title: Simultaneous nitrogen and phosphorus removal in the sulfur cycle-associated Enhanced Biological Phosphorus Removal (EBPR) process.
abstract: Hong Kong has practiced seawater toilet flushing since 1958, saving 750,000 m(3) of freshwater every day. A high sulfate-to-COD ratio (>1.25 mg SO4(2-)/mg COD) in the saline sewage resulting from this practice has enabled us to develop the Sulfate reduction, Autotrophic denitrification and Nitrification Integrated (SANI(®)) process with minimal sludge production and oxygen demand. Recently, the SANI(®) process has been expanded to include Enhanced Biological Phosphorus Removal (EBPR) in an alternating anaerobic/limited-oxygen (LOS-EBPR) aerobic sequencing batch reactor (SBR). This paper presents further development - an anaerobic/anoxic denitrifying sulfur cycle-associated EBPR, named as DS-EBPR, bioprocess in an alternating anaerobic/anoxic SBR for simultaneous removal of organics, nitrogen and phosphorus. The 211 day SBR operation confirmed the sulfur cycle-associated biological phosphorus uptake utilizing nitrate as electron acceptor. This new bioprocess cannot only reduce operation time but also enhance volumetric loading of SBR compared with the LOS-EBPR. The DS-EBPR process performed well at high temperatures of 30 °C and a high salinity of 20% seawater. A synergistic relationship may exist between sulfur cycle and biological phosphorus removal as the optimal ratio of P-release to SO4(2-)-reduction is close to 1.0 mg P/mg S. There were no conventional PAOs in the sludge.
authors.affiliation: Department of Civil & Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong.
authors.forename: Di
authors.initials: D
authors.lastname: Wu
authors.affiliation: Water Research Group, Department of Civil Engineering, University of Cape Town, South Africa.
authors.forename: George A
authors.initials: GA
authors.lastname: Ekama
authors.affiliation: Department of Civil & Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong.
authors.forename: Hai-Guang
authors.initials: HG
authors.lastname: Wang
authors.affiliation: Department of Civil & Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong.
authors.forename: Li
authors.initials: L
authors.lastname: Wei
authors.affiliation: School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Lu
authors.affiliation: Department of Civil & Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong.
authors.forename: Ho-Kwong
authors.initials: HK
authors.lastname: Chui
authors.affiliation: Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
authors.forename: Wen-Tso
authors.initials: WT
authors.lastname: Liu
authors.affiliation: Department of Environmental Engineering and Water Technology, UNESCO-IHE Institute for Water Education, Delft, The Netherlands.
authors.forename: Damir
authors.initials: D
authors.lastname: Brdjanovic
authors.affiliation: Department of Biotechnology, Delft University of Technology, Delft, The Netherlands; KWR Watercycle Research, Nieuwegein, The Netherlands.
authors.forename: Mark C M
authors.initials: MC
authors.lastname: van Loosdrecht
authors.affiliation: Department of Civil & Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong; SYSU-HKUST Joint Research Center for Innovative Environmental Technology, Sun Yat-sen University, Guangzhou, China. Electronic address: ceghchen@ust.hk.
authors.forename: Guang-Hao
authors.initials: GH
authors.lastname: Chen
mesh_terms: D000085:Acetates / Q000032:analysis; D000693:Anaerobiosis; D061249:Batch Cell Culture Techniques; D001673:Biodegradation, Environmental; D019149:Bioreactors / Q000382:microbiology; D007700:Kinetics; D059013:Microbial Consortia; D009566:Nitrates / Q000032:analysis; D009584:Nitrogen / Q000302:isolation & purification*; D010758:Phosphorus / Q000302:isolation & purification*; D013431:Sulfates / Q000032:analysis; D013455:Sulfur / Q000378:metabolism*; D013696:Temperature
chemical_list: D000085:Acetates; D009566:Nitrates; D013431:Sulfates; D010758:Phosphorus; D013455:Sulfur; D009584:Nitrogen
keywords: Denitrification; Enhanced biological phosphorus removal; Saline sewage; Sulfur cycle; Warm temperature