title: Free nitrous acid pretreatment of wasted activated sludge to exploit internal carbon source for enhanced denitrification.
abstract: Using internal carbon source contained in waste activated sludge (WAS) is beneficial for nitrogen removal from wastewater with low carbon/nitrogen ratio, but it is usually limited by sludge disintegration. This study presented a novel strategy based on free nitrous acid (FNA) pretreatment to intensify the release of organic matters from WAS for enhanced denitrification. During FNA pretreatment, soluble chemical oxygen demand (SCOD) production kept increasing when FNA increased from 0 to 2.04 mg HNO2-N/L. Compared with untreated WAS, the internal carbon source production increased by 50% in a simultaneous fermentation and denitrification reactor fed with WAS pretreated by FNA for 24 h at 2.04 mg HNO2-N/L. This also increased denitrification efficiency by 76% and sludge reduction by 87.5%. More importantly, greenhouse gas nitrous oxide production in denitrification was alleviated since more electrons could be provided by FNA pretreated WAS.
authors.affiliation: Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China.
authors.forename: Bin
authors.initials: B
authors.lastname: Ma
authors.affiliation: Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China. Electronic address: pyz@bjut.edu.cn.
authors.forename: Yongzhen
authors.initials: Y
authors.lastname: Peng
authors.affiliation: Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Wei
authors.affiliation: Department of Civil and Environmental Engineering, University of Connecticut, Storrs, CT 06269, USA.
authors.forename: Baikun
authors.initials: B
authors.lastname: Li
authors.affiliation: Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China.
authors.forename: Peng
authors.initials: P
authors.lastname: Bao
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Siping Road, Shanghai 200092, PR China.
authors.forename: Yayi
authors.initials: Y
authors.lastname: Wang
mesh_terms: D057919:Biological Oxygen Demand Analysis; D001709:Biotechnology / Q000379:methods*; D002244:Carbon / Q000737:chemistry*; D058440:Denitrification; D005232:Fatty Acids, Volatile / Q000032:analysis; D005285:Fermentation; D009608:Nitrous Acid / Q000737:chemistry*; D009930:Organic Chemicals / Q000032:analysis; D011134:Polysaccharides / Q000032:analysis; D011506:Proteins / Q000032:analysis; D012722:Sewage / Q000737:chemistry*; D018508:Water Purification
chemical_list: D005232:Fatty Acids, Volatile; D009930:Organic Chemicals; D011134:Polysaccharides; D011506:Proteins; D012722:Sewage; D002244:Carbon; D009608:Nitrous Acid
keywords: Denitrification; Fermentation; Free nitrous acid; Pretreatment; Waste activated sludge