation; Water - chemistry; Water Microbiology; Denitrification; Nitrogen removal; Primary sludge; Sludge fermentation; Sludge dewatering liquors
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2011.10.079

► We use primary sludge as the carbon source to enhance nitrogen removal of reject water in a novel system. ► Good nitrogen removal could be accomplished with the co-occurrence of sludge fermentation and denitrification. ► The degradation of primary sludge was accelerated by the existence of nitrate. ► The decrease of ammonia is observed in sludge fermentation process when nitrate is added. ► Integration of fermentation and denitrification are more attractive than conventional fermentation–elutriation. In this study, a novel denitrification reactor is used to treat sludge dewatering liquor, where the co-occurrence of sludge fermentation and nitrate reduction was obtained. The system showed an efficient and stable nitrogen removal performance. When the effluent recycle ratio was 200%, TN and NH4+ removal efficiency was 99.6% and 83.5%, respectively. In addition, primary sludge could be well degraded in the novel system. Over 50% volatile suspended solid (VSS) of primary sludge was utilized, and the ratio of VSS/SS declined from 0.76 to 0.39. Further investigation with batch experiments revealed that, compared to conventional sludge fermentation, the integration of denitrification and fermentation was better at carbon production as well as the control of ammonium release.