title: Large-scale demonstration of the sulfate reduction autotrophic denitrification nitrification integrated (SANI(®)) process in saline sewage treatment.
abstract: Recently, the Sulfate reduction Autotrophic denitrification Nitrification Integrated (SANI(®)) process was developed for the removal of organics and nitrogen with sludge minimization in the treatment of saline sewage (with a Sulfate-to-COD ratio > 0.5 mg SO4(2-)-S/mg COD) generated from seawater used for toilet flushing or salt water intrusion. Previously investigated in lab- and pilot-scale, this process has now been scaled up to a 800-1000 m(3)/d full-scale demonstration plant. In this paper, the design and operating parameters of the SANI demo plant built in Hong Kong are analyzed. After a 4-month start-up period, a stable sulfur cycle-based biological nitrogen removal system having a hydraulic retention time (HRT) of 12.5 h was developed, thereby reducing the amount of space needed by 30-40% compared with conventional activated sludge (CAS) plants in Hong Kong. The demo plant satisfactorily met the local effluent discharge limits during both the summer and winter periods. In winter (sewage temperature of 21 ± 1 °C), the maximum volumetric loading rates for organic conversion, nitrification, and denitrification were 2 kg COD/(m(3)·d), 0.39 kg N/(m(3)·d), and 0.35 kg N/(m(3)·d), respectively. The biological sludge production rate of SANI process was 0.35 ± 0.08 g TSSproduced/g BOD5 (or 0.19 ± 0.05 g TSS/g COD), which is 60-70% lower than that of the CAS process in Hong Kong. While further process optimization is possible, this study demonstrates the SANI process can be potentially implemented for the treatment of saline sewage.
authors.affiliation: Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, China; Water Technology Center, The Hong Kong University of Science and Technology, Hong Kong, China; Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution (Hong Kong Branch), The Hong Kong University of Science and Technology, Hong Kong, China.
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 and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, China.
authors.forename: Ho-Kwong
authors.initials: HK
authors.lastname: Chui
authors.affiliation: Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Wang
authors.affiliation: Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, China.
authors.forename: Yan-Xiang
authors.initials: YX
authors.lastname: Cui
authors.affiliation: Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, China.
authors.forename: Tian-Wei
authors.initials: TW
authors.lastname: Hao
authors.affiliation: Department of Biotechnology, Delft University of Technology, Delft, The Netherlands.
authors.forename: Mark C M
authors.initials: MCM
authors.lastname: van Loosdrecht
authors.affiliation: Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, China; Water Technology Center, The Hong Kong University of Science and Technology, Hong Kong, China; Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution (Hong Kong Branch), The Hong Kong University of Science and Technology, Hong Kong, China; Wastewater Treatment Laboratory, FYT Graduate School, The Hong Kong University of Science and Technology, Nansha, Guangzhou, China. Electronic address: ceghchen@ust.hk.
authors.forename: Guang-Hao
authors.initials: GH
authors.lastname: Chen
mesh_terms: D052818:Autotrophic Processes; D019149:Bioreactors; D058440:Denitrification; D058465:Nitrification; D009584:Nitrogen; D012722:Sewage; D013431:Sulfates; D014865:Waste Disposal, Fluid
chemical_list: D012722:Sewage; D013431:Sulfates; D009584:Nitrogen
keywords: SANI process; Saline sewage treatment; Scale-up; Sludge minimization