title: Occurrence of trace organic contaminants in wastewater sludge and their removals by anaerobic digestion.
abstract: This study aims to evaluate the occurrence of trace organic contaminants (TrOCs) in wastewater sludge and their removal during anaerobic digestion. The significant occurrence of 18 TrOCs in primary sludge was observed. These TrOCs occurred predominantly in the solid phase. Some of these TrOCs (e.g. paracetamol, caffeine, ibuprofen and triclosan) were also found at high concentrations (>10,000ng/L) in the aqueous phase. The overall removal of TrOCs (from both the aqueous and solid phase) by anaerobic digestion was governed by their molecular structure (e.g. the presence/absence of electron withdrawing/donating functional groups). While an increase in sludge retention time (SRT) of the digester resulted in a small but clearly discernible increase in basic biological performance (e.g. volatile solids removal and biogas production), the impact of SRT on TrOC removal was negligible. The lack of SRT influence on TrOC removal suggests that TrOCs were not the main substrate for anaerobic digestion.
authors.affiliation: Strategic Water Infrastructure Lab, School of Civil, Mining and Environmental Engineering, University of Wollongong, NSW 2522, Australia.
authors.forename: Shufan
authors.initials: S
authors.lastname: Yang
authors.affiliation: Strategic Water Infrastructure Lab, School of Civil, Mining and Environmental Engineering, University of Wollongong, NSW 2522, Australia.
authors.forename: Faisal I
authors.initials: FI
authors.lastname: Hai
authors.affiliation: Strategic Water Infrastructure Lab, School of Chemistry, University of Wollongong, NSW 2522, Australia.
authors.forename: William E
authors.initials: WE
authors.lastname: Price
authors.affiliation: School of Civil and Environmental Engineering, University of New South Wales, NSW 2052, Australia.
authors.forename: James
authors.initials: J
authors.lastname: McDonald
authors.affiliation: School of Civil and Environmental Engineering, University of New South Wales, NSW 2052, Australia.
authors.forename: Stuart J
authors.initials: SJ
authors.lastname: Khan
authors.affiliation: Strategic Water Infrastructure Lab, School of Civil, Mining and Environmental Engineering, University of Wollongong, NSW 2522, Australia. Electronic address: longn@uow.edu.au.
authors.forename: Long D
authors.initials: LD
authors.lastname: Nghiem
mesh_terms: D000693:Anaerobiosis; D056804:Biofuels / Q000032:analysis; D019149:Bioreactors / Q000382:microbiology; D008697:Methane / Q000032:analysis; D009930:Organic Chemicals / Q000302:isolation & purification*; D012722:Sewage / Q000737:chemistry*; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*
chemical_list: D056804:Biofuels; D008697:Methane; D009930:Organic Chemicals; D012722:Sewage; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Anaerobic digestion; Molecular structure; Primary sludge; Sludge retention time (SRT); Trace organic contaminants