title: Role of nitrification in the biodegradation of selected artificial sweetening agents in biological wastewater treatment process.
abstract: The biodegradation of the six artificial sweetening agents including acesulfame (ACE), aspartame (ASP), cyclamate (CYC), neohesperidindihydrochalcone (NHDC), saccharin (SAC), and sucralose (SUC) by nitrifying activated sludge was first examined. Experimental results showed that ASP and NHDC were the most easily degradable compounds even in the control tests. CYC and SAC were efficiently biodegraded by the nitrifying activated sludge, whereas ACE and SUC were poorly removed. However, the biodegradation efficiencies of the ASs were increased with the increase in initial ammonium concentrations in the bioreactors. The association between nitrification and co-metabolic degradation was investigated and a linear relationship between nitrification rate and co-metabolic biodegradation rate was observed for the target artificial sweeteners (ASs). The contribution of heterotrophic microorganisms and autotrophic ammonia oxidizers in biodegradation of the ASs was elucidated, of which autotrophic ammonia oxidizers played an important role in the biodegradation of the ASs, particularly with regards to ACE and SUC.
authors.affiliation: Department of Civil and Environmental Engineering, Faculty of Engineering, National University of Singapore, 1 Engineering Drive 2, Singapore 117576, Singapore. Electronic address: ceetnh@nus.edu.sg.
authors.forename: N H
authors.initials: NH
authors.lastname: Tran
authors.affiliation: Department of Civil and Environmental Engineering, Faculty of Engineering, National University of Singapore, 1 Engineering Drive 2, Singapore 117576, Singapore.
authors.forename: V T
authors.initials: VT
authors.lastname: Nguyen
authors.affiliation: School of Bioscience and Biotechnology, Tokyo University of Technology, Katakura 1404-1, Hachioji, Tokyo 192-0982, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Urase
authors.affiliation: School of Civil and Environmental Engineering, University of Technology Sydney, PO Box 123, Broadway, NSW 2007, Australia.
authors.forename: H H
authors.initials: HH
authors.lastname: Ngo
mesh_terms: D064751:Ammonium Compounds / Q000378:metabolism; D001673:Biodegradation, Environmental; D058465:Nitrification; D013549:Sweetening Agents / Q000737:chemistry / Q000378:metabolism*; D018508:Water Purification
chemical_list: D064751:Ammonium Compounds; D013549:Sweetening Agents
keywords: Ammonia monooxygenase; Artificial sweeteners; Autotrophic ammonia oxidizers; Co-metabolism; Nitrification