title: Advanced phosphorus recovery using a novel SBR system with granular sludge in simultaneous nitrification, denitrification and phosphorus removal process.
abstract: In this study, a novel process for phosphorus (P) recovery without excess sludge production from granular sludge in simultaneous nitrification-denitrification and P removal (SNDPR) system is presented. Aerobic microbial granules were successfully cultivated in an alternating aerobic-anaerobic sequencing batch reactor (SBR) for removing P and nitrogen (N). Dense and stable granular sludge was created, and the SBR system showed good performance in terms of P and N removal. The removal efficiency was approximately 65.22 % for N, and P was completely removed under stable operating conditions. Afterward, new operating conditions were applied in order to enhance P recovering without excess sludge production. The initial SBR system was equipped with a batch reactor and a non-woven cloth filter, and 1.37 g of CH3COONa·3H2O was added to the batch reactor after mixing it with 1 L of sludge derived from the SBR reactor to enhance P release in the liquid fraction, this comprises the new system configuration. Under the new operating conditions, 93.19 % of the P contained in wastewater was released in the liquid fraction as concentrated orthophosphate from part of granular sludge. This amount of P could be efficiently recovered in the form of struvite. Meanwhile, a deterioration of the denitrification efficiency was observed and the granules were disintegrated into smaller particles. The biomass concentration in the system increased firstly and then maintained at 4.0 ± 0.15 gVSS/L afterward. These results indicate that this P recovery operating (PRO) mode is a promising method to recover P in a SNDPR system with granular sludge. In addition, new insights into the granule transformation when confronted with high chemical oxygen demand (COD) load were provided.
authors.affiliation: CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science and Technology of China, Hefei, 230026, China.
authors.forename: Yong-Ze
authors.initials: YZ
authors.lastname: Lu
authors.affiliation: CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science and Technology of China, Hefei, 230026, China.
authors.forename: Hou-Feng
authors.initials: HF
authors.lastname: Wang
authors.affiliation: Department of Hydraulics, Soil Science and Agricultural Engineering, School of Agriculture, Aristotle University of Thessaloniki, 54124, Thessaloniki, Greece.
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Kotsopoulos
authors.affiliation: CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science and Technology of China, Hefei, 230026, China. rzeng@ustc.edu.cn.
authors.forename: Raymond J
authors.initials: RJ
authors.lastname: Zeng
mesh_terms: D001673:Biodegradation, Environmental; D057919:Biological Oxygen Demand Analysis; D018533:Biomass; D019149:Bioreactors; D058440:Denitrification; D007218:Industrial Microbiology / Q000379:methods*; D058465:Nitrification; D009584:Nitrogen / Q000032:analysis; D010758:Phosphorus / Q000302:isolation & purification*; D012722:Sewage / Q000737:chemistry*; D062065:Wastewater
chemical_list: D009584:Nitrogen; D010758:Phosphorus; D012722:Sewage; D062065:Wastewater
keywords: Denitrification and phosphorus removal; External COD addition; Granular sludge; No residual sludge wastage; Phosphorus recovery; Simultaneous nitrification